[0001]This invention produces torsion beam applied to metal fatigue is suppressed in torsion beam suspension apparatus for an automobile, to a torsion beam manufacturing method and torsion beam manufacturing apparatus.
　This application, on March 30, 2016, claiming priority on Japanese Patent Application No. 2016-067929 filed in Japanese, which is incorporated herein by reference.
Background technique
[0002]As is well known, torsion beam suspension apparatus have been widely used as a form of automotive suspension systems.
　The torsion beam suspension apparatus: is connected a pair of left and right trailing arms for rotatably supporting the left and right wheels by the torsion beam further comprises a torsion beam assembly pair of left and right spring receiving portions are joined to the left and right ends near the torsion beam; torsion beam and a spring and absorber for connecting the vehicle body; comprising a. Torsion beam via a pivot shaft extending from the left and right of the vehicle body toward the center side, are swingably connected to the vehicle body.
[0003]
　Torsion beam, for example, is formed by plastic working a metal pipe by press molding and hydro forming, in cross section perpendicular to the longitudinal direction of the torsion beam, toward the mounting portion of the trailing arm to a constant shape closed-section portion Te, and it is formed on the closed section of the substantially V-shaped or substantially U-shaped (e.g., see Patent Document 1).
[0004]
　Torsion beam has a constant shape closed cross-section portion having a substantially constant closed cross-section of substantially V-shaped or substantially U-shaped, and a mounting portion connected to the left and right trailing arms, located between the fixed shape closed-section portion and the mounting portion and a shape-changing portion (gradually changing portion) which, when the vehicle body is subjected to an external force from the road surface so as to ensure the roll stiffness of the vehicle body by torsional rigidity mainly torsion beam.
[0005]
　On the other hand, even torsion beam had sufficient roll stiffness, torsion beam, for receiving a variety of external force from the road surface through the wheels and trailing arm, complex stress distribution due to such external force is generated and, metal fatigue is likely to progress. The metal fatigue, for example, significantly likely to occur at the connection portion near between shape-changing portion and a constant shape closed-section portion.
[0006]
　Therefore, even when subjected to various external forces from the road surface, it is necessary to suppress the development of metal fatigue, various techniques have been developed to suppress such metal fatigue (e.g., Patent Documents 2 and 3 , reference 4).
[0007]
　The technique described in Patent Document 2, after press forming torsion beam, quenching, tempering, performing shot peening, by curing the outer surface of the torsion beam, improve the fatigue properties of the torsion beam.
[0008]
　The technique described in Patent Document 3, by using a steel pipe surface hardness is high after the heat treatment, to improve the surface hardness of the torsion beam, improve the fatigue properties of the torsion beam.
[0009]
　The technique described in Patent Document 4 imparts that a tensile stress applying pressure toward the outside from the inside of the steel pipe by hydroforming, as a result, to improve the fatigue properties by reducing the residual stress of the torsion beam.
CITATION
Patent Document
[0010]
Patent Document 1: Japanese Patent 2011-635 JP
Patent Document 2: Japanese Patent 2001-123227 JP
Patent Document 3: Japanese Patent 2008-063656 JP
Patent Document 4: Japanese Patent 2013-091433 No.
Summary of the Invention
Problems that the Invention is to Solve
[0011]
　However, to improve the fatigue properties of the torsion beam by applying the technique described in Patent Documents 2 to 4, on which not necessarily easy, there is a problem of initial costs and production running costs such as equipment investment increases . Therefore, the torsion beam manufacturing technology capable of producing a torsion beam fatigue characteristics excellent efficiently is desired.
[0012]
　The present invention has been made in view of such circumstances, that is capable of producing excellent torsion beam fatigue properties efficiently, and to provide the torsion beam manufacturing method and torsion beam manufacturing apparatus.
Means for Solving the Problems
[0013]
　In order to solve the above problems, the present invention proposes the following means.
(1) torsion beam manufacturing method according to an embodiment of the present invention, a constant shape closed cross-section portion is a closed cross-section of substantially V-shaped or substantially U-shaped at any position of the cross section perpendicular to the longitudinal direction longitudinally, a method of manufacturing a torsion beam having a shape changing portion having a connection region having a closed section of the certain shaped closed continuous to face and the closed section different shapes, the predetermined shape closed-section portion and said for at least the connection region of the torsion beam material shape change portion is formed, a step tensile obtain the torsion beam by adding a tensile force along the longitudinal direction.
　According to the torsion beam manufacturing method according to this aspect, tensile for applying a tensile force to at least the connection region in step, it is possible to reduce or eliminate the residual stress remaining.
　As a result, it is possible to produce an excellent torsion beam fatigue properties. Moreover, since it does not require post-heat treatment or the like, it can be efficiently produced.
[0014]
(2) In the torsion beam method according to the above (1), wherein the tensile step, and the inside of the outer part along the longitudinal direction than the connection region is supported by the inner support member, the outer portion the outer locking member in a state in which to engage with the outside, by moving the inner support member and the outer engaging member in a direction away from said predetermined shape closed-section portion, may be added to the tension force.
　In this case, tensile step, in terms of supporting the outer portion of the torsion beam material in the inner support member, since applying a tensile force locked so the outer locking member on the outside of the outer portion, the Dosotokata portion it can provide easily pulling force while suppressing deformation.
[0015]
(3) In the torsion beam manufacturing method described in the above (2), the tensile step, supporting the outside of the connection area outside the support member, and the movement in the same direction of the inner support member and the outer engaging member synchronously, it may move the outer support member.
　In this case, the outer support member, to move in synchronism with the movement of the inner support member and the outer engaging member, it does not inhibit the extension of the torsion beam material due to tension. Therefore, since the tensile force can be applied to ensure the torsion beam material, it is possible to reduce or remove reliably residual stress.
[0016]
(4) In the torsion beam method according to the above (1), wherein the tensile step, the torsion beam material between both ends by making relatively spaced along said longitudinal, length of the torsion beam material the pulling force it may be added over.
　In this case, for pulling the torsion beam material longitudinally outward over its entire length, the residual stress without leakage can be reduced or removed.
[0017]
(5) In the torsion beam manufacturing method according to any one of the above (1) to (4), in the tension step, a distortion of 1% or more in the longitudinal direction at least with respect to the connection region of the torsion beam material it may be applied.
　In this case, it is possible to impart sufficient tensile strength to cause eliminate or reduce residual stresses in the torsion beam material.
[0018]
(6) In the torsion beam manufacturing method according to any one of the above (1) to (5), prior to the pulling step may include a pressing step of the blank tube is pressed to obtain the torsion beam material .
　In this case, at the time after the pressing step, there remains a residual stress in the torsion beam material can be followed by pulling process, to remove it.
[0019]
(7) torsion beam manufacturing apparatus according to an embodiment of the present invention, a constant shape closed cross-section portion is a closed cross-section of substantially V-shaped or substantially U-shaped at any position of the cross section perpendicular to the longitudinal direction longitudinally, an apparatus for manufacturing a torsion beam having a shape changing portion having a connection region having a closed section of the certain shaped closed sectional in continuous with and the closed section shape different from said predetermined shape closed-section portion and said of the torsion beam material shape change portion is formed, retaining the portion of the on one side than the connection area when viewed along the longitudinal direction of the torsion beam material, and a portion on the other side of the connection region a pair of retaining mechanism; a first drive mechanism that relatively spaced between the respective holding mechanism; comprises.
　According to the torsion beam manufacturing apparatus according to this embodiment, the pair of holding mechanism and the first driving mechanism, the addition of longitudinal pulling force to at least the connection region of the torsion beam material remaining in the torsion beam material residual stresses are capable of reducing or removing.
　As a result, it is possible to produce an excellent torsion beam fatigue properties. Moreover, since it does not require post-heat treatment, it is possible to efficiently manufacture.
[0020]
In the torsion beam manufacturing apparatus according to (8) above (7), wherein the holding mechanism may hold both ends of the torsion beam material.
　In this case, since the pull holding both ends of the torsion beam material by the pair of holding mechanisms can impart a tensile force over the entire length of the torsion beam material. Therefore, it is possible to reduce or remove residual stress without omission over the entire length of the torsion beam material.
[0021]
(9) In the torsion beam manufacturing apparatus according to (8), said predetermined shape closed-section portion and the movable mold and having a shape corresponding to the shape changing portion; the certain shape closed-section portion and said shape to said torsion beam material to blank tube before applying the change portion, a second drive mechanism for pressing the movable mold; it may further comprise a.
　In this case, the movable mold by a second driving mechanism by pressing the blank tube, it is possible to obtain a torsion beam material having a predetermined shape closed cross-section portion and a shape changing part.
[0022]
(10) In the torsion beam manufacturing apparatus according to (7), at least one of the respective holding mechanism, an inner support member which is inserted inside the shape-changing portion; engaging on the outside of the shape-changing portion an outer locking member which, may be provided.
　In this case, in terms of supporting the inside of the shape changing portion of the torsion beam material inside the supporting member, it is possible added pulling force to outer locking member to engage with the outside of the shape changing portion, deformation of the shape-changing portion it can provide easily pulling force while suppressing a.
[0023]
(11) In the torsion beam manufacturing apparatus according to the above (10), said predetermined shape closed-section portion and the movable mold and having a shape corresponding to the shape changing portion; the certain shape closed-section portion and said shape to said torsion beam material to blank tube before applying the change portion, a second drive mechanism for pressing the movable mold; it may further comprise a.
　In this case, the movable mold by a second driving mechanism by pressing the blank tube, it is possible to obtain a torsion beam material having a predetermined shape closed cross-section portion and a shape changing part.
[0024]
(12) In the torsion beam manufacturing apparatus according to (11), may be employed the following configuration: the movable mold, and the movable mold body having a shape corresponding to at least the predetermined shape closed-section portion , has a shape corresponding to at least the shape-changing portion and said movable mold-defining member movable mold end portion provided freely away from the unit, the movable mold end than the movable mold body portion It comprises a third drive mechanism to separate the parts, the; the movable mold ends, also serves as the outer locking member.
　In this case, with respect to base tube which is pressed by the movable die, with give a shape corresponding to at least a predetermined shape closed-section portion by the movable mold body portion, a shape corresponding to at least the shape changing part by the movable mold ends give. Such inserts the inner support member to the inner side of the shape changing portion of the torsion beam material obtained in, also in a state in which locking the movable mold ends outside of the shape changing portion, applying a tensile force to the torsion beam material. According to this arrangement, the movable die end, because also serves as the outer locking member, without transferring the torsion beam material raw tube and the obtained by pressing the other device, pulling as it continues it is possible to apply a force.
[0025]
In the torsion beam manufacturing apparatus according to (13) above (12), said third drive mechanism may be a cam which is inserted into a gap between the movable mold body part and the movable mold ends.
　In this case, first, processing in the torsion beam material by pressing the raw tube by the movable mold body part and the movable mold ends. Subsequently, by pushing the gap cam, push the gap between the movable mold main body and the movable mold ends. Then, to move in a direction in which the movable mold ends from the movable mold body portion away, by applying a tensile force to the torsion beam material, it is possible to reduce or remove residual stress.
[0026]
(14) (7) In the torsion beam manufacturing apparatus according to any one of - (13), may be employed the following configuration: further comprising a support die for supporting the torsion beam material; the supporting metal types, the torsion beam material, a support mold body portion that supports the portion including the predetermined shape closed cross-section portion, and rotatably provided apart from the said support die body portion, at least the shape-changing portion and a supporting mold end portion supporting.
　In this case, when applying a tensile force to the torsion beam material, since the supporting mold end is freely away from the support die main body, it does not inhibit the extension of the torsion beam material due to tension. Therefore, since the tensile force can be applied to ensure the torsion beam material, it is possible to reduce or remove reliably residual stress.
[0027]
(15) (7) In the torsion beam manufacturing apparatus according to any one of - (14), may be employed the following configuration: further comprising a control unit for controlling said first driving mechanism; the control unit, the first by operating the driving mechanism to impart distortion of 1% or more in the longitudinal direction at least with respect to the connection region of the torsion beam material.
　In this case, it is possible to impart sufficient tensile strength to cause eliminate or reduce residual stresses in the torsion beam material.
[0028]
　The present invention may employ the following aspects in addition to the above aspects.
