JP2005037031A - Joining structure of heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining structure for a heat exchanger capable of enhancing brazing property of a joined portion and absorbing manufacturing errors in the thickness direction of a core unit. <P>SOLUTION: In the joining structure of a heat exchanger 31 to join core units comprising a pair of heat transfer plates 36 in a multiple stage, a brazing filler metal 38 is cladded on an inner surface of the heat transfer plates 36, a communication hole 40 for communication with other core units 32 is formed in the core units 32, and a joined portion 41 returned so that a clad surface of the brazing filler metal 38 of the heat transfer plates 36 face outwardly is formed on a circumferential edge portion of the communication hole 40. The joined portion 41 is curved so as to be line-contact via the clad surface of the brazing filler metal 38, and has elasticity in the thickness direction of the core units 32. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a joining structure of a heat exchanger for joining a core unit of a heat exchange section in multiple stages.

Conventionally, some heat exchangers are configured by joining heat exchange portions in multiple stages. As this type of heat exchanger, for example, there is an intercooler 1 installed to cool air supplied to an engine with a supercharger (not shown). FIG. 3 shows a joining structure of the intercooler 1, and the intercooler 1 has a core formed by joining a thin and flat core unit 2 in multiple stages (two stages in FIG. 3 for simplicity of explanation). 3, a spacer 4 interposed between the core units 2, and a pair of end plates 5 and 6 provided so as to cover both side surfaces (upper and lower surfaces in FIG. 3) of the core 3.
The core unit 2 is formed by overlapping a pair of heat transfer plates 8 so that the hollow portion 7 is formed inside. As shown in FIG. 4, the heat transfer plate 8 has a brazing material 9 clad on the inner surface and a sacrificial material 10 clad on the outer surface in consideration of corrosion resistance. The brazing material 11 is clad on both side surfaces of the spacer 4. Further, the core unit 2 has a communication hole 12 at its end, and a plurality of protrusions 13 are formed on the outer surface closer to the center than the communication hole 12. One end plate 5 (upper side in FIG. 3) is provided with an air inlet 14 and an air outlet (not shown) at a position corresponding to the communication hole 12.
Therefore, when the core unit 2 and the end plates 5 and 6 are laminated and the sacrificial material 10 on the outer peripheral surface of the communication hole 12 and the brazing material 11 of the spacer 4 are brazed and joined, each communication hole 12 and A communication portion 15 is formed via the air inlet 11 or the air outlet, and an air flow passage 16 is formed by the communication portion 15 and the hollow portion 7. Further, between the core units 2 and between the core unit 2 and the end plates 5, 6, the projections 13 are joined together to form a cooling water flow passage 17. As a result, the air that has flowed into the core 3 from the air inlet 14 flows through the communication portion 15 and the air flow passage 16 and is cooled by exchanging heat with the cooling water flowing through the cooling water flow passage 17.

  Another example of this type of heat exchanger joining structure is a vehicular air conditioning evaporator 21 as shown in FIG. In the case of this vehicle air conditioning evaporator 21, the brazing material is clad on the inner surface of the heat transfer plate 22, and the brazing material clad surface faces the outside in the folded portion 24 formed at the peripheral edge of the communication hole 23. It has become. Therefore, the brazing material clad surfaces of the folded portion 24 can be brought into surface contact with each other and brazed, whereby the core units 25 are joined in multiple stages. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 2000-205785 (paragraph numbers 0066 and 0067, FIG. 8)

  However, among the conventional examples described above, in the former case, the sacrificial material 10 on the outer surface of the heat transfer plate 8 and the brazing material 11 of the spacer 4 are brazed, and the core units 2 are joined together. Therefore, it is difficult to improve the brazing property, and there is a possibility that leakage due to a pinhole or the like may occur. In addition, since the spacer 4 is necessary, the number of parts is increased, and the spacer 4 has a thickness of about 1.4 to 2.0 mm, has a large heat capacity, and does not easily rise in temperature, thereby improving heat exchange efficiency. There was also a problem that it was difficult to plan.

  Further, in the latter conventional example, since the folded portions 24 are in surface contact with each other, a manufacturing error in the thickness direction of the core unit 25 cannot be absorbed, and a gap is easily generated on the joint surface. There was a risk of cutting.

  The present invention has been made to solve the above-described problems, and improves the brazeability of the joint portion of each core unit, improves heat exchange efficiency, reduces the number of parts, and absorbs manufacturing errors in the thickness direction of the core unit. In addition, the present invention provides a heat exchanger joining structure capable of improving product reliability.

  The present invention relates to a heat exchanger joining structure for joining a core unit composed of a pair of heat transfer plates in multiple stages, wherein a brazing material is clad on the inner surface of the heat transfer plate, and the core unit has another core. A communication hole that communicates with the unit is provided, and a joint portion is formed on the periphery of the communication hole so that the brazing material clad surface of the heat transfer plate faces outward, and the joining portion is formed by the brazing material clad. It is characterized by being curved outward so as to be able to make line contact via a surface and having elasticity in the thickness direction of the core unit.

