JP5407295B2 - Press-molded product, press-molded product manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to a press-formed product, a method for manufacturing a press-formed product, and a manufacturing apparatus.

A press-formed product having a U-shaped cross section that is applied to a vehicle suspension component or the like is manufactured from a tailored blank (see, for example, Patent Document 1). A tailored blank is formed by previously joining and integrating two dissimilar steel plates, and one of the dissimilar steel plates is made of a thick steel plate and applied to a local site that requires rigidity or strength. The other of the steel plates is made of a thin steel plate and is applied to a portion where rigidity or strength is relatively not required.
JP 2005-152975 A

  Since one of the dissimilar steel plates is made of a thin steel plate, it is possible to reduce the weight of the press-formed product having a U-shaped cross section, but there is a problem in manufacturing cost. That is, since joining of dissimilar steel plates is performed by welding the butt portions of dissimilar steel plates, high butt accuracy is required, and it is difficult to improve productivity, leading to an increase in manufacturing cost.

  The present invention has been made to solve the problems associated with the above-described prior art, and aims to reduce the weight and the manufacturing cost of a U-shaped cross-section press-formed product.

The uniform phase of the present invention for achieving the above object is a method of manufacturing a U-shaped cross-section component by press molding, and includes a preparation step, an arrangement step, a bending step, and a thickening step. In the preparation step, a U-shaped cross-section preform having a pair of spaced apart side wall portions and an arcuate connection wall portion that connects the end portions of the side wall portions is prepared. In the placement step, the preform is placed in a mold. In the bending step, the connecting wall portion is bent with respect to a part in the extending direction of the U-shaped cross section by pressing the preform with the mold during the mold clamping operation of the mold. In the thickening step, the bent portion is compressed and pushed by the molding die to generate a material flow, and the thickness of the side wall portion and the connecting wall portion in the portion is clamped. Increase compared to the plate thickness before operation. Further, the preformed body prepared in the preparation step has a pushing portion arranged on a free end side positioned opposite to the connecting wall portion side in the side wall portion of the part, and in the bending step The pushing portion is pushed toward the connecting wall portion side, and the material of the pushing portion is caused to flow to bend the connecting wall portion, and the bent portion is compressed and pushed in the thickness increasing step. Thus, a material flow is generated in the bent portion, and the thickness of the side wall portion and the connecting wall portion is increased by the material fed from the pushing portion to the connecting wall portion.

Another aspect of the present invention for achieving the above object is a press-formed product comprising a U-shaped cross-section part manufactured by the above-described method .

Another aspect of the present invention for achieving the above object is an apparatus for manufacturing a U-shaped cross-section part by press molding, wherein a pair of spaced apart side wall portions and the end portions of the side wall portions are connected to each other. A preform having a U-shaped cross-section having an arc-shaped connecting wall for connecting the two has a forming die that is placed and clamped. The mold includes a punch portion disposed inside the preform, and a die portion that presses the outer surface of the preform toward the punch portion by relative movement with the punch portion. The sectional thickness of the cavity formed by the punch portion and the die portion at the time of mold clamping is set to be larger than the plate thickness of the preform with respect to a part in the extending direction of the U-shaped section. Therefore, the punch portion and the die portion are bent during the mold clamping operation by bending the connecting wall portion with respect to a part in the extending direction of the U-shaped cross section by pressing the preform. By compressing and pushing the portion that has been bent, a material flow is generated in the bent portion, and the plate thickness of the side wall portion and the connecting wall portion in the part is set to the plate thickness before the mold clamping operation. Compare and increase. And the said preforming body has the pushing part arrange | positioned at the free end side located on the opposite side of the connection wall part side in the said one part side wall part, The said punch part is in the middle of mold clamping operation | movement By pushing the pushing portion toward the connecting wall portion, the material of the pushing portion is caused to flow, thereby increasing the plate thickness of the side wall portion and the connecting wall portion.

According to the method and apparatus relating to the uniform phase and another uniform phase of the present invention, the plate thickness of the side wall portion and the connecting wall portion in a part in the extending direction of the U-shaped cross section is the plate thickness of the corresponding portion in the preform. Increased press-formed products (parts) are manufactured compared to The increase in the thickness of the side wall portion and the connecting wall portion is based on the material fed from the pushing portion to the connecting wall portion, and the pushing portion protrudes from the free end side of the side wall portion. It is easy to install. Since the rigidity or strength of the press-formed product is ensured by the portion where the plate thickness is increased, it is possible to easily reduce the weight of the press-formed product. Moreover, since the said part where the plate | board thickness is increasing is formed by the press molding which has favorable productivity compared with the tailored blank to which butt welding is applied, manufacturing cost is reduced. Therefore, it is possible to reduce the weight and the manufacturing cost of the press-formed product having a U-shaped cross section.

  According to the press-formed product according to another uniform phase of the present invention, the plate thickness of the side wall portion and the connecting wall portion in a part in the extending direction of the U-shaped cross section is compared with the plate thickness of the corresponding portion in the preform. The thickness of the portion where the thickness is increased and the thickness is increased is larger than the thickness of the peripheral portion of the portion. Since the rigidity or strength of the press-formed product is secured by the portion where the plate thickness is increased, it is possible to easily reduce the weight of the press-formed product. Moreover, since the site | part where the plate | board thickness is increasing is formed by press molding which has favorable productivity compared with the tailored blank to which butt welding is applied, manufacturing cost is reduced. Therefore, it is possible to reduce the weight and the manufacturing cost of the press-formed product having a U-shaped cross section.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a perspective view for explaining a press-formed product according to Embodiment 1, FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. It is.

  The press-formed product (part) 120 according to Embodiment 1 is a long object having an open cross section, has a U-shaped cross section, and a pair of side walls 124 spaced apart from each other, and ends of the side walls 124. Are obtained by press-molding a blank (preliminary molded body). The side wall part 124 and the connecting wall part 126 are connected continuously and smoothly. The length of the press-formed product 120 along the longitudinal direction Y (the direction in which the U-shaped cross section extends) is the length in the circumferential direction P intersecting the longitudinal direction Y (the total length of the side wall portion 124 and the connecting wall portion 126). Bigger than.

  The plate thickness of the side wall portion 124 and the connecting wall portion 126 at the central portion (part in the extending direction of the U-shaped cross section) 136 of the press-formed product 120 in the longitudinal direction Y is compared with the plate thickness before press forming by press forming. Has been increased. The plate thickness of the side wall portion 124 and the connecting wall portion 126 at the end portions (peripheral portions) 132 and 138 is the same as the plate thickness before press molding. That is, the plate thickness of the side wall portion 124 and the connection wall portion 126 at the central portion 136 is larger than the plate thickness of the side wall portion 124 and the connection wall portion 126 at both end portions 132 and 138.

