| 摘要 |
<p>PURPOSE:To simplify the constitution and realize a compact control valve by sliding pressure rise change-over spool and signal selector spool by signal of signal pressure port, controlling communication and non-communication of flow passage of pilot valve and tank, and selecting operation of low and high pressure set relief valves. CONSTITUTION:When no signal is input from any of signal pressure ports, 45, 47, 49, a low pressure set relief valve 9 communicates with a tank 59 and operates via flow passages, 57, 51, 53. When pressure of a hydraulic pipe 5 exceeds low set pressure of the valve 9, a pilot poppet 15 moves to the right, a valve body 21 moves to the right to open flow passages, and hydraulic oil in the hydraulic pipe 5 is discharged into a tank 11. In the same way, when A signal only is input from the port 45, the valve 9 does not operate and a high pressure set relief valve 7 operates. When signals are input simultaneously via the ports, 45, 47, the valve 9 operates. When signal is input from the port 49, the valve 9 operates. Thus, it is possible to simplify the constitution and make the control valve compact.</p> |
