DIE DEVICE

Abstract

There is provided a die device capable of reliably releasing a workpiece from a die even when the workpiece has an undercut, and conveying the workpiece to a next process. A die device including: a lower die; and a lifter that lifts a pressed workpiece from the lower die, the lower die having an undercut region which is a portion that interferes with the workpiece when the workpiece is moved along a press direction, the lifter including: a vacuum cup that comes into contact with the workpiece; a rod part having a distal end provided with the vacuum cup; and a linear drive servomotor for causing the rod part to advance/retreat in an axial direction, and further including a rotary drive servomotor that turns the lifter in a direction orthogonal to the axial direction, wherein the lifter moves the workpiece by combining both movement along the press direction and movement in a direction inclined to the press direction.

Description

This application is based on and claims the benefit of priority from Japanese Patent Application No. 2020-058115, filed on 27 Mar. 2020, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a die device.

Related Art

When a pressed product is formed, a workpiece is formed by using a movable punch from the direction intersecting with the mold clamping direction using a cam driver or the like, so that the workpiece is formed in an undercut shape with respect to the die clamping direction. At that time, a movable die for forming an undercut portion is retreated, and the workpiece is released from a lower die (for example, Japanese Unexamined Patent Application, Publication No. 2013-078777).

Generally, in a case where an automobile body part is formed by press forming, the automobile body part is formed through a plurality of processes such as draw forming, trim forming, bend forming, and piercing forming. In this case, a plurality of dies are required, and therefore it is conceivable to integrate the processes and reduce the installation area of the equipment, and integrate the plurality of dies to perform, for example, draw forming, bend forming, and trim forming, by one die. In such a die, it is not possible to provide a space in a lower die for sufficiently retreating a movable die (movable die) that avoids an undercut, and there is a possibility that the workpiece cannot be released from a die.

Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2013-078777

SUMMARY OF THE INVENTION

An object of the present invention is to provide a die device capable of reliably releasing a workpiece from a die even when the workpiece has an undercut, and conveying the workpiece to a next process.

The present invention solves the aforementioned problem by the following solutions. In order to facilitate understanding, description will be made with reference numerals corresponding to embodiments of the present invention, but the description is not limited to the embodiments.

A first aspect of the invention relates to a die device (1) including:

• • a lower die (10); and
  • a lifter (20, 20B) that lifts a pressed workpiece (W) from the lower die (10), the lower die (10) having an undercut region which is a portion that interferes with the workpiece (W) when the workpiece is moved along a press direction, the lifter (20, 20B) including: an abutting part (27, 206) that comes into contact with the workpiece (W); a rod part (23a, 204a) having a distal end provided with the abutting part (27, 206); and a driving means (24, 205) for causing the rod part (23a, 204a) to advance/retreat in an axial direction, the die device further including a turning drive part (25, 201a, 202a) that turns the lifter (20, 20B) in a direction orthogonal to the axial direction, wherein the lifter (20, 20B) moves the workpiece (W) by combining both movement along the press direction and movement in a direction inclined to the press direction.

According to a second aspect of the invention, in the die device (1) described in the first invention, the undercut region of the lower die (10) includes:

a movable die part (12) that moves in such a direction as to release an undercut; and a fixed die part (11) having a portion that remains as an undercut in relation with the workpiece (W) even in a state in which the movable die part (12) moves to perform release.

According to a third aspect of the invention, in the die device (1) described in the first invention or the second invention, the abutting part (27, 206) is provided with a vacuum cup (27, 206).

According to a fourth aspect of the invention, the die device (1) described in any of the first invention to the third invention further includes support lifters (30) that advance and retreat in a direction along the press direction,

wherein the support lifters (30) are provided in at least each one of a turning direction and a counter-turning direction of the lifter (20, 20B) with the lifter (20, 20B) interposed therebetween, the die device (1) including a control device (40) that controls protrusion positions of the support lifters (30) in accordance with turning operation of the lifter (20, 20B).

According to a fifth aspect of the invention, in the die device (1) described in the fourth invention, the support lifters (30) are each provided with a sliding member (33) for enhancing sliding performance between the workpiece (W) and the support lifter, at a portion that comes into contact with the workpiece (W).

