| 摘要 |
A check valve (33) is provided downstream of a filter member (F3) for preventing, by means of a filter (32) provided at an opening having an outer periphery surrounded by a frame (31), the entry of foreign matter which is contained in hydraulic fluid, the check valve having a part formed integrally with the frame (31) and being configured so that the outer peripheral surface (34a) of the check valve and the inner peripheral surface (31a) of the frame (31) move away from and come into contact with each other to open and close the check valve, thereby preventing the back flow of the hydraulic fluid. |
