| 摘要 |
PROBLEM TO BE SOLVED: To provide a leader device of a pile driver which can exhibit a relatively large elevating stroke of a rotation drive unit by using ordinary hydraulic cylinders, to thereby achieve a simplified structure and the unification of an elevating speed. SOLUTION: The leader device of the pile driver is formed of: a leader 9 mounted to a base machine and having an open front surface; a movable frame 15 housed in the leader 9 in a vertically movable manner; and two hydraulic cylinders 13, 14 of the same sizes having tubes connected to the movable frame 15 and piston rods arranged in a manner vertically opposite to each other. One hydraulic cylinder 13 which has the piston rod faced downward out of the two hydraulic cylinders 13, 14, has the piston rod connected to a lower portion of the leader 9. The other hydraulic cylinder 14 which has the piston rod faced upward, has the piston rod connected to the rotation drive unit 19 for pile driving which is vertically movable along the leader 9. Then by simultaneously expanding and contracting the two hydraulic cylinders 13, 14, the rotation drive unit 19 is elevated and lowered. COPYRIGHT: (C)2008,JPO&INPIT
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