Hydraulic system for hydraulically-operated machine e.g. excavator, has recovery control valve which regulates flow of pressurized fluid from head chamber of second boom cylinder to accumulator

摘要

A control valve assembly (40) includes a first workport (46) connected to a node (51), and a second workport (48)connected to the rod chamber (33,36) of first and second boom cylinders (31,32). Each workport is selectively connected to a supply conduit (25) and a return conduit (26) when the control valve assembly is operated. A bidirectional electrohydraulic proportional (EHP) recovery control valve (62) regulates the flow of pressurized fluid from the head chamber (38) of the second boom cylinder to an accumulator (60).