Technical field
[0001]
　The present invention relates to a structural member.
Background technique
[0002]
　Traditionally, fuselage section of the train or automobile, structure such as a ship is reinforced by combining a plurality of structural members. For example, automobile body floor (hereinafter, simply referred to as "floor") is, when the vehicle traveling not only responsible for the body of the torsional stiffness and bending stiffness primarily, upon collision of the vehicle, the transmission of the impact load responsible. In addition, the floor is also a great influence on the weight of the automobile body. Thus, the floor, it is required to combine the characteristics of the antinomy of high rigidity and light weight. Floor is a flat panel to be joined are welded together, and the vehicle width member having Ryakumizo-section which is fixedly arranged on a flat panel toward the vehicle width direction, flat towards the vehicle body front-rear direction and a vehicle length member having a Ryakumizo-section which is fixedly arranged on the panel.
[0003]
　The flat panel, for example, dash panels, floor panel or the rear floor panel, and the like. Vehicle width member, by welding or the like, is fixedly disposed toward the vehicle width direction of the flat plate-shaped panel, a structural member to increase the rigidity and strength of the floor. The vehicle width member, for example, a floor cross member and the seat cross member and the like. Vehicle length members, by welding or the like, is fixedly disposed toward the vehicle body front-rear direction is a structural member to increase the rigidity and strength of the floor. The vehicle length member, for example, side sills and side members and the like.
[0004]
　Of these, structural members such as the vehicle width member and the vehicle length members are usually joined to another member via the outward flange formed at its end. For example, a floor cross member which is an example of a vehicle width member via an outward flange formed at its both end portions, is joined to another member of the tunnel portion of the front floor panel and the side sill or the like.
[0005]
　27 and 28 show a floor cross member 1 which is a representative example of a member to be joined to another member via the outward flange 4 formed at both ends in the longitudinal direction. Figure 27 is a perspective view of a floor crossmember 1, FIG. 28 is an A arrow view in FIG. 27.
[0006]
　The front floor panel 2, for example, a tunnel portion that is bonded to the upper surface of the front floor panel 2 (the surface of the indoor side) (not shown), it is reinforced by the side sill 3 and the floor cross member 1. Tunnel section, substantially along the center in the width direction of the front floor panel 2, a structural member that bulges to the indoor side. Side sill 3 is spot welded on both sides of the vehicle width direction of the front floor panel 2 on the upper surface of the front floor panel 2. Both ends of the floor cross member 1 through the outward flange 4 formed at both ends in the longitudinal direction, are respectively spot-welded to the tunnel portion and the side sill 3. Accordingly, stiffness and load transfer properties of when an impact load is the load of the floor is improved.
[0007]
　For example, Patent Documents 1 and 2, a structural member that is disposed along the vehicle width direction of the automobile, the groove bottom, an automobile body having a transverse cross-sectional shape of Ryakumizo type having a ridge portion and a vertical wall portion use structural member is disclosed. Among them, the structural members described in Patent Document 1, corresponding to the shape of the member to be joined to the opening side of the cross section of the channel, the height of the vertical wall portion, a becomes higher shape towards the end It has. Furthermore, structural members described in Patent Document 2, the width of the groove bottom portion has a larger shape toward the end.
CITATION
Patent Document
[0008]
Patent Document 1: International Publication No. 2010/073303
Patent Document 2: Laid-Open Patent Publication No. 2009-1227
Summary of the Invention
Problems that the Invention is to Solve
[0009]
　For example, a floor cross member as a structural member is an important structural element that is responsible for absorbing the impact load at the time of the rigidity of the car body improvement and side impact. Therefore, in recent years, from the viewpoint of weight reduction and improvement in collision safety, thinner and higher high-tensile steel sheet strength, for example more than tensile strength 390MPa high tensile steel plate (high-strength steel or high-tensile) of the floor cross member It has been used as the material. However, the floor crossmember, further improvement of the load transmission characteristics of when an impact load is the load is also strongly demanded. Therefore, not just to increase the material strength, by devising the shape of the floor cross member, to improve the load transmission characteristics of when an impact load is the load has become necessary.
[0010]
　Viewpoint above Patent Documents 1 and 2 to the disclosed structural member, the vertical wall portion or the groove bottom portion, has the larger shape toward the end, these shapes, to improve the load transmission characteristics not to have been adopted from. It is not limited to the structural member for an automobile body, also in the structural member provided in other structures, by devising the shape, it is desired to improve the load transmission characteristics of when an impact load is loaded.
[0011]
　Therefore, with the present invention has been made in view of the above problems, it is an object of the present invention, in the structural member elongated having a cross-sectional shape of a substantially channel-shaped, it is possible to weight reduction, to provide a good structural member to the load transfer characteristics at the time of impact load load.
Means for Solving the Problems
[0012]
　In order to solve the above problems, according to an aspect of the present invention, is formed in an elongated extending in a predetermined direction, and a groove bottom, and two ridge portions continuous to both ends in the width direction of the groove bottom portion, the ridge portion in metallic structural member having a two vertical wall portion further continuous, has an end portion in a predetermined direction, at least the groove bottom, an outward flange formed continuously over the ridge and the vertical wall portion, the width of the groove bottom, reduced with distance from the end having an outward flange, the structural member is provided.
[0013]
　Value indicating a reduced degree of the width of the groove bottom portion which is defined by the following formula (1) S (mm -1 ) may be a value within the range of 0.0002 to 0.0018.
　　S (mm -1 ) = {(Wa-Wb) / Wa} / L ...
(1) Wa: width of the groove bottom at the root portion of the end portion having an outward continuous flange
Wb: shrinking the width of the groove bottom any distance the width of the groove bottom at the position of L from the root portion in the range are
[0014]
　In the range from the end portion 100mm or more in length having an outward continuous flange, it may be reduced in width of the groove bottom.
[0015]
　Automobile body structural member through the outward continuous flange, resistance spot welding, laser penetration welding, bonding with fillet arc welding or adhesive, or by combination with joining them may be bonded to another member .
[0016]
　Structural members, the tensile strength may be made from high-tensile steel plate of more than 390 MPa.
[0017]
　Structural members, may be a structural member for a vehicle.
[0018]
　Structural members, the floor cross member, the side sill may be the front side member or a floor tunnel braces.
Effect of the Invention
[0019]
　According to the present invention, by the structural member has an outward continuous flange on the end of a predetermined direction, the initial collapse in the axial direction, is suppressed stress concentration to the end portion of the ridge portion, the stress of another it can be dispersed into portions. Therefore, the load transmission characteristics can be enhanced by reduced distortion of the end of the ridge portion. Further, in the structural member, the width of the groove bottom, by scaling with distance from the end having an outward continuous flange buckling pitch in metaphase and subsequent crushing in the axial direction is reduced. Therefore, even a good load transfer characteristics are maintained in metaphase and subsequent crushing, it can increase the impact energy absorption. Furthermore, the width of the groove bottom, by scaling with distance from the end having an outward continuous flange, weight reduction of the structural member is achieved. In this way, according to the present invention, it is possible to obtain light weight, and superior structural member to the load transfer characteristics at the time of impact load load.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
It is an explanatory diagram showing a configuration example of a structural member (first member) in FIG. 1 embodiment.
Is a cross-sectional view illustrating an example of FIG. 2 the first press forming apparatus.
Is a perspective view showing an example of FIG. 3 the first press forming apparatus.
Is [4] portion which is formed in the groove bottom by the first pad is a sectional view showing a state to be bound.
[5] part to be molded in the groove bottom by the first pad is a perspective view showing a state to be bound.
[6] portion is formed into a ridge portion by the second pad is a sectional view showing a state in which bound.
[7] part to be molded into ridge by the second pad is a perspective view showing a state to be bound.
[8] and the pressing range of the portion is formed into a ridge portion of the second pad is a characteristic diagram showing the relationship between the maximum value of the sheet thickness reduction rate in the flange of the edge of the end portion of the ridge portion.
[9] and the pressing range of the portion is formed into a ridge portion of the second pad is a characteristic diagram showing the relationship between the minimum value of the sheet thickness reduction rate in the vicinity of the root of the flange of the end of the ridge portion.
[10] the die and the forming material by the punch is a sectional view showing a state in which the press forming.
Is a perspective view showing an example using FIG. 11 groove bottom and a pad for pressing a portion to be molded into ridge portion at the same time.
It is a diagram for explaining the forming material when [12] groove bottom and by using the pad for pressing a portion to be molded into ridge simultaneously press molding.
FIG. 13 is an explanatory diagram showing an analysis model according to Example 1 and Comparative Examples 1 and 2.
14 is a graph showing the analysis results on the axial load of the analysis model according to Example 1 and Comparative Examples 1 and 2.
In the case of FIG. 15 crush stroke 10 mm, is a graph that shows the analysis results for the absorption of impact energy.
