Proportional flow divider valve

摘要

A proportional flow divider valve is configured only as a controlled flow valve by using a first spool in a valve body or as both a free flow valve as well as control flow valve by using a second spool in the valve body. The second spool is provided with a return fluid check valve which is integral therewith and disables the control flow mode when pressure is applied to a piston surface on the return flow check valve. The return flow check valve is configured as a split sleeve which fits around a lateral inlet passage through the second spool and is urged to close the lateral inlet passage under pressure from returning hydraulic fluid. Normally, the split sleeve is axially biased by a vented coil spring to open the lateral inlet passage in the spool. When the lateral inlet passage is closed, it blocks the return of hydraulic fluid entering work ports in the valve body from flowing through metered end arrangements of the spool and allows the fluid to flow into a central annular chamber disposed around the spool and then out of an inlet port in the valve body.