To provide a method for producing a double-walled pipe member which does not generate an air current sound and does not increase its weight.
In the method, an inside cylindrical body 28 is molded by joining flange parts 33 and 34 for joining a first half-split member 31 and a second half-split member 32 which are formed to have approximately semi-circular cross sections to each other. By injection-molding a molten resin outside a flange 61a for an opening on the peripheral side of the inside cylindrical body 28, an outside cylindrical body 30 is insert-molded on the peripheral side of the inside cylindrical body 28, and an opening 61 is formed in a prescribed place other than the flange 61a for the opening of the inside cylindrical body 28 and the outside cylindrical body 30. On the inner surface of the prescribed place in the first half-split member 31, a support rib 63 extending from the inner surface to the inner surface of the second half-split member 32 is formed. After the outside cylindrical body 30 is insert-molded in the inside cylindrical body 28, the side of the prescribed place and the support rib 63 are removed to form the opening 61.
SASAKI YASUHIRO
Iwa Saki Kokuni
Akira Kurihara
Kawamata Sumio
Masakazu Ito
Shunichi Takahashi
Toshio Takamatsu
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