Heat exchanger

• US 20010010262A1
• Filed: 03/06/2001
• Published: 08/02/2001
• Est. Priority Date: 08/06/1999
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Komoda, Shuji
• Application Number:
  US09/799,456
• Publication Number:
  US 20010010262A1
• Time in Patent Office: Days
• US Class Current: 165/167
• CPC Class Codes: F28D 2021/0089 Oil coolers
• CPC Class Codes: F28D 9/0043 the plates having openings therein for circulation of at least one heat-exchange medium from one conduit to another
• CPC Class Codes: F28F 19/004 by using protective electric currents, voltages, cathodes, anodes, electric short-circuits
• CPC Class Codes: F28F 19/06 of metal
• CPC Class Codes: F28F 21/084 from aluminium or aluminium alloys

Abstract

Oil passages 113 through which oil passes are formed with plates 111, 112 composed of aluminum or an aluminum alloy in an oil cooler, according to the present invention, that is a heat exchanger with an extended life. Moreover, fins 123a composed of a material having a corrosion potential more negative than those of the plates 111, 112 are arranged in cooling water passages 123 through which cooling water, for exchanging heat with oil, passes. A sacrificial corrosive layer 301 having a corrosion potential more negative those of the plates 111, 112 and the fins 123a is formed on each of the surfaces on the sides of the cooling water passages 123 of the plates 111, 112. As a result, the sacrificial corrosive layer 301 is preferentially corroded, and not only the plates 111, 112 but also the fins 123a can be protected. Consequently, the pressure-proof strength of the oil cooler can be maintained, and the product life can be improved.

Claims

1. A heat exchanger for carrying out a heat exchange between oil and cooling water, which comprises:

a plurality of first plates and a plurality of second plates that are composed of aluminum or an aluminum alloy, and that are alternately laminated and joined by brazing;

oil passages which are each formed between one surface of one of the first plates and one surface of one of the second plates that is arranged to face the one surface of the first plate, and through which oil passes;

cooling water passages which are each formed between the other surface of the one of the first plates and one surface of one of the second plates that is arranged to face the other surface of the first plate, and through which cooling water passes; and

cooling water side fins brazed to the inner wall surfaces of the cooling water passages, wherein the cooling water side fins are composed of aluminum or an aluminum alloy having a corrosion potential more negative than those of the core layers of the first plates and the second plates, and a sacrificial corrosive layer having a corrosion potential more negative than those of the core layers of the first plates and the second plates and the cooling water side fins is formed on each of the above other surface of the first plate and the surface of the second plate that faces the above other surface of the first plate.

2. A heat exchanger according to

claim 1

, wherein the heat exchanger is an oil cooler.