| 摘要 |
PURPOSE:To prevent the drop of a free piston due to wear and deterioration of a seal material, by a method wherein the size of a blind hole engaged with the free piston is made equal to the outer size of a piston, and even when the piston is moved, the free piston is prevented from movement. CONSTITUTION:A blind hole 6 extended from a piston lever 2 to a piston 3 is a staged hole having a large hole 61 and a small hole 62, a free piston 7 is engaged the large hole 61, and an oil chamber 8 is communicated to a small chamber 5 through a pore 10. A leg piece 7a of the free piston 7 is brought into contact with a bottom wall 4a of a large chamber 4, and the size of the large hole 61 is equal to the outer size of the piston lever 2. Thus, even when the piston 3 is slid, the increase and the decrease in volume of the large chamber 4 is the same as that of the small chamber 5, and the free piston 7 is not moved and can be secured. Therefore, a seal material 11 is not worn so much, the drop of the free piston 7 due to deterioration of the seal material 11 is prevented from occurring, and the quality of separation between gas in a gas chamber 9 and oil in the oil chamber 8 can be improved. |
