JPH11325783A - Heat exchanger and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent harmful deformation, e.g. tilting of fin, prior to collective brazing and to protect the brazed part between a tube and a side plate against destruction due to difference of thermal elongation/contraction. SOLUTION: Flat tubes 11 are arranged in parallel at a predetermined interval, fins 12 are arranged between respective heat exchanging tubes 11 and on the outside thereof, a side plate 14 is arranged on the outside of the outermost fin 12 and then they are integrated through collective brazing under a state where the forward end 14b at the bent end 14a of the side plate 14 abuts against the outermost tube 11. In such a heat exchanger, a breakage inducing part 20 comprising a groove 21 and a cut 22 is provided at an intermediate part in the longitudinal direction of the side plate 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger made of a metal such as aluminum which is preferably used for a condenser for a car cooler, and a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, as a condenser for a car cooler, a so-called multi-flow type heat exchanger made of aluminum tends to be used favorably. In this heat exchanger, as shown in FIG. 4, a plurality of flat tubes (1) for heat exchange are arranged in parallel at predetermined intervals, and the flat tubes (1) between the flat tubes (1) and the outermost flat tubes are arranged. Fins (2) are arranged outside the tube (1), and a side plate (4) for protecting the fins (2) is arranged outside the outermost fin (2). Also, both ends of each tube (1) are a pair of hollow headers (3)
(3) is connected in communication. In addition, (5) is a partition member for flowing the refrigerant in a meandering manner along the tube (1) group, and (6) and (7) are unions for the refrigerant inlet and outlet.

[0003] Such a heat exchanger comprises a tube (1),
Fins (2), headers (3), side plates (4)
And other heat exchanger components (1) to (7) are combined with each other, and further banded so as to be tied around the outer sides of both side plates (4) and (4). Manufactured by batch brazing.

[0004]

By the way, in the heat exchanger as described above, both side plates (4) and (4) are in a tentatively assembled state by tension of a band for banding.
A force acts such that is pressed inward. For this reason, as shown in FIG. 5, for example, when a side plate (4) whose end bent portion (4a) is shorter than the height of the fin (2) is used, Since the bent portion tip (4b) is arranged at a distance from the outermost tube (1), a strong pushing force due to the tension of the band acts on the outermost fin (2), and as shown in FIG. As shown, the fin (2) is pushed inward and tilts,
There is a possibility that harmful deformation such as fin collapse may occur.

Therefore, in order to prevent the fins from falling down, as shown in FIG.
The end bent portion (4a) having a length substantially equal to that of the fin (2) is used, and the end bent end (4b) is brought into contact with the outermost tube (1) to form a band. There is a case where the tension of the band is received by the outermost tube (1) to prevent harmful deformation such as falling of the fin.

However, in this configuration, the end (4b) of the end bent portion of the side plate (4) is fixed to the tube (1) by brazing, while the side plate (4) is connected to the side plate (4). Since the expansion and contraction amount due to thermal expansion is significantly different from that of the tube (1), for example, when the heat exchanger is operated, the heat exchange tube (1) expands and contracts significantly with respect to the side plate (4) due to thermal expansion. Therefore, as shown by the imaginary line in FIG.
It concentrates on the brazing part (8) between the end bent part (4b) of the side plate (4) and the tube (1), cracks occur in the brazing part (8) and breakage occurs, and depending on the case, Has a problem that refrigerant leakage occurs.

[0007] The present invention solves the above-mentioned problems of the prior art, and can prevent harmful deformation such as falling down of the fin.
An object of the present invention is to provide a heat exchanger and a method for manufacturing the same, which can prevent breakage of a brazed portion between a tube and a side plate due to a difference in thermal expansion and contraction amount.

[0008]

According to a first aspect of the present invention, there is provided a heat exchanger in which a plurality of heat exchange tubes are arranged in parallel at predetermined intervals. The fins are arranged between the tubes and outside the outermost heat exchange tubes, while the side plates are arranged outside the outermost fins. In a heat exchanger that is integrated by batch brazing while being in contact with the heat exchange tube of
The gist is to provide a fracture inducing portion having a smaller sectional area than other portions.

In the heat exchanger according to the first aspect of the present invention, the end of the bent portion of the side plate is brought into contact with the outermost heat exchange tube. Even if the side plate is pushed inward, the pushing force is received by the heat exchange tube, and the fin is not adversely affected by the pushing force.

[0010] Also, at the middle portion in the length direction of the side plate,
Since the cross-sectional area is smaller than the other parts, for example, a thin and / or narrow break inducing portion is provided, during operation of the heat exchanger, the heat exchange tube thermally expands and contracts to the side plate in the expansion and contraction direction. When an overstress is applied along the rupture, the rupture inducing portion is broken, and the side plate is divided. Since each of the divided pieces of the side plate moves following both ends of the heat exchange tube, stress due to thermal expansion and contraction is concentrated on the brazed portion between the end of the bent portion of the side plate and the tube. Can be prevented.

