JP2021081128A - Heat exchanger and heat exchanger manufacturing method - Google Patents

Abstract

To prevent deterioration of heat transfer performance when a heat exchanger is manufactured.SOLUTION: A heat exchanger 100 has: a heat transfer surface A which is formed by laminating thin plates 1 and faces or contacts with a cooling object; and an internal passage R which guides a cooling medium in one direction. The heat exchanger 100 has a welding part 2 provided at a portion, which corresponds a side surface B which does not include the heat transfer surface A, on a surface along a lamination direction of the thin plates 1 and formed by welding outer peripheries of the thin plates 1 to each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat exchanger and a method for manufacturing the heat exchanger.

For example, Patent Document 1 discloses a heat exchanger formed by laminating thin plates having a plurality of holes formed so that the holes communicate with each other. In this heat exchanger, a cooling medium flows through a cooling flow path formed by communicating the holes, and the object to be cooled is cooled by exchanging heat with the cooling medium.

Japanese Unexamined Patent Publication No. 2016-85033

In a heat exchanger formed by laminating such thin plates, the thin plates are joined by diffusion bonding. The joint surface in such a thin plate is a surface orthogonal to the flow direction of the cooling medium, and the metal structure may mutate during re-hardening after diffusion bonding. One of the side surfaces formed by laminating the thin plates is a heat transfer surface that comes into contact with the object to be cooled. In the case of diffusion bonding, mutations in the metallographic structure in the heat transfer surface and cooling flow path may occur, which may hinder heat transfer.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent deterioration of heat transfer performance during manufacturing of a heat exchanger.

In order to achieve the above object, in the present invention, as the first means relating to the heat exchanger, a heat transfer surface formed by laminating a plurality of thin plates and facing or in contact with the object to be cooled is unidirectionally provided. A heat exchanger having an internal flow path for guiding a cooling medium, which is provided on a portion of a surface along the stacking direction of the thin plates and corresponding to a side surface not including the heat transfer surface, and the thin plate is provided. A configuration is adopted in which the outer periphery of each other is welded to form a welded portion.

As a second means relating to the heat exchanger, in the first means, a plurality of the welded portions are formed in the stacking direction on the side surface, and the direction orthogonal to the stacking direction and the flow direction of the cooling medium. In, a configuration is adopted in which the inner flow path is provided at a position that does not overlap with the internal flow path.

As a third means relating to the heat exchanger, in the first or second means, the welded portion is formed over three or more thin plates.

As a first means according to a method for manufacturing a heat exchanger, a press working step of pressing a thin plate having a flow path hole so as to have a predetermined shape and the flow path hole of the pressed thin plate overlap with each other. It has a laminating step of laminating a plurality of such thin plates and a welding step of joining a plurality of the thin plates by welding a part of the outer periphery of the laminated thin plates, the press working step, the laminating step and the welding step. Is repeated multiple times.

According to the present invention, it is possible to prevent mutation of the metal structure on the heat transfer surface by providing a welded portion at a portion that does not include the heat transfer surface. Therefore, it is possible to prevent a decrease in heat transfer performance during the manufacture of the heat exchanger.

It is a schematic perspective view which shows the whole of the heat exchanger which concerns on 1st Embodiment of this invention. It is a schematic plan view which shows one side of the heat exchanger which concerns on 1st Embodiment of this invention. It is a schematic cross-sectional view which shows the cross section of the heat exchanger which concerns on 1st Embodiment of this invention. It is a schematic cross-sectional view which shows the cross section of the heat exchanger which concerns on 2nd Embodiment of this invention.

