JP2012111377A - Cross member for metal vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cross member for metal vehicle, which is capable of reducing expansion and contraction of metal lumbers, and capable of achieving moldability and lightweight, without complicating a mold structure of a press device.SOLUTION: The cross member 20 bent in a saddle type includes: a web 22; a pair of sidewalls 24 and 26 stood from both side edges in the width direction of the web 22; flanges 28 and 30 which overhang in the direction mutually estranged from the pair of the sidewalls 24 and 26. Cross member 20 ranges from both ends in the longitudinal direction of the web 22, to a folding part 23 of the web 22 respectively, and the web 22 is formed so that the width direction length of the web 22 may become gradually long.

Description

  The present invention relates to a cross member for a metal vehicle.

  2. Description of the Related Art Conventionally, a metal vehicle cross member (hereinafter simply referred to as a cross member) used in an automobile body is constructed so as to connect a pair of side members 50 shown in FIG. In recent years, the floor of an automobile has been reduced by arranging the side members 50 low. Therefore, in order to secure the propeller shaft 60 located at the lower part of the vehicle body or the fuel tank arrangement space SP, a cross member having an intermediate portion bent in a bowl shape is used.

  As shown in FIG. 12, the cross member bent into a bowl shape is formed to project from the web 10, a pair of side walls 12, 14 erected in the same direction from both side edges of the web 10, and the ends of the side walls 12, 14. The flange portions 16 and 18 are formed. The cross member is formed by press-molding a metal material so that the cross section is formed into a so-called hat shape, and the central portion in the longitudinal direction is bent into a bowl shape.

However, when the cross member is simply press-molded into a bowl shape, there are the following problems.
(1) As shown in FIG. 12 (a), a wrinkle 15 is formed in the central portion in the longitudinal direction of the web 10, and the longitudinal central portions of both side walls 12, 14 as shown in FIG. 12 (b). A horizontal wrinkle 13 is formed as a surplus.

(2) A large warp (elongated flange) is formed at the center in the longitudinal direction of both side walls 12 and 14.
(3) Sharpness is formed at the ends of the flange portions 16 and 18 at the center in the longitudinal direction.

(4) A spring back in the transverse direction (web width direction) and a spring back in the longitudinal direction of the web are generated.
Therefore, various proposals have been made to solve the above problems. In Patent Documents 1 and 2, when forming a cross member using a punch and a die, a cross-sectional peripheral length is around at least one of a ridge line portion formed by the web and the side wall and a corner portion formed by the side wall and the flange portion. A shorter fillet is formed. By forming the fillet portion, the tensile stress generated at the time of molding is relieved to prevent a decrease in dimensional accuracy of the three-dimensional shape due to springback, twisting, and the like.

  In Patent Documents 3 and 4, the cross member is molded by a two-stage breath molding method. In this case, the shoulder radius of the punch used in the first stage molding is larger than the shoulder radius of the punch used in the second stage molding, that is, the shoulder radius of the shoulder portion (bent portion between the web and the side wall) of the final product. Form. By this molding method, warpage due to the spring back in the longitudinal direction of the web is prevented.

  In Patent Document 5, a high-strength steel plate is sandwiched between a punch and a counter holder, and the end of the high-tensile steel plate protruding from these is given a bending in the opposite direction to the spring back by a lateral movement of a horizontal slide die. The spring back generated in the step of bending to a predetermined bending angle is offset with the bending bend to prevent the spring back.

  Patent Document 6 discloses a press die in which a bead is formed at a part of a work that is predicted to generate a large stress, and the bead is extended when the work is formed in a U-shaped cross section. Yes.

  In Patent Document 7, while pressing the die-side pad against the workpiece while the punch-side pad protrudes outward from the pressing surface of the punch, the workpiece is press-formed between the die and the punch, It is disclosed that the workpiece is press-molded until the punch-side pad is at the same height as the pressing surface of the punch at the molding bottom dead center. With this configuration, it is possible to prevent shape defects such as a change in angle due to a spring back and a ridge line warp (surface warp).

