Heat exchanger and method of manufacturing the same

Abstract

A heat exchanger includes at least one tube provided with an inner fin in a fluid passage which is defined by the tube therein and has a substantially ellipse-shaped cross section. A plate member for constructing the tube has two edge portions, which overlap each other and are integrally joined at a single joint disposed at a major-axis direction end of the tube. The inner fin is arranged in the tube before the forming of the joint, thus improving an arrangement performance of the inner fin. Moreover, there exists the single joint positioned at the one end of the tube so that a joint reliability of the tube is enhanced.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is based on a Japanese Patent Application No. 2004-309939 filed on Oct. 25, 2004, the disclosure of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to a heat exchanger and a method of manufacturing the heat exchanger, in which a tube is provided with an inner fin therein. BACKGROUND OF THE INVENTION [0003] Generally, an inner fin can be arranged in a tube of a heat exchanger, for example, referring to JP-2003-28586A. In the manufacture of the heat exchanger, a pair of plates having a substantially ⊃-shaped cross section are confronted with each other to be engaged, while the inner fin is positioned therebetween. Thereafter, a joining of the two plates and a joining of the inner fin to the two plates are performed by brazing through a brazing material paste, which is applied to surfaces of the two plates. Thus, the tube in which the inner fin is joined to an inner sur...

AI Technical Summary

Benefits of technology

The present invention provides a heat exchanger and a manufacturing method that improves the joint reliability of the tube while maintaining the arrangement performance of the inner fin. The heat exchanger includes at least one tube and at least one inner fin. The tube is constructed of a plate member and defines therein a fluid passage having a substantially ellipse-shaped cross section. The inner fin is arranged in the tube and joined thereto by brazing. The tube has a single joint, which is continuous in a longitudinal direction of the tube and positioned at a major-axis direction end of the tube. The inner fin can be inserted in the tube from the side of this major-axis direction end, before the joint is formed. The method includes a forming process for bending the plate member to form a tube body, a first joining process for integrally joining the tube body to form a tube, an arranging process for disposing the inner fin before the forming process at a position where the fluid passage defined by the tube body is to be formed, and a second joining process for integrally joining the inner fin to an inner surface of the tube by brazing. The joint reliability of the tube is enhanced by the single joint positioned at the one major-axis direction end of the tube.

Problems solved by technology

However, because the flow of the brazing material in the brazing is not satisfactory at the position where there exists a relatively large gap between the plates due to a plate distortion or the like, a joint defect easily occurs.

Thus, a fluid leakage from the heat exchanger may be caused.

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