  Since the rigidity or strength of the press-formed product 120 is secured by the portion where the plate thickness is increased (the side wall portion 124 and the connecting wall portion 126 in the central portion 136), the press-formed product 120 can be easily reduced in weight. Is possible. In addition, since the portion where the plate thickness is increased is formed by press molding having good productivity as compared with the tailored blank to which butt welding is applied, the press-molded product 120 is reduced in manufacturing cost. . Therefore, it is possible to reduce the weight and the manufacturing cost of the press-formed product having a U-shaped cross section.

  The hardness of the portion where the plate thickness is increased is larger than the hardness of the peripheral portion (the side wall portion 124 and the connecting wall portion 126 at both end portions 132 and 138) due to work hardening (compressive stress) by press molding. Therefore, it can be applied to uses that require hardness.

  The side wall portions 124 are positioned substantially parallel to each other, but are not particularly limited to this configuration. The shape of the press-formed product 120 in the longitudinal direction Y is not limited to a linear shape, and may have a curved portion curved in the longitudinal direction. The shape of the bending portion is, for example, an L shape, a C shape, an acute angle shape, or a gentle arc shape.

  FIG. 4 is a plan view for explaining a suspension component to which the press-formed product according to Embodiment 1 is applied.

  The suspension component 140 has an upper side member and a lower side member that have a hollow cross section and whose edges are welded to each other. The upper side member and the lower side member are long objects having an open cross section, and by applying the press-formed product 120, it is possible to reduce the weight of the suspension component 140 and reduce the manufacturing cost. Since the press-formed product 120 has improved rigidity or strength of the central portion 136, for example, when fixing a bracket for fastening another part such as an arm, it is possible to ensure good fixing strength. . In particular, when welding is applied to fixing, fatigue strength is improved, which is preferable. In addition, by directly fixing a nut as a fastening means to the central portion 136, the reinforcing plate arranged for improving the strength of the nut base is abolished, or a tapped hole is formed, and the nut Can be abolished or done.

  Next, the blank and press-formed product manufacturing apparatus according to Embodiment 1 will be described.

  5 is a perspective view for explaining the blank according to the first embodiment, FIG. 6 is a cross-sectional view for explaining the press-formed product manufacturing apparatus according to the first embodiment, and FIG. It is sectional drawing regarding line VII-VII.

  The blank 100 according to Embodiment 1 is preformed, for example, by press-molding a sheet-like rolled material in advance, and its shape substantially corresponds to the shape of the press-formed product 120, and is shown in FIG. As shown, it has a pair of side wall parts 104 which are spaced apart, and an arcuate connecting wall part 106 which connects the end parts of the side wall parts 104 to each other. The side wall part 104 and the connection wall part 106 are connected continuously and smoothly.

  A central portion (a part in the extending direction of the U-shaped cross section) 116 of the blank 100 has an extended portion (pushing portion) 114. The extension part 114 protrudes from the free end side located opposite to the connecting wall part side in the side wall part 104. The extended portion 114 constitutes a circumferential extended portion, and the cross-sectional peripheral length in the circumferential direction P at the central portion 116 is longer than the cross-sectional peripheral length in the circumferential direction P at both ends (peripheral portions) 112 and 118. As will be described later, the extended portion 114 is formed to easily generate a material flow that causes an increase in the plate thickness. The extended portion 114 protrudes from the free end side, and the extended portion 114 in the blank 100 is The perimeter of the cross section that is included is set longer than the perimeter of the cross section of the other part of the blank 100.

  The apparatus for manufacturing a press-formed product according to Embodiment 1 has a press-molding die for obtaining the press-formed product 120 from the blank 100. As shown in FIGS. 6 and 7, the press mold has an upper die (die portion) 160 and a lower die (punch portion) 170 that are arranged close to and away from each other, and a side die 180.

  The upper mold 160 has a U-shaped cavity surface corresponding to the outer surface shape of the press-formed product 120, and the cavity surface corresponds to the curved pressing portion corresponding to the connecting wall portion 126 and the side wall portion 124. Corresponding and having a vertical wall extending in the clamping direction X. The lower mold 170 is used for clamping the blank 100 between the upper mold 160 and has a cavity surface having a U-shaped cross section corresponding to the inner surface shape of the press-molded product 120 and a step portion 172. The lower mold cavity surface has a curved pressing portion corresponding to the connecting wall portion 126 and a vertical wall portion corresponding to the side wall portion 124 and extending in the mold clamping direction X. The pressing part and the vertical wall part are connected continuously and smoothly.

  The stepped portion 172 extends in the longitudinal direction Y, and is positioned so as to contact the extended portion 114 of the blank 100 and support the blank 100 when the blank 100 is disposed on the lower mold 170.

  At the time of mold clamping, the cross-sectional thickness of the cavity formed by the cavity surface of the upper mold 160 and the cavity surface of the lower mold 170 facing the central portion 116 of the blank 100 is larger than the plate thickness of the blank 100 and can be increased in thickness. It is set to become. On the other hand, the cross-sectional thickness of the cavity formed by the cavity surface of the upper mold 160 and the cavity surface of the lower mold 170 facing both the end portions 112 and 118 of the blank 100 matches the plate thickness of the blank 100, and the thickness increases. Not.

  The side mold 180 is positioned so as to come into contact with the end face 108 in the longitudinal direction Y of the blank 100, and is disposed on the side of the upper mold 160 and the lower mold 170. The side mold 180 is a restraining means for restraining the material flow in the longitudinal direction Y of the blank 100 by restraining the movement of the end face 108 when the mold is clamped and press-molded.

  Next, a method for manufacturing a press-formed product according to Embodiment 1 will be described.

  8, 9 and 10 are cross-sectional views for explaining the pushing process of the extension part, the formation of the bending part, and the disappearance of the bending part in the method for manufacturing a press-formed product according to the first embodiment.

  The manufacturing method of the press-formed product according to Embodiment 1 includes a preparation process, an arrangement process, a bending process, and a thickness increasing process.

  In the placement process, a blank 100 is prepared. In the arrangement process, the blank 100 is arranged between the upper mold 160 and the lower mold 170 (in the mold). In the bending process, in the middle of the mold clamping operation of the upper mold 160 and the lower mold 170, the blank 100 is pressed by the upper mold 160, whereby the connecting wall portion 106 in the blank central portion 116 is bent. In the thickening step, the bent portion (the connecting wall portion 106) is compressed and pushed by the upper die 160 and the lower die 170 to generate material flow, and the side wall portion 104 and the connecting wall at the blank central portion 116 are generated. The plate thickness of the portion 106 is increased compared to the plate thickness before the mold clamping operation.