In the case of FIG. 16 crush stroke 20 mm, is a graph that shows the analysis results for the absorption of impact energy.
FIG. 17 is an explanatory view showing an evaluation method of Examples 2 to 10 and Comparative Examples 3 to 13.
[18] in the case of collapse stroke 5 mm, it is a graph showing the relationship between the reduction degree and the impact energy absorption of the width of the groove bottom.
[19] in the case of collapse stroke 20 mm, it is a graph showing the relationship between the reduction degree and the impact energy absorption of the width of the groove bottom.
In the case of FIG. 20 crush stroke 20 mm, is an explanatory diagram showing the appearance of a buckling analysis model of Example 6 and Comparative Examples 3 and 8.
FIG. 21 is an explanatory diagram showing an analysis model obtained by reducing only the vertical wall portion.
[22] in the case of collapse stroke 5 mm, it is a graph showing the relationship between the reduction degree and the impact energy absorption of the height of the width or the vertical wall portion of the groove bottom portion.
[23] in the case of collapse stroke 20 mm, it is a graph showing the relationship between the reduction degree and the impact energy absorption of the height of the width or the vertical wall portion of the groove bottom portion.
In the case of FIG. 24 crush stroke 20 mm, is an explanatory diagram showing a state of buckling of each analysis model.
[FIG 25 is an explanatory diagram showing an analysis position of the sheet thickness reduction rate of the press-molded body.
FIG. 26 is an explanatory diagram showing an analysis result of the sheet thickness reduction rate.
It is a perspective view showing a floor cross member as FIG. 27 conventional structural members.
An A arrow view of FIG. 28 FIG. 27.
DESCRIPTION OF THE INVENTION
[0021]
　Hereinafter, with reference to the accompanying drawings, it will be described in detail preferred embodiments of the present invention. In the specification and the drawings, components having substantially the same function and structure are a repeated explanation thereof by referring to the figures.
[0022]
<1. Structural members>
(1-1. Configuration Example)
　FIG. 1 is a structural member according to the present embodiment (hereinafter, also referred to as a "first member".) Is an explanatory diagram showing an example of a 10. Figure 1 is a perspective view of the connection structure 100 in which the first member 10 is constructed by joining a second member 18.
[0023]
　The structural member to which the present invention can be applied, for example, automobiles and trains, vehicles chassis represented by a motorcycle or the like, or a reinforcing member of the hull and other structures of the ship is illustrated. These reinforcing members, absorbs the impact energy by crushing during an impact load application, it may be configured to mitigate the impact on the occupant or the like. Hereinafter, taking the structural member for an automobile body as an example, the structural member (first member) 10 will be described.
[0024]
　The first member 10 is, for example, a floor cross member can be used side sill, a front side member or a floor tunnel braces. The first member 10, the floor cross member, the side sill, when used as a reinforcing member for an automobile body such as a front side member or a floor tunnel, tensile strength more than 390MPa as measured by tensile test according to JIS Z 2241 high-tensile steel sheet may be used as a molding material. The tensile strength of the high-tensile steel plate may be more than 590 MPa, or may be further 780MPa or more.
[0025]
　In the present specification, the structural member refers to a first member 10 itself, the second member 18 is a bonded composite structure of joined structure 100 to the first member 10. For example, the first member 10 is the case of the floor cross member, floor panel corresponds to the second member 18. On the other hand, if the first member 10 is used to the side sill, the first member 10, closing plate and, joined structure was bonded to the second member 18 having a similar Ryakumizo-section a first member 100 but it configured as a side sill.
[0026]
　Furthermore, if the first member 10 is used for the front side members, the generally same as the side sill, tubular junction structure in which the first member 10 and a second member 18. as a front side member constructed. However, when the front side member, for example, as the hood ridge panel corresponds to the second member 18, there is a case where the first member 10 itself which is joined to the hood ridge panel called floor side member.
[0027]
　The first member 10, a predetermined direction (hereinafter, also referred to as "axial direction".) Indicated by the arrow X in FIG. 1 is a member of the long formed to extend into. The first member 10 includes a groove bottom portion 11, ridge portions 12a, and 12b, the vertical wall portion 13a, a 13b, the curved portion 14a, and 14b, the flange portion 15a, and a 15b. Two ridge portions 12a, 12b are formed continuously in the width direction of both ends of the groove bottom 11. The two longitudinal wall portions 13a, 13b are two ridge portions 12a respectively, are formed continuously to 12b. The two curved surfaces 14a, 14b are two longitudinal wall portions 13a, respectively, are formed continuously to 13b. Two flanges 15a, 15b are two curved portions 14a, respectively, are formed continuously to 14b.
[0028]
　Also, the two flanges 15a, 15b is, for example, bonded to the second member 18 such as molded panel (e.g. floor panel) constituting the closing plate and the automobile body. Thus, the first member 10 and second member 18, a closed cross-sectional shape is formed. However, the structural member according to the present embodiment, the vertical wall portion 13a, the curved portion 14a continuous to 13b, and 14b, the curved surface portion 14a, a flange portion 15a continuous to 14b, 15b may be omitted.
[0029]
　In such a first member 10, ridge portions 12a, 12b is when an impact load is the load in the axial direction with respect to the first member 10, the portion responsible for loading. Therefore, it is necessary to transmit the load applied to the end portion of the first member 10 efficiently ridge portion 12a, the 12b. Further, in order to absorb efficiently the impact energy by the first member 10, it is necessary to stabilize the impact energy absorption. For this purpose, it is desirable that the buckling pitch of the first member 10 by crushing in the axial direction is reduced.
[0030]
　The first member 10 and second member 18, the flange portion 15a, a bonding method via the 15b, not particularly limited as long as the strength can be secured. In practice, along the longitudinal direction of the joint structure 100, a method of joining by spot welding a plurality of locations it is common. However, for example, by the flange width and the like, may be bonding method by laser welding, it may be other joining methods.
[0031]
(1-2. Outward continuous flange)
　the first member 10 according to this embodiment has an outward continuous flange 16 on the end portion in the longitudinal direction. Outward continuous flange 16, the longitudinal end portion of the first member 10, is formed through the rising curved portion 17 having a radius of curvature r (mm). In the first member 10 shown in FIG. 1, in the longitudinal direction of the end portion, ridge portion 12a from the groove bottom portion 11, 12b, further vertical wall portion 13a, across the 13b, continuously in the cross-sectional circumferential direction, outwardly continuous flange 16 is formed. In this specification, the end portion of the first member 10 having a cross-section of substantially groove-type, a flange bending outward of the groove is referred to as "outward flange", at least ridge portion 12a from the groove bottom 11, the outward flange continuous across 12b as "outward continuous flange".
[0032]
　Outward continuous flange 16, the first member 10, is utilized for bonding to another member (not shown). The first member 10, in the end in the axial direction, via an outward continuous flange 16, for example, are joined by spot welding or the like to the other member made of a steel plate of the pressed bodies. For example, the first member 10, resistance spot welding, penetration welding by laser, or fillet welded by arc, or a combination thereof, is joined to another member. Bonding of the first member 10 and the other member may be a adhesive bonding, the adhesive and the welding may be used in combination.
[0033]
　The first member 10 is, by having such an outward continuous flange 16, the initial collapse in the axial direction with respect to the first member 10 (e.g., crush stroke 5mm or less), the at the end of the first member 10 ridge portions 12a, stress concentration to 12b can be suppressed. Thus, distortion is reduced resulting in the end portion of the ridge portion 12a, 12b, load transfer characteristics in the axial direction of the first member 10 when an impact load is the load is increased.
[0034]
　Outward continuous flange 16, of the longitudinal end portion of the first member 10, may be formed over at least the groove bottom 11 edge line portion 12a, the 12b. Or, outward continuous flange 16, in the longitudinal direction of the end portion of the first member 10 may be formed from the groove bottom 11 vertical wall 13a, to 13b. Further, the outward continuous flange 16, in the longitudinal direction of the end portion of the first member 10, may be divided at a position corresponding to the groove bottom 11.
[0035]
　Furthermore, the outward continuous flange 16 need not be formed over the whole position corresponding groove bottom 11 and the vertical wall portion 13a, to 13b, the groove bottom portion 11 is continuous from at least ridge portion 12a, 12b and the vertical wall part 13a, may be formed at a position corresponding to 13b. With such a outward continuous flange 16 can load applied ridge portions 12a, and 12b are easily dispersed, to suppress the stress concentration to the ridge portion 12a, 12b.
[0036]
　Relates flange width of the outward continuous flange 16, according to the manufacturing method of the structural member to be described later, even the flange width of 25mm or more, by using a high-tensile steel plate, wrinkles less, external cracks is suppressed to form the orientation continuous flange 16. Incidentally, for example, from the viewpoint that facilitates performing spot welding to another member by utilizing the outward continuous flange 16, the flange width may be 13mm or more.
