JP2741688B2 - Work holding device in press machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for holding a work provided in a press machine, and more particularly to an apparatus for preventing a work from being displaced after release from a mold.

b. Prior Art For sheet metal processing of automobile parts and the like, for example, a press machine as shown in FIG. 3 is used. In the figure, 1
Is a lower mold, 2 is an upper mold, 3 is a blank holder, and 4 is a cushion pin. A plurality of blank lifters 5 are mounted on the blank holder 3 as shown in FIG.
It is arranged adjacent to. The lifter 5 has a hole 5a opened on the lower surface and a step 5b, as shown in detail in FIG. The spring 7 is placed in the hole 5a, and the lifter 5
Urges in a direction away from the blank holder 3. The lifter 5 is disposed in a concave portion 3a provided in the blank holder 3. Further, the blank holder 3 is provided with a stopper portion 8 for locking the step portion 5b of the blank lifter 5. Reference numeral 9 denotes a positioning gauge for a sheet (work) before molding, which is erected at a predetermined position on the blank holder 3 at an appropriate interval.

Now, when the upper mold 2 is raised after the work is formed, the blank lifter 5 is raised while pressing the work against the upper mold 2, and the stepped portion 5 b is brought into contact with the stopper portion 8 and locked. That is, the work can be lifted by the stroke 1 of the blank lifter 5.

By the way, when the work is taken out from the press machine by the automatic unloading device, it is necessary to hold the work at a predetermined position on the blank lifter 5. Therefore, as shown in FIG. 6, a pendulum-type lever 10 is pivotally attached to the holding portion 9a of the positioning gauge 9 to prevent the work from being displaced. The lever 10 has a weight portion 10a and a tip portion 10b.
In this apparatus, when the sheet A before molding is set on the die 6 of the lower mold 1, the lever 10 swings to the position shown by the two-dot chain line due to the weight of the weight 10a as shown in FIG. The tip 10b
A counterbore 11 is provided there to prevent the abutment against the blank holder 3.

c. Problems to be Solved by the Invention However, in the above device, a gap is formed between the edge of the work B and the lever 10, and the lever 10 is also configured to swing. B has a problem that when it receives a shock or vibration, it is greatly shifted from a predetermined position.

Further, since it is necessary to provide the counterbore 11 in the blank holder 3, the mold strength of the blank holder 3 is reduced, and a great deal of labor is required even when the mold is modified.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a work in a press machine that can completely prevent the work from being displaced after release and does not need to provide a counterbore in a blank holder. To provide a holding device.

d. Means for Solving the Problems The above objects are achieved by a lower die having a die, an upper die that moves up and down with respect to the lower die, and a blank holder that moves up with the upper die by a predetermined distance when the upper die moves upward. And a work holding device in a press machine having a blank lifter that is urged in a direction away from the blank holder and presses the work against the upper mold when the blank holder rises together with the upper mold. The movable stopper cam, the urging means for urging the stopper cam to rotate in one direction, and the urging direction of the urging means fixed to the upper die when the upper die descends. A holding member for rotating the stopper cam in the opposite direction is provided, and the shape of the stopper cam is held by the blank lifter when the upper die is raised. A part of the stopper cam comes into contact with the edge of the raised work, and when the upper die is lowered, the stopper cam is rotated by the pressing member, so that the upper die and the stopper cam do not collide with each other. The problem has been solved by a work holding device in a press machine characterized by the following.

e. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a stopper cam 20 is rotatably pivotally attached to a holding portion 9a of each of the positioning cages 9 by a shaft 20a. The cam 20 has a locking portion 21 provided on a peripheral surface thereof. . A connecting member 22 is fixed to the peripheral surface of the stopper cam 20, and a spring 23 is provided between the member 22 and the holding portion 9a of the positioning gauge 9. by this,
The stopper cam 20 is urged toward the die.
On the other hand, the upper die 2 is provided with an inverted L-shaped pressing member 25 for engaging with the locking portion 22 of the stopper cam 20. The other members are the same as those of the above-described conventional technology, and are denoted by the same reference numerals and description thereof will be omitted.

 Next, the operation of the present embodiment will be described.

Now, when the upper mold 2 is lowered toward the lower mold 1, the distal end portion 25 a of the pressing member 25 comes into contact with the locking portion 22 of the stopper cam 20 and rotates the cam 20 in a direction away from the die 6. The side of the tip 25a is the locking part 2 of the stopper cam 20.
Engage in a state of contact with the surface of 1. That is, the stopper cam 20 moves outside the positioning gauge 9 as shown in FIG. 1 to avoid collision with the upper die 2. After the forming of the work is completed, the upper die and the blank holder 3 rise while holding the flange portion of the work, and then only the blank holder 3 stops. Then, while the blank lifter 5 presses the work against the upper mold 2, the work is further raised and the stepped portion is formed.
When 5b comes into contact with the stopper portion 8, the blank lifter 5 also stops. That is, the work is a blank lifter 5
Is lifted from the blank holder 3 by the stroke l. Then, the stopper member 20 fixed to the upper die 2 is disengaged from the stopper cam 20, so that the stopper cam 20 constantly urged by the spring 23 rotates toward the die 6, and its arc-shaped edge 20b Will contact and hold the edge of the work B as shown in FIG.

f. Effects of the Invention According to the present invention, the work lifted by the blank lifter is held by the stopper cam, so that it is possible to completely prevent the work from being displaced after the mold release.

In addition, since it is not necessary to provide a counterbore in the blank holder, the strength of the blank holder can be prevented from lowering, and the time required for remodeling the mold can be reduced.

[Brief description of the drawings]

1 and 2 show an embodiment of the apparatus according to the present invention, FIG. 1 is a longitudinal sectional view of a positioning gauge portion, FIG. 2 is a view showing a state after the work release from FIG. 1, FIG. 3 is a cross-sectional view of the press machine taken along line BB, FIG. 4 is a plan view of the press machine with the upper die removed, FIG. 5 is a cross-sectional view taken along line AA of FIG. 6 and 7 are views showing a conventional example corresponding to FIGS. 1 and 2, respectively. 1 ... lower mold, 2 ... upper mold, 3 ... blank holder, 5
…… Blank lifter, 20 …… Stopper cam, 23 ……
Spring, 25 ... Pressing member.

Claims (1)

(57) [Claims] 1. A lower die 1 having a die 6, an upper die 2 which moves up and down with respect to the lower die 1, and a blank holder 3 which rises together with the upper die 2 by a predetermined distance when the upper die 2 moves upward. And a work holding device for a press machine having a blank lifter 5 which is urged in a direction away from the blank holder 3 and rises while pressing the work against the upper mold 2 when the blank holder 3 moves up together with the upper mold 2. A stopper cam 20 rotatable around a shaft 20a, an urging means for urging the stopper cam 20 to rotate in one direction, and fixed to the upper mold 2, when the upper mold 2 descends A pressing member for rotating the stopper cam in a direction opposite to the urging direction of the urging means; Some of the stopper cam 20 at the edge of the workpiece lifted by the coater 5 abuts the upper mold 2
A holding member for rotating the stopper cam by the pressing member, so that the upper die and the stopper cam do not collide with each other.