Title of the invention: Manufacturing method and manufacturing apparatus for structural members
Technical field
[0001]
The present invention relates to a method for manufacturing a structural member and a manufacturing apparatus.
This application claims priority based on Japanese Patent Application No. 2019-125318 filed in Japan on July 4, 2019, and the contents thereof are incorporated herein by reference.
Background technology
[0002]
Suspension parts, which are structural members of automobile bodies, are important parts that affect the steering stability of automobiles. For example, the front lower arm (hereinafter, may be simply referred to as "lower arm") holds the position and orientation of the tire, holds the lateral force when turning the vehicle, blocks the impact transmission to the body side at the time of impact input, and when riding on a curb. It plays a role of maintaining the strength of the tire. As a result of studies for achieving high performance in these roles, it was concluded that it is important to increase the strength of each part of the lower arm, especially the curved edge part.
[0003]
Patent Documents 1 to 3 disclose processing techniques for processing flat plate materials to increase their strength.
That is, the technique described in Patent Document 1 is a flat plate-shaped processed material having a bottom portion formed on the central portion side in the width direction, left and right side wall portions located on both sides of the bottom portion in the width direction, and these left and right side wall portions. It is a method of forming into a closed cross-section structure including a pair of flange portions formed at the widthwise end portions of the above. The method for forming the closed cross-section structure includes the following steps: the first step of press-molding the processed material into the curvature shape required for the final closed cross-section shape in the longitudinal direction and the width direction; With respect to the processed material formed in the first step, the bottom portion is sandwiched between the first punch and the pad from the plate thickness direction, so that the left and right side wall portions are bent and molded so as to face each other; the second step. With the bottom portion of the processed material formed in the process arranged on the pad, the pair of flange portions are moved toward each other by pushing the pair of pressing cams to move the left and right side wall portions toward each other. A die cavity having the same space shape as the final closed cross-sectional shape is defined by the support surface supporting the bottom portion of the pad and the pushing surface pushing the left and right side wall portions of the pair of pressing cams. At the same time, by pushing down the pair of flanges toward the cavity with the pushing-down portion of the second punch arranged above the pair of flanges, the bottom portion and the left and right side wall portions are formed on the support surface and the support surface of the die cavity. The third step of pressing toward the pushing surface.
[0004]
Further, the technique described in Patent Document 2 is a technique of bending a flat plate-shaped processed material at a position of a plurality of bending lines extending in the longitudinal direction to form a bottom portion of the processed material on the central portion side in the width direction. This is a method of forming into a closed cross-sectional structure including left and right side wall portions located on both sides in the width direction of the bottom portion. The method for forming the closed cross-sectional structure includes the following steps: press molding is performed to form the processed material into a curvature shape required for the final closed cross-sectional shape in the longitudinal direction and the width direction. The first step of applying a bending guide line to a position to be a bending line in the final closed cross-sectional shape; the bottom portion of the processed material formed in the first step is sandwiched between a punch and a pad from the plate thickness direction. A second step of bending and molding the left and right side wall portions in a direction approaching by pushing the punch between the pair of dies; the final step on the bottom portion of the processed material molded in the second step. With the plug having the same outer peripheral shape as the closed cross-sectional shape, the bottom portion and the left and right side wall portions are bent by pressing the bottom portion and the left and right side wall portions against the outer peripheral portion of the plug to bend the bottom portion and the left and right side wall portions with the bending guide line as a boundary. Third step of molding.
[0005]
Further, the technique described in Patent Document 3 is a method of manufacturing a closed cross-section structural member by molding a flat plate-shaped processed material into a closed cross-section structure in which the bottom surface portion is curved along the longitudinal direction. The method for manufacturing the closed cross-section structural member includes the following steps: the first out-of-plane deformation portion each having a concave shape or a convex shape is formed in the longitudinal direction with respect to at least the bottom surface portion position of the processed material. In the first forming step of forming a plurality of bending portions along the above; The second molding step of crushing the first out-of-plane deformed portion and bending and molding the bent portion.
[0006]
Further, the technique described in Patent Document 4 is a die including a punch, a blank holder arranged adjacent to the punch, a die shoulder and a plate holding surface, and is along the extending direction of the die shoulder. A press device including a die in which a part of the die shoulder is curved in a concave shape. Then, in this press device, the die shoulder boundary line defined by the R stop on the plate holding surface side of the die shoulder in the region other than the concavely curved region of the die shoulder, and the edge of the blank holder. , Is wider than the horizontal distance between the die shoulder boundary line and the edge of the blank holder in the concavely curved region of the die shoulder.
[0007]
Further, the technique described in Patent Document 5 is a plate-shaped main body portion arranged substantially parallel to a load input surface, and a substantially pipe-shaped reinforcing portion continuously provided along at least one side edge of the main body portion. It is a suspension arm for vehicles equipped with.
[0008]
Further, the technique described in Patent Document 6 includes a top plate portion having a first edge portion and a second edge portion facing the first edge portion, and the top plate portion from the second edge portion to the top plate portion. It is a structural member having a wall portion extending in an intersecting direction and the closed cross-sectional portion provided on the first edge portion. In this structural member, the first edge portion is curved toward the inside of the top plate portion in a plan view with respect to the top plate portion, and the first edge portion of the structural member to the second edge portion. When the distance to the structural member width is taken as the structural member width, the closed cross section is provided inside the curve of the top plate portion and forms a closed cross section in the vertical cross section of the structural member along the direction of the structural member width. The vertical cut surface of the structural member along the direction of the structural member width has an open cross section, and the shape of the vertical cut surface of the structural member including the closed cross section is relative to the center of the length of the structural member width. Is asymmetric.
Prior art literature
Patent documents
[0009]
Patent Document 1: Japanese Unexamined Patent Publication No. 2013-24511
Patent Document 2: Japanese Unexamined Patent Publication No. 2013-24512
Patent Document 3: Japanese Unexamined Patent Publication No. 2012-152765
Patent Document 4: Japanese Unexamined Patent Publication No. 2017-1278998
Patent Document 5: Japanese Unexamined Patent Publication No. 8-188022
Patent Document 6: International Publication No. 2019/103152
Outline of the invention
Problems to be solved by the invention
[0010]
However, none of the techniques disclosed in Patent Documents 1 to 5 is a technique capable of forming a curved reinforcing portion at a position away from the neutral axis, such as a curved edge of a lower arm. The neutral axis referred to here is an axis that passes through the center position between the curved edge of the lower arm and the edge on the opposite side of the curved edge.
[0011]
In particular, it was difficult to form a reinforcing portion having a bend with a small radius of curvature along the edge portion while leaving the flat plate-shaped top plate portion such as the curved edge of the lower arm. For example, when the techniques of Patent Documents 1 to 5 are to be applied, it is conceivable to manufacture another tubular part based on the disclosed techniques and weld the other part to the curved edge to form a reinforcing portion. An example thereof is disclosed in Patent Document 6. However, welding another part to a curved edge to form a reinforcing portion has a problem from the viewpoint of welding workability and manufacturing cost. In the first place, it is difficult to form a reinforcing portion having a small radius of curvature by using the techniques disclosed in Patent Documents 1 to 6, and there is a possibility that a partial crushing of the cross-sectional shape may occur when viewed along the longitudinal direction thereof. Is high. Further, even if the core is used to prevent crushing, there is a high possibility that the core will not come off after molding.
[0012]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a structural member and a manufacturing apparatus capable of reinforcing the curved edge of a top plate portion without using a separate part.
Means to solve problems
[0013]
The present invention employs the following means in order to solve the above problems and achieve the above object.
(1) In the method for manufacturing a structural member according to one aspect of the present invention, a top plate portion having a curved edge is integrally formed with the top plate portion along the extending direction of the curved edge, and the curved edge is formed. It is a method of manufacturing a structural member having a curved reinforcing portion having a closed cross-section shape or an open cross-section shape in a cross section orthogonal to the extending direction from a flat plate material, and corresponds to the top plate portion of the flat plate material. By pressing the second portion connected to the first portion in a direction intersecting the surface of the flat plate material while sandwiching the first portion to be formed, the curved edge of the flat plate material is obtained. An intermediate step of forming a groove portion and a vertical wall portion connected to the groove portion along the portion; after the intermediate step, the upper end edge of the vertical wall portion is moved to the groove portion while allowing movement toward the top plate portion. It has a bending step of bending the upper end edge toward the top plate portion by pushing down toward the top plate portion; and in the intermediate step, by the press, the bottom wall of the groove portion is formed along the extending direction of the groove portion. By providing a height difference between the intermediate position in the vertical cross-sectional view and the adjacent positions sandwiching the intermediate position in between, the bottom wall has a concave curved shape in a plan view and a convex curved shape in the vertical cross-sectional view. At least one of a first curved portion to be formed and a second curved portion having a convex curved shape in a plan view and a concave curved shape in the vertical cross-sectional view is formed.
[0014]
According to the method for manufacturing a structural member according to the above (1), at least one of a first curved portion and a second curved portion is formed on a bottom wall viewed in a vertical cross section along a extending direction by a press in an intermediate step. Since it is provided, the bending in the same direction as the bending direction of the bending reinforcing portion of the structural member can be imparted to the bottom wall before the next step. In addition, by bending the bottom wall so as to form at least one of the first curved portion and the second curved portion, the upper end edge of the vertical wall portion connected to the bottom wall is deformed by an extension flange or a contraction flange. Can be done. Due to the expansion flange deformation or the contraction flange deformation, the vertical wall portion can be tilted so that the upper end edge thereof approaches the first portion, so that the vertical wall portion can be easily bent in the subsequent bending step. Therefore, a curved reinforcing portion having a closed cross-sectional shape or an open cross-sectional shape can be formed without using a core, and the rigidity of the structural member can be increased. Here, two points are pointed out: that the shape of the curved reinforcing portion can be formed without breaking the shape during the bending process, and that cracking does not occur. In the above aspect, in the intermediate step, the vertical wall portion is pre-deformed by extension flange deformation or contraction flange deformation, and the deformation range of the material is not limited locally but is performed in a wide range. As a result, the above two points can be achieved.
At the time of press molding in the intermediate process, the first part corresponding to the top plate part is not completely fixed but is in a sandwiched state. Therefore, the first portion is restricted from moving and deforming out of the plane, but a metal flow in which a part of the first portion is directed to the second portion is allowed.
[0015]
When the first curved portion having a concave curved shape in a plan view and a convex curved shape in the vertical cross-sectional view is formed on the bottom wall by the press in the intermediate step, the curved reinforcing portion has a plan view. Can form a concave portion with. Further, when the second curved portion having a convex curved shape in a plan view and a concave curved shape in the vertical cross-sectional view is formed on the bottom wall by the press in the intermediate step, the curved reinforcing portion is formed. A convex portion can be formed in a plan view. Here, the first curved portion and the second curved portion may be a part or the whole of the bottom wall, respectively.
Then, after the bending process, if the upper end edge is joined to the top plate portion, a reinforcing portion having a closed cross-sectional shape is formed. Further, if the upper end edge is kept away from the top plate portion after the bending step, a curved reinforcing portion having an open cross-sectional shape is formed.
[0016]
The above-mentioned "curved" shape is not limited to an arc shape having a constant radius of curvature, and may include a curved shape that is not an arc shape such as an elliptical shape or a radial shape. Further, the curved shape may include a linear shape as a part. Further, the "curved" shape may be either a symmetrical shape or an asymmetrical shape with the central position in the longitudinal direction as a boundary in a plan view.
[0017]
(2) In the embodiment described in (1) above.When the cross-sectional line length along the inner shape of the cross section of the groove portion orthogonal to the extending direction of the groove portion is viewed by the press in the intermediate step, the cross-sectional line length at the intermediate position is used. The ratio divided by the cross-sectional line lengths at both adjacent positions may be in the range of 0.7 to 1.3.
In the case of the embodiment described in (2) above, the sizes of the cross-sectional shapes at each position along the extending direction of the curved reinforcing portion can be made substantially equal. In addition, it is possible to prevent molding defects such as cracks and wrinkles from occurring in the portion of the curved reinforcing portion that overlaps the top plate portion in a plan view.
[0018]
(3) In the embodiment described in (1) or (2) above, in the plan view of the bottom wall in at least one of the first curved portion and the second curved portion by the press in the intermediate step. The R / R1 ratio obtained by dividing the radius of curvature R (mm) of the center line passing through the center position in the width direction by the radius of curvature R1 (mm) in the vertical cross-sectional view of the bottom wall is in the range of 0.2 to 1.2. It may be inside.
In the case of the embodiment described in (3) above, it is possible to prevent the height difference between the first curved portion and the second curved portion after the intermediate step from being excessively large or small. As a result, it is possible to avoid the occurrence of defects such as dimensional defects, constrictions, and breaks in the curved reinforcing portion.
When a plurality of first curved portions or second curved portions are included, the radius of curvature R and R1 adopt the combination of the radii of curvature R and R1 at the position having the smallest value among the radii of curvature R.
[0019]
(4) In the embodiment according to any one of (1) to (3) above, after the bending step, at least a part of the upper end edge of the vertical wall portion is overlapped with the top plate portion and joined. , Further may have a joining step of forming the curved reinforcing portion having the closed cross-sectional shape.
In the case of the embodiment described in (4) above, a curved reinforcing portion having a closed cross-sectional shape can be formed along the curved edge of the top plate portion.
[0020]
(5) In the embodiment described in (4) above, in the joining step, the movement of the upper end edge beyond the planned joining position on the top plate portion may be restricted.