  According to the present invention, since the core units are in line contact with each other, and the joint portion is configured to have elasticity in the thickness direction of the core unit, the manufacturing error in the thickness direction of the core unit is absorbed. It is possible to maintain the contact pressure of the joint within an appropriate range. Therefore, it is possible to surely prevent leakage from the joining portion and improve the reliability of the product.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a simplified joining structure in a water-cooled intercooler 31 as an embodiment of a joining structure of a heat exchanger according to the present invention.

The intercooler 31 includes a core 33 formed by joining a core unit 32 having an elongated flat shape in multiple stages (in FIG. 1, two stages for simplification), and both side surfaces of the core 33 (upper in FIG. 1). And a pair of end plates 34 and 35 provided so as to cover the lower surface.
The core unit 32 is formed by overlapping a pair of heat transfer plates 36 formed in a dish shape so as to face each other. And the hollow part 37 is formed in the inside of the core unit 32, Although not shown by FIG. 1, the fin is loaded in the hollow part 37 in order to improve heat-transfer performance. As shown in FIG. 2, the heat transfer plate 36 has a brazing material 38 clad on the inner surface and a sacrificial material 39 clad on the outer surface. The core unit 32 has a communication hole 40 at its end, and the peripheral edge of the communication hole 40 is folded back so that the clad surface of the brazing material 38 faces outward to form a joint 41. The joint portion 41 is curved outward and has elasticity in the thickness direction of the core unit 32 (vertical direction in FIG. 1), and the joint portions 41 are in line contact via the brazing material 38 clad surface. It is possible. A plurality of protrusions 42 are formed on the outer surface of the core unit 32 closer to the center than the communication hole 40. Further, an air inlet 43 and an air outlet (not shown) are provided in a position corresponding to the communication hole 40 in one end plate 34 (upper side in FIG. 1).
In such a configuration, when the lower end plate 35, each core unit 32, and the upper end plate 35 are laminated in order from the lower side of FIG. 1 and the brazing members 38 of the joint portion 41 are brazed and joined, A communication portion 44 is formed through the hole 40 and the air inlet 43 or the air outlet, respectively, and an air flow passage 45 is formed by the communication portion 44 and the hollow portion 37. Further, between the core units 32 and between the core unit 32 and the end plates 34, 35, the protrusions 42 are joined to form a cooling water flow passage 46.
In this case, since the joint portions 41 are in line contact with each other and the joint portion 41 has elasticity in the thickness direction of the core unit 32, manufacturing errors in the thickness direction of the core unit 32 can be absorbed. The contact pressure between the portions 41 and the protrusions 42 can be maintained within an appropriate range. Further, since the bonding of the core units 32 is performed via the brazing material 38 clad surface, the brazing property can be improved. Therefore, it is possible to surely prevent leakage from the joining portion and improve the reliability of the product. Further, since the joint portion 41 is formed by bending the heat transfer plate 36, the manufacturing operation is simplified, the increase in the number of parts can be suppressed, and the heat transfer performance can be improved. The exchange efficiency can also be improved.

Note that the shape of the joint portion 41 is not limited to the above-described shape, and is curved outward so as to be able to make a line contact via the brazing material 38 clad surface, and has elasticity in the thickness direction of the core unit 32. Other shapes such as the shape shown in FIG. 3 may be used as long as they are formed.
Moreover, in the said embodiment, although the intercooler 31 was demonstrated, this is a mere illustration and this invention is applicable also to other heat exchangers, such as an oil cooler.

It is sectional drawing which shows the joining structure of the heat exchanger which concerns on embodiment of this invention. It is an expanded sectional view of the junction part of the heat exchanger which concerns on embodiment of this invention. It is an expanded sectional view which shows another example of the junction part of the heat exchanger which concerns on embodiment of this invention. It is sectional drawing which shows a prior art example. It is an expanded sectional view which shows a prior art example. It is sectional drawing which shows another prior art example.

Explanation of symbols

31 Intercooler 32 Core unit 36 Heat transfer plate 38 Brazing material 41 Joint

Claims (1)

A heat exchanger joining structure for joining a core unit composed of a pair of heat transfer plates in multiple stages,
A brazing material is clad on the inner surface of the heat transfer plate, a communication hole communicating with the other core unit is provided in the core unit, and a brazing material clad surface of the heat transfer plate faces outward at a peripheral portion of the communication hole. The joint portion folded back is formed, and the joint portion is curved outward so as to be in line contact via the brazing material clad surface, and has elasticity in the thickness direction of the core unit. A heat exchanger joining structure characterized by comprising:

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