| 摘要 |
PURPOSE: An outer pipe and the inner pipe are brazed with the diameter reduction of the outer pipe to the simple structure. The manufacturing process is simplified and the capital for production is reduced. CONSTITUTION: A manufacturing method of double pipe type heat exchanger comprises the following steps. A plurality of ribs is eliminated from both end part of an outer pipe(20) in which a plurality of ribs is formed in the inner circumference according to the longitudinal direction and a pair of rib-removed sections(30b) is formed. A pair of rib removing port livers is pipe-narrowed and a pair of reduced-diameter parts(32a,32b) is formed on both end part of the outer pipe. A pair of penetration holes(34a,34b) is formed on the location isolated with certain distance in a pair of short diameter portions to the inner side. The interior tubing is inserted in the outer pipe so that both end part of an inner pipe(40) expose from the outer pipe. The inner circumference of a pair of short diameter portions and outer circumference of the inner pipe are united with brazing. |
