Press die for hat-shaped cross-sectional parts

Abstract

To provide a press die for a hat-shaped cross section component that can reduce spring back and so on occurring at a vertical wall part, and can improve productivity while avoiding deformation of the vertical wall part after bending formation without use of a die cushion device with locking function.SOLUTION: A press die 10 comprises a punch mold 1 having a fixed punch 11 and a movable punch 12, and a die mold 2 having a bending blade 21 and a pad 22. The punch mold and the die mold are proximate to each other to bend a steel plate into a hat cross section shape, and the press die adds tensile force to a vertical wall part when the movable punch moves from a proximate position to a separation position. The press die comprises a distance control mechanism 3 which controls a relative distance between the movable punch and the pad, brings a first block member 31 into contact with a second block member 32 until the movable punch moves to the separation position, and fixes the relative distance to a prescribed distance at the separation position, and when the pad is separated from a top position M1 after completion of bending formation, separates the first block member and the second block member from each other in a vertical direction.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a press die for hat-shaped cross-sectional parts, and more particularly, to a press die for hat-shaped cross-sectional parts for press-forming a steel plate into a hat-shaped cross-sectional shape.

Background Art

[0002] In recent years, as one of the measures to achieve both weight reduction and high strength of press parts constituting an automobile body, the high hardening of steel sheets has been promoted. However, for example, in a vehicle member part having a hat-shaped cross-sectional shape, springback, warpage, etc. are likely to occur in the vertical wall portion constituting the hat-shaped cross-section, and the springback, warpage, etc. in this vertical wall portion are due to the residual stress generated in the vertical wall portion accompanying the press forming (drawing forming or bending forming) of the steel sheet being different between the inner side and the outer side of the plate. It is known that as the high hardening of the steel sheet progresses, it occurs more prominently.

[0003] A press die that efficiently removes the difference in residual stress between the inner and outer sides of the plate, which causes factors such as springback and warping in this vertical wall portion, is disclosed, for example, in Patent Document 1. That is, as shown in FIG. 27, Patent Document 1 discloses a lower die 100 having a lower die punch 101 and a lower die cushion 104, and an upper die 200 having an upper die bending blade 201 and an upper die pad 202. A press die 300 for a vehicle member part that press-forms a vehicle member part M having a top portion M1 and a vertical wall portion M2 by bending a steel plate W, wherein the lower die cushion 104 is provided with a convex forming portion 102a that protrudes outward from the vertical wall forming portion 102 of the lower die punch 101 to the outer side of the plate at the inner peripheral edge of the flange pressing portion 103, and the upper die bending blade 201 is provided with a concave forming portion 201a that cooperates with the convex forming portion 102a above the die R portion 201R. As shown in FIG. 27(b), when the upper die 200 descends until just before the bottom dead center, the convex forming portion 102a and the concave forming portion 201a bend the tip flange portion W1 of the steel plate W stepwise to form a step-shaped portion M3 on the tip side of the vertical wall portion M2. As shown in FIG. 27(c), a press die 300 for a vehicle member part is disclosed, which is formed such that when the upper die 200 descends a minute distance d1 to the bottom dead center while the convex forming portion 102a and the concave forming portion 201a grip the step-shaped portion M3.

[0004] And in the press die 300 for the vehicle member part, when the upper die 200 descends a minute distance d1 to the bottom dead center while the convex forming portion 102a and the concave forming portion 201a grip the step-shaped portion M3, the longitudinal tension F applied to the vertical wall portion M2 removes the difference between the residual stresses remaining on the inner and outer sides of the plate of the vertical wall portion M2 in the vehicle member part M, and the vertical wall portion M2 can be shape-frozen into a regular cross-sectional shape. As a result, problems such as springback and warping occurring in the vertical wall portion M2 of the vehicle member part M can be solved.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the press die 300 for vehicle member parts described in Patent Document 1, after bending forming, with the upper die pad 202 pressing the steel plate W against the lower die punch 101, the lower die cushion 104 is pushed by the pressure pin 106 and moves toward the lower die punch 101 side. To prevent deformation of the vertical wall portion M2 after press forming, a pressure device equipped with a locking mechanism for temporarily stopping the ascent of the pressure pin 106 at the bottom dead center is required. Therefore, there was a problem that the press machine that can use the press die 300 for vehicle member parts was limited to some press machines having a pressure device (die cushion device) equipped with a locking mechanism. And, press machines having a die cushion device with a locking mechanism generally had a small number of units, and the setup of the press die was limited and inconvenient.

[0007] Also, in the die cushion device with a locking mechanism, there was a problem that the cycle time of press forming became long and its productivity decreased because the movement of the lower die cushion 104 toward the lower die punch 101 side was temporarily stopped at the bottom dead center.

[0008] Furthermore, the movable stroke amount (movement amount) d1 of the lower die cushion 104 is a minute distance d1 (about 2 to 5 mm) that can remove the difference in residual stress in the vertical wall portion M2. However, in the die cushion device of a press machine, since an air cylinder is usually used for pressurization, there was a problem that it was difficult to stably generate the required pressing force with a minute movable stroke amount.

[0009] The present invention has been made to solve the above problems, and while reducing springback, warping, etc. that occur in the vertical wall portion accompanying the press forming of hat-shaped cross-sectional parts, it is an object of the present invention to provide a press die for hat-shaped cross-sectional parts that can improve productivity while avoiding deformation of the vertical wall portion after completion of press forming without using a die cushion device with a locking mechanism of a press machine.

Means for Solving the Problem

[0010] In order to achieve the above object, the press die for hat-shaped cross-sectional parts according to the present invention has the following configuration. (1) A fixed punch fixed to a die base and having a zenith forming portion and a vertical wall forming portion formed in a U-shaped cross-sectional shape, and a convex forming portion and a flange forming portion that project stepwise outward from the plate at the tip side of the vertical wall forming portion, and a movable punch formed to be vertically movable between a proximity position close to the fixed punch and a separation position separated from the fixed punch, and a punch die having a pressing unit supported by the die base for pressing the movable punch toward the fixed punch side, A bending blade having a concave forming portion formed to face the convex forming portion, and a die having a pad disposed on the inner peripheral side of the bending blade and formed to be able to press a steel plate against the zenith forming portion, In a state where the movable punch has moved to the proximity position, the punch die and the die die are bent and formed into a hat cross-sectional shape including a zenith portion and vertical wall portions standing on both sides thereof in proximity to each other, and the bending blade and the movable punch bend and form the tip portion of the vertical wall portion into a stepped shape portion, A press die for hat-shaped cross-sectional parts, wherein when the movable punch is pushed by the bending blade and moves from the proximity position to the separation position while the bending blade and the movable punch hold the stepped shape portion, a longitudinal tension is applied to the vertical wall portion to complete the bending forming, The punch die is provided with a distance control mechanism having a first block member and a second block member for controlling the vertical relative distance between the movable punch and the pad, The distance control mechanism is When the first block member and the second block member are separated in the vertical direction, the relative distance is not regulated, Before the movable punch is pushed by the bending blade and moves from the proximity position to the separation position, the first block member and the second block member are brought into contact with each other in the vertical direction to fix the relative distance at a predetermined distance at the separation position. After the bending forming is completed, until the movable punch is pushed by the pressurizing unit and moves from the separation position to the proximity position, the first block member and the second block member are maintained in a state of being in contact with each other in the vertical direction. When the pad separates from the zenith portion, the first block member and the second block member are separated from each other in the vertical direction.

[0011] In the present invention, the punch type is provided with a distance control mechanism having a first block member and a second block member for controlling the relative distance in the vertical direction between the movable punch and the pad. The distance control mechanism does not regulate the relative distance when the first block member and the second block member are separated from each other in the vertical direction. Before the movable punch is pushed by the bending blade and moves from the proximity position to the separation position, the first block member and the second block member are brought into contact with each other in the vertical direction to fix the relative distance at a predetermined distance at the separation position. After the bending forming is completed, until the movable punch is pushed by the pressurizing unit and moves from the separation position to the proximity position, the first block member and the second block member are maintained in a state of being in contact with each other in the vertical direction. When the pad separates from the zenith portion, the first block member and the second block member are separated from each other in the vertical direction. Therefore, after the punch type and the die type are brought close to each other to bend the steel plate into a hat-shaped cross-sectional part and add longitudinal tension to the vertical wall portion to complete the bending forming, when the movable punch is moved toward the fixed punch side by the pressing force of the pressurizing unit, deformation of the vertical wall portion of the hat-shaped cross-sectional part due to the pressing force of the pressurizing unit or the pressing force of the pad can be avoided.

[0012] That is, the punch type is provided with a distance control mechanism having a first block member and a second block member that control the vertical relative distance between the movable punch and the pad. When the first block member and the second block member are separated in the vertical direction, the distance control mechanism does not regulate the relative distance. After the bending forming is completed, when the pad separates from the zenith portion, the first block member and the second block member are separated in the vertical direction. Therefore, the next bending forming can be started in a state where the first block member and the second block member are separated in the vertical direction and the vertical relative distance between the movable punch and the pad is not regulated. Therefore, at the start of the bending forming, with the pad pressing the steel plate against the zenith forming portion in a state where the movable punch has moved to the proximity position by the pressing force of the pressing unit, the punch die and the die approach each other, and the steel plate is bent into a hat cross-sectional shape including a zenith portion and vertical wall portions standing on both sides thereof. The bending blade and the movable punch can form a stepped portion at the tip of the vertical wall portion.

[0013] Also, the distance control mechanism abuts the first block member and the second block member in the vertical direction and fixes the relative distance to a predetermined distance before the movable punch is pushed by the bending blade and moves from the proximity position to the separation position. Therefore, during the movement of the movable punch from the proximity position to the separation position when pushed by the bending blade, the vertical relative distance between the movable punch and the pad is not regulated. Therefore, with the pad pressing the zenith portion against the zenith forming portion of the fixed punch, the bending blade and the movable punch grip the stepped portion and apply a longitudinal tension to the vertical wall portion, removing the difference between the inner and outer sides of the plate of the residual stress in the vertical wall portion, and the bending forming can be completed. Also, the distance control mechanism fixes the relative distance to a predetermined distance at the separation position of the movable punch with respect to the fixed punch. Therefore, at the die closing position of the punch die and the die where the bending forming is completed, the state of applying a longitudinal tension to the vertical wall portion can be maintained, and the shape can be frozen into a regular cross-sectional shape. Therefore, springback, warping, etc. generated in the vertical wall portion of the hat-shaped cross-section component can be reduced.

[0014] In addition, after the bending forming is completed, the distance control mechanism maintains the state where the first block member and the second block member are in contact with each other in the vertical direction until they are pushed by the pressing unit and move from the separated position to the proximity position. Therefore, the pad and the movable punch that sandwich the hat-shaped cross-sectional part after the bending forming are simultaneously moved from the separated position to the proximity position of the movable punch relative to the fixed punch while maintaining the relative distance in the vertical direction at a predetermined distance. Also, when the pad separates from the zenith, the distance control mechanism separates the first block member and the second block member in the vertical direction. Thus, even after the movable punch stops at the proximity position, the pad is restricted until it separates from the zenith, and deformation of the vertical wall portion of the hat-shaped cross-sectional part due to the pressing force of the pad can be avoided. Therefore, deformation of the vertical wall portion of the hat-shaped cross-sectional part due to the pressing force of the pressing unit or the pressing force of the pad can be avoided.

[0015] In addition, when the distance control mechanism moves the movable punch to the proximity position of the fixed punch by the pressing force of the pressing unit after the bending forming is completed, the pad and the movable punch are simultaneously moved while maintaining the relative distance in the vertical direction at a predetermined distance. Therefore, it is not necessary to use a pressing device equipped with a locking mechanism for temporarily stopping the movable punch at the separated position for the pressing unit. As a result, the press machine that can use the press die for this hat-shaped cross-sectional part is not limited to some press machines equipped with a locking mechanism. As a result, the setup of the press die for this hat-shaped cross-sectional part is not limited to some press machines, and the degree of freedom and convenience of the setup can be improved. Furthermore, after the bending forming is completed, it is not necessary to delay the moving timing for moving the movable punch to the proximity position of the fixed punch, the cycle time in the press forming of the hat-shaped cross-sectional part can be shortened, and its productivity can also be improved.

[0016] Therefore, according to the press die for the hat-shaped cross-sectional part, it is possible to reduce springback, warping, etc. occurring in the vertical wall portion of the hat-shaped cross-sectional part, and without using a die cushion device with a locking mechanism of a press machine, it is possible to provide a press die for a hat-shaped cross-sectional part that can improve productivity while avoiding deformation of the vertical wall portion after bending forming is completed.

[0017] (2) In the press die for the hat-shaped cross-sectional part described in (1), The first block member is supported by the fixed punch so as to be movable in the vertical direction by being pushed by the pad, The second block member is supported by the movable punch so as to be rotatable between a lying position and an upright position, is vertically separated from the first block member at the lying position, and is vertically in contact with the first block member at the upright position.

[0018] In the present invention, the first block member is supported by the fixed punch so as to be movable in the vertical direction by being pushed by the pad, and the second block member is supported by the movable punch so as to be rotatable between a lying position and an upright position, and is vertically separated from the first block member at the lying position. Therefore, when the second block member is rotated to the lying position, the pad can press the steel plate against the zenith forming portion of the fixed punch without being obstructed by the first block member during bending forming. Therefore, the pad can secure the necessary pressing force on the steel plate during bending forming and avoid warping, etc. at the zenith portion of the hat-shaped cross-sectional part.