(A) Another aspect of the present invention, a pair of left and right arms used torsion beam suspension apparatus is connected to both ends in the longitudinal direction, the longitudinal direction perpendicular to the cross section of the front and rear ends in the longitudinal direction of the vehicle body wherein between the constant shape closed-section portion and attached closed cross-section portion which substantially is constant closed cross section of the substantially V-shaped or substantially U-shaped projecting upper or lower side of the certain shaped closed sectional attached closed-section portion a torsion beam method of manufacturing the torsion beam having a shape changing portion being positioned, forming a torsion beam material having a metallic material tube is pressed with the predetermined shape closed-section portion and said shape changing portion between the a pressing step, the tensile process for pulling a connection part for connecting at least the predetermined shape closed-section portion and the shape variation of the torsion beam material longitudinally Equipped with a.
[0029]
　According to the torsion beam manufacturing method according to this embodiment, the pressing step of forming the torsion beam material having a metallic material tube is pressed constant shape closed-section portion and the shape change portion, at least a certain shape closed-section portion of the torsion beam material since the connecting portion connecting the shape change portion and a tensile processing step of pulling in the longitudinal direction, tensile residual stress from the connection portion can be reduced or removed.
　As a result, it is possible to produce a torsion beam that has fatigue properties superior efficiently.
[0030]
　In this specification, certain shape and is closed sectional, substantially constant closed section (e.g., a valley of the wall portion constituting the concave side of the substantially V-shaped or substantially U-shaped in a substantially V-shaped or substantially U-shaped part (bottom)) refers to the moiety that is formed continuously along the longitudinal direction. Note that up to the shape changing portion valleys of the wall portion constituting the concave side of the substantially V-shaped or substantially U-shaped (bottom) is gradually shallower continuously, be partially irregularities are formed It included in the constant shape closed cross-section portion.
[0031]
　The portion in this specification, the shape changing part, which forms the trough portion of the wall portion constituting the concave side of the substantially V-shaped or substantially U-shaped (bottom) is gradually shallow is formed continuously you say. Incidentally, in the middle of the shape-changing portion valley (bottom) may be formed partially shallow become part.
[0032]
　Further, in this specification, the mounting closed cross-section portion, is positioned longitudinally outward of the shape-changing portion (the vehicle width direction outer side), the recess having a substantially V-shaped or substantially U-shaped is formed say no part.
[0033]
　Further, in this specification, the connecting portion connecting the fixed shape closed cross-section portion and a shape changing part, refers to a portion including the boundary of the predetermined shape closed-section portion and a shape changing part, the longitudinal direction at a constant shape the closed-section portion to form the valleys of the wall portion constituting the concave side of the substantially V-shaped or substantially U-shape formed along the (bottom), inclined relative to gradually shallower be longitudinally continues at radius variations in is a moiety containing the site to be migrated. The range of the connecting portion can be arbitrarily set based on the distribution and the like of the tensile residual stress.
[0034]
(B) a torsion beam method according to the (a), in the tension process, the torsion beam radius variations in the shape changing portion is inserted the inner support member inwardly of the shape change of the material the support member engages, pulling the connecting part in the longitudinal direction.
[0035]
　According to the torsion beam manufacturing method, tensile in process step, engages a shape-changing portion support member to the shape changing portion is inserted the inner support member inwardly of the shape change of the torsion beam material, the longitudinal connecting portions since tensile direction, it is possible to reliably suppress the deformation of the shape-changing portion while pulling easily longitudinally outward the connecting portion of the torsion beam material.
　As a result, it is possible to produce a torsion beam that has fatigue properties superior efficiently.
[0036]
A torsion beam method according to (c) above (a), in the tension process, retains the mount closed cross-section portion of the torsion beam material, pulling the connecting part in the longitudinal direction.
[0037]
　According to the torsion beam manufacturing method, the elongation process step, while holding the mounting closed cross-section portion of the torsion beam material, since the tensile connecting portion in the longitudinal direction, it is possible to pull longitudinally outwardly along the entire length of the torsion beam material .
　As a result, it is possible to produce a torsion beam that has fatigue properties superior efficiently.
[0038]
(D) Yet another aspect of the present invention, a pair of left and right arms used torsion beam suspension apparatus is connected to both ends in the longitudinal direction, front and rear cross-section perpendicular to the longitudinal direction in the longitudinal direction of the vehicle body wherein a substantially constant closed cross section has been a constant shape closed-section portion and attached closed cross-section portion and the fixed shape closed-section portion mounting closed section of the substantially V-shaped or substantially U-shaped while protrudes above or below the a torsion beam manufacturing apparatus for manufacturing the torsion beam having a shape changing unit which is located between the parts, and the shape change outer side holding member having an outer retaining shape portion formed complementarily to the shape changing portion advancing and retracting the provided in the mold wherein the shape changing part and the shape-changing portion support member for supporting engaged from the longitudinal inward, the mounting closed-section portion holding member in the longitudinal direction of the torsion beam material Comprising a that drive unit, and a control unit, said control unit, said after forming the torsion beam material, the while holding the shape changing part by the inner support member and the shape change outer side holding member is configured to the shape-changing portion support member is moved longitudinally outwardly of the torsion beam material.
[0039]
　According to the torsion beam device, a shape change outer side holding member having an outer retaining shape portion which is complementarily formed to the shape changing portion, provided on the mold engages the radius variations from the longitudinal inner by the support to the shape changing portion support member while holding the shape changing portion, since the connecting portion by moving the shape-changing portion support member in the longitudinal direction outwardly of the torsion beam material pulling longitudinally, shape change unit is deformed it is possible to stably pull processed prevented from.
　As a result, it is possible to produce a torsion beam that has fatigue properties superior efficiently.
[0040]
(E) still further aspect of the present invention, a pair of left and right arms used torsion beam suspension apparatus is connected to both ends in the longitudinal direction, front and rear cross-section perpendicular to the longitudinal direction in the longitudinal direction of the vehicle body wherein a substantially constant closed cross section has been a constant shape closed-section portion and attached closed cross-section portion and the fixed shape closed-section portion mounting closed section of the substantially V-shaped or substantially U-shaped while protrudes above or below the a torsion beam manufacturing apparatus for manufacturing the torsion beam having a is the radius variations located between the parts, and the mounting closed cross-section portion holding member which holds the mounting closed-section portion, said mounting closed-section portion holding member torsion beam comprising a driving unit for advancing and retracting in the longitudinal direction of the material, and a control unit, wherein, in a state where the attachment closed-section portion holding member is holding the mounting closed-section portion, the torsion bi It is configured to pull the beam material in the longitudinal direction.
[0041]
　According to the torsion beam device, to hold the mounting closed cross-section portion of the torsion beam material, since the tensile connecting portion in the longitudinal direction, it is possible to pull longitudinally outwardly along the entire length of the torsion beam material.
　As a result, it is possible to produce a torsion beam that has fatigue properties superior efficiently.
[0042]
(F) further aspect of the present invention, a pair of left and right arms used torsion beam suspension apparatus is connected to both ends in the longitudinal direction, front and rear cross-section perpendicular to the longitudinal direction in the longitudinal direction of the vehicle body wherein a substantially constant closed cross section has been a constant shape closed-section portion and attached closed cross-section portion and the fixed shape closed-section portion mounting closed section of the substantially V-shaped or substantially U-shaped while protrudes above or below the a torsion beam manufacturing apparatus for manufacturing the torsion beam having a shape changing unit which is located between the parts, forming a torsion beam material having a metallic material tube is pressed with the predetermined shape closed-section portion and the radius variations mold and the shape changing portion support member for supporting engaged to provided in the mold wherein the shape changing portion from the longitudinal inward, wherein the shape changing portion supported is provided in the mold to A shape-changing portion supporting member driving unit for reciprocating the member in the longitudinal direction, the set to be inserted inwardly of the radius variations, inward to retain said shape changing unit in cooperation with the shape-changing portion support member comprising a support member, and a control unit, said control unit, said torsion beam material after molding, said shape-changing portion supporting member and said inner said while holding the shape change portion by the supporting member shape change unit is configured to move the support member in the longitudinal direction outwardly of said torsion beam material.
[0043]
　According to the torsion beam manufacturing apparatus, the control unit, after forming the torsion beam material a metal material tube is pressed in a state where the shape change portion support member and the inner support member holding the shape changing portion cooperate since tensile torsion beam material longitudinally outwardly by the drive unit, the residual tensile stress from the connection portion can be reduced or removed.
　As a result, it is possible to produce a torsion beam that has fatigue properties superior efficiently.
[0044]
(G) torsion beam suspension apparatus a pair of right and left arms used is connected to both ends in the longitudinal direction, protruding between the front and rear ends to the upper or lower side in the longitudinal direction of the cross-section body that is perpendicular to the longitudinal direction shape which is located between the substantially V-shaped or constant shape closed-section portion and attached closed cross-section portion which substantially is constant closed cross section substantially U-shaped and the constant shape closed-section portion and the mounting closed-section portion to a torsion beam manufacturing apparatus for manufacturing the torsion beam having a change portion, and a mold for molding a torsion beam material having a metallic material tube is pressed with the predetermined shape closed-section portion and wherein the shape changing part, the mold a shape-changing portion support member provided support engages said shape changing unit from the longitudinal inward, forward and backward the shape-changing portion support member provided in the mold in the longitudinal direction A shape-changing portion supporting member driving unit that is capable of being inserted into the inside of the shape-changing portion, and a inner support member for holding the shape change unit in cooperation with the shape-changing portion support member, the drive unit is constituted by a cam mechanism operated by the stroke when the mold for molding the torsion beam material.
[0045]
　According to the torsion beam manufacturing apparatus, after forming the torsion beam material a metal material tube is pressed, the cam mechanism is actuated by the stroke in molding the torsion beam material, the shape-changing portion support member and the inner support member since pulling longitudinally outwardly by the drive unit a torsion beam material while holding the shape changing portion cooperate residual tensile stress from the connection portion can be reduced or removed.
　As a result, it is possible to produce a torsion beam that has fatigue properties superior efficiently.
[0046]
(H) a torsion beam manufacturing apparatus according to any one of the above (d) ~ (g), when the tensile said torsion beam material longitudinally, shape change absorbing means is displaced along with the longitudinal direction of the shape change It is equipped with a.
[0047]
　According to the torsion beam manufacturing apparatus, when pulling the torsion beam material in the longitudinal direction, is provided with the shape change absorbing means is displaced along with the longitudinal direction of the shape change, there in case of a large longitudinal center side of the shape of the torsion beam also, it is possible to easily pull process.
　Further, torsion beam material upon pulling process to suppress that hurt, efficient residual stress can be reduced.
Effect of the invention
[0048]
　According to the torsion beam manufacturing method and torsion beam manufacturing apparatus according to the above embodiment, it is possible to produce an excellent torsion beam fatigue properties efficiently.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049]
FIG. 1 is a perspective view illustrating a schematic configuration of a torsion beam type rear suspension apparatus according to a first embodiment of the present invention.
[Figure 2] A diagram illustrating a schematic configuration of a torsion beam assembly according to the embodiment is a perspective view from below.
3 is a perspective view illustrating a schematic configuration of a torsion beam according to the embodiment.
4 is a perspective view illustrating a schematic configuration of the shape changing portion of the torsion beam according to the embodiment.
[Figure 5A] A diagram showing a schematic configuration of a torsion beam according to the embodiment, a closed cross-section view when viewed in arrow VA-VA in FIG.
[Figure 5B] A diagram showing a schematic configuration of a torsion beam according to the embodiment, a closed cross-section view when viewed in arrow VB-VB of FIG.
[Figure 5C] A diagram showing a schematic configuration of a torsion beam according to the embodiment, a closed cross-section view when viewed in arrow VC-VC in FIG.
6 is a flowchart illustrating an example of a torsion beam of the manufacturing process according to the embodiment.
7 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus according to the embodiment.
[Figure 8] A diagram for explaining along the flow of the respective pulling process 8 (A) ~ FIG 8 (E) in the torsion beam manufacturing process according to the embodiment, which corresponds to the A portion in FIG. 7 it is a diagram.
[9] for explaining the effect of the tensile process in the embodiment, a diagram showing the stress distribution in the closed cross section corresponding to FIG. 5A, shows the stress distribution before pulling process FIG. 9 (A), the Figure 9 (B) shows the stress distribution after stretching treatment.
[Figure 10] for explaining the effect of the tensile process in the embodiment, a diagram showing the stress distribution in the closed cross section corresponding to FIG. 5B, FIG. 10 (A) shows the stress distribution before the tensile process, Figure 10 (B) shows the stress distribution after stretching treatment.