[0037]
　However, the outward continuous flange 16 is a flange having no notch at a position corresponding to the ridge portions 12a, 12b. Therefore, also the flange width of the outward continuous flange 16 is not more 13mm or less, it is possible to maintain the rigidity and collision safety characteristics of the first member 10. Further, from the viewpoint of maintaining the collision safety property, outward continuous flange 16 and the groove bottom portion 11 or the vertical wall portion 13a, the rising angle of the flange is the angle formed between 13b may be 60 ° or more. Note that the "flange provided a notch", is provided over the entire width of the notch the flange means that the flange is discontinuous. The width of the flange is used interchangeably with the height of the flange. Therefore, the width of the flange is partially reduced, when a part of the flange is left is understood not provided a cutout in the flange.
[0038]
　The width of the outward continuous flange 16 may not be uniform over the entire circumference. For example, among the outward continuous flange 16, the flange width in the region corresponding to the ridge portions 12a, 12b may be smaller than other areas. Outward continuous flange 16 at the ends of the ridge portions 12a, 12b, upon press molding, cracks or flange root of wrinkles flange end is likely to occur. Therefore, in the region corresponding to the ridge portions 12a, 12b, as the flange width is narrow, the molding is facilitated. However, the manufacturing method of the structural member to be described later, even when the flange width in the region corresponding to the ridge portions 12a, 12b is relatively large, it is possible to suppress the wrinkles and cracks.
[0039]
(1-3. Info flare)
　The first member 10 according to the present embodiment, the width W of the groove bottom portion 11, decreases as the axial direction, away from the end having an outward continuous flange 16 comprising a previous flare T having a shape. By first member 10 comprises a previous flare T, it can cause buckling in the order from the end of the first member 10. Further, since the first member 10 is provided with a previously flare T, crushing after the middle of the axial direction with respect to the first member 10 (e.g., crush stroke 5mm greater), the accompanying crushing of the first member 10 buckling pitch decreases, increases suppositories屈数, the impact energy absorption can be stabilized.
[0040]
　Thus, the load transmission characteristics of when an impact load is the load is further increased. Further, since the first member 10 is provided with a previously flare T, the length of the cross section of the end portion having an outward continuous flange 16 (hereinafter, also referred to as "cross-sectional peripheral length".) The same case, the first the member 10 may weight. Further, the first member 10 by providing the above flare T, when bending or twisting the vehicle body is loaded, the junction of the other part, the end portion having an outward continuous flange 16 it is possible to alleviate the stress concentration. Thus, it is possible to improve the vehicle body bending and torsional stiffness.
[0041]
　Here, when the reduction degree of the width W of the groove bottom portion 11 is too small, the effect of the stabilizing effect and weight of the impact energy absorption is difficult to obtain. On the other hand, when the reduction degree of the width W of the groove bottom portion 11 is too large, although the first member 10 is more lightweight, too small cross-sectional perimeter of the first member 10, a small impact energy absorption there is likely to be. Accordingly, in a first member 10, a value indicating a reduced degree of the width W of the groove bottom 11 which is defined by the following formula (1) S (mm -1 ) is a in the range of 0.0002 to 0.0018 at best, it may also be in the range of 0.0004 to 0.0015.
[0042]
　　S (mm -1 ) = {(Wa-Wb) / Wa} / L ...
(1) Wa: the width of the groove bottom 11 at the base portion of the end portion having an outward continuous flange 16
Wb: the width of the groove bottom portion 11 is the width of the groove bottom 11 at the position of an arbitrary distance L from the root portion in the range in which reduced
[0043]
　Incidentally, if the reduction ratio of the width W of the groove bottom portion 11 is changed in the axial direction, the value S indicating the reduction degree of the above is defined as the average of the values ​​S indicating a reduced degree obtained by a plurality of distance L. Average of the values ​​S indicating a reduced degree, for example, within the range previously flare T are provided, the distance L is increased by 10mm intervals, the value S calculated by the equation (1) at each distance L it can be an average value.
[0044]
　Further, in the direction along the axial direction of the first member 10, a range previously flare T is provided may be set according to the amount of deformation of the axial direction of the first member 10 when an impact load load. For example, if the first member 10 is a floor cross member, the maximum deformation amount of the first member 10 is assumed to be 100 mm, range previously flare T is provided, the groove bottom portion 11 and the rising curved portion 17 it can be from the boundary portion between at over 100 mm.
[0045]
　Also, when the range previously flare T are provided is too long, cross-sectional peripheral length of the first member 10 at a position away from the end outwardly continuous flange 16 is provided is shortened, withstand impact load there is no fear. Thus, for example, if the first member 10 is a floor cross member, the range previously flare T is provided, it may be 300mm or less.
[0046]
<2. Method for manufacturing a structural member>
　has been described above configuration of the first member 10 as automobile body structural member according to the present embodiment. Manufacturing methods and manufacturing apparatus of the first member 10 is not particularly limited. However, if the first member 10 is manufactured by using a metal plate, in particular high-tensile steel sheet, due to restrictions on the molding, in outward continuous flange 16 is formed continuously to the end of the ridge portion 12a, 12b cracking and the flange edge, ridge portions 12a, wrinkles are likely to occur near the base of the flange in the vicinity of the end portion of 12b.
[0047]
　Of trouble during these molding, the higher the material strength of the molding material and the higher stretch flange rate during flange molding at a position corresponding to the ridge portion is at high shape (bending angle of the ridge portion 1a in FIG. 28 θ is about is steep) likely to occur. Also. Malfunction during these molding, as the height of the first member 10 (the height h in FIG. 28) is high, it tends to occur. In particular, in the case of the first member 10 having a previously flare T, the aforementioned wrinkle is further easily generated.
[0048]
　Hereinafter, while preventing cracking and wrinkling of such edges, the first member 10, one example of a manufacturing method of the structural member which can be manufactured by press molding will be described with reference to high-tensile steel plate. Hereinafter, after describing the outline of the manufacturing method of the structural member, for example of a manufacturing method of a configuration example and a structural member of the press-forming apparatus will be described in detail.
[0049]
(2-1. Outline of Manufacturing Method)
　First, the outline of one example of the method for manufacturing a structural member by press forming. Examples of a method of manufacturing a structural member to be described below includes a first step performed by using the first press forming apparatus, and a second step performed by using the second press forming apparatus.
[0050]
(2-1-1. Outline of First Step)
　The first step is carried out using the first press forming apparatus. In the first step, the first pad at least a part of the portion to be molded to the groove bottom portion of the molding material is pressed. Thus, the ends of the molding material to be continuous to the portion to be molded in the groove bottom, it is raised in a direction opposite to the pressing direction of the first pad. Furthermore, molding material by the first pad is pressed against the first punch, the first pad and a first punch, at least a portion of the part to be molded into the groove bottom portion is restrained.
[0051]
　After the portion is formed into a groove bottom of the molding material by the first pad is constrained by a second pad which is different from the first pad, the longitudinal end of the portion to be molded into ridge portion of the molding material At least a portion of the section is pressed. Thus, the ends of the molding material to be continuous to the portion to be molded into ridge portion, it is raised in a direction opposite to the pressing direction of the second pad. Further, the second pad, while bent portions are formed in the ridge portion in the molding material in the pressing direction of the second pad, the second pad and the first punch, at least in part to be molded into ridge part is restrained.
[0052]
　In a state where the molding material is constrained by the first pad and the second pad and the first punch, the first die is brought close to the first punch, the molding material is press-molded. Such a first step, the end portion in the longitudinal direction, and having an outward continuous flange cracks is suppressed, preform wrinkles in the vicinity of the end portion of the ridge portion is suppressed is formed.
[0053]
(2-1-2. The second step of the schematic)
　second step is carried out by using the different second press forming apparatus includes a first press forming apparatus. In the first step, to use the second pad to restrain the portion to be molded to the first pad and the ridge portion that restrains a portion to be molded in the groove bottom, the first die and the first punch , completely there is a part of the molding material that can not be pressed. Thus, in the second step, by the intermediate molded body is press-molded by a second punch and a second die, the structural member is molded.
[0054]
　The second press forming apparatus includes a first press forming apparatus as long as the part which can not be molded can press molding. Specifically, the second press-forming device, the groove bottom, of the part to be molded into ridge portion and the vertical wall, as long as the regions are not restrained by the first pad or the second pad may press molding Bayoi. Furthermore, the second press-forming device, a portion of the outward continuous flange which can not be molded in the first press forming apparatus may be configured to press-forming. Such second press forming apparatus may be configured by a known press molding apparatus having a die and punch.
