JPS63242432A - Welding tube for heat exchanger and its manufacture - Google Patents

Abstract

PURPOSE:To improve the fitness of a welding tube and seat plate by bending both side parts of an Al made plate stock cladding a brazing filler metal about orthogonally, abutting the tip part to opposed wall faces and brazing it integrally. CONSTITUTION:An Al made plate stock in long size is prepd., subjected to bending orthogonally in the same direction so as to form a wall face 22 as well and after joining tip parts 31, 31 a tip 32 is abutted to the opposed wall face 23. In this case, a weld zone 21 is formed at the inside of about center part of the wall faces 22, 23 and its tip 32 is integrally brazed with the weld zone 21 as well. This welding tube 20 is inserted into the fitting hole 26 of a seat plate 25 and then the defective brazing of a brazing filler metal at brazing time is prevented because of the outside seam part 27 of the weld zone 21 becoming almost on the same level. Due to the weld zone 21 abutting to the wall face 23 the recess to the inner side of the wall face 23 is not caused. Consequently the fitness of the tube 20 and seat plate hole 26 is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a welded tube used in aluminum heat exchangers such as automobile radiators and condensers, and a method for manufacturing the same.

[Conventional technology]

Conventionally, as this type of welded tube, for example, Japanese Patent Application Laid-open No. 5
What is disclosed in JP 5-126365 and the like is known.

This will be explained based on FIG. In the figure, numeral 1 is a welded aluminum tube for a heat exchanger having a substantially θ-shaped cross section.

This aluminum heat exchanger welded tube 1 is manufactured, for example, as follows. First, an aluminum plate material 2 whose surface is clad with brazing material is prepared, for example, in FIG. 6 (a).
) and (as shown in bl), by roll homing, the both sides 3.3 are moved approximately 90 degrees in the same direction in two stages.
Fold it once. Next, this aluminum plate body 2 is bent into a flat tube shape using a bending machine (not shown), and is caused to protrude inwardly with the above-mentioned both sides 3 in contact with each other. In this state, fix it with a jig. Alternatively, the fins and tubes are assembled alternately and fitted into the seat plate, and fixed to a jig as a heat exchanger core. Then, it is carried into a heating furnace, heated in the heating furnace according to a conventional method, and the parts to be joined are brazed.

The brazing method is preferably a method using a non-corrosive flux, but a normal vacuum brazing method may also be used.

The aluminum heat exchanger welded tube 1 manufactured in this way has a shape in which the welded portion 5 protrudes inward from both sides 3 of the aluminum plate body 2, as shown in FIG. By combining with fin material, alumina can form the core of a heat control exchanger.

[Problem that the invention seeks to solve]

However, in the aluminum heat exchanger welded tube 1 manufactured by this conventional method, as shown in FIG. Therefore, a concave groove 6 having a substantially triangular cross-sectional shape is formed on the outside of the welded portion 5.

Therefore, this aluminum heat exchanger welded tube 1
When a heat exchanger core is formed using the groove 6, a gap is formed between the groove 6 and the fitting hole 8 of the seat plate 7, and when brazing with the seat plate 7, a pool of wax is sometimes formed. Otherwise, brazing may cause liquid leakage due to defects. For this reason, the 8th
As shown in the figure, when a protrusion 9 is provided on the seat plate 7 so as to close the groove 6 and a fitting hole 8' is formed along the shape of the welded tube 1 for an aluminum heat exchanger, the protrusion 9 is deformed and the aluminum There is a possibility that the welded tube 1 for the manufactured heat exchanger cannot be fitted. Therefore, it takes time and effort to manage the seat plate 7 in order to prevent the protrusion 9 from deforming.

In addition, in the conventional welded aluminum tube l for heat exchanger, since the tips of the side parts 3, 3 are separated from the opposing wall surface 9, as shown in FIG.
It is concave toward the tip.

This recess causes failure in brazing the seat plate 7 with the fitting hole 8, making it easy for liquid leakage to occur at the seat plate portion.

[Purpose of the invention]

The present invention has been made to solve the problems of the conventional art, and its purpose is to make the radius of the welded part approximately at right angles and to minimize the size of the groove on the outside, thereby making it easier to form a solder pool. Another object of the present invention is to provide a welded tube for an aluminum heat exchanger and a method for manufacturing the same, which can prevent dents in the opposing wall surface by bringing the welded portion into contact with the opposing wall surface.

