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US 12,172,403 B2Granted
Die cushion device
AssigneeAida Engineering, Ltd.
InventorTadahiro Kondo
Life of this patent
Estimating the term…
Abstract
The die cushion device includes a first hydraulic cylinder for supporting a cushion pad, and a first hydraulic circuit for driving the first hydraulic cylinder. The first hydraulic circuit is a hydraulic closed circuit including a logic valve connected between a die cushion pressure generation line and a system pressure line, and a hydraulic pump driven by a first servomotor for applying a pilot pressure to the logic valve. The first controller controls the first servomotor (pilot pressure) based on a first pressure command corresponding to the die cushion force and the pressure detected by the first pressure detector to control the pressure in a lower chamber of the first hydraulic cylinder so that the pressure is equal to a pressure corresponding to the first pressure command.
Claims27
A die cushion device comprising:
- a first hydraulic cylinder configured to support a cushion pad and cause the cushion pad to generate a die cushion force in a case where a slide of a press machine is moved downward;
- a first hydraulic circuit configured to drive the first hydraulic cylinder;
- a first pressure commander configured to output a first pressure command indicating a die cushion pressure corresponding to the die cushion force;
- a first pressure detector configured to detect a pressure in a lower chamber of the first hydraulic cylinder;
- and
- a first controller configured to control the first hydraulic circuit based on the first pressure command and the pressure detected by the first pressure detector in such a manner that a pressure applied to the lower chamber of the first hydraulic cylinder is equal to a pressure corresponding to the first pressure command,
- wherein the first hydraulic circuit is a hydraulic closed circuit including a die cushion pressure generation line connected to the lower chamber of the first hydraulic cylinder, a system pressure line to which a first accumulator configured to accumulate hydraulic fluid having a first system pressure is connected, a pilot-operated logic valve which has an A port connected to the die cushion pressure generation line and a B port connected to the system pressure line, and a pressure generator configured to generate a pilot pressure to act on a pilot port of the logic valve,
- wherein the first controller controls the pilot pressure based on the first pressure command and the pressure detected by the first pressure detector, and controls a pressure of hydraulic fluid flowing from the A port of the logic valve to the B port of the logic valve in such a manner that a pressure of hydraulic fluid in the lower chamber of the first hydraulic cylinder which is a pressure on the A port side is equal to the pressure corresponding to the first pressure command,
- wherein the first hydraulic circuit includes a first hydraulic line configured to connect the pressure generator and the die cushion pressure generation line, and a second hydraulic line configured to connect an upper chamber of the first hydraulic cylinder and the system pressure line,
- the first pressure commander outputs a second pressure command for pre-pressurizing the lower chamber of the first hydraulic cylinder to have a preset pressure before press forming, and
- the first controller controls the pressure generator based on the second pressure command and the pressure detected by the first pressure detector to pre-pressurize the lower chamber of the first hydraulic cylinder to have a pressure corresponding to the second pressure command before press forming.
8 more elements
A die cushion device comprising:
- a first hydraulic cylinder configured to support a cushion pad and cause the cushion pad to generate a die cushion force in a case where a slide of a press machine is moved downward;
- a first hydraulic circuit configured to drive the first hydraulic cylinder;
- a first pressure commander configured to output a first pressure command indicating a die cushion pressure corresponding to the die cushion force;
- a first pressure detector configured to detect a pressure in a lower chamber of the first hydraulic cylinder;
- and
- a first controller configured to control the first hydraulic circuit based on the first pressure command and the pressure detected by the first pressure detector in such a manner that a pressure applied to the lower chamber of the first hydraulic cylinder is equal to a pressure corresponding to the first pressure command,
- wherein the first hydraulic circuit is a hydraulic closed circuit including a die cushion pressure generation line connected to the lower chamber of the first hydraulic cylinder, a system pressure line to which a first accumulator configured to accumulate hydraulic fluid having a first system pressure is connected, a pilot-operated logic valve which has an A port connected to the die cushion pressure generation line and a B port connected to the system pressure line, and a pressure generator configured to generate a pilot pressure to act on a pilot port of the logic valve,
- wherein the first controller controls the pilot pressure based on the first pressure command and the pressure detected by the first pressure detector, and controls a pressure of hydraulic fluid flowing from the A port of the logic valve to the B port of the logic valve in such a manner that a pressure of hydraulic fluid in the lower chamber of the first hydraulic cylinder which is a pressure on the A port side is equal to the pressure corresponding to the first pressure command,
- wherein the pressure generator comprises a hydraulic pump arranged between the system pressure line and the pilot port of the logic valve, and a first servomotor connected to a rotating shaft of the hydraulic pump, and
- during press forming, the first controller controls a torque of the first servomotor based on the first pressure command and the pressure detected by the first pressure detector to control the pilot pressure.
