JPS5618294A - Manufacture of double heat pipe for rotary shaft - Google Patents

Abstract

PURPOSE: To improve a tight fitting property and a heat transfer characteristic, by inserting into an outer pipe an inner pipe whose one end is previously fitted with a plug and whose other end is also previously fitted with a plug coupled with a thin injection tube and by applying liquid pressure through the thin injection pipe to expand the inner pipe to tightly fit it in the outer pipe and thereafter sealing up a working liquid in the inner pipe.

CONSTITUTION: A disc plug 8 is conjoined to one end of a cylindrical metal pipe 7 and another disc plug 10 fitted with a thin injection tube 9 is conjoined to the other end to prepare an inner pipe 4. The inner pipe is inserted into an outer pipe 3 consisting of a cylindrical metal pipe 11. The inner and the outer pipes are held by a jig. A liquid pressure medium such as water is introduced under pressure into the inner pipe 4 through the thin injection tube 9 so that the inner pipe 4 is expanded and tightly fitted on the inside of the outer pipe 3. Perfect tight fitting can be effected if the inner pipe is expanded while gas is removed out of the gap between both pipes 3, 4. The liquid pressure medium is then removed. The interior of the inner pipe is cleaned up. The pipes are removed from the jig. After gas is removed out of the pipes, a working liquid 23 is injected into the inner pipe. The thin injection tube 9 is sealed up. Said mechanism results in enhancing the degree of the tight fitting and the characteristic of heat transfer.

COPYRIGHT: (C)1981,JPO&Japio