[0019] Further, since the second block member is vertically in contact with the first block member at the upright position, by simply rotating the second block member from the lying position to the upright position, the vertical relative distance between the movable punch and the pad can be easily fixed to a predetermined distance.

[0020] Therefore, before starting the bending forming, by rotating the second block member to the lying position, the necessary pressing force of the pad against the steel plate during the bending forming can be ensured, and warping of the top part of the hat-shaped cross-sectional part can be easily avoided. At the same time as the completion of the bending forming, by rotating the second block member from the lying position to the standing position, it is possible to easily avoid deformation of the vertical wall portion of the hat-shaped cross-sectional part after the completion of the bending forming due to the pressing force of the pressing unit or the pressing force of the pad.

[0021] (3) In the press die for the hat-shaped cross-sectional part described in (2), The fixed punch is characterized by comprising a first cam portion that rotates the second block member from the lying position to the standing position when the movable punch is pushed by the bending blade and moves from the proximity position to the separation position.

[0022] In the present invention, since the fixed punch is provided with a first cam portion that rotates the second block member from the lying position to the standing position when the movable punch is pushed by the bending blade and moves from the proximity position to the separation position, in conjunction with the movement of the movable punch being pushed by the bending blade and moving from the proximity position to the separation position, the first cam portion can surely rotate the second block member from the lying position to the standing position.

[0023] Therefore, the first block member pushed by the pad and moving toward the movable punch side can come into contact with the second block member rotated to the standing position in the vertical direction, and the relative distance in the vertical direction between the movable punch that has moved to the separation position and the pad can be surely fixed to a predetermined distance. As a result, after the completion of the bending forming, when the movable punch is pushed by the pressing unit and moves from the separation position to the proximity position, deformation of the vertical wall portion of the hat-shaped cross-sectional part sandwiched between the pad and the movable punch due to the pressing force of the pressing unit or the pressing force of the pad can be stably avoided.

[0024] (4) In the press die for the hat-shaped cross-sectional part described in (2) or (3), The fixed punch is provided with a biasing member that biases the first block member toward the pad side. The vertical stroke length of the first block member is formed to be longer than the amount of movement of the movable punch moving between the proximity position and the separation position. The first block member is provided with a second cam portion that rotates the second block member from the upright position to the fallen position when the movable punch is pushed by the biasing member and further moves toward the pad side after moving from the separation position to the proximity position. The second block member is characterized by being provided with a passive cam portion that engages with the second cam portion.

[0025] In the present invention, the fixed punch is provided with a biasing member that biases the first block member toward the pad side. The vertical stroke length of the first block member is formed to be longer than the amount of movement of the movable punch moving between the proximity position and the separation position. The first block member is provided with a second cam portion that rotates the second block member from the upright position to the fallen position when the movable punch is pushed by the biasing member and further moves toward the pad side after moving from the separation position to the proximity position. The second block member is provided with a passive cam portion that engages with the second cam portion. Therefore, after the movable punch stops at the proximity position, when the pad moves to the mold opening position, the first block member can further move by the difference between the stroke length of the first block member and the movement amount of the movable punch due to the biasing force of the biasing member. Then, when the first block member further moves toward the pad side by the biasing force of the biasing member, the second cam portion of the first block member pushes the passive cam portion of the second block member, and the second block member can be automatically rotated from the upright position to the fallen position.

[0026] Therefore, when bending and forming next, the second block member rotated to the lying position is separated from the first block member in the vertical direction, and does not regulate the vertical relative distance between the pad and the movable punch. Thus, with the pad pressing the steel plate against the fixed punch in a state where the movable punch has moved to the proximity position by the pressing force of the pressing unit, the punch die and the die approach each other to bend and form the steel plate into a hat cross-sectional shape having a vertical wall portion that stands up at the zenith portion and both sides thereof, and the bending blade and the movable punch can form a stepped shape portion at the tip of the vertical wall portion. As a result, using the press die for this hat-shaped cross-sectional component, continuous press forming can be performed, the cycle time in the press forming of the hat-shaped cross-sectional component can be shortened, and its productivity can be further improved.

[0027] (5) In the press die for the hat-shaped cross-sectional component described in (4), a support member for rotatably supporting the second block member is fixed to the movable punch, and the support member and the second block member are connected by a turnover spring; the turnover spring is arranged such that, simultaneously with the second cam portion separating from the passive cam portion, a biasing force for rotating the second block member to the lying position acts, and simultaneously with the second cam portion coming into contact with the passive cam portion, a biasing force for rotating the second block member to the standing position acts.

[0028] In the present invention, a support member for rotatably supporting the second block member is fixed to the movable punch, the support member and the second block member are connected by a turnover spring, and the turnover spring is arranged such that, simultaneously with the second cam portion separating from the passive cam portion, a biasing force for rotating the second block member to the lying position acts. Therefore, when the first block member further moves by the difference between the stroke length and the movement amount due to the biasing force of the biasing member, the second cam portion pushes the passive cam portion in the separating direction, and at the same time, the biasing force of the turnover spring acts, so that the second block member can be more reliably rotated to the lying position.

[0029] In addition, since the turnover spring is arranged such that the urging force for rotating the second block member to the upright position acts simultaneously when the second cam portion abuts against the passive cam portion, when the movable punch moves from the proximity position to the separation position and the first cam portion rotates the second block member from the lying position to the upright position, the second cam portion abuts against the passive cam portion and at the same time, the urging force of the turnover spring acts, whereby the second block member can be rotated to the upright position more reliably.

[0030] Therefore, when the movable punch is pushed by the pressing unit and moves to the proximity position to start bending forming, the first block member and the second block member can be more reliably separated in the vertical direction. Further, after the bending forming is completed, when the movable punch is pushed by the pressing force of the pressing unit and moves from the separation position to the proximity position until the pad separates from the zenith portion, the first block member and the second block member can be more reliably brought into contact with each other in the vertical direction, and the relative distance in the vertical direction between the movable punch and the pad can be maintained in a state of a predetermined distance.

[0031] (6) In the press die for a hat-shaped cross-sectional part according to any one of (1) to (5), the zenith forming portion is divided so as to be movable in the vertical direction with respect to the vertical wall forming portion, and is urged toward the pad side by an urging member attached to the fixed punch, the zenith forming portion is characterized by being connected to the first block member.

[0032] In the present invention, the zenith forming part is divided so as to be movable in the vertical direction with respect to the vertical wall forming part, and is biased toward the pad side by a biasing member attached to the fixed punch. Since the zenith forming part is connected to the first block member, when the movable punch is pushed by the pressing unit and moves from the separated position to the proximity position after the bending forming is completed, the movable punch presses the vertical wall part in a direction to release it from the fixed punch, and at the same time, the zenith forming part can press the zenith part in the same direction by the biasing force of the biasing member attached to the fixed punch. Therefore, when releasing the hat-shaped cross-sectional part after the bending forming from the fixed punch, it is possible to further avoid deformation of the vertical wall part of the hat-shaped cross-sectional part.

[0033] Further, since the zenith forming part is connected to the first block member, the distance control mechanism can be incorporated in the forming area of the fixed punch. In this case, it is not necessary to attach the distance control mechanism to both longitudinal ends of the fixed punch, the press die of this hat-shaped cross-sectional part can be formed more compactly, a steel plate can be stably placed on the zenith forming part, and its press workability can be improved.

[0034] (7) In the press die of the hat-shaped cross-sectional part described in (1), the zenith forming part is divided so as to be movable in the vertical direction with respect to the vertical wall forming part, and is biased toward the pad side by a biasing member attached to the fixed punch; the first block member is connected to the zenith forming part and is formed so as to be movable in the vertical direction by being pushed by the pad; the second block member is supported by the movable punch so as to be movable in the horizontal direction between the forward position and the retracted position, is vertically separated from the first block member at the retracted position, and is vertically in contact with the first block member at the forward position.

[0035] In the present invention, the zenith forming part is divided so as to be movable in the vertical direction with respect to the vertical wall forming part, and is biased toward the pad side by a biasing member attached to the fixed punch. The first block member is connected to the zenith forming part and is formed so as to be movable in the vertical direction by being pushed by the pad. The second block member is supported by the movable punch so as to be movable in the horizontal direction between the forward position and the retracted position, and is separated from the first block member in the vertical direction at the retracted position. Therefore, when the second block member is moved to the retracted position, the pad can press the steel plate against the zenith forming part in contact with the vertical wall forming part without being obstructed by the first block member during bending. Therefore, the pad can secure the necessary pressing force on the steel plate during bending and avoid warping of the zenith part in the hat-shaped cross-sectional part.

[0036] Further, since the second block member abuts on the first block member in the vertical direction at the forward position, the vertical relative distance between the movable punch and the pad can be easily fixed to a predetermined distance only by moving the second block member from the retracted position to the forward position.

[0037] Therefore, before the start of bending, by moving the second block member to the retracted position, the pad can secure the necessary pressing force on the steel plate during bending and easily avoid warping of the zenith part in the hat-shaped cross-sectional part. At the same time as the completion of bending, by moving the second block member from the retracted position to the forward position, it is possible to easily avoid deformation of the vertical wall part of the hat-shaped cross-sectional part after the completion of bending due to the pressing force of the pressing unit or the pressing force of the pad.

[0038] (8)(7) In the press die for the hat-shaped cross-sectional part described in, The mold base of the punch type is characterized by including a first cam part that moves the second block member from the retracted position to the forward position when the movable punch is pushed by the bending blade and moves from the proximity position to the separated position.

[0039] In the present invention, the punching die base is provided with a first cam portion that moves the second block member from the retracted position to the advanced position when the movable punch is pushed by the bending blade and moves from the proximity position to the separated position. Therefore, in conjunction with the movable punch being pushed by the bending blade and moving from the proximity position to the separated position, the first cam portion can surely move the second block member from the retracted position to the advanced position.

[0040] Therefore, the first block member that has been pushed by the pad and moved toward the die base side can come into contact with the second block member that has been moved to the advanced position by the first cam portion in the vertical direction, and can surely fix the vertical relative distance between the movable punch that has moved to the separated position and the pad to a predetermined distance. Then, after the bending forming is completed, when the movable punch is pushed by the pressing unit and moves from the separated position to the proximity position, the pad and the zenith forming portion move together with the movable punch in a state where the zenith portion is clamped vertically. As a result, it is possible to more stably avoid the vertical wall portion of the hat-shaped cross-sectional component sandwiched between the pad and the movable punch from being deformed by the pressing force of the pressing unit or the pressing force of the pad.

[0041] (9) In the press die for the hat-shaped cross-sectional component according to (7) or (8), The vertical stroke length of the first block member is formed longer than the amount of movement of the movable punch moving between the proximity position and the separated position. The first block member is provided with a second cam portion that moves the second block member from the advanced position to the retracted position when the pad separates from the zenith portion and the zenith forming portion is pushed by the biasing member and moves further toward the pad side after the movable punch moves from the separated position to the proximity position. The second block member is characterized by being provided with a passive cam portion that engages with the second cam portion.

[0042] In the present invention, the vertical stroke length of the first block member is formed to be longer than the moving amount by which the movable punch moves between the proximity position and the separated position. After the movable punch moves from the separated position to the proximity position, when the pad separates from the zenith portion and the zenith forming portion is pushed by the urging member and further moves toward the pad side, the first block member is provided with a second cam portion that moves the second block member from the forward position to the retracted position. Since the second block member is provided with a passive cam portion that engages with the second cam portion, when the pad separates from the zenith portion and moves to the mold opening position after the movable punch stops at the proximity position, the first block member connected to the zenith forming portion can further move by the difference between the stroke length of the first block member and the moving amount of the movable punch due to the urging force of the urging member. When the first block member further moves toward the pad side by the urging force of the urging member, the second cam portion of the first block member pushes the passive cam portion of the second block member, and the second block member can be automatically moved from the forward position to the retracted position.

[0043] Therefore, when bending and forming next, the second block member moved to the retracted position separates from the first block member in the vertical direction and does not restrict the relative vertical distance between the pad and the movable punch. Accordingly, in a state where the movable punch has moved to the proximity position by the pressing force of the pressing unit, with the pad pressing the steel plate against the zenith forming portion in contact with the vertical wall forming portion, the punch die and the die approach each other to bend and form the steel plate into a hat cross-sectional shape having a vertical wall portion standing up at the zenith portion and both sides thereof, and a step-shaped portion can be formed at the tip of the vertical wall portion by the bending blade and the movable punch. As a result, using the press die for this hat-shaped cross-section component, continuous press forming can be performed, the cycle time in the press forming of the hat-shaped cross-section component can be shortened, and its productivity can be further improved.

Effects of the Invention

[0044] According to the present invention, it is possible to provide a press die for a hat-shaped cross-sectional part that can reduce springback, warping, etc. occurring in the vertical wall part of the hat-shaped cross-sectional part, avoid deformation of the vertical wall part after bending forming without using a die cushion device with a locking mechanism of a press machine, and improve productivity.

Brief Description of the Drawings

[0045]

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Mode for Carrying Out the Invention

[0046] Next, an aspect of a press die for a hat-shaped cross-sectional component according to an embodiment of the present invention will be described in detail with reference to the drawings. First, the configuration and operation method of a press die for a hat-shaped cross-sectional component according to the first embodiment of the present embodiment will be described in detail. Thereafter, a modified example of the press die for the hat-shaped cross-sectional component and a modified example in the distance control mechanism will be described. Also, the configuration and operation method of a press die for a hat-shaped cross-sectional component according to the second embodiment of the present embodiment will be described centering on the differences from the first embodiment.

