DEVICE FOR CONTROLLING OIL PRESSURE TYPE CONSUMING MACHINE

摘要

A hydraulic control circuit for a cylinder-and-piston unit includes a relatively small electrohydraulically operated servo-control valve, a main pressure conduit including a measuring throttle, an auxiliary control valve cooperating with an additional pressure conduit connected parallel to the main pressure conduit to branch the pressure fluid in response to a predetermined level of pressure difference occurring across the measuring throttle. In this manner the servo-control valve can control a system of pressure fluid which is substantially larger than the nominal flow rate of the servo-control valve.