| 摘要 |
PROBLEM TO BE SOLVED: To heighten durability of a die by means of miniaturizing a gas spring for miniaturizing a die for a punch press, enhancing a piston member guide supporting function of the gas spring, and reducing a pressure gas in the gas spring for lowering a leakage. SOLUTION: A gas spring 4 is equipped with a cylinder body 6, a piston member 7 which is outerly fitted with a punch body 3 and has a piston part 7a slidably contacted with a cylinder hole 6b airtightly at an inner side of the cylinder body 6, an end wall part 6a of the cylinder body 6, and a gas filling chamber 8 formed in the cylinder hole 6b between the piston part 7a and the end wall part 6a and filled with a high pressure nitrogen gas.
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