[0047] <Configuration and operating method of the press die for the hat-shaped cross-sectional part of the first embodiment> First, the configuration and operation method of the press die for the hat-shaped cross-sectional part of the first embodiment according to the present embodiment will be described in detail with reference to FIGS. 1 to 18. FIG. 1 shows a schematic perspective view of the hat-shaped cross-sectional part bent by the press die for the hat-shaped cross-sectional part according to the present embodiment. FIG. 2 shows a cross-sectional view of the press die for the hat-shaped cross-sectional part of the first embodiment according to the present embodiment, which is a cross-sectional view taken along line A-A shown in FIG. 1 at the start position of the bending forming. FIG. 3 shows a cross-sectional view of the press die for the hat-shaped cross-sectional part shown in FIG. 2 at the position immediately before die closing where the bending forming of the hat-shaped cross-sectional part is performed with the movable punch in the proximity position. FIG. 4 shows a cross-sectional view of the press die for the hat-shaped cross-sectional part shown in FIG. 2 at the die closing position where the movable punch moves from the proximity position to the separated position to apply a longitudinal tension to the vertical wall portion and the bending forming is completed. FIG. 5 shows a cross-sectional view of the press die for the hat-shaped cross-sectional part shown in FIG. 2 at the position immediately before die closing where the movable punch moves from the separated position to the proximity position after the bending forming is completed. FIG. 6 shows a cross-sectional view taken along line B-B shown in FIG. 4. FIG. 7 shows a cross-sectional view taken along line C-C shown in FIG. 6. FIG. 8 shows an exploded perspective view of the components of the distance control mechanism shown in FIG. 6. FIG. 9 shows a cross-sectional view of the detailed cross-sectional view of part D shown in FIG. 6 with the steel plate placed on the fixed punch before the start of the bending forming. FIG. 10 shows a cross-sectional view of the detailed cross-sectional view of part D shown in FIG. 6 with the steel plate placed on the fixed punch being pressed by the pad at the start of the bending forming. FIG. 11 shows a cross-sectional view of the detailed cross-sectional view of part D shown in FIG. 6 at the position immediately before die closing where the bending forming of the hat-shaped cross-sectional part is performed with the movable punch in the proximity position. FIG. 12 shows a cross-sectional view of the detailed cross-sectional view of part D shown in FIG. 6 during the movement of the movable punch pushed by the bending blade from the proximity position to the separated position. FIG. 13 shows a cross-sectional view of the detailed cross-sectional view of part D shown in FIG. 6 at the die closing position where the movable punch moves to the separated position and the bending forming of the hat-shaped cross-sectional part is completed. FIG. 14 shows a cross-sectional view of the detailed cross-sectional view of part D shown in FIG. 6 at the position immediately before die closing where the movable punch moves from the separated position to the proximity position after the bending forming is completed. FIG. 15 shows a cross-sectional view of the detailed cross-sectional view of part D shown in FIG. 6 during the further movement of the first block member following the pad with the movable punch stopped in the proximity position.Fig. 16 shows a cross-sectional view of the detailed cross-section of part D shown in Fig. 6, in a state where the first block member has stopped at the stop position on the pad side and the second block member has rotated to the fallen position. Fig. 17 shows a cross-sectional view of the cross-section shown in Fig. 6, in a state where the pad has separated from the hat-shaped cross-section component after the bending forming is completed. Fig. 18 is an operation explanatory view of the press die of the present hat-shaped cross-section component shown in Fig. 2. (a) shows an operation curve representing the change in the height of the die with respect to the punch die, and (b) shows an operation curve representing the change in the vertical relative distance between the pad and the movable punch.

[0048] (Configuration of the press die for the hat-shaped cross-section component of the first embodiment) As shown in Figs. 1 to 4, the press die 10 for the hat-shaped cross-section component of the first embodiment according to the present embodiment includes a fixed punch 11 fixed to the die base 13 and having a top forming portion 111 and a vertical wall forming portion 112 formed in a U-shaped cross-sectional shape, and a convex forming portion 121 and a flange forming portion 122 that project stepwise outward from the plate at the tip side of the vertical wall forming portion 112. The movable punch 12 is formed to be vertically movable between a proximity position K1 close to the fixed punch 11 and a separation position K2 separated from the fixed punch 11. The punch die 1 includes a pressure unit 14 supported by the die base 13 and pressing the movable punch 12 toward the fixed punch 11. The die 2 includes a bending blade 21 having a concave forming portion 211 formed to face the convex forming portion 121, and a pad 22 disposed on the inner peripheral side of the bending blade 21 and formed to be able to press the steel plate W against the top forming portion 111. In a state where the movable punch 12 has moved to the proximity position K1, the punch die 1 and the die 2 bend and form the steel plate W into a hat cross-sectional shape including a top portion M1 and vertical wall portions M2 standing on both sides thereof. At the same time, the bending blade 21 and the movable punch 12 bend and form the tip portion of the vertical wall portion M2 into a stepped portion M21. When the movable punch 12 is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2 while the bending blade 21 and the movable punch 12 hold the stepped portion M21, a longitudinal tension F is applied to the vertical wall portion M2 to complete the bending forming. This is the press die 10 for the hat-shaped cross-section component.

[0049] Here, the fixed punch 11 is fixed to the mold base 13 via a plurality of leg portions 11R that are intermittently arranged in the longitudinal direction. The movable punch 12 is integrally connected left and right in the gap between the leg portions 11R. Further, the pressing unit 14 includes a plurality of pressing pins 143 that abut against the movable punch 12, a movable plate 142 that supports the pressing pins 143 so as to be vertically movable, and a plurality of pressing springs 141 that are inserted between the movable plate 142 and a fixed plate 144 fixed to the mold base 13. Note that the pressing unit 14 may insert the pressing spring 141 into the mold base 13 and directly press the movable punch 12 with the pressing spring 141. Further, the movement amount d1 by which the movable punch 12 moves between the proximity position K1 and the separation position K2 is a minute distance (for example, about 2 to 5 mm) that can remove the difference in residual stress in the vertical wall portion M2.

[0050] Further, the pad 22 is provided with a plurality of pressing members (for example, a pressing cylinder that expands and contracts a cylinder rod 221R) 221 that press the steel plate W against the top forming portion 111 of the fixed punch 11. The pressing members 221 of the pad 22 are fixed to the mold base 23 of the die 2 to which the bending blade 21 is fixed. The pressing force P1 of the pressing member 221 is formed to be smaller than the pressing force P2 of the pressing unit 14.

[0051] Note that the hat-shaped cross-sectional component M is represented by, for example, vehicle member components arranged around the floor of an automobile, but is not particularly limited to vehicle member components. Further, as the steel plate W, a high-tensile steel plate having a tensile strength of about 590 to 980 Mpa can be used, but it is not particularly necessary to be limited to the above high-tensile steel plate. Further, the step-shaped portion M21 is preferably formed with the same cross-section along the longitudinal direction of the hat-shaped cross-sectional component M, but is not particularly limited to the same cross-section.

[0052] Also, as shown in FIGS. 5 to 17, in the press die 10 of the hat-shaped cross-sectional component, the punch die 1 is provided with a distance control mechanism 3 having a first block member 31 and a second block member 32 that control the vertical relative distance H between the movable punch 12 and the pad 22. And when the first block member 31 and the second block member 32 are separated in the vertical direction, the distance control mechanism 3 does not regulate the relative distance H. Until the movable punch 12 is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2, the first block member 31 and the second block member 32 are brought into contact with each other in the vertical direction, and the relative distance H is fixed at a predetermined distance H1 at the separation position K2. After the bending forming is completed, until the movable punch 12 is pushed by the pressing unit 14 and moves from the separation position K2 to the proximity position K1, the state where the first block member 31 and the second block member 32 are in contact with each other in the vertical direction is maintained. When the pad 22 separates from the zenith portion M1, the first block member 31 and the second block member 32 are formed to be separated in the vertical direction.

[0053] Therefore, after the punch die 1 and the die die 2 approach each other to bend the steel plate W into the hat-shaped cross-sectional component M and apply the longitudinal tension F to the longitudinal wall portion M2 to complete the bending forming, when the movable punch 12 is moved toward the fixed punch 11 side by the pressing force P2 of the pressing unit 14, it is possible to avoid deformation of the longitudinal wall portion M2 of the hat-shaped cross-sectional component M due to the pressing force P2 of the pressing unit 14 and the pressing force P1 of the pad 22.

[0054] Specifically, as shown in FIGS. 6 to 8, the punching die 1 is provided with a distance control mechanism 3 having a first block member 31 and a second block member 32 for controlling the vertical relative distance H between the movable punch 12 and the pad 22. Then, as shown in FIGS. 9 to 11 and FIGS. 15 to 17, when the first block member 31 and the second block member 32 are separated in the vertical direction, the distance control mechanism 3 does not regulate the relative distance H. After the bending forming is completed, when the pad 22 separates from the zenith portion M1, the first block member 31 and the second block member 32 are separated in the vertical direction. Therefore, in a state where the first block member 31 and the second block member 32 are separated in the vertical direction, the die 2 can move to the mold opening position and start the next bending forming. Therefore, at the start of the bending forming, with the pad 22 pressing the steel plate W against the zenith forming portion 111 in a state where the movable punch 12 has moved to the proximity position K1 by the pressing force P2 of the pressing unit 14, the punching die 1 and the die 2 approach each other, and the steel plate W is bent and formed into a hat cross-sectional shape having a zenith portion M1 and vertical wall portions M2 standing on both sides thereof, and the bending blade 21 and the movable punch 12 can form a stepped portion M21 at the tip of the vertical wall portion M2.

[0055] Also, as shown in FIGS. 12 and 13, until the movable punch 12 is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2, the distance control mechanism 3 brings the first block member 31 and the second block member 32 into contact with each other in the vertical direction to fix the relative distance H to a predetermined distance H1 at the separation position K2. Therefore, during the movement of the movable punch 12 from the proximity position K1 to the separation position K2 when it is pushed by the bending blade 21, the vertical relative distance H between the movable punch 12 and the pad 22 is not restricted. Thus, as shown in FIG. 4, with the pad 22 pressing the zenith portion M1 against the zenith forming portion 111 of the fixed punch 11, the bending blade 21 and the movable punch 12 grip the stepped portion M21 and apply a longitudinal tension F to the vertical wall portion M2 to remove the difference between the inner and outer sides of the plate in the residual stress in the vertical wall portion M2, thereby completing the bending forming. Also, as shown in FIG. 6, since the distance control mechanism 3 fixes the relative distance H to a predetermined distance H1 at the separation position K2 of the movable punch 12 with respect to the fixed punch 11, at the mold closing position of the punch die 1 and the die 2 where the bending forming is completed, the state of applying a longitudinal tension F to the vertical wall portion M2 can be maintained, and the shape can be frozen in a regular cross-sectional shape. Therefore, springback, warping, etc. occurring in the vertical wall portion M2 of the hat-shaped cross-section component M can be reduced.

[0056] Also, as shown in FIGS. 5 and 14, after the bending forming is completed, the distance control mechanism 3 maintains the state where the first block member 31 and the second block member 32 are in contact with each other in the vertical direction until the movable punch 12 is pushed by the pressurizing unit 14 and moves from the separation position K2 to the proximity position K1. Therefore, the pad 22 that sandwiches the hat-shaped cross-sectional component M in the vertical direction after the bending forming and the movable punch 12 can be simultaneously moved from the separation position K2 to the proximity position K1 of the movable punch 12 with respect to the fixed punch 11 while maintaining the relative distance H in the vertical direction at a predetermined distance H1. Further, as shown in FIGS. 15 to 17, when the pad 22 separates from the zenith portion M1, the distance control mechanism 3 separates the first block member 31 and the second block member 32 in the vertical direction. Therefore, even after the movable punch 12 stops at the proximity position K1, the pad 22 is restricted until the pad 22 separates from the zenith portion M1, and deformation of the vertical wall portion M2 of the hat-shaped cross-sectional component M due to the pressing force P1 of the pad 22 can be avoided. Therefore, deformation of the vertical wall portion M2 of the hat-shaped cross-sectional component M due to the pressing force P2 of the pressurizing unit 14 or the pressing force P1 of the pad 22 can be avoided.

[0057] Also, when moving the movable punch 12 to the proximity position K1 of the fixed punch 11 by the pressing force P2 of the pressurizing unit 14 after the bending forming is completed, the pad 22 and the movable punch 12 are simultaneously moved while maintaining the relative distance H in the vertical direction at a predetermined distance H1. Therefore, it is not necessary to use a pressurizing device equipped with a locking mechanism for temporarily stopping the movable punch 12 at the separation position K2 in the pressurizing unit 14. Therefore, the press machine that can use the press die 10 for this hat-shaped cross-sectional component is not limited to some press machines having a pressurizing device equipped with a locking mechanism. As a result, the arrangement of the press die 10 for this hat-shaped cross-sectional component is not limited to some press machines, and the degree of freedom and convenience of the arrangement can be improved. Further, after the bending forming is completed, it is not necessary to delay the moving timing for moving the movable punch 12 to the proximity position K1 of the fixed punch 11, the cycle time in the press forming of the hat-shaped cross-sectional component M can be shortened, and its productivity can also be improved.

[0058] Therefore, according to the press die 10 for the hat-shaped cross-sectional part, it is possible to reduce springback, warping, etc. occurring in the vertical wall portion M2 of the hat-shaped cross-sectional part M, and without using a die cushion device with a locking mechanism of a press machine, it is possible to provide a press die 10 for a hat-shaped cross-sectional part that can improve productivity while avoiding deformation of the vertical wall portion M2 after the bending forming is completed.

