JP2002224756A - Heat exchanger bending method - Google Patents

Abstract

(57) [Summary] [Problem] Although the front area of an outdoor unit heat exchanger for an air conditioner has been expanded to improve the performance, it is bent in a predetermined space to make the product compact. Need to be stored. At this time, a need arises for a method of bending the fins and heat transfer tubes of the heat exchanger without deforming them. In a heat exchanger having a small bending start-up dimension, a fin slide plate (a) is provided on a bending mold (11) in contact with the inside of a fin, and a fin slide plate (a) is further provided. In the case where the exchangers 1c and 1d are simultaneously bent, the fin slide plate b is provided between the upper fin and the lower fin so that the fin can be bent without deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a finned heat exchanger used in an air conditioner and the like and a bending method.

[0002]

2. Description of the Related Art An outdoor unit such as a room air conditioner comprises a refrigeration cycle including a compressor 5, a blower 4, and a heat exchanger in a box 3 made of steel plate or resin. The heat exchanger used has a large front area of the heat exchanger as a measure for improving the performance, and as shown in FIG.
The heat exchanger is used to be bent and housed in the box body 3 like the heat exchanger 1a and the heat exchanger 1b.

[0003] The heat exchanger 1b of the room air conditioner outdoor unit is connected to the U
When bent into a shape and stored in the box 3, a space for disposing the refrigerant pipe 6 of the heat exchanger in the machine room including the compressor 5 is required. Must be small. Thereby, the bending property of the heat exchanger is remarkably deteriorated, and as shown in FIG. 9, deformation A of the plate-like fin 7 having a thickness of about 0.1 mm and collapse of the heat transfer tube 8 having a thickness of about 0.3 mm occur during bending. Affects the heat exchange performance. Japanese Patent Application Laid-Open No. Hei 10-85879 shown in FIG. 2 shows a method of bending a finned heat exchanger of this type. An example of using a stress-dispersing buffer 30 to prevent fin deformation during bending is described. However, in this case, there remains a problem in handling of the stress-dispersing buffer 30, which is a spring steel plate having a thickness of 1 mm, and a technical problem of simultaneously bending two types of heat exchangers.

[0004]

In the heat exchanger of the air conditioner, the deformation of the fins and the deformation of the heat transfer tube greatly affect the heat exchange performance.
There arises a need for a highly productive bending method in which two types of heat exchangers having different length dimensions are used in the same facility.

According to the present invention, the performance of a heat exchanger is improved by simultaneously bending two types of heat exchangers 1c and 1d having different lengths L2 and L3 without causing deformation of fins and heat transfer tubes. The purpose is to secure and improve productivity.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, a first aspect of the present invention is to form a heat exchanger for bending two types of heat exchangers simultaneously without deforming fins and pipes. The method is characterized in that even a heat exchanger having a small bending start-up dimension L can be bent with high productivity by preventing deformation of fins and heat transfer tubes.

According to the first aspect of the invention, the dimensional accuracy of the heat exchanger clamp portion is improved to prevent the clamp portion from slipping, and at the same time, the parallelism of the height dimension H is improved so that even in the case of repeated processing, it is stable. Bending becomes possible.

In the second invention, the fin slide plates a and b
Is characterized by using a steel plate having a low frictional resistance, such as a spring steel plate or a stainless steel plate having a thickness of 0.1 to 0.3 mm.

In the third invention, the step S between the bending wing table 10 and the slide table 12 is 3 ≦ S ≦ 1
It is characterized by being 0 mm. In addition, by combining with the fin slide plate of the first aspect, an unreasonable load is not applied to the fin or the heat transfer tube, and it is possible to prevent the deformation of the fin or the heat transfer tube.

[0010]

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

FIGS. 1 (A) and 1 (B) are component arrangement diagrams of a home air conditioner outdoor unit provided with a heat exchanger of the present invention. The refrigeration cycle includes a compressor 5, heat exchangers 1a and 1b, refrigeration cycle piping components 6, and the like. The heat exchanger 1a is bent into an L shape in order to improve the performance, and the front area is enlarged. When the heat exchanger 1b is bent into a U shape and housed in the box body 3 as a means for further enlarging the front surface area, the heat exchanger 1b is provided with a space for piping parts 6 for connecting the compressor 5 and the heat exchanger. It is necessary to reduce the bending up dimension L.

