| 摘要 |
PURPOSE:To reduce power loss and stabilize control, by providing a spool valve in a center bypass passage for restricting a conduit line between the bypass passage and a tank, and connecting a pilot pipe at one end of the spool valve. CONSTITUTION:There is provided in a center bypass passage 8 a spool valve 17 for restricting a conduit line between the bypass passage 8 and a tank T. The spool valve 17 is provided with a valve chamber 21 at one end thereof and a communication hole 19 for communicating the valve chamber 21 with a terminal 12. A pilot pipe 9 is connected with the valve chamber 21. With this arrangement, pressure differential across the restriction communication with the center bypass passage 8 is set to be proportional to flow rate through the restriction. Accordingly, it is possible to reduce power loss at a neutral position and upon fine operation of a directional control valve, and stabilize control. |
