Method for manufacturing vehicle pillar and press forming die

Abstract

To provide a manufacturing method of a pillar for a vehicle capable of improving yield, and a die for press forming.SOLUTION: The method for manufacturing the vehicle pillar 1 includes a blanking step of cutting a material to obtain a material 2 to be formed, a drawing step of forming the material 2 to be formed using an upper die 12 and a lower die 11 to obtain an intermediate product 3, and a trimming step of removing an unnecessary portion of the intermediate product 3. In the drawing step, first, both end portions of the material 2 to be formed in the longitudinal direction are sandwiched between the pressing pad 17,18 and the punch 13. Next, both end portions of the material 2 to be formed in the lateral direction are sandwiched between the blank holder 14,14 and the die 16. Then, in a state where the holding between the pressing pad 17,18 and the punch 13 and the holding between the blank holder 14,14 and the die 16 are maintained, the central portion of the material 2 to be formed is held between the die 16 and the punch 13 to form the material 2 to be formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a vehicle pillar and a press molding die. [Background technology]

[0002] Automobile bodies require high strength, and high-tensile steel plates (high-tensile materials) are used as materials. In recent years, even higher strength has been required, so ultra-high-tensile materials are also used as materials. These high-tensile and ultra-high-tensile materials have excellent deformation strength and fracture strength, but are known to be difficult to process with press forming such as drawing because of their low ductility.

[0003] For example, a center pillar includes an upper pillar portion that is connected to the roof rail when assembled to the vehicle body, a lower pillar portion that is connected to the side sill when assembled to the vehicle body, and a central pillar portion that connects the upper pillar portion and the lower pillar portion and extends in the height direction of the vehicle body. The upper pillar portion and the lower pillar portion are each formed in a substantially T-shape. The central pillar portion that connects the upper pillar portion and the lower pillar portion is formed in a hat shape that includes a central top plate portion, a pair of vertical wall portions connected to the central top plate portion, and flange portions connected to each of the pair of vertical wall portions.

[0004] Patent Document 1 discloses a die used for drawing in the process of press-forming a center pillar. The die is composed of an upper die, a blank holder, and a lower punch. For drawing, the die is attached to a press, the material is set in a predetermined position, and the press is operated. First, the material is clamped between the upper die and the blank holder. Next, with the material clamped between the upper die and the blank holder, the lower punch is thrust into the center of the material to form a center pillar with a hat-shaped basic cross section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2014 / 050973 Summary of the Invention [Problem to be solved by the invention]

[0006] In a conventional process for press-forming a typical center pillar, the entire circumference of the material is clamped using a blank holder during press-forming, which means that much of the clamped portion must be trimmed (cut away) in a later process. In particular, the upper and lower portions of the center pillar constitute the longitudinal ends of the center pillar, so cutting away much of these longitudinal ends can reduce yields.

[0007] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a method for manufacturing a vehicle pillar and a press molding die that can improve yield. [Means for solving the problem]

[0008] A method for manufacturing a vehicle pillar according to one aspect of the present invention is a method for manufacturing a vehicle pillar including an upper pillar portion that is to be coupled to a roof rail when assembled to the vehicle body, a lower pillar portion that is to be coupled to a side sill when assembled to the vehicle body, and a central portion of the pillar that extends in the height direction of the vehicle body by connecting the upper pillar portion and the lower pillar portion. The manufacturing method includes a blanking process in which a material is cut to obtain a formed material, a drawing process in which the formed material is shaped to obtain an intermediate product using an upper mold having a die and a pair of pressure pads and a lower mold having a punch and a pair of blank holders, and a trimming process in which unnecessary portions of the intermediate product are removed. In the drawing process, first, both longitudinal ends of the formed material are clamped between the pressure pad and the punch, respectively, and then both lateral ends of the formed material are clamped between the blank holder and the die, respectively. While maintaining the clamping between the pressure pad and the punch and the clamping between the blank holder and the die, the central portion of the formed material is clamped between the die and the punch to form the formed material.