According to the present invention, it is possible to provide a die device capable of reliably releasing a workpiece even when the workpiece has an undercut, and transporting the workpiece to a next process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a first embodiment of a die device 1 according to the present invention;

FIG. 2 is a perspective view of a lifter 20;

FIG. 3 is a perspective view of a support lifter 30;

FIG. 4 is a block diagram illustrating an outline of a control block of the die device 1;

FIG. 5 is a sectional view of a lower die 10 and a workpiece W cut at the position of the arrows A-A in FIG. 1;

FIG. 6 is a diagram illustrating a state in which a movable die part 12 moves in such a direction as to release an undercut;

FIG. 7 is a diagram illustrating a state in which the workpiece W is moved upward in the press direction;

FIG. 8 is a diagram illustrating a state in which the workpiece W is turned;

FIG. 9 illustrates a state in which the workpiece W is raised in the oblique direction from a position where the workpiece W is turned;

FIG. 10 is a perspective view illustrating a lifter 20B of a second embodiment;

FIG. 11 is a sectional view illustrating the lifter 20B of the second embodiment; and

FIGS. 12A to 12F are diagrams illustrating operation processes of the lifter 20B, the operation processes being arranged in order.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings and the like.

First Embodiment

FIG. 1 is a diagram illustrating a first embodiment of a die device 1 according to the present invention. Each figure illustrated below including FIG. 1 is a diagram schematically illustrated, and the size and the shape of each part are illustrated by being appropriately exaggerated or omitted in order to facilitate understanding. In the following description, specific numerical values, shapes, materials and the like will be described, but these can be appropriately changed.

The die device 1 of the first embodiment includes a lower die 10 and an upper die (not illustrated), and is used for press forming of a vehicle outer plate. In this embodiment, the die device used for press forming of the vehicle outer panel is described as an example. However, a workpiece to be press-formed may be of other application. The lower die 10 is provided with a male die part 11 of the vehicle outer plate that constitutes the vicinity of a central portion of a side surface of a vehicle. Further, lifters 20 and support lifters 30 are disposed in the male die part 11.

The lifters 20 lift the pressed workpiece W from the lower die. The lifters 20 of this embodiment are disposed at two locations, a B-pillar portion located at a central portion of a vehicle body and a rear fender portion. In this embodiment, the lifters 20 disposed at the aforementioned two locations are disposed at positions where the center of gravity of the workpiece W is interpose, and therefore the workpiece W can be raised in a well-balanced manner when the workpiece W is raised.

FIG. 2 is a perspective view of each lifter 20. The lifter 20 includes a base part 21, a support member 22, a cylinder body 23, a linear drive servomotor 24, a rotary drive servomotor 25, a speed reducer 26, and a vacuum cup 27.

The base part 21 is attached to the lower die 10, or a bolster or the like that supports the lower die 10, and is fixed so as not to move relative to the lower die 10.

The support member 22 is attached so as to be turnable (swingable) with respect to the base part 21. The cylinder body 23 is fixed to the support member 22, and a rod part 23a that advances and retreats from the cylinder body 23 movably penetrates the support member 22.

An upper portion of the cylinder body 23 is fixed to the support member 22, and the cylinder body 23 can turn (swing) with respect to the base part 21 together with the support member 22. The rod part 23a advances and retreats upward from the cylinder body 23.

The linear drive servomotor 24 is attached to the cylinder body 23, and is a driving means for causing the rod part 23a to advance and retreat in the axial direction under control of a control device 40 described later.

The rotary drive servomotor 25 is fixed to the base part 21 via the speed reducer 26. An output shaft (not illustrated) of the rotary drive servomotor 25 is connected to the support member 22 via an input shaft and an output shaft (both not illustrated) of the speed reducer 26. Consequently, the rotary drive servomotor 25 functions as a turning drive part that is controlled by the control device 40 described later to turn (swing) the support member 22 and the cylinder body 23 with respect to the base part 21. This turning (swing) direction is the direction orthogonal to the axial direction of the rod part 23a.

The speed reducer 26 reduces rotational driving force of the rotary drive servomotor 25 to transmit driving force for rotationally driving the support member 22.

The vacuum cup 27 is attached to a tip of the rod part 23a, and has a function as an abutting part that abuts on the workpiece W. The vacuum cup 27 is formed in a suction cup shape by an elastic body such as elastomer. Further, the vacuum cup 27 has a pipe (not illustrated) connected to a pressure regulator (not illustrated), and is depressurized to suck and hold the workpiece W. The abutting part of the lifter 20 is not limited to the vacuum cup, and other means such as magnetic force may be used.

