Pilot operated directional control valve having position detecting function

摘要

The present invention provides a simply constructed pilot operated directional control valve having a position detecting function which is capable of detecting operating positions of a valve member such as a spool 6 by utilising a light sensor. To achieve this, an object to be detected 21 is formed on an end face of a piston 12a adjacent to a breathing chamber 9. A recess 22 in which the object to be detected 21 fits is disposed in the wall surface of the breathing chamber 9 in a casing 4. An optical sensor 25 is mounted in a position facing the recess 22 in the casing 4 for projecting and receiving light relative to the object to be detected 21 through a through hole 23, whereby operating positions of the piston 12a, or the spool 6, are detected based on the light reflected from the object to be detected 21.