JPH07100552A - Die cushion device of press - Google Patents

Abstract

PURPOSE:To control the cushion force at a plurality of independent points. CONSTITUTION:In a die cushion device of a press where a pad body 1 is elastically supported by a cushion cylinder 6, and the cushion force is controlled by an NC-controlled NC cushion cylinder 7, the pad body 1 is segmented into a plurality pieces, and a part thereof is connected by a connecting means 2 to form a flexible structure, and at least one cushion cylinder 6 and one NC cushion cylinder 7 are provided for the respective pad members 1a, 1b. The cushion force can be controlled at a plurality of independent points by realizing the NC control of each NC cushion cylinder 7, leading to the highly precise press forming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die cushion device for a press using a flexible pad.

[0002]

2. Description of the Related Art As a die cushion device for a conventional press, for example, Japanese Patent Laid-Open Nos. 61-14026 and 63-63.
-63533, JP 60-176823, JP 61-186923, JP 1958.
Various structures are known in Japanese Patent Publication No. 17 and the like.

[0003]

However, since all of the conventional die cushion devices use a pad having a high rigidity and an integral structure, the cushion force is almost evenly applied to the mold elastically supported through the pad. There was a problem that it acted and it was not possible to adjust the cushioning force partially.

German patent specification 324270
No. 5 discloses a die cushion device in which the pad is divided into a plurality of parts so that the cushioning force can be adjusted for each pad. However, when the pads are divided into multiple pads, the parallelism between the pads decreases due to the gap between the liners provided between the pads, and the inclination of each pad becomes larger than that of a large pad, so Cushion pins arranged at eccentric positions may not come into contact with the pads, which causes a problem such as variations in pin pressing force. The present invention has been made to solve such a problem, and an object of the present invention is to provide a press die cushion device capable of controlling cushioning force at plural independent points by using a pad having a flexible structure. To do.

[0005]

In order to achieve the above object, the present invention elastically supports a pad body by a cushion cylinder and controls the cushion force by NC.
In a die cushion device of a press controlled by a C cushion cylinder, the pad body is divided into a plurality of parts, and a part of them is connected by a connecting means to form a flexible structure,
Further, at least one cushion cylinder and NC cushion cylinder are provided for each pad member.

[0006]

[Operation] With the above configuration, by controlling each NC cushion cylinder by NC, the cushion force can be independently controlled at a plurality of points, which enables press molding with higher accuracy.

[0007]

Embodiment An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. In these figures, 1 is a box-shaped pad main body, and a pad member 1a,
It is divided into two parts 1b. Each pad member 1a, 1b
A mating surface 1c is formed on the lower part of the divided surface of the pad, and the connecting parts 1d, 1 are provided on the lower part of the pad members 1a, 1b.
The pad members 1a and 1b are connected to each other through the mating surface 1c by fastening the connecting parts 2e by means of bolts or the like, and at the same time, each pad 1 is attached to the mating surface 1c.
A key 3 is interposed to prevent the a and 1b from being displaced in the vertical direction.

A liner 4 is laid vertically on the dividing surface of each pad member 1a, 1b with a gap.

On the other hand, a cushion cylinder 6 made of an air cylinder is provided below the center of each pad member 1a, 1b.
Also, NCs composed of hydraulic cylinders are provided at the four corners of the pad body 1.
A cushion cylinder 7 is provided. The cushion cylinder 6 is fixed to a bed 8 of the press, and the center of each pad member 1a, 1b is connected from below to the tip of a piston rod 6a protruding upward from the cushion cylinder 6.

Further, the tip end of the piston rod 7a protruding upward from the NC cushion cylinder 7 is connected to the four corners of the pad body 1 from below, and the NC cushion cylinder 7 is connected to an NC device (not shown). Each NC
The cushion force can be controlled independently for each cushion cylinder 7.

The operation will be described below. A mold installed in a press (not shown) is supported on the upper surface of the pad body 1 through a plurality of cushion pins (none of which are shown).
When the molding is started, the pad body 1 is lowered and the cushion cylinder 6 can obtain a cushioning action. Further, in order to obtain a substantially uniform cushioning force for the entire mold, the flow rates of the four NC cushion cylinders 7 should be controlled in the same manner. Control the pressure for each.

The pad body 1 is divided into a plurality of parts in advance, and some of them are connected by a connecting means 2.
Since the movement between a and 1b is restricted by the connecting means 2, the cushioning force can be independently controlled at four points of the pad body 1.

In the above embodiment, the lower part of the divided surface of the divided pad members 1a and 1b is connected by the connecting means 2. However, as shown in FIG. The pad members 1a and 1b may be allowed to move relative to each other with the connecting means 2 as a center. Although the pad body 1 is divided into two in the above embodiment, it may be divided into three or more, and the cushion cylinder 6 and the NC cushion cylinder 7 may be added in accordance with the number of divisions. Further, although the cushion cylinder 6 and the NC cushion cylinder 7 are separate bodies in the above-described embodiment, the NC cushion cylinder 7 may be provided below or above the cushion cylinder 6.

[0014]

As described above in detail, the present invention makes it possible to independently control the cushioning force at a plurality of points by making the pad body a flexible structure and controlling the NC cushion cylinders provided at a plurality of locations by NC control. Therefore, the cushioning force can be partially controlled according to the shape of the molded product. This enables press molding with high accuracy, and since the pad body has a flexible structure, the pad member does not have a large inclination unlike a multi-divided pad, and the pressure applied to the cushion pin varies. Problems such as occurrence of can be solved.

[Brief description of drawings]

FIG. 1 is a plan view showing a die cushion device of a press according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a sectional view showing a pad of a die cushion device according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Pad main body, 1a, 1b ... Pad member, 2 ... Connection means, 6 ... Cushion cylinder, 7 ... NC cushion cylinder.

Claims (1)

[Claims] 1. A die cushion device for a press, wherein the pad body 1 is elastically supported by a cushion cylinder 6 and the cushion force is controlled by an NC cushion cylinder 7 which is NC controlled. A die cushion device for a press, in which at least one cushion cylinder 6 and NC cushion cylinder 7 are provided for each pad member 1a, 1b to form a flexible structure by connecting a part of them with a connecting means 2.