In the case of the embodiment described in (5) above, the upper end edge of the vertical wall portion is subjected to a force for restricting movement beyond the planned joining position. Since the vertical wall portion obtained by using this force as a reaction force is deformed so that its cross-sectional shape swells, an appropriate closed cross-sectional shape can be formed without using a core.
[0021]
(6) In the embodiment according to (4) or (5) above, the upper end edge bending step of forming a bent portion in which the upper end edge toward the top plate portion during the joining step is formed before the joining step is further performed. You may have.
In the case of the embodiment described in (6) above, by forming a bent portion on the upper end edge in advance, a surface that pressurizes the upper end edge (for example, a pressed surface of a mold) when the upper end edge is pushed down to bend the vertical wall portion. ) Can be reduced.
[0022]
(7) In the embodiment according to any one of (1) to (3) above, in the bending step, at least a part of the upper end edge is on the top plate portion in a plan view facing the top plate portion. On the other hand, even if the folding step of forming the curved reinforcing portion having the open cross-sectional shape is included by further bending the vertical wall portion until the upper end edge is separated from the top plate portion in the side view. good.
In the case of the embodiment described in (7) above, a curved reinforcing portion having an open cross-sectional shape can be formed along the curved edge of the top plate portion.
[0023]
(8) In the embodiment described in (7) above, when the vertical wall portion is further bent in the folding step, the movement of the upper end edge beyond a predetermined position may be restricted.
In the case of the embodiment described in (8) above, the upper end edge of the vertical wall portion is subjected to a force for restricting movement beyond a predetermined position. Since the vertical wall portion obtained by using this force as a reaction force is deformed so that its cross-sectional shape swells, an appropriate open cross-sectional shape can be formed without using a core.
[0024]
(9) In the embodiment according to (7) or (8) above, the upper end edge bending step of forming a bent portion in which the upper end edge toward the top plate portion during the folding step is formed before the folding step is further performed. You may have.
In the case of the embodiment described in (9) above, by forming a bent portion on the upper end edge in advance, a surface that pressurizes the upper end edge (for example, a pressed surface of a mold) when the upper end edge is pushed down to bend the vertical wall portion. ) Can be reduced.
[0025]
(10) In the embodiment according to any one of (1) to (9) above, the bending is performed by forming both the first bending portion and the second bending portion by the press in the intermediate step. After the step, the curved reinforcing portion including both the concave curved shape and the convex curved shape may be formed in a plan view facing the top plate portion.
In the case of the embodiment described in (10) above, it is possible to obtain a structural member having a plurality of curved shapes (concavo-convex shapes) in the same curved reinforcing portion.
[0026]
(11) The apparatus for manufacturing a structural member according to one aspect of the present invention is integrally formed with a top plate portion having a curved edge and the top plate portion along the extending direction of the curved edge, and the curved edge is formed. A device for manufacturing a structural member having a curved reinforcing portion having a closed cross-sectional shape having a cross section orthogonal to the extending direction from a flat plate material, wherein a first mold groove curved in a plan view is formed. A die; a first punch that is relatively close to and separated from the first die groove; a second die groove that has a second die groove that is thinner than the first die groove in plan view. With the die; with the first holder having a curved convex portion having a shape corresponding to the second mold groove; in a plan view, 5 mm or more and 50 mm or less in the horizontal direction with respect to the first vertical wall surface of the first holder. It has a second vertical wall surface that is arranged so as to face each other with a distance of the above, and is arranged so as to overlap the second die with a second punch that is relatively close to and separated from the second mold groove. A second holder; a pad having a pressure surface that is close to and separated from the second mold groove; and a bottom surface of the first mold groove is an extension of the first mold groove. There is a height difference between the intermediate position viewed in a vertical cross section along the current direction and the adjacent positions sandwiching the intermediate position, and the pressure surface of the first punch is the pressure surface of the first die groove. A first mold curved surface having a height difference corresponding to the bottom surface, and the bottom surface of the first mold groove has a concave curved shape in the plan view and a convex curved shape in the vertical cross-sectional view, and It has at least one of the second mold curved surfaces having a convex curved shape in the plan view and a concave curved shape in the vertical cross-sectional view, and has a first top plate support surface of the second die. The gap at the bottom dead point of molding is larger on the pressurized surface of the pad than on the pressurized surface of the second holder.
[0027]
According to the structural member manufacturing apparatus according to (11) above, the curved reinforcing portion of the structural member is formed by sandwiching a flat plate material between the first metal groove and the pressure surface of the first punch. A groove having a bottom wall of bending in the same direction as the bending direction can be previously provided to the flat plate material. In addition, since the flat plate material can be bent so as to impart the uneven shape corresponding to the curved surface of the first mold and the curved surface of the second mold to the bottom wall of the groove portion, the upper end edge of the vertical wall portion connected to the bottom wall can be bent. The extension flange can be deformed or the contraction flange can be deformed. By this expansion flange deformation or contraction flange deformation, the vertical wall portion can be tilted so that the upper end edge thereof approaches the portion to be the top plate portion, so that it becomes easy to bend the vertical wall portion in the next step. .. The "corresponding height difference" on the pressure surface of the first punch means the height difference formed by bending the pressure surface of the first punch in the same direction as the bottom surface of the first die groove. It is preferable that the height difference is the same as that of the first mold groove.
[0028]
When the bottom surface of the first mold groove includes a first mold curved surface having a concave curved shape in a plan view and a convex curved shape in a vertical cross-sectional view, the curved reinforcing portion has a concave shape in a plan view. Parts can be formed. Further, when the bottom surface of the first mold groove includes a second mold curved surface having a convex curved shape in a plan view and a concave curved shape in a vertical cross-sectional view, the curved reinforcing portion is used in a plan view. Convex portions can be formed. Here, in the first curved portion and the second curved portion, the first curved surface and the second curved surface of the mold are all even if they are a part of the bottom surface of the first mold groove, respectively. May be good.
[0029]
Then, as described above, the structural member manufacturing apparatus includes a second die, a first holder, and a second punch. According to this configuration, after the groove portion and the vertical wall portion are formed in the flat plate material by the first die and the first punch, the groove portion is sandwiched between the second mold groove and the curved convex portion. The flat plate material is sandwiched between the second die and the first holder. Then, by bringing the second punch closer to the flat plate material, the bottom wall of the groove can be bent. As a result, a part of the bottom wall becomes a part of the vertical wall portion, and a bend to be used in the next step can be provided in advance between the part of the bottom wall and the original vertical wall portion. ..
[0030]
And, as mentioned above, the manufacturing apparatus of the structural member further includes a second holder and a pad. In addition, the gap at the bottom dead center of molding with respect to the first top plate support surface of the second die is larger on the pressure surface of the pad than on the pressure surface of the second holder. According to this configuration, the bottom wall partially bent by the second punch is housed in the second mold groove and the third mold groove, and then the second die and the second holder are used. Insert a flat plate material between them. Then, by pressing the pressure surface of the pad against the upper end edge of the vertical wall portion, the vertical wall portion is bent and brought into contact with the top plate portion in the gap between the second die and the pad to reinforce the curvature of the closed cross-sectional shape. The part can be formed. Here, the gap at the bottom dead center of molding with respect to the first top plate support surface of the second die is larger on the pressure surface of the pad than on the pressure surface of the second holder. Therefore, in the second holder, the top plate portion is firmly sandwiched, and in the pad, a joining allowance for sandwiching the upper end edge of the top plate portion and the vertical wall portion with the second die is obtained. Can be done.
[0031]
(12) In the aspect described in (11) above, the cross-sectional line length of the first mold groove along the inner shape in the cross section orthogonal to the extending direction of the first mold groove is seen. Occasionally, the ratio of the cross-sectional line length at the intermediate position divided by the cross-sectional line length at both adjacent positions may be in the range of 0.7 to 1.3.
In the case of the embodiment described in (12) above, in the structural member obtained by the manufacturing apparatus for the structural member, the sizes of the cross-sectional shapes at each position along the extending direction of the curved reinforcing portion can be made substantially equal. .. In addition, it is possible to prevent molding defects such as cracks and wrinkles from occurring in the portion of the curved reinforcing portion that overlaps the top plate portion in a plan view.
[0032]
(13) In the embodiment described in (11) or (12) above, at least one of the curved surface of the first mold and the curved surface of the second mold on the bottom surface of the first mold groove. The R / R1 ratio obtained by dividing the radius of curvature R (mm) of the center line passing through the center position in the width direction in the plan view with the radius of curvature R1 (mm) in the vertical cross-sectional view is in the range of 0.2 to 1.2. It may be inside.
In the case of the embodiment described in (13) above, when the flat plate material is molded, the height difference formed by the curved surface of the first mold or the curved surface of the second mold is excessively large or small. Can be prevented. As a result, it is possible to avoid the occurrence of defects such as dimensional defects, constrictions, and breaks in the curved reinforcing portion.
When the bottom surface of the first mold groove includes a plurality of curved surfaces of the first mold and the curved surface of the second mold, the radii of curvature R and R1 are the curvatures at the positions having the smallest value among the radii of curvature R. The radii R and R1 are adopted.
[0033]
(14) The apparatus for manufacturing a structural member according to another aspect of the present invention is integrally formed with a top plate portion having a curved edge and the top plate portion along the extending direction of the curved edge, and is curved. A device for manufacturing a structural member from a flat plate material having a curved reinforcing portion having an open cross-sectional shape in a cross section orthogonal to the extending direction of the edge, the first including a first mold curved edge curved in a plan view. A third die having two top plate support surfaces; a third holder that is close to and separated from the second top plate support surface; and placed adjacent to the first mold curved edge in a plan view. A fourth die having a fourth mold groove; a fourth punch approaching and separating from the fourth mold groove; a third including a second mold curved edge curved in a plan view. With a fifth die having a top plate support surface; with a fourth holder approaching and separating from the third top plate support surface; in plan view, horizontal to the third vertical wall surface of the fourth holder. 5 mm or more in the direction A fifth punch having a fourth vertical wall surface facing each other with a distance of 50 mm or less above; a sixth having a fourth top plate support surface including a third mold curved edge curved in a plan view. With a die; with a fifth holder approaching and separating from the fourth top plate support surface; with a pressure surface overlapping on the curved edge of the third mold in a plan view, the sixth die. With a sixth punch that is close to and separated from each other; There is a height difference between the adjacent positions sandwiched between them; the pressure surface of the fourth punch has a height difference corresponding to the bottom surface of the fourth mold groove, and the fourth mold has a height difference. The bottom surface of the groove has a concave curved shape in the plan view and a convex curved shape in the vertical cross-sectional view, and a convex curved surface in the plan view and a convex curved shape in the vertical cross-sectional view. The fifth holder has at least one of the curved surfaces of the fourth mold having a concave curved shape, and the gap at the bottom dead point of molding with respect to the fourth top plate supporting surface of the sixth die is the fifth holder. The pressurized surface of the sixth punch is larger than the pressurized surface of the sixth punch.
[0034]
According to the structural member manufacturing apparatus described in (14) above, the curved reinforcing portion of the structural member is formed by sandwiching a flat plate material between the fourth metal groove and the pressure surface of the fourth punch. A groove having a bottom wall of bending in the same direction as the bending direction can be previously provided to the flat plate material. In addition, since the flat plate material can be bent so as to impart the uneven shape corresponding to the curved surface of the third mold and the curved surface of the fourth mold to the bottom wall of the groove portion, the upper end edge of the vertical wall portion connected to the bottom wall can be bent. The extension flange can be deformed or the contraction flange can be deformed. By this expansion flange deformation or contraction flange deformation, the vertical wall portion can be tilted so that the upper end edge thereof approaches the portion to be the top plate portion, so that it becomes easy to bend the vertical wall portion in the next step. .. The "corresponding height difference" on the pressure surface of the fourth punch means the height difference formed by bending the pressure surface of the fourth punch in the same direction as the bottom surface of the fourth mold groove. It is preferable that the height difference is the same as that of the fourth mold groove.
[0035]
When the bottom surface of the fourth mold groove includes a third mold curved surface having a concave curved shape in a plan view and a convex curved shape in a vertical cross-sectional view, the curved reinforcing portion has a concave shape in a plan view. Parts can be formed. Further, when the bottom surface of the fourth mold groove includes a fourth mold curved surface having a convex curved shape in a plan view and a concave curved shape in a vertical cross-sectional view, the curved reinforcing portion is used in a plan view. Convex portions can be formed.
[0036]
And, as described above, the manufacturing apparatus for the structural member includes a fifth die, a fourth holder, and a fifth punch. According to this configuration, after forming a groove portion and a vertical wall portion in the flat plate material by the fourth die and the fourth punch, the flat plate portion is sandwiched between the fifth die and the fourth holder. The material is sandwiched between the fifth die and the fourth holder. Then, by bringing the fifth punch closer to the flat plate material, the bottom wall of the groove can be bent. As a result, a part of the bottom wall becomes a part of the vertical wall portion, and a bend to be used in the next step can be provided in advance between the part of the bottom wall and the original vertical wall portion. ..
[0037]
And, as described above, the manufacturing apparatus for the structural member includes a sixth die, a fifth holder, and a sixth punch. In addition, the gap at the bottom dead center of molding with respect to the fourth top plate support surface of the sixth die is larger on the pressure surface of the sixth punch than on the pressure surface of the fifth holder. According to this configuration, the upper end edge of the vertical wall portion is held on the pressure surface of the sixth punch while the flat plate material after forming the vertical wall portion is sandwiched between the sixth die and the fifth holder. Push down by. As a result, the vertical wall portion is bent to form a curved reinforcing portion having an open cross-sectional shape. Here, the gap at the bottom dead center of molding with respect to the fourth top plate support surface of the sixth die is larger on the pressure surface of the sixth punch than on the pressure surface of the fifth holder. Therefore, in the fifth holder, the top plate portion is firmly sandwiched, and in the sixth punch, a curved reinforcing portion having an open cross-sectional shape can be obtained between the fifth holder and the sixth die.
