Heat exchanger

Abstract

A heat exchanger comprises a core portion including a plurality of tubes with a heat medium flowing therein and fins coupled to the outer surface of the tubes for promoting heat exchange with the heat medium, a pair of header tanks extending in a direction perpendicular to the length or the tubes at the longitudinal ends of the tubes and communicating with the tubes, and a pair of inserts arranged substantially parallel to the length of the tubes at the ends of the core portion to receive the heat transmitted from the core portion and having the ends thereof supported on the header tanks, each header tank includes a core plate with the tubes fixed thereon and a tank body providing the internal space of the tank with the core plate, and the ends of each insert are arranged outside the internal space of the tank and the insert is movably fitted in the header tank and along the length thereof and is immovable in a direction perpendicular to the length thereof.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to a heat exchanger or, in particular, to a heat exchanger effectively applicable to a multiflow radiator for cooling the cooling water of the internal combustion engine of an automotive vehicle. [0003] 2. Description of the Related Art [0004] A conventional multiflow radiator, as shown in FIG. 9, includes a core portion J4 having a plurality of tubes J2 and fins J3 coupled to the outer surface of the tubes J2, a header tank J5 communicating with the plurality of the tubes J2 and an insert J6 arranged at the end of the core portion J4 for reinforcing the core portion J4. [0005] The header tank J5 is configured of a core plate J5a coupled with the tubes J2 and a tank body J5b providing the internal space of the tank. The tubes J2 and the insert J6 are coupled to the core plate J5a by brazing after being inserted into the header tank J5. [0006] In this radiator, if the temperature of the cooling...

AI Technical Summary

Benefits of technology

The invention provides a heat exchanger that can reduce thermal distortion while maintaining the rigidity of the core portion. This is achieved by using an insert with a movable end that prevents thermal stress concentration at the coupling between the tubes and the core plate. The insert is immovable in the direction perpendicular to the direction in which thermal distortion occurs, while the header tank and the insert have a fitting structure that allows for longitudinal movement of the insert. The fins and inserts are formed of a bare material not covered by a brazing material, which eliminates the formation of a fillet and allows for improved heat transfer.

Problems solved by technology

The difference in the amount of thermal expansion between the tubes and the insert is liable to generate thermal stress due to thermal distortion at the root (coupling) between as the core plate and the tubes adjacent to the insert.

A repeated change in temperature and hence a repeated chance in thermal stress poses the problem that the tubes in the neighborhood of the root may be broken.

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