JP3451686B2 - Stacked heat exchanger - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, and more particularly to a laminated heat exchanger having a plurality of tubes which is effective for use in an oil cooler for vehicles.

[0002]

2. Description of the Related Art Conventionally, an aluminum laminated heat exchanger used as, for example, an oil cooler for an automobile is disclosed in Japanese Utility Model Publication No. 62-1.
No. 8857. This will be described with reference to FIGS. 5, 6 and 7. FIG. 5 shows a view of A in FIG. 1, which is a configuration diagram of an oil cooler for an automobile,
A tube 6 having an oil side passage 10 is formed by stacking the tube plates 8 and 9 together. Here, FIG. 6 shows the view D in FIG. 5, and FIG. 7 shows an enlarged view of the point E in FIG.

Oil-side fins 11 are inserted in the oil-side passage 10 of the tube 6 to improve the heat exchange performance. By the way, as shown in FIG. 9, when the tube plates 8 and 9 are press-molded, burrs 16 may occur at the peripheral end portions 17 of the tube plates 8 and 9. When the tube plates 8 and 9 are used to form the tubes 6 by superposing them as shown in FIG. 8, assembly failure may occur, leading to brazing failure. Further, in order to avoid this, even if the mating surface side of the tube plates 8 and 9 is the press droop side, the press droop amount is about 10% of the plate thickness,
In order to form a good brazing pool, the predetermined brazing quality cannot be secured because the tapered portion becomes too small. Therefore, in order to secure the brazing strength of the tube plates 8 and 9 at the peripheral end portions 17 of the tube plates 8 and 9, a mating surface (flat portion) around the tube plates 8 and 9 is provided.
A bent portion 13 bent in the opposite direction with respect to 14 is formed over the entire circumference of the tube plates 8 and 9.

[0004]

However, in the prior art, since the bent portion 13 is formed around the tube plates 8 and 9, the mating surface (flat portion) 1 of the tube plates 8 and 9 is formed.
The length of the distance P from 4 to the outermost end of the bent portion 13 was increased, and the oil-side passage area was not wide enough for the size of the tube plates 8 and 9, resulting in a wasted space.
Therefore, there is a problem that the performance is low for the physical constitution of the laminated heat exchanger.

This is because the bent portions 13 formed around the tube plates 8 and 9 contribute little to the performance of the laminated heat exchanger. Further, as shown in FIG. 9, it is conceivable to deal with burrs 16 generated during press molding of the tube plates 8 and 9 by deburring or chamfering. Since the brazing material clad on both sides is peeled off, a good brazing material cannot be formed and the brazing property deteriorates.

Therefore, in the present invention, the tube plate 8,
By eliminating the bent portion 13 formed around 9 and changing the shape of the tube plates 8 and 9, a wide oil side passage area is secured and a useless space is reduced.
The purpose is to ensure high quality brazing similar to the case where the bent portion 13 is configured during brazing.

[0007]

In order to achieve the above object, the present invention provides a laminated heat exchanger having a plurality of laminated tubes and fins, wherein the tubes are Fins are brazed to the outside, the tube has a pair of tube plates brazed together to form a fluid passage therein, and the pair of tube plates have a substantially uniform plate thickness, brazing material plate both surfaces of each have been clad, the pair
On the mating surface side of each peripheral end of the tube plate of
From the part that will be the mating surface of the tube plate
The plate thickness becomes thinner as it goes in the circumferential edge direction.
A technique in which a tapered portion is formed, and the space between the pair of tapered portions is formed such that the space expands from the mating surface of the tube plate in the circumferential end direction. To adopt the appropriate means.

Further, in the invention according to claim 2, the tapered portion of the tube plate is approximately 4 with respect to the mating surface direction.
A technical means is adopted in which the tube plate has an inclination of 5 °, and the plate thickness of the tube plate, the length of the mating surface, and the length of the tapered portion are substantially equal.

[0009]

According to the laminated heat exchanger of the present invention having the above-mentioned structure, by forming the taper portion at the peripheral end portion at the time of press-molding the tube plate, even if burrs are generated, the tube plate Since it does not affect the mating surfaces, it is possible to eliminate brazing defects due to defective tube plate assembly.

Further, in the present invention, the taper portion formed by deburring or chamfering is a taper portion formed by press working, so that the processing time of the product can be shortened and the product cost can be reduced. , A pair of taper parts clad with brazing material can form a brazing material brazing material brazing material, so that brazing of the tube plate can be performed more reliably, and high quality products can be provided. I can. Further, since it is possible to form a sufficiently large tapered portion with respect to the tapered portion using a press sag, brazing can be reliably performed in the same manner as described above, and a high quality product can be provided.