[0059] Also, as shown in FIGS. 6 to 17, in the press die 10 for the hat-shaped cross-sectional part of the present invention, the first block member 31 is supported by the fixed punch 11 so as to be movable in the vertical direction by being pushed by the pad 22, and the second block member 32 is supported by the movable punch 12 so as to be rotatable between the lying position L1 and the standing position L2, and is formed so as to be separated from the first block member 31 in the vertical direction at the lying position L1 and to abut against the first block member 31 in the vertical direction at the standing position L2.

[0060] In this case, the first block member 31 is supported by the fixed punch 11 so as to be movable in the vertical direction by being pushed by the pad 22, and the second block member 32 is supported by the movable punch 12 so as to be rotatable between the lying position L1 and the standing position L2, and is separated from the first block member 31 in the vertical direction at the lying position L1. Therefore, when the second block member 32 is rotated to the lying position L1, the pad 22 can press the steel plate W against the zenith forming portion 111 of the fixed punch 11 without being obstructed by the first block member 31 during the bending forming. Therefore, the pad 22 can secure the necessary pressing force P1 on the steel plate W during the bending forming and avoid warping, etc. of the zenith portion M1 in the hat-shaped cross-sectional part M.

[0061] Further, since the second block member 32 abuts against the first block member 31 in the vertical direction at the standing position L2, by simply rotating the second block member 32 from the lying position L1 to the standing position L2, the relative distance H in the vertical direction between the movable punch 12 and the pad 22 can be easily fixed to a predetermined distance H1.

[0062] Therefore, before starting the bending forming, by rotating the second block member 32 to the lying position L1, the necessary pressing force P1 of the pad 22 against the steel plate W during the bending forming can be ensured, and warping or the like of the apex M1 of the hat-shaped cross-sectional part M can be easily avoided. At the same time as the completion of the bending forming, by rotating the second block member 32 from the lying position L1 to the standing position L2, it is possible to easily avoid the vertical wall M2 of the hat-shaped cross-sectional part M after the completion of the bending forming from being deformed by the pressing force P2 of the pressing unit 14 and the pressing force P1 of the pad 22.

[0063] Also, as shown in FIGS. 12 and 13, in the press die 10 of the present hat-shaped cross-sectional part, the fixed punch 11 preferably includes a first cam portion 33 that rotates the second block member 32 from the lying position L1 to the standing position L2 when the movable punch 12 is pushed by the bending blade 21 and moves from the proximity position K1 to the separated position K2.

[0064] In this case, in conjunction with the movable punch 12 being pushed by the bending blade 21 and moving from the proximity position K1 to the separated position K2, the first cam portion 33 can reliably rotate the second block member 32 from the lying position L1 to the standing position L2. Therefore, the first block member 31 pushed by the pad 22 and moving toward the movable punch 12 side can come into contact with the second block member 32 rotated to the standing position L2 in the vertical direction, and the vertical relative distance H between the movable punch 12 that has moved to the separated position K2 and the pad 22 can be reliably fixed to a predetermined distance H1.

[0065] As a result, as shown in FIGS. 5 and 14, when the movable punch 12 is pushed by the pressing unit 14 and moves from the separated position K2 to the proximity position K1 after the completion of the bending forming, it is possible to stably avoid the vertical wall M2 of the hat-shaped cross-sectional part M sandwiched between the pad 22 and the movable punch 12 from being deformed by the pressing force P2 of the pressing unit 14 and the pressing force P1 of the pad 22.

[0066] Also, as shown in FIGS. 13 to 17, in the press die 10 of this hat-shaped cross-sectional part, the fixed punch 11 is provided with a biasing member (biasing spring) 34 that biases the first block member 31 toward the pad 22 side. The vertical stroke length d2 of the first block member 31 is formed longer than the movement amount d1 by which the movable punch 12 moves between the proximity position K1 and the separation position K2. After the movable punch 12 moves from the separation position K2 to the proximity position K1, the pad 22 separates from the zenith position M1, and when the first block member 31 is pushed by the biasing member 34 and moves further toward the pad 22 side, the first block member 31 is preferably provided with a second cam portion 311 that rotates the second block member 32 from the upright position L2 to the fallen position L1. The second block member 32 is preferably provided with a passive cam portion 321 that engages with the second cam portion 311.

[0067] In this case, after the movable punch 12 stops at the proximity position K1, when the pad 22 moves to the mold opening position, the first block member 31 can move further by the difference between the stroke length d2 of the first block member 31 and the movement amount d1 of the movable punch 12 due to the biasing force of the biasing member 43. Then, when the first block member 31 moves further toward the pad 22 side due to the biasing force of the biasing member 43, the second cam portion 311 of the first block member 31 pushes the passive cam portion 321 of the second block member 32, and the second block member 32 can be automatically rotated from the upright position L2 to the fallen position L1.

[0068] Therefore, when the next bending is performed, the second block member 32 rotated to the collapsed position L1 is vertically separated from the first block member 31, and the relative distance H between the pad 22 and the movable punch 12 is not restricted, so that the pad 22 presses the steel sheet W against the zenith forming portion 111 of the fixed punch 11 in a state in which the movable punch 12 approaches the approach position K1 by the pressing force P2 of the pressurizing unit 14, the punch mold 1 and the die mold 2 approach each other, and the steel sheet W is bent into a hat cross-sectional shape having the zenith portion M1 and the vertical wall portions M2 standing on both sides of the zenith portion M1, and the bending blade 21 and the movable punch 12 form the step-shaped portion M21 at the tip of the vertical wall portion M2. As a result, the press mold 10 for the hat cross-section part can be used for continuous press forming, the cycle time in press forming the hat cross-section part M can be shortened, and the productivity can be further improved.

[0069] 6, 8, 10, and 13, the distance control mechanism 3 is attached to both longitudinal ends 11a of the fixed punch 11. The distance control mechanism 3 includes a first block member 31 formed to be movable up and down with respect to the fixed punch 11, a biasing spring (biasing member) 34 that biases the first block member 31 toward the pad 22, a support plate 35 that supports the biasing spring 34 at both longitudinal ends 11a of the fixed punch 11, a first cam portion 33 and a stopper portion 37 fixed to the support plate 35, a second block member 32 formed to be rotatable between a laid-down position L1 and an upright position L2, and a support member 36 fixed to the movable punch 12 and rotatably supporting the second block member 32.

[0070] The first block member 31 includes a cylindrical portion 313 that comes into contact with the pad 22, an abutment seat 312 that comes into contact with the second block member 32, a second cam portion 311 that stands from the abutment seat 312 toward the second block member 32, and a rectangular flange portion 314 that comes into contact with the biasing spring 34. The support plate 35 is formed with a through hole 351 that allows the abutment seat 312 and the second cam portion 311 to pass through. The first cam portion 33 includes an inclined portion 331 that comes into contact with one side wall 325 of the second block member 32 in the laid position L1, and a vertical portion 332 that comes into contact with one side wall 325 of the second block member 32 in the upright position L2, and the inclined portion 331 and the vertical portion 332 intersect at an obtuse angle. The stopper portion 37 has an inclined portion 371 that comes into contact with the other side wall 326 of the second block member 32 in the laid-down position L1.

[0071] The second block member 32 is provided with a head portion 323 that abuts against the abutment seat 312 of the first block member 31, an arc-shaped passive cam portion 321 that engages with the second cam portion 311 at a position adjacent to the head portion 323, and a shaft portion 322 that protrudes toward the rotation center. The support member 36 is provided with a pair of support portions 361 that rotatably support the shaft portion 322 of the second block member 32, and a fixing portion 362 that fixes both support portions 361 to the movable punch 12. The legs 324 of the second block member 32 are formed in an arc shape so as not to interfere with the fixing portion 362 of the support member 36.

[0072] (How the press die for this hat-shaped cross-section part works) Next, we will explain the operation method of the press die 10 for this hat-shaped cross section part, with the punch die 1 as the lower die and the die die 2 as the upper die, as shown in Figure 18, when the die die 2 descends from the top dead center (die opening position) to the bottom dead center (die closing position) and then ascends to the top dead center (die opening position).

[0073] In Fig. 18(a), the vertical axis represents the height of die type 2 with respect to punch type 1, and the horizontal axis represents the rotation angle of the ram of the press machine that moves die type 2 up and down. In Fig. 18(b), the vertical axis represents the vertical relative distance H between pad 22 and movable punch 12, and the horizontal axis represents the rotation angle of the ram of the press machine that moves die type 2 up and down.

[0074] Here, height h2 indicates the height of die type 2 when pad 22 presses steel plate W against the zenith forming portion 111 of fixed punch 11 at the start of bending. Also, height h1 indicates the height of die type 2 when, with pad 22 pressing steel plate W against zenith forming portion 111, bending blade 21 bends steel plate W into a hat cross-sectional shape having a zenith portion M1 and vertical wall portions M2 standing up on both sides thereof, and the tip of vertical wall portion M2 is bent into step-shaped portion M21, and the die type 2 has descended to a position just before die closing (just before bottom dead center). Height h3 indicates the height of die type 2 when, after completion of bending, bending blade 21 has risen to a position where pad 22 is separated from zenith portion M1 of hat-shaped cross-section component M.

[0075] First, as shown in Figs. 2 and 9, after placing steel plate W on zenith forming portion 111 of fixed punch 11, die type 2 at the die-open position is lowered. At this time, movable punch 12 has risen to a proximity position K1 close to fixed punch 11 by the pressing force P2 of pressurizing unit 14. Also, first block member 31 has risen to rising ends 111a within both longitudinal ends 11a of fixed punch 11 being pushed by biasing spring 34. Also, second block member 32 has rotated to a fallen position L1 in contact with inclined portion 331 of first cam portion 33 and inclined portion 371 of stopper portion 37. Therefore, first block member 31 and second block member 32 are separated in the vertical direction and are not in contact.

[0076] Next, as shown in FIGS. 2 and 10, the die type 2 descends, and the pad 22 presses the steel plate W against the top forming portion 111 of the fixed punch 11. At this time, the cylindrical portion 313 of the first block member 31 is pushed by the pad 22 and descends to the descending end. However, since the second block member 32 is rotated to the lying position L1, the first block member 31 and the second block member 32 are separated in the vertical direction and are not in contact. Therefore, at this stage, the distance control mechanism 3 does not regulate the vertical relative distance H (H2) between the pad 22 and the movable punch 12, and can maintain the state in which the pad 22 presses the steel plate W against the top forming portion 111 of the fixed punch 11, and the movable punch 12 can maintain the state of rising to the proximity position K1.

[0077] Next, as shown in FIGS. 3 and 11, with the pad 22 pressing the steel plate W against the top forming portion 111 of the fixed punch 11, the die type 2 descends to a position immediately before die closing, forming a hat-shaped cross-sectional part M having a top portion M1 and vertical wall portions M2 standing on both sides thereof, and forming a step-shaped portion M21 at the tip of the vertical wall portion M2. At this time, since the second block member 32 is still rotated to the lying position L1, the first block member 31 and the second block member 32 are separated in the vertical direction and are not in contact. Therefore, the distance control mechanism 3 does not regulate the vertical relative distance H between the pad 22 and the movable punch 12, and can maintain the state in which the pad 22 presses the top portion M1 against the top forming portion 111 of the fixed punch 11, and the movable punch 12 can maintain the state of rising to the proximity position K1. Therefore, as shown in FIG. 18(b), the vertical relative distance H2 between the pad 22 and the movable punch 12 is maintained in a constant state. Also, the bending blade 21 and the movable punch 12 can sandwich the step-shaped portion M21.

[0078] Next, as shown in FIGS. 4, 6, 7, 12, and 13, when the die type 2 descends from the position immediately before die closing to the die closing position, with the pad 22 pressing the zenith portion M1 against the zenith forming portion 111 of the fixed punch 11, the movable punch 12 pushed by the bending blade 21 moves from the proximity position K1 to the separation position K2. At this time, while the bending blade 21 and the movable punch 12 sandwich the stepped portion M21, by applying a longitudinal tension F to the vertical wall portion M2, the bending forming is completed. Also, when the movable punch 12 moves from the proximity position K1 to the separation position K2, the first cam portion 33 presses one side wall 325 of the second block member 32, thereby rotating the second block member 32 from the lying position L1 to the standing position L2. The second block member 32 reaches a state of the standing position L2 when one side wall 325 of the second block member 32 and the vertical portion 332 of the first cam portion 33 come into contact when the movable punch 12 reaches the separation position K2. Then, the contact seat 312 of the first block member 31 pressed by the pad 22 and the head portion 323 of the second block member 32 in the standing position L2 come into contact in the vertical direction. Also, the second cam portion 311 of the first block member 31 and the passive cam portion 321 of the second block member 32 engage with each other. Therefore, as shown in FIG. 18(b), at the die closing position (bottom dead center) of the die type 2, the vertical relative distance H between the movable punch 12 that has moved to the separation position K2 and the pad 22 is fixed to a predetermined distance H1.

[0079] Next, as shown in FIGS. 5, 14, and 18(b), after the bending forming is completed, when the die type 2 ascends from the die closing position (bottom dead center) to the position immediately before die closing, the movable punch 12 pushed by the pressing force P2 of the pressing unit 14 moves from the separation position K2 to the proximity position K1 while fixing the vertical relative distance H from the pad 22 to the predetermined distance H1. At this time, the hat-shaped cross-sectional component M rises by the amount of movement d1 of the movable punch 12 with respect to the fixed punch 11, but since the pad 22 also rises by the amount of movement d1 of the movable punch 12, the vertical wall portion M2 of the hat-shaped cross-sectional component M is not deformed.

