DIRECTIONAL CONTROL VALVE WITH FLOW DIVIDING VALVE

摘要

Simplification of the casing structure of a directional control valve provided with a backward installation type flow dividing valve and the valve is achieved as follows. A pair of flow dividing valves (8) and hold check valves (9) are arranged between a pair of metering notches (6) having both functions of flow rate and directional control, formed in the land (4-1) of a spool (2), and a pair of actuator ports A, B. Respective hold check valves are provided with hollow spool-form valve discs (90) in which a seat (12) is formed at the outer periphery and the pressure of the outlet passage (10) connected to the actuator port acts in the closing direction of the valve. Respective flow dividing valves are provided with valve discs (80) fitted in these valve discs (90) so as to freely slide, facing the inlet passage (7) connected to the metering notch at the front face and facing the control pressure chamber (30) connected to a signal detection oil passage at the back face. The valve disc (90) is shaped to balance the pressure of the control pressure chamber. A slit (21) of a variable dead zone X2 is formed between the valve discs (80, 90) and the pressure between the outlet of the flow dividing valve and the inlet of the hold check valve is detected to transmit it to the control pressure chamber.