| 摘要 |
PURPOSE: A pilot valve is provided to obtain large damper effect with a relatively simple structure and to sufficiently prevent hunting. CONSTITUTION: A pressure of secondary pressure channels(34,36) is raised if hydraulic pressure is transmitted to the channels(34,36) from a primary pressure channel(32) when spools(18,20) are moved down. The pressure of the secondary pressure channels is descended if the channels are communicated with second spring chambers(8,10). The oil in a fluid chamber(31) is worked to the end of the spools and a part of the oil is discharged to a third chamber(112) if the spools are moved downward. Then, the oil discharged to the third chamber is limited by a second hole(118) of a throttle channel(114), and differential pressure is generated from the fluid chamber. Therefore, the fluid chamber and the throttle channel function as a damper unit for preventing the rapid up-and-down motion of the spools to prevent the hunting thereof.
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