| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of shock by preventing an increase in rod acceleration.SOLUTION: This piston ring 10 is wound around a piston body 3 which is housed in a cylinder body 1 storing hydraulic fluid and which partitions a rod-side chamber R1 from a piston-side chamber R2 in the cylinder body 1. The piston ring has an outer peripheral surface 11 in a peripheral direction made to slidably contact with the inner peripheral surface of the cylinder body 1. The outer peripheral surface 11 has a plurality of grooves 12 provided at optional intervals in the peripheral direction, opened, and opposed to the inner peripheral surface of the cylinder body 1. The plurality of grooves 12 are formed in a direction along the axis direction of the cylinder body 1 or a direction inclined to the axis direction of the cylinder body 1, and communicate with one of the rod-side chamber R1 and the piston-side chamber R2. |