[0080] Next, as shown in FIGS. 15 to 17 and FIG. 18(b), when the die type 2 rises from the position just before die closing to the die opening position, after the cylinder rod 221R of the pressing cylinder 221 of the pad 22 extends to the extended end, the pad 22 separates from the zenith part M1 and rises in synchronization with the die type 2. When the pad 22 separates from the zenith part M1 and rises, the first block member 31 pushed by the pad 22 is pushed by the biasing spring 34 and rises to the rising end 111a in both longitudinal end portions 11a of the fixed punch 11. At this time, the second cam part 311 of the first block member 31 pushes out the passive cam part 321 of the second block member 32, rotates the second block member 32 to the falling position L1, and separates the first block member 31 and the second block member 32 in the vertical direction.

[0081] Based on the above operating method, when bending and forming next, the second block member 32 rotated to the falling position L1 separates from the first block member 31 in the vertical direction, and does not restrict the vertical relative distance H between the pad 22 and the movable punch 12. Therefore, with the pad 22 pressing the steel plate W against the zenith forming part 111 of the fixed punch 11 in a state where the movable punch 12 has moved to the proximity position K1 by the pressing force P2 of the pressing unit 14, the punch die 1 and the die type 2 approach each other to form the hat-shaped cross-sectional part M, and a step-shaped part M21 can be formed at the tip of the vertical wall part M2. As a result, continuous press forming can be performed using the press die 10 for this hat-shaped cross-sectional part.

[0082] <Modification Example> Needless to say, the present invention can be changed into various forms without changing the gist. For example, in the present embodiment, the punch die 1 is provided with a distance control mechanism 3 having a first block member 31 and a second block member 32 that control the vertical relative distance H between the movable punch 12 and the pad 22, and the distance control mechanism 3 is attached to both longitudinal end portions 11a of the fixed punch 11. And the first block member 31 is formed so as to directly contact the pad 22. However, the first block member 31 does not necessarily have to be formed so as to directly contact the pad 22.

[0083] For example, as shown in FIGS. 19 and 20, in the press die 10B for a hat-shaped cross-sectional part, the top forming part 111B is divided so as to be movable in the vertical direction with respect to the vertical wall forming part 112B, and is biased toward the pad 22 by a biasing member 113B attached to the fixed punch 11B. The top forming part 111B may be connected to the first block member 31B.

[0084] In this case, since the first block member 31B is connected to the top forming part 111B that is divided to be vertically movable, when the movable punch 12 is pushed by the pressing unit 14 and moves from the separated position K2 to the proximity position K1 after the bending forming is completed, the movable punch 12 presses the vertical wall part M2 in a direction to release it from the fixed punch 11B. At the same time, the top forming part 111B can press the top part M1 in the same direction by the biasing force of the biasing member 113B attached to the fixed punch 11B. Therefore, when releasing the hat-shaped cross-sectional part M after the bending forming from the fixed punch 11B, it is possible to further avoid the vertical wall part M2 of the hat-shaped cross-sectional part M from being deformed.

[0085] Also, since the top forming part 111B is connected to the first block member 31, the distance control mechanism 3B can be incorporated in the forming area of the fixed punch 11B. In this case, it is not necessary to attach the distance control mechanism 3B to both longitudinal ends 11a of the fixed punch 11, and the press die 10B for this hat-shaped cross-sectional part can be formed more compactly. Also, the steel plate W can be stably placed on the top forming part 111B, and the press workability can be improved.

[0086] Further, in the present embodiment, the first block member 31 is provided with a second cam part 311 that rotates the second block member 32 from the standing position L2 to the fallen position L1 when the movable punch 12 moves from the separated position K2 to the proximity position K1 and is further pushed by the biasing member 34 and moves toward the pad 22 side. The second block member 32 is provided with a passive cam part 321 that engages with the second cam part 311, but it is not necessarily limited to this.

[0087] For example, as shown in Figures 21 and 22, in a distance control mechanism 3C of a press die 10C for a hat-shaped cross-section part, a support member 36 that rotatably supports the second block member 32 is fixed to the movable punch 12, and the support member 36 and the second block member 32 are connected by a turnover spring 38. The turnover spring 38 may be arranged so that, when the second cam portion 311 moves away from the passive cam portion 321, a biasing force Q11 acts to rotate the second block member 32 to the collapsed position L1, and, when the second cam portion 311 abuts against the passive cam portion 321, a biasing force Q21 acts to rotate the second block member 32 to the upright position L2.

[0088] Here, the turnover spring 38 includes a circular winding portion 383 and a pair of legs 381, 382 extending from both ends of the circular winding portion 383. One leg 381 is engaged with the support portion 361 of the support member 36, and the other leg 382 is engaged with the vicinity of the passive cam portion 321 of the second block member 32 via a connecting rod 384. The turnover spring 38 is disposed on both the left and right sides of the second block member 32. When the second block member 32 rotates to a position where the second cam portion 311 and the passive cam portion 321 are separated or in contact with each other, the engagement positions of both legs 381, 382 and the rotation center CL of the second block member 32 are disposed on a straight line. In this state, the biasing force Q3 of the turnover spring 38 acts in the direction of the straight line, and does not act in a direction that rotates the second block member 32.

[0089] However, at the same time that the second cam portion 311 moves away from the passive cam portion 321, the turnover spring 38 exerts a biasing force Q11 (the rotational component of the biasing force Q1) on the second block member 32 to rotate it to the collapsed position L1. Therefore, when the first block member 31 moves further by the difference between the stroke length d2 and the movement amount d1 due to the biasing force of the biasing member 43, the second cam portion 311 pushes the passive cam portion 321 in the direction of moving away from it, and at the same time, the biasing force Q11 of the turnover spring 38 acts, thereby more reliably rotating the second block member 32 to the collapsed position L1.

[0090] Also, when the second cam portion 311 comes into contact with the passive cam portion 321, at the same time, the turnover spring 38 exerts a biasing force Q21 (the component of the biasing force Q2 in the rotational direction) that rotates the second block member 32 toward the upright position L2. As a result, the movable punch 12 moves from the proximity position K1 to the separation position K2. When the first cam portion 33 rotates the second block member 32 from the lying position L1 to the upright position L2, the second cam portion 311 comes into contact with the passive cam portion 321, and at the same time, the biasing force Q21 of the turnover spring 38 acts, enabling the second block member 32 to be rotated more reliably to the upright position L2.

[0091] Therefore, when the movable punch 12 is pushed by the pressurizing unit 14 and moves to the proximity position K1 to start bending forming, the first block member 31 and the second block member 32 can be separated more reliably in the vertical direction. Also, after the bending forming is completed, when the movable punch 12 is pushed by the pressing force P2 of the pressurizing unit 14 and moves from the separation position K2 to the proximity position K1 until the pad 22 separates from the zenith position M1, the first block member 31 and the second block member 32 can be brought into contact more reliably in the vertical direction, and the vertical relative distance H between the movable punch 12 and the pad 22 can be maintained in a state of a predetermined distance H1.

[0092] In this embodiment, the fixed punch 11 is provided with the first cam portion 33 that rotates the second block member 32 from the lying position L1 to the upright position L2 when the movable punch 12 is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2. However, it is not necessarily limited to this. For example, the fixed punch 11 may be equipped with an air blow device (not shown) that ejects compressed air in a direction that rotates the second block member 32 from the lying position L1 to the upright position L2 when the movable punch 12 is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2.

[0093] In addition, in this embodiment, the first block member 31 is provided with a second cam portion 311 that rotates the second block member 32 from the standing position L2 to the lying down position L1 when the movable punch 12 is pushed by the biasing member 34 to move further toward the pad 22 after moving from the separated position K2 to the close position K1, and the second block member 32 is provided with a passive cam portion 321 that engages with the second cam portion 311, but this is not necessarily limited to this. For example, an air blow device (not shown) that sprays compressed air in a direction to rotate the second block member 32 from the standing position L2 to the lying down position L1 may be attached to the fixed punch 11 after the movable punch 12 moves from the separated position K2 to the close position K1.

[0094] <Configuration and operation method of the press die for the hat-shaped cross section part of the second embodiment> Next, the configuration and operation method of the press die for the hat section part of the second embodiment according to the present embodiment will be described with reference to Figs. 23 to 26, focusing mainly on the differences from the first embodiment. Fig. 23 is a cross-sectional view of the press die for the hat section part of the second embodiment according to the present embodiment, in which the movable punch is in the proximity position before bending is started. Fig. 24 is a cross-sectional view of the press die for the present hat section part shown in Fig. 23, in which (a) shows a cross-sectional view at the start of bending with the movable punch in the proximity position, and (b) shows a cross-sectional view at a position immediately before closing the die for bending the hat section part with the movable punch in the proximity position. Fig. 25 is a cross-sectional view of the press die for the present hat section part shown in Fig. 23, in which (a) shows a cross-sectional view at a die closing position where the movable punch has moved to the separation position to complete bending the hat section part, and (b) shows a cross-sectional view at a position immediately before closing the die for moving the movable punch from the separation position to the proximity position after bending is completed. Figure 26 shows a cross-sectional view of the press die for the hat-shaped cross-section part shown in Figure 23, with (a) showing the movable punch stopped at a close position and the bending blade moving in a direction away from the movable punch with the pad pressing the zenith portion against the zenith forming portion, and (b) showing a cross-sectional view in which the movable punch is stopped at a close position, the pad moves away from the zenith portion, and the first block member moves further following the pad.

[0095] As shown in FIGS. 23 to 26, the press die 10D of the hat-shaped cross-sectional component of the second embodiment according to the present embodiment includes a fixed punch 11D fixed to the die base 13D and having a zenith forming portion 111D and a vertical wall forming portion 112D formed in a U-shaped cross-sectional shape, and a convex forming portion 121 and a flange forming portion 122 that project stepwise outward from the plate at the tip side of the vertical wall forming portion 112D. A movable punch 12D is formed to be vertically movable between a proximity position K1 close to the fixed punch 11D and a separation position K2 separated from the fixed punch 11D, and a pressing unit 14D supported by the die base 13D and pressing the movable punch 12D toward the fixed punch 11D. A punch die 1D having, a bending blade 21 having a concave forming portion 211 formed to face the convex forming portion 121, and a pad 22 disposed on the inner peripheral side of the bending blade 21 and formed to be able to press the steel plate W against the zenith forming portion 111D. A die 2 is provided. In a state where the movable punch 12D has moved to the proximity position K1, the punch die 1D and the die 2 are bent and formed into a hat cross-sectional shape including a zenith portion M1 and vertical wall portions M2 standing on both sides thereof in close proximity to the steel plate W, and the bending blade 21 and the movable punch 12D are formed. When the tip of the vertical wall portion M2 is bent into a stepped portion M21, and the bending blade 21 and the movable punch 12D hold the stepped portion M21 and the movable punch 12D is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2, a vertical tension F is applied to the vertical wall portion M2. The press die 10D of the hat-shaped cross-sectional component is formed so as to complete the bending forming.

[0096] Further, the punch type 1D is provided with a distance control mechanism 3D having a first block member 31D and a second block member 32D that control the vertical relative distance H between the movable punch 12D and the pad 22. When the first block member 31D and the second block member 32D are separated in the vertical direction, the distance control mechanism 3D does not regulate the relative distance H. Until the movable punch 12D is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2, the first block member 31D and the second block member 32D are brought into contact with each other in the vertical direction to fix the relative distance H to a predetermined distance H1 at the separation position K2. After the bending forming is completed, until the movable punch 12D is pushed by the pressing unit 14D and moves from the separation position K2 to the proximity position K1, the first block member 31D and the second block member 32D are maintained in a state of being in contact with each other in the vertical direction. When the pad 22 separates from the zenith portion M1, the first block member 31D and the second block member 32D are formed to be separated in the vertical direction. The pressing unit 14D is formed such that the pressing spring 141 inserted into the die base 13D directly presses the movable punch 12.

[0097] Thereby, after the punch type 1D and the die type 2D approach each other to bend the steel plate W into the hat-shaped cross-sectional part M and apply the longitudinal tension F to the vertical wall portion M2 to complete the bending forming, when the movable punch 12D is moved toward the fixed punch 11D by the pressing force P2 of the pressing unit 14D, it is possible to avoid the vertical wall portion M2 of the hat-shaped cross-sectional part M from being deformed by the pressing force P2 of the pressing unit 14D and the pressing force P1 of the pad 22. The above content is common to the press die 10 for the hat-shaped cross-sectional part of the first embodiment described above.

[0098] Also, the press die 10D of the hat-shaped cross-sectional part of the second embodiment is different from the first embodiment in the following aspects. That is, as shown in FIG. 23, the zenith forming part 111D is divided so as to be movable in the vertical direction with respect to the vertical wall forming part 112D, and is biased toward the pad 22 side by a biasing member 113D attached to the fixed punch 11D. Further, the first block member 31D is connected to the zenith forming part 111D and is formed so as to be movable in the vertical direction by being pushed by the pad 22. Here, the first block member 31D extends vertically from the central part in the width direction of the zenith forming part 111D through the fixed punch 11D and the movable punch 12D to the mold base 13D, and is formed in a cylindrical or prismatic shape. At the tip of the first block member 31D, stopper parts 316D that abut against the mold base 13D are formed at the upper and lower stroke ends.

[0099] Also, as shown in FIGS. 23 and 25, the second block member 32D is supported by the movable punch 12D so as to be movable in the horizontal direction between the forward position T1 and the retracted position T2, and is separated from the first block member 31D in the vertical direction at the retracted position T2. Here, on the movable punch 12D, a support plate 123D that supports the second block member 32D so as to be movable in the horizontal direction is formed. Further, a notch groove 315D having a horizontally formed contact seat 312D is formed in the middle part in the vertical direction of the first block member 31D. The contact seat 312D of the first block member 31D is formed so as to abut against the head 323D of the second block member 32D that has moved to the forward position T1 in the vertical direction.

