| 摘要 |
<p>PURPOSE:To discharge a leaked oil without an exclusive drain circuit and to restrain the heating of a rotating joint, by collecting the leaked oil from a rotating joint in an oil basin and returning it to a tank with the utilization of the circuit that a pilot check valve is switched to a discharge side. CONSTITUTION:The hydraulic circuit having a rotating joint 12 is composed by containing the change valve which changes over the primary pressure side communicating to the rotating joint 12 and a discharge side circuit, the oil basin 17 which collects the oil leaked from the rotating joint 12 and the check valve unit 39 with a pilot which communicates to the discharging circuit by opening check valves 41, 42 by the primary pressure pilot of the primary pres sure side circuit that the oil basin 17 is changed over by the change valve, and is made to use a drain circuit in common with a discharge side circuit. When a press oil is fed to the primary pressure side circuit with the change valve being switched, one part of the check valve 41 (or 42) is opened by the primary pressure pilot, the oil basin 17 is communicated to the discharge side circuit and the oil is returned to an oil tank. The flow into the oil basin 17 of the leaked oil at the check valve changing time is checked by a one way valve 71.</p> |