  More specifically, first, the blank 100 is placed on the lower mold 170. The extended portion 114 protruding from the side wall portion 104 of the central portion 116 of the blank 100 abuts on the step portion 172 of the lower mold 170 (see FIG. 7). On the other hand, the side wall portions 104 at the both end portions 112 and 118 are separated from the step portion 172 of the lower mold 170 because they do not have the extended portion 114.

  When the upper die 160 is lowered toward the lower die 170 for clamping and press molding, the pressing portion of the upper die 160 comes into contact with the connecting wall portion 106 of the blank 100 arranged on the lower die 170. The clamping force of the upper mold 160 presses the expanded portion 114 of the blank 100 toward the stepped portion 172 of the lower mold 170, so that the expanded portion 114 supported by the stepped portion 172 of the lower mold 170 is deformed (see FIG. 8 (A) to (C)). The gap between the pressing portion of the upper mold 160 facing the connecting wall portion 106 and the pressing portion of the lower mold 170 is larger than the gap between the vertical wall portion of the upper mold 160 and the vertical wall portion of the lower mold 170 facing the side wall portion 104. Therefore, the material of the expanded portion 114 flows upward and is pushed in.

  Since the connecting wall portion 106 is in contact with the pressing portion of the upper mold 160, the force (flowing material) acting on the connecting wall portion 106 from the side wall portion 104 supported by the step portion 172 of the lower die 170 is connected. As shown in FIG. 9, the center portion of the wall portion 106 is bent toward the lower mold side (a curved portion is formed). The bending direction is the mold clamping direction X.

  Thereafter, the connecting wall 106 is sandwiched between the upper mold 160 and the lower mold 170 to compress the connecting wall 106 from the clamping direction X, and from the free end side of the side wall 104, thereby compressing the connecting wall 106. The curved portion of the portion 106 disappears, and the thickness of both the side wall portion 104 and the connecting wall portion 106 is increased by the material fed into the connecting wall portion 106, as shown in FIG. Since the pressing portion and the vertical wall portion of the upper mold 260 are continuously and smoothly connected, a part of the material fed into the connecting wall portion 106 is smoothly guided and returned toward the side wall portion side. It is.

  On the other hand, the extended portions 114 are not provided at both end portions 112 and 118 of the blank 100, and the cavity surface of the upper mold 160 and the cavity surface of the lower mold 170 corresponding to the both end portions 112 and 118 of the blank 100 are used. The cross-sectional thickness of the formed cavity matches the plate thickness of the blank 100. Therefore, no material flow occurs and the thickness is not increased.

  Then, the press-molded product 120 is obtained by completing the mold clamping. That is, the plate thickness of the connecting wall portion 106 and the side wall portion 104 in the central portion 116 of the blank 100 is increased compared to the plate thickness before press forming, and the connecting wall portion 126 and the side wall in the central portion 136 of the press-formed product 120. The part 124 is configured. The plate thickness of the connecting wall portion 106 and the side wall portion 104 at both end portions 112 and 118 of the blank 100 is the same as the plate thickness before press forming, and the both end portions 132 and 138 of the press-formed product 120 are configured as they are. .

  Since the rigidity or strength of the press-formed product 120 is ensured by the side wall portion 124 and the connecting wall portion 126 of the central portion 136 where the plate thickness is increased, the press-formed product 120 can be easily reduced in weight. is there. Moreover, since the side wall part 124 and the connection wall part 126 of the center part 136 where plate | board thickness is increasing are formed by press molding which has favorable productivity compared with the tailored blank to which butt welding is applied, Manufacturing costs are reduced. Therefore, it is possible to reduce the weight and the manufacturing cost of the press-formed product having a U-shaped cross section.

  The plate thickness of the side wall portion 124 and the connecting wall portion 126 of the central portion 136 is increased by pushing the expansion portion 114 disposed in the side wall portion 104 and causing the material to flow, so that it is easy to increase the thickness. It is. In addition, a lateral mold 180 is located on the side of the upper mold 160 and the lower mold 170. The side mold 180 abuts against the blank end face 108 and stops its movement. Since the material of the extended portion 114 is suppressed from flowing in the longitudinal direction Y of the blank 100, it mainly flows in the circumferential direction P. Therefore, it is possible to suppress a decrease in the thickness increasing efficiency.

  Next, modified examples 1 and 2 according to the first embodiment will be described.

  11 and 12 are a perspective view and a cross-sectional view for explaining Modification 1 according to Embodiment 1, and FIGS. 13 and 14 are perspective views for explaining Modification 2 according to Embodiment 1. FIG. And FIG.

  In the blank 100 shown in FIG. 11, the expanded portion 114 is disposed on the side wall portion 104 of both end portions 112 and 118, and the thickness of the side wall portion 124 and the connecting wall portion 126 at both end portions 132 and 138 is increased. A molded product 120 can be obtained. In this case, as shown in FIG. 12, the stepped portion 172 of the lower mold 170 supports both end portions 132 and 138 of the blank 100 during mold clamping.

  Further, in the blank 100 shown in FIG. 13, the extended portion 114 is disposed on the central portion 116 and the side wall portions 104 of the both end portions 112 and 118, and the side wall portion 124 and the connection at the central portion 136 and the both end portions 132 and 138. It is possible to obtain a press-formed product 120 in which the wall 126 has an increased plate thickness. In this case, as shown in FIG. 12, the stepped portion 172 of the lower mold 170 supports the central portion 116 and both end portions 132 and 138 of the blank 100 during mold clamping.

  As described above, according to the manufacturing method and the manufacturing apparatus according to the first embodiment, the plate thickness of the side wall portion and the connection wall portion in the central portion is increased as compared with the plate thickness of the corresponding portion in the preform. Press-formed products (parts) are manufactured. Since the rigidity or strength of the press-formed product is secured by the central portion where the plate thickness is increased, it is possible to easily reduce the weight of the press-formed product. Moreover, since the central part where the plate | board thickness is increasing is formed by press molding which has favorable productivity compared with the tailored blank to which butt welding is applied, manufacturing cost is reduced. Therefore, it is possible to reduce the weight and the manufacturing cost of the press-formed product having a U-shaped cross section.

  Since the blank extended portion protrudes from the free end side of the side wall portion, it is easy to flow the material.

