Stacked plate heat exchanger

Abstract

The stacked plate oil cooler has a first plate and a second plate. Both the first plate and the second plate are made of a three-layered aluminum alloy clad sheet. The second plate is folded at an outer rim to place the brazing material layer on both sides of the second plate. The first and second plates and are stacked alternately and brazed to define a water passage between sacrificial layers and, and to define an oil passage between brazing material layers. The first plate is folded at an outer rim to place the sacrificial layer on a lateral outside of a core assembly to decrease exposure of the brazing material layer to the lateral outside.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is based on Japanese Patent Application No. 2007-202024 filed on Aug. 2, 2007, the contents of which are incorporated herein by reference in its entirety.FIELD OF THE INVENTION[0002]The present invention relates to a stacked plate heat exchanger, and is preferably applied to an oil cooler for an internal combustion engine used for an automobile.BACKGROUND OF THE INVENTION[0003]Conventionally, the stacked plate heat exchanger such as an oil cooler is known in this field, also called as a housingless oil cooler. This type of oil cooler has a plurality of plates, typically made of metal such as aluminum or aluminum alloy. The plates include a first plate and a second plate formed in different shapes. The first and second plates are alternately stacked to define a plurality of passages therebetween. The passages include a first passage for coolant, such as cooling water and a second passage for hot medium, such as oil to be co...

AI Technical Summary

Benefits of technology

[0010]In view of the foregoing problems, it is an object of the present invention to provide a stacked plate oil cooler having sufficient resistance to corrosion and reliable joint of brazing.

[0011]It is a further object of the present invention to provide a stacked plate oil cooler having sufficient resistance to corrosion and reliable joint of brazing by using three-layered plates.

[0013]According to the invention, it is possible to prevent corrosion on a surface defining the first passages, since the first passages are completely surrounded by the sacrificial layers on the first plate and the second plate. Additionally, the first tapered portion and the second tapered portion enables to apply pressing force onto a brazing interface. Therefore, it is possible to improve brazing quality. Further, it is possible to achieve sufficient resistance to corrosion and reliable joint of brazing by using relatively low cost three-layered plates.

[0016]The second tapered portion may have a brazing passage corresponding to the second folded portion to introduce brazing material to an interface between the sacrificial layers on the second plate. The second plate may have a corner portion on the outer rim, and the corner portion has a recess extending at least along the second folded portion. Further, at least one of the first and second tapered portions may be formed into a U-turn shape that is easy to manufacture.

Problems solved by technology

However, this oil cooler may have a leak hole on the plate due to corrosion by moisture or chlorine.

However, this oil cooler may also have a leak hole on the plate due to corrosion, since the brazing material layer on one of the first and second plates directly faces to the passage for coolant and causes corrosion.

Further, in case of attaching a support plate on a core formed by the stacked plates, it is difficult to braze such a support plate on the core, since the sacrificial layer exposed to the outside of the core hinders a brazing.

However, it is not avoidable to increase material costs, and increase cost for the product, since the four-layered plates are required.

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