| 主权项 |
1. A single-acting fluid pressure cylinder that extends upward in accordance with supply of a working fluid to a driving chamber below a piston sliding inside a cylinder tube, and that has a cushioning function for suppressing an extension operation before the piston reaches an extension stroke end, the fluid pressure cylinder comprising:
a piston rod that is joined to an upper portion of the piston with an in-rod chamber defined between the piston rod and the piston; a cushioning chamber defined between the piston rod and the cylinder tube, the cushioning chamber being configured to decrease in capacity in accordance with extension of the fluid pressure cylinder; a communication passage formed in the piston rod, the communication passage being configured to allow the cushioning chamber and the in-rod chamber to communicate with each other; a throttle passage formed below the communication passage, the throttle passage being configured to exert the cushioning function by applying resistance to a flow of the working fluid from the cushioning chamber to the in-rod chamber; a check valve provided in the piston, the check valve being configured to allow the in-rod chamber and the driving chamber to communicate with each other, the check valve being configured to have a checking function for permitting only a flow of the working fluid from the in-rod chamber to the driving chamber; and a pilot passage formed in the piston, the pilot passage being configured to disable the checking function by guiding a pressure in the cushioning chamber to the check valve as a pilot pressure. |