  The lateral mold positioned to contact the longitudinal end surface of the blank suppresses the material of the extension from flowing in the longitudinal direction of the blank and mainly flows in the circumferential direction. Can be increased efficiently.

  In the press-formed product having a U-shaped cross section according to the first embodiment, the plate thickness of the side wall portion and the connecting wall portion in the central portion is increased as compared with the plate thickness of the corresponding portion in the blank, and The thickness of the portion where the thickness is increased is larger than the thickness of the end portions located on both sides of the central portion. Since the rigidity or strength of the press-formed product is secured by the central portion where the plate thickness is increased, it is possible to easily reduce the weight of the press-formed product. Moreover, since the central part where the plate | board thickness is increasing is formed by press molding which has favorable productivity compared with the tailored blank to which butt welding is applied, manufacturing cost is reduced. Therefore, it is possible to reduce the weight and the manufacturing cost of the press-formed product having a U-shaped cross section.

  Further, the hardness of the side wall portion and the connecting wall at the central portion where the plate thickness is increased is larger than the hardness of the side wall portion and the connecting wall at the end portion. This is because the hardness is increased by work hardening (compressive stress) by press molding, and can be applied to uses that require hardness.

  The portion where the plate thickness is increased is not limited to the central portion, and for example, the extended portion can be disposed at both end portions, or can be disposed only at one end portion. It is also possible to arrange a plurality of extended portions with a gap in the longitudinal direction of the blank. In this case, the press-formed product has a thickened portion arranged with a gap in the longitudinal direction.

  The plate thickness of the side wall portion and the plate thickness of the connecting wall portion are not limited to be the same. For example, the thickness of the side wall portion is made different by making the sectional thickness of the cavity different between the side wall portion and the connecting wall portion. It is also possible to make the thickness of the connecting wall portion different.

  The extension of the blank is not limited to the shape protruding from the free end side of the side wall of the adjacent peripheral part, but is positioned in the same plane or retreated (recessed shape) depending on the shape of the press-formed product ). In this case, the extended portion can be pushed in by providing a projecting portion in contact with the extended portion in the step portion of the lower mold.

  The size of the blank expansion portion is preferably set in consideration of the indentation ratio. The indentation ratio is obtained by reducing the cross-sectional circumferential length of the circumferential region in the portion where the plate thickness is increased by the cross-sectional circumferential length of the circumferential region in the peripheral portion of the portion, and further, in the portion corresponding to the portion in the press-formed product. It is a value divided by the circumferential length of the cross section of the direction area. That is, since the indentation ratio corresponds to the material flow rate, if the indentation ratio is set large, the effect of increasing the wall thickness is improved. However, if the indentation ratio is set too large, an excessively curved portion is formed during press molding. Since the curved portion is not extended and does not disappear, it causes buckling. Therefore, it is preferable to set the size of the extended portion so that the push-in ratio does not become excessive in order to avoid occurrence of buckling.

  Next, a second embodiment will be described.

  FIG. 15 is a cross-sectional view for explaining a press-formed product manufacturing apparatus according to Embodiment 2, and FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. In the following, members having the same functions as those in the first embodiment are denoted by similar reference numerals, and the description thereof is omitted to avoid duplication.

  The second embodiment is generally different from the first embodiment with respect to the configuration of the upper die, and a press-molded product manufacturing apparatus according to the second embodiment includes an upper die (die portion) 260, a lower die (punch portion) 270, and It has a side mold 280.

The upper mold 260 includes a through hole 262, a movable mold 264, a spring mechanism 266, and a stopper (restraining means) 268. The through hole 262 is positioned so as to face the connection wall portion 106 in the central portion 116 of the blank disposed in the lower mold 270. In addition, the extended part 114 supported by the level | step-difference part 272 of the lower mold | type 270 is arrange | positioned at the side wall part 104 connected with the said connection wall part 106. FIG.

  The movable mold 264 has a substantially rectangular block shape, is arranged so as to be able to protrude and retract from the through hole 262, and is located outside the blank. The pressing portion of the movable mold 264 corresponds to the connecting wall portion 126 of the press-formed product 120, has a curved shape, and has a sharp portion (edge of the curved end surface). The spring mechanism 266 is an urging force generating means used to urge the movable die 264 in a direction protruding from the through hole 262. The urging force of the movable mold 264 is set to a value that is smaller than the mold clamping force so as not to affect the mold clamping and that can plastically deform the blank. The spring mechanism 266 has a simple structure and is preferable. However, for example, an actuator or a hydraulic cylinder can be used instead.

  The stopper 268 is a restraining means for restraining the retraction of the movable mold 264 and is formed of a reduced diameter portion disposed in the through hole 262, and the diameter thereof is smaller than the diameter of the movable mold 264. The stopper 268 is set to position the movable mold 264 so that the pressing portion of the upper mold 260 including the pressing portion of the movable mold 264 forms a smooth cavity surface when the mold clamping is completed.

  Next, a method for manufacturing a press-formed product according to Embodiment 2 will be described.

  17 and 18 are cross-sectional views for explaining the formation of the bending portion and the disappearance of the bending portion in the method for manufacturing a press-formed product according to the second embodiment.

  When the upper mold 260 is lowered toward the lower mold 270 for clamping and press forming, the pressing portion of the movable mold 264 protruding from the through hole 262 of the upper mold 260 is a blank disposed on the lower mold 270. The connecting wall portion 106 abuts. Since the urging force of the movable mold 264 presses the blank expanded portion 114 toward the stepped portion 272 of the lower mold 270, it is expanded as in the case of FIGS. 8A to 8C according to the first embodiment. The part 114 is deformed. The gap between the pressing portion of the movable mold 264 facing the connecting wall portion 106 and the pressing portion of the lower mold 270 is greater than the clearance between the vertical wall portion of the upper mold 260 and the vertical wall portion of the lower mold 270 facing the side wall portion 104. Therefore, the material of the expanded portion 114 flows upward and is pushed in.

  The connecting wall portion 106 is separated from the pressing portion of the upper mold 260, but is in contact with the pressing portion of the movable mold 264, so that the connecting wall portion 106 extends from the side wall portion 104 supported by the step portion 272 of the lower mold 270. The force (flowing material) acting on 106 deflects the central portion of the connecting wall portion 106 toward the lower mold side (a curved portion is formed) as shown in FIG. That is, in the bending process, the movable wall 264 presses the connecting wall portion 106 to the lower mold side to promote the formation of the bending in the connecting wall portion 106. For this reason, even if it is a blank of a shape which is hard to bend, for example, since a connection wall part can be bent easily, it is possible to expand an application range.