[0009] A press-forming die according to one aspect of the present invention is a press-forming die for producing a vehicle pillar by press-forming a workpiece to have an upper pillar portion that is to be connected to a roof rail when assembled to the vehicle body, a lower pillar portion that is to be connected to a side sill when assembled to the vehicle body, and a central pillar portion that connects the upper pillar portion and the lower pillar portion and extends in the height direction of the vehicle body. The press-forming die includes an upper die having a die and a pair of press pads, and a lower die having a punch and a pair of blank holders. The upper die and the lower die are configured to clamp both longitudinal ends of the workpiece between the press pads and the punch, respectively, before the central portion of the workpiece is sandwiched between the die and the punch to form the workpiece. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a method for manufacturing a vehicle pillar and a press-molding die that can improve yield. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic perspective view showing a press molding die according to an embodiment of the present invention. [Figure 2] 1 is a schematic perspective view showing an exploded view of a press-molding die according to an embodiment of the present invention. [Figure 3] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 5] 1 is a schematic plan view of a vehicle pillar (intermediate product) manufactured by a vehicle pillar manufacturing method according to the present embodiment. [Figure 6A] 10A and 10B are explanatory views of clamping between a press pad and a punch in a lower die in the manufacturing method for a vehicle pillar according to the embodiment of the present invention. [Figure 6B] 10A and 10B are explanatory views of clamping between a press pad and a punch in a lower die in the manufacturing method for a vehicle pillar according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The vehicle pillar according to the present embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of convenience and may differ from the actual proportions.

[0013] [Vehicle pillar] A vehicle pillar 1 shown in FIG. 5 is also called a center pillar panel, and is a component that constitutes a part of the center pillar of an automobile, and is generally made of high-tensile steel plate or the like.

[0014] Vehicle pillar 1 includes an upper pillar portion 4 that is connected to a roof rail when assembled to the vehicle body, a lower pillar portion 5 that is connected to a side sill when assembled to the vehicle body, and a pillar central portion 6 that connects the upper pillar portion 4 and the lower pillar portion 5 and extends in the height direction of the vehicle body. The upper pillar portion 4 and the lower pillar portion 5 are each formed in a generally T-shape. The pillar central portion 6 that connects the upper pillar portion 4 and the lower pillar portion 5 is formed in a hat shape that includes a central top plate portion 6a, a pair of vertical wall portions 6b, 6b connected to the central top plate portion 6a, and flange portions 6c connected to each of the pair of vertical wall portions 6b, 6b. When vehicle pillar 1 is assembled to the vehicle body, pillar central portion 6 is curved so as to convex outward from the vehicle body, and accordingly, the upper pillar portion 4 and the lower pillar portion 5 are inclined toward the inside of the vehicle body relative to the height direction (vertical direction) of the vehicle body. The excess material portion 7 provided on the outer side of the vehicle pillar 1 (intermediate product 3) is cut and removed in the trimming process.

[0015] [Processing process] The processing steps for the vehicle pillar 1 according to this embodiment are comprised of (i) a blanking process, (ii) a drawing process (drawing), and (iii) a restriking process, a trimming process, a piercing process, etc. The blanking process is a pre-process in which the material is shaped into an appropriate shape, and the drawing process is a process in which the material is processed into the desired shape (the shape during processing). This drawing process may be performed in multiple steps because it may be difficult to perform the drawing process in one step, such as when the height of the vertical wall portion 6b in the final product shape of the vehicle pillar 1 varies significantly in the longitudinal direction. The drawing process is the most distinctive step in the processing steps for the vehicle pillar 1 according to this embodiment, and its details will be described later. The restriking process, trimming process, and piercing process are post-processes in which the shape that could not be formed in the drawing process is corrected, unnecessary portions are removed from the material processed into the desired shape, and holes, etc. are drilled into the material processed into the desired shape.

[0016] [Details of molding die] As shown in FIGS. 1 to 4, a press-molding die 10 according to this embodiment is configured to include a lower die 11 and an upper die 12.

