Servo hydraulic press
AssigneeAutomation, Press and Tooling, AP & T AB
InventorsMikael Karlsson, Thomas Carlsson
Life of this patent
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Abstract
The present invention relates to a servo hydraulic press for sheet metal forming. The press comprises a hydraulic cylinder, at least two servo motors and at least two pumps for supplying pressurized fluid to the hydraulic cylinder, where each servo motor drives at least one pump. The servo motors are operable at variable speed, and the first servo motor and first pump are operable in an opposite direction to the second servo motor and the second pump. With this arrangement, the servo hydraulic press may be operated at low speed without causing damage to the pumps or motors.
Claims11
A servo hydraulic press for sheet metal forming comprising:
- a hydraulic cylinder;
- a first servo motor and a second servo motor;
- a first pump and a second pump for supplying pressurized fluid to the hydraulic cylinder,
- wherein the first servo motor drives the first pump, and the second servo motor drives the second pump, and
- wherein the servo motors are operable at variable speed, and
- the first pump and the second pump together provide a total flow of pressurized fluid in a closed loop supply to an upper chamber of the hydraulic cylinder;
- and
- a controller configured to operate the first servo motor and the first pump to flow pressurized fluid in an opposite direction to the flow of pressured fluid from the second servo motor and the second pump such that a reduced total flow of pressurized fluid to the upper chamber of the hydraulic cylinder is provided by the first pump and the second pump.
A method for controlling a hydraulic cylinder in a servo hydraulic press for forming sheet metal, the method comprising the steps of
- supplying pressurized fluid in a closed loop supply to an upper chamber of the hydraulic cylinder comprising a first servo motor that drives a first pump and a second servo motor that drives a second pump,
- operating the servo motors at variable speed, and
- operating the flow of pressured fluid of the first servo motor and the first pump in an opposite direction to the flow of pressurized fluid from the second servo motor and the second pump such that a reduced total flow of pressurized fluid to the upper chamber of the hydraulic cylinder is provided together by the first pump and the second pump.
Dependencies are inferred from the claim text.