JP 2009-202189 A JP 2009-248087 A JP 2008-73697 A JP 2007-21568 A JP-A-6-246355 JP-A-6-154897 JP 2010-82660 A

  However, in Patent Documents 1 and 2, although the problem (4) can be solved, the problems (1), (2), and (3) are not proposed. Since the methods of Patent Documents 3 and 4 are two-stage press molding, two types of punches with different shoulder shapes are necessary and molding is performed in two stages, so that molding takes time and mold costs Becomes larger. Patent Document 5 has a problem that the configuration of the mold is complicated because a horizontal slide die is required.

  Patent Document 6 requires a member such as a bead forming member and an upper member for bead forming in order to form a bead, and there is a problem that the mold structure is complicated. Moreover, in patent document 7, there exists a problem which a punch side pad becomes an essential structure and a metal mold | die structure becomes complicated.

  The present invention provides a cross member for a metal vehicle that can reduce the expansion and contraction of the metal material without complicating the mold structure of the press device, and can achieve formability and weight reduction. It is in.

  In order to achieve the above object, the invention of claim 1 is directed to a web extending in a longitudinal direction, a pair of side walls erected from both side edges in the width direction of the web, and a direction away from the pair of side walls. A metal vehicle cross member that includes a flange portion that is formed in an overhang and is bent in a bowl shape in the longitudinal direction of the web, and is formed at each of the folded portions of the web from both ends in the longitudinal direction of the web. The gist of the cross member for a metal vehicle is that the web is formed so that the length in the width direction of the web gradually increases.

  According to a second aspect of the present invention, in the first aspect, the side edge of the web is formed in a linear shape, a curved shape, or a broken line shape from each end in the longitudinal direction of the web to a bent portion of the web. It is characterized by.

According to a third aspect of the present invention, in the first or second aspect, the bent portion of the web is a central portion of the web.
According to a fourth aspect of the present invention, in any one of the first to third aspects, the side walls are bent at a bent portion of the web, the bending angle of the bent portion of the web, and The folding angle of both side walls is equal.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, when one of the side walls is a first side wall and the other is a second side wall, the first side wall and the second side wall At each end portion in the longitudinal direction, the front end on the flange portion side is formed so as to be wider than the base end on the web side.

  A sixth aspect of the invention is characterized in that in any one of the first to fifth aspects, the invention is made of a high-tensile steel plate.

  According to the first aspect of the present invention, the mold structure of the press device is formed by forming the web so that the length in the width direction of the web gradually increases from both ends in the longitudinal direction of the web to the bent portions of the web. It is possible to obtain a shape that suppresses the expansion and contraction of the material without making it complicated. For this reason, there is an effect that the expansion and contraction of the metal material can be reduced and the moldability and the weight can be reduced.

  According to the invention of claim 2, even if the side edge of the web is formed in a straight line shape, a curved line shape or a broken line shape from each end portion in the longitudinal direction of the web to the bent portion of the web, the effect of the first aspect is achieved. Play.

According to the invention of claim 3, even when the bent portion of the web is the central portion of the web, the effect of claim 1 is obtained.
According to a fourth aspect of the present invention, the side walls are bent at the bent portion of the web, and the geometric angle is obtained by making the bent angle of the bent portion of the web equal to the bent angle of the both side walls. In addition, the shape in which the expansion and contraction of the material is most suppressed can be obtained.

  According to the invention of claim 5, at each end portion in the longitudinal direction of the first side wall and the second side wall, the front end on the flange portion side is formed to be wider than the base end on the web side. The thrust strength can be improved.

  According to invention of Claim 6, the effect of Claim 1 is easily realizable in a high-tensile steel plate.