[0038]
(15) In the embodiment described in (14) above, the cross-sectional line length of the fourth mold groove along the inner shape in the cross section orthogonal to the extending direction of the fourth mold groove is seen. Occasionally, the ratio of the cross-sectional line length at the intermediate position divided by the cross-sectional line length at both adjacent positions may be in the range of 0.7 to 1.3.
In the case of the embodiment described in (15) above, in the structural member obtained by the manufacturing apparatus for the structural member, the sizes of the cross-sectional shapes at each position along the extending direction of the curved reinforcing portion can be made substantially equal. .. In addition, it is possible to prevent molding defects such as cracks and wrinkles from occurring in the portion of the curved reinforcing portion that overlaps the top plate portion in a plan view.
[0039]
(16) In the embodiment described in (14) or (15) above, at least one of the curved surface of the third mold and the curved surface of the fourth mold on the bottom surface of the fourth mold groove. The R / R1 ratio obtained by dividing the radius of curvature R (mm) of the center line passing through the center position in the width direction in the plan view with the radius of curvature R1 (mm) in the vertical cross-sectional view is in the range of 0.2 to 1.2. It may be inside.
In the case of the embodiment described in (16) above, when the flat plate material is molded, the height difference formed by the curved surface of the third mold or the curved surface of the fourth mold is excessively large or small. Can be prevented. As a result, it is possible to avoid the occurrence of defects such as dimensional defects, constrictions, and breaks in the curved reinforcing portion.
When the bottom surface of the fourth mold groove includes a plurality of curved surfaces of the third mold and the curved surface of the fourth mold, the radii of curvature R and R1 are the curvatures at the positions having the smallest value among the radii of curvature R. The radii R and R1 are adopted.
The invention's effect
[0040]
According to the method and apparatus for manufacturing a structural member according to each of the above aspects, it is possible to reinforce the curved edge to manufacture a structural member having high rigidity.
A brief description of the drawing
[0041]
1A and 1B are views showing a structural member manufactured by the method for manufacturing a structural member according to the first embodiment of the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a plan view.
FIG. 2 is a diagram showing a comparative example to be compared when explaining the effect of the same embodiment, and is a perspective view of each mold and a blank used in the first step.
3A and 3B are views showing the shape of the bottom surface of the die groove used in the comparative example, in which FIG. 3A is a view taken along the line AA of FIG. 3B, and FIG. 3B is orthogonal to the longitudinal direction. It is a side view seen from the direction.
4A and 4B are views showing a blank formed in the first step of the comparative example, in which FIG. 4A is a perspective view and FIG. 4B is a view taken along the line BB in FIG. 4A.
5 is a view showing a blank after the first step of the same comparative example, and is a view taken along the line CC of FIG. 4 (a).
FIG. 6A is a perspective view of each mold used in the second step of the comparative example and the second step of the first embodiment. (B) is a diagram for explaining the relative positional relationship in the horizontal direction between the holder and the punch used in the second step of the first embodiment, and is a vertical cross-sectional view at the center position in the extending direction of the die groove m1. ..
7A and 7B are views showing a blank after the second step of the comparative example, in which FIG. 7A is a perspective view and FIG. 7B is a view taken along the line DD of FIG. 7A.
FIG. 8 is a perspective view of each mold used in the third step of the comparative example and the third step of the first embodiment.
FIG. 9 is a diagram showing a blank shape before starting the third step of the comparative example, and is a view taken along the line EE of FIG. 7 (a).
10A and 10B are views showing a blank in the third step of the comparative example, in which FIG. 10A is a perspective view and FIG. 10B is a view taken along the line FF of FIG. 10A.
FIG. 11 is a perspective view in which the shape changes of the blanks from the second step to the third step of the comparative example are arranged in the order of (a) to (f) in chronological order.
FIG. 12 is a perspective view of each mold and blank used in the first step in the first embodiment of the present invention.
13A and 13B are views showing the shape of the bottom surface of the die groove used in the same embodiment, in which FIG. 13A is a view taken along the line GG of FIG. 13B, and FIG. 13B is orthogonal to the longitudinal direction. It is a side view seen from the direction.
14A and 14B are views showing a blank formed in the first step of the same embodiment, where FIG. 14A is a perspective view and FIG. 14B is an arrow view taken along the line HH of FIG. 14A.
FIG. 15 is a diagram showing a blank after the first step of the same embodiment, and is a view taken along the line II of FIG. 14 (a).
16A and 16B are views showing a blank after the second step of the same embodiment, in which FIG. 16A is a perspective view and FIG. 16B is a JJ arrow view of FIG. 16A.
FIG. 17 is a diagram showing a blank shape before starting the third step of the same embodiment, and is a view taken along the line KK of FIG. 16 (a).
18A and 18B are views showing a blank after the third step of the same embodiment, in which FIG. 18A is a perspective view and FIG. 18B is an arrow view of LL in FIG. 18A.
FIG. 19 is a view showing a modified example of the same embodiment, and is a cross-sectional view taken along the line MM shown in FIG. 18A of a blank in the third step.
FIG. 20 is a perspective view in which the shape changes of the blanks from the second step to the third step of the comparative example are arranged in the order of (a) to (f) in chronological order.
21A and 21B are views showing a structural member manufactured by the method for manufacturing a structural member according to a second embodiment of the present invention, in which FIG. 21A is a perspective view and FIG. 21B is a plan view.
FIG. 22 is a perspective view of each mold and blank used in the first step in the same embodiment.
FIG. 23 is a diagram showing the shape of the bottom surface of the die groove used in the same embodiment, in which (a) is an arrow view of NN of (b), and (b) is orthogonal to the longitudinal direction. It is a side view seen from the direction.
FIG. 24 is a view showing a blank formed in the first step of the same embodiment, in which (a) is a perspective view and (b) is an OO arrow view of (a).
FIG. 25 is a diagram showing a blank after the first step of the same embodiment, and is a view taken along the line PP of FIG. 24 (a).
FIG. 26 is a perspective view of each mold used in the second step of the same embodiment.
27 is a view showing a blank after the second step of the same embodiment, where FIG. 27A is a perspective view and FIG. 27B is a QQ arrow view of FIG. 27A.
FIG. 28 is a perspective view of each mold used in the third step of the same embodiment.
FIG. 29 is a diagram showing a blank shape before starting the third step of the same embodiment, and is a view taken along the line RR of FIG. 27 (a).
30A and 30B are views showing a blank after the third step of the same embodiment, where FIG. 30A is a perspective view and FIG. 30B is an arrow view of SS of FIG. 30A.
FIG. 31 is a view showing a modified example of the same embodiment, and is a cross-sectional view of a blank in the third step as seen by the TT line shown in FIG. 30 (a).
FIG. 32 is a perspective view in which the shape changes of the blank from the second step to the third step of the same embodiment are arranged in the order of (a) to (f) in chronological order.
FIG. 33 is a perspective view showing a structural member manufactured by the method for manufacturing a structural member according to a third embodiment of the present invention.
FIG. 34 is a schematic view illustrating a method of manufacturing a structural member according to the same embodiment, and is a perspective view in which the shape changes of the blank are arranged in the order of (a) to (c) in chronological order.
35 is a diagram showing a first step of a method for manufacturing a structural member according to the same embodiment, where FIG. 35A is a perspective view of each mold used in the same step, and FIG. 35B is a perspective view of a blank. (C) is a side view of the blank as seen from the arrow U1 of (b).
36 is a diagram showing a second step of the method for manufacturing a structural member according to the same embodiment, where FIG. 36A is a perspective view of each mold used in the same step, and FIG. 36B is a perspective view of a blank. (C) is a side view of the blank as seen from the arrow U2 of (b).
37A and 37B are views showing a third step of the method for manufacturing a structural member according to the same embodiment, in which FIG. 37A is a perspective view of each mold used in the same step, and FIG. 37B is a perspective view of a blank. (C) is a side view of the blank as seen from the arrow U3 of (b).
FIG. 38 is a perspective view in which the shape changes of blanks in the method for manufacturing structural members according to the same embodiment are arranged in chronological order in the order of (a) to (i).
FIG. 39 is a perspective view showing a structural member manufactured by the method for manufacturing a structural member according to a fourth embodiment of the present invention.
FIG. 40 is a schematic view illustrating a method for manufacturing a structural member according to the same embodiment, in which the shape change of a blank is changed in the order of (a) to (c).It is a perspective view arranged in a row.
41 is a diagram showing a first step of a method for manufacturing a structural member according to the same embodiment, where FIG. 41A is a perspective view of each mold used in the same step, and FIG. 41B is a perspective view of a blank. (C) is a side view of the blank as seen from the arrow V1 of (b).
42 is a diagram showing a second step of the method for manufacturing a structural member according to the same embodiment, where FIG. 42A is a perspective view of each mold used in the same step, and FIG. 42B is a perspective view of a blank. (C) is a side view of the blank as seen from the arrow V2 of (b).
FIG. 43 is a diagram showing a third step of the method for manufacturing a structural member according to the same embodiment, in which (a) is a perspective view of each mold used in the same step, and (b) is a blank perspective view. (C) is a side view of the blank as seen from the arrow V3 of (b).
FIG. 44 is a perspective view in which the shape changes of blanks in the method for manufacturing a structural member according to the same embodiment are arranged in chronological order in the order of (a) to (i).
45 is a view showing a blank after an intermediate step in the first embodiment, in which (a) is a side view seen from the arrow XX of (b), and (b) is a front view. ..
[Fig. 46] Fig. 46 is a view showing a structural member according to the first embodiment, in which (a) is a side view seen from the arrow YY of (b), and (b) is a front view.
47 is a view showing a blank after the intermediate step in the second embodiment, in which (a) is a side view seen from the arrow of X1-X1 of (b), and (b) is a front view. ..
48 is a view showing a structural member in the second embodiment, in which FIG. 48A is a side view seen from the arrow of Y1-Y1 of FIG. 48B, and FIG. 48B is a front view.
Embodiment for carrying out the invention
[0042]
Each embodiment and embodiment of the manufacturing method and the manufacturing apparatus of the structural member of the present invention will be described below with reference to the drawings.
[0043]
[First Embodiment]
In this embodiment, a manufacturing method and a manufacturing apparatus for molding the structural member 1 shown in FIG. 1 from a flat plate material will be described. Note that FIG. 1 is a diagram showing a structural member 1 manufactured by the method for manufacturing a structural member according to the present embodiment, in which FIG. 1A is a perspective view and FIG. 1B is a plan view.
The structural member 1 shown in FIG. 1 has a top plate portion 2 having a curved edge 2a and a cross section formed integrally with the top plate portion 2 along the extending direction of the curved edge 2a and orthogonal to the extending direction. It has a curved reinforcing portion 3 having a closed cross-sectional shape. In addition, in FIG. 1A, in order to make the shapes of the curved edge 2a and the curved reinforcing portion 3 easy to understand, the joint portion is slightly opened and shown, but in reality, there is no gap at the joint portion. It is joined and the curved reinforcing portion 3 forms a closed cross-sectional shape. It may be illustrated in other drawings as well.
[0044]
The top plate portion 2 has a pair of side edges 2b and 2c parallel to each other, the curved edge 2a connected between the side edges 2b and 2c and forming a leading edge, and the curved edges 2a facing the curved edges 2a and both sides 2b. It is a flat plate partitioned by a trailing edge 2d connected between 2c and 2c. Of these, the both side edges 2b and 2c and the trailing edge 2d each have a linear shape. On the other hand, the curved edge 2a has a concave curved shape whose center is closer to the trailing edge 2d than both ends thereof. The radius of curvature R of this concave curved shape in a plan view is exemplified by 100 mm to 400 mm. However, the radius of curvature R is not limited to this range.
[0045]
The curved reinforcing portion 3 is connected to the inner wall 3a which is connected to the curved edge 2a of the top plate portion 2 and goes vertically downward, the bottom wall 3b which is connected to the inner wall 3a and is oriented horizontally away from the top plate portion 2, and the bottom wall 3b. It is provided with an outer wall 3c that is connected and vertically upwards, and an upper wall 3d that is connected to the outer wall 3c and joined to the upper surface 2e of the top plate portion 2.
The height dimension of the inner wall 3a in the vertical direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 3. The inner wall 3a has a concave curved shape having the same radius of curvature in the same direction as the curved edge 2a in a plan sectional view.
The width dimension of the bottom wall 3b in the horizontal direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 3. The bottom wall 3b is parallel to the top plate portion 2 in the side view, and has a concave curved shape bent in the same direction as the curved edge 2a in the bottom view.
[0046]
The height dimension of the outer wall 3c in the vertical direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 3. The outer wall 3c has a concave curved shape that is curved in the same direction as the curved edge 2a in a plan sectional view.
The width dimension of the upper wall 3d in the horizontal direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 3, and is wider than the bottom wall 3b. The upper wall 3d is parallel to the top plate portion 2 in the vertical cross-sectional view, and has a concave curved shape curved in the same direction as the curved edge 2a in the plan view. The upper wall 3d is joined to the upper surface 2e of the top plate portion 2 at a position beyond the curved edge 2a toward the trailing edge 2d. As the joining means, for example, welding, adhesion, bolt fixing and the like can be appropriately used.
