| 摘要 |
<p>PROBLEM TO BE SOLVED: To inhibit expansion operation of a piston cylinder device which is not intended by a user.SOLUTION: A gas spring 1 includes: a cylinder 2 for storing a gas; a rod 3 where one end part is housed in the cylinder 2 and the other end part protrudes from an opening part of the cylinder 2, the rod 3 which moves in an axial direction of the cylinder 2; and a piston part 10 including a first free piston 71 which penetrates through the rod 3, may move relative to the rod 3, and divides a space in the cylinder 2, in which the gas is stored, into a piston side gas chamber G1 at one side and a rod side gas chamber G2 at the other side, the first free piston 71 having passages 711R, which allow the piston side gas chamber G1 and the rod side gas chamber G2 to communicate with each other, and a second free piston 72 which penetrates through the rod 3, may move relative to the rod 3, and enables the passages 711R of the first free piston 71 to open and close.</p> |