[0100] With the above configuration, as shown in FIG. 24, when the second block member 32D has moved to the retracted position T2, the pad 22 can press the steel plate W against the top forming portion 111D in contact with the vertical wall forming portion 112D without being obstructed by the first block member 31D during bending. Therefore, the pad 22 can secure the necessary pressing force P1 on the steel plate W during bending and avoid warping or the like of the top portion M1 in the hat-shaped cross-sectional component M. Further, since the second block member 32D abuts on the first block member 31D in the vertical direction at the advanced position T1, the vertical relative distance H between the movable punch 12D and the pad 22 can be easily fixed to a predetermined distance H1 only by moving the second block member 32D from the retracted position T2 to the advanced position T1.

[0101] Therefore, before starting the bending, by moving the second block member 32D to the retracted position T2, the necessary pressing force P1 of the pad 22 on the steel plate W during bending can be secured, and warping or the like of the top portion M1 in the hat-shaped cross-sectional component M can be easily avoided. At the same time as the completion of the bending, by moving the second block member 32D from the retracted position T2 to the advanced position T1, it is possible to easily avoid the vertical wall portion M2 of the hat-shaped cross-sectional component M after the completion of the bending from being deformed by the pressing force P2 of the pressing unit 14 or the pressing force P1 of the pad 22.

[0102] Further, since the top forming portion 111D is connected to the first block member 31D, the distance control mechanism 3D can be incorporated into the forming area of the fixed punch 11D. In this case, it is not necessary to mount the distance control mechanism 3D at both longitudinal ends of the fixed punch 11D, and the press die 10D of this hat-shaped cross-sectional component can be formed more compactly. Further, the steel plate W can be stably placed on the top forming portion 111D, and the press workability can be improved.

[0103] Also, in the press die 10D of the hat-shaped cross-sectional part of the second embodiment, as shown in FIGS. 24 and 25, on the mold base 13D of the punch die 1D, when the movable punch 12D is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2, it is preferable to be provided with a first cam portion 33D that moves the second block member 32D from the retracted position T2 to the advanced position T1. Here, the first cam portion 33D has a front-end inclined surface 331D that abuts against the rear-end inclined surface 324D of the second block member 32D and is fixed to the movable punch side of the mold base 13D. In this case, in conjunction with the movable punch 12D being pushed by the bending blade 21 and moving from the proximity position K1 to the separation position K2, the front-end inclined surface 331D of the first cam portion 33D pushes out the rear-end inclined surface 324D of the second block member 32D, whereby the second block member 32D can be reliably moved from the retracted position T2 to the advanced position T1.

[0104] Therefore, the first block member 31D pushed by the pad 22 and moving toward the mold base 13D side can abut against the second block member 32D moved to the advanced position T1 by the first cam portion 33D in the vertical direction, and the vertical relative distance H between the movable punch 12D moved to the separation position K2 and the pad 22 can be reliably fixed to a predetermined distance H1. And after the bending forming is completed, when the movable punch 12D is pushed by the pressurizing unit 14 and moves from the separation position K2 to the proximity position K1, the pad 22 and the zenith forming portion 111D sandwich the zenith portion M1 in the vertical direction and move together with the movable punch 12D. As a result, it is possible to more stably avoid the vertical wall portion M2 of the hat-shaped cross-sectional part M sandwiched between the pad 22 and the movable punch 12D from being deformed by the pressing force P2 of the pressurizing unit 14 and the pressing force P1 of the pad 22.

[0105] Also, in the press die 10D of the hat-shaped cross-sectional part of the second embodiment, as shown in FIGS. 23 and 26, the vertical stroke length d2 of the first block member 31D is formed longer than the movement amount d1 by which the movable punch 12D moves between the proximity position K1 and the separation position K2. In the first block member 31D, after the movable punch 12D moves from the separation position K2 to the proximity position K1, when the pad 22 separates from the zenith portion M1 and the zenith forming portion 111D is pushed by the biasing member 113D and moves further toward the pad 22 side, it is preferable to include a second cam portion 311D that moves the second block member 32D from the forward position T1 to the retracted position T2. The second block member 32D preferably includes a passive cam portion 321D that engages with the second cam portion 311D.

[0106] In this case, after the movable punch 12D stops at the proximity position K1, when the pad 22 separates from the zenith portion M1 and moves to the mold opening position, the first block member 31D connected to the zenith forming portion 111D can move further by the difference between the stroke length d2 of the first block member 31D and the movement amount d1 of the movable punch 12D due to the biasing force of the biasing member 113D. Then, when the first block member 31D moves further toward the pad 22 side by the biasing force of the biasing member 113D, the second cam portion 311D of the first block member 31D pushes the passive cam portion 321D of the second block member 32D, and the second block member 32D can be automatically moved from the forward position T1 to the retracted position T2.

[0107] Therefore, when bending and forming next, the second block member 32D moved to the retracted position T2 is separated from the first block member 31D in the vertical direction, and does not restrict the vertical relative distance H between the pad 22 and the movable punch 12D. Therefore, in a state where the movable punch 12D has moved to the proximity position K1 by the pressing force P2 of the pressing unit 14D, the pad 22 presses the steel plate W against the zenith forming portion 111D in contact with the vertical wall forming portion 112D, and the punch die 1D and the die 2 approach each other to bend and form the steel plate W into a hat cross-sectional shape including a zenith portion M1 and vertical wall portions M2 standing on both sides thereof. The bending blade 21 and the movable punch 12D can form a stepped shape portion M21 at the tip of the vertical wall portion M2. As a result, using the press die 10D of this hat-shaped cross-sectional component, continuous press forming can be performed, the cycle time in the press forming of the hat-shaped cross-sectional component M can be shortened, and its productivity can be further improved.

[0108] (Operation method of the press die for this hat-shaped cross-sectional component) First, as shown in FIG. 23, after placing the steel plate W on the zenith forming portion 111D of the punch die 1D, the die 2 at the mold open position is moved in the mold closing direction. At this time, the movable punch 12D has moved to the proximity position K1 close to the fixed punch 11D by the pressing force P2 of the pressing unit 14D (pressing spring 141D). Further, the first block member 31D connected to the zenith forming portion 111D has been pushed by the urging member 113D and moved to the stroke end on the pad 22 side. Further, the second block member 32D has moved to the retracted position T2 where the rear end side inclined surface 324D abuts against the front end side inclined surface 331D of the first cam portion 33D. Therefore, the first block member 31D and the second block member 32D are separated in the vertical direction and not in contact.

[0109] Next, as shown in Fig. 24(a), the die type 2 moves, and the pad 22 presses the steel plate W against the top forming portion 111D of the fixed punch 11D. At this time, the first block member 31D is pushed by the pad 22 and moves toward the mold base 13D side. However, since the second block member 32D has moved to the retracted position T2, the first block member 31D and the second block member 32D are separated in the vertical direction and do not contact each other. Therefore, at this stage, the distance control mechanism 3D does not regulate the relative distance H in the vertical direction between the pad 22 and the movable punch 12D, and can maintain the state where the pad 22 presses the steel plate W against the top forming portion 111D where the vertical wall forming portion 112D abuts, and the movable punch 12D can maintain the state of moving to the proximity position K1.

[0110] Next, as shown in Fig. 24(b), with the pad 22 pressing the steel plate W against the top forming portion 111D, the die type 2 moves to a position immediately before mold closing to form a hat-shaped cross-sectional part M having a top portion M1 and vertical wall portions M2 standing up on both sides thereof, and a step-shaped portion M21 is formed at the tip of the vertical wall portion M2. At this time, since the second block member 32D has still moved to the retracted position T2, the first block member 31D and the second block member 32D are separated in the vertical direction and do not contact each other. Therefore, the distance control mechanism 3D does not regulate the relative distance H in the vertical direction between the pad 22 and the movable punch 12D, and can maintain the state where the pad 22 presses the top portion M1 against the top forming portion 111D, and the movable punch 12D can maintain the state of moving to the proximity position K1. Therefore, the bending blade 21 and the movable punch 12D can sandwich the step-shaped portion M21.

[0111] Next, as shown in FIG. 25(a), when the die 2 moves from the position immediately before die closing to the die closing position, the movable punch 12D pressed by the bending blade 21 moves from the proximity position K1 to the separation position K2 with the pad 22 pressing the zenith portion M1 against the zenith forming portion 111D. At this time, while the bending blade 21 and the movable punch 12D sandwich the stepped portion M21, by applying a longitudinal tension F to the vertical wall portion M2, the bending forming is completed. Also, when the movable punch 12D moves from the proximity position K1 to the separation position K2, the front end inclined surface 331D of the first cam portion 33D presses the rear end inclined surface 324D of the second block member 32D, thereby moving the second block member 32D from the retracted position T2 to the advanced position T1. When the movable punch 12D reaches the separation position K2, the second block member 32D engages the second cam portion 311D of the first block member 31D with the passive cam portion 321D and reaches the advanced position T1. Then, the contact seat 312D of the first block member 31D pressed by the pad 22 and moved to the stroke end on the die base side abuts against the head portion 323D of the second block member 32D in the vertical direction. Therefore, at the die closing position (bottom dead center) of the die 2, the vertical relative distance H between the movable punch 12D moved to the separation position K2 and the pad 22 is fixed to a predetermined distance H1.

[0112] Next, as shown in FIG. 25(b), after the bending forming is completed, when the die 2 moves from the die closing position (bottom dead center) to the position immediately before die closing, the movable punch 12D pressed by the pressing force P2 of the pressing unit 14D moves from the separation position K2 to the proximity position K1 while fixing the vertical relative distance H from the pad 22 to a predetermined distance H1. At this time, the hat-shaped cross-sectional component M moves by the movement amount d1 of the movable punch 12D with respect to the fixed punch 11D. However, since the pad 22 also moves by the movement amount d1 of the movable punch 12D, the vertical wall portion M2 of the hat-shaped cross-sectional component M is not deformed. Also, with the pad 22 and the zenith forming portion 111D sandwiching the zenith portion M1 vertically, when the movable punch 12D moves by the movement amount d1, even if the vertical wall portion M2 is springy and bites into the vertical wall forming portion 112D of the fixed punch 11D, the vertical wall portion M2 of the hat-shaped cross-sectional component M is difficult to deform during mold release.

[0113] Next, as shown in FIG. 26(a), when the die 2 moves from the position just before die closing to the die opening position, after the pressing cylinder 221 of the pad 22 extends to the stroke end, as shown in FIG. 26(b), the pad 22 moves in synchronization with the die 2. When the pad 22 moves away from the zenith portion M1 to the die opening position, the first block member 31D is pushed by the urging member 113D and further moves to the stroke end on the pad 22 side. At this time, the second cam portion 311D of the first block member 31D pushes out the passive cam portion 321D of the second block member 32D, and moves the second block member 32D to the retracted position T2.

[0114] Based on the above operation method, when bending and forming next, the second block member 32D that has moved to the retracted position T2 is separated from the first block member 31D in the vertical direction, and does not regulate the vertical relative distance H between the pad 22 and the movable punch 12D. Therefore, with the pad 22 pressing the steel plate W against the zenith forming portion 111D in a state where the movable punch 12D has moved to the proximity position K1 by the pressing force P2 of the pressing unit 14D, the punch die 1D and the die 2 approach each other to form the hat-shaped cross-sectional part M, and a step-shaped portion M21 can be formed at the tip of the vertical wall portion M2. As a result, continuous press forming can be performed using the press die 10D of this hat-shaped cross-sectional part.

[0115] <Operational Effects> As described in detail above, according to the press dies 10, 10B, 10C, 10D of the hat-shaped cross-sectional component according to the present embodiment, the punch dies 1, 1B, 1D are provided with a distance control mechanism 3, 3B, 3C, 3D having a first block member 31, 31B, 31D and a second block member 32, 32D for controlling the vertical relative distance H between the movable punches 12, 12D and the pad 22. When the first block members 31, 31B, 31D and the second block members 32, 32D are separated in the vertical direction, the distance control mechanisms 3, 3B, 3C, 3D do not regulate the relative distance H. Until the movable punches 12, 12D are pushed by the bending blade 21 and move from the proximity position K1 to the separation position K2, the first block members 31, 31B, 31D and the second block members 32, 32D are brought into contact with each other in the vertical direction to fix the relative distance H to a predetermined distance H1 at the separation position K2. After the bending forming is completed, until the movable punches 12, 12D are pushed by the pressurizing units 14, 14D and move from the separation position K2 to the proximity position K1, the state where the first block members 31, 31B, 31D and the second block members 32, 32D are in contact with each other in the vertical direction is maintained. When the pad 22 separates from the zenith M1, the first block members 31, 31B, 31D and the second block members 32, 32D are separated in the vertical direction. Therefore, after the punch dies 1, 1D and the die 2 are brought close to each other to bend the steel plate W into the hat-shaped cross-sectional component M and apply a longitudinal tension F to the vertical wall portion M2 to complete the bending forming, when the movable punches 12, 12D are moved toward the fixed punches 11, 11D by the pressing force P2 of the pressurizing units 14, 14D, it is possible to avoid the vertical wall portion M2 of the hat-shaped cross-sectional component M from being deformed by the pressing force P2 of the pressurizing units 14, 14D and the pressing force P1 of the pad 22.