[0017] The lower die 11 is configured to have a punch 13 for forming the overall shape of the vehicle pillar 1 and a pair of blank holders 14, 14 for restraining the material (workpiece 2). The punch 13 is fixed to a punch holder 15, and the pair of blank holders 14, 14 are arranged outward in the short direction of the punch 13. The pair of blank holders 14, 14 are connected to the lower die 11 by a die cushion mechanism (not shown) and slide relative to the punch 13 in the pressing direction (up and down). The pair of blank holders 14, 14 each clamp the workpiece 2 together with the die 16 of the upper die 12. Note that in Figures 3, 4, 6A, and 6B, the solid lines indicate the shape of the workpiece 2 after press forming is completed, and the double-dashed lines in Figures 6A and 6B indicate the shape before press forming.

[0018] The upper mold 12 is configured to have a die 16 that mainly faces the punch 13, and a pair of press pads 17, 18. The die 16 is fixed to a die holder 19, and the pair of press pads 17, 18 are arranged outward in the longitudinal direction of the die 16. The pair of press pads 17, 18 are connected to the upper mold 12 by a spring mechanism 20 or the like, and slide in the pressing direction (up and down) relative to the die 16. Of the pair of press pads 17, 18, one press pad 17 (upper press pad) holds one longitudinal end (upper pillar 4) of the workpiece 2 together with the punch 13. The other press pad 18 (lower press pad) holds the other longitudinal end (lower pillar 5) of the workpiece 2 together with the punch 13.

[0019] Before the upper die 12 descends, the lower surfaces 17a, 18a of the pair of pressure pads 17, 18 are positioned below the lower surface 16a of the die 16 (see FIG. 3). Therefore, during press molding, the pair of pressure pads 17, 18 come into contact with the workpiece 2 before the die 16 does, making it possible to clamp the workpiece 2 between the pair of pressure pads 17, 18 and the punch 13.

[0020] The clamping force (holding force) of the presser pads 17, 18 is set lower than the clamping force (holding force) of the blank holders 14, 14. For example, the clamping force (holding force) of the presser pads 17, 18 is set to about one-tenth of the clamping force (holding force) of the blank holders 14, 14.

[0021] As described above, the pillar center portion 6 of the vehicle pillar 1 is curved so as to be convex outward from the vehicle body, and accordingly, the pillar upper portion 4 and the pillar lower portion 5 are inclined toward the vehicle body. Therefore, at least a portion of the pressing surfaces (lower surfaces 17a, 18a) of the pressing pads 17, 18 are also inclined.

[0022] In this embodiment, the workpiece 2 placed on the lower mold 11 has an inclined surface 2a that slopes downward relative to the horizontal direction in a portion corresponding to the pillar upper portion 4 (see FIG. 6A). The press pad 17 and punch 13 that hold the inclined surface 2a are formed with clamping surfaces 17b and 13b, respectively, that hold the inclined surface 2a. The press pad 17 and punch 13 that hold the inclined surface 2a have opposing surfaces 17c and 13c that are formed at positions horizontally outside the clamping surfaces 17b and 13b, respectively, that are inclined in the opposite direction (upward) from the inclined surface 2a relative to the horizontal direction. These opposing surfaces 17c and 13c are formed at positions outside the material of the press pad 17 and punch 13. Therefore, the opposing surfaces 17c and 13c do not come into contact with the workpiece 2 during press forming (see FIG. 6B).

[0023] Conversely to the above, the workpiece 2 placed on the lower mold 11 may have an inclined surface that is inclined upward relative to the horizontal direction in the portion corresponding to the pillar upper portion 4. The press pad and punch that clamp the inclined surface may each be formed with a clamping surface that clamps the inclined surface. Furthermore, the press pad and punch that clamp the inclined surface may each have an opposing surface that is inclined in the opposite direction (downward) relative to the horizontal direction to the inclined surface at a position horizontally outside the clamping surface. These opposing surfaces are formed at positions outside the material on the press pad and punch. Therefore, these opposing surfaces do not come into contact with the workpiece during press molding.

[0024] FIG. 5 shows an intermediate product 3 of the vehicle pillar 1 after press forming is completed.

[0025] The portion of the vehicle pillar 1 that corresponds to the pillar upper portion 4 is clamped between the pressure pad 17 and the punch 13 during press forming. That is, one longitudinal end of the workpiece 2 that is clamped between the pressure pad 17 and the punch 13 is part of the portion that will be formed as the pillar upper portion 4 of the vehicle pillar 1. In FIG. 5 , the portion that is clamped between the pressure pad 17 and the punch 13 is indicated by dotted hatching.