  Thereafter, the connecting wall portion 106 is sandwiched between the movable mold 264 and the lower mold 270 so that the connecting wall portion 106 is compressed from the mold clamping direction X and is compressed from the free end side of the side wall portion 104. The curved portion of the portion 106 disappears, and the thickness of both the side wall portion 104 and the connecting wall portion 106 at the central portion 116 is increased by the material fed into the connecting wall portion 106 as shown in FIG. Further, since the pressing portion and the vertical wall portion of the upper mold 260 are continuously and smoothly connected, a part of the material fed into the connecting wall portion 106 is smoothly guided and returned toward the side wall portion side. It is.

  When the mold clamping is completed, the movable mold 264 is stopped by the stopper 268 and positioned so that the pressing part of the upper mold 260 including the pressing part of the movable mold 264 forms a smooth cavity surface. Accordingly, the pressing portion of the movable die 264 is curved and has a sharp portion (edge of the curved end surface), but constitutes a part of a smooth cavity surface. Therefore, the sharp portion of the movable die 264 This eliminates damage to the connecting wall 106, suppresses the occurrence of defects that form marks or depressions corresponding to the pressing portion of the movable mold 264, and improves the appearance quality of the part (press-molded product). it can.

  As described above, according to the second embodiment, for example, even a blank having a shape that is difficult to bend can be easily bent by pressing the movable wall. In addition, when the mold clamping is completed, the movable pressing portion forms a part of the smooth cavity surface, so that the connecting wall portion may be damaged by the movable sharp portion (the edge of the curved end surface). This eliminates the occurrence of defects that form traces or depressions corresponding to the movable pressing portion, and can improve the appearance quality of the part (press-molded product). Note that the first and second modifications according to the first embodiment can be incorporated into the second embodiment.

  Next, a third embodiment will be described.

  FIG. 19 is a cross-sectional view for explaining a press-formed product manufacturing apparatus according to Embodiment 3, and FIG. 20 is a cross-sectional view taken along line XX-XX in FIG.

  The third embodiment is generally different from the second embodiment with respect to the shape of the movable pressing portion. The manufacturing apparatus for the press-formed product (see FIG. 5) according to the third embodiment includes an upper die (die portion) 360, A lower die (punch portion) 370 and a side die 380 are provided.

  The upper mold 360 includes a through hole 362, a movable mold 364, a spring mechanism 366, and a stopper (restraining means) 368. The through-hole 362 is positioned so as to face the connecting wall portion 106 in the central portion 116 of the blank (see FIG. 5) disposed in the lower mold 370, and the side wall portion 104 connected to the connecting wall portion 106 includes An extension part 114 is arranged.

  The movable mold 364 has a distal end portion 365 having a flat pressing portion and a base portion that supports the distal end portion 365. The movable die 364 has a T-shaped cross section with respect to the longitudinal direction Y and is related to a direction L orthogonal to the longitudinal direction Y. Exhibits a rectangular cross section.

  The distal end portion 365 is arranged so as to be able to protrude and retract from the through hole 362, and the width in the longitudinal direction Y is smaller than the width of the base portion. Thereby, the material of the connecting wall portion 106 is prevented from flowing into the moving space of the movable mold 364. For example, when the thickness of the blank is 2 mm, the width of the tip portion 365 is preferably within 10 mm (5 times).

  Since the pressing portion of the distal end portion 365 of the movable mold 364 is flat and does not have a sharp portion, it is excluded that the connecting wall portion 106 is damaged by the movable mold 364, and a mark corresponding to the pressing portion of the movable mold 364 or Generation | occurrence | production of the malfunction in which a hollow part is formed is suppressed.

  The base of the movable mold 364 is a part to which the urging force (pressing force) from the spring mechanism 366 is transmitted, and the tip part 365 is a part to apply the transmitted urging force to the connecting wall part 106. In order to secure the function of promoting the formation of deflection in the connecting wall portion, the pressure receiving area to which the urging force is transmitted in the base portion is set to be larger than the pressure releasing area for applying the pressing force in the distal end portion 365.

  The spring mechanism 366 is a force generating means used to bias the distal end portion 365 of the movable die 364 in a direction protruding from the through hole 362. The urging force of the movable mold 364 is set to a value that is smaller than the clamping force so as not to affect the clamping and can plastically deform the blank.

  The stopper 368 is a restraining means for restraining the retraction of the movable mold 364, and includes a reduced diameter portion disposed in the through hole 362, and the diameter thereof is smaller than the diameter of the base portion of the movable mold 364. The stopper 368 is a plate whose cross-sectional thickness between the pressing portion against the connecting wall portion 106 at the distal end portion 365 of the movable die 364 and the pressing portion against the connecting wall portion 106 in the lower mold 370 is increased when the mold clamping is completed. It is set to match the thickness. Reference numeral 372 indicates a step portion of the lower mold 370 that contacts the blank extension portion 114.

  Next, a method for manufacturing a press-formed product according to Embodiment 3 will be described.

  FIGS. 21 and 22 are cross-sectional views for explaining the formation of the curved portion and the disappearance of the curved portion in the method for manufacturing a press-formed product according to the third embodiment.

  When the upper die 360 is lowered toward the lower die 370 for clamping and press molding, the flat pressing portion of the distal end portion 365 of the movable die 364 protruding from the through hole 362 of the upper die 360 is It abuts against a blank connecting wall portion 106 disposed on the mold 370. Since the urging force of the movable mold 364 presses the blank expansion portion 114 toward the stepped portion 372 of the lower mold 370, the urging force is expanded as in the case of FIGS. 8A to 8C according to the first embodiment. The part 114 is deformed. The gap between the pressing portion of the distal end portion 365 of the movable die 364 and the pressing portion of the lower die 370 that faces the connecting wall portion 106 is the vertical wall portion of the upper die 360 and the vertical wall portion of the lower die 370 that faces the side wall portion 104. Therefore, the material of the expansion part 114 flows upward and is pushed in.

  Although the connecting wall portion 106 is separated from the pressing portion of the upper mold 360, the connecting wall portion 106 is in contact with the pressing portion of the distal end portion 365 of the movable die 364, so that the force (flow) acting on the connecting wall portion 106 from the side wall portion 104. The material to be bent causes the central portion of the connecting wall portion 106 to bend toward the lower mold side (a curved portion is formed) as shown in FIG. In other words, in the bending process, the connecting wall portion 106 is pressed toward the lower mold side by the distal end portion 365 of the movable mold 364, thereby promoting the formation of the bending in the connecting wall portion 106. For this reason, even if it is a blank of a shape which is hard to bend, for example, since a connection wall part can be bent easily, it is possible to expand an application range.