With the above configuration, the lifters 20 can hold and lift (lift up) the workpiece W in accordance with the control of the control device 40, and further turn (swing) the held workpiece W.

Returning to FIG. 1, a plurality of the support lifters 30 are disposed in a region where the lifters 20 are not provided, and in the example illustrated in FIG. 1, the support lifters 30 are disposed at six locations. There is a risk that the workpiece W may vibrate to cause unstable behavior with just the lifters 20, and therefore the support lifters 30 cooperate with the lifters 20 to support the workpiece W from below. It is desirable that the support lifters 30 are provided in at least each one of the turning direction and the counter-turning direction of each lifter 20 with the lifter 20 interposed therebetween, in order to suppress unstable behavior of the workpiece W. The number of the support lifters 30 and the arrangement of the support lifters 30 can be appropriately changed according to a specific configuration of the workpiece W.

FIG. 3 is a perspective view of each support lifter 30. The support lifter 30 includes a cylinder body 31, a linear drive servomotor 32, and a sliding member 33. The support lifter 30 does not perform rotational operation like each lifter 20.

The cylinder body 31 is attached to the lower die 10, or the bolster or the like that supports the lower die 10, and is fixed so as not to move relative to the lower die 10.

The linear drive servomotor 32 is attached to the cylinder body 31, and is controlled by the control device 40 described later to cause a rod part 31a to advance and retreat.

The sliding member 33 is attached to a tip of the rod part 31a, and supports the workpiece without holding the workpiece W such that the workpiece can slide and move freely on the sliding member 33. The sliding member 33 can be made of, for example, urethane resin or the like.

FIG. 4 is a block diagram illustrating an outline of a control block of the die device 1. The control device 40 is connected to the lifters 20 and the support lifters 30. The control device 40 controls the drive of the lifters 20 by controlling the linear drive servomotors 24 of the lifters 20, the rotary drive servomotors 25, and vacuum pressure generating devices (not illustrated) connected to the vacuum cups 27. Further, the control device 40 controls the drive of the linear drive servomotors 32 of the support lifters 30.

FIG. 5 is a sectional view of the lower die 10 and the workpiece W cut at the position of the arrows A-A in FIG. 1. The arrow direction in FIG. 5 indicates the press direction. As illustrated in FIG. 5, the lower die 10 of this embodiment has an undercut region which is a portion that interferes with the workpiece when the workpiece W is moved along the press direction. The lower die 10 includes a movable die part 12 that moves in such a direction so as to release this undercut.

FIG. 6 is a diagram illustrating a state in which the movable die part 12 is moved in such a direction as to release the undercut. The movable die part 12 moves in the direction of the arrow in FIG. 6, so that a gap S can be provided between the movable die part 12 and the workpiece W, and the workpiece W can be moved upward in the press direction. FIG. 7 is a diagram illustrating a state in which the workpiece W is moved upward in the press direction. In order to move the workpiece W upward in the press direction, the lifters 20 and the support lifters 30 are controlled by the control device 40 to raise the workpiece W. The movable die part 12 retreats, so that the workpiece W can be moved upward in the press direction. However, when the workpiece W is raised in the press direction as it is, the workpiece W cannot be completely removed from the lower die 10 because a portion that remains as an undercut exists between the male die part 11 and the workpiece W.

Therefore, the control device 40 causes the lifters 20 to turn (swing) the workpiece W. At this time, the control device 40 also appropriately adjusts the heights of the support lifters 30, so that the workpiece W can slide and move on the sliding members 33 of the support lifters 30.

FIG. 8 is a diagram illustrating a state in which the workpiece W is turned. The alternate long and short dash line in FIG. 8 indicates a position where the workpiece W is present in the state of FIG. 7. The workpiece W is turned in the direction of the arrow in FIG. 8, so that the amount of interference at the undercut portion of the workpiece W is reduced.

Then, the control device 40 further extends the rod parts 23a of the lifters 20 from a position where the workpiece W is turned, and raises the workpiece W in the oblique direction at an angle with respect to the press direction.

