PISTON DEVICE, CRUSHER AND METHOD OF OPERATING PISTON DEVICE

To readily adjust a length of a piston device to an appropriate length.SOLUTION: A piston device 62 includes: an inner cylinder 81 in which an oil tank chamber S1 into which a compressive gas G and oil O are encapsulated is formed and which has one end in a prescribed direction faces a load device; an outer cylinder 82 provided in the other end of the inner cylinder 81 in the prescribed direction so as to be movable relatively to the inner cylinder 81 in the prescribed direction and facing a journal head; a flow passage part 86 for connecting a high-pressure chamber S2 formed between the inner cylinder 81 and the outer cylinder 82 to the oil tank chamber S1 to form a supply flow passage 86b through which the oil O circulates; and a check valve 89 provided in the supply flow passage 86b to close the supply flow passage 86b in accordance with an increase in pressure of the high-pressure chamber S2.SELECTED DRAWING: Figure 3 【課題】ピストン装置の長さを適切な長さに容易に調整することを目的とする。【解決手段】ピストン装置６２は、圧縮性ガスＧ及び油Ｏが封入される油タンク室Ｓ１が内部に形成され、所定方向の一端が荷重負荷装置と対向する内筒８１と、内筒８１の所定方向の他端に内筒８１と所定方向の相対移動が可能に設けられ、ジャーナルヘッドと対向する外筒８２と、内筒８１と外筒８２との間に形成される高圧室Ｓ２と油タンク室Ｓ１とを接続し油Ｏが流通する供給流路８６ｂが形成される流路部８６と、供給流路８６ｂに設けられ、高圧室Ｓ２の圧力の増大に応じて供給流路８６ｂを閉鎖するチェックバルブ８９と、を備える。【選択図】図３