[Means for solving problems]

The welded tube for a heat exchanger according to the present invention is produced by bending both sides of an aluminum plate material whose surface is clad with a brazing metal in the same direction by roll-forming, and then protruding inward with both sides in contact with each other. After that, in a welded tube for a heat exchanger with a cross-sectional shape of approximately θ, which is made by brazing the relevant joints, the both sides of the aluminum plate material whose surface is clad with brazing metal are bent approximately at right angles. It is bent, and its tip is integrally brazed to the opposing wall surface.

Further, the method for manufacturing a welded tube for a heat exchanger according to the present invention includes bending both sides of an aluminum plate material whose surface is clad with a brazing material in the same direction by roll homing, and then bringing the both sides into contact with each other. In the method of manufacturing a welded tube for a heat exchanger with a cross-sectional shape of approximately θ by protruding it inward and then brazing the corresponding joint, an aluminum plate material whose surface is clad with a brazing metal is used. , when bending both sides thereof substantially at right angles in the same direction by roll homing, the roll homing is performed in at least three stages.

[Action of the invention]

In the present invention, since both sides of an aluminum plate material whose surface is clad with brazing metal are bent at approximately right angles, the groove formed on the outside of the welded part is extremely small, and the seat plate The gap formed when the tube is inserted into the fitting hole becomes smaller, and when brazing the seat plate and aluminum welded tube for heat exchangers, the filler metal clad on the seat plate and aluminum plate body tends to accumulate in this area. Become. Therefore,
Brazing eliminates the risk of defects. In addition, since the ends of both sides of the aluminum plate forming the welding part are in contact with the opposing wall surface, after inserting into the fitting hole of the seat plate,
There is no denting due to external force, and the accuracy of brazing with the fitting hole of the seat plate is improved.

Further, according to the present invention, since roll homing is performed in at least three stages, the R portions formed on both sides of the aluminum plate are approximately 90 degrees, and the curves formed on the outside when the both sides are joined. There is almost no gap between the joints.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be explained based on the drawings in which the present invention is implemented.

FIG. 1 shows an aluminum heat exchanger welded tube 20 according to this embodiment. This aluminum heat exchanger welded tube 20 has a substantially θ-shaped cross section, and both wall surfaces 22
．． A welded portion 21 is formed inside the substantially central portion of the welded portion 23 . This welding part 21 is made by bending the aluminum plate 30 constituting one wall surface 22 at approximately 90 degrees in the same direction, joining both side parts 31 and 31, and joining the tip part 3.
2 is brought into contact with the opposing wall surface 23. Note that the welded portion 21 is integrally brazed to the tip portion 32 thereof.

When the aluminum heat exchanger welded tube 20 constructed in this way is inserted into the fitting hole 26 of the seat plate 25, for example as shown in FIG. 27 are almost flush, so that the brazing material can be sufficiently spread during brazing, and no defects will occur during brazing. Furthermore, since the welded portion 21 is in contact with the opposing wall surface 23, the wall surface 23 is prevented from denting inward. Therefore, when inserted into the fitting hole 26 of the seat plate 25, it is possible to prevent the wall surface 23 from denting inward due to external force.

Next, a method for manufacturing the aluminum heat exchanger welded tube 20 shown in FIG. 1 will be described.

First, a long aluminum plate 30 whose surface is clad with a brazing material is prepared.

Next, this aluminum plate body 30 is shown in FIG. 3(a).
As shown in FIG.
1 is subjected to primary bending. Next, as shown in FIG. 3(b), the both sides 31.31 are subjected to a secondary bending process using rolls 41.41 for roll homing having a bending angle of 70 degrees. Further, as shown in FIG. 3(C), a roll 42 for roll homing having a bending angle of 90 degrees.
42 to bend both sides 31 and 31 at approximately 90 degrees.

Through these three stages of processing, as shown in Fig. 4, the R of the bent portion of both sides 31.
It has become a degree.

Next, the aluminum plate body 30 that has been bent in this manner is bent on both sides 31.31 in the same direction according to a conventional method, so that the cross-sectional shape is approximately θ-shaped.
31 is joined.