[0055]
(2-2. Manufacturing apparatus)
　Next, a configuration example of a press molding apparatus. 2 and 3 are schematic configuration diagram illustrating an example of a first press forming apparatus 30. 2, the first press forming apparatus 30 is a cross-sectional view schematically showing a portion for forming the region of the end portion of the intermediate form, FIG. 3, the first press forming apparatus 30 schematically it is a perspective view showing. In Figure 3, the first punch 31 and the first pad 34-1, the longitudinal half portion divided by a center line along the intermediate formed body for molding is shown.
[0056]
　The first press forming apparatus 30, includes a first punch 31, and the first die 32, and a first pad 34-1 and a second pad 34-2 facing the first punch 31 there. Such first press forming apparatus 30 is basically in a state of restraining the molding material by a first pad 34-1 and the second pad 34-2 and the first punch 31, the first die 32 by the closer to the first punch 31 and a molding material as press molding devices.
[0057]
　The first punch 31 has a punch surface on the side facing the first die 32, a first pad 34-1 and the second pad 34-2. The first punch 31 has a top surface 31a, a shoulder 31b for forming the ridge portion of the preform and a flange forming portion 31c.
[0058]
　The first pad 34-1 has a restraining surface 34-1a, and a flange molding portion 34-1b. Restraining surface 34-1a of the first pad 34-1 is disposed opposite to the upper surface 31a of the punch 31, to restrain the molding material by pressing a molding material with respect to the upper surface 31a of the punch 31. Portion of the molding material to be bound by the restraining surface 34-1a and the top surface 31a is a portion which is formed in the groove bottom. Portion of the molding material to be bound may be a whole part to be molded in the groove bottom, it may be a part. However, of the portions that are formed in the groove bottom, end portion of at least the side of the outward continuous flange is molded to be constrained. Flanging portion 34-1b of the first pad 34-1 presses the molding material against the flange-forming portion 31c of the punch 31. Thus, it is raised flange portion formed at an end portion of the groove bottom portion in the molding material.
[0059]
　Second pad 34-2 has a restraining surface 34-2a, and a flange molding portion 34-2B. Second pad 34-2, at the time of press forming, are arranged so as not to interfere with the first pad 34-1. Restraining surface 34-2a of the second pad 34-2 is disposed opposite to the shoulder portion 31b of the punch 31, to restrain the molding material by pressing the molding material against the shoulder portion 31b of the punch 31. Portion of the molding material to be bound by the restraining surface 34-2a and the shoulder portion 31b are at least part of the end region of the portion to be formed into a ridge portion. Flanging portion 34-2b of the second pad 34-2 presses the molding material against the flange-forming portion 31c of the punch 31. Thus, it is raised flange portion formed at an end portion of the ridge portion in the molding material.
[0060]
　Such second pad 34-2, with the part to be molded into the groove bottom portion by the first pad 34-1 is restrained, restraining the part to be molded into ridge portion in the region near the outward continuous flange to. Therefore, the shape of the ridge portion in the region near the outward continuous flange is formed by causing overhang the material part which is pressed substantially by the second pad 34-2. Therefore, the second pad 34-2 is suppressed movement of the material around the abutting portion, elongation and contraction deformation of the surrounding material causing wrinkles and cracks is suppressed. Accordingly, in outward continuous flange, it can be suppressed and stretch flange crack in the flange portion corresponding to the ridge portion, the occurrence of wrinkles in the vicinity of the root of the flange at the edge line portion of the vicinity of the end portion of the ridge portion.
[0061]
　The second pad 34-2 in the vicinity of the outward continuous flange, is aimed at suppression of the movement of the surrounding material by by overhang the material of the region forming the ridge portion. Therefore, the second pad 34-2 in the vicinity of the portion to be molded outwardly continuous flange, starting from the connection portion with the portion to be formed into a part and the groove bottom portion which is molded into ridge portion, the ridge portion the entire area of ​​the portion to be molded may be restrained.
[0062]
　Specifically, part of the molding material to be bound by restraining surface 34-2a of the second pad 34-2, include a connecting portion between the portion to be formed into a part and edge line portion which is formed in the groove bottom It is preferred. In particular, among the portion to be formed into a ridge portion 12a, 12b, the length of the portion of the cross-section perimeter of at least one third originating the connection portion may be pressed by the second pad 34-2 . By the second pad 34-2 presses the portion, while suppressing the movement of the periphery of the steel sheet material, leaving tension steel plate material of the portion pressed by the restraining surface 34-2a of the second pad 34-2 is not able to form part of the ridge portion 12a, 12b with. The second pad 34-2, in addition to the ridge portion, a portion of the vertical wall portion, for example, has become such a manner as to press 20mm less length portion of one of the vertical wall portion continuous to the ridge it may be.
[0063]
　Other, other elements, such as the dimensions and material of the first pad 34-1 and the second pad 34-2 can be the same structure as the known pad.
[0064]
　The first die 32, while constraining the molding material by a first pad 34-1 and the second pad 34-2, is proximate the first punch 31, the molding material is press-molded. The first die 32, at the time of press forming, are arranged so as not to interfere with the first pad 34-1 and the second pad 34-2. Preferably, the first pad 34-1, the second pads 34-2 and the first die 32, may be disposed with minimal clearance relative to the pressing direction.
[0065]
　Here, in the first press forming apparatus 30, configured to the first pad 34-1, the second pads 34-2 and the first die 32 presses the molding material in this order. That is, the second pad 34-2, after at least a portion of the part to be molded into the groove bottom portion is restrained by the first pad 34-1, restraining the area of ​​the end of the portion to be formed into a ridge portion to. The first die 32 in a state where the molding material is constrained by the first pad 34-1 and the second pad 34-2, a molding material is press-molded.
[0066]
　For example, the die 32, through the coil spring, by suspending a first pad 34-1 and the second pad 34-2, capable of realizing such a configuration. At this time, in a state before press-forming, restraining surface of the first pad 34-1 34-1a, restraint surface 34-2a and the pressing surface of the first die 32 of the second pad 34-2, the first It is disposed from the punch 31 side so as to be positioned in this order. Then, by moving toward the first die 32 to the first punch 31, a first pad 34-1 and the second pad 34-2, in this order, the molding material in contact with the molding material after restraint, the first die 32 is press-molding the molding material.
[0067]
　However, the first pad 34-1, one or all of the second pads 34-2 and the first die 32, individually, be configured to be movable toward the first punch 31 it may be. In this case, each of the first pad 34-1, by controlling the movement of the second pads 34-2 and the first die 32, abutting order is controlled in the molding material.
[0068]
　Note that by first pad 34-1 or the second pad 34-2 is present, the area which can not be pressed against the molding material to the first punch 31 is present by the first die 32. For example, in the pressing direction, the vertical wall portion and a flange portion overlapping with the second pad 34-2 can not be press-molded by the first die 32. Such regions are press-molded in a second step carried out by using the second press forming apparatus. The second press forming apparatus, which can be constituted by a known press molding apparatus, the description thereof is omitted.
[0069]
(2-3. Production Method)
　Next, specifically described one example of a method for manufacturing the structural member. Examples of a method of manufacturing a structural member to be described below, illustrated in FIG. 1, an example of a manufacturing method of the first member 10 having an outward continuous flange 16 and the above flare T.
[0070]
(2-3-1. The first step)
　4 to 10 are explanatory diagrams showing a first step performed by using the first press forming apparatus 30 previously described. 4 and 5 are a sectional view and a perspective view schematically showing a state in which the molding material 33 is restrained by the first pad 34-1. Further, FIGS. 6 and 7 are a sectional view and a perspective view schematically showing a state in which the molding material 33 is restrained by the second pad 34-2. Figure 10 is a molding material 33 by the first die 32 is a sectional view showing a state in which the press forming schematically.
[0071]
　Incidentally, FIGS. 4 to 10 shows how the first step in manufacturing the first member 10 of the previous spreading shape. Further, FIGS. 4, 6 and 10, in the first step, of the molding material 33, which shows a state of forming the region of the longitudinal end outward continuous flange 16 is formed. Further, in FIGS. 5 and 7, the first punch 31, a first pad 34-1 and the molding material 33, is shown a longitudinal half portion divided by a center line along the intermediate formed body for molding there. Furthermore, in the manufacturing method described below, the first pad 34-1 and the second pad 34-2 first press forming apparatus 30 is used which is suspended on the first die 32.
[0072]
　In the first step, first, as shown in FIGS. 4 and 5, the first die 32 with the moving toward the first punch 31, a first pad 34-1, the molding material constraining the part to be molded into the groove bottom portion 11 in 33. At this time, as shown in FIG. 5, at least a portion of the part to be molded into the groove bottom portion 11 in the molding material 33 is restrained by the restraining surface 34-1a of the first pad 34-1. At the same time, the longitudinal end portion of the forming material 33 is raised in a direction opposite to the pressing direction, the flange forming portion 31c of the flange-forming portion 34-1b of the first punch 31 of the first pad 34-1 It is bound by the.