[0026] The portion of the vehicle pillar 1 that corresponds to the pillar lower section 5 is clamped between the pressure pad 18 and the punch 13 during press forming. That is, the other longitudinal end of the workpiece 2 that is clamped between the pressure pad 18 and the punch 13 is part of the portion that will be formed as the pillar lower section 5 of the vehicle pillar 1. In Fig. 5, the portion that is clamped between the pressure pad 18 and the punch 13 is indicated by dotted hatching.

[0027] The portion of the vehicle pillar 1 corresponding to the pillar center portion 6 is sandwiched between the die 16 and the punch 13 during press molding.

[0028] During press forming, the excess material portion 7, which is near the portion corresponding to the pillar center portion 6 of the vehicle pillar 1 and is outside the product, and a portion of the flange portion 6c adjacent to the excess material portion 7, are clamped between the die 16 and the blank holder 14.

[0029] [Drawing process details] The specific details of the drawing process will be described below.

[0030] (i) The material (molded material 2) is set in the press molding die 10 (see the double-dashed line portion of the molded material 2 in FIG. 6A).

[0031] (ii) The press is started, and the upper die 12 descends from the top dead center. The workpiece 2 is sandwiched and fixed between the pair of pressure pads 17, 18 of the upper die 12 and the punch 13 of the lower die 11 (see the two-dot chain line portion of the workpiece 2 in FIG. 6B ). The portion of the workpiece 2 sandwiched between the pressure pad 17 and the punch 13 is formed in a substantially flat shape and is not curved. The portion of the workpiece 2 sandwiched between the pressure pad 18 and the punch 13 is also formed in a substantially flat shape and is not curved. Furthermore, as described above, when the vehicle pillar 1 is assembled to the vehicle body, the pillar center portion 6 is curved so as to be convex toward the outside of the vehicle body. Therefore, the punch 13 is shaped to be convex upward, and the die 16 is shaped to be concave downward. Therefore, the workpiece 2 sandwiched between the pair of pressure pads 17, 18 and the punch 13 is curved so as to be convex upward. The clamping between the pair of press pads 17, 18 and the punch 13 is maintained until the press forming is completed.

[0032] (iii) As the upper die 12 further descends, the pair of presser pads 17, 18 slide against the die 16 and become integrated with the die 16, and the workpiece 2 is curved so as to be convex upward by the die 16 and the upper part of the punch 13. Almost simultaneously, the longitudinal center portion (excess material portion 7) of the workpiece 2 is clamped between the pair of blank holders 14, 14 and the die 16. This clamping by the pair of blank holders 14, 14 and the die 16 is maintained until the press forming is completed.

[0033] (iv) As the upper die 12 further descends, the punch 13 of the lower die 11 penetrates the die 16 of the upper die 12 at the center of the press-forming die 10, forming the pillar central portion 6 with a hat-shaped cross section. At this time, the lateral ends of the workpiece 2 are clamped and restrained by the blank holders 14, 14, and the pillar central portion 6 is formed into a hat shape. As in a typical drawing process, the lateral ends of the workpiece 2 are clamped by the blank holders 14, 14, which suppresses the occurrence of wrinkles and springback. At the same time, the longitudinal ends of the workpiece 2 are clamped by the pressure pads 17, 18. At this time, a tensile stress acts on the longitudinal ends of the workpiece 2, but because the workpiece 2 is clamped between the pair of pressure pads 17, 18, only an appropriate amount is pulled in. In other words, the same effects can be achieved as when press forming is performed by clamping the entire periphery of the workpiece 2 using blank holders, as in a typical press-forming die.

[0034] Furthermore, since the longitudinal ends of the workpiece 2 do not need to be clamped by the blank holders 14, 14, the longitudinal dimensions of the material (workpiece 2) can be reduced, making it possible to improve yield.

[0035] Generally, center pillars have a curved shape with their central portion protruding outward from the vehicle body, so that the upper pillar portion 4 and the lower pillar portion 5, which are the mounting surfaces for the vehicle body, are inclined toward the interior of the vehicle body. In this case, the press-molding die 10 has a surface that slopes downward as it extends outward in the longitudinal direction (see FIG. 6A). Therefore, when the pressure pad 17 is pressed against the punch 13, the pressure pad 17 is subjected to a lateral load, which may result in poor sliding of the pressure pad 17 or damage.

