JP2012024837A - Press-forming die equipment and press-forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide press-forming die equipment which prevents the press-forming die from becoming larger, reduces the product cost by minimizing the pad of a blank and can sufficiently withstand compressive stress by material inflow occurring near bent parts during press forming.SOLUTION: In the press-forming die equipment, a radiator core support member is formed from a plate-like blank 20 by making bent parts at midway points of the long blank in the lengthwise direction so as to provide a nearly hat-shaped section. In the process of forming the radiator core support member by means of a punch 12 and a body side die 11, the pad 20a on the outer marginal portion in a place corresponding to the bent part of the plate-like blank 20 is clamped by a blank holder 13 for the prevention of wrinkling, and the blank holder 13 for the prevention of wrinkling folds the pad 20a of the blank 20 in a direction opposite to the press forming direction of the body side die 11 against the punch 12 so as to prevent wrinkling.

Description

  This invention is a press molding for molding a press molded product having a bent portion in the middle in the longitudinal direction of a long member having a substantially hat-shaped cross section, such as a vehicle body member such as a radiator core support member of an automobile or a front pillar. The present invention relates to a metal mold apparatus and a press molding method.

  2. Description of the Related Art A press-molded product such as a radiator core support or a front pillar of an automobile has a plate-like blank material having a bent portion in the middle in the longitudinal direction of a long member having a substantially hat-shaped cross section. Therefore, when forming such a press-formed product from a plate-shaped blank material, the press-formed product by the press-molding die device is so-called drawing because the press-formed product has a bent portion. Therefore, the press molding die apparatus includes a punch and a die, and also uses a wrinkle-pressing blank holder that suppresses the generation of wrinkles that occur in the peripheral portion of the bent portion by drawing, so that the plate-shaped blank material The surplus part formed in the outer peripheral part must be clamped. However, such surplus parts are reduced as much as possible from the viewpoint of cost reduction or trim molding man-hour reduction because they become waste scraps as trimmed parts that are removed by trimming after molding of the press-molded product. It is requested.

  In view of this point, conventionally, for example, a method for manufacturing an outer panel for a front pillar of an automobile described in Patent Document 1 has been proposed. Such a method of manufacturing an outer panel for a front pillar includes a blank portion for an outer panel, and a blank portion for the outer panel is provided with a cut-off portion that is sandwiched and restrained by a die and a blank holder from the same direction as the press direction and removed by trim processing. A blank material that does not have a cut-off portion is prepared in the remaining part excluding a part of the material. Therefore, the surplus portion that becomes waste material during trim molding after press molding is formed by press molding from a combination of drawing molding in a part provided with a cut-off part of the blank material and bending molding in the remaining part. I am trying to make it as small as possible.

JP 2010-36217 A.

A car body member, for example, a long member such as a radiator core support or a front pillar has a structure having a curvature portion in the middle in the longitudinal direction depending on the design of the car. The part has a substantially hat-shaped cross section, and the flange of the bent portion is configured with different curvatures on the outer peripheral side and the inner peripheral side. Accordingly, since the outer peripheral flange is contracted and flange-formed when press-molding, if simple bending is performed, the material flows in and wrinkles are generated by the surplus material.

  Therefore, in this type of press molding die, using the blank material provided over the entire outer peripheral edge with the cut-out part restrained by the die and the blank holder as the surplus part, the entire peripheral area of the blank material You must restrain the surplus part. As a result, the blank holder has a large-scale configuration in which it has a ring shape surrounding the entire circumference of the punch. As a result, the press-molded product molded by such a press-molding die has a large surplus portion that becomes a waste material due to trim molding after molding. In addition, the cost increases due to a decrease in the material yield rate, the number of trim forming steps after forming increases, or the manufacturing cost of the press mold itself increases.

  This invention suppresses the enlargement of the press molding die itself and the trim molding man-hours, and also reduces the product cost by making the blank portion of the blank material as small as possible, and also in the vicinity of the bent portion in the press molding process. An object of the present invention is to provide a press-molding die apparatus and a press-molding method configured to sufficiently withstand the compressive stress caused by the material inflow generated in the press.

