Heat exchanger

摘要

A heat exchanger has a flat tube (10) having a curved portion (13). A part of the curved portion (13) is formed by overlapping an outer rim (22) on an inner rim (21). The inner rim (21) has a small curvature region (102). The small curvature region (102) is inclined to a flat plate portion (11), and is defined by a radius larger than a difference between a half of a thickness of the flat tube (10) and a thickness of the outer rim (22). The small curvature region (102) is not beyond a center line (C1) in a thickness of the flat tube (10). The outer rim (22) extends beyond the center line (C1). The outer rim (22) has an end face (22a) placed on the small curvature region (102). The flat tube (10) has flared portions (15, 16) expanded at insertion holes (54).

主权项

1. A heat exchanger having a flat tube made of a metal plate that has an overlapped curved portion on an end in a cross section, wherein the flat tube comprises:
a first planar wall and a second planar wall defining a thickness of the flat tube, a center plane of the flat tube being defined midway between the first and second planar walls, the center plane extending in a direction parallel to the first and second planar walls; an inner rim placed inside of an outer rim; the outer rim placed on an outside of the inner rim; a small radius region formed on the inner rim; a large radius region formed on the inner rim having a larger radius than the small radius region; wherein an end face of the outer rim is placed on the large radius region at an approximate mid-point of the large radius region of the inner rim; a thickness of the outer rim is equal to a thickness of the inner rim at an intersection with the center plane; a thickness of the outer rim becoming thinner from a first point located between the intersection with the center plane and an end face of the outer rim to a second point located at the end face of the outer rim; and the first point on the outer rim and an end face of the inner rim are located on opposite sides of the center plane.