To avoid collision of a piston to its end of stroke.
A hydraulic cylinder operation control device is arranged so that a movable element 105 is moved under control inside a hydraulic motor 110 and includes a lever device 125 to generate an operator command signal which indicates the desired speed and moving direction for the movable element 105. A position sensor 130 senses the position of the movable element 105 and emits a position signal. An electronic controller 140 receives the operator command signal and the position signal, determines the actual speed of the element 105, and determines the limit value in compliance with the obtained actual speed of the element 105. In addition, the controller compares the size of the operator command signal with the limit value and emits a flow control signal in accordance with the result from comparison. An electronic hydraulic controller 145 receives a flow control signal to control the motion of the element 105 accordingly.
DUFFY JOHN D
KOOFURAA DOUGLAS W
| JPH06146328A | 1994-05-27 | |||
| JPH05196004A | 1993-08-06 | |||
| JPH11117346A | 1999-04-27 | |||
| JPH0771405A | 1995-03-17 |