| 摘要 |
PURPOSE:To prevent the reckless drive of a car by installing a pilot type selector valve which returns a direction selecting valve to a neutral position when the pressure on the input and output sides of the direction selecting valve, is low, between the direction selecting valve and the pilot valve for operating the direction selecting valve. CONSTITUTION:Pilot selector valves 18 and 20 for switching an oil passage communicating to an operating pipot valve 4 and an oil passage communicating to a drain 15 are installed into the pilot pressurized oil passages 19 and 21 of a direction selecting valve 17 for switching the direction of revolution of a hydraulic motor 3. The pilot pressure for the selector valves 18 and 20 is obtained by introducing the pressure in the conduits on the input and output sides of the direction selecting valve 17 through conduits 24, 25, 28, and 29, and the pilot pressurized oil passage of the direction selecting valve 17 is allowed to communicate to the drain only when the pressure on the both sides is low. Therefore, it the operating pilot valve is set neutral when a car travels on a descent, the direction selecting valve is automatically switched to a neutral position where an orifice 22 communicates to the output side of the hydraulic motor 3. |
