JPH10305341A - Aluminum core in heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the brazing of an engaging hole of a base plate and a tube element by molding R of a bending part on both sides of an aluminum plate material, on which brazing filler materials are cladded, to be thinner than the plate thickness, by inserting the tube element, both edge parts of which are touched to the opposed walls and the cross section of which is bending in a θ shape, in the engaging hole of the base plate, and by integrally brazing them. SOLUTION: A tube element 20 is made of an aluminum plate cladded with a brazing filler material on the surface, and the both edge parts are bent nearly vertically in the same direction by roll forming with a curve R of bending part 35 to be thinner than the plate thickness, and the front ends are touched to the opposed walls. A junction, where a welding part 21 is formed by the cladded filler metal in brazing, is placed at the center of both walls of the tube element 20. When the both side parts are connected, the front end parts, which are the both ends of the aluminum plate material, are touched to the opposed walls. Then, the tube element 20 is inserted to the engaging hole 26 and the outside surface is integrally molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum heat exchanger core used for, for example, a radiator for automobiles and a condenser.

[0002]

2. Description of the Related Art Conventionally, a tube used for this kind of aluminum heat exchanger core is disclosed in, for example, JP-A-55-1.
One disclosed in Japanese Patent No. 26365 and the like is known.
This will be described with reference to FIG. In the drawing, reference numeral 1 denotes a welding tube for an aluminum heat exchanger having a substantially θ-shaped cross section.

[0003] The aluminum heat exchanger welding tube 1 is manufactured, for example, as follows. First, as shown in FIGS. 6 (a) and 6 (b), for example, as shown in FIGS. 6 (a) and 6 (b), the aluminum plate 2 clad with a brazing material is divided into two stages and the both sides 3, 3 are substantially in the same direction. Fold it to 90 degrees. Next, the aluminum plate 2 is bent into a flat tube shape using a bending machine (not shown), and is protruded inward with the both sides 3 and 3 abutting against each other. In this state, it is fixed with a jig. Alternatively, the fins and the tubes are alternately assembled, fitted into the fitting holes of the seat plate, and fixed to the jig as a heat exchanger core. Then, it is carried into a heating furnace, heated in a heating furnace according to a conventional method, and brazed at a portion to be joined.

The brazing method is preferably a method using a non-corrosive flux, but may be a normal vacuum brazing method. Thus, the manufactured aluminum heat exchanger welding tube 1 is, as shown in FIG.
The welded portion 5 has a shape in which the both side portions 3 and 3 of the aluminum plate material 2 project inside, and can be combined with a fin material to form an aluminum heat exchanger core.

[0005]

However, as shown in FIG. 7, the welded tube 1 for an aluminum heat exchanger manufactured by this conventional method has the R portions 4, 4 on both sides 3, 3, as shown in FIG.
However, since the R becomes the same as the plate thickness of the aluminum plate 2, a concave groove 6 having a substantially triangular cross section is formed outside the welded portion 5.

Therefore, when a heat exchanger core is formed using the aluminum heat exchanger welding tube 1, a gap is formed between the heat exchanger core and the fitting hole 8 of the seat plate 7 due to the presence of the concave groove 6. In addition, when brazing to the seat plate 7, a brazing pool is not formed, and there is a possibility that liquid leakage may occur due to poor brazing. For this reason, as shown in FIG. 8, it is conceivable to provide a projection 9 on the seat plate 7 so as to cover the concave groove 6.

However, when the fitting hole 8 'is formed along the shape of the welding tube 1 made of aluminum heat exchanger, the projection 9 is formed.
May be deformed and the aluminum heat exchanger welding tube 1 may not be fitted. Therefore, in order to prevent the protrusion 9 from being deformed, it takes time and effort to manage the seat plate 7.