Further, since the bent portion is abolished, it is possible to improve the heat radiation performance and reduce the oil passage resistance of the oil side passage in the laminated heat exchanger of the same size, providing a high performance product. You can do it. In the invention according to claim 2, since the flatness of the mating surface can be ensured by having the mating surface having a length equal to the plate thickness of the tube plate, a good assembling when assembling a pair of tube plates. You can maintain sex. Here, for example, if the lengths of the mating surfaces are short, a gap may be created when the pair of tube plates are assembled, resulting in brazing failure. Further, if the length of the mating surface is long, a portion that does not directly contribute to the heat exchange performance becomes large like the bent portion, which is not preferable. Therefore, by setting the length of the mating surface to be equal to the thickness of the tube plate, it is possible to ensure heat exchange performance and good brazability.

Further, since the taper portion having a length equal to the plate thickness of the tube plate is provided, a favorable brazing material brazing material can be formed by the pair of taper portions formed in the pair of tube plates. It is possible. For example, if the length of the tapered portion is short, a good brazing portion cannot be formed, and the joining force between the tube plates becomes weak.
Also, when the length of the tapered portion is long, a portion that does not directly contribute to the heat exchange performance becomes large, which is not preferable. for that reason,
By setting the length of the tapered portion to be equal to the thickness of the tube plate, it is possible to secure heat exchange performance and good brazing property.

[0013]

EXAMPLE An example showing the present invention will be described below. FIG. 1 is a configuration diagram in which the laminated heat exchanger of the present invention is used in an oil cooler for automobiles. An upper end plate 3 having an inlet pipe 1 and an outlet pipe 2, a lower end plate 4 having a bracket 5 with a mounting hole 5A, and a plurality of laminated aluminum plates between the upper end plate 3 and the lower end plate 4. Tube 6 is present.

The upper end plate 3 is formed so as to communicate with the inlet pipe 1 and the outlet pipe 2, and the lower end plate 4 is integrally joined with a bracket 5 having a mounting hole 5A. And the tube 6 is shown in FIG. 2, FIG. 3 and FIG.
Has a pair of tube plates 8 and 9 which are brazed to each other, and an oil side passage 10 which is a fluid passage is formed between these tube plates 8 and 9.
Oil-side fins 11 are inserted in the oil-side passage 10.

Near both ends of each tube plate 8 and 9, cup portions 8A and 9A for communicating with the oil side passage 10 of the adjacent tube 6 are integrally formed by press working, and the cup portions 8A and 9A are formed. An oil passage hole 12 is formed in the. An oil-side passage 10 is formed inside the cup portions 8A and 9A, and an oil-side fin 11 is present therein.

Here, the tube plates 8 and 9 have a length of 227 mm in the horizontal direction and a length of 27 mm in the vertical direction.
The plate is symmetrical in the vertical and horizontal directions. Then, as shown in FIG. 4, the plate thickness L of the tube plates 8 and 9 is
Is 0.6 mm, and the length M of the flat portion 14 as the mating surface in the left-right direction is about 0.5 to 1 mm.
The length N of the tapered portion 15, which is the distance between the peripheral edge portion 17 and the peripheral end portion 17, is 0.5 mm. If the length M of the flat portion 14 becomes short, it causes brazing failure, so the minimum value is 0.5 mm.
Is specified.

Here, the mating surface described in claim 2 corresponds to the flat portion 14. The length of the mating surface according to claim 2 corresponds to the length M of the flat portion 14 in the left-right direction in FIG. The length of the tapered portion according to claim 2 is the distance between the flat portion 14 and the peripheral end portion 17 in FIG.
This corresponds to a length N of 5. The plurality of tubes 6 configured as described above are alternately laminated with the air-side fins 7.

Here, the tube plates 8 and 9 are a core material A3003 suitable for vacuum brazing, and a skin material A as a brazing material.
Using an aluminum laminated plate clad with 4004 on both sides, this was attached to a press machine for continuous processing as a hoop material, and cup portions 8A and 9A at both ends, oil passage holes 12, protrusions 13, flat portions 14 and taper were formed. The tube plates 8 and 9 having the portion 15 are continuously processed.

The oil side fin 11 and the air side fin 7 are made of aluminum alloy (A3003), which is also continuously processed by press working. The tube plates 8 and 9 and the oil-side fins 11 and the air-side fins 7 processed by the above method are washed with an organic solvent such as trichloroethylene (generally referred to as tritalene) to remove the oil adhered to the surface during press working. To be removed.

