| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic actuator capable of obtaining a large load in the first half of an operation stroke and obtaining greater speed in the second half of the operation stroke while supplying fixed hydraulic pressure. SOLUTION: A small-diameter piston 20 is fitted slidably into a sub-cylinder 19a formed inside a large-diameter piston 19 that is fitted slidably into a cylinder 18a of a hydraulic actuator A. An oil chamber 22 is made to face the back surface of the large-diameter piston 19 and the oil chamber 22 is made to face the back surface of the small-diameter piston 20 via an oil hole 19b formed in the back surface of the large-diameter piston 19. Therefore, by only supplying the fixed hydraulic pressure to the oil chamber 22, the large load can be generated by moving the large-diameter piston 19 in the first half of the stroke of the hydraulic actuator A from Fig.2(A) to Fig.2(B) and the greater working speed can be obtained by moving the small-diameter piston 20 in the second half of the stroke of the hydraulic actuator A from Fig.2(B) to Fig.2(C). COPYRIGHT: (C)2011,JPO&INPIT |