[0073]
　Then, as shown in FIGS. 6 and 7, the first die 32 with the further moves toward the first punch 31, the second pad 34-2, the ridge line portion 12a in the molding material 33 , restraining the part to be molded 12b. Portion of the molding material 33 to be bound at this time is the end portion in the vicinity of the part to be molded ridge portion 12a, the 12b. That is, as shown in FIG. 7, the end of the portion to be formed into a ridge portion 12a, 12b of the molding material 33 is restrained by the restraining surface 34-2a of the second pad 34-2. At the same time, the ridge line portion 12a, the portion that is molded to the flange continuously from the portion to be molded to 12b are raised further up in the opposite direction to the pressing direction, the flange forming portion of the second pad 34-2 34- 2b and is restrained by the flange-forming portion 31c of the first punch 31.
[0074]
　In this case, among the parts to be molded ridge portion 12a, a 12b, the length of the portion of the at least one third of the cross-sectional circumference which starts the connection part, it is pressed by the second pad 34-2 good. By the second pad 34-2 presses the portion, while suppressing the movement of the periphery of the steel sheet material, leaving tension steel plate material of the portion pressed by the restraining surface 34-2a of the second pad 34-2 is not able to form part of the ridge portion 12a, 12b with.
[0075]
　8, the pressing range of the portion is formed into a ridge portion of the second pad 34-2, the ridge line portion 12a in the outward continuous flange 16 formed, sheet thickness reduction rate in the edge of the flange portion continuing to 12b is an explanatory view showing the relationship between the maximum value of. In such 8, pressing range, presser means central angle at a position where the second pad 34-2 restrains the connecting portion between the portion to be formed into a part and the groove bottom portion which is molded into ridge as 0 ° It is indicated by the angle. The presser angle 0 °, the portion to be molded into ridge means a state that is not constrained.
[0076]
　As shown in such FIG. 8, when the part to be molded into ridge portion not being bound, the maximum value of the sheet thickness reduction rate in the flange of the edge has become about 36%, possibly stretch-flange cracking occurs it can be seen that high. On the other hand, the pressing angle is 23 ° or more, i.e., if at least one third ridge portion of the cross-sectional circumference which starts the connection portion is long as it is constrained, the maximum value of the sheet thickness reduction rate in the flange of the edge is less than 25% It is reduced to. Therefore, it can be seen that cracking of the flange of the edge is suppressed.
[0077]
　Further, FIG. 9, the pressing range of the portion is formed into a ridge portion of the second pad 34-2, the ridge line portion 12a is formed, a minimum of 12b the plate thickness reduction rate at the base near the end portion of the flange it is a characteristic diagram showing the relationship between the value. Also in such a 9, the pressing range is indicated by the pressing angle in the same manner as in FIG. As shown in such FIG. 9, when a portion to be molded into ridge portion not being bound, the minimum value of the sheet thickness reduction rate in the vicinity of the root of the flange has become about 65%, clearly that wrinkles It can be seen. On the other hand, the pressing angle is 23 ° or more, i.e., if at least one third ridge portion of the cross-sectional circumference which starts the connection portion is long as it is constrained, the minimum value of the sheet thickness reduction rate in the vicinity of the root of the flange -35 % it is suppressed more than in. Therefore, it can be seen that wrinkles near the base of the flange can be suppressed.
[0078]
　Then, as shown in FIG. 10, the first die 32 with the further moves toward the first punch 31, the molding material 33 by the first pad 34-1 and the second pad 34-2 There while being restrained by a first punch 31 and the first die 32 is press-formed in the first stage is carried out. Thus, along the pressing direction, a second portion located below the pad 34-2 except (Figure 33A 10) or the like, the molding material 33 is press-formed, the intermediate molded body is molded.
[0079]
　First stage of the press molding using a first punch 31 and the first die 32 is bent to press the molding material 33 by the first die 32, a bending pressed against the first punch 31 good. Alternatively, press molding according first stage is the first die 32 and the blank holder, with clamping the part to be molded into the vertical wall portion in the molding material 33, the first die 32 and the blank holder first It moved to mold toward the punch 31, may be a deep drawing.
[0080]
　At this time, the second pad 34-2, the end portion of the portion to be molded ridge portion 12a, the 12b (near the juncture between the ridge portions 12a, 12b and the outward continuous flange 16) is constrained from occurrence of wrinkles in the area is suppressed. Further, since the relevant region is constrained by a second pad 34-2, the ridge line portion 12a, reduced flange stretch flange rate of which is continuously formed in an end portion of the 12b, the outward continuous flange 16 it is possible to suppress the cracking. Although not shown in FIGS. 4 to 10, the curved portion 14a of the first member 10 illustrated in FIG. 1, 14b and the flange portion 15a, 15b is part of, in the first step, the first It is press-formed by the punch 31 and the first die 32.
[0081]
　The method of manufacturing a structural member, ridge portions 12a, wrinkles around the root of the flange of the end regions of 12b, and why cracking of edges of the outward continuous flange 16 is suppressed will be described below. 11 and 12 are not the first pad and the second pad is divided, the press molding using a pad 134 for restraining a portion to be molded into the part and the edge line portion is formed in the groove bottom at the same time it is an explanatory view showing a state. Structural members to manufacture is a structural member having a previous flare T illustrated in FIG. Figure 11 is a view corresponding to FIG. 7, the punch 131 and the pad 134, a perspective view showing a state where the portion to be formed into a part and the ridge line portion is formed in the groove bottom portion in the molding material 133 is constrained is there. Further, FIG. 12 is a view of the molding material 133 as it is pressed by the die from above.
[0082]
　When using such a pad 134, when the pad 134 to constrain pressing a molding material 133 in the punch 131, first, the portion to be molded into ridge portion is pressed by the pad 134. In this state, a gap is formed between the portion and the pad 134 that is formed in the groove bottom portion is formed in the groove bottom portion is not pressed by the pad. Further, in the case of a structural member having previously spread shape, in the vicinity of the end portion of the portion to be formed in the groove bottom, the position thus sectional circumferential length difference in the longitudinal direction are present. That is, as shown in FIG. 11, the position Z 1 sectional circumferential length at the position Z 2 longer than the cross section circumferential length at.
[0083]
　Then, as shown in FIG. 11, the pads 134, until the portion to be formed into a part and the ridge line portion is formed in the groove bottom portion are both bound, it is formed into a ridge portion from the portion to be formed in the groove bottom subjected part that, the steel sheet material of the portion to be molded outwardly continuous flange is to move.
[0084]
　Furthermore, in the case of a structural member having a previous flare, is bent by the die, the portion that is molded into the vertical wall, as shown in FIG. 12, in a direction perpendicular to the portion 112 which is molded into ridge , i.e., bent in a direction away from the portion 116 to be molded outwardly continuous flange. Therefore, the steel sheet material of the part being molded outwardly continuous flange, easily move toward the portion to be further molded into ridge portion. Therefore, the portion to be formed into a ridge portion, excessive wrinkles and thickening is more likely to occur. For this reason, in the case of using the pads 134 for restraining a portion to be molded into the part and the edge line portion is formed in the groove bottom at the same time it is molded to the end portion and the ridge portion of the portion to be molded into the groove bottom portion wrinkle is likely to occur at the end of the part that.
[0085]
　In contrast, in the illustrated manufacturing method, as shown in FIGS. 5 and 7, after the part to be molded into the groove bottom portion is restrained by the first pad 34-1, the ridge line by a second pad 34-2 end of the portion to be molded is constrained by being pressed to the section. Thus, while the end of the portion to be formed into a ridge portion is pressed by the second pad 34-2, the movement of the steel sheet material to the portion to be molded into the groove bottom portion is suppressed. Therefore, even if there is cross-sectional circumferential length difference depending on the position in the longitudinal direction at the end of the portion to be formed in the groove bottom (near the outward continuous flange), the steel plate portion is molded outwardly continuous flange material, to move to the portion which is molded into the part and the edge line portion is formed in the groove bottom portion is suppressed.
[0086]
　Further, in a state where the part to be molded in the groove bottom by a first pad 34-1 is restrained, since the end of the portion to be formed into a ridge portion is pressed by the second pad 34-2, the ridge line end of the portion to be formed into a part is molded by causing overhang the steel material part to be the pressing. Further, in a state where the molding material 33 is restrained by the first pad 34-1 and the second pad 34-2, as shown in FIG. 10, the forming material by the first punch 31 and the first die 32 33 is press-molded. Therefore, excessive steel material to the portion to be molded into ridge portion that is moved is suppressed. As a result, ridge portion 12a is formed, the excess thickness increase and wrinkles at the edge of 12b is suppressed.