Hereinafter, an embodiment of the heat exchanger according to the present invention will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the heat exchanger 100 according to the present embodiment has a substantially rectangular parallelepiped shape, and is formed by laminating a plurality of thin metal plates 1. Further, in the heat exchanger 100, a plurality of internal flow paths R are formed in one direction, and a surface along the flow direction of the internal flow path R, and a surface having a large surface area is designated as a heat transfer surface A. To. In the heat exchanger 100, an inlet opening is formed on one surface of the internal flow path R, and an outlet opening is formed on the surface facing the surface on which the inlet opening is formed. In such an internal flow path R, a cooling medium such as water circulates, and the cooling medium is guided in one direction in the heat exchanger 100. Further, the heat exchanger 100 is a surface along the flow direction of the internal flow path R, and the welded portion 2 is formed on two side surfaces B orthogonal to the heat transfer surface A. On the heat transfer surface A of the heat exchanger 100, for example, as shown by the alternate long and short dash line in FIG. 2, a power semiconductor element or a circuit board in a power module of an automobile is placed as a cooling target.

The thin plate 1 is a plate-shaped member in which a large number of flow path holes 1a (three rows in this embodiment) are formed at equal intervals. In such a thin plate 1, a flow path hole 1a is formed by press working. Further, all the thin plates 1 have flow path holes 1a formed at the same position, and the flow path holes 1a are communicated with each other at the time of stacking to form a plurality of internal flow paths R of the heat exchanger 100. Such thin plates 1 are joined to adjacent thin plates 1 by spot welding the outer periphery.

As shown in FIG. 2, the welded portions 2 are formed on two opposing sides on the outer circumference of the thin plate 1, and are provided at three locations, for a total of six locations, between the two adjacent thin plates 1. A welded portion 2 is provided between two thin plates 1 adjacent to each other in the stacking direction to form two facing side surfaces B. Such a welded portion 2 is formed by laser spot welding. Further, the welded portion 2 is provided at a position that does not overlap with the internal flow path R in the direction orthogonal to the stacking direction and the flow direction of the cooling medium. As shown in FIG. 3, the welded portion 2 has a depth that does not reach the wall surface of the internal flow path R, and as shown in FIG. 2, faces the heat transfer surface A and the heat transfer surface A. It is provided so as not to come into contact with the surface to be welded.

A method of manufacturing such a heat exchanger 100 will be described.
First, as a press working step, a metal plate formed to a predetermined thickness and having a flow path hole 1a is installed in a metal stamping apparatus. Then, the metal plate is punched by a plurality of punching tools by the metal stamping apparatus to form an opening. That is, the metal plate is processed into the thin plate 1 by the metal stamping apparatus.

Subsequently, as a laminating step, the two thin plates 1 are arranged so that all the flow path holes 1a overlap each other, and are fixed by a tool or the like. Then, as a welding step, the two laminated thin plates 1 are welded by laser spot welding on two sides of the outer circumference, that is, a portion corresponding to the side surface B. As a result, the two thin plates 1 are fixed in contact with each other on one surface.

Then, the pair of thin plates 1 formed by such a press working step, a laminating step, and a welding step are further laminated with the pair of thin plates 1 formed by the same step, and then welded. By repeating the press working process, the laminating process, and the welding process a plurality of times in this way, the plurality of thin plates 1 are laminated to form an integral heat exchanger 100.

In such a heat exchanger 100, the cooling medium is guided into the internal flow path R. Then, the cooling medium is discharged to the outside of the heat exchanger 100 while the temperature rises by transferring the heat of the power semiconductor element through the heat transfer surface A. The discharged cooling medium is cooled by an external cooling device or the like, and then supplied to the heat exchanger 100 again.

According to the heat exchanger 100 according to the present embodiment, the welded portion 2 is provided on the side surface B that does not include the heat transfer surface A. Therefore, on the heat transfer surface A, the metal structure due to welding does not change. That is, it is possible to prevent the heat transfer performance from being deteriorated by welding the thin plate 1.

Further, according to the heat exchanger 100 according to the present embodiment, a plurality of welded portions 2 are formed on the side surface B. Therefore, it is possible to more reliably join the thin plates 1 to each other. Further, the welded portion 2 is provided so as not to overlap the internal flow path R in the direction orthogonal to the stacking direction and the flow direction of the cooling medium, so that the linear distance from the internal flow path R becomes relatively long. It is possible to prevent deterioration of the heat transfer performance to the internal flow path R.

