DIRECTIONAL CONTROL VALVE DEVICE
A directional control valve device has: a plurality of spool valves; a first signal passage connected to the plurality of spool valves; and a second signal passage connected to the first signal passage at a connection site upstream from one or more of the plurality of spool valves for which shifting is to be detected.
1 . A directional control valve device comprising:
a plurality of spool valves;
a first signal passage connected to the plurality of spool valves; and
a second signal passage connected to the first signal passage at a connection site upstream from one or more of the plurality of spool valves for which shifting is to be detected.
2 . The directional control valve device of claim 1 ,
wherein the second signal passage diverges from the first signal passage at a diverging site upstream from the connection site, and
wherein the directional control valve device further comprises:
a first throttle provided in the first signal passage between the diverging site and a first spool valve from among the plurality of spool valves that is located the most upstream; and
a second throttle provided in the second signal passage between the diverging site and the connection site.
3 . The directional control valve device of claim 2 , wherein the diverging site is located upstream from the first throttle in the first signal passage.
4 . The directional control valve device of claim 2 , further comprising:
a switch valve provided in the first signal passage between the first throttle and the first spool valve, the switch valve being configured to be switched upon occurrence of a predetermined pressure; and
a pressure sensor provided in the second signal passage between the second throttle and the connection site, the pressure sensor being configured to output a signal upon occurrence of a predetermined pressure.
5 . The directional control valve device of claim 1 ,
wherein the plurality of spool valves are respectively provided in a plurality of valve blocks, and
wherein the connection site is located at an abutting surface between a pair of valve blocks among the plurality of valve blocks.
6 . The directional control valve device of claim 1 , wherein the first and second signal passages are located in a same plane that is orthogonal to an axial direction of the plurality of spool valves.