| 摘要 |
PURPOSE: To combine a proportion control area minimum discharge quantity control function during a no-load period and a pressure compensation control function during an over-load period, with a solenoid proportion control function. CONSTITUTION: A piston 22 is positioned when a spool 32 is displaced according to exciting current from a controller 15 and relative displacement between a valve body 33 and the spool 32 is converged at zero so that swash plate angle control having positional information feedback type positioning accuracy is executed. Proportion control area minimum discharge quantity control during a no-load period is executed by a no-load detecting switch 17 and the controller 15, and pressure compensation control during an over-load period is executed by a cutoff valve 51 and a switching valve 55. |