  The mold apparatus for press molding according to the present invention is a press-molded product in which a bent portion is formed in the middle in the longitudinal direction of a long member exhibiting a substantially hat-shaped cross section from a plate-shaped blank material. In the state where the outer peripheral edge is sandwiched between the blank holders for wrinkle pressing, when forming with the punch and the body side die, the wrinkle pressing blank holder is provided in the peripheral part of the bent part in the outer peripheral edge of the plate-shaped blank material, It is characterized in that wrinkles are suppressed by bending in a direction opposite to the press molding direction of the die on the main body side with respect to the punch.

  According to the present invention, the wrinkle-pressing blank holder is bent in the direction opposite to the press-forming direction of the body-side die with respect to the punch at the periphery of the bent portion at the outer peripheral edge portion to be the flange-formed flange of the plate-like blank material. On the other hand, so-called bend forming without using a blank holder is realized at a portion other than the periphery of the bent portion.

  As a result, the plate-like blank material can reduce the material cost due to the high material yield rate by forming a small surplus portion that becomes a wrinkle holding portion at the time of molding, and the wrinkle holding blank holder has a bent portion outer peripheral edge portion. It is only necessary to have a structure that only presses down, and it is possible to achieve a reduction in size and cost of a press molding die device, and it is possible to reduce the number of trim molding steps for cutting off surplus portions performed after press molding. .

  In addition, the wrinkle holding blank holder according to the embodiment of the present invention has a reverse bending die portion fixed to the punch so as to extend to the main body side die side so as to face the outer peripheral side wall of the punch. is doing. Such a reverse bending die portion is formed so that the peripheral portion of the bent portion in the outer peripheral edge portion of the blank material is in the press direction between the outer peripheral side wall portion of the main body side die as the main body side die moves in the press molding direction with respect to the punch. Is configured to be bent in the opposite direction.

  With this configuration, the outer peripheral edge portion of the plate-shaped blank is bent in the direction opposite to the pressing direction of the main body-side die, and the outer peripheral portion of the plate-shaped blank is the outer peripheral side wall of the reverse bending die portion and the main body-side die. It is pressed against the clamping force acting in the opposite direction with respect to the press direction. As a result, in the molding process, the material flowing into the bent portion generates a tensile stress due to the pinching force, and the generation of wrinkles in the peripheral portion of the bent portion can be sufficiently suppressed.

  Further, the press molding method according to the present invention provides a press-molded product in which a bent portion is formed in the middle in the longitudinal direction of a long member exhibiting a substantially hat-shaped cross section from a plate-shaped blank material. When molding with punch and body side die with the peripheral part clamped by wrinkle holding blank holder, reverse bending die part of wrinkle holding holder as the body side die moves in the press molding direction with respect to the punch However, the blank material is formed between the punch and the main body side die while bending the peripheral portion of the blank material at the outer peripheral edge portion of the main body side die in the direction opposite to the press direction. It is characterized by doing.

  According to the press molding method according to the present invention configured as described above, in the process in which the reverse bending die portion molds the blank material while the main body side die moves in the press molding direction with respect to the punch, the main body side die The peripheral portion of the bent portion at the outer peripheral edge of the plate-shaped blank material is bent in the direction opposite to the press direction.

  As a result, the outer peripheral edge portion of the plate-shaped blank is bent in the direction opposite to the pressing direction of the main body side die, and the outer peripheral portion of the plate-shaped blank material is the outer peripheral side wall of the reverse bending die portion and the main body side die. It is pressed down by the clamping force in the opposite direction to the press direction. As a result, in the molding process, the material flowing into the bent portion generates a tensile stress due to the clamping force, and the generation of wrinkles in the peripheral portion of the bent portion can be sufficiently suppressed.