  Thereafter, the connecting wall portion 106 is sandwiched between the distal end portion 365 of the movable die 364 and the pressing portion of the lower die 370 to compress the connecting wall portion 106 from the mold clamping direction X and from the free end side of the side wall portion 104. As a result, the curved portion of the connecting wall portion 106 disappears, and the thickness of both the side wall portion 104 and the connecting wall portion 106 at the central portion 116 as shown in FIG. 22 due to the material fed into the connecting wall portion 106. Increase. Further, since the pressing portion and the vertical wall portion of the upper mold 360 are continuously and smoothly connected, a part of the material fed into the connecting wall portion 106 is smoothly guided toward the side wall portion side and returned. It is.

  As described above, the pressing portion of the distal end portion 365 of the movable die 364 is flat and does not have a sharp portion, so that the connecting wall portion 106 is punched during and after the mold clamping (the bending process and the thickening process). When pressing to the side, it is excluded that the connecting wall portion 106 is damaged by the movable die 364, and the occurrence of a defect in which a mark or a depression corresponding to the pressing portion of the movable die 364 is formed is suppressed. Further, since the width of the pressing portion of the distal end portion 365 of the movable die 364 is smaller than the width of the base portion of the movable die 364, the material of the connecting wall portion is suppressed from flowing into the moving space of the movable die 364. On the other hand, since the pressure receiving area of the base portion is larger than the pressure releasing area of the distal end portion 365, the function of promoting the formation of bending in the connecting wall portion 106 is ensured. Therefore, the appearance quality of the part (press-molded product) can be improved.

  When the mold clamping is completed, the base portion of the movable die 364 is restrained by the stopper 368, and the cross-sectional thickness between the pressing portion of the distal end portion 365 of the movable die 364 and the pressing portion of the lower die 370 is increased. It is positioned so as to match the plate thickness. Thereby, the pressing part of the movable mold 364 is positioned on the surface of the connecting wall part 106 where the plate thickness is increasing. Therefore, it is possible to suppress the occurrence of a defect in which a mark or a depression corresponding to the pressing portion of the distal end portion 365 of the movable mold 364 is formed, and it is possible to improve the appearance quality of the part (press-molded product).

  As described above, according to the third embodiment, since the pressing portion of the movable tip portion is flat and does not have a sharp portion, it is excluded that the connecting wall portion is damaged by the movable sharp portion. Occurrence of a defect in which a mark or a depression corresponding to the movable pressing portion is formed is suppressed. Further, since the width of the pressing portion of the movable tip is smaller than the width of the movable base, the material of the connecting wall portion is suppressed from flowing into the movable space. On the other hand, since the pressure receiving area of the base is larger than the pressure releasing area of the tip, the function of promoting the formation of bending in the connecting wall is ensured. Therefore, the appearance quality of the part (press-molded product) can be improved.

  In addition, when the mold clamping is completed, the sectional thickness between the pressing portion of the movable mold tip and the pressing portion of the lower mold is positioned so as to coincide with the increased plate thickness. A press part will be located in the surface of the connection wall part which plate | board thickness is increasing. Therefore, it is possible to suppress the occurrence of a defect in which a mark or a depression corresponding to the pressing portion of the movable tip is formed. It should be noted that the first and second modifications according to the first embodiment can be incorporated into the third embodiment.

  Next, a fourth embodiment will be described.

  FIG. 23 is a cross-sectional view for explaining the device for manufacturing a press-formed product according to the fourth embodiment.

  The fourth embodiment relates to the structure of the cavity surface of the movable mold, and is generally different from the second and third embodiments. The apparatus for manufacturing a press-formed product according to the fourth embodiment includes an upper mold (die part) 460, a lower mold ( Punch portion) 470 and side die 480. The upper mold 460 includes a through hole 462, a movable mold 464, and a spring mechanism 466.

  The movable mold 464 is disposed so as to be able to protrude and retract from the through hole 462, and is located outside the blank. The movable mold 464 has a cavity surface with a U-shaped cross section corresponding to the entire outer shape of the central portion of the press-formed product, and the cavity surface includes a curved pressing portion corresponding to the connecting wall portion 126, and a side wall. It has a vertical wall portion corresponding to the portion 124 and extending in the mold clamping direction X. Therefore, the movable mold 464 moves toward the lower mold 470 while restraining the side wall portion 104 and the connecting wall portion 106 of the blank central portion 116 during the mold clamping operation. Reference numeral 472 indicates a step portion of the lower mold 470 that contacts the blank extension portion 114.

  Next, a method for manufacturing a press-formed product according to Embodiment 4 will be described.

  24 and 25 are cross-sectional views for explaining the formation of the bending portion and the disappearance of the bending portion in the method for manufacturing a press-formed product according to Embodiment 4. FIG.

  When the upper mold 460 is lowered toward the lower mold 470 for clamping and press molding, the pressing portion of the movable mold 464 protruding from the through hole 462 of the upper mold 460 is a blank disposed on the lower mold 470. In contact with the connecting wall portion 106 of the blank central portion 116. The urging force of the movable mold 464 is carried out by pressing the expansion part 114 protruding from the free end side of the side wall part 104 toward the step part 472 of the lower mold 470 via the connecting wall part 106 and the side wall part 104. The extension part 114 deform | transforms similarly to the case of FIG. The gap between the pressing portion of the movable mold 464 facing the connecting wall portion 106 and the pressing portion of the lower mold 470 is larger than the clearance between the vertical wall portion of the movable mold 464 facing the side wall portion 104 and the vertical wall portion of the lower mold 470. Therefore, the material of the expanded portion 114 flows upward and is pushed in.

  Since the connecting wall portion 106 is in contact with the pressing portion of the movable mold 464, the force (flowing material) acting on the connecting wall portion 106 from the side wall portion 104 supported by the step portion 472 of the lower mold 470 is connected. As shown in FIG. 24, the central portion of the wall portion 106 is bent toward the lower mold side (a curved portion is formed). That is, in the bending step, the movable wall 464 pushes the connecting wall portion 106 to the lower die side, thereby promoting the formation of the bending in the connecting wall portion 106. For this reason, even if it is a blank of a shape which is hard to bend, for example, since a connection wall part can be bent easily, it is possible to expand an application range.

