To achieve reduction in cost of a bellows by efficiently performing bellows forming and improving mass-production performance.
In the method and apparatus for manufacturing the bellows, a metallic pipe 6 is formed into a bellows 24 in such a manner that the metallic pipe 6 is held perpendicularly by hermetically sealing the upper open part 6c and the lower open part 6d of the metallic pipe 6 with an upper die 10 and a lower die 8 respectively; a plurality of wires 14 which are fixed by joining parts 16 to the outer peripheral surface 10b of the upper die 10 are suspended; intermediate dies 20 are suspended and held with the wires 14 by fixing the plurality of the wires 14 to the outside of the intermediate dies 20 by the joining parts 16; the metallic pipe 6 is shortened by applying compressive force F, and simultaneously internal pressure P is generated to a liquid 22 in the metallic pipe 6; and bulged portions 6a of the pipe are formed by expanding the outer peripheral surface of the metallic pipe 6 in the gap between the dies outward in the radial direction by the internal pressure P.
JPS51110031U | 1976-09-06 | |||
JPS48102236U | 1973-11-30 |
US2080211A | 1937-05-11 | |||
US2222762A | 1940-11-26 |
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