JP2003075086A - Heat exchanger and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger, in which the front area is expanded to improve the performance without changing the installation size of an indoor unit, and without increasing material costs for a hair-pin pipe. SOLUTION: In the second expansion-flared head of the heat-exchanger pipe, an angle in the tapered end is determined from the conventional 10 deg.<=α<=15 deg. to 15 deg.<=β<=25 deg.. Thus, even when the hair-pin-pipe erection size from a side plate is reduced, buckling of the hair-pin pipe in the second pipe expansion- flaring work is prevented, and a stable work size can be obtained. Further, performance of the air conditioner is improved by extending the front area of the heat exchanger without changing the installation size in a conventional product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fin tube type heat exchanger and a method for manufacturing the same in an air conditioner such as a room air conditioner.

[0002]

2. Description of the Related Art A heat exchanger used in an air conditioner such as a room air conditioner has aluminum fins 1 having a plurality of holes formed at predetermined intervals, and a hairpin pipe 2 bent into a U shape in the holes. Insert it and fix the aluminum fin 1 and hairpin pipe 2 by expanding the mandrel, etc.
The hairpin pipe 2a protruding from the secondary expansion b and flare processing c is attached to the U-shaped bend pipe 3, which is conveyed on the conveyor and is automatically brazed by a side heating type automatic brazing device or the like. There is. In the method for manufacturing such a heat exchanger, JP-A-9-192759 and JP-A-10-192759 are used as means for improving the reliability of brazing of the U-bend pipe 3 by improving the dimensional accuracy of the flaring process c.
No. 292992 is disclosed.

[0003]

In the air conditioner, the heat exchanger tends to be large in size as a COP improvement measure due to recent energy saving regulations and the like. Especially in the indoor unit, the vertical dimension and the horizontal dimension of the product are changed from the installation dimension. Is limited, and in general, a multi-stage bending heat exchanger is the main method for expanding the front surface area. However, the expansion of the front surface area by the bending method of the heat exchanger has a problem that the number of bending steps increases and the productivity is deteriorated.

In consideration of the above problems, the present invention improves the shape of the secondary pipe expansion / flare processing head 5 for molding the portion to which the U-bend pipe 3 is attached, without changing the outer dimension of the indoor unit from the conventional one. Then, the w dimension between the plates is increased to provide a heat exchanger that contributes to performance improvement.

[0005]

In order to solve the above problems, the heat exchanger according to claim 1 of the present invention comprises a hairpin pipe 2
The material size of the product, the product size of the indoor unit, the secondary expansion part b for mounting the U-bend pipe 3 and the flare processing c size are not changed from the conventional size, and the startup size h from the side plate d is shortened from the conventional size. In addition, the front area of the heat exchanger is enlarged.

As a manufacturing method according to claim 2, the tip taper angle of the secondary pipe expanding / flaring head 5 is 10 ° ≦
By setting α ≦ 15 ° to 15 ≦ β ≦ 25 °, the tapered portion e of the secondary pipe expanding / flare processing head does not hit the side plate d of the heat exchanger during processing, and the hairpin pipe 2 during pipe expansion It is characterized by preventing deformation.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows the state of the secondary pipe expansion / flare processing of the heat exchanger of the present invention. As shown in FIG. 5, a general heat exchanger of an air conditioner has a plurality of laminated aluminum fins 1 and orthogonal U-shaped hairpin pipes 2 which are inserted into the through holes of the aluminum fins 1, First, the aluminum fin 1 and the hairpin pipe 2 are tightly fixed by the primary expansion. U bend pipe for circulating the opening as the next step
A secondary expansion b and a flare processing c are formed on the hairpin pipe 2a as a part for mounting 3.

At this time, the w dimension of the heat exchanger could not be increased due to the restriction of the installation dimension of the indoor unit, but according to the present invention, the rising dimension h from the side plate d of the heat exchanger is shortened. By this, U bend pipe 3
Since the dimension k up to the tip is not changed, the fan motor and the electric components can be mounted with the same dimensions as in the conventional case, and the outer dimension of the indoor unit can be made the same as in the conventional case.

However, if the stand-up dimension h from the side plate d is shortened, the conventional 2
When the secondary expansion / flare expansion head 4 was used, the taper angle of the tip was 10 ° ≦ α <15 °, so the tip e of the head hits the hole of the side plate d and buckles the hairpin pipe 2. There was a problem of deformation.