The perspective view in the use condition of the cross member for metal vehicles of one Embodiment. The perspective view of the cross member for metal vehicles of one Embodiment. The schematic sectional drawing of the press apparatus of one Embodiment. The schematic sectional drawing of the press apparatus in the bending process of one Embodiment. (A), (b) is explanatory drawing which shows the press operation of a punch and a counter holder. The schematic top view of die | dye and a counter holder. (A) is a side view of the cross member for metal vehicles of one embodiment, (b) is a top view of the cross member for metal vehicles of one embodiment. The perspective view of the cross member for metal vehicles of other embodiment. (A) is a perspective view of the cross member for metal vehicles of other embodiment, (b) is also a side view, (c) is also a top view. (A) is a perspective view of the cross member for metal vehicles of other embodiment, (b) is also a side view, (c) is also a top view. (A) is a top view of the cross member for metal vehicles of other embodiment, (b) is a side view similarly. (A) is a top view of the conventional cross member for metal vehicles, (b) is a side view similarly.

  Hereinafter, an embodiment in which a metal vehicle cross member (hereinafter simply referred to as a cross member) of the present invention is embodied will be described with reference to FIGS. In addition, the same code | symbol shall be attached | subjected about the same structure as the structure demonstrated in the prior art example.

As shown in FIG. 1, the cross member 20 is used by being connected by welding between a pair of side members 50 extending in the front-rear direction of the body of the automobile.
As shown in FIGS. 2, 7 (a) and 7 (b), the cross member 20 is formed into a saddle shape by bending a central portion in the longitudinal direction by press-forming a high-tensile steel plate as a metal material. ing. More specifically, the web 22 of the cross member 20 extends in a flat plate shape in the longitudinal direction, and a bent portion 23 is formed at the center in the longitudinal direction by the press molding. The bending angle θ of the bending portion 23 is an obtuse angle as shown in FIG.

  Further, as shown in FIGS. 2 and 7B, the web 22 is formed so that the width direction gradually increases linearly from both ends in the longitudinal direction toward the bent portion 23 in the central portion. That is, the length of the web 22 in the width direction gradually increases from the end toward the bent portion 23. For this reason, the side edges 22a and 22b of the web 22 are linearly formed from the end portion to the bent portion 23. In the present embodiment, the pair of side edges 22a and 22b positioned in the width direction of the web 22 are formed so as to be line symmetric with respect to a center line L extending in the longitudinal direction when viewed in plan. . That is, as shown in FIG. 7B, the angle α1 of the left and right side edges 22a located so as to sandwich the bent portion 23 is formed to be an obtuse angle.

  Further, as shown in FIG. 7B, the angle α2 of the left and right side edges 22b positioned so as to sandwich the bent portion 23 is formed to be an obtuse angle. In the present embodiment, α1 and α2 have the same angle. In this embodiment, θ = α1 = α2.

  From both side edges of the web 22, a pair of side walls 24, 26 are erected in a direction orthogonal to the web 22 in a direction opposite to the bending direction of the web 22. Bending portions 24 a and 26 a are formed at the center in the longitudinal direction of the side walls 24 and 26 so as to be continuous with the bending portion 23. Flange portions 28 and 30 are projected from the ends of the side walls 24 and 26 in a direction perpendicular to the direction in which the side walls are erected and away from each other. In the flange portions 28 and 30, bent portions 31 and 32 are formed at the center in the longitudinal direction. In the present embodiment, the vertical width (height) of the side walls 24 and 26 from the web 22 has the same width over the entire longitudinal direction.

  And since the web 22, the side walls 24 and 26, and the flange parts 28 and 30 are formed as mentioned above, the cross member 20 is formed in what is called a hat-shaped cross section.

(About press equipment)
Next, a press apparatus for press-molding the cross member 20 will be described with reference to FIGS.