Next, the projections 13 and 1 of the tube plate 8
The oil-side fin 11 is inserted between the three and the tube plates 8 and 9 are combined to form the oil-side passage 10.
The tube 6 and the air-side fin 7 formed in this way
Are alternately superposed, the upper end plate 3 is mounted on the uppermost air-side fin 7, and the lower end plate 4 is mounted below the lowermost air-side fin 7, which is assembled as shown in FIG.

The inlet pipe 1 and the outlet pipe 2 attached to the upper end plate 3 are made of aluminum alloy (A10).
(50 materials), after performing trichlene cleaning, the upper end plate 3
Attach it to and temporarily fix it by caulking. This is the temperature 6
It is put in a vacuum heating furnace having a temperature of 00 ° C. and a vacuum degree of 10 ⁻⁴ to 10 ⁻⁵ Torr for about 10 minutes and heated. During this period, Mg added to the brazing filler metal reacts with a small amount of residual oxygen in the surrounding atmosphere and oxygen in the oxide film to become Mgo, exposing the clean surface of the aluminum base material and re-cleaning this clean surface. Prevents oxidation. That is, the brazing material clad on both surfaces of the upper end plate 3, the lower end plate 4 and the tube plates 8 and 9 is melted and gathered at each joint by surface tension to perform brazing.

In order to improve the brazing property, the tapered portion 15 greatly contributes between the flat portion 14 which is the mating surface of the tube plates 8 and 9 and the peripheral end portion 17. That is, the brazing material gathers in the taper portion 15 to form a brazing pool, which strongly joins the tube plates 8 and 9. Further, in the embodiment shown in FIG. 1, the inlet pipe 1 and the outlet pipe 2 have substantially the same function, and the fluid inlet and the fluid outlet may be opposite.

Further, in this embodiment, the peripheral end portion 17 is the flat portion 1
Although it is substantially orthogonal to 4 (vertical direction in FIG. 4), a tapered portion 15 may be provided on the opposite side of the mating surfaces of the tube plates 8 and 9. Further, the tapered portion 15 may be lengthened and the tapered portion 15 may be provided over the entire plate thickness from the mating surface side of the tube plates 8 and 9 to the opposite side. Although the present invention is applied to the oil cooler for automobiles in the present embodiment, the present invention is not limited to the oil cooler for automobiles, and other laminated heat exchangers such as condensers, evaporators, radiators, It can also be applied to intercoolers, heaters, etc.

In this embodiment, the high vacuum brazing method is used. However, an inert gas such as nitrogen or helium which suppresses the formation of an aluminum oxide film is sealed in a vacuum heating furnace. , Low vacuum degree, for example, 10 ^-1 To
Not only the low vacuum brazing method of brazing in an atmosphere of about rr but also the flux brazing method of using a flux can be used.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a laminated heat exchanger.

FIG. 2 is a partial view of the laminated heat exchanger of the present invention (A in FIG. 1).
Sight).

FIG. 3 is a tube configuration diagram of the present invention (view B in FIG. 2).

FIG. 4 is an enlarged view of the tube of the present invention (point C in FIG. 3).

FIG. 5 is a partial view of a conventional stacked heat exchanger (A in FIG. 1).
Sight).

FIG. 6 is a conventional tube configuration diagram (view D in FIG. 5).

FIG. 7 is an enlarged view of a conventional tube (point E in FIG. 6).

FIG. 8 is an enlarged view of the tube.

FIG. 9 is an enlarged view of the tube.

[Explanation of symbols]

6 tubes 7 Air side fin 8 tube plate 9 tube plate 10 Oil side passage 11 Oil side fin 14 Flat part (Mating surface) 15 Tapered part 17 perimeter

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Claims (2)

(57) [Claims] 1. A laminated heat exchanger having a plurality of laminated tubes and fins, wherein fins are brazed to the outside of the tubes, and the tubes are brazed to each other to form fluid passages inside. Having a pair of tube plates forming a pair, the pair of tube plates have a substantially uniform plate thickness,
A brazing material is clad on both sides of each plate, and the mating surfaces of the peripheral ends of the pair of tube plates are joined together.
On the side, the part that becomes the mating surface of the tube plate
Plate thickness decreases from the position toward the peripheral edge.
And a taper portion formed so that the space between the pair of taper portions expands from the mating surface of the tube plate toward the peripheral end portion. Type heat exchanger. 2. The taper portion of the tube plate has an inclination of about 45 ° with respect to the mating surface direction, and the plate thickness of the tube plate, the mating surface length, and the taper portion length are substantially equal to each other. The laminated heat exchanger according to claim 1, which has the same structure.