[0087]
(2-3-2. The second step)
　after the press forming of the first stage at least the first step in the above, in the second step is press-formed in the second stage is performed. In the first step, along the pressing direction, of the portion corresponding to the lower portion of the second pad 34-2, a vertical wall portion 13a that overlaps the second pad 34-2, the portion to be molded to 13b, the It can not be molded into the final shape of the first member 10. Further, the curved surface portion 14a of the first member 10, 14b and the flange portion 15a, even for all or part of the portion to be molded to 15b, in a first step, there may not be molded into a final shape.
[0088]
　Further, on the molding material 33, depending on the region where the first pad 34-1 and the second pad 34-2 presses, some of the parts being molded ridge portions 12a, and 12b also, the first in step may not be molded into a final shape. For example, in a first step, the ridge line portion 12a, out of the portion to be formed into a 12b, cross sectional circumference which starts the connection portion with the portion to be formed into a part and the groove bottom portion 11 that is shaped ridge portion 12a, 12b, when the one-third of the length is formed by the second pad 34-2, it is necessary to shape the remaining 2/3 of the cross sectional circumference.
[0089]
　Thus, in the second step, using the second press forming apparatus performs press molding of the second stage with the intermediate molded body by the second punch and a second die, the first of the final shape molding the member 10. The second step, using a second punch and a second die having a pressing surface corresponding to the shape of the part to be molded into a final shape, can be performed by a known press molding. When it is not be molded to the first member 10 as a final shape in the second step may further add another molding process.
[0090]
　The second step is performed without using the pad, the die and may be only stamping press forming by the punch, it may be a conventional press molding is performed using a pad.
[0091]
<3. Effect>
　As described above, the first member 10 according to this embodiment has a previous flare T, by having an outward continuous flange 16 at its end, the load at the time of collapse in the axial direction it is possible to improve the transfer characteristics and impact energy absorption. Specifically, the first member 10, by having an outward continuous flange 16 to the end, the initial collapse in the axial direction, the ridge line portion 12a, the stress concentration to the end portion of 12b is suppressed, the stress it can be the dispersed to other portion. Thus, ridge portions 12a, distortion of the end portion of 12b becomes small, the load transmission characteristics can be enhanced. Further, since the first member 10 has a previous flare T, it is possible to reduce the buckling pitch in metaphase and subsequent crushing in the axial direction. Therefore, I can coupled with that increased load transfer characteristics, it is possible to increase the impact energy absorption. The first member 10, by having the above flare T, shrinking the width of the groove bottom portion 11 moves away from the end portion having an outward continuous flange 16, cross-sectional perimeter of the first member 10 is small Become. Therefore, according to this embodiment, it is possible to reduce the weight of the first member 10.
Example
[0092]
　Hereinafter, a description will be given of an embodiment of the present embodiment. In the description of the following examples, the first member 10 as automobile body structural member according to the present embodiment will be described as a press-molded body 10.
[0093]
(1) impact energy absorbing characteristic evaluation
　First, given the impact load in the axial direction from the end portion having an outward continuous flange 16 in the press-molded body 10 is manufactured by way of example in the above-described manufacturing method of the structural member, the impact energy It was to evaluate the amount of absorption.
[0094]
　Figure 13 is an explanatory diagram showing an analysis model of the structure member used for analysis. 13, from the top, showing the analysis model 70 according to Comparative Example analysis model 50 in accordance with 1, the analysis model 60 according to Comparative Example 2 and Example 1. Any of analytical models 50, 60, 70 is also pressed bodies 10,51,61 having a cross-section of substantially groove-type, the curved surface portion 14a, a flange portion 15a continuous vertical wall portion 13a, and 13b through 14b, through 15b, it is joined to the plate-like second member 18.
[0095]
　Analysis model 50 according to Comparative Example 1, the end portion in the axial direction, having no notch outward continuous flange 23. However, the analysis model 50, the width of the groove bottom has a constant shape. The width Wa of the groove bottom portion, Wb is 100 mm. The height of the press-molded body 51 is 100 mm. Further, the boundary portion between the rising curved portion 17 and the groove bottom portion, the length Lx to no end an outward flange is 300 mm. The value S indicating a reduced degree of the width of the groove bottom portion which is defined by the formula (1) is zero. Pressed bodies 51 of such analysis model 50 is intended to be formed by press molding using a pad (pad 134 of FIG. 11) for restraining a portion to be molded into parts and ridge portion is formed in the groove bottom at the same time .
[0096]
　Analysis model 60 according to Comparative Example 2, the end portion in the axial direction has a discontinuous outward flange 24 having a notch reaches the end of the ridge portion 12a, 12b. Also, the analysis model 60 has a shape to reduce the width of the groove bottom portion with distance from the end having an outward flange 24. Minimum width of the groove bottom (width Wb) is 100 mm, the maximum value (width Wa) is 130 mm. The height of the press-molded body 61 is 100 mm. Further, the boundary portion between the rising curved portion 17 and the groove bottom portion, the length Lx to no end an outward flange 24 is 300 mm. The value S indicating a reduced degree of the width of the groove bottom portion which is defined by the formula (1) is 0.00077. Pressed bodies 61 of such analysis model 60 is intended to be formed by press molding using a pad restraining only the part to be molded in the groove bottom.
[0097]
　Analysis model 70 according to the first embodiment, the axial ends, having no notch outward continuous flange 16. Also, the analysis model 70, in the same manner as in Comparative Example 2 has a shape in which the width of the groove bottom towards the end with an outward flange 24 is increased. Minimum width of the groove bottom (width Wb) is 100 mm, the maximum value (width Wa) is 130 mm. The height of the press-molded body 10 is 100 mm. Further, the boundary portion between the rising curved portion 17 and the groove bottom portion, the length Lx to no end outward continuous flange 16 is 300 mm. The value S indicating a reduced degree of the width of the groove bottom portion which is defined by the formula (1) is 0.00077. Pressed bodies 10 of such analysis model 70 is intended to be formed by press molding using a first pad 34-1 and second pads 34-2 shown in FIGS. 4-10.
[0098]
　Analysis conditions other than those described above, were all analysis model 50, 60, 70 and the same. Common analysis conditions are as listed below.
· Use steel sheet: tensile strength 980MPa grade high tensile steel, thickness 1.4 mm
, ridge curvature radius: 12 mm
, flange portion 15a, the curved portion 14a continuous to 15b, 14b of the curvature radius: 5 mm
, outward continuous flange 16 and the outward flange 24 of width: 14 mm
curvature, the rising curved portion 17 radius r: 3 mm
[0099]
　In performing the analysis, as shown in Comparative Example 1, the rigid wall 29, the outward continuous flange 16, 23 or from the outward flange 24 is formed with an end portion side in the axial direction, the collision speed of 20 km / h collide, giving an axial displacement with respect to the analysis model 50, 60, 70. Then, in each of Example 1 and Comparative Examples 1 and 2 was calculated as the axial load generated upon collision (kN), the absorption amount of impact energy a (kJ).
[0100]
　14, each analysis model 50, 60, 70, is a graph showing the analysis results on the axial load. In order to eliminate the cross-section of the circumferential length effect of the end of the analysis model 50, 60, 70, the vertical axis of the graph in Figure 14, the axial load, the boundary between the rising curved portion 17 and the groove bottom portion divided by the cross-sectional peripheral length (axial load / peripheral length: kN / mm) was. The A sectional circumference of the case, means a pressed bodies 10,51,61 length of the plate thickness center of each cross-section which does not contain the second member 18.
[0101]
　Crush stroke following 5 mm, in the initial region St1 crush in the axial direction, the analysis model 50, 70 of Example 1 and Comparative Example 1 having a notch no outward continuous flange 16 and 23, notches compared to the analysis model 60 of Comparative example 2 having a certain outward flange 24, an axial load (kN / mm) it is enhanced. Further, in the region St2 crush stroke 5mm greater, the analysis model 60, 70 of Example 1 and Comparative Example 2 having the above flare, as compared with the analytical model 50 of Comparative Example 1 is the width of the groove bottom is constant , axial load (kN / mm) is enhanced substantially.
[0102]
　Analysis model 70 according to Example 1 with a press-molded body 10 having an outwardly continuous flange 16 and the above flare is stage to the late stage from the initial crushing in the axial direction, it is realized a high axial load. In particular, the analysis model 70 according to the first embodiment, the crush stroke of 15mm than maintains a high axial load even in late collapse in the axial direction.
[0103]
　Further, FIGS. 15 and 16, respectively the analysis model 50, 60, 70, is a graph that shows the analysis results for the absorption of impact energy (E. A.). Figure 15 is a collapse stroke St represents the analysis result in the case of 10 mm, 16, collapse stroke St indicates the analysis result of the case of 20 mm.