[Figure 11] for explaining the effect of the tensile process in the embodiment, a diagram showing the stress distribution in the closed cross section corresponding to FIG. 5C, FIG. 11 the tensile pretreatment stress distribution (A), FIG. 11 (B) shows the stress distribution after stretching treatment.
12 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus according to a second embodiment of the present invention.
[Figure 13] A drawing will be described along the flow of the carrying out manufacturing steps of the torsion beam according to a 13 (A) ~ FIG 13 (D), is a view corresponding to portion B of FIG. 12.
14 is a flowchart for explaining a manufacturing process of the torsion beam according to a third embodiment of the present invention.
15 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus according to the embodiment.
[Figure 16] A drawing will be described along the flow of the exemplary figure manufacturing steps of the torsion beam according to a 16 (A) ~ FIG 16 (E), is a view corresponding to section C of FIG. 15.
17 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus according to a fourth embodiment of the present invention.
[Figure 18] A drawing will be described along the flow of the exemplary figure manufacturing steps of the torsion beam according to a 18 (A) ~ FIG 18 (E), is a view corresponding to part D of Figure 17.
19 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus according to a fifth embodiment of the present invention.
[Figure 20] A drawing will be described along the flow of FIG respective manufacturing steps of the torsion beam according to the embodiment 20 (A) ~ FIG 20 (E), it is a view corresponding to part E of FIG. 19.
The modification of FIG. 21 the present invention there is provided a graph showing a case of application to the second embodiment, showing a portion corresponding to the G portion of FIG. 12. Figure 21 (A) indicates a step of grasping by forming a step portion in the tube end, FIG. 21 (B) indicates a step of pulling the pipe end after grasping.
DESCRIPTION OF THE INVENTION
[0050]

　Hereinafter, with reference to FIG. 11 (B) from FIG. 1, will be described first embodiment of the present invention.
　Figure 1 is a diagram showing a schematic configuration of a torsion beam type rear suspension apparatus according to the present embodiment (torsion beam suspension apparatus), reference numeral 1 denotes a torsion beam type rear suspension apparatus, reference numeral 2 denotes a torsion beam assembly, reference numeral 10 It shows a torsion beam. Reference numeral F shown in FIG. 1 shows the front of the vehicle (not shown) that the torsion beam type rear suspension apparatus 1 is mounted, reference numeral R represents the rear.
[0051]
　Torsion beam type rear suspension apparatus 1, as shown in FIG. 1, includes a torsion beam assembly 2, a spring 3 and absorber and 4 for connecting the torsion beam assembly 2 and the vehicle body (not shown), a.
[0052]
　The torsion beam assembly 2, the left and right wheels WL, to support the by the left and right pair of trailing arms 5 WR, pivot shaft JL extending slightly toward the front center side from the left and right of the vehicle body, is connected to the vehicle body via the JR ing. The torsion beam assembly 2 is configured to be swingable with respect to the vehicle body.
[0053]
　The torsion beam assembly 2, as shown in FIG. 2, for example, a pair of left and right trailing arms (arm) 5, and torsion beam 10 for connecting the these trailing arm 5, a pair of left and right spring receiver for supporting the spring 3 and a 3A. Further, one end side of the absorber 4 is a buffer device is connected to a buffer receiving portion (not shown).
　In the present embodiment, the torsion beam 10, FIG. 1, as shown in FIG. 2, has a closed cross section of the substantially V-shape is convex upward.
[0054]
　Trailing arm 5, as shown in FIG. 2, for example, a pivot mounting member supported and the trailing arm body 5A, connected to the front end of the trailing arm body 5A in the vehicle body via a pivot shaft J and 5F, is coupled to the rear end wheel WL of the trailing arm body 5A, and a wheel mounting member 5R supporting the WR.
[0055]
　Spring receiver 3A is arranged on the opposite side of the pivot mounting members 5F sandwiched between the torsion beam 10, one end of the spring 3 is mounted. Load received from the road surface is, the wheels WL, WR, trailing arm 5, and is transmitted to the vehicle via a spring 3.
[0056]
　Referring to FIGS 5C, described torsion beam 10 according to this embodiment.
　Figure 3 is a perspective view illustrating a schematic configuration of the torsion beam 10 according to this embodiment. Figure 4 is a perspective view illustrating the shape changing part schematic of the vicinity of the torsion beam 10. 5A, 5B, 5C is a cross-sectional view showing a torsion beam 10, FIG. 5A shows a cross-sectional view at arrow VA-VA in FIG. 4, FIG. 5B is in arrow VB-VB in FIG. 4 shows a cross-sectional view, Figure 5C is a cross sectional view taken along the plane arrow VC-VC in FIG.
[0057]
　Torsion beam 10, as shown in FIGS. 3 and 4, a constant shape closed-section portion 11 having a closed cross section of constant shape of the longitudinal center side is formed substantially V-shaped, the shape changing portion 12, attached close the cross section 13 has a closed cross section of substantially elliptical shape are formed at the outer end of the attachment closed cross-section portion 13, and a mounting portion 14 trailing arm 5 is attached.
[0058]
　Constant shape closed-section portion 11, when viewed in cross section perpendicular to the torsion beam 10 in the longitudinal direction, forming a substantially uniform closed cross section of the substantially V-shaped or substantially U-shaped in succession along the longitudinal direction is a portion that is. Note that in certain shape closed portion 11, the valley portions of the wall portion constituting the concave side of the substantially V-shaped or substantially U-shaped (bottom), it may be partially irregularities formed.
[0059]
　Shape changing unit 12, a valley portion of the wall portion constituting the concave side of the substantially V-shaped or substantially U-shaped depth (bottom), gradually shallower toward the longitudinal outside (vehicle width direction outside) it is made part. Incidentally, in the middle of the shape changing portion 12, portions of valleys (bottom) is further shallower may be partially formed.
[0060]
　Mounting closed-section portion 13 is disposed longitudinally outward of the shape-changing portion 12 (the vehicle width direction outside), refers to a moiety that is concave having a substantially V-shaped or substantially U-shaped not formed.
[0061]
　Constant shape closed cross-section portion 11, the shape changing portion 12, the attachment closed cross-section portion 13, mounting portions 14 are disposed in this order toward both ends from the longitudinal center of the torsion beam 10. Then, the constant shape closed-section portion 11 and the shape-changing portion 12 are connected by the connecting portion 12A shown in FIG.
[0062]
　Constant shape closed-section portion 11, as shown in FIGS. 3 and 4, are located in the central longitudinal direction of the torsion beam 10 is connected to each shape changing portion 12 at its longitudinal ends.
　Constant shape closed-section portion 11, together with the cross section perpendicular to the longitudinal direction of the torsion beam 10 is formed in a predetermined shape of the substantially V-shaped, in this embodiment, for example, it has a shape which is symmetrical in the longitudinal direction of the vehicle body there.
[0063]
　Cross-section of a shape closed-section portion 11 is, for example, in the closed section of the substantially V-shape shown in FIG. 5A, the first wall portion S110A forming a concave side inner surface, a second wall portion S120A forming the convex side outer surface, these and a two folded wall portion S130A that bulges outward in the closed section together with the connection between the first wall portion S110A and second wall portions S120A of both ends. Circumferential center portion of the first wall portion S110A is valley of the concave side of the substantially V-shaped and (bottom) S111A in certain shapes the closed-section portion 11.
　Then, the first wall portion S110A and the second wall portion S120A, are in contact with each other via the contact portion S150A.
[0064]
　Each folded-back wall portions S130A is a range indicated by an arrow in FIG. 5A, each are formed between the first wall portion side turn point a and the second wall portion side turn point b.
　The first wall portion folding point a is a connection point between the edge of the edge and the folded wall portion S130A of the first wall portion S110A. The second wall portion side turn point b is a connection point between the edge of the edge and the folded wall portion S130A of the second wall portion S120A.
[0065]
　Connecting portion 12A shown in FIG. 4 (connection area) is connected between the constant shape closed-section portion 11 and the shape-changing portion 12 is a portion including the boundary of the predetermined shape closed-section portion 11 and the shape-changing portion 12. That is, the connecting portion 12A, as shown in FIG. 4, a constant shape is the boundary between the closed-section portion 11 and a shape changing part 12 from the cross S12A, longitudinal middle position of the shape-changing portion 12 (e.g., the shape changing portion 12 is a portion extending valley portion of the wall portion constituting the concave side of the substantially V-shaped or substantially U-shaped (bottom) is gradually shallower, the cross section S12C to migrate to form inclined with respect to the longitudinal position) in . The range of the connection portion 12A may be arbitrarily set based on the distribution and the like of the tensile residual stress.
[0066]
　Sectional S12B included in the connection part 12A, for example, as shown in FIG. 5B, a first wall portion S110B forming a concave side inner surface at the closed section of the substantially V-shaped, the second wall portion forming the convex side outer surface in the closed section and S120b, and a two folded wall portion S130B that bulges outward in the closed section together with the connecting across these first wall portion S110B and the second wall portion S120b. Also, the circumferential center portion of the first wall portion S110B is the valley of the concave side of the substantially V-shaped (bottom) S111B at connection 12A.
　Then, between the first wall portion S110B and the second wall portion S120b, the hollow portion 150B is formed.
[0067]
　Each folded-back wall portions S130B is a range indicated by an arrow in Figure 5B, are respectively formed between the first wall portion side turn point a1 and the second wall portion side turn point b1.
　The first wall portion folding point a1 is a connection point between the edge of the edge and the folded wall portion S130B of the first wall portion S110B. The second wall portion folding point b1 is a connection point between the edge of the edge and the folded wall portion S130B of the second wall portion S120b.
[0068]
　As shown in FIG. 4, the shape changing portion 12, the longitudinal inboard torsion beam 10 is connected to a constant shape closed cross-section portion 11, towards the longitudinal outer is connected to the mounting closed cross-section portion 13.
　The shape changing portion 12, the shape of the closed cross section perpendicular to the longitudinal direction of the torsion beam 10 is adapted to shift gradually towards the fixed shape closed cross-section portion 11 to the mounting closed cross-section portion 13.
[0069]
　Shape changing unit 12, for example, as shown in FIG. 5C, a first wall portion S110C forming a concave side inner surface at the closed section of the substantially V-shaped, and the second wall portion S120C forming the convex side outer surface in the closed section , and a two folded wall portion S130C that bulges outward in the closed section together with the connection between the first wall portion S110C and second wall portions S120C of both ends. Also, the circumferential center portion of the first wall portion S110C is the valley of the concave side of the substantially V-shaped (bottom) S111c.
　Then, between the first wall portion S110C and the second wall portion S120c, the hollow portion 150C is formed.
[0070]
　Folded wall portion S130C is a range indicated by an arrow in FIG. 5C, it is respectively formed between the first wall portion side turn point a2 and the second wall portion side turn point b2.
　The first wall portion folding point a2 is a connecting point between the edge of the edge and the folded wall portion S130C of the first wall portion S110c. The second wall portion folding point b2 is a connection point between the edge of the edge and the folded wall portion S130C second wall portion S120c.
[0071]
　As shown in FIG. 4, the attachment closed cross-section portion 13, for example, the longitudinal direction outward of the shape-changing portion 12 is located in (the vehicle width direction outside), the concave substantially V-shaped or substantially U-shaped It has a closed cross section of substantially elliptical shape without.
[0072]
　Next, referring to FIG. 6, illustrating an example of a manufacturing process of the torsion beam 10 according to the first embodiment. Figure 6 is a flow chart showing an example of a manufacturing process of the torsion beam 10.
[0073]
　Referring to FIG 6, a description will be given of a manufacturing process of the torsion beam 10.
(1) preparing a metal material tube (step S101).
　The metal material pipe to be prepared, for example, it is possible to wall thickness used uniform Tubular.
(2) Next, in the pressing step, pressing a metal material tube (step S102).
　Forming a torsion beam material by pressing a metal material tube. Press working, it is possible to use a known press machine.
By pressing in (3) Step S102, the torsion beam material is formed (step S103). Torsion beam material has a certain shape closed cross-section portion, the shape changing part, and a mounting closed cross-section portion, connecting portions for connecting the fixed shape closed cross-section portion and the shape-changing portion (connection area) is formed.
(4) Then, the tensile process, pulling handle torsion beam material (step S104). This tension process, the torsion beam material, by applying a distortion of 1% or more in the axial direction, certainly, it is possible to release the residual stress in the front and back surfaces in the thickness direction. The tensile force in the longitudinal direction of the torsion beam material, in particular may be added only to the portion to be reduce residual stress, but who was added over the entire length as in this embodiment, no leak of residual stresses as a whole more preferable in that it can be reduced.