According to the method of manufacturing the heat exchanger of the present invention shown in FIG. 2, the taper angle β of the tip of the secondary pipe expansion / flare expansion head 5 is set to 15 ≦ β ≦ 25 ° from the experimental result shown in FIG. Due to the secondary pipe expansion / flare processing, the taper length of the head is 5
Since a can be shortened from the conventional 4a, even if the rise dimension h from the side plate d is shortened, the tapered portion e of the secondary pipe expanding / flaring head 5 does not come into contact with the side plate d and the seat of the hairpin pipe is It is possible to prevent bending and deformation and to perform stable dimension processing. As a result, the front surface area of the heat exchanger can be enlarged without changing the installation dimensions of the product, and the COP of the air conditioner can be improved.

At this time, since the tip taper e of the secondary pipe expanding / flaring head serves as a guide when inserting into the hairpin pipe 2, it becomes difficult to insert it into the hairpin pipe 2a if the angle is made too large. As shown in the experimental results shown in Fig. 3, the secondary expansion load increases and the hairpin pipe 2a
The taper angle β is 25 ° due to buckling and deformation of the part.
The following is desirable.

Further, according to the method of manufacturing the heat exchanger of the present invention, since only the shapes of the secondary expansion b and the flared portion c are changed, the material of the hairpin pipe 2 can be made without changing the material size of the hairpin pipe 2. There is an effect that the front surface area of the heat exchanger can be expanded and the performance can be improved without increasing the cost.

Even if the taper angle of the conventional secondary pipe expansion / flare pipe expansion head is shortened, the same effect can be obtained by shortening the U bend pipe fitting portion g and the flare processing dimension i. In this case, the U bend pipe 3 is brazed. At this time, if the U-bend pipe fitting part g is short, there is a risk of brazing, and if the flaring size i is short, there is a problem that the brazing material falls off from the flared part c, etc. Absent.

Further, when the pipe rising dimension from the side plate d is shortened, the flame of the burner is blocked by the side heating type automatic brazing device at the rising portion of the side plate d, which adversely affects brazing. However, it is possible to cope with this by shortening the rising dimension j of the side plate d accordingly.

[0016]

As described above, according to the heat exchanger of the present invention and the method for manufacturing the same, the plate-to-plate dimension w of the heat exchanger can be extended without changing the outside dimension of the indoor unit of the air conditioner from the conventional one. Further, the front surface area of the heat exchanger can be increased without increasing the material cost of the hairpin pipe 2, which can contribute to the improvement of COP.

[Brief description of drawings]

FIG. 1 is a state diagram of secondary tube expansion and flare processing of a heat exchanger.

FIG. 2 is a secondary expansion / flare processing state diagram of the present invention.

FIG. 3 is a result of a secondary pipe expanding processing experiment.

FIG. 4 is a conventional secondary tube / flare processing state diagram.

FIG. 5 is an external view of a general heat exchanger.

[Explanation of symbols]

1 ... Aluminum fin, 2 ... Hairpin pipe, 2a ... Hairpin pipe processing part, 3 ... U bend pipe, 4 ... Conventional secondary pipe expanding / flaring head, 4a ... Conventional secondary pipe expanding / flaring head Tapered part 5 ... Secondary pipe expanding / flare processing head of the present invention, 5a ... Secondary pipe expanding / flare processing head of the present invention Height of taper part, b ... U bend pipe insertion part, c
... flare processing part, d ... side plate of heat exchanger, e ...
Secondary pipe expansion / flare processing Head taper part, g ... U bend pipe fitting part, h ... Heat exchanger plate-to-plate dimension, i ... Flare processing dimension, j ... Side plate startup dimension, k ... Side plate to U bend Dimensions up to the tip of the pipe.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Isao Yokoshima             800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi             Hitachi Co., Ltd., Cooling & Heat Division

Claims (2)

[Claims] 1. An aluminum fin 1 comprising a plurality of laminated aluminum fins 1 and orthogonal U-shaped hairpin pipes 2 formed thereon.
In a heat exchanger such as a room air conditioner that is inserted into the through-hole of a room and formed by expansion, etc., it contributes to performance improvement by expanding the plate-to-plate dimension w without changing the external dimension of the indoor unit from the conventional one. And a heat exchanger. 2. An aluminum fin 1 comprising a plurality of laminated aluminum fins 1 and orthogonal U-shaped hairpin pipes 2 formed thereon.
In the secondary expansion b / flare processing c of the U bend pipe 3 insertion part of the heat exchanger formed by the primary expansion by being inserted into the through hole of the secondary expansion / flare head 5, the tip taper β of the secondary expansion / flare head 5
A method for manufacturing a heat exchanger, characterized in that the rising dimension h from the side plate d is shortened by setting the angle to 15 ° ≦ β ≦ 25 °.