Flat Tube Making Platelike Body, Flat Tube, Heat Exchanger and Process for Fabricating Heat Exchanger

Abstract

A flat tube making platelike body 15 is in the form of a single metal plate in its entirety and comprises two flat wall forming portions 17, 18 having the same width, a connecting portion 16 for interconnecting these portions 17, 18, side wall forming portions 9, 10 projecting from the respective flat wall forming portions 17, 18 and each formed integrally with one side edge of the flat wall forming portion opposite to the connecting portion 16, and first and second reinforcing wall forming portions 11, 12 integrally formed on each of the flat wall forming portions 9, 10. The first reinforcing wall forming portions 11 are butted against the respective second reinforcing wall forming portions 12 in pairs when the metal plate is folded into a hairpin form at the connecting portion 16. The first reinforcing wall forming portions 11 are given a smaller thickness than the second reinforcing wall forming portions 12 on the other flat wall forming portion 18 butted against the respective portions 11. The platelike body 15 gives an enhanced brazing joint strength to the reinforcing wall forming portions in fabricating a flat tube, and improved pressure resistance to the flat tube to be fabricated.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is an application filed under 35 U.S.C. §111(a) claiming the benefit pursuant to 35 U.S.C. §119(e)(1) of the filing date of Provisional Application No. 60 / 559,950 filed Apr. 7, 2004 pursuant to 35 U.S.C. §111(b).TECHNICAL FIELD[0002]The present invention relates to platelike bodies useful for making flat tubes for use as heat exchange tubes for heat exchangers, such as refrigerant tubes in condensers or evaporators for motor vehicle air conditioners, oil tubes for motor vehicle oil coolers, water tubes for motor vehicle radiators and heat medium tubes for heater cores, flat tubes, heat exchangers comprising such flat tubes and a process for fabricating the exchanger.[0003]The term “aluminum” as used herein and in the appended claims includes aluminum alloys in addition to pure aluminum.BACKGROUND ART[0004]In recent years, widely used in motor vehicle air conditioners in place of conventional serpentine condensers are conde...

AI Technical Summary

Benefits of technology

[0037]With the flat tube making platelike body described in par. 1), one of the pair of reinforcing wall forming portions to be butted against each other is given a smaller thickness than the other reinforcing wall forming portion, so that when the metal plate is folded into a hairpin form at the connecting portion to butt these portions against each other, at least one side face of the thin reinforcing wall forming portion is positioned inwardly of the side face of the thick reinforcing wall forming portion. When the two reinforcing wall forming portions are brazed to each other in fabricating a flat tube, therefore, a fillet will be formed between the end faces of the two reinforcing wall forming portions and between at least one side face edge of the end face of the thin portion and the edge of the end face of the thick portion positioned outwardly of the thin portion. This prevents the formation of constriction in the fillet. Consequently, the brazing joint strength of the two reinforcing wall forming portions is greater than the brazing joint strength of the flat tube fabricated using the platelike body disclosed in the foregoing publication, giving improved pressure resistance to the flat tube.

[0048]In the case of the heat exchanger according to par. 17), the flat tubes can be given sufficient pressure resistance even if diminished in weight or size. This renders the heat exchanger smaller in size and lightweight in its entirety

Problems solved by technology

However, the flat tube making platelike body disclosed in the above publication is found to have the following problem because the corresponding pair of reinforcing wall forming portions on the flat wall forming portions are equal in thickness.

Although it appear useful to make the refrigerant tube, for example, 16 mm in width, 1.1 mm in height and up to about 0.5 mm in the wall thickness of the reinforcing wall forming portions in order to provide a compacted condenser, the above problem becomes pronounced in such a case.

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