| 摘要 |
<p>PURPOSE:To make it possible to smoothly operate an actuator, by disposing a shut-off valve which is subjected to duty ratio control, between a direction selector valve for the actuator and a fluid pressure source. CONSTITUTION:A pump P is connected to cylinder chambers 56, 57 in a shift actuator 51 in a speed change gear actuator 5, through direction selector valves V7, V8, respectively. A shut-off valve V1 subjected to duty ratio control is disposed between the direction selector valves V7, V8 and the pump P. Accordingly, when a control device controls duty ratio control so that the shut-off valve V1 is intermittently opened and closed, the fluid pressure in the cylindrical chambers 56, 57 in the shift actuator 51 may be gradually raised, thereby it is possible to make the operation of the actuator smooth.</p> |
