HYDRAULIC CYLINDER DEVICE

摘要

PURPOSE:To reduce a shock when a piston is stopped by a method wherein a valve capable of opening and closing a part of a hydraulic hole is arranged at a piston head and the valve is operated to close at least a part of the hydraulic hole before the piston is abutted against a cylinder end surface. CONSTITUTION:At the head part of a piston 2 is arranged a valve 12 depressed in such a direction as being projected from the head part of the piston 2. Thereby, the valve 12 closes the hydraulic hole 7 before the piston 2 is struck against the end surface of the cylinder 4, a pressure in a pressure chamber 5 between the cylinder 4 and the piston 2 is increased and the piston 2 is deccelerated at a position where the force applied to the piston 2 and the pressure in the pressure chamber 5 are balanced, resulting in that the shock generated when stopped can be reduced.