However, in the heat exchanger of the present invention, in order to more reliably prevent the stress concentration at the brazing portion, after the collective brazing, the fracture inducing portion is cut by an appropriate means. It may be provided for use. In addition, since the break induction | stimulation part of a side plate is comprised by the part whose cross-sectional area is smaller than other parts, for example, a thin part and / or a narrow part, when cutting | disconnecting a side plate, it can cut easily. it can.

On the other hand, in the method for manufacturing a heat exchanger according to the second aspect of the present invention, a plurality of heat exchange tubes are arranged in parallel at predetermined intervals, and a space between each of the plurality of heat exchange tubes and at the end thereof. While placing the fins on the outside of the outer heat exchange tube,
A side plate is arranged outside the outermost fins, and the end of the end bent portion of the side plate is brought into contact with the outermost heat exchange tube, and the heat is integrated by brazing all together. In the manufacturing method of the exchanger, as the side plate, in the middle portion in the length direction, using a break inducing portion having a smaller cross-sectional area than other portions is used, after performing the collective brazing, The gist is to cut and separate the side plate at the break inducing portion.

The manufacturing method according to the second aspect of the present invention specifies one aspect of the manufacturing process of the heat exchanger according to the first aspect.

[0014]

FIG. 1 is a front view showing an upper part of an aluminum multi-flow heat exchanger according to an embodiment of the present invention. As shown in the figure, this heat exchanger is provided between a plurality of flat tubes (11) for heat exchange arranged in parallel at predetermined intervals and outside the outermost flat tube (11). The fins (12) are arranged respectively, and both ends of each tube (11) are connected to a pair of hollow headers (13) (13) in a communicating state.

On the outside of the outermost fin (12),
Side plate (1) for protecting fins (12)
4) is arranged. This side plate (14)
As shown in FIGS. 1A and 2, a V-shaped cut groove (21) is formed in the middle part in the length direction along the width direction, and both side parts of the cut groove (21). A V-shaped notch (22) is formed in the cutout groove (21) and a portion in which the notch (22) is formed.
0) is configured.

The bent portions (14a) (14a) at both ends of the side plate (14) are dimensioned such that the length (L) thereof is equal to the height of the fin (14).

This heat exchanger comprises a tube (11), a fin (12), a header (13), a side plate (1).
4) and the like are combined with each other, and further, the both side plates (14) are banded so as to be wound from the outside to form a temporary assembly.

In the temporary assembled state, as described above, since the end bent portion (14a) of the side plate (14) is set to the same length as the fin (12), the end bent portion (14) is formed. The tip (14b) of 14a) is arranged in contact with the outermost tube (11). Therefore, both side plates (1
Even if 4) is pushed inward, the pushing force does not act on the fins (12) and is received by the tube (11), so that harmful deformation such as the fins (12) falling down is prevented.

In the present embodiment, the heat exchanger components in the temporarily assembled state are integrated by performing collective brazing in a furnace to produce a heat exchanger.

Needless to say, by the above brazing process, the bent portion tip (14) of the side plate (14) is formed.
b) is brazed and fixed to the outermost flat tube (11).

In this heat exchanger, a notch (21) and a notch (2) are provided at an intermediate portion of the side plate (14).
Since the rupture inducing portion (20) composed of (2) is provided, during the operation of the heat exchanger, overstress is applied to the side plate (14) along the direction of expansion and contraction due to the thermal expansion and contraction of the flat tube (11). And the fracture inducing portion (2
0) is broken and the side plate (14) is divided into two. Since each of the divided pieces of the side plate (14) follows both ends of the flat tube (11), it moves, so that the end (14) of the end bent portion of the side plate (14).
It is possible to prevent stress due to thermal expansion and contraction from being concentrated on the brazing portion between the b) and the tube (11). Accordingly, no crack is generated in the brazed portion, and destruction can be prevented, and problems such as refrigerant leakage can be reliably prevented.

Further, the heat exchanger of the present embodiment can be realized by a simple structure in which the cut groove (21) and the notch (22) are provided in the side plate (14). It is possible to maintain high production efficiency without complicating the production, and avoid an increase in cost.

Further, in the heat exchanger of the present embodiment, in the state before actual use, the undivided rigid side plate (14) is arranged outside the outermost fin (12). Fin (12) due to (14)
Can be reliably protected.

Further, in the present embodiment, since adverse effects due to the difference in the amount of thermal expansion and contraction between the side plate (14) and the tube (11) can be avoided, the side plate (14)
The fin (12) can be more reliably protected by using a thicker and more rigid material.

