| 摘要 |
PURPOSE:To shorten the opening and closing time of a sprue valve, by connecting a liquid pressure source to a hydraulic actuator through the sprue value and providing an accumulator between the liquid pressure source and the sprue valve while supplying a liquid to the actuator at the specific stroke position of the sprue valve. CONSTITUTION:The position 2 in the upper and lower hydraulic chambers 3H, 3L of a double-acting cylinder type hydraulic actuator 1 is connected to a test piece 4 and a hydraulic accumulator 6 is provided between the sprue valve 5 connected to the actuator 1 and a hydraulic source and the sprue 8 of the valve 5 is made movable by a cylinder 13 and a piston 14. The upper outlet port 10H of the valve 5 is connected to the chamber 3H and the lower inlet port 9L of the valve 5 to the chamber 3L while the upper inlet port 9H of the valve 5 to the accumulator 6 and, when the sprue 8 passes the open position of the valve 5 after an approach run, the liquid pressure of the accumulator 6 is supplied to the actuator 1. |
