Abstract: A control valve device includes a valve body having an actuator port connected to an actuator and a relief passage configured to allow the actuator port to communicate with a return passage, a spool slidably assembled into the valve body and configured to allow the actuator port to selectively communicate with a supply side or a return side, a relief valve configured to open/close the relief passage to control pressure of the actuator port, and an on/off valve assembled into an assembling hole which is formed in the valve body. The on/off valve configured to allow the actuator port to communicate with the relief passage through the assembling hole at the time of valve open.

Abstract: A valve structure includes a switching valve; and a compensator valve configured to maintain a flow dividing ratio determined by a switching amount of the switching valve to be constant irrespective of a load change of an actuator connected to the switching valve. An axis line of a main spool provided in the switching valve and an axis line of a compensator spool provided in the compensator valve are parallel to each other.

Abstract: A control valve device includes a valve body having an actuator port connected to an actuator and a relief passage configured to allow the actuator port to communicate with a return passage, a spool slidably assembled into the valve body and configured to allow the actuator port to selectively communicate with a supply side or a return side, a relief valve configured to open/close the relief passage to control pressure of the actuator port, and an on/off valve assembled into an assembling hole which is formed in the valve body. The on/off valve configured to allow the actuator port to communicate with the relief passage through the assembling hole at the time of valve open.