  As a result, in the press molding method according to the present invention, the plate-shaped blank material can reduce the material cost due to the high material yield rate by forming a small surplus portion that becomes a wrinkle pressing portion during molding. At the same time, it is sufficient that the wrinkle-pressing blank holder has a configuration that only presses the outer peripheral edge of the bent portion, and it is possible to reduce the size and cost of the press-molding die device. In addition, it is possible to reduce the number of trim forming steps for cutting off the surplus portion performed after press forming.

  According to this invention, the wrinkle-pressing blank holder is drawn while being bent in the direction opposite to the press-forming direction of the body-side die with respect to the punch at the periphery of the bent portion at the outer peripheral edge of the plate-shaped blank. On the other hand, so-called bending molding without using a blank holder is realized in a portion other than the periphery of the bent portion.

  As a result, the plate-like blank material can reduce the material cost due to the high material yield rate by forming a small surplus portion that becomes a wrinkle holding portion during molding. At the same time, it is sufficient that the wrinkle-pressing blank holder only has a configuration for pressing the outer peripheral edge of the bent portion, and it is possible to reduce the size and cost of the press-molding die device. In addition, it is possible to reduce the number of trim forming steps for cutting off the surplus portion performed after press forming.

It is the schematic perspective view which drawn the radiator core support member which is a vehicle body member of the motor vehicle shape | molded using the die apparatus for press molding concerning this invention. It is a schematic longitudinal cross-sectional view in the mold opening state in the die apparatus for press molding concerning this invention. It is explanatory drawing at the time of the state which set the blank material from the mold open state in FIG. It is explanatory drawing which drawn the middle of the shaping | molding of the blank material by dropping a punch with respect to the main body side die | dye from the state shown in FIG. It is explanatory drawing which drawn the time of completion | finish of shaping | molding of a blank material by lowering | hanging a punch further with respect to the main body side die | dye from the state shown in FIG.

  The mold apparatus for press molding in the embodiment according to the present invention is a plate-shaped press-molded product in which a bent portion is formed in the middle in the longitudinal direction of a long member exhibiting a substantially hat-shaped cross section from a plate-shaped blank material. In the state where the outer peripheral edge of the blank material is sandwiched between the blank holders for wrinkle pressing, when forming with the punch and the body side die, the blank holder for wrinkle pressing is the peripheral part of the bent part at the outer peripheral edge of the plate-shaped blank material. , The blank material is formed by the punch and the main body side die while being bent in a direction opposite to the press forming direction of the main body side die with respect to the punch.

  Next, a press molding die apparatus according to an embodiment adopting the present invention will be described with reference to the drawings. First, in FIG. 1, a radiator core support member 1 constituting a body frame of an automobile is configured as a long member having a substantially hat-shaped cross section, and a pair of bent portions 2 are provided in the middle in the longitudinal direction, for example. It is a formed press-formed product. The radiator core support member 1 has a substantially hat-shaped cross section. Therefore, the radiator core support member 1 includes a substantially U-shaped main body 1a and a flange portion 1b projecting outward from both ends of the substantially U-shaped main body 1a. Have.

  Therefore, the radiator core support member 1 configured in this manner is a long shape having a substantially hat-shaped cross section by press-molding a plate-shaped blank material formed in advance in a predetermined shape using a press-molding die device. Formed on the member. At the same time, it is molded so as to have the bent portion 2 in the middle in the longitudinal direction. In this molding process, when the radiator core support member 1 is bent, the outer peripheral edge flange portion 1b of the bent portion 2 is contracted and flange-formed, so that compressive stress is generated by the inflowing material and wrinkles are generated.

  Therefore, a press molding die apparatus as an embodiment according to the present invention is configured as shown in FIG. That is, the press molding die apparatus 10 of FIG. 2 has a main body side die 11 that is an upper die and a punch 12 that is a lower die. The body-side die 11 has a recessed portion 11a having a stepped inner wall at the center thereof, and a movable blank holder 11b is disposed in the recessed portion 11a. Although the movable blank holder 11b is normally urged to the punch side by the spring body 11c, the lower end surface thereof is arranged so as not to protrude outward from the recessed portion 11a.

