JP7403794B2 - Double acting press mold - Google Patents

Description

The present invention relates to a double-acting press mold that can be used for deep drawing and that can be mounted on a compact press machine.

A press device is used to form the metal sheet. Press equipment is also used in drawing, which involves forming a cylindrical shape from a metal plate.As the drawing depth increases, a lower bolster and an upper slide are used to take out the workpiece after drawing. Since the distance between the presses and the presses had to be long, a larger press device was required.

For example, Patent Document 1 discloses a vertically double-acting hydraulic press device for deep drawing, which performs deep drawing by lowering an upper ram slide on which a die is attached and raising a lower punch. It shows you how to do it. This device requires hydraulic devices at the top and bottom, which poses a problem in that the press device is large and expensive.

Further, Patent Document 2 discloses a method for forming opposing hydraulic pressure in a container. In this method, a cylindrical container is formed by lowering a punch from above into a water chamber located at the bottom of the device. In the case of this method, a dedicated press device having a water chamber is required, so there is a problem in that production flexibility is lacking.

Japanese Unexamined Patent Publication No. 52-106175 Japanese Patent Application Publication No. 8-150420

In view of the above-mentioned problems, the present invention provides a double-acting press mold that can reduce the distance between the upper and lower molds by separately driving punches within the mold, and that can be installed on existing press equipment. The task is to

In order to solve the above problems, a double-acting press die according to the present invention is a deep drawing die in which a blank is arranged between an upper die and a lower die and the blank is formed into a cylindrical shape. It is housed in a mold and is configured to protrude only when drawing is performed.

It is preferable that the drawing punch part does not protrude from at least an outer surface of the blank holder when the drawing punch part is housed in the mold. It is also preferable that, when the mold is attached to a press machine, the drawing punch is configured to protrude from the mold near the bottom dead center of the press operation.

In the double-acting press mold according to the present invention, the punch is housed in the mold and is projected from the blank holder to perform drawing when necessary, so that the distance between the upper and lower molds can be shortened. Furthermore, since it is a mold, it can be attached to an existing press device, and deep drawing can be performed with a compact press device.

Hereinafter, preferred embodiments of the present invention will be described based on Examples. FIG. 1 shows an embodiment of a double-acting press mold according to the present invention. This figure shows a state in which a mold set consisting of an upper mold 11 and a lower mold 21 is mounted on the press main body 1. The upper mold 11 is fixed to the slide 2 of the press machine 1, and a punch 13 is disposed in a housed state. This punch 13 is configured to be movable up and down relative to the upper mold 11 by a punch actuator 12. Further, a blank holder 15 is arranged on the lower surface side of the upper mold 11 at a certain distance A, excluding the movable range of the punch 13, and is configured to be movable up and down within a certain range by a blank holder shock absorber 14. ing. On the other hand, the lower die 21 is fixed to the bolster 3 of the press machine 1, and has a hole formed therein for deep drawing. A knockout plate 22 is disposed within this hole, and is configured to be movable up and down by a knockout device 23.

Next, the operation of the double-acting press die according to the present invention will be explained. FIG. 3 shows a series of operation explanatory diagrams of an embodiment of the present invention as sectional views of main parts. (1) shows the state before operation. The punch 13 is housed in the upper mold 11 and is arranged so that the tip of the punch 13 is located on substantially the same surface as the lower surface of the blank holder 15. Further, a blank 31 is placed on the lower mold 21. (2) shows the initial state of the deep drawing operation. The upper mold 11 descends to the surface of the blank 31, and the blank holder 15 holds the blank 31. In (3) , with the blank holder 15 holding the blank 31, only the punch 13 is further lowered to perform deep drawing. (4) shows the state after deep drawing is completed, the punch 13 is housed in the upper mold 11, the upper mold 11 rises, and the knockout plate pushes up the molded product 32 onto the mold 21. In the above-mentioned operation, the punch actuator operates after the blank holder holds the blank, and at that stage the press reaches near the bottom dead center and moves slowly. By driving the punch at this stage, more uniform aperture can be achieved.

A comparison between the double acting press mold according to the present invention and a conventional mold will be described. In deep drawing, as can be seen from (4) in FIG. 3, in order to take out the molded product, a distance longer than the deep drawing length is required between the upper die (or blank holder) and the lower die. A cross-sectional view of a conventional mold is shown in FIG. In this mold, since the punch 13 is fixed on the upper mold 11, the length of the upper mold 11 becomes long. Also, the press stroke is distance A (punch length) + distance B (distance between dies). Therefore, C (deep drawing length) is less than half of A+B, and is generally about one-third. On the other hand, in the mold according to the present invention shown in FIG. 1, the distance A can be made as small as possible because the punch 13 is housed within the mold. Therefore, when the mold is mounted on a press machine with the same distance between the slide and the bolster, the mold according to the present invention allows deeper drawing. Alternatively, when drawing to the same depth, the mold of the present invention allows the drawing to be performed using a more compact press machine.

As described above, in the double-acting press die according to the present invention, deeper drawing is possible by storing the punch in the upper die and driving it only when necessary, or when drawing to the same depth. It becomes possible to use a more compact press machine. Further, since the mold according to the present invention can be attached to an existing press machine, there is no need to use a press machine with a long stroke to perform deep drawing. Thus, it is very useful in deep drawing press molding.

1 is a side sectional view showing an embodiment of a double-acting press die according to the present invention. FIG. 2 is a side sectional view showing a conventional press mold. FIG. 3 is an explanatory diagram showing the operating state of the double-acting press die of the present invention.

1: Press main body 2: Slider 3: Bolster 11: Upper die 12: Punch actuator 13: Punch 14: Blank holder shock absorber 15: Blank holder 21: Lower die 22: Knockout plate 23: Knockout device 31: Blank 32: Molding later products

Claims (1)

In a deep drawing die in which a blank is arranged between an upper die and a lower die and the blank is formed into a cylindrical shape, the drawing punch portion is housed in the upper die so as not to protrude from at least an outer surface of the blank holder. 1. A double -acting press die, characterized in that the die is driven by a punch actuator separate from the press operation, and is configured to protrude from the upper die near the bottom dead center of the press operation .

Images