(5) by pulling handle torsion beam material in step S104, the torsion beam 10 is formed (step S105).
[0074]
　Next, with reference to FIG. 7 will be described a schematic configuration of a torsion beam manufacturing apparatus according to the first embodiment. Figure 7 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus 100 according to the first embodiment.
[0075]
　The torsion beam manufacturing apparatus 100 includes a torsion beam element supporting stand 110 for mounting the torsion beam material W10, it is provided with a two tensile processing unit 120 to pull the torsion beam material W10 in its longitudinal direction, control unit (not shown).
[0076]
　Torsion beam material supporting table 110, it has been recesses 110U is formed corresponding to the outer shape of the torsion beam material W10 at the top, a torsion beam material W10 placed on the recessed portion 110U stably supported.
　In the description of the torsion beam material W10 below, to distinguish them from the torsion beam 10, corresponding to each portion of constant shape closed cross-section portion 11, the shape changing portion 12, the attachment closed cross-section portion 13, the mounting portion 14 of the torsion beam 10 sites the respectively predetermined shape closed cross-section portion 11W, the shape changing portion 12W, mounting closed cross-section portion 13W, instead attachment portion 14W and the sign will be described.
[0077]
　Tensile processing unit 120, as shown in FIG. 7, the mounting closed cross-section portion holding member 121 for holding the mounting closed-section portion 13W of the torsion beam material W10, torsion beam material W10 mounting closed cross-section portion holding member 121 along the arrow T120 a hydraulic cylinder (driving unit) 125 for advancing and retracting in the longitudinal direction of, and a the controller. Operation of Tensile processing unit 120 is controlled by the control unit.
[0078]
　Mounting closed-section portion holding member 121, the attachment member having a shape corresponding to the internal shape of the attachment closed cross-section portion 13W in the longitudinal direction of the torsion beam material W10 from the bottom of the recess 121U is formed closed cross-section portion holding member main body 121A When provided with a plurality of sets of clamping members 121B and the clamping member 121C which face each other, the.
[0079]
　Clamping member 121B, the drive unit such as an actuator be connected to the (not shown), which is retractable from the wall of the mounting closed-section portion holding member main body 121A inwardly.
[0080]
　Clamping member 121C is driven unit such as an actuator be connected to the (not shown), which is retractable from the convex portion of the attachment closed-section portion holding member main body 121A outward.
[0081]
　Clamping member 121B and the clamping member 121C is near mounting portion 14W of the attachment closed-section portion 13W of the torsion beam material W10, pinching and holding cooperate from the outside and inwardly.
[0082]
　A hydraulic cylinder (driving unit) 125, when receiving an instruction from the control unit, the mounting closed cross-section portion holding member 121, it is moved forward and backward in the longitudinal direction of the torsion beam material W10 along the arrow T120.
[0083]
　That is, by the control unit, pulling in the longitudinal direction in a state in which the pair of mounting closed-section portion holding member 121 is held respectively mounted closed-section portion 13W at the ends of the torsion beam material W10. In the present embodiment has a form to pull both ends of the torsion beam material W10, not limited to this embodiment, a pair of mounting closed-section portion holding member 121 is a mounting closed-section portion 13W at the ends of the torsion beam material W10, respectively after holding, fixing the position of one of the pair of attaching the closed-section portion holding member 121, by relatively separating the other to the one, forms applying tension to the torsion beam material W10 also be employed is there. This point, other embodiments are also the same.
[0084]
　Next, referring to FIG. 8 (A) ~ FIG 8 (E), an outline of a tensile treatment process using the torsion beam manufacturing apparatus 100. Figure 8 (A) ~ FIG 8 (E) are views for explaining along the flow of the respective pulling process FIG 8 (A) ~ FIG 8 (E) in the torsion beam manufacturing process, A of FIG. 7 it is a view corresponding to part. The tensile process below, by the control unit may be all carried out automatically.
[0085]
(1) First, as shown in FIG. 8 (A), and supported by placing the torsion beam material W10 on the torsion beam material supporting table 110, to advance the attached closed cross-section portion holding member 121 in the arrow T120F direction.
(2) Next, as shown in FIG. 8 (B), When mounting closed cross-section portion holding member 121 is positioned in the vicinity of the mounting portion 14W of the attachment closed-section portion 13W of the torsion beam material W10, mounting closed cross-section portion holding member 121 the stops.
　Then, the clamping member 121B and the clamping member 121C is protruded as shown by an arrow, to hold the mounting closed cross-section portion 13W.
(3) Next, as shown in FIG. 8 (C), After holding the mounting closed cross-section portion 13W by clamping members 121B and the clamping member 121C, a torsion beam material W10 by operating the hydraulic cylinder (not shown) in the longitudinal direction along pull the arrow T120P direction. This tension process, the torsion beam material W10, by giving the distortion of 1% or more in the axial direction, certainly, it is possible to release the residual stress in the front and back surfaces in the thickness direction.
(4) When the tension of the torsion beam material W10 is completed, it has finished the torsion beam 10. Thereafter, as shown in FIG. 8 (D), it is retracted to indicate clamping member 121B and the clamping member 121C to the arrow. Thereby, the holding of the attachment closed-section portion 13W according to attach the closed-section portion holding member 121 is released.
(5) When the clamping member 121B and the clamping member 121C is retracted to a predetermined position, as shown in FIG. 8 (E), with the mounting closed cross-section portion holding member 121 is retracted in the arrow T120R direction tensile process is completed.
[0086]
　Referring to FIG. 9 (A) ~ FIG 11 (B), illustrating the effect of the elongation process according to the first embodiment.
　Figure 9 (A) ~ FIG. 11 (B) is a diagram for explaining a tensile effect of treatment according to the first embodiment. FIGS. 9 (A) and 9 Fig 9 (B) indicates the stress distribution in the closed cross section at the same position as FIG. 5A, stress FIGS. 10 (A) and 10 (B) is in the closed section at the same position as FIG. 5B distribution indicates, FIGS. 11 (a) and 11 (B) shows the stress distribution in the closed cross section at the same position as Figure 5C. In FIG. 9 (A) ~ FIG 11 (B), the black portion indicates a higher tensile residual stress portion, shaded portion indicates the portion of the medium tensile residual stress, colorless portions tensile residual stress is almost no part the shows.
[0087]
　First, FIG. 9 (A), the referring to FIG. 9 (B), illustrating the effect of the tensile process in constant shape closed-section portion 11. Figure 9 (A) is tensile pretreatment stress distribution, FIG. 9 (B) shows the stress distribution after stretching treatment.
　Residual stress in a certain shape closed-section portion 11 is in the state at the time of molding the torsion beam material W10, as shown in cross section in FIG. 9 (A), the high tensile stress is the thickness direction over substantially the entire periphery of the contact portion S150A widely distributed.
　The tensile residual stress is almost nonexistent portion, the second wall portion S120A side forming the convex side outer surface, there from the outside in the thickness direction in the region of the tensile residual stress is approximately 1/3 inwardly are doing. On the other hand, the tensile residual stress in the first wall portion S110A side forming a concave side inner surface hardly exists.
　In contrast, after the elongation process, as shown in cross section in FIG. 9 (B), the high tensile residual stress, adhesion portion first wall portion S110A side of S150A, very both second wall portion S120A side distribution has been reduced, the tensile residual stress is no longer almost non-existent. Therefore, it is possible to improve the fatigue properties.
[0088]
　Next, FIG. 10 (A), the referring to FIG. 10 (B), illustrating the effect of the elongation process at the connecting portion 12A. Figure 10 (A) is tensile pretreatment stress distribution, FIG. 10 (B) shows the stress distribution after stretching treatment.
　Residual stress in the connecting portion 12A is in the state at the time of molding the torsion beam material W10, FIG. 10 as shown in cross-section S12B, from the folded wall portion S130B vicinity of closed cross section inwardly S150B in the width direction center side of the (A) high tensile residual stress to the middle position are distributed.
　Moreover, almost nonexistent portions, but are present outside in the width direction substantially central position of the second wall portion S120B side forming the convex side outer surface, the first wall portion S110B side forming a concave side inner surface of the tensile residual stress hardly exist in.
　In contrast, after the elongation process, as shown in the sectional S12B of FIG. 10 (B), over substantially the entire range, the tensile residual stress is no longer almost exist.
　For even cross section shown in FIG. 10 (A) and FIG. 10 (B), the above shown in FIG. 9 (A) and FIG. 9 (B) are shown it is possible to obtain the same effect as fatigue improvements in cross-section. That is, in this embodiment, by pulling the torsion beam material W10 in the longitudinal direction, as shown in FIG. 10 (B), it is possible to reduce the residual stress, thereby improving the fatigue characteristics.
[0089]
　Next, FIG. 11 (A), the with reference to FIG. 11 (B), illustrating the effect of the tensile process in shape changing portion 12. Figure 11 (A) shows the stress distribution before pulling process, FIG. 11 (B) shows the stress distribution after stretching treatment.
　Residual stress in the shape changing part 12 is in the state where the molded torsion beam material W10, as shown in cross section in FIG. 11 (A), the thickness in the second wall portion S120C side forming the convex side outer surface of the closed cross section inwardly S150C slightly distributed inward direction, the first wall portion S110C side forming a concave side inner surface, high tensile residual stresses from the vicinity folded wall portion S130C to the middle of the widthwise center side is distributed over the entire range of the plate thickness direction ing.
　The portion tensile residual stress hardly exist, first wall portion S110C side, both the second wall portion S120C side, very small.
　In contrast, after the elongation process, as the cross section shown in FIG. 11 (B), portions tensile residual stress is hardly present and greatly expanded, portions of the high tensile residual stress will not be present.
　For even cross-section shown in FIG. 11 (A) and FIG. 11 (B), above shown in FIG. 9 (A) and FIG. 9 (B) are shown it is possible to obtain the same effect as fatigue improvements in cross-section. That is, in this embodiment, by pulling the torsion beam material W10 in the longitudinal direction, as shown in FIG. 11 (B), it is possible to reduce the residual stress, thereby improving the fatigue characteristics.
[0090]
　Torsion beam manufacturing method according to the first embodiment, and according to the torsion beam manufacturing apparatus 100, it is possible to manufacture the torsion beam 10 that is fatigue characteristics excellent efficiently.
[0091]
　Further, torsion beam manufacturing method according to the first embodiment, and according to the torsion beam manufacturing apparatus 100, and holds the mounting closed-section portion 13W of the torsion beam material W10, since pulling the connecting portion 12A in the longitudinal direction, the entire length of the torsion beam material W10 over Hippareru. As a result, it is possible to remove a certain shape closed cross-section portion 11W, without leakage in the entire range of shape changing portion 12W tensile residual stress of the torsion beam material W10.
[0092]

　Next, with reference to FIGS. 12 and 13 (A) ~ FIG 13 (D), a description of a second embodiment of the present invention.
　Figure 12 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus according to a second embodiment of the present invention, FIG. 13 (A) ~ FIG 13 (D) is a process of manufacturing the torsion beam according to a second embodiment it is a diagram for explaining the outline. 12, reference numeral 100A denotes a torsion beam manufacturing apparatus.
　The second embodiment differs from the first embodiment, a method of holding the torsion beam material W10 when pulling handle torsion beam material W10 is different.
[0093]
　Referring to FIG 12, it will be described a schematic configuration of the torsion beam manufacturing apparatus 100A according to the second embodiment.
　The torsion beam manufacturing apparatus 100A, as shown in FIG. 12, the torsion beam material supporting table 110 for mounting the torsion beam material W10, a pair of tensile processing units 120A to pull the torsion beam material W10 in the longitudinal direction, a control unit (not shown) It is equipped with a.
[0094]
　Tensile processing unit 120A, as shown in FIG. 12, a change in shape outer side holding member 1210 that holds the shape changing portion 12W and attached closed-section portion 13W from outside, the shape changing portion 12W and mounting the closed-section portion 13W a shape changing portion supporting the punch (inner support member) 122 which supports from the inside, along a shape change portion supporting the punch 122 in the longitudinal direction of the torsion beam material W10 and a hydraulic cylinder 125 for advancing and retracting the arrow T120 direction.
[0095]
　Shape change outer side holding member 1210 includes an upper outer holder 1211 formed corresponding to the upper contour of the shape-changing portion 12W and attached closed-section portion 13W of the torsion beam material W10, shape changing portion 12W and mounting the closed-section portion a lower outer holding portion 1212 formed corresponding to the lower outer shape of 13W, to these upper outer holding portion 1211 and the lower outer holding portion 1212 arrow T121Y direction (tensile direction) and arrow T121Z (holding direction) driver such as actuators for advancing and retracting is provided with a (not shown) and.