[0047]
The inner wall 3a and the outer wall 3c are parallel to each other, and the upper wall 3d and the bottom wall 3b are parallel to each other. A closed cross-sectional shape is formed by the four wall portions of the inner wall 3a, the bottom wall 3b, the outer wall 3c, and the upper wall 3d. That is, in the present embodiment, a concave curved space is formed in the curved reinforcing portion 3, and the space is provided only at two locations, one end and the other end along the extending direction of the curved reinforcing portion 3. It communicates with the outside.
According to the structural member 1 having the above-described configuration, the rigidity of the curved reinforcing portion 3 having a closed cross-sectional shape can prevent the top plate portion 2 from being deformed out of the plane. Further, high rigidity can be exhibited even with respect to a compressive load and a tensile load along the extending direction of the curved edge 2a.
[0048]
Subsequently, before explaining the manufacturing method and the manufacturing apparatus of the present embodiment, a comparative example will be described first with reference to FIGS. 2 to 11.
In this comparative example, the manufacturing of the structural member 1 shown in FIG. 1 is attempted by the first to third steps described below. First, the first step will be described with reference to FIGS. 2 to 5.
[0049]
[Comparative example / First step]
FIG. 2 is a perspective view of each mold and blank 100 used in the first step of this comparative example. As shown in FIG. 2, in the structural member manufacturing apparatus in this comparative example, the die 10A on which the blank 100 is placed and the holder 20A that presses the portion of the blank 100 that becomes the top plate portion 2 from above. A punch 30A that forms a concave groove in a portion of the blank 100 that becomes the curved reinforcing portion 3 and a drive portion (not shown) that independently drives each of the holder 20A and the punch 30A are provided. ..
[0050]
The die 10A has a top plate support surface 11A that supports a portion of the blank 100 that becomes the top plate portion 2, a mold groove 12A that is connected to the top plate support surface 11A, and a horizontal plane 13A that is connected to the mold groove 12A. And have. The top plate support surface 11A is a horizontal plane including an edge 11Aa curved in the same direction as the curved edge 2a with the same radius of curvature.
[0051]
The mold groove 12A is connected to the top plate support surface 11A at the edge 11Aa and has the shape shown in FIG. Note that FIG. 3 is a view showing the shape of the mold groove 12A, in which (a) is a view taken along the line AA of (b), and (b) is a side surface seen from a direction orthogonal to the longitudinal direction. It is a figure. In FIGS. 3A and 3B, the edge is shown by a thick line in order to clarify the positional relationship of the edge in both figures. Similarly, in each of the following figures, a thick line may be used to indicate the positional relationship.
As shown in FIG. 3, the mold groove 12A is connected to the edge 11Aa and vertically downward to the mold groove side surface 12Aa, and is connected to the mold groove side surface 12Aa and is horizontally separated from the top plate support surface 11A. It is provided with a mold groove bottom surface 12Ab to face, and a mold groove side surface 12Ac connected to the mold groove bottom surface 12Ab and facing vertically upward.
[0052]
The mold groove side surface 12Aa and the mold groove side surface 12Ac have the same height dimension in the vertical direction at each position from one end to the other end along the extending direction. The mold groove side surface 12Aa and the mold groove side surface 12Ac have a concave curved shape that is curved in the same direction as the edge 11Aa in a plan view.
The horizontal width dimension of the mold groove bottom surface 12Ab is the same at each position from one end to the other end along the extending direction. The mold groove bottom surface 12Ab has a concave curved shape that is curved in the same direction as the edge 11Aa in a plan view. Further, as shown in FIG. 3B, the mold groove bottom surface 12Ab forms a horizontal surface without unevenness from one end to the other end of the mold groove 12A.
[0053]
Returning to FIG. 2, the holder 20A has a concave curved edge 20Aa having the same radius of curvature in the same direction as the edge 11Aa, and a flat lower surface 20Ab that presses the upper surface 100a of the blank 100.
The punch 30A has a pressure surface 30Aa having substantially the same shape as the mold groove 12A. The pressure surface 30Aa has a shape that is one size smaller than the shape of the mold groove 12A in consideration of the plate thickness of the blank 100. The lowermost surface of the pressurized surface 30Aa forms a horizontal surface without unevenness from one end to the other end.
The drive unit includes a drive mechanism that approaches and separates the holder 20A toward the die 10A, and another drive mechanism that approaches and separates the punch 30A toward the mold groove 12A. Therefore, it is possible to drive the holder 20A and the punch 30A individually.
[0054]
In order to carry out the first step by the structural member manufacturing apparatus having the above-described configuration, first, the blank 100 is placed on the top plate support surface 11A of the die 10A, and then the holder 20A is lowered to lower the blank 100. It is sandwiched between the die 10A and the die 10A. At that time, the end portion of the blank 100 is arranged so as to reach the horizontal plane 13A of the die 10A and then fixed.
Subsequently, by lowering the punch 30A by the drive mechanism, the end portion of the blank 100 is sandwiched between the die groove 12A of the die 10A and the pressure surface 30Aa to be plastically deformed. After that, the punch 30A is raised by the drive mechanism and the holder 20A is raised, so that the blank 100 after the first step is taken out from the die 10A.
[0055]
The blank 100 press-processed in this way is shown in FIGS. 4 and 5. In FIG. 4, (a) is a perspective view, and (b) is a view taken along the line BB of (a). FIG. 5 is a view taken along the line CC of FIG. 4 (a). After the first step, the top plate portion 2 and the inner wall 3a connected to the top plate portion 2 via the curved edge 2a are integrally formed. Of the blank 100, the upper surface and the lower surface of the concave band-shaped arc wall portion 100b pressurized by the lower end surface of the pressure surface 30Aa form a horizontal plane from one end to the other end in the extending direction. The band-shaped arc wall portion 100b is a portion to be a bottom wall 3b, an outer wall 3c, and an upper wall 3d through the subsequent second and third steps.
Further, the blank 100 is also formed with a vertical wall portion 100c that is connected to the strip-shaped arc wall portion 100b and rises upward. The vertical wall portion 100c is sandwiched between the pressure surface 30Aa and the mold groove 12A and plastically deforms into a concave curved shape, but the extension flange deformation at the upper end edge thereof is insufficient, so as shown in FIG. , It recedes diagonally so as to move away from the curved edge 2a.
[0056]
[Comparative example / Second step]
Subsequently, the second step of the comparative example will be described with reference to FIGS. 6A and 7. FIG. 6A is a perspective view of each mold used in the second step. 7A and 7B are views showing a blank after the second step, where FIG. 7A is a perspective view and FIG. 7B is a view taken along the line DD of FIG. 7A.
The structural member manufacturing apparatus of this comparative example further includes the mold shown in FIG. 6 (a). These molds include a die 40A on which the blank 100 after the first step is placed, and a holder 50A that presses the portion of the blank 100 that becomes the top plate portion 2 and the portion that becomes the bottom wall 3b from above. A drive mechanism that brings the punch 60A forming the outer wall 3c by partially pushing up and bending the strip-shaped arc wall portion 100b and the holder 50A close to and separated from the die 40A (not shown).(Shown) and another drive mechanism (not shown) that causes the punch 60A to approach and separate from the blank 100.
[0057]
The die 40A has a top plate support surface 41A that supports a portion of the blank 100 that becomes the top plate portion 2, and a mold groove (second mold groove) m1 that is connected to the top plate support surface 41A. is doing. The mold groove m1 is connected to the top plate support surface 41A and is formed vertically downward on the mold groove side surface 42A, and is connected to the mold groove side surface 42A and is directed in a direction horizontally separated from the top plate support surface 41A. It has a mold groove bottom surface 43A and.
The height dimension of the mold groove side surface 42A in the vertical direction is the same at each position from one end to the other end along the extending direction. The mold groove side surface 42A has a concave curved shape having the same radius of curvature in the same direction as the edge 11Aa in a plan view.
The horizontal width dimension of the mold groove bottom surface 43A is the same at each position from one end to the other end along the extending direction. The mold groove bottom surface 43A has a concave curved shape that is curved in the same direction as the edge 11Aa in a plan view. Further, the mold groove bottom surface 43A forms a horizontal surface without unevenness from one end to the other end.
[0058]
The holder 50A has a concave curved edge 50Aa having the same radius of curvature in the same direction as the edge 11Aa, a flat lower surface 50Ab that presses the upper surface 100a of the blank 100, and an inner surface that is connected to the lower surface 50Ab via the edge 50Aa. It is provided with a wall surface 50Ac, a lower surface 50Ad connected to the inner wall surface 50Ac, and a vertical wall surface 50Ae connected to the lower surface 50Ad and rising vertically upward.
[0059]
The inner wall surface 50Ac and the vertical wall surface 50Ae are parallel to each other and have a concave curved shape curved in the same direction as the edge 50Aa.
Further, the lower surface 50Ad has a concave curved shape that is curved in the same direction as the edge 11Aa when viewed from the bottom surface. The width dimension corresponds to the width dimension of the bottom wall 3b of the structural member 1. That is, the lower surface 50Ad has a narrower width than the strip-shaped arc wall portion 100b so as to pressurize only the portion of the strip-shaped arc wall portion 100b shown in FIG. 4, which is the bottom wall 3b. Therefore, the portion of the strip-shaped arc wall portion 100b that is not pressurized by the lower surface 50Ad bends vertically upward to become the outer wall 3c when the punch 60A is pushed up. More specifically, the strip-shaped arc wall portion 100b bends in a state where the ridge line 50Ad1 of the lower surface 50Ad shown in FIG. 6A hits the center of the strip-shaped arc wall portion 100b in the width direction. Therefore, the bottom wall 3b and the vertical wall portion 100c including the portion to be the outer wall 3c in the next step are formed with this bending position as a boundary.
[0060]
The punch 60A has a convex curved ridge line 60Aa that is curved in the same direction as the ridge line 50Ad1 of the holder 50A in a plan view. Then, when the punch 60A is raised, the ridge line 60Aa hits the back surface side of the strip-shaped arc wall portion 100b and bends in cooperation with the ridge line 50Ad1.
[0061]
In order to perform the second step using each of the molds described above, first, the blank 100 after the first step is placed on the top plate support surface 41A of the die 40A, and then the holder 50A is lowered to make the blank 100. Is pressed so as to be sandwiched between the die 40A and the die 40A. As a result, the inner wall 3a of the blank 100 is sandwiched and fixed between the mold groove side surface 42A and the inner wall surface 50Ac. Further, a part of the strip-shaped arc wall portion 100b of the blank 100 is sandwiched and fixed between the mold groove bottom surface 43A and the bottom surface 50Ad, leaving the other portion.
Subsequently, by raising the punch 60A by the drive mechanism, the other portion of the strip-shaped arc wall portion 100b is pushed up from below the bottom. As a result, a crease is formed between the portion of the strip-shaped arc wall portion 100b that becomes the bottom wall 3b and the portion that becomes the vertical wall portion 100c.
[0062]
FIG. 7 shows the blank 100 press-processed in the second step in this way. After the second step, the top plate portion 2, the inner wall 3a integrally formed via the curved edge 2a, the bottom wall 3b connected to the inner wall 3a, and the vertical wall portion 100c connected to the bottom wall 3b are formed. It is formed. The vertical wall portion 100c is bent in a part of the strip-shaped arc wall portion 100b, so that the height dimension in the vertical direction is extended as can be seen in comparison with FIG. 4B. In addition, the state of being retracted due to insufficient deformation of the stretch flange at the upper end edge of the vertical wall portion 100c during the first step remains after the second step.
[0063]
[Comparative example / Third step]
Subsequently, the third step of this comparative example will be described below with reference to FIGS. 8 to 10.
FIG. 8 is a perspective view of each mold used in the third step. 9 is a diagram showing the shape of the blank 100 before starting the third step, and is a view taken along the line EE of FIG. 7A. 10A and 10B are views showing a blank in the third step, where FIG. 10A is a perspective view and FIG. 10B is an arrow view of FF of FIG. 10A.
[0064]
The structural member manufacturing apparatus of this comparative example further includes the mold shown in FIG. These molds include the die 40A on which the blank 100 after the second step is continuously placed, the holder 70A arranged above the die 40A and moving up and down, and the punch 80A arranged adjacent to the die 40A and moving up and down. A pad 90A arranged on the punch 80A and moving up and down, a drive mechanism (not shown) that causes the holder 70A to approach and separate from the die 40A, and another drive mechanism that causes the punch 80A to approach and separate from the blank 100. (Not shown) and another drive mechanism (not shown) that causes the pad 90A to approach and separate from the punch 80A.
[0065]
The holder 70A is continuous with a concave curved ridge line 70Aa bent in the same direction as the edge 11Aa in a plan view, a flat lower surface 70Ab that presses the upper surface 100a of the blank 100, and a ridge line 70Aa with respect to the lower surface 70Ab. It is equipped with a vertical wall surface 70Ac that rises vertically upward.
The punch 80A has a convex curved edge 80Aa bent in the same direction as the ridge line 70Aa of the holder 70A in a plan view, and has a mold groove (third mold groove) m2 adjacent to the die 40A and an edge 80Aa. It has a flat upper surface 80Ab connected to the above. When the punch 80A is raised, the edge 80Aa hits the lower end portion of the vertical wall portion 100c of the blank 100 and gives a bend here.
The pad 90A has a flat lower surface 90Aa, a convex curved inclined surface 90Ab connected to the lower surface 90Aa, and a convex curved lower surface 90Ac connected to the inclined surface 90Ab. A step is formed between the lower surface 90Aa and the lower surface 90Ac via the inclined surface 90Ab. Further, the edge 90Ac1 of the lower surface 90Ac has a convex curved shape having the same radius of curvature in the same direction as the ridge line 70Aa.