FIG. 9 illustrates a state in which the workpiece W is raised in the oblique direction from the position where the workpiece W is turned. The alternate long and short dash line in FIG. 9 indicates a position where the workpiece W is present in the state of FIG. 8. The workpiece W is raised in the oblique direction from a position where the workpiece W is turned, so that the workpiece W can be completely released from the lower die 10 while avoiding interference due to the undercut. After that, the control device 40 causes the lifters 20 to rotate (swing) the workpiece W in the opposite direction, and further raise the workpiece W while returning the advancing/retreating direction of the rod part 23a to the press direction, so that the operation for releasing the workpiece W is terminated.

As described above, according to the first embodiment, the turnable lifters 20 are provided, and therefore the workpiece W can be appropriately released from the die even in a case where the undercut remains. Further, according to the configuration of this embodiment, the amount of retreat of the movable die can be reduced, and therefore a plurality of dies can be integrated to realize efficient forming.

Second Embodiment

FIG. 10 is a perspective view illustrating a lifter 20B of a second embodiment.

FIG. 11 is a sectional view illustrating the lifter 20B of the second embodiment. The second embodiment is different from the first embodiment only in that the lifters 20 in the first embodiment are replaced with the lifters 20B. Therefore, herein, only each lifter 20B will be described, and the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted. The lifter 20B of the second embodiment includes cam members 201, a support member 202, a central shaft 203, a cylinder body 204, a linear drive servomotor 205, and a vacuum cup 206.

The cam members 201 are attached to a lower die 10, or a bolster or the like that supports the lower die 10, and is fixed so as not to move relative to the lower die 10. Two cam members 201 are disposed so as to face each other. Further, the cam members 201 each have a cam groove 201a.

The support member 202 is fixed to a rod part 204a, described later, and can move integrally with the rod part 204a. Further, the support member 202 has pins 202a. These pins 202a are inserted into the cam grooves 201a, and function as turning drive parts that move along the cam grooves 201a by advancing and retreating movement of the rod part 204a to turn the lifters 20B. The support member 202 has through holes 202b, and the central shaft 203 described later penetrates the through holes 202b. The through holes 202b are opened sufficiently large such that the through holes 202b and the central shaft 203 do not come into contact with each other.

The central shaft 203 is fixed to the cylinder body 204, and is inserted into the cam members 201 in a rotatable state. Therefore, the cylinder body 204 described later can turn (swing) with respect to the cam members 201 about the central shaft 203.

As described above, the cylinder body 204 is attached to the cam members 201 so as to be tunable (swingable) about the central shaft 203. The rod part 204a advances and retreats upward from the cylinder body 204.

The linear drive servomotor 205 is attached to the cylinder body 204, and is controlled by the control device 40 to cause the rod part 204a to advance and retreat.

The vacuum cup 206 is attached to a tip of the rod part 204a. A specific configuration of the vacuum cup 206 of the second embodiment is the same as that of the vacuum cup 27 of the first embodiment.

FIGS. 12A to 12F are diagrams illustrating operation processes of the lifter 20B, the operation processes being arranged in order. The release operation of the workpiece W by the lifter 20B starts from the state illustrated in FIG. 12A, and is performed in the order of FIGS. 12B, 12C, . . . 12F. As illustrated in FIG. 12, as the rod part 204a extends from a state in which the protrusion amount of the rod part 204a is the shortest (FIG. 12A), the pins 202a move along the cam grooves 201a, and the cylinder body 204 and the rod part 204a gradually are inclined. Then, in the latter half, the rod part 204a further extends while returning the inclination of the cylinder body 204 and the rod part 204a, and operation for releasing the workpiece W is terminated (FIG. 12F).

As described above, according to the second embodiment, the same operation as that of the first embodiment can be performed without using another actuator such as the rotary drive servomotor 25 in the first embodiment. In the second embodiment, the linear drive servomotor is described as an example. However, a hydraulic drive cylinder such as an air cylinder may be used.