In the case of the two types of heat exchangers 1c and 1d, as shown in FIG. 8, since the longitudinal dimensions L2 and L3 are different, the plate fins are separately laminated on the heat exchanger 1c and the heat exchanger 1d. Then, copper heat transfer tubes 8 having different longitudinal dimensions are inserted into the through holes of the plate-like fins 7 in a cross shape, and the fins and the heat transfer tubes are brought into close contact with each other by mandrel mechanical expansion or the like.
Next, the U-bend pipe 9 is inserted and brazed by the next expansion 8a. At this time, the end plates of the two types of heat exchangers are
By fitting and fixing as shown in 20c, the brazing of the U-bend pipe 9 to different heat exchangers can be joined in the same process.

After configuring the heat exchanger in this way,
As shown in FIG. 3, bending is performed in steps a) to d).
In the step a), the end plate 20a is attached to a positioning pin installed on the bending wing table 10 to determine the bending position of the heat exchanger, and the bending position is determined. Clamp the fins on the end plate side. At this time, even in the case where the clamp portion size G of the heat exchanger is small, in order to obtain the clamp height H with high accuracy, two mechanical stoppers 15 are provided in the clamp portion to determine the height size H, thereby performing repetitive machining. Also, there is no change in the positional accuracy, and by providing two locations, the parallelism of the clamp portion is improved, slippage of the clamp portion can be prevented, and variation in bending can be reduced (first example).
Invention).

A bending die 11 having a clamp mechanism has a fin slide plate a
Is installed so as not to get on the end plate 20b. Also, by performing bending between the heat exchangers 1c and 1d via the fin slide plate b, deformation due to buffering between the fins can be prevented.

FIG. 7 shows a conventional heat exchanger at the beginning of bending. At this time, if there is no step between the bending wing table 10 and the slide table 12, the bending die 1
Since the one surface and the fins are in direct contact with each other and there is no escape portion for the heat exchanger, a reaction force of a force c for forcibly extending the heat transfer tube 8 is applied between the bending mold 11 and the fin 7 in contact. For this reason, the fins 7 having a plate thickness of about 0.1 mm and having a low rigidity are shown in FIG.
Problems such as deformation as in part A and buckling of the inside of the heat transfer tube 8 occur.

In order to prevent the deformation of the fins and the buckling of the heat transfer tube, the heat exchangers 1c and 1d can be separately bent to reduce the load and prevent the deformation. There is a problem that the number of steps is increased and productivity is deteriorated.

FIG. 5 shows a clamped state of the heat exchanger according to the present invention, and FIG. 6 shows a state at the beginning of bending of the heat exchanger according to the present invention. Bending wing table 10 and slide table 12
Is set to 3 ≦ S ≦ 10 mm (third invention), and between the bending mold 11 and the inside of the heat exchanger 1d and between the outside of the heat exchanger 1d and the inside of 1c, respectively. A 0.3 mm fin slide plate a and a fin slide plate b are provided.
Invention). At this time, since the fin slide plate a is fixedly installed on the bending mold 11, it is not necessary to set the fin slide plate a for each processing, so that it can be used continuously.

In the present invention, the bending is performed while pressing the heat exchanger against the bending die 11, and the fin slide plate a and the heat exchanger 1d are pressed while the heat exchanger is pressed against the bending die 11.
Slip occurs between the fins. In addition, the fin slide plate b generates a slip between the outer fins of the heat exchanger 1d and the inner fins 1c, and the heat exchangers 1d, 1c
The heat transfer tube 8 is bent on the basis of the central axis 8b, and the heat transfer tube material can shrink inward in the direction of arrow d and expand outside, so that no excessive load is applied to the heat transfer tube, and the fin 7 can be deformed or transferred. The heat tube 8 can be bent without deformation or buckling.

Next, the results of an experiment in which two heat exchangers each having a fin plate thickness of 0.105 mm, a fin width of 17.3 mm, a fin pitch of 1.5 mm, and a heat transfer tube outer diameter of 8 mm are stacked and bent to an inner radius of 60 mm will be described. I do.

First, in the case where the fin slide plate b is installed between the heat exchanger 1c and the heat exchanger 1d and when it is not installed, the bending radius R between the outside of the 1d fin and the inside of the 1c fin is set.
Looking at the fin deformation of the portion, when the fin slide plate b was not installed, the fin was greatly deformed, whereas when the fin slide plate b was interposed, the fin could be bent without deformation of the fin.