[0066]
In order to perform the third step using each of the molds described above, first, the holder 70A is replaced with the holder 50A while the blank 100 after the second step is placed on the top plate support surface 41A of the die 40A. The top plate portion 2 is sandwiched between the top plate portion 2 and the top plate support surface 41A.
[0067]
Subsequently, in FIG. 9, the punch 80A is raised in the direction of the arrow UP to support the bottom wall 3b of the blank 100 and the portion of the vertical wall portion 100c that becomes the outer wall 3c from the outer periphery thereof.
After that, in FIG. 9, the pad 90A is lowered in the direction of the arrow DW, and the lower surface 90Aa of the pad 90A is brought into contact with the upper surface 80Ab of the punch 80A. At this time, if all the upper end edges of the vertical wall portion 100c of the blank 100 are located below the inclined surface 90Ab or the lower surface 90Ac, the vertical wall portion 100c can be bent toward the top plate portion 2. However, in this comparative example, after the first step and the second step, the vertical wall portion 100c remained inclined in the direction of retreating from the top plate portion 2, so that when the pad 90A was lowered in the third step, the lower surface thereof was lowered. The upper end edge of the vertical wall portion 100c abuts on 90Aa. Then, under the pressure of the pad 90A that is pushed down, the vertical wall portion 100c falls in the direction opposite to the original direction, and is finally sandwiched between the lower surface 90Aa and the upper surface 80Ab and crushed.
As a result, as shown in FIG. 10, since the curved reinforcing portion 3 having a closed cross-sectional shape is not formed on the side of the top plate portion 2, the component shape shown in FIG. 1 cannot be obtained.
[0068]
Of the above-described steps, FIG. 11 shows a perspective view in which the shape changes of the blank 100 from the second step to the third step are arranged in chronological order in the order of (a) to (f). In FIG. 11, (a) to (c) show the second step, and (d) to (f) show the third step.
First, in FIG. 11A, the blank 100 after the first step is sandwiched between the die 40A and the holder 50A. Then, by raising the punch 60A, the state shown in FIG. 11B is obtained. At this time, the upper end edge of the vertical wall portion 100c extends along the extending direction and tries to deform the flange, but a sufficient amount of deformation cannot be obtained. Therefore, the vertical wall portion 100c cannot collapse in the direction indicated by the arrow a. As a result, even if the punch 60A is further raised, it is difficult for the vertical wall portion 100c to have a crease at the boundary between the portion that becomes the outer wall 3c and the portion that becomes the upper wall 3d, so that the upper end edge of the vertical wall portion 100c is the top plate portion. It remains away from 2.
In the subsequent third step, in order to push down the upper end edge of the vertical wall portion 100c by the pad 90A in a state where the vertical wall portion 100c of the blank 100 is not sufficiently collapsed, as shown in FIGS. 11 (d) to 11 (e). The vertical wall portion 100c collapses in the direction opposite to the original direction, and is crushed as shown in (f).
[0069]
As described above, it is not easy to form the curved reinforcing portion 3 along the curved edge 2a with respect to the flat plate-shaped blank 100 having the curved edge 2a, and the results of diligent studies by the present inventors on the reason. , It was found that the cause was insufficient elongation flange deformation in FIG. 11B in the second step. The first embodiment which improved this point will be described below with reference to FIGS. 12 to 20.
[0070]
[First Embodiment / First Step]
FIG. 12 is a perspective view of each mold and blank 100 used in the first step of the present embodiment. As shown in FIG. 12, in the structural member manufacturing apparatus of the present embodiment, the die 110 on which the blank 100 is placed and the holder 120 that presses the portion of the blank 100 that becomes the top plate portion 2 from above. A punch 130 that forms a concave groove in a portion of the blank 100 that forms the curved reinforcing portion 3, and a drive portion (not shown) that independently drives each of the holder 120 and the punch 130. There is.
[0071]
The die 110 has a top plate support surface 111 that supports a portion of the blank 100 that becomes the top plate portion 2, a mold groove 112 that is connected to the top plate support surface 111, and a horizontal plane 113 that is connected to the mold groove 112. And have. The top plate support surface 111 is a horizontal plane having an edge 111a curved in the same direction as the curved edge 2a and having the same radius of curvature.
[0072]
The mold groove 112 is connected to the top plate support surface 111 at the edge 111a and has the shape shown in FIG. Note that FIG. 13 is a view showing the shape of the mold groove 112, in which (a) is a view taken along the line GG of (b), and (b) is a side surface seen from a direction orthogonal to the longitudinal direction. It is a figure. In FIGS. 13A and 13B, the edge is shown by a thick line in order to clarify the positional relationship of the edge in both figures. Similarly, in each of the following figures, a thick line may be used to indicate the positional relationship.
As shown in FIG. 13, the mold groove 112 is connected to the edge 111a and vertically downward to the mold groove side surface 112a, and is connected to the mold groove side surface 112a and is horizontally separated from the top plate support surface 111. It is provided with a mold groove bottom surface 112b toward which the mold groove is directed, and a mold groove side surface 112c which is connected to the mold groove bottom surface 112b and is directed vertically upward.
[0073]
The height dimension of the mold groove side surface 112a and the mold groove side surface 112c in the vertical direction is different between the central position and the both end positions along the extending direction thereof. That is, when viewed from the side, the upper end edges of the mold groove side surface 112a and the mold groove side surface 112c have a linear shape, while the lower end edge is a curved line that is convex vertically upward.It has a shape. It is preferable that the radius of curvature R1 of the curved line shape is larger than the radius of curvature R of the curved edge 2a in the structural member 1 shown in FIG. The reason will be described later.
[0074]
The height dimension in the vertical direction of the mold groove side surface 112a and the mold groove side surface 112c having the lower end edges of the arch shape, respectively, is longer at both ends than at the center position in the extending direction. There is.
The mold groove side surface 112a and the mold groove side surface 112c have a curved shape curved in the same direction as the edge 111a in a plan view. Further, the radius of curvature when the mold groove side surface 112a is viewed in a plan view is equal to the radius of curvature R of the curved edge 2a in the structural member 1. Further, the radius of curvature when the mold groove side surface 112c is viewed in a plan view is larger than the radius of curvature of the mold groove side surface 112a. This difference in radius of curvature absorbs the height dimensional difference along the extending direction of each of the mold groove side surface 112a and the mold groove side surface 112c. In other words, the sum of the perimeters, which is the sum of the lengths l1, l2, and l3 shown in FIG. 13A, is the same at each position in the extending direction of the mold groove 112. This makes it possible to align the size of the cross-sectional shape of the curved reinforcing portion 3 after molding at each position in the extending direction.
[0075]
The mold groove bottom surface 112b has a concave curved shape that is curved in the same direction as the edge 111a in a plan view. Further, as shown in FIG. 13B, the mold groove bottom surface 112b has a height difference h in a vertical cross-sectional view between the center position and the end position along the extending direction thereof. That is, the mold groove bottom surface 112b has a convex curved shape that is bent so that both end positions are relatively low with respect to the center position along the extending direction thereof.
[0076]
Returning to FIG. 12, the holder 120 has a concave curved edge 120a having the same radius of curvature in the same direction as the edge 111a, and a flat lower surface 120b that presses the upper surface 100a of the blank 100.
[0077]
The punch 130 has a pressure surface 130a having substantially the same shape as the mold groove 112. The pressure surface 130a is one size smaller than the shape of the mold groove 112 in consideration of the plate thickness of the blank 100.
The pressure surface 130a has a pair of punch outer surfaces 130a1 and 130a2, and a punch lower end surface 130a3 connecting the lower end edges thereof. The punch outer surfaces 130a1, 130a2 and the punch lower end surfaces 130a3 have a curved shape curved in the same direction as the edge 111a in a plan view.
[0078]
The height dimensions of the punch outer surfaces 130a1 and 130a2 in the vertical direction are different between the center position and the both end positions along the extending direction thereof. That is, when viewed from the side, the upper end edges of the punch outer surfaces 130a1 and 130a2 have a linear shape, while the lower end edges have a convex curved line shape vertically upward.
The punch outer surfaces 130a1 and 130a2 having such arch-shaped lower end edges have a height dimension in the vertical direction longer at both ends than at the center position in the extension direction.
These punch outer surfaces 130a1 and 130a2 have a concave curved shape curved in the same direction as the edge 111a in a plan view. Further, the radius of curvature when the punch outer surface 130a1 is viewed in a plan view is equal to the radius of curvature R of the curved edge 2a in the structural member 1. Further, the radius of curvature when the punch outer surface 130a2 is viewed in a plan view is larger than the radius of curvature of the punch outer surface 130a1. Due to this difference in radius of curvature, the difference in height and dimension along the extending direction of each of the punch outer surfaces 130a1 and 130a2 is absorbed. In other words, the sum of the perimeters, which is the sum of the lengths l4, l5, and l6 shown in FIG. 12, is the same at each position in the extending direction of the punch 130.
[0079]
The drive unit includes a drive mechanism that approaches and separates the holder 120 toward the die 110, and another drive mechanism that approaches and separates the punch 130 toward the mold groove 112. Therefore, it is possible to drive the holder 120 and the punch 130 individually.
Blank 100 is a flat plate material having a substantially rectangular shape. The plate thickness is exemplified by 0.8 mm to 6.0 mm, but is not limited to this thickness. As the material of the blank 100, a metal material such as steel, an aluminum alloy or a magnesium alloy, or a resin material such as glass fiber or carbon fiber can be used. Further, a composite material of a metal material and a resin material may be used as the material of the blank 100.
[0080] [0080]
In order to perform the first step by the structural member manufacturing apparatus having the above-described configuration, first, the blank 100 is placed on the top plate support surface 111 of the die 110, and then the holder 120 is lowered to lower the blank 100. It is sandwiched between the die 110 and the die 110. At that time, the end portion of the blank 100 is arranged so as to overlap the horizontal plane 113 of the die 110 and then fixed.
Subsequently, by lowering the punch 130 by the drive mechanism, the blank 100 is sandwiched between the die groove 112 of the die 110 and the pressure surface 130a and plastically deformed. After that, the punch 130 is raised by the drive mechanism, and then the holder 120 is raised. Then, the blank 100 after the first step is taken out from the die 110.
[0081]
The blank 100 press-processed in this way is shown in FIGS. 14 and 15. In FIG. 14, (a) is a perspective view, and (b) is an arrow view of (a). 15 is a view taken along the line I-I in FIG. 14 (a). After the first step, the top plate portion 2 and the inner wall 3a connected to the top plate portion 2 via the curved edge 2a are integrally formed.
The blank 100 after the first step has a groove portion m including an inner wall 3a and a vertical wall portion 100c, and a strip-shaped arc wall portion 100b connecting the lower end edges thereof. The inner wall 3a, the vertical wall portion 100c, and the strip-shaped arc wall portion 100b have a curved shape curved in the same direction in a plan view.
[0082]
The inner wall 3a and the vertical wall portion 100c are provided with a difference in the height dimension of the lower end edge between the central position and the both end positions along the extending direction thereof. That is, each lower end edge of the inner wall 3a and the vertical wall portion 100c has a curved line shape that is convex vertically upward in a side view.
When viewed in a plan view, the radius of curvature of the vertical wall portion 100c is larger than the radius of curvature of the inner wall 3a. Due to this difference in radius of curvature, the difference in height and dimension along the extending direction of the inner wall 3a and the vertical wall portion 100c is absorbed. In other words, the sum of the perimeters, which is the sum of the lengths l7, l8, and l9 shown in FIG. 15, is the same at each position in the extending direction of the strip-shaped arc wall portion 100b.
[0083]
The band-shaped arc wall portion 100b has a curved shape curved in the same direction as the edge 111a in a plan view. Further, the strip-shaped arc wall portion 100b has a height difference between the center position and the end position along the extending direction thereof in a vertical cross-sectional view. That is, the strip-shaped arc wall portion 100b has a convex curved shape that is bent so that both end positions are relatively lower than the central position along the extending direction thereof. The radius of curvature of the band-shaped arc wall portion 100b in the vertical cross-sectional view is larger than the radius of curvature of the center line CL passing through the center position in the width direction in the plan view of the band-shaped arc wall portion 100b. As a result, when the blank 100 is placed by changing the mold in the next step, it is possible to prevent the blank 100 from becoming too high and unstable.
[0084]
The band-shaped arc wall portion 100b is a portion that becomes a bottom wall 3b and an outer wall 3c through the subsequent second and third steps. As described above, in the first step (intermediate step), the central position (intermediate position) in the vertical cross-sectional view along the extending direction of the groove portion m on the band-shaped arc wall portion (bottom wall) 100b of the groove portion m by pressing. And, a height difference is provided between both ends (both adjacent positions) sandwiching this central position. As a result, a curved portion (first curved portion) having a concave curved shape in a plan view and a convex curved shape in a vertical cross-sectional view is formed on the band-shaped arc wall portion 100b. In the present embodiment, all of the strip-shaped arc wall portion 100b is a curved portion, but the present invention is not limited to this embodiment, and only a part of the strip-shaped arc wall portion 100b may be a curved portion.
[0085]
Further, the blank 100 is also formed with a vertical wall portion 100c that is connected to the strip-shaped arc wall portion 100b and rises upward. In the above-mentioned comparative example, as described with reference to FIG. 5, since the extension flange deformation at the upper end edge of the vertical wall portion 100c was insufficient, the vertical wall portion 100c was slanted backward so as to be away from the curved edge 2a. On the other hand, in the present embodiment, since the strip-shaped arc wall portion 100b is bent so as to form a convex curved shape vertically upward in the first step, the extension flange deformation at the upper end edge of the vertical wall portion 100c is performed. Can be given before the second step. That is, the vertical wall portion 100c is bent and deformed in the in-plane direction so that the upper end edge is wider than the lower end edge of the vertical wall portion 100c. As a result, in FIG. 15 of the present embodiment, the vertical wall portion 100c can be brought closer to the curved edge 2a in advance as compared with FIG. 5 of the comparative example.