[0096]
　The upper outer retaining portion 1211 includes an upper outer holding profile portion which is complementarily formed to the upper outline of the shape-changing portion 12W and attached closed cross-section portion 13W, are connected to a drive unit (not shown).
[0097]
　Lower outer holding portion 1212 has a lower outer holding shaped portion which is complementarily formed to the lower contour of the shape-changing portion 12W and attached closed cross-section portion 13W, are connected to a drive unit (not shown).
[0098]
　Shape changing portion supporting the punch 122, for example, be formed to correspond to the inner shape of the shape changing portion 12W and attached closed cross-section portion 13W, the shape changing portion with which is insertable into the inside of the shape-changing portion 12W 12W the support from the inside.
　Specifically, the shape changing portion supporting the punch 122 has an inner shape complementary-formed shape changing portion inner side holding the shape of the shape changing portion 12W.
[0099]
　Tensile processing unit 120A is controlled by a control unit (not shown).
　Specifically, the hydraulic cylinder 125 receives an instruction from the control unit, advancing and retracting the shape-changing portion supporting the punch 122 in the arrow T120 direction.
[0100]
　Referring to FIG. 13 (A) ~ FIG 13 (D), to describe an example of a schematic of a torsion beam manufacturing process by torsion beam manufacturing apparatus 100A. Figure 13 (A) ~ FIG 13 (D) are diagrams for explaining the outline of manufacturing steps of the torsion beam according to a second embodiment.
[0101]
(1) First, as shown in FIG. 12 and FIG. 13 (A), the support by placing the torsion beam material W10 on torsion beam material supporting table 110, to arrange the shape change outer side holding member 1210 in position.
(2) Next, as shown in FIG. 13 (B), the shape changing portion supporting the punch 122 is advanced in the arrow T120F direction inserted to the inside of the shape-changing portion 12W, the shape changing portion supporting the punch 122 shape change When you support the part 12W from the inside to stop.
(3) Next, as shown in FIG. 13 (C), by a drive unit (not shown), the upper outer holding portion 1211 and the lower outer holding portion 1212 is advanced in the arrow T121Z direction, these upper outer holding portion 1211 and retaining the shape changing portion 12W and attached closed-section portion 13W from above and below by the lower outer holding portion 1212.
(4) Then, as shown in FIG. 13 (D), as well as supported by the shape changing portion supporting the punch 122 and the shape changing portion 12W and attached closed-section portion 13W from the inside, upper outer holding portion 1211 and the lower outer holding pulling the arrow T121P direction while holding the shape changing portion 12W and attached closed-section portion 13W by part 1212, to form the torsion beam 10. At this time, the shape changing portion supporting the punch 122 includes an upper outer holding portion 1211 and the lower outer holding portion 1212 synchronous or follow to move in the arrow T120R direction. This tension process, the torsion beam material W10, by giving the distortion of 1% or more in the axial direction, certainly, it is possible to release the tensile residual stress in the front and back surfaces in the thickness direction.
[0102]
　Torsion beam manufacturing method according to the second embodiment, according to the torsion beam manufacturing devices 100A, it is possible to reduce the residual stress of the connection part 12A, to produce a torsion beam 10 that is fatigue characteristics excellent efficiently.
[0103]
　Further, according to the torsion beam manufacturing devices 100A, by inserting a shape-changing portion supporting the punch 122 to the inside of the shape changing portion 12W and attached closed cross-section portion 13W, the shape changing portion 12W and attachment closed by the shape changing portion supporting the punch 122 supporting the cross section 13W from the inside. Then, the upper outer holding portion 1211 and the lower outer holding portion 1212 while holding the shape changing portion 12W and attached closed cross-section portion 13W, so pulling the torsion beam material W10 in its longitudinal direction, so that the shape changing part 12W is crushed suppressing the deformation enables stable pulling process.
[0104]

　Next, with reference to FIGS. 14 to 16 (E), a description of a third embodiment of the present invention.
　Figure 14 is a flowchart illustrating a torsion beam of the manufacturing process according to a third embodiment of the present invention. Further, FIG. 15 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus according to this embodiment, FIG. 16 (A) ~ FIG 16 (E) is an outline of the process of manufacturing the torsion beam according to this embodiment it is a diagram. 15, reference numeral 100B indicates a torsion beam manufacturing apparatus.
[0105]
　In the first embodiment, in advance by molding a torsion beam material W10 performed beforehand stamping, then, it was prepared the torsion beam 10 and torsion beam material W10 tensile processed to a torsion beam manufacturing apparatus 100. In contrast, in the present embodiment, it is implementing both the pressing and tensile processed by torsion beam manufacturing apparatus 100A. Incidentally, the other points of this embodiment are similar to those of the aforementioned first embodiment.
[0106]
　Referring to FIG. 14, described torsion beam manufacturing process according to the present embodiment.
(1) preparing a metal material tube (step S201).
　The metal material pipe to be prepared, for example, it is possible to wall thickness used uniform Tubular.
(2) Next, in the pressing Tensile process, the pressing and tensile treating a metal material tube (step S202).
　In the press working Tensile process, a metallic material tube by forming a torsion beam material W10 by pressing, then, it remains in its installed state, continuing the pulling process torsion beam material W10. This tension process, the torsion beam material W10, by giving the distortion of 1% or more in the axial direction, certainly, it is possible to release the tensile residual stress in the front and back surfaces in the thickness direction.
(3) by pressing Tensile processing in step S202, the torsion beam 10 is formed (step S203).
[0107]
　Next, referring to FIG. 15, will be described a schematic configuration of the torsion beam manufacturing apparatus 100B according to the present embodiment.
　The torsion beam manufacturing apparatus 100B includes, as shown in FIG. 15, a press-forming the fixed mold 110A, a pair of tensile processing unit 120, and the press molding movable die drive unit 130A, the control unit (not shown).
　In the torsion beam manufacturing apparatus 100B, a press molding fixed 110A and the press molding movable die drive unit 130A constitute a press machine, a pair of tensile processing unit 120 constitutes a tensile processing machine.
　Since the configuration and operation of the tension processing unit 120 is the same as the first embodiment, a repeated explanation thereof are denoted by the same reference numerals.
[0108]
　Press forming fixed (mold) 110A, the recess is used to obtain the torsion beam material W10 metallic material tube pressing to 110AU is formed. That is, the press-molding fixed 110A, recesses 110AU having a shape corresponding to the lower surface of the torsion beam material W10 is formed faces upward.
　Further, press forming fixed 110A, at the time of pulling handle torsion beam material W10 by a pair of tension processing unit 120 is also a torsion beam material support base for supporting the torsion beam material W10.
[0109]
　Press molding movable die drive unit 130A includes press-forming the movable mold with (mold) 131, and a hydraulic cylinder (driving unit) 135 for advancing and retracting the press molding movable die 131 in the arrow T130 direction (elevation).
　Press molding the movable mold 131 is formed shaped portion for forming a torsion beam material W10, forming a torsion beam material W10 in cooperation with the press molding fixed 110A. The lower surface of the press-molding movable die 131, the shape corresponding to the upper surface of the torsion beam material W10, are formed faces downward.
[0110]
　Wherein the control unit (not shown), each pulling a processing unit 120 and the press molding movable die drive unit 130A, and instructs the operation regarding pressing and tensile processing.
[0111]
　Referring to FIG. 16 (A) ~ FIG 16 (E), will be outlined in the torsion beam manufacturing process by torsion beam manufacturing apparatus 100B. Figure 16 (A) ~ FIG 16 (E) is a diagram illustrating a process of producing the torsion beam according to the present embodiment along the flow of FIG. 16 (A) ~ FIG 16 (E), C in FIG. 15 it is a view corresponding to part.
[0112]
(1) First, as shown in FIG. 16 (A), placing a metal material tube W0 onto the press molding fixed 110A, moves the press-molding movable die 131 in the arrow T130F direction (downward).
(2) Next, as shown in FIG. 16 (B), When torsion beam material W10 is molded to move the press-molding movable die 131 in the arrow T130R direction (upward). Then, to advance the attached closed cross-section portion holding member 121 in the arrow T120F direction.
(3) Next, as shown in FIG. 16 (C), When mounting closed cross-section portion holding member 121 is positioned in the vicinity of the mounting portion 14W of the attachment closed-section portion 13W of the torsion beam material W10, forward mounting closed-section portion holding member 121 the stops.
　Then, the clamping member 121B and the clamping member 121C, to protrude in the direction of the arrow so as to approach each other.
(4) Then, as shown in FIG. 16 (D), by sandwiching the attachment closed cross-section portion 13W by clamping members 121B and the clamping member 121C, to retain the vicinity of the mounting portion 14W of the torsion beam material W10.
(5) Then, as shown in FIG. 16 (E), the left while holding the mounting closed cross-section portion 13W by clamping members 121B and the clamping member 121C, by operating the hydraulic cylinder (hydraulic cylinder 125 shown in FIG. 15) the torsion beam material W10 along its longitudinal direction to form the torsion beam 10 by pulling process the arrow T120P direction. This tension process, the torsion beam material W10, by giving the distortion of 1% or more in the axial direction, certainly, it is possible to release the tensile residual stress in the front and back surfaces in the thickness direction.
　After the formation of the torsion beam 10, FIG. 8 in the first embodiment (D), is the same as the operation described with reference to FIG. 8 (E), the duplicated description thereof is omitted here.
[0113]
　Torsion beam manufacturing method according to the present embodiment, according to the torsion beam manufacturing apparatus 100B, it is possible to manufacture the torsion beam 10 that is fatigue characteristics excellent efficiently.
[0114]
　Further, according to the torsion beam manufacturing apparatus 100B according to the present embodiment, after forming the torsion beam material W10 metallic material tube W0 is pressed without transferring the torsion beam material W10 to other devices, continue to torsion beam material W10 since the production of the torsion beam 10 by pulling, it is possible to improve the productivity.
[0115]

　Next, with reference to FIGS. 17 to 18 (E), a description of a fourth embodiment of the present invention.
　Figure 17 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus 100C according to this embodiment. Figure 18 (A) ~ FIG 18 (E) are diagrams for explaining the outline of the torsion beam manufacturing process according to the present embodiment along the flow of FIG. 18 (A) ~ FIG 18 (E), 17 it is a view corresponding to the D portion.
[0116]
　Referring to FIG 17, it will be described a schematic configuration of the torsion beam manufacturing apparatus 100C according to this embodiment.
　The torsion beam manufacturing apparatus 100C includes a press forming fixed (mold) 110B, a pair of tensile processing unit 120B, and the press molding movable die drive unit 130B, the control unit (not shown).
　In the torsion beam manufacturing apparatus 100C, a press molding fixed 110B and the press molding movable die drive unit 130B constitute a press machine, a pair of tensile processing unit 120B constitutes a tensile processing machine.
[0117]
　Press forming fixed (mold) 110B, the recess is used to obtain the torsion beam material W10 metallic material tube W0 pressing to 110BU is formed. That is, the press-molding fixed 110B, recess 110BU having a shape corresponding to the lower surface of the torsion beam material W10 is formed faces upward.
　Further, press forming fixed 110B, when pulling handle torsion beam material W10 by a pair of tension processing unit 120B, is also a torsion beam material support base for supporting the torsion beam material W10.
[0118]
　Press molding fixed 110B is constant shape closed cross-section portion and the first support portion 111B having a shape corresponding to 11W, the shape changing portion 12W and attached closed-section portion 13W second pair having a corresponding shape to the torsion beam material W10 includes a support portion 112B, is disposed in the first supporting portion 111B, and a first actuator (shape change absorbing means) such as a hydraulic cylinder for advancing and retracting the second supporting portion 112B in the arrow T112 direction with respect to the support portion 111B 113B ing. The actuator 113B is provided one for each of the second supporting portion 112B.
[0119]
　Press molding movable die drive unit 130B includes press-forming the movable mold with (mold) 132, and a hydraulic cylinder (driving unit) 135 for advancing and retracting the press molding movable die 132 in the arrow T130 direction (elevation).
　The lower surface of the press-molding movable die 132, be formed shape corresponding to the upper shape of the torsion beam material W10, obtain torsion beam material W10 metallic material tube W0 pressing to cooperate with a press molding fixed 110B .