[Second Embodiment]
Subsequently, a modified example of the first embodiment will be described as a second embodiment with reference to FIG. The same components as those in the first embodiment have the same reference numerals, and the description thereof will be omitted.

The heat exchanger 200 according to the present embodiment is formed by laminating a plurality of thin plates 1 on which the flow path holes 1a are formed, as in the first embodiment. Then, the welded portion 2 is formed on the two side surfaces B with respect to the three thin plates 1 as shown in FIG. That is, the welded portion 2 is formed on the side surface B over three thin plates 1. Further, the welded portions 2 are formed at three locations each in the stacking direction and the stacking direction orthogonal to the flow direction of the cooling medium, as in the first embodiment. Two welded portions 2 are formed on one of the three thin plates 1. The welded portions 2 formed on the one thin plate 1 may overlap each other.

In such a heat exchanger 200, in the laminating process, three thin plates 1 are arranged so that all the flow path holes 1a overlap each other, and are fixed by a tool or the like. Then, in the welding step, the three laminated thin plates 1 are welded by laser spot welding on two sides of the outer circumference, that is, a portion corresponding to the side surface B. As a result, the three thin plates 1 are fixed in contact with each other on one surface.

According to the heat exchanger 200 according to the present embodiment, the welded portion 2 is formed over three thin plates 1. This makes it possible to simplify the welding process while further suppressing mutations due to welding of the metal structure.

Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The various shapes and combinations of the constituent members shown in the above-described embodiment are examples, and can be variously changed based on design requirements and the like without departing from the spirit of the present invention.

In the above embodiment, the thin plates 1 are laminated so that the flow path holes 1a completely overlap each other, but the present invention is not limited to this. For example, in the plurality of thin plates 1, the formation positions of the flow path holes 1a may be different, and the internal flow path R may be formed so as to meander. In this case, the surface area of the inner wall of the inner flow path R is increased, and the heat transfer performance to the cooling medium is improved.

In the above embodiment, the welded portions 2 are formed on two opposing sides on the outer circumference of the thin plate 1, and are provided at three locations between two adjacent thin plates 1, but the present invention is not limited to this. .. For example, one place may be provided between two adjacent thin plates 1, or four or more places may be provided.

Further, in the second embodiment, the three thin plates 1 are joined at the welded portion 2, but the present invention is not limited to this. For example, four or more thin plates 1 may be joined at the welded portion 2.

Further, in the above embodiment, the power semiconductor element and the circuit board are arranged on the heat transfer surface A, but the present invention is not limited to this, and other objects having heat may be cooled. ..

Further, in the above embodiment, water is mentioned as an example of the cooling medium, but the present invention is not limited to this. For example, the cooling medium may be a gas.

100, 200 Heat exchanger 1 Thin plate 1a Flow path hole 2 Welded part A Heat transfer surface B Side surface R Internal flow path

Claims (4)

A heat exchanger formed by laminating a plurality of thin plates and having a heat transfer surface facing or contacting an object to be cooled and an internal flow path for guiding a cooling medium in one direction.
It is characterized by having a surface along the laminating direction of the thin plates, which is provided at a portion corresponding to a side surface not including the heat transfer surface, and has a welded portion formed by welding the outer circumferences of the thin plates to each other. Heat exchanger. A plurality of the welded portions are formed on the side surface in the stacking direction, and are provided at positions not overlapping with the internal flow path in the stacking direction and the direction orthogonal to the flow direction of the cooling medium. Item 1. The heat exchanger according to item 1. The heat exchanger according to claim 1 or 2, wherein the welded portion is formed over three or more of the thin plates. A press working process in which a thin plate having a flow path hole is pressed so as to have a predetermined shape.
A laminating step of laminating a plurality of the press-processed thin plates so that the flow path holes overlap.
It has a welding step of joining a plurality of the thin plates by welding a part of the outer circumference of the laminated thin plates.
A method for manufacturing a heat exchanger, which comprises repeating the press working step, the laminating step, and the welding step a plurality of times.

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