  The punch 12 has a punch protrusion 12b at the center by forming a step 12a on the outer periphery thereof. Further, a wrinkle-pressing blank holder 13 is disposed at a portion of the punch 12 that forms the peripheral portion of the bent portion 2 so as to face the outer peripheral side wall 12a-1 of the step portion 12a.

  The wrinkle holding blank holder 13 is provided with a reverse bending die portion 13b fixed to a base 13a fixedly mounted on the punch 12 so as to face the outer peripheral side wall 12a-1 of the step portion 12a. The reverse bending die portion 13b extends toward the main body side die 11 so as to face the punch protrusion 12b, and the upper surface of the reverse bending die portion 13b-1 and the upper surface portion 12b-1 of the punch protrusion 12b are horizontal. It arrange | positions so that it may become substantially flush in a direction.

  Next, a process of press-forming the radiator core support member 1 shown in FIG. 1 according to the embodiment of the present invention configured as described above will be described with reference to FIGS. That is, first, as shown in FIG. 3, in the state where the plate-shaped blank material 20 formed in advance so as to have a predetermined outer peripheral shape is set on the upper surface portion 12 b-1 of the punch protrusion 12 b in the punch 12. The side die 11 is lowered. As a result, the blank material 20 is pressed down by the movable blank holder 11b under the urging force of the spring body 11c. As a result, the blank material is sandwiched between the movable blank holder 11b and the upper surface portion 12b-1 of the punch protrusion 12b.

  From such a state, the main body side die 11 is further lowered, and as shown in FIG. 4, the recessed portion 11a is fitted into the punch protrusion 12b, and the radiator core support member 1 has a substantially U-shaped main body portion 1a in cross section. And the flange part 1b is formed gradually. In this process, the surplus portion 20a formed so as to overhang the peripheral portion where the bent portion 2 is formed at the outer peripheral edge of the blank member 20 moves as the main body side die 11 descends (press molding direction). The main body side die 11 enters the gap between the outer peripheral side wall 11d extending in the vertical direction (press molding direction) and the inner peripheral side wall 13b-1 extending in the vertical direction of the reverse bending die 13b. As a result, the surplus portion 20a is bent in the direction opposite to the press direction while being rubbed by the opposing lower end shoulder portion 11d and upper end shoulder portion 13b-1.

  From this state, the main body side die 11 is punched until the lower surface 11e of the main body side die 11 and the stepped portion 12a of the punch 12 abut against the surplus portion 20a while continuing the ironing in the direction opposite to the pressing direction. It is lowered to the 12th side to complete the forming of the blank material 20. Then, the formed blank member 20 is cut from the trim line TL shown in FIG. 5 by using a trim forming machine (not shown) in a trim forming step which is a separate step, and the radiator core support member 1 is completed. Therefore, at this time, the surplus portion 20a is cut as an end material.

  In the embodiment according to the present invention configured as described above, the blank member 20 has the surplus portion 20a as the outer peripheral side wall portion 11d of the main body die 11 and the reverse bending die 13b- at the outer peripheral edge portion 1b around the bent portion. 1 and is sandwiched between the movable blank holder 11b on the main body side 11 and the upper surface portion 12b-1 of the punch protrusion 12b of the punch 12, thereby blanking the temporary surface 11e of the main body side die to be processed. When the material 20 is pressed and molded, a tensile stress is generated and the generation of wrinkles can be suppressed. On the other hand, at the inner peripheral edge portion 1c of the bent portion, the blank material 20b is bent without being constrained by the press work shown in FIGS.

  As a result, the blank material 20 can reduce the material cost due to the high material yield rate by forming a small surplus portion 20a to be a wrinkle pressing portion at the time of molding, and the wrinkle pressing blank holder 13 has a small surplus portion 20a. It is only necessary to have a structure that can be used as a wrinkle holding part, and it is possible to reduce the size and cost of the press molding die device, and to reduce the trim molding man-hours to cut off the surplus part 20a performed after press molding. can do.