[0036] Therefore, when either of the presser pads 17, 18 has a surface that slopes more significantly outward in the longitudinal direction (in this embodiment, the presser pad 17 that clamps the pillar upper portion 4), the presser surface of the presser pad 17 and the opposing receiving surface of the punch 13 are made V-shaped. In other words, the presser surface of the presser pad 17 and the opposing receiving surface of the punch 13 are provided with an inclined surface (opposing surfaces 17c, 13c) that faces in the opposite direction to the inclined surface required for forming. It is preferable that this inclined surface (opposing surfaces 17c, 13c) be set outside the material (at a position where the material is not clamped).

[0037] When the material is clamped between the press pads 17, 18 and the punch 13, the material may be deformed into a V-shape and clamped.

[0038] [Actions and effects] The effects of this embodiment will be described below.

[0039] (1) The manufacturing method for a vehicle pillar 1 according to this embodiment is a method for manufacturing a vehicle pillar 1 including an upper pillar portion 4 that is connected to a roof rail when assembled to the vehicle body, a lower pillar portion 5 that is connected to a side sill when assembled to the vehicle body, and a pillar central portion 6 that extends in the height direction of the vehicle body by connecting the upper pillar portion 4 and the lower pillar portion 5. The manufacturing method includes a blanking process for cutting a material to obtain a workpiece 2, a drawing process for forming the workpiece 2 to obtain an intermediate product 3 using an upper mold 12 having a die 16 and a pair of pressure pads 17, 18, and a lower mold 11 having a punch 13 and a pair of blank holders 14, 14, and a trimming process for removing unnecessary portions of the intermediate product 3. In the drawing process, first, both longitudinal ends of the workpiece 2 are clamped between the pressure pads 17, 18 and the punch 13, respectively, and then both lateral ends of the workpiece 2 are clamped between the blank holders 14, 14 and the die 16, respectively.While maintaining the clamping between the pressure pads 17, 18 and the punch 13, and the clamping between the blank holders 14, 14 and the die 16, the central portion of the workpiece 2 is clamped between the die 16 and the punch 13 to form the workpiece 2.

[0040] In this embodiment, during press forming, first, both longitudinal end portions of the workpiece 2 are clamped between the press pads 17, 18 and the punch 13. By doing so, there are no portions at the longitudinal end portions of the workpiece 2 that are clamped by the blank holders 14, 14, so the longitudinal dimension of the material (workpiece 2) can be reduced, and the yield can be improved.

[0041] As described above, according to this embodiment, it is possible to provide a method for manufacturing the vehicle pillar 1 that can improve the yield.

[0042] (2) One longitudinal end of the workpiece 2 sandwiched between the pressure pad 17 and the punch 13 is part of the portion to be molded as the pillar upper part 4 of the vehicle pillar 1. The other longitudinal end of the workpiece 2 sandwiched between the pressure pad 18 and the punch 13 is part of the portion to be molded as the pillar lower part 5 of the vehicle pillar 1.

[0043] In this embodiment, the portion of the workpiece 2 that is clamped between the pressure pads 17, 18 and the punch 13 is not a portion that will become part of the product, so there is no need to provide excess material at both longitudinal ends of the workpiece 2, making it possible to improve yield.

[0044] (3) At least one of the longitudinal ends of the workpiece 2 placed on the lower die 11 has an inclined surface 2a that is inclined downward or upward with respect to the horizontal direction. The presser pad 17 and punch 13 that hold the inclined surface 2a are formed with clamping surfaces 17b and 13b that hold the inclined surface 2a, respectively. The presser pad 17 and punch 13 that hold the inclined surface 2a are formed with opposing surfaces 17c and 13c that are inclined in the opposite direction to the inclined surface 2a with respect to the horizontal direction, at positions horizontally outward of the clamping surfaces 17b and 13b.