Further, the conventional welding tube 1 for aluminum heat exchanger has a wall surface 1 on which the tip surfaces of both side portions 3 and 3 face each other.
As shown in FIG. 9, the wall surface 10 is depressed in the direction of the tip of the side portions 3, 3 because it is away from 0. Due to this dent, poor brazing of the seat plate 7 with the fitting hole 8 is induced,
Liquid leakage easily occurs at the seat plate. The present invention has been made to solve such a conventional problem, and an object of the present invention is to reduce the radius of the bent portions at both ends of the tube element and to minimize the outer concave groove to reduce the seat plate. By making it easy to form a solder pool between the fitting hole of the seat plate and the concave groove of the tube when inserted into the fitting hole of the above, by contacting both ends of the tube element with the facing wall surface,
It is an object of the present invention to provide an aluminum heat exchanger core that can prevent dents in opposed wall surfaces.

[0009]

According to a first aspect of the present invention, an aluminum plate material having a brazing material clad on a surface thereof is formed by roll homing on both sides of the aluminum plate in the same direction by bending the R of the bent portions on both sides. A tube element having a substantially θ-shaped cross-section formed by contacting the distal end of the tube element with an opposing wall surface and a fitting hole into which the tube element is inserted is formed as follows. A seat plate made of an aluminum plate material and a straight wall surface connecting both end portions, wherein the tube element is inserted into each fitting hole of the seat plate, and a tip end portion faces the opposite wall surface. , And are integrally brazed and the outer periphery is integrally brazed with the fitting hole.

According to the first aspect of the present invention, the bent portions R on both sides of the aluminum plate material whose surface is clad with brazing material are formed to have a thickness equal to or less than the plate thickness, and both ends are brought into contact with the opposing wall surfaces. Since the bent tube element is inserted into the fitting hole of the seat plate and these are integrally brazed, the concave groove formed on the outside of the tube element becomes extremely small, and the fitting hole of the seat plate is reduced. The gap formed when inserted into the seat plate becomes small, and the brazing material clad on the seat plate and the tube element easily accumulates in this portion when brazing the seat plate and the tube element. Therefore, there is no possibility that a brazing defect occurs.

Further, since the distal end surfaces of the both sides of the tube element are in contact with the opposing wall surfaces, the insertion of the tube element into the fitting hole of the seat plate does not cause it to be dented by an external force. Brazing accuracy with holes is improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an aluminum heat exchanger core A according to an embodiment of the present invention. The aluminum heat exchanger core A has a tube element 20 having a substantially θ-shaped cross-section, a fitting hole 26 into which the tube element 20 is inserted, and connecting both side portions 261 and both end portions 261 having an arc shape. And a seat plate 25 made of an aluminum plate material, which is constituted by straight wall surfaces 262 and 262 which are formed. The tube element 20 is inserted into each fitting hole 26 of the seat plate 25 and the distal end is opposed. It is brazed integrally with the wall surface 23, and the outer periphery is integrally brazed with the fitting hole 26.

Here, the tube element 20 is made of an aluminum plate material 30 having a brazing material clad on the surface thereof.
The two sides 31, 31 are bent in the same direction by roll homing so that the R of the bent portions 35, 35 of the both sides 31, 31 are substantially perpendicular to the plate thickness or less. In contact. In addition, the tube element 20 has a joining portion 24 at a substantially central portion of both wall surfaces 22 and 23 where a welded portion 21 is formed by a brazing material clad during brazing.

On the other hand, the seat plate 25 has the same shape as a fitting hole of a normal flat tube. That is, for example, FIG.
There is no need to provide the projections 9 unlike the case described above. Next, a method for manufacturing the aluminum heat exchanger core A shown in FIG. 1 will be described. First, a long aluminum plate material 30 having a surface clad with a brazing material is prepared. Next, as shown in FIG. 3 (a), the aluminum sheet material 30 is firstly formed on both sides 31, 31 thereof by using a pair of convex rolls 40A, 40B for roll homing having a 45-degree bending angle. Bend.

