| 摘要 |
PURPOSE:To reduce reliably relief loss at a cheaper cost by restricting a pump when the relation between the operation speed of an actuator and a command signal shows the preliminary determined relation for the purpose of relief. CONSTITUTION:Actuators 61-6n are operated with a hydraulic pressure corresponding to the command signals depending on the operation angles of lever 11-1n. The output signals from the operation amount detectors 81-8n attached to each said actuator 61-6n are differentiated with a differential device 71-7n and thus obtained operation speed are inputted to CPU together with the above mentioned command signals. In a memory circuit 10, the relation between each speed of the actuators during relief and the command signals, i.e. the displacement of said lever is stored. For example, when the actuator 61 is maintained in a relief state, the CPU in which the speed (V) and the output signal of the lever 11 are inputted compares them with the data of the memory circuit 10, detects the relief state and then, for example, controls the actuator so as to restrict the cam plate of the hydraulic pump to 50%. |
