| 摘要 |
PROBLEM TO BE SOLVED: To prevent back leakage even in a refrigerating cycle using super high pressure refrigerant such as carbon dioxide, or the rattling of a valve seat member by improving a caulking structure of a copper pipe 1 and the valve seat member 2 in a check valve. SOLUTION: In the copper pipe 1, the valve seat member 2, a valve element 3 and a holder member are arranged. The valve element 3 is guided by a leg portion 42 of the holder member and seated on the valve seat member 2 when refrigerant flows in the opposite direction. In the outer periphery of the valve seat member 2, an angular groove 2a is formed which has a square sectional shape. The outer periphery of the copper pipe 1 is roll-caulked to form and caulk a caulked groove 1a which has a square sectional shape. A width W1 of the caulked groove 1a is not smaller than a width W2 of the angular groove 2a, and a depth D1 of the caulked groove 1a is not smaller than a depth D2 of the angular groove 2a. A caulked portion 1A of the copper pipe 1 is sufficiently filled in the angular groove 2a to eliminate most of a space. Besides, a large caulked portion is formed on the copper pipe to receive the end face of the valve seat member on the opposite side of the valve element. The plurality of pairs of angular grooves and caulked grooves are provided, and a plurality of thin grooves are provided around the angular grooves and caulked. COPYRIGHT: (C)2009,JPO&INPIT
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