Die cushion apparatus of press machine and die cushion controlling method

Patent metadata

Field	Value
Publication number	US-10363594-B2
Application number	US-201615368315-A
Country	US
Kind code	B2
Filing date	Dec 2, 2016
Priority date	Jan 24, 2013
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

According to the die cushion apparatus of a press machine and the die cushion controlling method of the present invention, in holding the cushion pad on standby at a desired standby position, it is possible to hold the cushion pad on standby in parallel with the lower faces of the dies mounted to the slide, and if the lower faces of the dies are inclined, it is possible to hold the cushion pad on standby in the state of being inclined. Through this configuration, it is possible to easily allow the material to come into contact with the lower faces of the dies from the beginning of the die cushion force control (beginning of the collision), and also possible to smoothen the die cushion action in the plane, thereby enhancing the formability.

First claim

What is claimed is:

1. A die cushion apparatus of a press machine, the press machine including an upper die mounted to a slide, a lower die mounted to a bed, and a blank holding plate disposed between the upper die and the lower die and mounted to a cushion pad, the die cushion apparatus comprising:
multiple cushion pad raising and lowering devices configured to raise and lower the cushion pad by separately-controllable multiple driving shafts;
a die cushion position instructing unit configured to output position instruction values for instructing positions of the multiple cushion pad raising and lowering devices in a raising and lowering direction, the position instruction values including standby position instruction values for at least holding the cushion pad at a standby position, and outputting the standby position instruction values after knocking out a product from the press machine;
multiple die cushion position detecting devices configured to detect the position of the cushion pad corresponding to the position for each driving shaft of the multiple cushion pad raising and lowering devices, and output position detection values indicating the detected positions;
an information acquiring device configured to acquire information regarding inclination of the cushion pad based on the position detection values outputted from the multiple die cushion position detecting devices in a duration of a die cushion force control of the press machine;
an offset adjusting device configured to offset the position instruction values including the standby position instruction values outputted from the die cushion position instructing unit based on the multiple position detection values outputted from the multiple die cushion position detecting devices to affect the acquired inclination of the cushion pad at the standby position; and
a controlling device configured to separately control the multiple cushion pad raising and lowering devices based on the position instruction values outputted from the die cushion position instructing unit, and on the multiple position detection values outputted from the multiple die cushion position detecting devices, the controlling device configured to move the cushion pad to the standby position based on the offset standby position instruction values outputted from the die cushion position instructing unit after knocking out the product,
wherein the offset adjusting device offsets the standby position values based on the information regarding inclination of the cushion pad acquired from the information acquiring device to allow the cushion pad to be inclined in the standby position to be parallel with lower faces of the upper die mounted to the slide of the press machine.

2. The die cushion apparatus of a press machine according to claim 1 , further comprising a correcting device configured to, based on the information regarding inclination of the cushion pad acquired from the information acquiring device, automatically correct the offset standby position instruction values set in the offset adjusting device so as to hold the inclination of the cushion pad at the standby position of the cushion pad.

3. The die cushion apparatus of a press machine according to claim 1 , wherein the information acquiring device acquires the multiple position detected values outputted from the multiple die cushion position detecting devices as the information regarding the inclination of the cushion pad, wherein the multiple position detected values are associated with each time in the duration of the die cushion force control, a position of the slide, or die cushion force applied onto the multiple driving shafts.

4. The die cushion apparatus of a press machine according to claim 1 , wherein the multiple cushion pad raising and lowering devices function as cushion force generating devices that generate a die cushion force via the multiple driving shafts at a time of lowering the slide of the press machine.

Assignees

• Aida Eng Ltd

Inventors

• Kohno Yasuyuki
• Kondo Tadahiro
• Iwamura Ryosho

Classifications

• B21D24/08

  Pneumatically or hydraulically loaded blank holders · CPC title

• B21D24/14 Primary

  pneumatically or hydraulically · CPC title

• B21D24/02 Primary

  Die-cushions · CPC title

• B30B15/24

  controlling the movement of a plurality of actuating members to maintain parallel movement of the platen or press beam · CPC title

• B21D22/22

  with devices for holding the edge of the blanks (B21D22/24 - B21D22/30 take precedence; shaping over a die without external former B21D11/02) · CPC title