[0104]
　As shown in FIG. 15, the end portion in the axial direction, the analysis model 50, 70 having an outward continuous flange 16 and 23 with no notch, compared to the analysis model 60 having an outward flange 24 in Kino Kikkake it can be seen that the collapse stroke St is increased impact energy absorption in the case of 10 mm. Further, as shown in FIG. 16, the analysis model 60, 70 having previously flare, as compared with the analysis model 50 width is constant groove bottom, the impact energy absorbing amount when collapse stroke St of 20mm is increased it can be seen.
[0105]
　Thus, the load transmission characteristic of the analysis model 70 according to the first embodiment, even in the early and late timing of any collision, than the analysis model 60 in accordance with the analytical model 50 and Comparative Example 2 according to Comparative Example 1, it can be seen that excellent impact energy absorption properties.
[0106]
(2) Effect of reduction degree evaluation
　Next, by changing the reduction degree of the width of the groove bottom of the pressed bodies 10,61 of the analysis model 60, 70 of Example 1 and Comparative Example 2 described above, for the impact energy absorption It was to evaluate the effect of reducing the degree. Examples 2-10 and Comparative Example 3, the pressed bodies 10 of the first embodiment described above, the end portion having an outward continuous flange 16 by varying the width Wb of the groove bottom portion of the opposite end, it is obtained by changing the reduction degree. Further, Comparative Examples 4 to 13, in a press molded body 61 of Comparative Example 2, the end having an outward flange 24 by varying the width Wb of the groove bottom portion of the opposite end, by changing the reduction degree those were.
[0107]
　In Example 2 and Comparative Example 4, the width Wb of the groove bottom 55 mm, the values ​​S indicating a reduced degree is 0.00192. In Example 3 and Comparative Example 5, the width Wb of the groove bottom 60 mm, the values ​​S indicating a reduced degree is 0.00179. In Example 4 and Comparative Example 6, the width Wb of the groove bottom 65 mm, the values ​​S indicating a reduced degree is 0.00166. In Example 5 and Comparative Example 7, the width Wb of the groove bottom 70 mm, the values ​​S indicating a reduced degree is 0.00154. In Example 6 and Comparative Example 8, the width Wb of the groove bottom 85 mm, the values ​​S indicating a reduced degree is 0.00115. In Example 7 and Comparative Example 9, the width Wb of the groove bottom 100 mm, the value S indicating a reduced degree is 0.00077. Example 8 and Comparative Example 10, the width Wb of the groove bottom 115 mm, the value S indicating a reduced degree is 0.00038. Example 9 and Comparative Example 11, the width Wb of the groove bottom 120 mm, the value S indicating a reduced degree is 0.00025. In Example 10 and Comparative Example 12, the width Wb of the groove bottom 125 mm, the value S indicating a reduced degree is 0.00013. In Comparative Examples 3 and 13, the width Wb of the groove bottom 130 mm, the value S indicating a reduced degree is zero.
[0108]
　Further, in all Examples 2 to 10 and Comparative Examples 3 to 13, as shown in FIG. 17, four places in the flange portion of the portion corresponding to the groove bottom, two places in the flange portion corresponding to the vertical wall portion, the spot by welding, joining the ends of the pressed bodies 10,61 to another member.
[0109]
　18 and 19, each provided collapse stroke St is 5 mm, 20 mm in the case of the outward flange 24 having a notch at a position corresponding to the press-molded body 10 and the ridge portion having an outward continuous flange 16 It shows the relationship between the value S and the impact energy absorption which indicates the reduction degree of the press-molded body 61.
[0110]
　As shown in FIG. 18, the collapse stroke St is 5 mm, any analytical model 60 and 70 also, large changes in impact energy absorption was observed by the difference of the values ​​S indicating the reduction degree. Also, the analysis model including a comparison of each of the analysis model 60, 70 a value S indicating the same reduced degree, the impact energy absorption of the analysis model 70 including the outward continuous flange 16, an outward flange 24 having a notch It exceeds the impact energy absorption of 60. This result is in pressed bodies 61 having an outward flange 24 having a notch, and stress concentration on the end portion of the ridge portion, due to the distortion of the end portion of the press-molded body 61 is increased.
[0111]
　Further, as shown in FIG. 19, the collapse stroke St is 20 mm, the extent value S of 0.0002 to 0.0018 indicating a reduced degree, the impact energy absorption of the analysis model 70 including the outward continuous flange 16 but it exceeds the impact energy absorption of the analysis model 60 including the outward flange 24 having a notch. This result, by the outward continuous flange 16, together with the stress in addition to the ridge line portion is properly dispersed, the above flare, in order from the end side, due to the buckling at a small buckling pitch occurs. In particular, the value S indicating the reduction degree in the range of 0.00025 to 0.0015, impact energy absorption of the analysis model 70 including the outward continuous flange 16 has a tendency to increase stably.
[0112]
　Figure 20, each analysis model 60, 70 of Example 6 and Comparative Example 3, 8, collapse stroke St is showing how buckling when the 20 mm. As shown in such Figure 20, which has an outward continuous flange 16 to the end, analysis model 70 of Example 6 having a press-molded body 10 having a previously flare T, the occurrence position of the buckling end close to the side, and, buckling pitch is small.
[0113]
　As described above, the press-molded body 10 has an outwardly directed continuous flange 16 to the end, and, if the value S indicating the reduction degree of the above flare is in the range of 0.0002 to 0.0018, from the initial crush stroke over after mid load transmission characteristic at the time of impact load load is increased, it was found that the impact energy absorption is increased. Moreover, by press-molding 10 has a previous flare T, shorter cross-sectional circumference of the press-molded body 10 it can be readily understood that may weight.
[0114]
　However, as the reduction degree of the above flare is small, increases the rise angle of the outward continuous flange 16 continuous with the groove bottom portion, cracks and wrinkles of the flange formed at the end of the ridge portion is likely to occur. Therefore, when considering the formability and production efficiency, it is preferred values ​​S indicating the reduction degree of the above flare is in the range of 0.0005 to 0.0018.
[0115]
(3) Assessment of the reduction in height of the vertical wall portion
　Next, instead of the groove bottom portion of the pressed bodies, the longitudinal wall portion height (width) is reduced with distance from the end having an outward continuous flange were evaluated for impact energy absorption amount at the time it was. Figure 21 shows an analysis model 80, 85 provided with a press-molded body is reduced only vertical wall portion, and an analysis model 90, 95 provided with a press-molded body groove bottom and the vertical wall part was reduced, respectively . Analysis model 80 and 90, provided with an outward continuous flange without notch at a position corresponding to the ridge portion, the analysis model 85 and 95 comprises an outward flange having a notch at a position corresponding to the ridge portion.
[0116]
　These analysis models 80, 85, 90, 95, except that it is reduced groove bottom portion or vertical wall portion, all the same configuration as the above-mentioned analysis model 50, 60, 70. The evaluation method of the impact energy absorption amount is also the same as the evaluation method in the evaluation of (2). However, in order to suppress the collapse of the pressed bodies, the displacement of the non-axial displacement by a rigid wall 29 (see FIG. 13) so as to prevent, it was evaluated by restraining the pressed bodies.
[0117]
　22 and 23 show respectively crush stroke St is 5 mm, 20 mm in the case of the relationship between the value S and the impact energy absorption which indicates the reduction degree of the analysis model 80, 85, 90, 95. The values ​​S indicating the reduction degree in the case where is reduced only vertical walls the width of the groove bottom as constant, indicating a reduced degree of the height of the vertical wall portion. The value indicating the reduction degree in the case that has reduced groove bottom and the vertical wall, respectively S indicates the height and width respectively of the reduced degree of the groove bottom of the vertical wall portion. In other words, even a value S indicating the reduction degree of the analysis model 80 and 90 are the same, cross-sectional circumferential length at the end opposite the end having an outward continuous flange, corresponds to the difference between the width of the groove bottom portion minute to be, will be different.
[0118]
　As shown in FIG. 22 analysis, the collapse stroke St is 5 mm, the impact energy absorption of the analysis model 80, 90 having an outward continuous flange, regardless of the reduction degree, with an outward flange having a notch It was larger than the impact energy absorption of the model 85, 95. Also, the analysis model 80, 90 with an outward continuous flange, large changes in impact energy absorption was observed by the difference of the reduced degree. Further, even in comparison to the analysis model 80, 90 respectively at the same reduction degree, a large difference in impact energy absorption of each analysis model 80 and 90 it was observed.