  As shown in FIG. 3, in the press apparatus, a die 73 is fixed to a lower mold 72 fixed to a bed (not shown). A counter holder 76 supported by a cushion 75 is provided in the machining hole 74 of the die 73 so as to be able to appear and retract. As shown in FIG. 6, on the upper surface 77 of the counter holder 76, a top portion 78 for forming the bent portion 23 of the web 22 and a pair of presses descending obliquely in the opposite directions across the top portion 78. Surfaces 79 and 80 are provided. The angle between the pair of press surfaces 79 and 80 is θ. A bent shoulder 81 is provided at the entrance of the processing hole 74.

  As shown in FIG. 6, on the upper surface 82 of the die 73, a pair of portions sandwiching the upper opening of the processing hole 74 is a pair of top portions 83 for forming the bent portions 31 and 32. In addition, the upper surface 82 of the die 73 has a pair of press surfaces 84 and 85 that are inclined downward in opposite directions with the top portion 83 interposed therebetween. The angle between the pair of press surfaces 84 and 85 is θ.

  A punch 86 is fixed to the upper mold (not shown) so as to face the counter holder 76. The punch 86 has a size and a cross-sectional shape corresponding to the machining hole 74 of the die 73. Further, as shown in FIGS. 5A and 5B, an inner top portion 87 and press surfaces 88 and 89 corresponding to the top portion 78 and the press surfaces 79 and 80 of the counter holder 76 are formed on the lower surface of the punch 86, respectively. ing.

  As shown in FIG. 3, a bending shoulder 90 for forming a bent portion that is a boundary between the web 22 and the side walls 24 and 26 is formed at the tip of the punch 86 in cooperation with the bending shoulder 81. Further, as shown in FIG. 3, a pair of shoulder portions 92 and 93 are formed at the base end portion of the punch 86. The shoulder portions 92 and 93 have shapes corresponding to the top portion 83 and the press surfaces 84 and 85 of the die 73 at the central portion in the longitudinal direction.

  When the cross member 20 is formed using the press device, as shown in FIG. 5A, the high-tensile steel plate K is formed by the counter holder 76 and the punch 86 positioned above the processing hole 74. While sandwiching and fixing, as shown in FIG. 5B, the high-tensile steel plate K is bent and formed at the center in the longitudinal direction by the press surfaces 79 and 88 and the press surfaces 80 and 89. The angle of the bent part is θ.

From the state of FIG. 5B, the upper mold (not shown) is lowered, and the high-tensile steel plate K held by the punch 86 and the counter holder 76 is lowered.
Then, when the descending punch 86 enters the processing hole 74 of the die 73, the portion that becomes the web 22 enters the processing hole 74 as it is in the high-tensile steel plate K, and the portions that become the side walls 24 and 26 are the side surface of the punch and the processing hole. It is drawn into the die 73 while being sandwiched by the inner surface of 74. At this time, sagging occurs in the central portion in the longitudinal direction of the portions that become the side walls 24 and 26. This sagging is controlled by the inner surface of the machining hole 74 and the side surface of the punch 86 by further lowering the punch 86, and is crushed by the time when the punch 86 reaches the bottom dead center. It is formed. Further, the flange portions 28 and 30 are formed by the shoulder portion 92 of the punch 86, the top portion 83 of the die 73, and the press surfaces 84 and 85 at the portion that becomes the flange portion of the high-tensile steel plate K.

  As described above, the cross member 20 whose cross section has a so-called hat shape is formed. After the press molding is completed, the upper die (not shown) is raised so that the cross member 20 is raised by the punch 86 and then removed from the punch 86.

(Function)
As shown in FIGS. 2 and 7B, the web 22 of the cross member 20 configured as described above gradually increases in width linearly from both ends in the longitudinal direction toward the bent portion 23 in the central portion. It is formed so that the direction spreads. By having the shape of the cross member 20 in this way, the cross member 20 can be formed without making the mold structure of the press apparatus complicated. In addition, as described above, the bending portions 23, 31, 32 are formed, that is, they are formed so as to have obtuse angles θ, α1, α2, thereby suppressing the expansion and contraction of the material. It can be shaped. For this reason, the expansion and contraction of the high-tensile steel plate K can be reduced, and the formability and weight can be reduced.

