Core structure of housingless-type oil cooler

Abstract

A housingless-type oil cooler includes cooling elements having first and second plates coupled with together, an oil return tube vertically arranged through a core portion, and a heat-transfer suppressing means. The cooling elements are piled up in a vertical direction of the core portion to alternately form cooling water chambers and oil chambers so that the adjacent cooling water chambers are fluidically connected through a cooling water passage and the adjacent oil chambers are fluidically connected through an oil passage. The oil return tube discharges oil introduced from one side of the core portion toward its other side through the oil chambers and the oil passages. The heat-transfer suppressing means is arranged between the oil chambers and the oil return tube to suppress heat transfer between the oil flowing in the oil chambers and the oil flowing in the oil return tube.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a core structure of a housingless-type oil cooler which has a plurality of plates piled up to form cooling water chambers and oil chambers therebetween without an additional housing so as to cool oil flowing through the oil chambers. [0003] 2. Description of the Related Art [0004] Conventional oil coolers are used for and attached to, for example, automatic transmissions to cool oil thereof. Some of the conventional ones are constructed to have an oil tube forming an oil chamber and arranged in a cooling water chamber formed between a housing of the oil cooler and the oil tube. The other conventional ones are, what is called, a housingless-type oil cooler, which is constructed to have a plurality of plates to alternately form cooling water chambers and oil chambers therebetween for removing a housing, thereby decreasing its manufacturing costs and dimensions. [0005] Specifically, suc...

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Benefits of technology

[0009] Therefore, the heat-transfer suppressing means suppresses the heat transfer from high-temperature oil in the oil chamber to the oil in the return oil tube through a wall of the oil return tube while it flows through the oil return tube. This can suppress rise in heat of the oil in the oil return tube and keep it be at the low temperature, thereby improving coolability of the oil cooler.

[0011] Therefore, the heat-transfer chambers suppress heat transfer between the oil flowing in the oil return tube and the oil flowing in the oil chambers, thereby improving coolability of the oil cooler. In addition, the cooling water in the heat-transfer cools the oil flowing through the oil return tube, further improving the coolability.

[0013] Therefore, the air, having a low heat-transfer coefficient, in the heat-transfer chambers suppresses heat transfer between the oil flowing in the oil return tube and the oil flowing in the oil chambers, thereby improving coolability of the oil cooler.

Problems solved by technology

The above known conventional core structures of the housingless-type oil coolers, however, encounter a problem in that coolability of the oil cooler deteriorates because the low-temperature oil, which is cooled by the cooling water in the cooling water chamber while it flows in the oil chambers, is reheated due to heat transfer from high-temperature oil in the oil chamber through a wall of the oil return tube while it flows through the oil return tube.

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