| 摘要 |
PURPOSE:To increase the water pipe holding power by a method wherein the end of a press-molded fin is bent to intrude into a concave section of a water pipe. CONSTITUTION:A circular groove 1a is press-molded on a plate in the longitudinal direction, a part of the circular groove is made to be a recess A and flat heat receiving section 1d and 1e of the plate are bent at both sides 1b and 1c of the recess A so as to become horizontal. At the same time, a groove 2a is formed in the water pipe 2 in the longitudinal direction with the width of the groove 2a being larger than that of the recess A of the fin 1. Then, when the water pipe 2 is inserted into the circular groove 1a of the fin 1 and the recess A and the groove 2a of the water pipe are made to coincide with each other, the groove 2a of the water pipe 2 comes to lie on both sides of the recess A so as to bridge the recess. After that, both ends 1b and 1c of the recess A are bent inward to intrude into the groove 2a and fixed to the latter. As a result, the bent sections are doubled in structure so that the airtightness of the fin with respect to the water pipe is always kept normal even the temperature of the water pipe is varied during the use of the heat exchanger. |