In the present embodiment, the cut groove (2) as a break inducing portion (20) of the side plate (14) is used.
1) is formed so as to open outward, so that the brazing material does not penetrate from the fins (12) into the cut grooves (21) and is filled during brazing. Thus, the function as the break inducing portion (20) can be reliably exhibited.

Incidentally, in the heat exchanger of the present embodiment, in order to more reliably prevent stress concentration at the brazing portion between the side plate (14) and the tube (11), the side plates are collectively brazed. Plate (14)
May be cut at the rupture inducing section (20) and divided into two parts to be used for actual use.

When the side plate (14) is cut in this way, since the break inducing portion (20) is constituted by the cut groove (21) and the notch (22), it can be easily and accurately formed by a suitable tool. Can be cut.

As a method for cutting the side plate (14), for example, as shown in FIG.
The tool (30) having 1) is attached to the side plate (14).
The method of pressing and cutting along the laminating direction of the heat exchanger core from the outside to the fracture inducing section (20) in the above is preferably adopted.

In the above embodiment, the break inducing portion (20) is constituted by the cut groove (21) and the notch portion (22). However, the present invention is not limited to this. (21) or notch (22), and may be constituted by a group of perforated holes other than slits and through holes. You may comprise. In short, it is only necessary that the fracture inducing portion is configured to have a smaller sectional area than other portions.

In the above embodiment, the case where one break inducing portion is provided on the side plate is described. However, a plurality of break inducing portions may be provided.
The side plate may be divided into three or more.

[0031]

As described above, according to the heat exchanger of the first aspect of the present invention, the end of the bent portion of the side plate is brought into contact with the outermost heat exchange tube. When attaching, even if the side plate is pushed inward by the tension of the band for banding, the pushing force is received by the heat exchange tube, and the fin is not adversely affected by the pushing force. Such deformation can be reliably prevented. In addition, a break inducing section having a smaller cross-sectional area than other parts is provided at the middle part of the side plate in the length direction, so that the heat exchange tube expands and contracts in When an overstress is applied along the line, the fracture inducing portion is broken and the side plate is divided, and each divided piece of the side plate moves following both ends of the heat exchange tube. Therefore, stress due to thermal expansion and contraction can be prevented from concentrating on the brazed portion between the end of the end bent portion of the side plate and the tube, and failure such as breakage due to stress concentration can be reliably prevented.

However, in the heat exchanger of the present invention,
In order to more reliably prevent the destruction of the brazed part,
After the collective brazing, the fracture inducing portion may be cut by an appropriate means and provided for actual use. In addition,
Since the break inducing part of the side plate is composed of an area with a smaller cross-sectional area than the other parts, when the side plate is cut, it can be easily cut, which complicates work. There is no.

The method for manufacturing a heat exchanger according to the second aspect of the present invention specifies one aspect of the manufacturing process of the heat exchanger according to the first aspect of the present invention, and therefore the same effects as described above can be obtained. .

[Brief description of the drawings]

FIG. 1 is a front view showing an upper part of a heat exchanger according to an embodiment of the present invention.

FIGS. 2A and 2B are views showing a side plate employed in the heat exchanger of the embodiment, wherein FIG. 2A is a front view and FIG.
Is a plan view.

FIG. 3 is an enlarged line sectional view showing the vicinity of a fracture inducing portion in a side plate of the embodiment.

FIG. 4 is a front view showing a heat exchanger.

FIG. 5 is a front view showing the vicinity of an end of a side plate in a conventional heat exchanger.

FIG. 6 is a front view showing the periphery of an end of a side plate in another conventional heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Tube 12 ... Fin 14 ... Side plate 14a ... End bending part 14b ... Tip 20 ... Break induction part

Claims (2)

[Claims] 1. A plurality of heat exchange tubes are arranged in parallel at a predetermined interval, and fins are arranged between each of the plurality of heat exchange tubes and outside of an outermost heat exchange tube. A side plate is arranged outside the outermost fins, and the end of the end bent portion of the side plate is brought into contact with the outermost heat exchange tube, and heat is integrated by batch brazing. In the heat exchanger, a break inducing portion having a smaller cross-sectional area than other portions is provided at an intermediate portion in a length direction of the side plate. 2. A plurality of heat exchange tubes are arranged in parallel at predetermined intervals, and fins are arranged between each of the plurality of heat exchange tubes and outside of an outermost heat exchange tube. A side plate is arranged outside the outermost fin, and a tip of an end bent portion in the side plate is in contact with the outermost heat exchange tube,
In the method for manufacturing a heat exchanger integrated by performing brazing at once, as the side plate, a side plate provided with a fracture inducing portion having a smaller cross-sectional area than other portions at an intermediate portion in a longitudinal direction is used. The method for manufacturing a heat exchanger, wherein after performing the batch brazing, the side plate is cut and separated at a fracture inducing portion thereof.