[0120]
　Each tensile processing unit 120B, respectively, as shown in FIG. 17, the shape-changing portion supporting the punch (inner support member) 122, a shape change portion supporting the punch 122 in the arrow T120 direction along the longitudinal direction of the torsion beam material W10 and a hydraulic cylinder 125 for advancing and retracting.
[0121]
　Each shape-changing portion supporting the punch 122, respectively, have been formed in a shape corresponding to the internal shape of the shape changing portion 12W and attached closed cross-section portion 13W, it is inserted into the inside of the shape-changing portion 12W shape changing portion 12W supported from the inside.
　Specifically, the shape-changing portion supporting the punch 122 is provided with an internal shape of the shape changing portion 12W complementarily formed shape changing portion inner side holding-shaped portion, respectively.
[0122]
　Each hydraulic cylinder 125, respectively, by instruction from the control unit (not shown), advancing and retracting the shape-changing portion supporting the punch 122 in the arrow T120 direction.
[0123]
　Press molding movable die drive unit 130B includes press-forming the movable mold with (mold) 132, and a hydraulic cylinder (driving unit) 135 for advancing and retracting the press molding movable die 132 in the arrow T130 direction (elevation).
[0124]
　Press molding the movable mold 132, as shown in FIG. 17, a first molding part 132A, the longitudinal direction respectively on both sides arranged two second mold (shape-changing portion support member) of the first mold portion 132A 132B and , and a pair of hydraulic cylinders the second molding portion 132B is moved in the arrow T132 direction (shape-changing portion supporting member driving unit) 132C.
　The lower surface of the press-molding movable die 132, be formed shape corresponding to the upper shape of the torsion beam material W10, press molding the torsion beam material W10 in cooperation with the press molding fixed 110B.
[0125]
　Wherein the control unit (not shown), each actuator 113B of the press molding fixed 110B, the puller processing unit 120B, and to the press molding movable die drive unit 130B, direct the operation regarding pressing and tensile processing.
[0126]
　Each actuator 113B is displaced in response to longitudinal shape change due to the molding process of the torsion beam material W10 (elongation). Specifically, operating the hydraulic cylinders (shape-changing portion supporting member driving unit) movement of 132C and synchronization or tracking to.
[0127]
　Wherein the control unit includes a respective actuator 113B of the press molding fixed 110B, the hydraulic cylinders (shape-changing portion supporting member driving unit) which is arranged in the press molding movable die 132 and synchronously advancing and retreating 132C.
　Each hydraulic cylinder 125 is operated actuators 113B and the hydraulic cylinders 132C and synchronization or tracking to.
[0128]
　Referring to FIG. 18 (A) ~ FIG 18 (E), will be outlined in the torsion beam manufacturing process by torsion beam manufacturing apparatus 100C. Figure 18 (A) ~ FIG 18 (E) are views for explaining along the flow of the manufacturing steps of the torsion beam according to the present embodiment FIG. 18 (A) ~ FIG 18 (E), in Fig. 17 it is a view corresponding to D unit.
[0129]
(1) First, as shown in FIG. 18 (A), placing a metal material tube W0 for press molding fixed 110B on, moving the press forming movable mold 132 in the arrow T130F direction.
　At this time, the first support portion 111B and the second supporting portion 112B come together, so as to form a recess 110BU a shape corresponding to the lower shape of the torsion beam material W10, each actuator 113B is retracted.
(2) Then, as shown in FIG. 18 (B), the torsion beam material W10 is press-formed by sandwiching a metal material tube W0 between the press molding fixed 110B and the press molding movable die 132.
(3) Next, as shown in FIG. 18 (C), the shape changing portion supporting the punch 122 is advanced in the arrow T120F direction inserted up to the inside of the shape-changing portion 12W. As a result, the shape changing portion supporting the punch 122 comes into contact with the shape-changing portion 12W of the torsion beam material W10, it supports the shape changing portion 12W and attached closed-section portion 13W from the inside thereof.
(4) Then, as shown in FIG. 18 (D), by cooperation of the cylinder 132C and the actuator 113B, the second molding portion 132B is moved forward in the arrow T132P direction, a shape change portion supporting the punch 122 second forming pulling the torsion beam material W10 in the longitudinal direction in a state where the section 132B supporting the shape changing portion 12W. Further, the second support portion 112B to form a torsion beam 10 advances in the arrow T112P direction in synchronization with the second molding portion 132B. At this time, the shape changing portion supporting the punch 122 is retracted in the arrow T120R direction in synchronization with the second molding portion 132B and the second supporting portion 112B.
　This tension process, the torsion beam material W10, by giving the distortion of 1% or more in the axial direction, certainly, it is possible to release the tensile residual stress in the front and back surfaces in the thickness direction.
(5) After forming the torsion beam 10, as shown in FIG. 18 (E), retracting the second supporting portion 112B by the actuator 113B with retracting the second molding portion 132B in the arrow T132R direction by the cylinder 132C the arrow T112R direction . The shape changing portion supporting the punch 122 is retracted in the arrow T120R direction. Further, press forming the movable mold 132 is moved (raised) by the arrow T130R direction.
[0130]
　Torsion beam manufacturing method according to the present embodiment, according to the torsion beam manufacturing apparatus 100C, it is possible to manufacture the torsion beam 10 that is fatigue characteristics excellent efficiently.
[0131]
　Further, according to the torsion beam manufacturing apparatus 100C, the shape changing portion supporting the punch 122 because the second molding portion 132B pulls the torsion beam material W10 in the longitudinal direction while holding the shape changing portion 12W cooperate connecting portion 12A tensile residual stress can be reduced or removed the.
[0132]
　Further, according to the torsion beam manufacturing apparatus 100C, when pulling the torsion beam material W10 longitudinally is provided with the actuator 113B displaced with the shape change in the longitudinal direction due to a tensile processing of the torsion beam material W10, elongated torsion beam W10 even when the outer shape of the direction center side both adjacent larger, it is possible to easily pull process.
[0133]
　Further, according to the torsion beam manufacturing apparatus 100C, is provided with the actuator 113B, to suppress the torsion beam material W10 is being damaged during the elongation process, efficiently residual stress can be reduced.
[0134]
　Further, according to the torsion beam manufacturing apparatus 100C, after forming the torsion beam material W10 metallic material tube W0 pressing to, it can be manufactured with torsion beam 10 continues pulling the torsion beam material W10 without transferring to another device, production it is possible to improve the sex.
[0135]
　Further, according to the torsion beam manufacturing apparatus 100C, since the second molding part 132B is moved in the arrow T132 direction by a hydraulic cylinder (shape-changing portion supporting member driving unit) 132C, the moving speed and the moving timing of the second molding portion 132B easy and it can be efficiently controlled.
[0136]

　Next, with reference to FIGS. 19 to 20 (E), a description of a fifth embodiment of the present invention.
　Figure 19 is a front view illustrating a schematic configuration of a torsion beam manufacturing apparatus 100D according to the present embodiment. Figure 20 (A) ~ FIG 20 (E) is a diagram illustrating a process of producing the torsion beam according to the present embodiment along the flow of FIG. 20 (A) ~ FIG 20 (E), E of FIG. 19 it is a view corresponding to part.
[0137]
　Referring to FIG 19, it will be described a schematic configuration of the torsion beam manufacturing apparatus 100D according to the present embodiment.
　The torsion beam manufacturing apparatus 100D includes a press forming fixed (mold) 110A, a pair of tensile processing unit 120B, and the press molding movable die drive unit 130C, the control unit (not shown).
　In the torsion beam manufacturing apparatus 100D, a press molding fixed 110A and the press molding movable die drive unit 130C constitutes a press machine, a pair of tensile processing unit 120B constitutes a tensile processing machine.
　The configuration and operation of press-forming the fixed mold 110A is the same as the third embodiment, also, since the configuration and operation of the tension processing unit 120B is the same as in the fourth embodiment are denoted by the same reference numerals the duplicated description thereof is omitted.
[0138]
　Press molding movable die drive unit 130C includes press-forming the movable mold with (mold) 133, and a hydraulic cylinder (driving unit) 135 for advancing and retracting the press molding movable die 133 in the arrow T130 direction (elevation).
[0139]
　Press molding the movable mold 133, as shown in FIG. 19, a first molding part 133A, both longitudinal sides respectively arranged two second mold (shape-changing portion support member) of the first mold portion 133A 133B and a cam surface (cam mechanism) 133C, and a guide member 133D of the second molding portion 133B is guided to move in the horizontal direction with respect to the first mold portion 133A, a press molding movable type base member 134, the cam follower support member and 133E, and it includes a cam follower (cam mechanism) 133F, a spring 133S, and restoring means for moving the second molding portion 133B to the first mold portion 133A side (not shown), a.
　Further, on the lower surface of the press-molding movable die 133, it is formed shape corresponding to the upper shape of the torsion beam material W10, press molding the torsion beam material W10 in cooperation with the press molding fixed 110A.
[0140]
　Cam surfaces 133C are formed on the inner surface of the second molding portion 133B, side away with the cam follower 133F is an inclined surface which is inclined closer towards the first molding part 133A. The gap formed between the cam follower 133F and the opposing surface, which is tapered toward the pressing direction of the press-molding movable die 133.
　The cam follower support member 133E is formed so as to extend toward the cam surface 133C side of the lower surface of the press-molding movable die base member 134.
　Cam follower 133F is composed of, for example, a roller, is rotatably provided on the distal end side of the cam follower support member 133E.
　Cam surfaces 133C and the cam follower 133F constitute a cam mechanism that moves the second mold portion 133B in the longitudinal direction of the torsion beam material W10.
[0141]
　Spring 133S is provided several between the guide member 133D and the press molding movable die base member 134. After torsion beam material W10 was formed by first forming portion 133A and the second mold part 133B, that is further lower the press molding movable die base member 134, between the press-molding movable die base member 134 and the guide member 133D distance is changed, it is possible to displace the position of the cam follower 133F relative to the cam surface 133C.
[0142]
　Controller (not shown), the tensile processing unit 120B and the press molding movable die drive unit 130C, directs the operation regarding pressing and tensile processing.
[0143]
　Referring to FIG. 20 (A) ~ FIG 20 (E), will be outlined in the torsion beam manufacturing process by torsion beam manufacturing apparatus 100D. Figure 20 (A) ~ FIG 20 (E) are views for explaining along the flow of the manufacturing steps of the torsion beam according to the fifth embodiment FIG. 20 (A) ~ FIG 20 (E), 19 it is a view corresponding to the E portion.
[0144]
(1) First, as shown in FIG. 20 (A), a metal material tube W0 placed on the press molding fixed 110A, moves the press-molding movable die 133 in the arrow T130F direction.
(2) As shown in FIG. 20 (B), by press molding using a press molding fixed 110A and a press molding movable die 133, torsion beam material W10 is molded.
(3) Next, as shown in FIG. 20 (C), to advance the shape-changing portion supporting the punch 122 in the arrow T120F direction.
(4) Then, as shown in FIG. 20 (D), the shape changing portion supporting the punch 122 Once in contact with the inside of the shape changing portion 12W of the torsion beam material W10, further arrow T133F direction press molding movable die base member 134 It is lowered.
　Is lowered further arrow T133F direction press molding movable die base member 134, the cam follower 133F contacts the cam surface 133C, the second mold portion 133B in the arrow T132F direction by the cam follower 133F is moved along the cam surface 133C to advance. As a result, the shape changing portion supporting the punch 122 and the torsion beam material W10 shape changing portion 12W in the supporting state by the second molding portion 133B by pulling in the longitudinal direction thereof to form a torsion beam 10. This tension process, the torsion beam material W10, by giving the distortion of 1% or more in the axial direction, certainly, it is possible to release the tensile residual stress in the front and back surfaces in the thickness direction.
(5) After forming the torsion beam 10, as shown in FIG. 20 (E), by increasing the press-molding movable die base member 134 in the arrow T130R direction, a press-molding movable die base member 134 first molded portion 133A, the second It is separated from the second forming unit 133B. Thus, the second mold restoring means by the cam follower 133F is moved on the upper side of the cam surface 133C (not shown) by the second mold is retracted in the arrow T132R direction.
　Also, retracting the shape-changing portion supporting the punch 122 in the arrow T120R direction.
[0145]
　Torsion beam manufacturing method according to the fifth embodiment, according to the torsion beam manufacturing apparatus 100D, it is possible to manufacture the torsion beam 10 that is fatigue characteristics excellent efficiently.
