Patent ID: 8505581

Claim:
A pressure compensated electromagnetic proportional directional flow control valve integrally comprising: an electromagnetic proportional directional flow control valve configured to be driven by a solenoid; and a pressure compensated valve configured to carry out pressure compensation of a flow rate controlled by the electromagnetic proportional directional flow control valve, wherein: the electromagnetic proportional directional flow control valve includes: an introducing port to which a liquid is introduced from the pressure compensated valve; first and second external connection ports which are communicated with an external liquid-pressure actuator; a return port which is communicated with a tank; a directional flow control spool configured to control passages extending among the above ports; a first variable aperture which is formed on the passage extending between the introducing port and the first external connection port by movement of the directional flow control spool; and the pressure compensated valve includes: a liquid-pressure supply port which is communicated with an external liquid-pressure source; a derivation port through which a liquid from the liquid-pressure supply port is introduced to the introducing port; a branch port through which a surplus liquid of the liquid flowing from the liquid-pressure supply port to the derivation port flows out to outside; a pressure compensation spool configured to control passages extending among the above ports; a spring configured to bias the pressure compensation spool in a bias direction; a first pressure chamber configured to bias the pressure compensation spool in a direction opposite the bias direction of the spring; a second pressure chamber configured to bias the pressure compensation spool in a direction that is the same as the bias direction of the spring; a first pressure passage through which pressure existing upstream of the first variable aperture is introduced to the first pressure chamber; and a second pressure passage through which pressure existing downstream of the first variable aperture is introduced to the second pressure chamber; and wherein the first pressure passage is also communicated with the second pressure chamber wherein the first pressure passage is formed in the pressure compensation spool.