Heat exchanger

Abstract

A heat exchanger has a tank communicated with tubes at longitudinal-direction ends of the tubes. A first plate member of the tank has a core plate portion connected with the tubes and two side wall portions facing each other, which are constructed of a metal plate material. The second plate member of the tank has an opposite wall portion facing the core plate portion and two cap portions facing each other, which are constructed of a metal plate material. The core plate portion has a protrusion-shaped cross section in the longitudinal direction of the tubes. The first plate member and the second plate member are integrated by brazing. An inner surface of one of the plate members contacts an end surface of other of the plate members, and a fillet is formed between an extension portion of the one plate member and a shear droop of the other plate member.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is based on Japanese Patent Applications No. 2004-344809 filed on Nov. 29, 2004 and No. 2004-363624 filed on Dec. 15, 2004, the disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to a heat exchanger having a tank which is constructed of multiple metal plate members. BACKGROUND OF THE INVENTION [0003] Generally, referring to JP-2002-213895A, a tank of a heat exchanger is constructed of four metal plate members which are integrally joined to each other by brazing. Among the four plate members, the end plate member (core plate portion) and the tank plate member (which constructs side wall portions and opposite wall portion facing core plate portion) are respectively provided with plane-shaped junction parts, which are overlapped to be integrated by brazing. [0004] However, the construction of the tank is complicated due to the overlapped junction parts of the...

AI Technical Summary

Benefits of technology

[0013] In view of the above-described disadvantages, it is an object of the present invention to provide a heat exchanger, in which stress in tubes is restricted and a satisfactory inner capacity and a stable brazing performance of a tank are maintained.

[0015] Therefore, the brazing area between the core plate portion and the tube can be increased, as compared with the case where the core plate portion has a plane shape. Moreover, stress concentration due to a force caused by the thermal expansion difference between the tubes can be ridded, so that stress caused in the tube is reduced.

[0018] Because the inner surface of the one plate member contacts the end surface of the other plate member, the capacity of the inner space of the tank can be maintained. Moreover, the fillet is formed at the shear droop having a stable shape, so that a satisfactory brazing performance can be maintained.

[0020] Thus, the brazing parts of the tank can be reduced because the tank is constructed of the two plate members. Therefore, the further stable brazing performance can be maintained.

Problems solved by technology

However, the construction of the tank is complicated due to the overlapped junction parts of the end plate member and the tank plate member.

In this case, it is difficult to maintain the capacity of the inner space of the tank, in which refrigerant flows.

If an end surface of the one plate member is arranged to contact an inner surface of the other plate member at the brazing junction therebetween in order to maintain the capacity of the inner space of the tank, a brazing defect will be readily caused at the brazing junction.

Moreover, in the case where the second member is used as the tube plate, the surface thereof where the tubes are integrated by brazing is limited to be simple plane because the longitudinal-direction ends of the second member are to be bent to construct the seal ends of the tank.

Thus, the breakage of the tube may be caused so that inner fluid in the tube is leaked.

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