[0146]
　Further, according to the torsion beam manufacturing apparatus 100D, the cam mechanism is operated by a stroke for moving the press-molding movable die 133 in the arrow T130F direction. Since pulling the shape changing portion supporting the punch 122 and the torsion beam material W10 while holding the shape changing portion 12W by the second molding portion 133B in the longitudinal direction outward, reduce or effectively remove residual stresses from the connection portion 12A be able to.
[0147]
　Further, according to the torsion beam manufacturing apparatus 100D, after forming the torsion beam material W10 metallic material tube W0 is pressed, since Hippareru continue torsion beam material W10 without transferring to another device, the production in the manufacture of the torsion beam 10 it is possible to improve the sex.
[0148]
　Further, according to the torsion beam manufacturing apparatus 100D, since advancing a second forming unit 133B in the arrow T133 direction by the cam mechanism, it is possible to operate the second molding portion 133B by a simple structure.
[0149]
　The present invention is not limited only to the embodiments described above without departing from the scope and spirit of the present invention, it is possible to make various changes.
[0150]
　For example, in the first embodiment, it has been described a case where the torsion beam manufacturing apparatus 100 pulls the torsion beam material W10 holds the mounting portion 14 near the attachment closed-section portion 13W by mounting closed-section portion holding member 121 in the longitudinal direction. However, not limited only to this embodiment, the structure of mounting the closed-section portion holding member 121, the position for holding the torsion beam material W10 can be arbitrarily set as far as possible to pull the connection portion 12A.
[0151]
　In the embodiments described above, the press molding movable die (mold) 131, 132 and 133 has been described for the case of forward and backward by a hydraulic cylinder 135, for example, forward and backward by an actuator other than the crank mechanism or a hydraulic cylinder arrangement ( may be adopted not shown).
[0152]
　Further, the first, in the third embodiment, the longitudinal torsion beam material W10 by the hydraulic cylinder (driving unit) 125 holds the mounting closed cross-section portion 13W torsion beam manufacturing apparatus 100,100B is by attaching the closed-section portion holding member 121 has been described a case where pulling direction. However, not limited to this embodiment, the structure of mounting the closed-section portion holding member 121, the position for holding the mounting closed-section portion holding member 121, the configuration of the drive unit, set if any pulling the connection portion 12A it can.
[0153]
　Further, the second, in the fourth embodiment, the torsion beam manufacturing apparatus 100A, 100C is to retain the shape changing portion 12W by the second molding portion 132B, 133B and shape changing portion supporting the punch (inner support member) 122, has been described a case where pulling the torsion beam material W10 longitudinally. Further, the torsion beam manufacturing apparatus 100B is, by the shape change outer side holding member 1210 and the shape-changing portion supporting the punch (inner support member) 122 to retain the shape changing portion 12W, the case of pulling the torsion beam material W10 longitudinally explained. However, not limited only to these embodiments settings, configuration of holding members for holding the shape changing portion 12W, the position for holding the torsion beam material W10, the configuration of the drive unit, if possible optionally pulling the connection portion 12A it can.
[0154]
　Further, in the second embodiment, the shape change outer side holding member 1210 has been described the case that includes an upper outer holding portion 1211 and the lower outer holding portion 1212, for example, elongated torsion beam material W10 it may be divided into three or more when viewed along the direction.
　Further, in the second embodiment, the case has been described where the shape change outer side holding member 1210 holds the shape changing portion 12W and attached closed cross-section portion 13W, if the shape changing portion pulls the connection portion 12A 12W only may be held.
[0155]
　Further, in the second embodiment, the upper outer holding portion 1211, a lower outer holding portion 1212, the case of providing each and both of the shape changing portion 12W and attached closed-section portion 13W complementarily formed outer retention feature It was described. However, not limited to this embodiment, to the extent possible to pull the connection portion 12A, a part of the outer shape of the shape changing portion 12W and attached closed-section portion 13W only may be complementarily formed, outer holding profile portion It can be arbitrarily set for.
[0156]
　Further, in the above-described fourth embodiment, the case has been described where the torsion beam manufacturing apparatus 100C has an actuator (shape change absorbing means) 113B, whether provided with the actuator 113B can be arbitrarily set. Further, the torsion beam manufacturing apparatus of another embodiment may comprise an actuator 113B.
[0157]
　The shape changing portion supporting the punch (inner support member) 122, the actuator 113B, is either to follow or to synchronize the mutual operation of the hydraulic cylinder (shape-changing portion supporting member driving unit) 132C, it can be arbitrarily set.
[0158]
　In the above embodiments, the description has been given of the case where the inner side of closed cross section of the first wall portion S110A and the second wall portion S120 constituting a constant shape closed-section portion 11 is formed in close contact , whether to close contact with the first wall portion S110A and inner side of the second wall portion S120 can be set arbitrarily.
[0159]
　In the embodiments described above, the torsion beam 10, the description has been given of the case is substantially V-shape is convex to the lower side when mounted on the vehicle body is applied to a torsion beam which is formed into a substantially U-shaped may be, it may be configured to protrude upward relative to the vehicle body.
[0160]
　In the embodiments described above, a metal material tube W0 used for forming the torsion beam material W10 was described for the case where a uniform round steel pipe wall thickness. As the metal material tube W0, for example, or a metal tube formed by a welded tube formed by fatigue relieving thick shape corresponding portion is formed steel plate (metal material plate) by press molding or roll forming and plastic working, extrusion, it may be a metal tube formed by a pultrusion.
[0161]
　In the above embodiments, the metal material pipes used in the production of the torsion beam 10 has been described is a steel pipe may be a metal tube other than steel.
[0162]
　In the embodiments described above, as shown in FIG. 4, the shape of the attachment closed-section portion 13 has been described for the case where a straight longitudinally may be stepped shape. That is, for mounting closed cross-section portion 13, first forming a step, followed by modification to apply a tensile force in a state in which is engaged a shape change outer side holding member 1210 in the step may be employed.
[0163]
　Referring to the case of applying this modification with respect to the second embodiment, first, as shown in FIG. 21 (A), pushed shape changing unit support punch 122A (the inner support member) into the end of the torsion beam material W10 go in. Shape changing portion supporting the punch 122A has a relatively outer diameter dimension is smaller tip 122a1, relatively outer diameter dimension is large proximal portion 122a2, formed between these front end portion 122a1 and a proximal end 122a2 step and a part 122A3. Outer diameter of the tip 122A1 is one is insertable dimensions the mounting closed cross-section portion 13, the outer diameter of the base end portion 122A2 is made slightly larger than the inner diameter of the attachment closed-section portion 13.
[0164]
　For shape-changing portion supporting the punch 122A has such a stepped shape, when pushed against the mounting closed-section portion 13, as described above, the mounting portion 14 is a tube end of the attachment closed-section portion 13, the stepped portion It is expanded by 122A3 and a proximal end 122a2. As a result, as shown in FIG. 21 (A), the outer diameter of the portion of the mounting portion 14 of the attachment closed-section portion 13 is larger than the other portion, the engaging portion st is formed.
　Subsequently, to sandwich the mounting closed-section portion 13 from above and below by the upper outer holding portion 1211 and the lower outer holding portion 1212. At that time, the upper outer holding portion 1211 and the lower outer holding portion 1212 is positioned in advance so as not to crush locking portion st.
[0165]
　Subsequently, as shown in FIG. 21 (B), an upper outer holding portion 1211 and the lower outer holding portion 1212 and the shape changing portion supporting the punch 122A, is moved in synchronism in a direction away from the fixed shape closed-section portion 11 . Then, the upper outer holding portion 1211 and the lower outer holding portions 1212 each of the side end face 1211a, because 1212a is engaged with the engagement portion st, the tensile force of these upper outer holding portion 1211 and the lower outer holding portion 1212 ensures it is possible to impart to at least the connection portion 12A of the torsion beam material W10 to.
[0166]
　More say, in the second embodiment, when pulling the torsion beam material W10, so that not slip relative to the upper outer holding portion 1211 and the lower outer holding portion 1212, has been set to strengthen the grip. Then, so as not to excessively deform even under the gripping force, the shape change portion supporting the punch 122 has been used in combination as a core. In contrast, in this modification, to pull the attachment closed-section portion 13 primarily by engagement rather than friction, the gripping force by the upper outer holding portion 1211 and the lower outer holding portion 1212 relatively weakened also reliably be It applied a tensile force. Therefore, it is not necessary to use a shape-changing portion supporting the punch 122 as core, it is possible to omit the use of the shape-changing portion supporting the punch 122 in adding the tensile force as in FIG. 21 (B). The formation of the locking portion st may be carried out on the torsion beam manufacturing apparatus, or may be previously performed before placing the torsion beam manufacturing apparatus.
　In the above description, although the present modification has been described as applied to the second embodiment, it may also be applied to other embodiments as a matter of course.
[0167]
　The gist of the present invention based on the embodiments described above are summarized below.
(1) torsion beam manufacturing method according to an embodiment of the present invention, a constant shape closed-section portion 11 cross-section is a closed section of the substantially V-shaped or substantially U-shaped at any position in the longitudinal direction orthogonal to the longitudinal direction is a method of manufacturing a torsion beam 10 having a shape changing portion 12 having a connection portion 12A (connection region) having a closed cross section of constant shape closed cross-section portion 11 in continuous with and said closed section are different shapes. For example, as shown in FIG. 8 (A) ~ FIG 8 (E), for at least the connection portion 12A of constant shape closed-section portion 11 and the torsion beam material W10 shape changing portion 12 is formed, the longitudinal the tensile force along the added has a tensile obtaining a torsion beam 10.
　According to the torsion beam manufacturing method according to this aspect, tensile for applying a tensile force to at least the connecting portion 12A in the process, it is possible to reduce or eliminate the residual stress remaining.
　As a result, it is possible to produce an excellent torsion beam 10 on fatigue properties. Moreover, since it does not require post-heat treatment, it is possible to efficiently manufacture.
[0168]
(2) For example, as shown in FIG. 13 (A) ~ FIG 13 (D), the tension in the process, the inner shape changing portion supporting the outer portion along the longitudinal direction than the connecting portion 12A punch 122 ( is supported by the inner support member) and, in a state in which outside was engaging the upper outer holding portion 1211 (the outer locking member) of the outer portion, the shape changing portion supporting the punch 122 and the upper outer holding portion 1211 fixed by moving away from the shape closed cross-section portion 11, it may be added to the tension force.
　In this case, the tension step, in terms of supporting the inside of the outer portions of the torsion beam material W10 in shape changing portion supporting the punch 122, adding a tensile force to the upper outer holding portion 1211 to engage with the outside of the outer part since, it is possible to provide an easy to tensile force while suppressing the deformation of Dosotokata portion.
[0169]
(3) For example, as shown in FIG. 13 (A) ~ FIG 13 (D), in the tension step, support the outer of the connecting portion 12A at the lower outer holding portion 1212 (the outer support member), the shape changing portion the movement in the same direction of the support punch 122 and the upper outer holding portion 1211 and in synchronism, may be moved lower outer holding portion 1212.
　In this case, the lower outer holding portion 1212 to move in synchronism with the movement of the shape changing portion supporting the punch 122 and the upper outer holding unit 1211, it does not inhibit the extension of the torsion beam material W10 associated with tension. Therefore, since the tensile force can be applied to ensure the torsion beam material W10, it can be reduced or removed reliably residual stress.
[0170]
(4) For example, as shown in FIG. 8 (A) ~ FIG 8 (E), in the tension step, by relatively spaced along the across of the torsion beam material W10 in the longitudinal direction, the pulling force it may be added over the entire length of said torsion beam material W10.
　In this case, for pulling the torsion beam material W10 longitudinally outward over its entire length, the residual stress without leakage can be reduced or removed.
[0171]
(5) As mentioned in the above embodiments, in the tension step, may be imparted to the strain of 1% or more in the longitudinal direction relative to at least the connecting portion 12A of the torsion beam material W10.
　In this case, it is possible to impart sufficient tensile strength to cause eliminate or reduce residual stresses in the torsion beam material W10.
[0172]
As shown in (6) for example, FIG. 16 (A) ~ FIG 16 (C), prior to the pulling step includes a pressing step of obtaining a torsion beam material W10 metallic material tube W0 (the mother tube) by pressing it may be.
　In this case, at the time after the pressing step, there remains a residual stress torsion beam material W10, it can be followed by pulling process, to remove it.