Next, the fin slide plate a
Of the bending wing table 10 and the slide table 12, the bending experiment was performed by changing the conditions. As a result, when the fin slide plate a was not installed, the heat exchanger was bent with the bending wing table 10 at the beginning of bending. The deformation A of the fin in the portion in contact with the exchanger 1c and the buckling of the heat transfer tube 8 occurred.

When the fin slide plate a is set as a spring steel plate or a stainless steel plate 0.2 mm,
When the step S of the slide table 12 was not provided, deformation A inside the fin in contact with the bending die 11 was observed.
When the step was lowered by 0 mm, no deformation of the fin was observed, and good results were obtained.

As described above, the fin slide plates a and b are made of a spring steel plate or a stainless steel plate and have a thickness of 0.1 to 0.3 mm.
Under the condition that the step S between the bending wing table 10 and the slide table 12 is 3 ≦ S ≦ 10 mm, the fins and the heat transfer tubes can be bent without being deformed.

[0024]

As described above, the following effects can be obtained by the present invention.

According to the first aspect of the present invention, even in a heat exchanger having a small clamp dimension G, the clamp height H at the time of bending can be controlled with high accuracy, and slip of the clamp portion can be prevented to achieve stable heat exchange. The vessel can be bent.

According to the second aspect of the invention, even when the two types of heat exchangers 1c and 1d are bent, the fin slide plate a is disposed on the bending mold 11, and the two types of heat exchangers 1c and 1d are further bent.
By disposing the fin slide plate b between them and bending the heat exchanger, the bending can be performed on the same equipment without deforming the fins and the heat transfer tubes of the U-shaped heat exchangers 1c and 1d.

According to the third aspect, since no excessive load is applied to the heat transfer tube at the time of bending the heat exchanger, the bending can be performed without deformation of the fins and buckling of the heat transfer tube.

[Brief description of the drawings]

FIG. 1 is a component layout diagram of an air conditioner outdoor unit.

FIG. 2 is a diagram of a stress dispersion buffer described in an example of Japanese Utility Model Application Laid-Open No. 10-85879.

FIG. 3 is a view showing a bending process of a U-shaped heat exchanger.

FIG. 4 is an enlarged view of a fitting portion of two types of heat exchangers.

FIG. 5 is a sectional view showing a heat exchanger clamped state of the present invention.

FIG. 6 is a cross-sectional view showing a state where bending of the heat exchanger according to the present invention is started.

FIG. 7 is a cross-sectional view showing a state where bending of a conventional heat exchanger is started.

FIG. 8 is an external view showing two types of heat exchangers.

FIG. 9 is a cross-sectional view showing a deformed state of the heat exchanger fin.

[Explanation of symbols]

1a L-shaped heat exchanger, 1b U-shaped heat exchanger, 3 box,
4 ... Blower, 5 ... Compressor, 6 ... Piping parts, 7 ... Plate aluminum fin, 8 ... Heat transfer tube, 8a ... Heat transfer tube secondary expansion section, 8b
... Bending central axis of heat transfer tube, 9 ... U-bend pipe, 10 ... Wing table, 11 ... Bending mold, 12 ... Slide table, a ... Fin slide plate, b ... Fin slide plate, c
... elongation of the heat transfer tube, d ... moving direction of the heat transfer tube material, 15 ... stopper, 20a ... end plate of heat exchanger 1c, 2
0b: End plate of heat exchanger 1d, 20c: End plate fitting part, 30: Buffer for stress dispersion, A: Deformed part of aluminum fin, G: Clamp of heat exchanger, H: Clamp height of heat exchanger, L … Start-up dimension of heat exchanger bending part, S
… Steps between the wing table and slide table.

Continued on the front page (72) Inventor: Seiichi Kodaira 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Inside Tochigi Technology Co., Ltd. (72) Inventor Isao Yokoshima 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi F-term in Hitachi Tochigi Technology Co., Ltd. (reference) 3L065 AA09 4E063 AA04 AA19 BC06 CA03 GA01 JA02 MA02 MA17

Claims (1)

[Claims] 1. A method for bending two types of heat exchangers, wherein a copper tube for a heat exchanger made of copper used in an air conditioner and the like and a plurality of plate-like aluminum fins are brought into close contact by expansion or the like. A bending method wherein two height-adjusting stoppers are provided in a clamp portion of an exchanger, and a clamp of a heat exchanger is made parallel to prevent slipping of the clamp portion.