[0116] That is, the punch types 1, 1B, and 1D are provided with a distance control mechanism 3, 3B, 3C, 3D having a first block member 31, 31B, 31D and a second block member 32, 32D for controlling the vertical relative distance H between the movable punches 12, 12D and the pad 22. When the first block member 31, 31B, 31D and the second block member 32, 32D are separated in the vertical direction, the distance control mechanism 3, 3B, 3C, 3D does not regulate the relative distance H. After the bending forming is completed, when the pad 22 separates from the zenith portion M1, the first block member 31, 31B, 31D and the second block member 32, 32D are separated in the vertical direction. Therefore, with the first block member 31, 31B, 31D and the second block member 32, 32D separated in the vertical direction, the die type 2 can move to the mold opening position and start the next bending forming. Therefore, at the start of the bending forming, with the pad 22 pressing the steel plate W without being obstructed by the first block member 31, 31B, 31D against the zenith forming portions 111, 111D in the state where the movable punches 12, 12D have moved to the proximity position K1 by the pressing force P2 of the pressing units 14, 14D, the punch types 1, 1B, 1D and the die type 2 approach each other, and the steel plate W is bent into a hat cross-sectional shape having a zenith portion M1 and vertical wall portions M2 standing on both sides thereof. The bending blade 21 and the movable punches 12, 12D can form a step-shaped portion M21 at the tip of the vertical wall portion M2.

[0117] Also, the distance control mechanisms 3, 3B, 3C, 3D cause the first block members 31, 31B, 31D and the second block members 32, 32D to contact each other in the vertical direction until the movable punches 12, 12D are pushed by the bending blade 21 and move from the proximity position K1 to the separation position K2, and fix the relative distance H to a predetermined distance H1 at the separation position K2. Therefore, during the movement of the movable punches 12, 12D from the proximity position K1 to the separation position K2 when being pushed by the bending blade 21, the vertical relative distance H between the movable punches 12, 12D and the pad 22 is not restricted. Thus, with the pad 22 pressing the zenith part M1 against the zenith forming parts 111, 111B, 111D of the fixed punches 11, 11B, 11D, the bending blade 21 and the movable punches 12, 12D grip the stepped part M21 and apply a longitudinal tension F to the vertical wall part M2, removing the difference between the inner and outer sides of the plate in the residual stress in the vertical wall part M2 and completing the bending forming. Also, since the distance control mechanisms 3, 3B, 3C, 3D fix the relative distance H to a predetermined distance H1 at the separation position K2 of the movable punches 12, 12D with respect to the fixed punches 11, 11B, 11D, at the mold closing position of the punch dies 1, 1B, 1D and the die 2 where the bending forming is completed, the state of applying the longitudinal tension F to the vertical wall part M2 can be maintained, and the shape can be frozen in a regular cross-sectional shape. Therefore, springback, warping, etc. occurring in the vertical wall part M2 of the hat-shaped cross-section component M can be reduced.

[0118] Further, after the bending forming is completed, the distance control mechanisms 3, 3B, 3C, 3D maintain the state in which the first block members 31, 31B, 31D and the second block members 32, 32D are in contact with each other in the vertical direction until the movable punches 12, 12D are pushed by the pressing units 14, 14D and move from the separated position K2 to the proximity position K1. Therefore, the pads 22 that sandwich the hat-shaped cross-sectional component M in the vertical direction after the bending forming and the movable punches 12, 12D can be simultaneously moved from the separated position K2 to the proximity position K1 with respect to the fixed punches 11, 11B, 11D while maintaining the relative distance H in the vertical direction at a predetermined distance H1. Further, when the pad 22 separates from the zenith portion M1, the distance control mechanisms 3, 3B, 3C, 3D separate the first block members 31, 31B, 31D and the second block members 32, 32D in the vertical direction. Therefore, even after the movable punches 12, 12D stop at the proximity position K1, the pad 22 is restricted until the pad 22 separates from the zenith portion M1, and deformation of the vertical wall portion M2 of the hat-shaped cross-sectional component M due to the pressing force P1 of the pad 22 can be avoided. Therefore, deformation of the vertical wall portion M2 of the hat-shaped cross-sectional component M due to the pressing force P2 of the pressing units 14, 14D or the pressing force P1 of the pad 22 can be avoided.

[0119] Also, when moving the movable punches 12 and 12D to the proximity position K1 of the fixed punches 11, 11B, and 11D by the pressing forces P2 of the pressing units 14 and 14D after the bending forming is completed, the pads 22 and the movable punches 12 and 12D are moved simultaneously while maintaining the relative distance H in the vertical direction at a predetermined distance H1. Therefore, it is not necessary to use a pressing device equipped with a locking mechanism for temporarily stopping the movable punches 12 and 12D at the separated position K2 for the pressing units 14 and 14D. As a result, the press machines that can use the press dies 10, 10B, 10C, and 10D of this hat-shaped cross-sectional part are not limited to some press machines equipped with a pressing device having a locking mechanism. Consequently, the arrangement of the press dies 10, 10B, 10C, and 10D of this hat-shaped cross-sectional part is not limited to some press machines, and the degree of freedom and convenience of the arrangement can be improved. Further, after the bending forming is completed, it is not necessary to delay the moving timing for moving the movable punches 12 and 12D to the proximity position K1 of the fixed punches 11, 11B, and 11D, the cycle time in the press forming of the hat-shaped cross-sectional part M can be shortened, and its productivity can also be improved.

[0120] Therefore, according to the press dies 10, 10B, 10C, and 10D of this hat-shaped cross-sectional part, it is possible to provide press dies 10, 10B, 10C, and 10D of a hat-shaped cross-sectional part that can reduce springback, warping, etc. occurring in the vertical wall portion M2 of the hat-shaped cross-sectional part M, avoid deformation of the vertical wall portion M2 after the bending forming is completed without using a die cushion device with a locking mechanism for a press machine, and improve productivity.

[0121] According to this embodiment, the first block members 31, 31B are supported by the fixed punches 11, 11B so as to be movable in the vertical direction when pressed by the pad 22, and the second block member 32 is supported by the movable punch 12 so as to be rotatable between the lying-down position L1 and the standing position L2, and is separated from the first block members 31, 31B in the vertical direction at the lying-down position L1. Therefore, when the second block member 32 is rotated to the lying-down position L1, the pad 22 can press the steel sheet W against the zenith forming portions 111, 111B of the fixed punches 11, 11B during bending without being hindered by the first block members 31, 31B. Therefore, the pad 22 can secure the necessary pressing force P1 against the steel sheet W during bending, and can avoid warping of the zenith portion M1 of the hat-shaped cross-section part M.

[0122] In addition, since the second block member 32 abuts the first block members 31, 31B in the vertical direction at the upright position L2, the relative distance H in the vertical direction between the movable punch 12 and the pad 22 can be easily fixed to a predetermined distance H1 by simply rotating the second block member 32 from the laid-down position L1 to the upright position L2.

[0123] Therefore, by rotating the second block member 32 to the laid-down position L1 before the start of bending, the pad 22 ensures the necessary pressing force P1 on the steel plate W during bending, and warping of the apex portion M1 of the hat-shaped cross-section part M can be easily avoided. Furthermore, by rotating the second block member 32 from the laid-down position L1 to the upright position L2 simultaneously with the completion of bending, deformation of the vertical wall portion M2 of the hat-shaped cross-section part M after bending is completed due to the pressing force P2 of the pressure unit 14 and the pressing force P1 of the pad 22 can be easily avoided.

[0124] Further, according to the present embodiment, the fixed punches 11 and 11B are provided with a first cam portion 33 that rotates the second block member 32 from the lying position L1 to the standing position L2 when the movable punch 12 is pushed by the bending blade 21 and moves from the proximity position K1 to the separation position K2. Therefore, in conjunction with the movement of the movable punch 12 being pushed by the bending blade 21 from the proximity position K1 to the separation position K2, the first cam portion 33 can reliably rotate the second block member 32 from the lying position L1 to the standing position L2.

[0125] Therefore, the first block members 31 and 31B that are pushed by the pad 22 and move toward the movable punch 12 side can come into contact with the second block member 32 rotated to the standing position L2 by the first cam portion 33 in the vertical direction, and can reliably fix the vertical relative distance H between the movable punch 12 that has moved to the separation position K2 and the pad 22 to a predetermined distance H1. As a result, after the bending forming is completed, when the movable punch 12 is pushed by the pressing unit 14 and moves from the separation position K2 to the proximity position K1, it is possible to stably avoid the vertical wall portion M2 of the hat-shaped cross-sectional component M sandwiched between the pad 22 and the movable punch 12 from being deformed by the pressing force P2 of the pressing unit 14 and the pressing force P1 of the pad 22.

[0126] Further, according to the present embodiment, the fixed punches 11, 11B are provided with a biasing member 34 that biases the first block members 31, 31B toward the pad 22. The vertical stroke length d2 of the first block members 31, 31B is formed to be longer than the movement amount d1 by which the movable punch 12 moves between the proximity position K1 and the separated position K2. The first block members 31, 31B are provided with a second cam portion 311 that rotates the second block member 32 from the standing position L2 to the fallen position L1 when the movable punch 12 moves from the separated position K2 to the proximity position K1 and then is pushed by the biasing member 34 and moves further toward the pad 22. The second block member 32 is provided with a passive cam portion 321 that engages with the second cam portion 311. Therefore, after the movable punch 12 stops at the proximity position K1, when the pad 22 moves to the mold opening position, the first block members 31, 31B can move further by the difference between the stroke length d2 of the first block members 31, 31B and the movement amount d1 of the movable punch 12 due to the biasing force of the biasing member 43. When the first block members 31, 31B move further toward the pad 22 due to the biasing force of the biasing member 43, the second cam portion 311 of the first block members 31, 31B can push the passive cam portion 321 of the second block member 32 and automatically rotate the second block member 32 from the standing position L2 to the fallen position L1.

[0127] Therefore, when bending and forming next, the second block member 32 rotated to the fallen position L1 is separated from the first block members 31, 31B in the vertical direction and does not restrict the vertical relative distance H between the pad 22 and the movable punch 12. Thus, with the pad 22 pressing the steel plate W against the fixed punches 11, 11B in a state where the movable punch 12 is close to the proximity position K1 by the pressing force P2 of the pressing unit 14, the punch dies 1, 1B and the die 2 approach each other to bend and form the steel plate W into a hat cross-sectional shape having a top portion M1 and vertical wall portions M2 standing on both sides thereof. The bending blade 21 and the movable punch 12 can form a stepped portion M21 at the tip of the vertical wall portion M2. As a result, using the press dies 10, 10B, 10C of this hat-shaped cross-sectional component, continuous press forming can be performed, the cycle time in the press forming of the hat-shaped cross-sectional component M can be shortened, and its productivity can be further improved.

[0128] Further, according to the present embodiment, a support member 36 that rotatably supports the second block member 32 is fixed to the movable punch 12, and the support member 36 and the second block member 32 are connected by a turnover spring 38. The turnover spring 38 is arranged such that a biasing force Q11 that rotates the second block member 32 to the fallen position L1 acts simultaneously with the second cam portion 311 separating from the driven cam portion 321. Therefore, when the first block members 31 and 31B further move by the difference between the stroke length d2 and the movement amount d1 due to the biasing force of the biasing member 43, the second cam portion 311 pushes the driven cam portion 321 in the separating direction, and at the same time, the biasing force Q11 of the turnover spring 38 acts, so that the second block member 32 can be rotated more reliably to the fallen position L1.

[0129] Also, the turnover spring 38 is arranged such that a biasing force Q21 that rotates the second block member 32 to the upright position L2 acts simultaneously with the second cam portion 311 coming into contact with the driven cam portion 321. Therefore, when the movable punch 12 moves from the proximity position K1 to the separation position K2 and the second block member 32 is rotated from the fallen position L1 to the upright position L2 by the first cam portion 33, the second cam portion 311 comes into contact with the driven cam portion 321, and at the same time, the biasing force Q21 of the turnover spring 38 acts, so that the second block member 32 can be rotated more reliably to the upright position L2.

[0130] Therefore, when the movable punch 12 is pushed by the pressing unit 14 and moves to the proximity position K1 to start the bending forming, the first block member 31 and the second block member 32 can be more reliably separated in the vertical direction. Further, after the bending forming is completed, when the movable punch 12 is pushed by the pressing force P2 of the pressing unit 14 and moves from the separation position K2 to the proximity position K1 until the pad 22 separates from the zenith portion M1, the first block member 31 and the second block member 32 can be more reliably brought into contact in the vertical direction, and the vertical relative distance H between the movable punch 12 and the pad 22 can be maintained in a state of a predetermined distance H1.

[0131] Also, according to the present embodiment, the top forming portion 111B is divided so as to be movable in the vertical direction with respect to the vertical wall forming portion 112B, and is biased toward the pad 22 by a biasing member 113B attached to the fixed punch 11B. Since the top forming portion 111B is connected to the first block member 31B, when the movable punch 12 is pushed by the pressing unit 14 and moves from the separated position K2 to the proximity position K1 after the bending forming is completed, the movable punch 12 presses the vertical wall portion M2 in a direction to release it from the fixed punch 11B. At the same time, the top forming portion 111B can press the top portion M1 in the same direction by the biasing force of the biasing member 113B attached to the fixed punch 11B. Therefore, when releasing the hat-shaped cross-sectional part M after the bending forming from the fixed punch 11B, it is possible to further avoid deformation of the vertical wall portion M2 of the hat-shaped cross-sectional part M.

[0132] Further, since the top forming portion 111B is connected to the first block member 31B, the distance control mechanism 3B can be incorporated in the forming region of the fixed punch 11B. In this case, it is not necessary to attach the distance control mechanism 3B to both longitudinal ends 11a of the fixed punch 11B. The press die 10B for this hat-shaped cross-sectional part can be formed more compactly, and the steel plate W can be stably placed on the top forming portion 111B, thereby improving the press workability.