[0173]
(7) As shown in FIG. 15 for example, the torsion beam manufacturing apparatus 100B according to one embodiment of the present invention, the closing of substantially V-shaped or substantially U-shaped cross section perpendicular to the longitudinal direction at any position in the longitudinal direction constant shape closed-section portion 11 is a cross-sectional, with a shape changing portion 12 having a connecting portion 12A having a closed cross section of constant shape closed cross-section portion 11 in continuous with and the closed section shape different (connection area) is an apparatus for manufacturing the torsion beam 10. Then, certain of the shapes closed-section portion 11 and the torsion beam material W10 shape changing portion 12 is formed, the portion in the longitudinal connecting portions 12A (connection region) when viewed along the other hand of the side of the torsion beam material W10 When connecting portion a pair of tensile processing unit for holding the part on the other side than the 12A 120 (holding mechanism) and; hydraulic cylinder 125 for relatively spaced between respective extension processing unit 120 (first driving mechanism) When; comprises.
　According to the torsion beam manufacturing apparatus 100B according to this embodiment, the pair of pulling the processing unit 120 and the hydraulic cylinder 125, by adding a longitudinal tensile force at least to the connection section 12A (connection region) of the torsion beam material W10 , it is possible to reduce or eliminate the residual stress remaining in the torsion beam material W10.
　As a result, it is possible to produce an excellent torsion beam 10 on fatigue properties. Moreover, since it does not require post-heat treatment, it is possible to efficiently manufacture.
[0174]
(8) As the torsion beam manufacturing apparatus 100B shown in FIG. 15 for example, each pulling the processing unit 120 may hold both ends of the torsion beam material W10.
　In this case, since the pull holding both ends of the torsion beam material W10 by a pair of tension processing unit 120, it is possible to impart a tensile force over the entire length of the torsion beam material W10. Therefore, it is possible to reduce or remove residual stress without omission over the entire length of the torsion beam material W10.
[0175]
(9) For example, as the torsion beam manufacturing apparatus 100B shown in FIG. 15, constant shape closed cross-section portion 11 and the press-forming the movable mold having a shape corresponding to the shape changing portion 12 131 (movable mold); the torsion beam material W10 constant for shape closed-section portion 11 and a shape changing part 12 a metal material tube before granting W0 (blank tube), the hydraulic cylinder 135 (second driving mechanism) for pressing the press-molding movable die 131 and; further comprising by a it may be.
　In this case, by pressing the press-molding movable die 131 to the metallic material tube W0 by a hydraulic cylinder 135, it is possible to obtain the torsion beam material W10 having a predetermined shape closed-section portion 11 and a shape changing part 12.
[0176]
(10) For example, as the torsion beam manufacturing apparatus 100C shown in FIG. 17, tensile at least one of the processing units 120 (each holding mechanism), the shape changing portion supporting the punch 122 to be inserted into the inside of the shape-changing portion 12 ( inner support member) and; second molding portion 132B for locking the outer shape changing portion 12 (the outer locking member); may be provided.
　In this case, in terms of supporting the inside of the shape changing portion 12 of the torsion beam material W10 in shape changing portion supporting the punch 122 can added tensile force of the second molding portion 132B is engaged on the outside of the shape changing portion 12 since, it is possible to provide an easy to tensile force while suppressing the deformation of the shape-changing portion 12.
[0177]
(11) For example, as the torsion beam manufacturing apparatus 100C shown in FIG. 17 may be employed the following configuration: press-molding movable die 132 (movable mold) is, corresponding to at least a predetermined shape closed-section portion 11 shaped a first mold portion 132A having a (movable mold body portion), and has a shape corresponding to at least the shape changing portion 12, a second mold provided to freely away from the first mold portion 132A 132B and (movable mold end), a hydraulic cylinder 132C (third driving mechanism) for separating the from the first mold portion 132A second mold 132B, comprises a; second mold 132B is, the outer engaging member also it serves as a.
　In this case, with respect to metal material pipes W0 (mother tube) which is pressed by the press-molding movable die 132, with giving the shape corresponding to at least a predetermined shape closed-section portion 11 by the first molding part 132A, the second mold 132B providing a shape corresponding to at least the shape changing portion 12. In state where the inserted shape changing portion supporting the punch 122 and the inner side of the shape changing portion 12 of the torsion beam material W10 was obtained, the addition was engaged the second mold 132B on the outer side of the shape changing portion 12, the torsion beam material W10 to add a tensile force. According to this configuration, since the second mold 132B also serves the outer locking member, it can be added as it continues to tensile force without transferring the torsion beam material W10 to other devices.
[0178]
(12) For example, as the torsion beam manufacturing apparatus 100D shown in FIG. 19, the third drive mechanism, the cam follower 133F (cam which is inserted into the gap between the ends of the first mold portion 132A and the second mold 132B ) it may be.
　In this case, first, processing in the torsion beam material W10 metallic material tube W0 is pressed by the first molding part 133A and the second mold portion 133B. Subsequently, by pushing the cam follower 133F in the gap, pushing the gap between the first mold portion 133A and the second forming unit 133B. Then, to move in a direction in which the second molding portion 133B from the first mold portion 133A away, by applying a tensile force to the torsion beam material W10, it is possible to reduce or remove residual stress.
[0179]
(13) For example, as the torsion beam manufacturing apparatus 100C shown in FIG. 17 may be employed the following configuration: a torsion beam press forming fixed 110B for supporting the material W10 (supporting die) further comprising a; press forming fixed mold 110B has a torsion beam material W10, constant shape closed cross-section portion 11 first supporting portion 111B for supporting the portion containing the (supporting mold body portion), cutlet rotatably provided apart from the first support portion 111B comprises a second supporting portion 112B for supporting at least the shape-changing portion 12 (supporting mold end), the.
　In this case, when applying a tensile force to the torsion beam material 10, since the second support portion 112B can be freely spaced from the first support portion 111B, it does not inhibit the extension of the torsion beam material W10 associated with tension. Therefore, since the tensile force can be applied to ensure the torsion beam material W10, it can be reduced or removed reliably residual stress.
[0180]
(14) In the above embodiments, it may be employed the following configuration: further comprising a control unit for controlling the hydraulic cylinder 125; the control unit operates the hydraulic cylinder 125, at least the connection of the torsion beam material W10 distortion of 1% or more in the longitudinal direction given to parts 12A.
　In this case, it is possible to impart sufficient tensile strength to cause eliminate or reduce residual stresses in the torsion beam material W10.
Industrial Applicability
[0181]
　According to the torsion beam manufacturing method and torsion beam manufacturing apparatus according to the present invention, it is possible to produce a torsion beam that has fatigue properties superior efficiently, the industrial applicability is large.
DESCRIPTION OF SYMBOLS
[0182]
　10 torsion beam
　11 fixed shape closed-section portion
　12 shaped changing part
　12A connecting portions (connecting
　region) 100, 100A, 100B, 100C, 100D torsion beam manufacturing apparatus
　110B press forming fixed (supporting
　mold) 111B first support portion (support mold body
　portion) 112B second supporting portion (supporting mold
　end) 120, 120A, 120B tensile processing unit (holding
　mechanism) 121B, 121C clamp member (holding portion)
　122 shape change portion supporting the punch (inner support
　member) 125 hydraulic cylinder (first driving
　mechanism) 131, 132 and 133 press-molding movable die (movable
　mold) 132A first mold portion (movable mold body
　portion) 132B second molding part (outer locking member, movable mold ends)
　133F cam follower (third driving mechanism, a
　cam) 135 hydraulic cylinder (second drive
　mechanism) 121 The upper outer holder (outer locking
　member) 1212 lower outer holding portion (the outer support
　member) W0 metallic material tube (mother
　tube) W10 torsion beam Material

claims

A constant shape closed cross-section portion is a closed cross-section of substantially V-shaped or substantially U-shaped, wherein the predetermined shape closed continuous to face and the closed cross-section are different cross section perpendicular to the longitudinal direction at any position in the longitudinal direction and shape change portion having a connection region having a closed cross section shape, a method of manufacturing a torsion beam having a
　least the connection of the torsion beam material said predetermined shape closed-section portion and wherein the shape changing part is formed regions to have the longitudinal direction to obtain a tensile force added the torsion beam along the tensile step
torsion beam manufacturing method characterized by.
[Requested item 2]
　The tensile step, and supports the inner of the outer portion along the longitudinal direction than the connection region with the inner support member, in a state where the outer engagement member to engage with the outside of the outer portion, said inner support member and the outer engaging member is moved in a direction away from said predetermined shape closed-section portion, applying said pulling force
torsion beam method according to claim 1, characterized in that.
[Requested item 3]
　In the tension step,
　　the outside of the connection region is supported by outer support member,
　　the inner support member and moved with and synchronously in the same direction of the outer engaging member moves the outer support member
and wherein the torsion beam method according to claim 2.
[Requested item 4]
　The tensile step, the torsion beam material between both ends by making relatively spaced along said longitudinal, applying said pulling force over the entire length of said torsion beam material
torsion beam production according to claim 1, characterized in that Method.
[Requested item 5]
　The tension in the process, imparts the distortion of 1% or more in the longitudinal direction at least with respect to the connection region of the torsion beam material
torsion beam manufacturing method according to any one of claims 1 to 4, characterized in that.
[Requested item 6]
　The tension before the step, the blank tube is pressed with a press to obtain the torsion beam material
torsion beam manufacturing method according to any one of claims 1 to 5, characterized in that.
[Requested item 7]
　Different cross section perpendicular to the longitudinal direction at any position in the longitudinal direction and fixed shape closed cross-section portion is a closed cross-section of substantially V-shaped or substantially U-shaped, and the constant shape closed cross-section portion into continuous with and said closed cross section an apparatus for manufacturing a torsion beam having a shape changing part, the having a connection region having a closed cross section shape
　of the torsion beam material said predetermined shape closed-section portion and the shape change portion is formed, the torsion beam material ; a portion of the well one side than the connection area when viewed along a longitudinal direction, a pair of holding mechanisms for holding the part on the other side than the connection area of the
　relative between the respective holding mechanisms ; a first driving mechanism for separating the
comprises a
torsion beam manufacturing apparatus characterized by.
[Requested item 8]
　Each retaining mechanism holds the both ends of the torsion beam material
torsion beam manufacturing apparatus according to claim 7, characterized in that.
[Requested item 9]
　The constant shape closed-section portion and the movable mold and having a shape corresponding to the shape changing portion;
　with respect to the predetermined shape closed-section portion and mother tube before applying the shape change unit to said torsion beam material, the movable mold ; and a second drive mechanism for pressing the mold
further comprising a
torsion beam manufacturing apparatus according to claim 8, characterized in that.
[Requested item 10]
　Wherein at least one of the holding mechanism,
　　and the inner support member to be inserted inside the shape-changing portion;
　　; and the outer engaging member for engaging the outside of the shape-changing portion
comprises
claims, characterized in that the torsion beam manufacturing apparatus according to claim 7.
[Requested item 11]
　The constant shape closed-section portion and the movable mold and having a shape corresponding to the shape changing portion;
　with respect to the predetermined shape closed-section portion and mother tube before applying the shape change unit to said torsion beam material, the movable mold ; and a second drive mechanism for pressing the mold
further comprising a
torsion beam manufacturing apparatus according to claim 10, characterized in that.
[Requested item 12]
　The movable mold,
　　and the movable mold body having a shape corresponding to at least the predetermined shape closed cross-section portion,
　　and has a shape corresponding to at least the shape changing portion, relative to the movable mold body portion and spaced freely provided a movable mold end,
　　and a third driving mechanism for separating the movable mold ends from the movable mold body portion,
a provided;
　the movable mold ends, said outer engagement also it serves as a stop member;
that torsion beam manufacturing apparatus according to claim 11, wherein.
[Requested item 13]
　The third drive mechanism is a cam which is inserted into a gap between the movable mold body part and the movable mold ends
torsion beam manufacturing apparatus according to claim 12, characterized in that.
[Requested item 14]
　The torsion beam further comprises a support die for supporting the material;
　the support mold,
　　the torsion beam material, a support mold body portion that supports the portion including the predetermined shape closed cross-section portion,
　　the supporting mold body portion and provided freely spaced for, and a least a support mold end portion supporting the shape changing part;
it torsion beam manufacturing apparatus according to any one of claims 7 to 13, wherein.
[Requested item 15]
　Further comprising a control unit for controlling said first driving mechanism;
　wherein the control unit, the first by operating the drive mechanism, the longitudinal direction of 1% or more with respect to the torsion beam material of at least the connection region imparting strain;
that torsion beam manufacturing apparatus according to any one of claims 7 to 14, wherein.