HEAT EXCHANGER AND REFRIGERATION CYCLE DEVICE USING HEAT EXCHANGER

摘要

A heat exchanger has fins which are stacked in the direction perpendicular to the direction of flow of air and a heat transfer pipe (20) which penetrates through the fins and which is joined and affixed to the fins by being expanded in diameter by a pipe expansion method. High protrusions (22A) extending in the axial direction of the heat transfer pipe (20) are provided on the inner surface of the heat transfer pipe (20) so as to be arranged in the circumferential direction. Low protrusions (22B) extending in the axial direction are provided between the high protrusions (22A). After the heat transfer pipe (20) is expanded the height of the high protrusions (22A) is greater than the height of the low protrusions (22B). The opposing side surfaces of adjacent high and low protrusions (22A 22B) are formed so as to be tilted so that after the heat transfer pipe (20) is expanded lines extended from the side surfaces intersect each other on the inside of the heat transfer pipe (20).