  Thereafter, the connecting wall 106 is sandwiched between the movable mold 464 and the lower mold 470 so that the connecting wall 106 is compressed from the mold clamping direction X, and is compressed from the free end side of the side wall 104, thereby connecting the connecting wall 106. The curved portion of the portion 106 disappears, and the thickness of both the side wall portion 104 and the connecting wall portion 106 in the blank central portion 116 is increased by the material fed into the connecting wall portion 106 as shown in FIG. Further, since the pressing portion and the vertical wall portion of the movable mold 464 are connected continuously and smoothly, a part of the material fed into the connecting wall portion 106 is smoothly guided toward the side wall portion side and returned. It is.

  As described above, the movable mold 464 has a cavity surface corresponding to the side wall portion 104 and the connecting wall portion 106 of the blank central portion 116 and covers the entire side wall portion 104 and the connecting wall portion 106. Therefore, the material does not flow into the moving space of the movable mold 464 during and after the mold clamping (the bending process and the thickening process), and the side wall section 104 and the connecting wall section 106 are pressed by the pressing portion of the movable mold 464. Is eliminated, and the occurrence of a defect that forms a mark or a depression corresponding to the movable pressing portion is eliminated, so that the appearance quality of the part (press-molded product) can be improved.

  As described above, according to the fourth embodiment, the movable cavity surface covers the entire side wall portion and the connecting wall portion, so that the material does not flow into the movable movement space, and It is excluded that the side wall portion and the connecting wall portion are damaged by the movable pressing portion. Thereby, since the generation | occurrence | production of the malfunction which the trace corresponding to a movable type press part or a hollow part is formed is excluded, the external appearance quality of components (press molded product) can be improved. Note that the first and second modifications according to the first embodiment can be incorporated into the fourth embodiment.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

  For example, the press-formed product is not limited to a form applied to a suspension component, and can be applied to other structural members for a vehicle. Other structural members for vehicles are frame main parts, such as link parts, bracket parts, side sill outer reinforcement, and ladder members, for example.

  By adding a pre-molding function to the press-molded product manufacturing apparatus, the production from the flat plate material (material) that is not preformed to the press-molded product is performed in a series of steps. It is also possible to improve workability and productivity.

  It is also possible to improve the wall-thinning efficiency by providing a suppression means for suppressing the flow of the material causing the increase of the plate thickness to the peripheral portion at the edge of the portion where the plate thickness is increased in the blank. . The suppressing means is not particularly limited as long as it has a structure that inhibits the transmission of compressive stress, and for example, a through hole, a slit, a concave portion, and a bent portion are applicable.

  The size and the number of the through holes are preferably set as appropriate according to the size and shape of the portion where the thickness of the blank is increased. It is preferable in terms of productivity and cost that the slit is formed by punching when a blank is formed from the rolled material. However, the slit can be formed separately by machining. The width and length of the slit are preferably set as appropriate according to the size and shape of the portion where the thickness of the blank is increased. After press molding, if necessary, the slit can be joined by welding or the like to ensure rigidity.

  A recessed part consists of a thin part, and is preferable at a point with little influence with respect to rigidity compared with a slit. It is preferable in terms of productivity and cost that the concave portion is formed by press molding when a blank is formed from a rolled material. However, the recesses can be formed separately by machining, or when casting is applied to the blank, the recesses can be formed collectively at the time of casting. The width and length of the recess are preferably set as appropriate according to the size and shape of the portion where the plate thickness of the blank is increased.

  The bent portion is preferable in that it has less influence on rigidity as compared with the concave portion formed of a thin portion. The cross-sectional shape of the bent portion is not particularly limited, but it is preferable to eliminate (or reduce) the residual marks in the press-formed product by making the shape easy to deform, for example, a gentle arc shape. It is preferable in terms of productivity and cost that the bent portion is formed by press molding when a blank is formed from a rolled material. However, when casting is applied to the blank, it is possible to collectively form a bent portion during casting. The size and length of the bent portion are preferably set as appropriate according to the size and shape of the portion of the blank where the plate thickness is increased.

3 is a perspective view for explaining a press-formed product according to Embodiment 1. FIG. It is sectional drawing regarding line II-II of FIG. It is sectional drawing regarding line III-III of FIG. It is a top view for demonstrating the suspension components to which the press molded product which concerns on Embodiment 1 is applied. It is a perspective view for demonstrating the blank which concerns on Embodiment 1. FIG. FIG. 3 is a cross-sectional view for explaining the device for manufacturing a press-formed product according to Embodiment 1. It is sectional drawing regarding the line VII-VII of FIG. FIG. 6 is a cross-sectional view showing a process of pushing in an extension part in the method for manufacturing a press-formed product according to Embodiment 1. 6 is a cross-sectional view for explaining formation of a curved portion in the method for manufacturing a press-formed product according to Embodiment 1. FIG. FIG. 6 is a cross-sectional view for explaining disappearance of a curved portion in the method for manufacturing a press-formed product according to Embodiment 1. FIG. 10 is a perspective view for explaining a first modification according to the first embodiment. FIG. 6 is a cross-sectional view for explaining a first modification according to the first embodiment. FIG. 10 is a perspective view for explaining a second modification according to the first embodiment. FIG. 10 is a cross-sectional view for explaining a second modification according to the first embodiment. 6 is a cross-sectional view for explaining a device for manufacturing a press-formed product according to Embodiment 2. FIG. FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 15. 10 is a cross-sectional view for explaining the formation of a curved portion in the method for manufacturing a press-formed product according to Embodiment 2. FIG. FIG. 10 is a cross-sectional view for explaining disappearance of a curved portion in the method for manufacturing a press-formed product according to Embodiment 2. FIG. 6 is a cross-sectional view for explaining a device for manufacturing a press-formed product according to Embodiment 3. It is sectional drawing regarding line XX-XX of FIG. 10 is a cross-sectional view for explaining the formation of a curved portion in the method for manufacturing a press-formed product according to Embodiment 3. FIG. FIG. 10 is a cross-sectional view for explaining disappearance of a curved portion in the method for manufacturing a press-formed product according to Embodiment 3. FIG. 10 is a cross-sectional view for explaining a press-formed product manufacturing apparatus according to Embodiment 4; FIG. 10 is a cross-sectional view for explaining the formation of a curved portion in the method for manufacturing a press-formed product according to Embodiment 4. FIG. 9 is a cross-sectional view for explaining disappearance of a curved portion in a method for manufacturing a press-formed product according to Embodiment 4.