[0045] Generally, a center pillar has a curved shape with its center portion protruding outward from the vehicle body, so that the upper pillar portion 4 and the lower pillar portion 5, which are the mounting surfaces for the vehicle body, are inclined toward the inside of the vehicle body. In this case, the press-molding die 10 has a surface that slopes downward as it extends outward in the longitudinal direction (see FIG. 6A). Therefore, when the pressure pad 17 is pressed against the punch 13, the pressure pad 17 is subjected to a lateral load, which may result in poor sliding of the pressure pad 17 or damage.

[0046] Therefore, in this embodiment, the upper presser pad (presser pad 17) that clamps the inclined surface 2a and the punch 13 are provided with clamping surfaces 17b, 13b and opposing surfaces 17c, 13c, and the presser surface of the presser pad 17 and the opposing receiving surface of the punch 13 are made V-shaped to generate a load that opposes the lateral load of the presser pad 17, thereby maintaining balance.

[0047] (4) The press-forming die 10 according to this embodiment is a press-forming die 10 for producing a vehicle pillar 1 by press-forming a workpiece 2, the vehicle pillar 1 including: an upper pillar portion 4 that is connected to a roof rail when assembled to the vehicle body; a lower pillar portion 5 that is connected to a side sill when assembled to the vehicle body; and a pillar central portion 6 that connects the upper pillar portion 4 and the lower pillar portion 5 and extends in the height direction of the vehicle body. The press-forming die 10 includes an upper die 12 having a die 16 and a pair of press pads 17, 18; and a lower die 11 having a punch 13 and a pair of blank holders 14, 14. The upper die 12 and the lower die 11 are configured to clamp both longitudinal ends of the workpiece 2 between the press pads 17, 18 and the punch 13, respectively, before the central portion of the workpiece 2 is sandwiched between the die 16 and the punch 13 to form the workpiece 2.

[0048] In this embodiment, during press forming, first, both longitudinal end portions of the workpiece 2 are clamped between the press pads 17, 18 and the punch 13. By doing so, there are no portions at the longitudinal end portions of the workpiece 2 that are clamped by the blank holders 14, 14, so the longitudinal dimension of the material (workpiece 2) can be reduced, and the yield can be improved.

[0049] As described above, according to this embodiment, it is possible to provide a press-molding die 10 that can improve yield.

[0050] (5) One longitudinal end of the workpiece 2 sandwiched between the pressure pad 17 and the punch 13 is part of the portion to be molded as the pillar upper part 4 of the vehicle pillar 1. The other longitudinal end of the workpiece 2 sandwiched between the pressure pad 18 and the punch 13 is part of the portion to be molded as the pillar lower part 5 of the vehicle pillar 1.

[0051] In this embodiment, the portion of the workpiece 2 that is clamped between the pressure pads 17, 18 and the punch 13 is not a portion that will become part of the product, so there is no need to provide excess material at both longitudinal ends of the workpiece 2, making it possible to improve yield.

[0052] (6) At least one of the longitudinal ends of the workpiece 2 placed on the lower die 11 has an inclined surface 2a that is inclined downward or upward with respect to the horizontal. The presser pad 17 and punch 13 that hold the inclined surface 2a are formed with clamping surfaces 17b and 13b that hold the inclined surface 2a, respectively. The presser pad 17 and punch 13 that hold the inclined surface 2a are formed with opposing surfaces 17c and 13c that are inclined in the opposite direction to the inclined surface 2a with respect to the horizontal at positions horizontally outward of the clamping surfaces 17b and 13b, respectively.

[0053] Generally, a center pillar has a curved shape with its center portion protruding outward from the vehicle body, so that the upper pillar portion 4 and the lower pillar portion 5, which are the mounting surfaces for the vehicle body, are inclined toward the inside of the vehicle body. In this case, the press-molding die 10 has a surface that slopes downward as it extends outward in the longitudinal direction (see FIG. 6A). Therefore, when the pressure pad 17 is pressed against the punch 13, the pressure pad 17 is subjected to a lateral load, which may result in poor sliding of the pressure pad 17 or damage.

