Die cushion device of pressing machine
AssigneeAida Engineering, Ltd.
InventorsYasuyuki Kohno, Katsunori Haseba, Junko Haseba
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Abstract
In a die-cushion device of a press machine a controller controls an opening degree of a proportional flow-rate control valve to an appropriate opening degree in order to control the flow rate flowing out of a lower chamber of a hydraulic cylinder supporting a cushion pad before a slide collides against the cushion pad using a die-cushion pressure command commanded from a commander in advance and a slide speed signal inputted from a slide speed detector. By this, generation of a surge pressure when a slide collides against the cushion pad at a high speed is restricted.
Claims46
A die-cushion device of a press machine comprising:
- a liquid-pressure cylinder which supports a cushion pad, the cushion pad configured to lower as a result of a collision with a slide of the press machine;
- a proportional flow-rate control valve provided in a flow passage connected to a lower chamber of the liquid-pressure cylinder;
- a die-cushion pressure command device which outputs a die-cushion pressure command set in advance;
- a slide speed detecting device which detects a slide speed of the press machine;
- and
- a control device which controls a flow rate discharged from the lower chamber of the liquid-pressure cylinder by controlling an opening degree of the proportional flow-rate control valve, wherein the control device controls the opening degree of the proportional flow-rate control valve before the cushion pad starts lowering so that the die-cushion pressure becomes a pressure corresponding to the die-cushion pressure command from the time of lowering of the cushion pad resulting from the collision, wherein the controlling of the opening degree is based on the die-cushion pressure command and the slide speed detected by the slide speed detecting device.
Dependencies are inferred from the claim text.