According to this embodiment, the following effects can be obtained.
(1) In the cross member 20 of the present embodiment, the web 22 is formed so that the length in the width direction of the web 22 gradually increases from both ends in the longitudinal direction of the web 22 to the bent portion 23 of the web 22. ing. As a result, it is possible to obtain a shape in which the expansion and contraction of the material is suppressed without complicating the mold structure of the press device.

  (2) Even if the side edge of the web 22 of the cross member 20 of the present embodiment is linearly formed from each end in the longitudinal direction of the web 22 to the bent portion 23 of the web 22, the effect of the above (1) can be obtained. Play.

(3) In this embodiment, even when the bent portion 23 of the web 22 is a cross member at the center of the web 22, the effect (1) is achieved.
(4) In the present embodiment, the side walls 24 and 26 are bent at the bending portion 23 of the web 22, and the bending angle θ of the bending portion 23 of the web 22 and the bending angle α 1 of the side walls 24 and 26 are set. By making α2 equal, it is possible to geometrically obtain a shape in which the expansion and contraction of the material is most suppressed.

  (5) Since the present embodiment is made of a high-tensile steel plate that is widely used as a material for the cross member, is it possible to reduce the expansion and contraction of the high-tensile steel plate and reduce formability and weight? it can.

In addition, this embodiment can also be changed and embodied as follows.
-In the said embodiment, although it was set as the high-tensile steel plate as a metal material, it is not limited to a high-tensile steel plate, Steel plates other than a high-tensile steel plate may be sufficient, and metal materials other than a steel plate may be sufficient. Good.

  In the embodiment, the pair of side edges 22a and 22b positioned in the width direction of the web 22 are formed so as to be line symmetric with respect to the center line L extending in the longitudinal direction when viewed in plan. However, the arrangement of the side edges is not limited to line symmetry. That is, although the angle α1 and the angle α2 are the same angle, the angle α1 and the angle α2 may be different as long as the obtuse angle is maintained. Even in this case, it is possible to obtain a shape in which expansion and contraction of the material is suppressed.

  Further, the angle α1 = the angle α2, and θ may be different from the angle α1, and the angles may be different as long as all of the angles maintain an obtuse angle. Even in this case, it is possible to obtain a shape in which the expansion and contraction of the material is suppressed.

  -In the said embodiment, although the height from the web 22 of the side walls 24 and 26 is made to have the same height over the whole longitudinal direction, the height from the web 22 of the side walls 24 and 26 is as follows. It is not necessary to have the same height over the entire longitudinal direction. The height may be lowered from the central portion in the longitudinal direction toward the end portion in the longitudinal direction, or may be increased in the opposite direction toward the end portion in the longitudinal direction. Good.

  As shown in FIG. 8, the side walls 24 and 26 at both ends in the longitudinal direction of the web 22 may be formed so that the distal end on the side opposite to the web is opened, that is, wider than the base end on the web side. Good. In this case, the side walls 24 and 26 on the center side in the longitudinal direction are formed so as to be orthogonal to the web 22 in the same manner as in the above-described embodiment, and the tip on the side opposite to the web is opened toward the end side in the longitudinal direction. It becomes slanted. If comprised in this way, when connecting the cross member 20 between the side members 50 and using it, side impact strength can be improved.

  -In the said embodiment, although the bending part 23 was formed only in one place in the center part of the longitudinal direction of the web 22, the place which provides a bending part is not limited to one place, Even if a bending part is provided in several places good. FIG. 9A is an example in which bent portions 23 a to 23 d are formed in order from the end R at a plurality of locations in the longitudinal direction of the web 22.