  The wrinkle-pressing blank holder 13 includes a reverse bending die portion 13b that is fixed to the punch 12 so as to extend to the main body die 11 side so as to face the outer peripheral side wall 12a-1 of the punch 12. Have. The reverse bending die portion 13b is provided at the outer peripheral edge portion of the blank material 20 between the outer peripheral side wall 12a-1 of the main body side die 11 as the main body side die 11 moves in the press molding direction with respect to the punch 12. The surplus portion 20a is bent in the direction opposite to the pressing direction.

  By this, the surplus part 20a of the blank material 20 is bent in the direction opposite to the pressing direction of the main body side die 11, and the surplus part 20a is the outer bending side wall part of the reverse bending die part 13b and the main body side die 11. It is pressed down by the clamping force in the direction intersecting the press direction with 11d. As a result, the bent portion 2 is molded while generating a tensile stress during the material inflow that occurs in the molding process, and the generation of wrinkles in the peripheral portion of the bent portion 2 can be sufficiently suppressed.

  In the embodiment according to the present invention described above, the trim processing including the surplus portion 20a remaining after the blank material 20 is formed is performed in a separate process using a separate trim forming machine. However, the present invention is not limited to this, and when the radiator core support member 1 is formed by forming the blank material 20 and the spring back does not occur in the bent portion 2, the trim mechanism is used as a press molding die device. 10 may be built in.

  The present invention described above suppresses the enlargement of the press molding die itself and reduces the blank portion as much as possible to reduce the product cost. In addition, in the press molding process, near the bent portion It is constituted so that a tensile stress may be generated in the material flowing into the. Therefore, the present invention is for forming a press-formed product having a bent portion in the middle in the longitudinal direction of a long member having a substantially hat-shaped cross section, such as a vehicle body member such as a radiator core support member of an automobile or a front pillar. It can be said that it is suitable for a press molding die apparatus or the like.

1 Radiator core support member (body member)
2 Bending part 10 Press molding die device 11 Die body 11d Peripheral side wall part 12 Punch 13 Wrinkle holder 13b Reverse bending die part 20 Blank material

Claims (3)

  A press-molded product in which a bent portion is formed in the middle in the longitudinal direction of a long member having a substantially hat-shaped cross section from a plate-shaped blank material, and the outer peripheral edge portion of the plate-shaped blank material is sandwiched between blank holders for wrinkle suppression. A press-molding die device that is molded by a punch and a body-side die in a worn state, wherein the wrinkle-pressing blank holder is located on the periphery of the bent portion at the outer peripheral edge of the blank material. A press-molding die apparatus, characterized in that it is configured to be wrinkled by bending in a direction opposite to the press-molding direction of the main body side die.   The wrinkle holding blank holder has a reverse bending die portion fixed to the punch so as to extend toward the main body side die so as to face the outer peripheral side wall of the punch, and the reverse bending As the main body side die moves in the press molding direction with respect to the punch, the peripheral portion of the bent portion at the outer peripheral edge portion of the blank material is formed between the die portion and the outer peripheral side wall portion of the main body side die. The press-molding die device according to claim 1, wherein the die device is configured to bend in a direction opposite to the pressing direction.   A press-molded product in which a bent portion is formed in the middle in the longitudinal direction of a long member having a substantially hat-shaped cross section from a plate-shaped blank material, and the outer peripheral edge portion of the plate-shaped blank material is sandwiched between blank holders for wrinkle suppression. It is a press molding method of forming with a punch and a body side die in a worn state, and as the body side die is moved in the press molding direction with respect to the punch, the reverse bending die portion of the wrinkle holding holder is While bending the bent peripheral portion in the outer peripheral edge portion of the blank material between the outer peripheral side wall portion of the main body side die in the direction opposite to the pressing direction, the punch and the main body side die A press molding method characterized by molding a blank material.

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