| 摘要 |
PURPOSE: To provide a hydraulic control valve which is simple in construction, low in cost, high in reliability, and high in safety by arranging a downward movement valve in series with an upward movement valve in a main hydraulic line for connecting a cylinder to an upward movement valve delivery port. CONSTITUTION: When an elevator is accelerated, an upward accelerating solenoid valve 11 is controlled and oil is fed into a upward movement valve pilot chamber 13 so as to pressurize an upward movement valve pilot valve. By this, the upward movement valve 10 is closed gradually. When a pump port pressure becomes higher than a cylinder port pressure, the oil delivered from a pump opens a downward movement valve 20 and flows into a cylinder 2, raising a car 1. In downward accelerated operation, a downward accelerating solenoid valve 21 is controlled to flow oil from a downward movement valve pilot chamber to a pump port so as to reduce a downward movement valve pilot chamber pressure for opening the lower movement valve. Also, after a trouble of the downward movement valve 20 is detected by some means, the upward accelerating solenoid valve 11 is controlled so as to fully open the upward movement valve 10 for stopping a car. |
