| 摘要 |
PURPOSE:To allow a reduction in length size by providing one or both of a fixed pressure chamber and an alternating pressure chamber in an oil pressure piston which is oscillated by means of pressure oil transferred and controlled by a spool. CONSTITUTION:When pressure oil is fed to a feed oil passage 35 through a connection port 33 from an oil pressure source, the pressure oil first enters the fixed pressure chamber 9 of a pilot valve 2 through a hole 9' and moves a spool 5 downward via an operation lever 7. The pressure oil also enters a fixed pressure chamber 23 through a feed oil port 15 and a communicating passage 27 and moves an oil pressure piston 4 upward. When a communicating passage 16 is communicated to the feed oil port 15 through a communicating chamber 20 during the upward movement of the piston 4, the pressure oil enters an alternating pressure chamber 10 through an oil passage 38 and moves the spool 5 downward. Then, the pressure oil is introduced into an alternating pressure chamber 24 through passages 11, 6, 12, 37, 22, 28 and moves the oil pressure piston 4 downward. By repeating the above operation, the oil pressure piston 4 is oscillated. |