[0119]
　On the other hand, as shown in FIG. 23, the collapse stroke St is 20 mm, the impact energy absorption of the analysis model 80, 90 having an outward continuous flange, regardless of the reduction degree, with an outward flange having a notch was smaller than the impact energy absorption of the analysis model 85, 95 have. Also, the analysis model 80, 90 with an outward continuous flange, impact energy absorption amount is smaller the larger the reduction degree. The value S indicating a reduced degree except to the extent of about 0.00115, as compared to the impact energy absorption of the analysis model 80 obtained by reducing only the vertical wall, an analysis model was both reduced groove bottom and the vertical wall portion 90 impact energy absorption amount of had become larger.
[0120]
　Note that, in FIGS. 22 and 23, when the value S indicating the reduction degree is 0, impact energy absorption of the analysis model 80 and analysis model 90 having an outward continuous flange should be equal. Similarly, if the value S indicating the reduction degree is 0, impact energy absorption of the analysis model 95 and analysis model 85 having a notch in the flange should be equal. However, as described above, in this evaluation, as the displacement of the non-axial displacement by a rigid wall 29 (see Figure 13) does not occur, indicating since the pressed bodies is restricted, the reduced degree value S is a difference occurs in the impact energy absorption in the case of zero.
[0121]
　Figure 24, each analysis model 80 and 90, crush stroke St is showing how buckling when the 20 mm. As shown in such Figure 24, in any of the analysis model 80, 90, it is understood that the buckling pitch occurring is increased.
[0122]
　As described above, with or without a reduction in the width of the groove bottom, the height of the vertical wall portion, when allowed to shrink with distance from the end having an outward continuous flange has a low load ridge plays is, the impact energy absorption was found to be reduced. Therefore, when obtained by reducing the vertical wall it has been found to not be able to utilize the effect of providing an outward continuous flange on the end of the press-molded body.
[0123]
(4) moldability (Reference) of the outward continuous flange
　as a reference to evaluate the sheet thickness reduction rate at the end of the ridge portion in the press-molded body 10 to be produced by the production method of the above-mentioned press-molding. In Reference Example 1, using a first pad 34-1 and the second pad 34-2, to produce a press-molded body 10 by the manufacturing method of the pressed bodies described above. Further, in Reference Example 2, in place of the first pad and the second pad, except using pad for pressing only the groove bottom under the same conditions as in Reference Example 1 to produce a press-molded body. Furthermore, in Reference Example 3, in place of the first pad and the second pad, except for using simultaneously pressing pad groove bottom and the ridge portion under the same conditions as in Reference Example 1 to produce a press-molded body.
[0124]
　Molding material 33 used has a tensile strength of steel sheet 980MPa grade thickness 1.4mm as measured by tensile test according to JIS Z 2241. Further, in the pressed bodies, the height of the cross-section of substantially groove-type 100 mm, the maximum value of the width of the groove bottom at the end with an outward flange (width Wa) is 148 mm, the minimum value of the width of the groove bottom portion (width wb) is 76 mm, the value S0.0027 indicating a reduced degree of width W of the groove bottom, the width of the outward continuous flange was 14 mm. The curvature radius of the shoulder portion of the punch used was 12 mm.
[0125]
　25 and FIG. 26 is an explanatory diagram showing an analysis result of the sheet thickness reduction rate of the press-formed body of Reference Example 1-3. Figure 25 is a diagram showing an analysis position A of the sheet thickness reduction rate, divided one press-molded body 10 is shown by a center line along the axial direction (x-direction). Figure 26 is a Reference Example 1-3 Analysis results of each of the press-molded body. The analysis, using LS-DYNA is a general purpose analysis software.
[0126]
　Pressed bodies according to Reference Example 2 using the pad for pressing only the groove bottom, of the outward continuous flange, the thickness reduction rate at the position I in the flange which is formed continuously to the end of the ridge line portion 24 It was .8%. In such sheet thickness reduction rate, occurrence of molding defects (cracks) is concerned. Moreover, the press molded body according to Reference Example 2 using the same time pressing pad groove bottom and the ridge portion of the outward continuous flange, the thickness of the level H1 of the flange which is formed continuously to the end of the ridge portion reduction rate was reduced to 11.2%. On the other hand, press-molded body according to Reference Example 3, and the ends of the ridge, the thickness reduction rate of the position H2 at the rising curved portion between the outward continuous flange has a -15.5%, acceptable the occurrence of wrinkles and thickening that exceeds the range is concerned. Thus, the flange is provided at an end portion of the press-molded body when it is outwardly continuous flange, and cracking of the end portion of the flange formed at the end of the ridge portion, the root of the wrinkles of the flange is likely to occur, the conventional , applied to the actual product has not been performed.
[0127]
　In contrast, a press molded body according to Reference Example 1 using the first pad and the second pad of the outward continuous flange 16, the position of the flange which is formed continuously to the end of the ridge portion J1 the plate thickness reduction rate was acceptable value was 15.4%. Further, the end portion of the ridge portion, the plate thickness reduction rate of the position J2 in the rising curved portion between the outward continuous flange 16 is -13.9%, resulting wrinkles and increase meat was in an acceptable range It was. That is, the method for producing a press-molded body described above, in manufacturing the first member 10 as a structural member according to the present embodiment, and cracks at the flange end of the outward continuous flange 16, the teeth at the root of the flange It was found to be our suppressed. Thus, the structural member according to the present embodiment, it is possible to realize by using the high-tensile steel plate.
[0128]
　Having described in detail preferred embodiments of the present invention with reference to the accompanying drawings, the present invention is not limited to such an example. It would be appreciated by those skilled in the relevant field of technology of the present invention, within the scope of the technical idea described in the claims, it is intended to cover various changes in form , also such modifications are intended to fall within the technical scope of the present invention.
[0129]
　For example, in the above embodiments, a description has been given of an example of a structural member made of press-formed bodies obtained by press-molding a steel plate, the material of the structural member is not limited to such an example. For example, the structural member, iron, aluminum, titanium, or may be a press-molded body obtained by press molding a metal plate other than a steel sheet such as stainless steel.
[0130]
　Further, increasing the load transmission characteristics during axial collapse, in order to obtain an effect that the impact energy absorption can be increased may be a metallic structural member molded by a method other than press forming. Furthermore, in order to obtain such effects, it may be made of fiber reinforced resin structural member contains a reinforcing fiber such as a resin material or a carbon fiber.
[0131]
　Further, in the above embodiments, automobiles and trains as application of structural members, chassis or vehicle such as a motorcycle has been illustrated hull of the vessel, the present invention is not limited to such an example. Structural member, if the structure in the axial direction impact load can be loaded, it may be used in structures such as other mechanical or building.
DESCRIPTION OF SYMBOLS
[0132]
　10 first member (automobile body structural member, pressed
　bodies) 11 groove bottom portion
　12a, 12b ridge portions
　13a, 13b vertical wall portion
　14a, 14b curved portions
　15a, 15a flange portion
　16 outward continuous flange
　17 rising curved portion
　18 second member
　23 outward continuous flange
　24 outward flange
　29 rigid walls
　50,60,70,80,90 analysis model
　51, 61 pressed bodies
　100 bonded structure
　T destination flare
　width W groove bottom portion
　Wa outward continuously the width of the groove bottom of the root portion of the flange
　width of the groove bottom positions of any distance from Wb root portion

The scope of the claims
[Claim 1]
　It is formed in an elongated extending in a predetermined direction, and a groove bottom, and two ridge portions continuous in the width direction of both ends of the groove bottom, metallic structural member having a two vertical wall portion further connected to the ridge in,
　the end of the predetermined direction, at least the groove bottom portion, said ridge portion and having an outward continuous flange formed continuously across the vertical wall portion,
　the width of the groove bottom, the outward reduced with increasing distance from the end with a continuous flange, structural member.
[Claim 2]
　Value indicating a reduced degree of the width of the groove bottom portion which is defined by the following formula (1) S (mm -1 ) is a value within the range of 0.0002 to 0.0018 A structure according to claim 1 .
　　S (mm -1 ) = {(Wa-Wb) / Wa} / L ...
(1) Wa: width of the groove bottom at the root portion of the end portion having the outward continuous flange
Wb: width of the groove bottom the groove bottom of the width at the position of an arbitrary distance L from the root portion in the range in which reduced
[Claim 3]
　In the range from the end portion 100mm or more in length with the outward continuous flange, the width of the groove bottom portion is reduced, the structural member according to claim 1 or 2.
[Claim 4]
　Said structural member via said outward continuous flange, resistance spot welding, laser penetration welding, bonding with fillet arc welding or adhesive, or by combination with joining them, it is bonded to another member, according to claim structural member according to any one of 1 to 3.
[Claim 5]
　It said structural member is a tensile strength consisting of high-tensile steel plate of more than 390 MPa, structural member according to any one of claims 1-4.
[Claim 6]
　It said structural member is a structural member for a vehicle, the structural member according to any one of claims 1 to 5.
[Claim 7]
　The vehicle structural member is a floor cross member, side sills, front side member or a floor tunnel brace A structure according to claim 6.