EXPLANATION OF REFERENCE NUMERALS

• 1 die device
• 10 lower die
• 11 male die part (fixed die part)
• 12 movable die part
• 20 lifter
• 20B lifter
• 21 base part
• 22 support member
• 23 cylinder body
• 23 a rod part
• 24 linear drive servomotor
• 25 rotary drive servomotor
• 26 speed reducer
• 27 vacuum cup (abutting part)
• 30 support lifter
• 31 cylinder body
• 31 a rod part
• 32 linear drive servomotor
• 33 sliding member
• 40 control device
• 201 cam member
• 201 a cam groove
• 202 support member
• 202 a pin
• 202 b through hole
• 203 central shaft
• 204 cylinder body
• 204 a rod part
• 205 linear drive servomotor
• 206 vacuum cup (abutting part)
• W workpiece

Claims

1. A die device comprising: a lower die; anda lifter that lifts a pressed workpiece from the lower die,the lower die having an undercut region which is a portion that interferes with the workpiece when the workpiece is moved along a press direction,the lifter comprising:an abutting part that comes into contact with the workpiece;a rod part having a distal end provided with the abutting part; anda driving means for causing the rod part to advance/retreat in an axial direction, andthe die device further comprising a turning drive part that turns the lifter in a direction orthogonal to the axial direction, whereinthe lifter moves the workpiece by combining both movement along the press direction and movement in a direction inclined to the press direction.

2. The die device according to claim 1, wherein the undercut region of the lower die includes:a movable die part that moves in such a direction as to release an undercut; anda fixed die part having a portion that remains as an undercut in relation with the workpiece even in a state in which the movable die part moves to perform release.

3. The die device according to claim 1, wherein the abutting part is provided with a vacuum cup.

4. The die device according to claim 1, further comprising support lifters that advance and retreat in a direction along the press direction,wherein the support lifters are provided in at least each one of a turning direction and a counter-turning direction of the lifter with the lifter interposed therebetween,the die device comprising a control device that controls protrusion positions of the support lifters in accordance with turning operation of the lifter.

5. The die device according to claim 4, wherein the support lifters are each provided with a sliding member for enhancing sliding performance between the workpiece and the support lifter, at a portion that comes into contact with the workpiece.

6. The die device according to claim 1, wherein the undercut region of the lower die includes:

7. The die device according to claim 1, wherein the undercut region of the lower die includes:a movable die part that moves in such a direction as to release an undercut; anda fixed die part having a portion that remains as an undercut in relation with the workpiece even in a state in which the movable die part moves to perform release,the die device further comprising support lifters that advance and retreat in a direction along the press direction,wherein the support lifters are provided in at least each one of a turning direction and a counter-turning direction of the lifter with the lifter interposed therebetween,the die device comprising a control device that controls protrusion positions of the support lifters in accordance with turning operation of the lifter.

8. The die device according to claim 1, wherein the undercut region of the lower die includes:a movable die part that moves in such a direction as to release an undercut; anda fixed die part having a portion that remains as an undercut in relation with the workpiece even in a state in which the movable die part moves to perform release,the abutting part is provided with a vacuum cup,the die device further comprising support lifters that advance and retreat in a direction along the press direction,wherein the support lifters are provided in at least each one of a turning direction and a counter-turning direction of the lifter with the lifter interposed therebetween,the die device comprising a control device that controls protrusion positions of the support lifters in accordance with turning operation of the lifter.

9. The die device according to claim 1, wherein the undercut region of the lower die includes:a movable die part that moves in such a direction as to release an undercut; anda fixed die part having a portion that remains as an undercut in relation with the workpiece even in a state in which the movable die part moves to perform release,the die device further comprising support lifters that advance and retreat in a direction along the press direction,wherein the support lifters are provided in at least each one of a turning direction and a counter-turning direction of the lifter with the lifter interposed therebetween,the die device comprising a control device that controls protrusion positions of the support lifters in accordance with turning operation of the lifter,wherein the support lifters are each provided with a sliding member for enhancing sliding performance between the workpiece and the support lifter, at a portion that comes into contact with the workpiece.

10. The die device according to claim 1, wherein the undercut region of the lower die includes:a movable die part that moves in such a direction as to release an undercut; anda fixed die part having a portion that remains as an undercut in relation with the workpiece even in a state in which the movable die part moves to perform release,the abutting part is provided with a vacuum cup,the die device further comprising support lifters that advance and retreat in a direction along the press direction,wherein the support lifters are provided in at least each one of a turning direction and a counter-turning direction of the lifter with the lifter interposed therebetween,the die device comprising a control device that controls protrusion positions of the support lifters in accordance with turning operation of the lifter, whereinthe support lifters are each provided with a sliding member for enhancing sliding performance between the workpiece and the support lifter, at a portion that comes into contact with the workpiece.