METHOD FOR CONNECTING THIN TUBE TO HEAT TRANSFER TUBE

摘要

A method for connecting a thin tube to a heat transfer tube capable of securely maintaining the high pressure resisting strength of a connected portion between the heat transfer tube and the thin tube when the thin tube is connected directly to the heat transfer tube by brazing. In a connection structure between the heat transfer tube (12) and a capillary tube (41), a pinch part (14a) in which the tube end part (41a) of the capillary tube (41) is inserted from the anti-tube end face side of a flare part (14) and a brazing material sump part (14d) for reserving brazing material allowed to flow into the pinch part (14a) on the tube end face side of the pinch part (14a) are formed by collapsing, in a tube radial direction, only the anti-tube end face side portion of the tubular flare part (14) having a diameter larger than the diameter of the heat transfer tube (12) formed at the tube end part (12a) of the heat transfer tube (12). The tube end part (41a) of the capillary tube (41) is brazed to the heat transfer tube (12) in the state of being inserted into the pinch part (14a) from the tube end face side of the flare part (14).