| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a compact and lightweight boost type cylinder device capable of reducing the number of component parts to miniaturize the device and reduce the cost. <P>SOLUTION: The boost type cylinder device comprises a booster cylinder 11 which boosts pressurized oil from a hydraulic pump 7 and feeds it to a bottom chamber 5 of a hydraulic cylinder 1, and a control valve 21 to feed the pressurized oil from the hydraulic pump 7 in a changing manner to a first pressurization chamber 16a on the returning side of a boosting piston 15 of the booster cylinder 11 and a second pressurization chamber 16b on the ongoing side, and a spool 26 for changing a flow passage of the control valve 21 is pressed against a pilot chamber 22 with a pilot plunger 32 built therein by a spring 37. A plunger chamber 39 is formed on the spring built-in side of the control valve 21, and a small plunger 40 to press the spool 26 in the same direction as the spring 37 is built in the plunger chamber 39. The plunger chamber 39 and a P-port P<SB>11</SB>to which the pressurized oil from the hydraulic pump 7 is fed communicate with each other via a communication passage 41. A throttle 43 is provided in the communication passage 41, a sequence valve which has been built in a conventional booster type cylinder device is omitted, and the booster type cylinder device is miniaturized and weight-reduced by reducing the number of component parts. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