Here, on the roll surface of the roll 40A, a bend forming ridge 40 having a bend angle of 45 degrees on both sides.
1, 401 are formed and both bend forming ridges 40 are formed.
A concave portion 402 having an arc-shaped cross section is formed between 1 and 401. In addition, on the roll surface of the roll 40 </ b> B, the bent portion forming corners 4 which mesh with the bent portion forming protruding edges 401, 401 having a bending angle of 45 degrees via the aluminum plate 30.
05 and 405 are formed, and a convex portion 406 having an arc-shaped cross section is formed between the corner portions 405 and 405 for forming the bent portions.

Therefore, this aluminum plate 30 is
A pair of convex rolls 40A, 40 for roll homing
B-shaped projecting edge 40 having a 45-degree bending angle of B
1 and 401 and the corners 405 and 405 for forming the bent portion are engaged with each other, so that
The bent portion can be bent five times, and the radius of the bent portion 35a can be smaller than that of the conventional process.

Next, as shown in FIG. 3 (b), a middle convex roll 4 for roll homing having a bending angle of 70 degrees.
The both sides 31, 31 are subjected to secondary bending using 1A, 41B. Here, on the roll surface of the roll 41A, a bend forming ridge 41 having a bend angle of 70 degrees on both sides.
1, 411 are formed, and the both edges 41 are formed.
A concave portion 412 having an arc-shaped cross section is formed between 1 and 411.

On the roll surface of the roll 41B, there are formed bend forming corners 415 and 415 meshing with the bend forming protrusions 411 and 411 having a bending angle of 70 degrees via the aluminum plate material 30. A convex portion 416 having an arc-shaped cross section is formed between the formed corner portions 415 and 415 for forming the bent portion. Therefore, the aluminum plate member 30 shown in FIG. 3A is formed by a pair of center-convex rolls 41A and 41B for roll homing, which have bend-forming protruding edges 411 and 411 having a 70-degree bending angle, and a bend-forming member. Corner 41
5 and 415 are engaged with each other so that both sides 31 and 3 are engaged.
1 and can be bent 70 degrees in the same direction, and the radius of the bent portion 35b can be made smaller than the bent portion 35a.

Further, as shown in FIG. 3 (c), roll homing rolls 42A having a bending angle of 90 degrees are provided.
The two side parts 31, 31 are bent at substantially 90 degrees using 42B. Here, on the roll surface of the roll 42A, the protruding edges 421 and 421 for forming a bent portion having a bending angle of 90 degrees on both sides.
421 are formed, and both bent portion forming projections 421, 421 are formed.
A plane portion 422 is formed between the 421s.

On the roll surface of the roll 42B, there are formed bend forming corners 425, 425 which mesh with the bend forming projections 421, 421 having a bending angle of 90 degrees via the aluminum plate material 30. A flat portion 426 is formed between the formed corner portions 425 and 425 for forming the bent portions. Therefore, the aluminum plate 30 shown in FIG. 3B is a pair of roll homing rolls 42A, 4A.
Bend forming ridge 42 having a 90 degree bending angle of 2B
1 and 421 and the corner portions 425 and 425 for forming the bent portion are engaged with each other, so that
The aluminum plate 30 between the bent ridges 421 and 421 and the bent corners 425 and 425 is formed as a flat portion 422 and 426.
Can be formed into a planar shape.

As shown in FIG. 4, both sides 31, 31 of the aluminum plate 30 are formed by the three stages of bending.
The R of the bent portions 35, 35 is equal to or less than the plate thickness, and the bent portion is almost 90 degrees. Next, in the aluminum plate material 30 thus bent, the both sides 31, 31 are bent in the same direction according to a conventional method, and the both sides 31, 31 are joined so that the cross-sectional shape is substantially θ-shaped.

Then, the tube element 20 is formed in such a state that the both sides 31, 31 are joined and the end faces 32, 32, which are the end faces of the aluminum plate 30 of the both sides 31, 31, are in contact with the opposing wall surface 23. Next, the tube element 20 is assembled into a core in a state where the tube element 20 is fitted in each fitting hole 26 of the seat plate 25, and is fixed to a jig.