Then, while the both side parts 31.31 are joined, the tip part 32.32 is fixed with a jig in a state in contact with the opposing wall surface 23, or the core is assembled and fitted into the fitting hole of the seat plate. It is fixed to the jig in this state.

Thereafter, according to a conventional method, it is carried into a heating furnace, heated at a desired temperature, and each joint portion is brazed.

In this way, the aluminum heat exchanger welded tube 20 shown in FIG. 1 can be obtained.

As described above, according to the present embodiment, the outer joint portion 27 of the welded portion 21 can be made small, so there is no possibility that a gap will be formed when the joint portion 27 is inserted into the fitting hole 26 of the seat plate 25. attached will not cause defects. In addition, since the welded portion 21 is in contact with the opposing wall surface 23, the opposing wall surface 23
This eliminates the problem of denting.

In the above embodiments, the brazing method is not particularly limited, but brazing using non-corrosive flux is preferable because it is a simple method. When a non-corrosive flux is used, the aluminum plate, brazing material, etc. may be appropriately selected accordingly.

〔Effect of the invention〕

As described above, according to the present invention, the joint on the outside of the weld can be made small, so the fitting hole of the seat plate can be a fitting hole of an ordinary flat tube, and the seat plate can be seated with normal management of the seat plate. The fitability of the plate into the fitting hole is improved, and the airtightness with the fitting hole of the seat plate is also improved.

[Brief explanation of drawings]

Fig. 1 is an end view showing an embodiment in which the welded tube for heat exchanger according to the present invention is applied to the welded tube for aluminum heat exchanger, and Fig. 2 shows the welded tube for aluminum heat exchanger according to the same embodiment. An enlarged view showing the state inserted into the fitting hole of the seat plate; FIGS. 3(a) to (C) are explanatory views showing the manufacturing process of the welded tube for a heat exchanger according to the present invention;
The figure is an enlarged view of the bent part manufactured in Figure 3 (C),
The figure is an end view of a conventional welded tube for an aluminum heat exchanger, Figures 6 (a) and (b) are explanatory diagrams showing the manufacturing process of the welded tube for an aluminum heat exchanger, and Figure 7 is an end view of a conventional welded tube for an aluminum heat exchanger. An enlarged view showing a state in which a welded tube for a heat exchanger made of aluminum is inserted into a fitting hole in a seat plate. Figure 8 shows a fitting hole in a seat plate that corresponds to the concave groove of a conventional welded tube for a heat exchanger made of aluminum. Enlarged view showing a modified example of , No. 9
The figure is an enlarged view showing a recess in a conventional aluminum heat exchanger welded tube. 20...Aluminum welded tube for heat exchanger, 2
1... Welding part, 22, 2.3... Wall surface, 25...
Seat plate, 26... Fitting hole, 27... Joint part, 30...
- Aluminum plate body, 31...side part, 32...tip part, 40, 41.42...roller for roll home. Figure 1 Figure 2 Zb (Kindai Rei) Figure 5 Figure 6 (Q) (b) Figure 7 Figure 8 Figure 9

Claims (3)

[Claims] (1) An aluminum plate material whose surface is clad with brazing material is bent on both sides in the same direction by roll-homing, then protruded inward with both sides in contact, and then the corresponding contact area is brazed. In the welded tube for a heat exchanger, which has a substantially θ-shaped cross-sectional shape, both sides of an aluminum plate material whose surface is clad with brazing material are bent at substantially right angles, and the tips thereof are placed opposite each other. A welded tube for a heat exchanger that is integrally brazed to a wall surface. (2) An aluminum plate material whose surface is clad with brazing material is bent on both sides in the same direction by roll-homing, then protruded inward with both sides in contact, and then the corresponding contact area is brazed. with a cross-sectional shape of approximately θ
In a method for manufacturing a welded tube for a heat exchanger having a shape, an aluminum plate material whose surface is clad with a brazing material is bent at approximately right angles in the same direction on both sides by roll forming, in at least three stages. A method for manufacturing a welded tube for a heat exchanger, which comprises rolling homing. (3) When bending both sides of an aluminum plate substantially at right angles in the same direction by roll homing,
The method for manufacturing a welded tube for a heat exchanger according to claim 2, wherein the welded tube for a heat exchanger is formed separately into a step of bending at approximately 45 degrees, a step of bending at approximately 70 degrees, and a step of bending at approximately 90 degrees. .