[0133] Further, according to the present embodiment, the zenith forming portion 111D is divided so as to be movable in the vertical direction with respect to the vertical wall forming portion 112D, and is biased toward the pad 22 by a biasing member 113D attached to the fixed punch 11D. The first block member 31D is connected to the zenith forming portion 111D and is formed to be movable in the vertical direction by being pushed by the pad 22. The second block member 32D is supported by the movable punch 12D so as to be movable in the horizontal direction between the forward position T1 and the retracted position T2, and is separated from the first block member 31D in the vertical direction at the retracted position T2. Therefore, when the second block member 32D is moved to the retracted position T2, the pad 22 can press the steel plate W against the zenith forming portion 111D in contact with the vertical wall forming portion 112D without being obstructed by the first block member 31D during bending. Thus, the pad 22 can secure the necessary pressing force P1 on the steel plate W during bending and avoid warping or the like of the zenith portion M1 in the hat-shaped cross-sectional component M.

[0134] Further, since the second block member 32D abuts on the first block member 31D in the vertical direction at the forward position T1, the vertical relative distance H between the movable punch 12D and the pad 22 can be easily fixed to a predetermined distance H1 only by moving the second block member 32D from the retracted position T2 to the forward position T1.

[0135] Therefore, before the start of bending, by moving the second block member 32D to the retracted position T2, the pad 22 can secure the necessary pressing force P1 on the steel plate W during bending and easily avoid warping or the like of the zenith portion M1 in the hat-shaped cross-sectional component M. At the same time as the completion of bending, by moving the second block member 32D from the retracted position T2 to the forward position T1, it is possible to easily avoid deformation of the vertical wall portion M2 of the hat-shaped cross-sectional component M after bending due to the pressing force P2 of the pressing unit 14D or the pressing force P1 of the pad 22.

[0136] Also, according to the present embodiment, the punch-type 1D die base 13D is provided with a first cam portion 33D that moves the second block member 32D from the retracted position T2 to the advanced position T1 when the movable punch 12D is pushed by the bending blade 21 and moves from the proximity position K1 to the separated position K2. Therefore, in conjunction with the movable punch 12D being pushed by the bending blade 21 and moving from the proximity position K1 to the separated position K2, the first cam portion 33D can reliably move the second block member 32D from the retracted position T2 to the advanced position T1.

[0137] Therefore, the first block member 31D pushed by the pad 22 and moved toward the die base 13D side can come into contact with the second block member 32D moved to the advanced position T1 by the first cam portion 33D in the vertical direction, and the vertical relative distance H between the movable punch 12D moved to the separated position K2 and the pad 22 can be reliably fixed to a predetermined distance H1. Then, after the bending forming is completed, when the movable punch 12D is pushed by the pressurizing unit 14D and moves from the separated position K2 to the proximity position K1, the pad 22 and the zenith forming portion 111D move together with the movable punch 12D while sandwiching the zenith portion M1 in the vertical direction. As a result, the vertical wall portion M2 of the hat-shaped cross-sectional component M sandwiched between the pad 22 and the movable punch 12D can be more stably prevented from being deformed by the pressing force P2 of the pressurizing unit 14D and the pressing force P1 of the pad 22.

[0138] Further, according to the present embodiment, the vertical stroke length d2 of the first block member 31D is formed longer than the movement amount d1 by which the movable punch 12D moves between the proximity position K1 and the separation position K2. After the movable punch 12D moves from the separation position K2 to the proximity position K1, when the pad 22 separates from the zenith portion M1 and the zenith forming portion 111D is pushed by the biasing member 113D and further moves toward the pad 22 side, the first block member 31D is provided with a second cam portion 311D that moves the second block member 32D from the forward position T1 to the retracted position T2. Since the second block member 32D is provided with a passive cam portion 321D that engages with the second cam portion 311D, when the pad 22 separates from the zenith portion M1 and moves to the mold opening position after the movable punch 12D stops at the proximity position K1, the first block member 31D connected to the zenith forming portion 111D can move further by the difference between the stroke length d2 of the first block member 31D and the movement amount d1 of the movable punch 12D due to the biasing force of the biasing member 113D. Then, when the first block member 31D further moves toward the pad 22 side due to the biasing force of the biasing member 113D, the second cam portion 311D of the first block member 31D pushes the passive cam portion 321D of the second block member 32D, and the second block member 32D can be automatically moved from the forward position T1 to the retracted position T2.

[0139] Therefore, when performing the next bending forming, the second block member 32D moved to the retracted position T2 separates from the first block member 31D in the vertical direction and does not restrict the vertical relative distance H between the pad 22 and the movable punch 12D. Accordingly, in a state where the movable punch 12D is moved to the proximity position K1 by the pressing force P2 of the pressing unit 14D, with the pad 22 pressing the steel plate W against the zenith forming portion 111D in contact with the vertical wall forming portion 112D, the punch die 1D and the die 2 approach each other to bend the steel plate W into a hat cross-sectional shape including the zenith portion M1 and the vertical wall portions M2 standing on both sides thereof. The bending blade 21 and the movable punch 12D can form a stepped portion M21 at the tip of the vertical wall portion M2. As a result, using the press die 10D for this hat-shaped cross-section component, continuous press forming can be performed, the cycle time in the press forming of the hat-shaped cross-section component M can be shortened, and its productivity can be further improved.

Industrial Applicability

[0140] The present invention can be used as a press die for hat-shaped cross-section parts that press-form a steel plate into a hat-shaped cross-section.

Explanation of Signs

[0141] 1, 1B, 1D Punch Type 2 Die Type 3, 3B, 3C, 3D Distance Control Mechanism 10A, 10B, 10C, 10D Press Die for Hat-Shaped Cross-Section Parts 11, 11B, 11D Fixed Punch 12, 12D Movable Punch 13, 13D Die Base 14, 14D Pressing Unit 21 Bending Blade 22 Pad 31, 31B, 31D First Block Member 32, 32D Second Block Member 33, 33D First Cam Portion 34 Biasing Member 36 Support Member 38 Turnover Spring 111, 111B, 111D Zenith Forming Portion 112, 112B, 112D Vertical Wall Forming Portion 113B, 113D Biasing Member 121 Convex Forming Portion 122 Flange Forming Portion 211 Concave Forming Portion 311, 311D Second Cam Portion 321, 321D Passive Cam Portion d1 Movement Amount d2 Stroke Length F Tension H Relative Distance H1 Predetermined Distance K1 Proximity Position K2 Separation Position L1 Toppling Position L2 Upright Position M Hat-Shaped Cross-Section Part M1 top part M2 vertical wall part M21 step-shaped part Q11, Q21 biasing force T1 forward position T2 retracted position W steel plate

Claims

1. A fixed punch having a top forming portion and a vertical wall forming portion that are fixed to a mold base and formed in a U-shaped cross-sectional shape, and a convex forming portion and a flange forming portion that project stepwise outward from the plate at the tip side of the vertical wall forming portion, and are formed to be vertically movable between a proximity position close to the fixed punch and a separation position separated from the fixed punch; a punch die having a pressing unit supported by the mold base for pressing the movable punch toward the fixed punch side; A bending blade having a concave forming portion formed to face the convex forming portion, and a die having a pad disposed on the inner peripheral side of the bending blade and formed to be able to press a steel plate against the top forming portion; In a state where the movable punch has moved to the proximity position, the punch die and the die are bent and formed into a hat cross-sectional shape having a top portion and vertical wall portions standing on both sides thereof by approaching each other, and the bending blade and the movable punch bend and form the tip portion of the vertical wall portion into a stepped shape portion; A press die for a hat-shaped cross-sectional component formed such that when the bending blade and the movable punch hold the stepped shape portion and the movable punch is pushed by the bending blade and moves from the proximity position to the separation position, a longitudinal tension is applied to the vertical wall portion to complete the bending forming; The punch die is provided with a distance control mechanism having a first block member and a second block member for controlling the vertical relative distance between the movable punch and the pad; The distance control mechanism is In a state where the first block member and the second block member are separated in the vertical direction, the relative distance is not restricted; Before the movable punch is pushed by the bending blade and moves from the proximity position to the separation position, the first block member and the second block member are brought into contact with each other in the vertical direction to fix the relative distance to a predetermined distance at the separation position, and after the bending forming is completed, until the movable punch is pushed by the pressing unit and moves from the separation position to the proximity position, the first block member and the second block member are maintained in a state of being in contact with each other in the vertical direction; When the pad is separated from the top portion, the first block member and the second block member are separated from each other in the vertical direction; The first block member is supported by the fixed punch so as to be movable in the vertical direction by being pushed by the pad; The second block member is rotatably supported by the movable punch between a fallen position and an upright position, is vertically spaced from the first block member at the fallen position, and abuts on the first block member in the vertical direction at the upright position. A press die for hat-shaped cross-sectional parts, characterized in that.

2. In the press die for hat-shaped cross-sectional parts according to claim 1, The fixed punch is provided with a first cam portion that rotates the second block member from the fallen position to the upright position when the movable punch is pushed by the bending blade and moves from the proximity position to the separation position. A press die for hat-shaped cross-sectional parts, characterized in that.

3. In the press die for hat-shaped cross-sectional parts according to claim 2, The fixed punch is provided with a biasing member that biases the first block member toward the pad side, The vertical stroke length of the first block member is formed longer than the movement amount of the movable punch moving between the proximity position and the separation position, The first block member is provided with a second cam portion that rotates the second block member from the upright position to the fallen position when the movable punch moves from the separation position to the proximity position and is pushed by the biasing member to further move toward the pad side, The second block member is provided with a passive cam portion that engages with the second cam portion. A press die for hat-shaped cross-sectional parts, characterized in that.

4. In the press die for hat-shaped cross-sectional parts according to claim 3, A support member that rotatably supports the second block member is fixed to the movable punch, and the support member and the second block member are connected by a turnover spring, The turnover spring is arranged such that when the second cam portion separates from the passive cam portion, a biasing force that rotates the second block member to the fallen position acts, and when the second cam portion abuts on the passive cam portion, a biasing force that rotates the second block member to the upright position acts. A press die for hat-shaped cross-sectional parts, characterized in that.

5. In the press die for hat-shaped cross-sectional parts according to any one of claims 1 to 4, The zenith forming portion is divided so as to be movable in the vertical direction with respect to the vertical wall forming portion, and is biased toward the pad side by a biasing member attached to the fixed punch. The press die for a hat-shaped cross-sectional part, wherein the zenith forming part is connected to the first block member. **Claim 6**: A fixed punch having a zenith forming part and a vertical wall forming part that are fixed to a die base and formed in a U-shaped cross-sectional shape, and a convex forming part and a flange forming part that project stepwise outward from the plate at the tip side of the vertical wall forming part, and a movable punch that is formed to be vertically movable between a proximity position close to the fixed punch and a separation position separated from the fixed punch, and a punch die having a pressurizing unit that is supported by the die base and pressurizes the movable punch toward the fixed punch. A bending blade having a concave forming part formed to face the convex forming part, and a die having a pad that is disposed on the inner peripheral side of the bending blade and is formed to be able to press a steel plate against the zenith forming part. In a state where the movable punch has moved to the proximity position, the punch die and the die are bent and formed into a hat cross-sectional shape having a zenith part and vertical wall parts standing on both sides thereof by approaching each other, and the bending blade and the movable punch bend and form the tip part of the vertical wall part into a stepped shape part. A press die for a hat-shaped cross-sectional part, wherein the bending blade and the movable punch are formed such that when the movable punch is pushed by the bending blade and moves from the proximity position to the separation position while gripping the stepped shape part, a longitudinal tension is applied to the vertical wall part to complete the bending forming. The punch die is provided with a distance control mechanism having a first block member and a second block member that control the vertical relative distance between the movable punch and the pad. The distance control mechanism is as follows: When the first block member and the second block member are separated in the vertical direction, the relative distance is not regulated. Before the movable punch is pushed by the bending blade and moves from the proximity position to the separation position, the first block member and the second block member are brought into contact with each other in the vertical direction to fix the relative distance to a predetermined distance at the separation position, and after the bending forming is completed, until the movable punch is pushed by the pressurizing unit and moves from the separation position to the proximity position, the state where the first block member and the second block member are in contact with each other in the vertical direction is maintained. When the pad is separated from the zenith part, the first block member and the second block member are separated from each other in the vertical direction. The zenith forming part is divided so as to be movable in the vertical direction with respect to the vertical wall forming part, and is biased toward the pad side by a biasing member attached to the fixed punch. The first block member is connected to the zenith forming part and is formed so as to be movable in the vertical direction by being pushed by the pad. The second block member is supported by the movable punch so as to be movable in the horizontal direction between a forward position and a retracted position, is vertically spaced from the first block member at the retracted position, and abuts the first block member vertically at the forward position. A press die for hat-shaped cross-sectional parts.

7. In the press die for hat-shaped cross-sectional parts according to claim 6, The die base of the punch type is provided with a first cam part for moving the second block member from the retracted position to the forward position when the movable punch is pushed by the bending blade and moves from the proximity position to the separated position. A press die for hat-shaped cross-sectional parts.

8. In the press die for hat-shaped cross-sectional parts according to claim 6 or claim 7, The vertical stroke length of the first block member is formed longer than the amount of movement of the movable punch moving between the proximity position and the separated position. The first block member is provided with a second cam part for moving the second block member from the forward position to the retracted position when the pad separates from the zenith part and the zenith forming part is pushed by the biasing member and moves further toward the pad side after the movable punch moves from the separated position to the proximity position. The second block member is provided with a passive cam part that engages with the second cam part. A press die for hat-shaped cross-sectional parts.

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