[0086]
[First Embodiment / Second Step]
Subsequently, the second step of this embodiment will be described with reference to FIGS. 6 and 16. 16A and 16B are views showing a blank after the second step, in which FIG. 16A is a perspective view and FIG. 16B is a JJ arrow view of FIG. 16A. Since the same molds as those shown in FIG. 6A are used in this step, the description of these molds will be omitted.
[0087]
In order to perform the second step using the die 40A, the holder 50A, and the punch 60A shown in FIG. 6A, first, the blank 100 after the first step is placed on the top plate support surface 41A of the die 40A. do. At that time, the bottom wall 3b is arranged on the bottom surface 43A of the mold groove, and the inner wall 3a is arranged so as to be in surface contact with the side surface 42A of the mold groove. At this time, since the bottom wall 3b has a curved shape, it slightly floats from the mold groove bottom surface 43A except for both ends thereof.
[0088]
Subsequently, when the holder 50A is lowered, the flat lower surface 50Ad abuts on the top of the convex curved bottom wall 3b at the center position in the extending direction. By further lowering the holder 50A, the bottom wall 3b is bent back so as to be gradually reduced in curvature. Then, when the holder 50A reaches the bottom dead center, the bottom wall 3b is sandwiched between the lower surface 50Ad and the mold groove bottom surface 43A and plastically deformed into a completely flat shape. In this process, the force for bending back the curvature of the bottom wall 3b is transmitted to the vertical wall portion 100c, so that the vertical wall portion 100c is plastically deformed so as to stand up more than in the original state.
As described above, the inner wall 3a of the blank 100 is sandwiched and fixed between the mold groove side surface 42A and the inner wall surface 50Ac. Further, a part of the strip-shaped arc wall portion 100b of the blank 100 is sandwiched and fixed between the mold groove bottom surface 43A and the bottom surface 50Ad, leaving the other portion.
[0089]
Subsequently, by raising the punch 60A by the drive mechanism, the other portion of the strip-shaped arc wall portion 100b is pushed up from below the bottom. As a result, a crease is formed between the portion of the strip-shaped arc wall portion 100b that becomes the bottom wall 3b and the portion that becomes the vertical wall portion 100c.
At this time, in order for the vertical wall portion 100c to incline toward the curved edge 2a, it is necessary to deform the extension flange along the extending direction of the upper end edge of the vertical wall portion 100c. In the comparative example, the extension flange deformation was insufficient, so that the upper end edge of the vertical wall portion 100c could not be inclined. On the other hand, in the present embodiment, since the extension flange deformation is given in advance at the stage of the first step, the upper end edge of the vertical wall portion 100c is curved at the curved edge 2a while leaving a bend at an intermediate position in the height direction of the vertical wall portion 100c. It can be fully collapsed toward.
[0090]
As shown in FIG. 6B, it is preferable that the vertical wall surface 60Ae of the punch 60A is arranged horizontally with a distance cl of 5 mm or more and 50 mm or less with respect to the vertical wall surface 50Ae of the holder 50A. In this case, while leaving the bent portion bp formed in the first step at an intermediate position in the height direction of the vertical wall portion 100c, the upper end edge of the vertical wall portion 100c is tilted toward the top plate portion 2 so as to approach the front bend.Can be done more reliably. On the other hand, if the distance cl is smaller than 5 mm, the space between the vertical wall surface 50Ae and the vertical wall surface 60Ae is too narrow, so that the bent portion bp is crushed and the vertical wall portion 100c may not be properly bent in the next step. Further, when the distance cl is larger than 50 mm, the bent portion bp remains, but the upper end edge of the vertical wall portion 100c remains retracted so as to move away from the top plate portion 2, so that the vertical wall portion 100c is bent in the next step. There is a risk that it cannot be bent at the partial bp.
For the above reasons, in a plan view, the vertical wall surface 60Ae (second vertical wall surface) is separated from the vertical wall surface 50Ae (first vertical wall surface) of the holder 50A (first holder) by a distance cl of 5 mm or more and 50 mm or less in the horizontal direction. It is preferable to arrange the punch 60A (second punch) so that the wall surface) is arranged so as to face each other.
[0091]
FIG. 16 shows the blank 100 press-processed in the second step in this way. After the second step, the top plate portion 2, the inner wall 3a integrally formed via the curved edge 2a, the flat bottom wall 3b connected to the inner wall 3a, and the vertical wall portion 100c connected to the bottom wall 3b. And are formed. The vertical wall portion 100c has an elongated dimension in the vertical direction as can be seen in comparison with FIG. 14 (b) by bending a part of the strip-shaped arc wall portion 100b. Further, the bend between the strip-shaped arc wall portion 100b and the vertical wall portion 100c provided in the first step remains at the position indicated by the reference numeral P in FIG. 16 (b) in the vertical wall portion 100c after the second step. There is. Therefore, the upper end edge of the vertical wall portion 100c is closer to the curved edge 2a than in the case of the second step of the comparative example.
[0092]
[First Embodiment / Third Step]
Subsequently, the third step of the present embodiment will be described with reference to FIGS. 8, 17, and 18. FIG. 17 is a diagram showing the shape of the blank 100 before starting the third step, and is a view taken along the line KK of FIG. 16 (a). 18A and 18B are views showing a blank after the third step, in which FIG. 18A is a perspective view and FIG. 18B is an arrow view of LL of FIG. 18A. Since the same molds as those shown in FIG. 8 are used in this step, their description will be omitted.
[0093]
In order to perform the third step using the die 40A, the holder 70A, the punch 80A, and the pad 90A shown in FIG. 8, first, the blank 100 after the second step is placed on the top plate support surface 41A of the die 40A. The top plate portion 2 is sandwiched between the top plate portion 2 and the top plate support surface 41A by using the holder 70A instead of the holder 50A. At this time, the holder 70A is arranged so that the vertical wall surface 70Ac is recessed from the edge 41Aa of the die 40A by a predetermined width dimension t. As a result, the region indicated by the hatching of the width dimension t in FIG. 8 serves as a joining allowance in the horizontal direction when the vertical wall portion 100c is bent to form a closed cross section in the third step.
[0094]
Subsequently, in FIG. 17, the punch 80A is raised in the direction of the arrow UP to support the bottom wall 3b of the blank 100 and the portion of the vertical wall portion 100c that becomes the outer wall 3c from the outer periphery thereof.
After that, in FIG. 17, the pad 90A is lowered in the direction of the arrow DW, and the lower surface 90Aa of the pad 90A is brought into contact with the upper surface 80Ab of the punch 80A. At this time, all the upper end edges of the vertical wall portion 100c of the blank 100 are below the inclined surface 90Ab or the lower surface 90Ac. Therefore, when the pad 90A is lowered, the upper end edge of the vertical wall portion 100c can be pushed down while being guided toward the joint position on the top plate portion 2 by the inclined surface 90Ab and the lower surface 90Ac. At that time, the bend (the bend portion bp) indicated by the reference numeral P of the vertical wall portion 100c gradually increases, and as a result, a boundary between the outer wall 3c and the upper wall 3d is formed.
[0095]
Moreover, even if the upper end edge of the vertical wall portion 100c tries to exceed the joint position with the top plate portion 2 before the pad 90A reaches the bottom dead center, the movement is stopped by the vertical wall surface 70Ac. The vertical wall portion 100c having the upper end edge dammed up comes into close contact with the inner wall surface of the closed space formed by the die 40A, the punch 80A, and the pad 90A because the force applied to the vertical wall surface 70Ac returns to itself as a reaction force. The closed cross-sectional shape is formed in this way.
[0096]
Here, the gap at the bottom dead center of molding with respect to the top plate support surface 41A (first top plate support surface) of the die 40A is larger on the pressure surface of the pad 90A than on the pressure surface of the holder 70A. More specifically, when the holder 70A reaches the bottom dead center, the gap between the pressurized surface of the holder 70A and the top plate supporting surface 41A of the die 40A is defined as g1. Further, when the pad 90A reaches the bottom dead center, the gap between the pressure surface of the pad 90A and the top plate support surface 41A of the die 40A is set to g2. In this case, the gap g1 is substantially equal to the plate thickness of the top plate portion 2, and the gap g2 is substantially equal to the dimension of the plate thickness of the top plate portion 2 plus the plate thickness of the upper end edge of the vertical wall portion 100c. That is, the gap g2> the gap g1. Therefore, in the holder 70A, the top plate portion 2 is firmly sandwiched between the die 40A, and in the pad 90A, the top plate portion 2 and the upper end edge of the vertical wall portion 100c are sandwiched between the die 40A. You can get the joining allowance of.
[0097]
Finally, the curved reinforcing portion 3 shown in FIG. 18 is formed by joining the upper wall 3d to the joining position of the top plate portion 2 by using an appropriate joining means. The curved reinforcing portion 3 has a uniform cross-sectional shape at each position along the extending direction thereof.
[0098]
In this step, the vertical wall surface 70Ac regulates the excessive movement of the upper end edge of the vertical wall portion 100c, but the present invention is not limited to this form, and is not limited to this form. , A regulation surface 90Ad that is connected to the lower surface 90Ac and is formed downward from the end of the lower surface 90Ac may be provided. In this case, since the movement of the upper end edge of the vertical wall portion 100c is dammed by the regulation surface 90Ad, the vertical wall surface 70Ac can be omitted from the holder 70A.
Further, in this step, the third step was performed following the second step, but the present invention is not limited to this mode. For example, as shown in FIG. 17, after the second step and before the third step, the upper end edge bending step of bending the upper end edge of the vertical wall portion 100c toward the top plate portion 2 to form the bent portion Q is performed. You may also have more. In this case, it is possible to prevent the lower surface 90Ac of the pad 90A from being worn due to the sliding contact with the upper end edge of the vertical wall portion 100c. In addition, when the pad 90A reaches the bottom dead center, the lower surface 90Ac crushes the bent portion Q flatly, so that the bent portion Q is not left in the subsequent process.
Instead of providing the bent portion Q, a coating agent that imparts wear resistance may be applied in advance to the inclined surface 90Ab and the lower surface 90Ac of the pad 90A. Further, both the formation of the bent portion Q and the application of the coating agent may be adopted.
[0099]
Of the above-described steps, FIG. 20 shows a perspective view in which the shape changes of the blank 100 from the second step to the third step are arranged in chronological order in the order of (a) to (f). In FIG. 20, (a) to (c) show the second step, and (d) to (f) show the third step.
First, in FIG. 20A, the blank 100 after the first step is sandwiched between the die 40A and the holder 50A. Then, by raising the punch 60A, the state shown in FIG. 20B is obtained. At this time, in order to incline the upper end edge of the vertical wall portion 100c toward the top plate portion 2, it is necessary to deform the stretch flange along the extending direction thereof, but the stretch flange deformation has already been imparted in the first step. Because it is made, it can be tilted with a margin. Therefore, even if the punch 60A is further raised to the state shown in FIG. 20 (b), the crease at the boundary between the portion of the vertical wall portion 100c that becomes the outer wall 3c and the portion that becomes the upper wall 3d is maintained.
In the subsequent third step, in order to push down the upper end edge of the vertical wall portion 100c by the pad 90A in a state where the vertical wall portion 100c of the blank 100 is sufficiently collapsed, as shown in FIGS. The wall portion 100c properly collapses toward the joint position with the top plate portion 2. Then, as shown in FIG. 20 (f), the structural member 1 having the curved reinforcing portion 3 is completed by fixing the upper wall 3d at the joining position by using an appropriate joining means.
[0100]
The outline of this embodiment described above is summarized below.
In the method of manufacturing the structural member of the present embodiment, the top plate portion 2 having the curved edge 2a is integrally formed with the top plate portion 2 along the extending direction of the curved edge 2a, and the extending direction of the curved edge 2a. This is a method of manufacturing a structural member 1 having a curved reinforcing portion 3 having a closed cross-sectional shape having a cross section orthogonal to the blank (flat plate material) 100.
Then, in this manufacturing method, in the blank 100, another portion (inner wall 3a, strip-shaped) connected to the curved edge 2a of the top plate portion 2 while sandwiching the portion (first portion) corresponding to the top plate portion 2. The arc wall portion 100b, the vertical wall portion 100c, and the second portion) are pressed in the depth direction with respect to the surface of the blank 100, along the extending direction of the curved edge 2a and orthogonal to the extending direction. The first step (intermediate step) of forming a groove portion m having a U-shaped cross section and a vertical wall portion 100c connected to the groove portion m; It has a third step (joining step) of forming the portion 3 and;
Then, in the press of the first step, a height difference is provided between the center position and the end position of the band-shaped arc wall portion 100b (bottom wall) of the groove portion m viewed in vertical cross section along the extending direction. ..
That is, as shown in FIG. 14, the strip-shaped arc wall portion 100b is formed into a concave curved shape in a plan view and a convex curved shape in a vertical cross-sectional view by the press in the first step.
At the time of press molding in the first step, the portion corresponding to the top plate portion 2 is not completely fixed but is in a sandwiched state. Therefore, the movement and deformation of the pinched portion to the outside of the plane is restricted, but the metal flow in which a part of the pinched portion toward another portion such as the inner wall 3a is allowed.