  In FIG. 9 (a), the bent portions 23b and 23c are respectively located proximal to the central portion in the longitudinal direction, and the width M1 of the region P1 between the bent portions 23b and 23c is a constant value. A region P2 between the bent portions 23b and 23a has a width M2 that becomes shorter toward the end R side. In the region P3 from the bent portion 23a to the end portion R, the width M3 is shortened toward the end portion R.

  In addition, the region P4 between the bent portions 23c and 23d is configured such that the width M4 becomes shorter toward the end S. A region P5 from the bent portion 23d to the end portion S is configured such that the width M5 becomes shorter toward the end portion S. In addition, each of the bent portions 23a to 23d is formed to have an obtuse bending angle θ1 to θ4 with respect to an adjacent region.

The side walls 24 and 26 and the flange portions 28 and 30 are formed with bent portions corresponding to the bent portions 23a to 23d of the web 22, respectively.
When formed in this way, as shown in FIG. 9C, the side edge of the web 22 is formed in a polygonal line shape. Even if comprised in this way, there can exist an effect similar to the said embodiment.

  -As shown in FIG. 10, in the said embodiment, although the bending site | part 23 was formed only in one place in the center part of the longitudinal direction of the web 22, the place which provides a bending site | part is formed so that it may have a broken line clearly. It is not limited and may be formed to be curved. In FIG. 10, the web 22 of the cross member 20, the side walls 24 and 26, and the center portions in the longitudinal direction of the flange portions 28 and 30 are curved so as to have a rounded shape. The region of the curved portion becomes the bent portion 95.

  In this case, as shown in FIG. 10B, the angle θ at which the tangent lines extending from the flat portion of the web 22 adjacent to the bent bending portion 95 intersect each other is the bending angle. This angle θ is an obtuse angle.

  Further, as shown in FIG. 10 (c), at the bent portions of the side walls 24 and 26 corresponding to the bent bent portion 95, the angles α1 and α2 at which the tangent lines extending from the flat portions adjacent to the bent portions intersect are bent. It becomes an angle. These angles α1 and α2 are obtuse angles. The relationship between θ, α1, and α2 may be any relationship already described in other embodiments.

  -In above-mentioned embodiment, although the bending site | part 23 of the web 22 was provided in the center part of the longitudinal direction, the bending site | part 23 is not limited to a center part. For example, as shown in FIGS. 11A and 11B, the bent portion 23 of the web 22 may be formed at a position deviated from the central portion to one end side.

θ, α1, α2, θ1-θ4 ... bending angle,
K: high-tensile steel plate, R, S: end,
22 ... Web, 22a, 22b ... Side edge,
23, 23a to 23d, 24a, 26a, 31, 32, 95 ... bent portions,
24, 26 ... sidewalls, 28, 30 ... flanges.

Claims (6)

A longitudinally extending web, a pair of side walls erected from both side edges in the width direction of the web, and a flange portion formed to project from the pair of side walls in a direction away from each other, in the longitudinal direction of the web, The web is a metal vehicle cross member bent into a saddle shape,
A cross member for a metal vehicle, wherein the web is formed so that the length in the width direction of the web gradually increases from both ends in the longitudinal direction of the web to the bent portion of the web. .   2. The metal side edge according to claim 1, wherein the side edge of the web is formed in a straight line shape, a curved line shape, or a broken line shape from each end portion in the longitudinal direction of the web to a bent portion of the web. Cross member for vehicles.   The metal vehicle cross member according to claim 1, wherein the bent portion of the web is a central portion of the web. The both side walls are bent at the bent portion of the web,
The metal vehicle cross member according to any one of claims 1 to 3, wherein a bending angle of a bent portion of the web is equal to a bending angle of the both side walls.   When one of the side walls is a first side wall and the other is a second side wall, the flange side end is wider than the web side base end at each longitudinal end of the first side wall and the second side wall. 5. The metal vehicle cross member according to claim 1, wherein the metal vehicle cross member is formed as described above.   The metal vehicle cross member according to any one of claims 1 to 5, wherein the cross member is made of a high-tensile steel plate.

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