[0054] Therefore, in this embodiment, the upper presser pad (presser pad 17) that clamps the inclined surface 2a and the punch 13 are provided with clamping surfaces 17b, 13b and opposing surfaces 17c, 13c, and the presser surface of the presser pad 17 and the opposing receiving surface of the punch 13 are made V-shaped to generate a load that opposes the lateral load of the presser pad 17, thereby maintaining balance.

[0055] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0056] 1 Vehicle pillar (front pillar panel) 2 Material to be molded 2a Slope 3 Intermediate products 4 Upper part of pillar 5 Lower pillar 6 Center of pillar 10 Press molding dies 11 Lower mold 12 Upper mold 13 Punch 13b Clamping surface 13c Opposite surface 14 Blank holder 16 Die 17 Presser pad (upper presser pad) 17b Clamping surface 17c Opposite side 18 Presser pad (lower presser pad)

Claims

1. A method for manufacturing a vehicle pillar including: an upper pillar portion that is coupled to a roof rail when assembled to a vehicle body; a lower pillar portion that is coupled to a side sill when assembled to the vehicle body; and a pillar center portion that connects the upper pillar portion and the lower pillar portion to form a pillar center portion that extends in a height direction of the vehicle body, a blanking step of cutting the material to obtain a workpiece; a drawing step in which the workpiece is formed using an upper mold having a die and a pair of pressing pads and a lower mold having a punch and a pair of blank holders to obtain an intermediate product; a trimming step of removing unnecessary portions of the intermediate product, In the drawing step, First, both longitudinal ends of the workpiece are clamped between the press pad and the punch, Next, both ends of the workpiece in the short direction are clamped between the blank holder and the die, while maintaining the clamping between the press pad and the punch and the clamping between the blank holder and the die, the central portion of the workpiece is sandwiched between the die and the punch to form the workpiece. A method for manufacturing a vehicle pillar.

2. one end in the longitudinal direction of the workpiece that is clamped between the press pad and the punch is a part of a portion that will be molded as the pillar upper portion of the vehicle pillar, the other end of the workpiece in the longitudinal direction that is clamped between the press pad and the punch is a part of a portion that will be molded as the pillar lower portion of the vehicle pillar. A method for manufacturing the vehicle pillar according to claim 1.

3. At least one of the longitudinal end portions of the workpiece arranged on the lower die has an inclined surface inclined downward or upward with respect to the horizontal direction, the presser pad and the punch, which sandwich the inclined surface, each have a clamping surface which sandwiches the inclined surface; the pressing pad and the punch that sandwich the inclined surface have opposing surfaces formed at positions on the horizontal outer side of the sandwiching surfaces, the opposing surfaces being inclined in a direction opposite to the horizontal direction of the inclined surface; The method for manufacturing a vehicle pillar according to claim 1 or 2.

4. A press-molding die for manufacturing a vehicle pillar by press-molding a workpiece, the vehicle pillar including: an upper pillar portion to be connected to a roof rail when assembled to a vehicle body; a lower pillar portion to be connected to a side sill when assembled to the vehicle body; and a pillar center portion connecting the upper pillar portion and the lower pillar portion and extending in a height direction of the vehicle body, an upper mold having a die and a pair of pressing pads; a punch and a lower die having a pair of blank holders, the upper mold and the lower mold are configured to clamp both longitudinal ends of the workpiece between the press pad and the punch, respectively, before the workpiece is molded by sandwiching a central portion thereof between the die and the punch. Press molding die.

5. one end in the longitudinal direction of the workpiece that is clamped between the press pad and the punch is a part of a portion that will be molded as the pillar upper portion of the vehicle pillar, the other end of the workpiece in the longitudinal direction that is clamped between the press pad and the punch is a part of a portion that will be molded as the pillar lower portion of the vehicle pillar. The press molding die according to claim 4.

6. At least one of the longitudinal end portions of the workpiece arranged on the lower die has an inclined surface inclined downward or upward with respect to the horizontal direction, the presser pad and the punch, which sandwich the inclined surface, each have a clamping surface which sandwiches the inclined surface; the pressing pad and the punch that sandwich the inclined surface have opposing surfaces formed at positions on the horizontal outer side of the sandwiching surfaces, the opposing surfaces being inclined in a direction opposite to the horizontal direction of the inclined surface; The press molding die according to claim 4 or 5.

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