| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a manufacturing method for safe double vacuum bellows by which parts can be reduced and a process can be simplified/shortened and manufacture can be facilitated further and a cost can be reduced and a projecting part can also be eliminated, and a manufacturing method of a similarly applicable general sealed vacuum vessel. SOLUTION: Small diameter through exhaust holes 3e, 3e,... to precommunicate an inside space with an external part, are arranged by one or more pieces in an end part annular member 3A forming a heat insulating space part vessel. Next, an electron beam welder is arranged in an inside sealed space, and double vacuum bellows 100 are held in a work object position of the electron beam welder in a sealed work room whose pressure can be reduced up to an almost vacuum condition, and the inside of the inside sealed space is reduced in pressure and is put in a vacuum condition. While keeping the vacuum condition, its peripheral walls are melted on the whole through exhaust holes 3e, 3e,... by using the electron beam welder, and the respective through exhaust holes 3e, 3e,... are sealed. Therefore, the double vacuum bellows 100 or the other sealed vacuum vessel put in a vacuum condition after forming a cross-sectional annular ring-shaped heat insulating space part V inside of an inner-outer double concentric cylindrical part on which, for example, a central part is formed as bellows, can be manufactured.</p> |