After that, it is carried into a heating furnace and heated at a desired temperature according to a conventional method. In this way, as shown in FIG. 1, the aluminum heat exchanger core A having a small concave groove of the joint portion 27 can be obtained. That is, the contact portions 33 of the both side portions 31, the front end surface 32, the wall surface 23, the fitting hole 26 of the seat plate 25, and the outer periphery of the tube element 20 are provided. Can be integrally brazed.

As described above, according to the present embodiment, the seam portion 27 outside the welded portion 21 can be reduced, so that there is no possibility that a gap is formed between the seam portion 27 and the fitting hole 26 of the seat plate 25. No bad brazing. Further, since the welded portion 21 is in contact with the facing wall surface 23, the disadvantage that the facing wall surface 23 is depressed is eliminated. Further, in the present embodiment, in FIGS.
It was bent in the order of 70 degrees in two stages and 90 degrees in three stages. In other words, the bending angle is 45 degrees in the first stage, 25 degrees in the second stage, and 20 degrees in the third stage. The bending angle is not equal, and the bending angle is reduced toward the final stage. Therefore, it becomes possible to bend the aluminum plate material 30 without difficulty compared to the case where the aluminum plate material 30 is bent at an equal angle.

Further, in the present embodiment, FIGS.
In (c), the center convex rolls 40A, 40B, 41
A and 41B are used for bending, so that 90
The processing by the bending roll becomes reliable, and it becomes easy to form the bent portions 35, 35 having a substantially right angle. In the above embodiment, the brazing method is not particularly limited, but a brazing method using a non-corrosive flux is preferable because it is simple. When a non-corrosive flux is used, an aluminum plate material, a brazing material, or the like may be appropriately selected.

[0027]

As described above, according to the present invention, it is possible to prevent the dent of the tube when the tube element is fitted into the fitting hole of the seat plate, and to reduce the outer joints at both ends of the tube element. Therefore, brazing between the fitting hole of the seat plate and the tube element can be ensured.

[Brief description of the drawings]

FIG. 1 is an enlarged view showing an embodiment of an aluminum heat exchanger core according to claim 1;

FIG. 2 is an end view showing a tube element used for the aluminum heat exchanger core of FIG. 1;

FIGS. 3A to 3C are explanatory views showing a manufacturing process according to a method for manufacturing a tube element.

FIG. 4 is an enlarged view of a bent portion manufactured in FIG. 3 (c).

FIG. 5 is an end view of a conventional welding tube for an aluminum heat exchanger.

6 (a) and 6 (b) are explanatory views showing the steps of manufacturing the welding tube for an aluminum heat exchanger of FIG. 5;

7 is an enlarged view showing a state where the welding tube for aluminum heat exchanger of FIG. 5 is inserted into a fitting hole of a seat plate.

FIG. 8 is an enlarged view showing an example in which a fitting hole of a seat plate is deformed corresponding to a concave groove of a conventional welding tube for an aluminum heat exchanger.

FIG. 9 is an enlarged view showing a recess in a conventional welding tube for an aluminum heat exchanger.

[Explanation of symbols]

 Reference Signs List 20 tube element 21 welded portion 22, 23 wall surface 24 joint portion 25 seat plate 26 fitting hole 261 both side portions 262 wall surface 27 seam portion 30 aluminum plate material 31 side portion 32 tip surface 33 contact portion 35, 35a, 35b bent portion A Aluminum heat exchanger core

Claims (1)

[Claims] 1. An aluminum plate material with a brazing material clad on its surface, both sides of which are bent in the same direction by roll homing so that the R of the bent portions on both sides is equal to or less than the plate thickness, and the front end thereof is bent. A tube element having a substantially θ-shaped cross-section formed by contacting the opposite wall surface, and fitting holes into which the tube element is inserted are formed by arc-shaped both side portions and a linear wall surface connecting the both end portions. And a seat plate made of an aluminum plate material, wherein the tube element is inserted into each fitting hole of the seat plate, and a distal end portion abuts on an opposing wall surface and is integrally brazed, An aluminum heat exchanger core characterized in that the outer periphery is brazed integrally with the fitting hole.