[0101]
In the third step, the upper end edge of the vertical wall portion 100c is pushed down toward the groove portion m while allowing movement toward the top plate portion 2, so that the upper end edge is bent toward the top plate portion 2. Then, the movement of the upper end edge beyond the planned joining position in the top plate portion 2 is restricted.
Before the third step, there may be further an upper end edge bending step of bending the upper end edge toward the top plate portion 2 to form a bent portion Q.
[0102]
By the press in the first step, the sum of the perimeters, which is the sum of the cross-sectional line lengths of the U-shaped inner shape (the total lengths l7, l8, l9 shown in FIG. ), It is preferable that the ratio obtained by dividing the cross-sectional line length at the center position by the cross-section line length at the end position is in the range of 0.7 to 1.3. Further, it is more preferable that the cross-sectional line lengths are the same at the center position and the end position. Further, it is most preferable that the cross-sectional line lengths at each position in the extending direction of the groove portion m are all equal.
When the ratio of the cross-section line length is less than 0.7 or exceeds 1.3, the difference in the cross-section line length between the center position and the end position becomes too large. In this case, when a curved reinforcing portion having substantially the same cross-sectional area at each position along the extending direction of the groove portion m is formed, the difference in the cross-sectional line length is the molding of cracks and wrinkles at the edge of the upper wall 3d. May cause problems. Therefore, the ratio of the cross-sectional line lengths is preferably in the range of 0.7 to 1.3.
[0103]
Further, by pressing in the first step, the radius of curvature R (mm) of the center line passing through the center position in the width direction in the plan view of the strip-shaped arc wall portion 100b is set to the radius of curvature R1 (mm) in the vertical cross-sectional view of the strip-shaped arc wall portion 100b. The R / R1 ratio divided by) may be in the range of 0.2 to 1.2. In this case, even if a 780 MPa class high-strength steel plate is used as the blank 100, suitable molding results can be obtained without constriction or dimensional defects. Further, when a high-strength steel sheet of 980 MPa class or higher is used, it is more preferable that the R / R1 ratio is in the range of 0.3 to 0.9. In this case, even if a high-strength steel sheet of 980 MPa class is used. , Suitable molding results can be obtained without constriction or dimensional defects. Further, it is most preferable to set the R / R1 ratio to 0.5, and in this case, a high-strength steel plate of 1180 MPa class is used.However, suitable molding results can be obtained without constriction or dimensional defects.
On the other hand, when viewed from another viewpoint, the vertical section of the band-shaped arc wall portion 100b is more than the radius of curvature R of the center line CL passing through the center position in the width direction in the plan view of the band-shaped arc wall portion 100b due to the press in the first step. It is preferable that the radius of curvature R1 in the plane view is larger (R1> R). In this case, it is possible to avoid unstable positioning when the structural member is transferred to another mold in the next step.
The structural member 1 may be an automobile body part. More specifically, the present invention may be applied in the manufacture of the lower arm.
[0104]
The structural member manufacturing apparatus of the present embodiment is suitably used for the above manufacturing method, and the structural member 1 is manufactured from the blank 100.
Then, in this manufacturing apparatus, the die (first die) 110 in which the mold groove (first mold groove) 112 curved in a plan view is formed and the die (first die) 110 are relatively close to each other and separated from the mold groove 112. The punch (first punch) 130 to be used is used in the first step. The bottom surface (bottom surface) 112b of the mold groove 112 has a height difference in vertical cross-sectional view between the center position and the end position along the extending direction of the mold groove bottom surface 112b.
Further, the punch lower end surface 130a3 of the pressurizing surface 130a of the punch 130 has a height difference corresponding to the mold groove bottom surface 112b. The "corresponding height difference" in the punch lower end surface 130a3 means the height difference formed by bending the punch lower end surface 130a3 in the same direction as the mold groove bottom surface 112b, and means the height difference formed by bending the punch lower end surface 130a3 in the same direction as the mold groove bottom surface 112b. It is preferable that they are the same.
[0105]
The mold groove bottom surface 112b of the mold groove 112 has a concave curved shape in a plan view and a convex curved shape in a vertical cross-sectional view. That is, the mold groove bottom surface 112b has a center position (intermediate position) viewed in a vertical cross section along the extending direction of the mold groove (first mold groove) 112 and both end positions (next to each other) sandwiching the center position. It has a height difference from the position). The pressure surface 130a of the punch (first punch) 130 has a height difference corresponding to the bottom surface 112b of the die groove. Further, the mold groove bottom surface 112b forms a curved surface (first mold curved surface) having a concave curved shape in a plan view and a convex curved shape in a vertical cross-sectional view. In the present embodiment, the entire mold groove bottom surface 112b is a curved surface, but the present invention is not limited to this embodiment, and only a part of the mold groove bottom surface 112b may be a curved surface.
[0106]
When looking at the U-shaped cross-section line length, which is a cross section orthogonal to the extending direction of the mold groove 112, the ratio obtained by dividing the cross-section line length at the center position by the cross-section line length at the end position is 0. It is preferably in the range of 7. to 1.3. Further, it is more preferable that the cross-sectional line lengths are the same at the center position and the end position. Further, it is most preferable that the cross-sectional line lengths at each position of the mold groove 112 in the extending direction are all equal. In this case, molding defects can be prevented more reliably.
[0107]
The R / R1 ratio of the bottom surface 112b of the mold groove divided by the radius of curvature R (mm) of the center line passing through the center position in the width direction in the plan view with the radius of curvature R1 (mm) in the vertical cross-sectional view is 0.2 to It may be within the range of 1.2. In this case, even if a 780 MPa class high-strength steel plate is used as the blank 100, suitable molding results can be obtained without constriction or dimensional defects. Further, when a high-strength steel sheet of 980 MPa class or higher is used, it is more preferable that the R / R1 ratio is in the range of 0.3 to 0.9. In this case, even if a high-strength steel sheet of 980 MPa class is used. , Suitable molding results can be obtained without constriction or dimensional defects. Further, it is most preferable to set the R / R1 ratio to 0.5. In this case, even if a high-strength steel plate of 1180 MPa class is used, suitable molding results without constriction or dimensional defects can be obtained.
On the other hand, when viewed from another viewpoint, the radius of curvature R1 of the bottom surface 112b of the mold groove in the vertical cross-sectional view is larger than the radius of curvature R of the center line passing through the center position in the width direction in the plan view (R1>). R) is preferable. In this case, it is possible to avoid unstable positioning when the structural member is transferred to another mold in the next step.
[0108]
Further, the manufacturing apparatus further comprises the following molds used in the second step: a die (second die) 40A having a mold groove bottom surface (second mold groove) 43A thinner than the mold groove 112. And; a holder (first holder) 50A having a lower surface (curved convex portion) 50Ad having a shape corresponding to the mold groove bottom surface 43A; Punch (second punch) 60A that is relatively close and separated.
[0109]
Further, the manufacturing apparatus further comprises the following molds used in the third step: a holder (second holder) 70A arranged so as to overlap the die 40A; and a third mold adjacent to the mold groove bottom surface 43A. A punch (third punch) 80A having a die groove; and a pad 90A having a lower surface (pressurized surface) 90Ac approaching and separating from both the die groove bottom surface 43A and the third die groove.
The holder 70A has a vertical wall surface (first regulatory surface) 70Ac adjacent to and intersecting the lower surface 90Ac of the pad 90A. Alternatively, as shown in FIG. 19, the pad 90A may include a regulatory surface (second regulatory surface) 90Ad that is continuous with the lower surface 90Ac and intersects the lower surface 90Ac.
[0110]
[Second Embodiment]
In this embodiment, a manufacturing method and a manufacturing apparatus for molding the structural member 201 shown in FIG. 21 from a flat plate material will be described. 21 is a diagram showing the structural member 201 manufactured by the method for manufacturing the structural member according to the present embodiment, in which FIG. 21A is a perspective view and FIG. 21B is a plan view.
The structural member 201 shown in FIG. 21 is integrally formed with the top plate portion 202 having a convex curved edge 202a in a plan view and the top plate portion 202 along the extending direction of the curved edge 202a, and is extended. It has a curved reinforcing portion 203 whose cross section orthogonal to the direction has a closed cross-sectional shape. In addition, in FIG. 21A, in order to make the shapes of the curved edge 202a and the curved reinforcing portion 203 easy to understand, the joint portion is slightly opened and shown, but in reality, there is no gap at the joint portion. It is joined and the curved reinforcing portion 203 forms a closed cross-sectional shape. It may be illustrated in other drawings as well.
[0111]
The top plate portion 202 includes a pair of both side edges 202b and 202c parallel to each other, the curved edge 202a which is connected between the side edges 202b and 202c and forms a leading edge, and both side edges 202b which face the curved edge 202a. It is a flat plate partitioned by a trailing edge 202d extending between 202c and a trailing edge 202d. Of these, the both side edges 202b and 202c and the trailing edge 202d each have a linear shape. On the other hand, the curved edge 202a has a convex curved shape whose center is farther from the trailing edge 202d than both ends thereof. As the radius of curvature R1 in the plan view of this convex curved shape, 100 mm to 400 mm is exemplified. However, the radius of curvature R1 is not limited to this range.
[0112]
The curved reinforcing portion 203 is connected to the inner wall 203a which is connected to the curved edge 202a of the top plate portion 202 and goes vertically downward, the bottom wall 203b which is connected to the inner wall 203a and is directed to be horizontally separated from the top plate portion 202, and the bottom wall 203b. It is provided with an outer wall 203c that is connected and vertically upwards, and an upper wall 203d that is connected to the outer wall 203c and joined to the upper surface 202e of the top plate portion 202.
The height dimension of the inner wall 203a in the vertical direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 203. The inner wall 203a has a convex curved shape having the same radius of curvature in the same direction as the curved edge 202a in a plan sectional view.
The width dimension of the bottom wall 203b in the horizontal direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 203. The bottom wall 203b is parallel to the top plate portion 202 in the side view, and has a convex curved shape bent in the same direction as the curved edge 202a in the bottom view.
[0113]
The height dimension of the outer wall 203c in the vertical direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 203. The outer wall 203c has a convex curved shape that is curved in the same direction as the curved edge 202a in a plan sectional view.
The width dimension of the upper wall 203d in the horizontal direction is the same at each position from one end to the other end along the extending direction of the curved reinforcing portion 203, and is wider than the bottom wall 203b. The upper wall 203d is parallel to the top plate portion 202 in the vertical cross-sectional view, and has a convex curved shape curved in the same direction as the curved edge 202a in the plan view. The upper wall 203d is joined to the upper surface 202e of the top plate portion 202 at a position beyond the curved edge 202a toward the trailing edge 202d. As the joining means, for example, welding, adhesion, bolt fixing and the like can be appropriately used.
[0114]
The inner wall 203a and the outer wall 203c are parallel to each other, and the upper wall 203d and the bottom wall 203b are parallel to each other. A closed cross-sectional shape is formed by the four wall portions of the inner wall 203a, the bottom wall 203b, the outer wall 203c, and the upper wall 203d. That is, in the present embodiment, a convex curved space is formed in the curved reinforcing portion 203, and the space is provided only at one end and the other end along the extending direction of the curved reinforcing portion 203. Communicates with the outside.
According to the structural member 201 having the above-described configuration, the rigidity of the curved reinforcing portion 203 having a closed cross-sectional shape can prevent the top plate portion 202 from being out-of-plane deformation. Further, high rigidity can be exhibited even with respect to a compressive load and a tensile load along the extending direction of the curved edge 202a.
[0115]
Subsequently, the manufacturing method and the manufacturing apparatus of the present embodiment will be described below with reference to FIGS. 22 to 32.
[0116]
[Second Embodiment / First Step]
FIG. 22 is a perspective view of each mold and blank 100 used in the first step of the present embodiment. As shown in FIG. 22, in the structural member manufacturing apparatus of the present embodiment, the die 210 on which the blank 100 is placed and the holder 220 that presses the portion of the blank 100 that becomes the top plate portion 202 from above. A punch 230 that forms a concave groove in a portion of the blank 100 that forms the curved reinforcing portion 203, and a drive portion (not shown) that independently drives each of the holder 220 and the punch 230. There is.
[0117]
The die 210 has a top plate support surface 211 that supports a portion of the blank 100 that becomes the top plate portion 202, a mold groove 212 that is connected to the top plate support surface 211, and a horizontal plane 213 that is connected to the mold groove 212. And have. The top plate support surface 211 is a horizontal plane having an edge 211a curved in the same direction as the curved edge 202a and having the same radius of curvature.
[0118]
The mold groove 212 is connected to the top plate support surface 211 at the edge 211a and has the shape shown in FIG. 23. Note that FIG. 23 is a diagram showing the shape of the mold groove 212, in which (a) is an arrow view of NN of (b), and (b) is a side surface seen from a direction orthogonal to the longitudinal direction. It is a figure. In (a) and (b) of FIG. 23, the edge is shown by a thick line in order to clarify the positional relationship of the edge in both figures. Similarly, in each of the following figures, a thick line may be used to indicate the positional relationship.
As shown in FIG. 23, the mold groove 212 is connected to the edge 211a and vertically downward to the mold groove side surface 212a, and is connected to the mold groove side surface 212a and is horizontally separated from the top plate support surface 211. It is provided with a mold groove bottom surface 212b facing the mold groove bottom surface and a mold groove side surface 212c connected to the mold groove bottom surface 212b and facing vertically upward.
[0119]
The height dimension of the mold groove side surface 212a and the mold groove side surface 212c in the vertical direction is different between the central position and the both end positions along the extending direction thereof. That is, when viewed from the side, the upper end edge of the mold groove side surface 212a and the mold groove side surface 212c has a linear shape, while the lower end edge has a convex curved line shape vertically downward. The radius of curvature R of the curved line shape is preferably larger than the radius of curvature R1 of the curved edge 202a in the structural member 201 shown in FIG.The reason will be described later.