7 more elements
A die cushion device comprising:
- a first hydraulic cylinder configured to support a cushion pad and cause the cushion pad to generate a die cushion force in a case where a slide of a press machine is moved downward;
- a first hydraulic circuit configured to drive the first hydraulic cylinder;
- a first pressure commander configured to output a first pressure command indicating a die cushion pressure corresponding to the die cushion force;
- a first pressure detector configured to detect a pressure in a lower chamber of the first hydraulic cylinder;
- and
- a first controller configured to control the first hydraulic circuit based on the first pressure command and the pressure detected by the first pressure detector in such a manner that a pressure applied to the lower chamber of the first hydraulic cylinder is equal to a pressure corresponding to the first pressure command,
- wherein the first hydraulic circuit is a hydraulic closed circuit including a die cushion pressure generation line connected to the lower chamber of the first hydraulic cylinder, a system pressure line to which a first accumulator configured to accumulate hydraulic fluid having a first system pressure is connected, a pilot-operated logic valve which has an A port connected to the die cushion pressure generation line and a B port connected to the system pressure line, and a pressure generator configured to generate a pilot pressure to act on a pilot port of the logic valve,
- wherein the first controller controls the pilot pressure based on the first pressure command and the pressure detected by the first pressure detector, and controls a pressure of hydraulic fluid flowing from the A port of the logic valve to the B port of the logic valve in such a manner that a pressure of hydraulic fluid in the lower chamber of the first hydraulic cylinder which is a pressure on the A port side is equal to the pressure corresponding to the first pressure command,
- wherein the die cushion device further comprising:
- a second hydraulic cylinder configured to support and move the cushion pad in an up and down direction;
- a second hydraulic circuit configured to drive the second hydraulic cylinder;
- a die cushion position commander configured to output a die cushion position command indicating a position of the cushion pad;
- a die cushion position detector configured to detect the position of the cushion pad;
- and
- a second controller configured to control the second hydraulic circuit based on the die cushion position command output from the die cushion position commander and the position of the cushion pad detected by the die cushion position detector in such a manner that the position of the cushion pad matches a position corresponding to the die cushion position command.
12 more elements
A die cushion device comprising:
- a first hydraulic cylinder configured to support a cushion pad and cause the cushion pad to generate a die cushion force in a case where a slide of a press machine is moved downward;
- a first hydraulic circuit configured to drive the first hydraulic cylinder;
- a second hydraulic cylinder configured to support the cushion pad and move the cushion pad in an up and down direction;
- a second hydraulic circuit configured to drive the second hydraulic cylinder;
- a die cushion position commander configured to output a die cushion position command indicating a position of the cushion pad;
- a die cushion position detector configured to detect a position of the cushion pad;
- and
- a second controller configured to control the second hydraulic circuit based on the die cushion position command output from the die cushion position commander and the position of the cushion pad detected by the die cushion position detector in such a manner that the position of the cushion pad matches a position corresponding to the die cushion position command,
- wherein the first hydraulic circuit is a hydraulic closed circuit including a die cushion pressure generation line connected to a lower chamber of the first hydraulic cylinder, a system pressure line to which a first accumulator for accumulating hydraulic fluid having a first system pressure is connected, a pilot-operated logic valve which has an A port connected to the die cushion pressure generation line and a B port connected to the system pressure line, and a pilot pressure applying unit configured to apply a pilot pressure to act on a pilot port of the logic valve.
6 more elements
Dependencies are inferred from the claim text.