PILOT CONTROL VALVE FOR LOAD SENSING HYDRAULIC SYSTEM

摘要

A pilot control valve (35) is provided for use in a load sensing system including a priority flow control valve (21). The pilot valve includes a flow orifice (47) through which passes flow from the priority outlet port (23) to the motor (13). The pilot valve includes a valve sleeve (73) and a relatively rotatable valve spool (75). This valving controls fluid communication between the load signal port (49) and the system reservoir and main flow path, upstream and downstream of the flow orifice. Movement of the valve spool from a minimum flow position to a maximum flow position progressively varies the load signal (51) from reservoir pressure to system pressure, thus causing the output of the priority valve (21) to progressively increase from a minimum flow to a maximum flow.