[0120]
The height dimension in the vertical direction of the mold groove side surface 212a and the mold groove side surface 212c having the lower end edges of the reverse arch type, respectively, is longer at the center position than at both end positions in the extending direction. ing.
The mold groove side surface 212a and the mold groove side surface 212c have a convex curved shape curved in the same direction as the edge 211a in a plan view. Further, the radius of curvature when the mold groove side surface 212a is viewed in a plan view is equal to the radius of curvature R1 of the curved edge 202a in the structural member 201. Further, the radius of curvature when the mold groove side surface 212c is viewed in a plan view is larger than the radius of curvature of the mold groove side surface 212a. Due to this difference in radius of curvature, the length l12 shown in FIG. 23 (a) is longer at the end position than at the center position in the longitudinal direction of the mold groove bottom surface 212b. As a result, the height dimensional difference along the extending direction of each of the mold groove side surface 212a and the mold groove side surface 212c is absorbed. In other words, the sum of the perimeters, which is the sum of the lengths l11, l12, and l13 shown in FIG. 23 (a), is the same at each position in the extending direction of the mold groove 212. This makes it possible to align the size of the cross-sectional shape of the curved reinforcing portion 203 after molding at each position in the extending direction.
[0121]
The mold groove bottom surface 212b has a convex curved shape that is curved in the same direction as the edge 211a in a plan view. Further, as shown in FIG. 23 (b), the mold groove bottom surface 212b has a height difference h1 in a vertical cross-sectional view between the center position and the end position along the extending direction thereof. That is, the mold groove bottom surface 212b has a concave curved shape that is bent so that the center position is relatively low with respect to both end positions along the extending direction.
[0122]
That is, the mold groove bottom surface 212b has a center position (intermediate position) viewed in a vertical cross section along the extending direction of the mold groove (first mold groove) 212 and both end positions (next to each other) sandwiching this center position. It has a height difference from the position). The pressure surface 230a of the punch (first punch) 230 has a height difference corresponding to the mold groove bottom surface 212b. Further, the mold groove bottom surface 212b forms a curved surface (second mold curved surface) having a convex curved shape in a plan view and a concave curved shape in a vertical cross-sectional view. In the present embodiment, all of the mold groove bottom surface 212b is a curved surface, but the present invention is not limited to this embodiment, and only a part of the mold groove bottom surface 212b may be a curved surface.
[0123]
Returning to FIG. 22, the holder 220 has a convex curved edge 220a having the same radius of curvature in the same direction as the edge 211a, and a flat lower surface 220b that presses the upper surface 100a of the blank 100.
[0124]
The punch 230 has a pressure surface 230a having substantially the same shape as the mold groove 212. The pressure surface 230a is one size smaller than the shape of the mold groove 212 in consideration of the plate thickness of the blank 100.
The pressure surface 230a has a pair of punch outer surfaces 230a1,230a2 and a punch lower end surface 230a3 that connects the lower end edges thereof. The punch outer surfaces 230a1, 230a2 and the punch lower end surfaces 230a3 have a convex curved shape curved in the same direction as the edge 211a in a plan view.
[0125]
The height dimensions of the punch outer surfaces 230a1,230a2 in the vertical direction are different between the center position and the both end positions along the extending direction thereof. That is, when viewed from the side, the upper end edges of the punch outer surfaces 230a1, 230a2 have a linear shape, while the lower end edges have a convex curved line shape vertically downward.
The punch outer surfaces 230a1,230a2 having such inverted arch-shaped lower end edges, respectively, have a height dimension in the vertical direction longer at the central position than at both end positions in the extending direction.
These punch outer surfaces 230a1,230a2 have a convex curved shape that is curved in the same direction as the edge 211a in a plan view. Further, the radius of curvature when the punch outer surface 230a1 is viewed in a plan view is equal to the radius of curvature R1 of the curved edge 202a in the structural member 201. Further, the radius of curvature when the punch outer surface 230a2 is viewed in a plan view is larger than the radius of curvature of the punch outer surface 230a1. Due to this difference in radius of curvature, the length l15 shown in FIG. 22 is longer at the end position than at the center position in the longitudinal direction of the punch lower end surface 230a3. As a result, the height dimensional difference along the extending direction of each of the punch outer surfaces 230a1, 230a2 is absorbed. In other words, the sum of the perimeters, which is the sum of the lengths l14, l15, and l16 shown in FIG. 22, is the same at each position in the extending direction of the punch 230.

The scope of the claims
[Claim 1]
The top plate portion having a curved edge and the cross section formed integrally with the top plate portion along the extending direction of the curved edge and orthogonal to the extending direction of the curved edge have a closed cross-sectional shape or an open cross-sectional shape. It is a method of manufacturing a structural member having a certain curved reinforcing portion from a flat plate material.
By sandwiching the first portion of the flat plate material corresponding to the top plate portion, the second portion connected to the first portion is pressed in a direction intersecting the surface of the flat plate material. In the intermediate step of forming the groove portion and the vertical wall portion connected to the groove portion along the portion of the flat plate material to be the curved edge;
After the intermediate step, a bending step of bending the upper end edge toward the top plate portion by pushing down the upper end edge of the vertical wall portion toward the groove portion while allowing movement toward the top plate portion. ;
Have,
In the intermediate step, the press provides a height difference on the bottom wall of the groove portion between an intermediate position viewed in a vertical cross section along the extending direction of the groove portion and an adjacent position sandwiching the intermediate position. and,
On the bottom wall, a first curved portion having a concave curved shape in a plan view and a convex curved shape in the vertical cross-sectional view, and a second curved portion having a convex curved shape in a plan view and a concave curved shape in the vertical cross-sectional view. A method for manufacturing a structural member, which comprises forming at least one of a curved portion.
[Claim 2]
When the cross-sectional line length along the inner shape of the cross section of the groove portion orthogonal to the extending direction of the groove portion is viewed by the press in the intermediate step, the cross-sectional line length at the intermediate position is set to the adjacent positions on both sides. The ratio divided by the cross-sectional line length in 1 is within the range of 0.7 to 1.3.
The method for manufacturing a structural member according to claim 1.
[Claim 3]
By the press in the intermediate step, the radius of curvature R (mm) of the center line passing through the center position in the width direction in the plan view of the bottom wall is set in at least one of the first curved portion and the second curved portion. The R / R1 ratio divided by the radius of curvature R1 (mm) in the vertical cross-sectional view of the bottom wall is set within the range of 0.2 to 1.2.
The method for manufacturing a structural member according to claim 1 or 2, wherein the structural member is manufactured.
[Claim 4]
After the bending step, there is further a joining step of superimposing and joining at least a part of the upper end edge of the vertical wall portion on the top plate portion to form the curved reinforcing portion having the closed cross-sectional shape.
The method for manufacturing a structural member according to any one of claims 1 to 3, wherein the structural member is manufactured.
[Claim 5]
In the joining process, the movement of the upper end edge beyond the planned joining position on the top plate is restricted.
The method for manufacturing a structural member according to claim 4, wherein the structural member is manufactured.
[Claim 6]
Further has an upper end edge bending step of forming a bent portion in which the upper end edge of the joining step is directed toward the top plate portion before the joining step.
The method for manufacturing a structural member according to claim 4 or 5, wherein the structural member is manufactured.
[Claim 7]
The bending process is
In a plan view facing the top plate portion, at least a part of the upper end edge overlaps the top plate portion, while in a side view, the vertical wall portion is formed until the upper end edge is separated from the top plate portion. By bending it further,
Including a folding step of forming the curved reinforcing portion having the open cross-sectional shape
The method for manufacturing a structural member according to any one of claims 1 to 3, wherein the structural member is manufactured.
[Claim 8]
When the vertical wall portion is further bent in the folding step, the movement of the upper end edge beyond a predetermined position is restricted.
The method for manufacturing a structural member according to claim 7.
[Claim 9]
Further has an upper end edge bending step of forming a bent portion in which the upper end edge toward the top plate portion at the time of the folding step is formed before the folding step.
The method for manufacturing a structural member according to claim 7 or 8, wherein the structural member is manufactured.
[Claim 10]
By forming both the first curved portion and the second curved portion by the press in the intermediate step,
After the bending step, the curved reinforcing portion including both the concave curved shape and the convex curved shape is formed in a plan view facing the top plate portion.
The method for manufacturing a structural member according to any one of claims 1 to 9, wherein the structural member is manufactured.
[Claim 11]
A curved reinforcing portion having a closed cross section having a top plate portion having a curved edge and a cross section formed integrally with the top plate portion along the extending direction of the curved edge and orthogonal to the extending direction of the curved edge. It is a device for manufacturing a structural member having and from a flat plate material.
With the first die on which the first mold groove curved in plan view was formed;
With the first punch that is relatively close and separated from the first mold groove;
With a second die having a second mold groove thinner than the first mold groove in a plan view;
With the first holder having a curved convex portion having a shape corresponding to the second mold groove;
In a plan view, it has a second vertical wall surface that is horizontally opposed to the first vertical wall surface of the first holder at a distance of 5 mm or more and 50 mm or less, with respect to the second mold groove. With a second punch that is relatively close and separated;
With the second holder arranged so as to overlap the second die;
With a pad having a pressure surface that is close to and separated from the second mold groove;
Equipped with
The bottom surface of the first mold groove has a height difference between an intermediate position viewed in a vertical cross section along the extending direction of the first mold groove and an adjacent position sandwiching the intermediate position. ,
The pressure surface of the first punch has a height difference corresponding to the bottom surface of the first mold groove.
The bottom surface of the first mold groove has a concave curved shape in the plan view and a convex curved shape in the vertical cross-sectional view, and a convex curved surface in the plan view. Moreover, it has at least one of the second mold curved surfaces having a concave curved shape in the vertical cross-sectional view.
The gap at the bottom dead center of molding with respect to the first top plate support surface of the second die is larger on the pressure surface of the pad than on the pressure surface of the second holder.
A structural member manufacturing device characterized by this.
[Claim 12]
When looking at the cross-sectional line length of the first mold groove along the inner shape in the cross section orthogonal to the extending direction of the first mold groove, the cross-sectional line length at the intermediate position is taken. The ratio divided by the cross-sectional line lengths at both adjacent positions is in the range of 0.7 to 1.3.
The structural member manufacturing apparatus according to claim 11.
[Claim 13]
At least one of the curved surface of the first mold and the curved surface of the second mold on the bottom surface of the first mold groove has a radius of curvature R1 (mm) in the vertical cross-sectional view and is viewed in a plan view. The R / R1 ratio obtained by dividing the radius of curvature R (mm) of the center line passing through the center position in the width direction is in the range of 0.2 to 1.2.
The apparatus for manufacturing a structural member according to claim 11 or 12, wherein the structural member is manufactured.
[Claim 14]
A curved reinforcing portion having a top plate portion having a curved edge and a cross section formed integrally with the top plate portion along the extending direction of the curved edge and orthogonal to the extending direction of the curved edge is an open cross-sectional shape. It is a device for manufacturing a structural member having and from a flat plate material.
With a third die having a second top plate support surface including a first mold curved edge curved in plan view;
With a third holder that approaches and separates from the second top plate support surface;
With a fourth die having a fourth mold groove arranged adjacent to the curved edge of the first mold in a plan view;
With the fourth punch that approaches and separates from the fourth mold groove;
With a fifth die having a third top plate support surface including a second mold curved edge curved in plan view;
With the 4th holder that is close to and separated from the 3rd top plate support surface;
With a fifth punch having a fourth vertical wall surface arranged horizontally at a distance of 5 mm or more and 50 mm or less with respect to the third vertical wall surface of the fourth holder in a plan view;
With a sixth die having a fourth top plate support surface including a third mold curved edge curved in plan view;
With the fifth holder that approaches and separates from the fourth top plate support surface;
With a sixth punch that has a pressure surface that overlaps the curved edge of the third mold in a plan view and is close to and separated from the sixth die;
Equipped with
The bottom surface of the fourth mold groove has a height difference between an intermediate position viewed in a vertical cross section along the extending direction of the fourth mold groove and an adjacent position sandwiching the intermediate position. ;
The pressurized surface of the fourth punch has a height difference corresponding to the bottom surface of the fourth mold groove.
The bottom surface of the fourth mold groove has a concave curved shape in the plan view and a convex curved shape in the vertical cross-sectional view, and a convex curved surface in the plan view. Moreover, it has at least one of the fourth mold curved surfaces having a concave curved shape in the vertical cross-sectional view.
The gap at the bottom dead center of molding with respect to the fourth top plate support surface of the sixth die is larger on the pressure surface of the sixth punch than on the pressure surface of the fifth holder.
A structural member manufacturing device characterized by this.
[Claim 15]
When looking at the cross-sectional line length of the fourth mold groove along the inner shape in the cross section orthogonal to the extending direction of the fourth mold groove, the cross-sectional line length at the intermediate position is taken. The ratio divided by the cross-sectional line lengths at both adjacent positions is in the range of 0.7 to 1.3.
The structural member manufacturing apparatus according to claim 14.
[Claim 16]
At least one of the curved surface of the third mold and the curved surface of the fourth mold on the bottom surface of the fourth mold groove has a radius of curvature R1 (mm) in the vertical cross-sectional view and is viewed in a plan view. The R / R1 ratio obtained by dividing the radius of curvature R (mm) of the center line passing through the center position in the width direction is in the range of 0.2 to 1.2.
The structural member manufacturing apparatus according to claim 14 or 15.