CUSHION DEVICE FOR HYDRAULIC CYLINDER

摘要

PROBLEM TO BE SOLVED: To maintain enough tightening strength by a nut applied to a piston by constituting such that a collar is interposed between the piston and a step provided on a piston rod, and simultaneously to maintain a stable cushion characteristic with a cushion ring while the cushion ring is maintained in a state where the cushion ring does not directly slide on the piston rod. SOLUTION: A piston 11 is provided slidably in a cylinder 10 to apply a damping force near the stroke ends in the extension or the contraction of a piston rod 12 in the cylinder 10, and is fixed to the piston rod 12 by tightening a nut 20. A step wall 19 is provided on the piston rod 12. A collar 21 is interposed between the step wall 19 and the piston 11. A cushion ring 22 is fitted to the collar 21. The cushion ring 22 can be displaced freely between a position where the cushion ring abuts the step wall 19 and a position where the cushion ring abuts an end face of the piston 11. A one way passage 24 is formed on an end face part of the cushion ring 22 on the side that abuts the end face of the piston 11.