Explanation of symbols

100 blank (preform)
104 side wall,
106 connecting wall,
108 end face,
112, 118 end,
114 extensions,
116 central part,
120 press-formed products,
124 side wall,
126 connecting wall,
132,138 ends,
136 central part (part of the direction in which the U-shaped cross section extends),
140 suspension parts,
160 Upper mold (die part),
170 Lower mold (punch part),
172 steps,
180 lateral type,
260 Upper mold (die part),
262 through-hole,
H.264 movable type,
266 spring mechanism,
268 stopper (stopping means),
270 Lower mold (punch part),
272 steps,
280 lateral type,
360 Upper die (die part),
362 through-hole,
364 movable,
365 tip,
366 spring mechanism,
368 stopper (stopping means),
370 Lower mold (punch part),
372 steps,
380 lateral type,
460 Upper mold (die part),
462 through-hole,
464 movable,
466 spring mechanism,
470 Lower mold (punch part),
472 steps,
480 lateral type,
L direction perpendicular to the longitudinal direction,
P circumferential direction,
X clamping direction,
Y Longitudinal direction (direction in which the U-shaped cross section extends).

Claims (14)

A method of manufacturing a U-shaped cross-section component by press molding,
A preparation step of preparing a preform having a U-shaped cross section having a pair of spaced apart side wall portions and an arc-shaped connection wall portion for connecting ends of the side wall portions;
An arrangement step of arranging the preform in a mold;
In the middle of the mold clamping operation of the mold, a bending step of bending the connecting wall portion with respect to a part in the extending direction of the U-shaped cross section by pressing the preform with the mold.
A material flow is generated by compressing and pushing the bent portion with the mold, and the plate thickness of the side wall portion and the connection wall portion in the part is set to the plate thickness before the mold clamping operation. compared to have a thickness increasing step of increasing, and
The preform prepared in the preparation step has a pushing portion that is disposed on the free end side that is located opposite to the connecting wall portion side in the side wall portion of the part,
In the bending step, by pushing the pushing portion toward the connecting wall portion side and flowing the material of the pushing portion, the connecting wall portion is bent,
In the thickness increasing step, by compressing and pushing the bent portion, a material flow is generated in the bent portion, and the side wall portion and the side wall portion by the material fed from the pushed portion to the connecting wall portion. A method of increasing the thickness of the connecting wall portion . The indented portion of the preform is protruded from the free end side, and the circumference of the cross section including the indented portion in the preform is longer than the circumference of the cross section of the other part of the preform. The method according to claim 1 , wherein the method is set. The molding die has a punch portion disposed inside the preform, and a die portion disposed outside the preform,
The die part has a movable mold that can be freely moved in and out from the pressing part of the die part,
In the deflection step, by said movable mold, said connecting wall in said portion by pressing the punch side, to claim 1 or claim 2, characterized in that to facilitate the formation deflection in the connecting wall The method described. The movable pressing portion is curved,
The movable mold is positioned so that the pressing part of the die part including the pressing part of the movable mold forms a smooth cavity surface when the mold clamping in the thickening process is completed. 3. The method according to 3 . The movable mold has a base portion to which a pressing force is transmitted, and a tip portion that imparts the transmitted pressing force to the connecting wall in the part.
The pressing portion of the tip portion is flat, and the width of the tip portion is smaller than the width of the base portion in the extending direction of the U-shaped cross section, and the pressure receiving area to which the pressing force is transmitted in the base portion is , Larger than the pressure release area for applying the pressing force at the tip,
In the deflection step and the thickening step, the flat-shaped pressing portion of the distal end portion of the movable die, according to claim 3, characterized in that for pressing the connecting wall in the portion on the punch side Method. The movable mold has a cavity surface corresponding to the side wall portion and the connecting wall portion in the part,
The method according to claim 3 , wherein in the bending step and the thickness increasing step, the side wall portion and the connection wall portion are constrained by the movable mold. A press-formed product comprising a U-shaped cross-section part manufactured by the method according to claim 1 . The press-formed product according to claim 7 , wherein the hardness of the portion where the plate thickness is increased is greater than the hardness of the peripheral portion. An apparatus for manufacturing a U-shaped cross-section component by press molding,
A preform having a U-shaped cross section having a pair of spaced apart side wall portions and an arc-shaped connecting wall portion connecting the end portions of the side wall portions is disposed and clamped. And
The mold includes a punch portion disposed inside the preform, and a die portion that presses the outer surface of the preform toward the punch portion by relative movement with the punch portion. And
The sectional thickness of the cavity formed by the punch portion and the die portion at the time of clamping is set to be larger than the plate thickness of the preform, with respect to a part in the extending direction of the U-shaped section,
The punch portion and the die portion are
In the middle of the mold clamping operation, by pressing the preform, the connecting wall portion is bent with respect to a part in the extending direction of the U-shaped cross section,
By compressing and pushing the bent portion, a material flow is generated in the bent portion, and the thickness of the side wall portion and the connecting wall portion in the part is set to the plate before the mold clamping operation. Compared with thickness, increase and
The preform has a push-in portion that is disposed on a free end side that is located opposite to a connecting wall portion side in the side wall portion of the part,
In the middle of the mold clamping operation, the punch portion pushes the pushing portion toward the connecting wall portion, thereby causing the material of the pushing portion to flow , thereby reducing the plate thickness of the side wall portion and the connecting wall portion. device, wherein to increase. The die part has a movable mold that can be freely moved in and out from the pressing part of the die part,
The apparatus according to claim 9 , wherein the movable mold promotes the formation of a bend in the connecting wall portion by pressing the connecting wall portion in the part toward the punch portion side. The mold has a stopping means for stopping the movement of the movable mold,
The movable pressing portion is curved,
The restraining means is set to position the movable die so that the pressing portion of the die portion including the pressing portion of the movable die forms a smooth cavity surface when the mold clamping is completed. The apparatus of claim 10 . The movable mold has a base portion to which a pressing force is transmitted, and a tip portion that imparts the transmitted pressing force to the connecting wall in the part.
The pressing portion of the tip portion is flat, and the width of the tip portion is smaller than the width of the base portion in the extending direction of the U-shaped cross section, and the pressure receiving area to which the pressing force is transmitted in the base portion is The device according to claim 11 , wherein the device has a pressure release area that applies the pressing force at the tip. The movable mold has a cavity surface corresponding to the side wall portion and the connecting wall portion in the part,
The apparatus according to claim 11 , wherein the device moves toward the punch portion while restraining the side wall portion and the connecting wall portion during the mold clamping operation. 14. The apparatus of claim 13 , wherein the movable mold has a U-shaped cavity surface corresponding to the entire outer shape of the U-shaped component.

Images