JP3311001B2 - Method of manufacturing tubes for heat exchangers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger tube made of metal such as aluminum used for various heat exchangers such as condensers for air conditioners such as car coolers and room coolers. In this specification, "donation"
Is a mode to displace a part of the sheet material (20) in the width direction
Means bending by roll forming.
It is used as a term.

[0002]

2. Description of the Related Art For example, as a condenser for a car cooler, a so-called multi-flow type heat exchanger has recently been proposed as a device capable of realizing high heat exchange efficiency, low pressure loss and ultra-compactness. Tend to be used.

As shown in FIG. 8, the heat exchanger comprises a plurality of flat tubes (1) arranged in parallel.
The pair of left and right hollow headers (2) and (2) are connected to each other at both ends thereof in a communicating state, and the fins (3) are arranged in a gap between the tubes (1) and the inside of the header (2). At a predetermined position in the height direction, the refrigerant is partitioned by the partition (4), and the refrigerant flowing into the header (2) from the inlet pipe (5) flows through the group of tubes in a meandering manner and the outlet pipe (6). It is supposed to be leaked from.

Incidentally, in the flat tube (1) of such a condenser, particularly, since the refrigerant flowing inside is a high-pressure gas refrigerant, it is necessary to have a sufficient pressure resistance. As shown in Fig. (A), the upper flat tube wall (51) and the lower flat tube wall (52) are interconnected by an intermediate partition wall (54) inside the tube (53). Often done.

Conventionally, the production of a tube having such a partition has been carried out by a multi-hole extrusion technique using a hollow rod as is apparent from the tube structure in FIG.

[0006] However, in the production by extrusion, there is a limit in reducing the height (H) of the tube (53) to a certain value or more due to restrictions in the production technology. Therefore, when using the extruded tube (53), the resistance of the air flowing through the core cannot be reduced to a certain value or more, and the number of tubes within a certain core area is also limited, so that the contact area with the air cannot be increased to a certain value or more. As a result, there has been a limit in improving the heat exchange efficiency by devising the tube structure.

Recently, as shown in FIG. 9 (b), a strip-shaped sheet having a predetermined width is used to solve such a problem, and the sheet is formed into a U-shape at the center in the width direction. Fold it and weld the tip side edges together to produce a flat tube, a so-called flat ERW tube (61), and a corrugated plate (62) in this ERW tube (61).
There is also proposed a tube in which the corrugated plate (62) is brazed to the upper and lower tube walls (63) and (64) of the electric resistance welded tube (61) so as to improve the pressure resistance performance (particularly, Kaisho 62-
207572).

According to such a tube (65) made of an electric resistance welded tube, the height (H) of the tube (65) can be reduced by using an ultra-thin sheet as the band-shaped sheet. The above-mentioned disadvantages of the extrusion tube (53) can be solved, and the heat exchange efficiency of the heat exchanger can be further improved.
By the way, the height (H) of the tube (65) is made extremely low, such as about 1.5 to 1.7 mm, by using, for example, about 0.4 to 0.5 mm as the band-shaped sheet. Can be.

However, a corrugated sheet (62) is attached to the electric resistance welded pipe (61).
Is inserted into the pressure-resistant tube (65), which is a combination of a plurality of parts independent of each other. Generally, there is a grudge that causes various disadvantages in terms of productivity and the like. For example, not only does the cumbersome process of inserting the corrugated sheet (62) become necessary, but also the ERW pipe (61)
Is generally cut to a unit length, which is inferior in mass productivity.

Under such technical background, the following tube having excellent pressure resistance has been proposed (see Japanese Patent Application No. 2-122289 filed by the applicant of the present invention). As shown in FIG. 7, the tube (1) is formed by bending a band-shaped sheet, and by bending a part of the upper and lower tube walls (8) and (9) in a folded shape, the tube length is increased. It has a structure in which a bent ridge (12) is formed in the tube and protrudes in the direction extending in the direction, and the tip of the bent ridge (12) is integrated by brazing to the opposed flat tube walls (9) and (8).

According to the tube (1) having such a structure, the upper and lower tube walls (8) and (9) are connected by the bent ridges (12) so that they have excellent pressure resistance and are formed by bending a belt-shaped sheet. Thereby, the heat exchange performance can be improved by lowering the tube height (H), and further, the advantage in terms of productivity and the like due to the fact that the structure is not a combination structure of a plurality of parts can be exhibited.

Since the proposal of the tube structure, various methods for efficiently producing the tube (1), particularly a method for forming the bent ridge (12) most efficiently, have been studied and studied. .

[0013] In this background, the present invention can form the bent ridge, which extends in the longitudinal direction, in which a portion of the pipe wall in the circumferential direction is bent in a folded shape and protrudes in a rising shape, in the most efficient manner. Further, it is an object of the present invention to provide a reliable method capable of efficiently producing a heat exchanger tube having such bent ridges.

[0014]

In order to achieve the above object, the present invention has a joint extending in a longitudinal direction at any position in a circumferential direction of a tube wall, and a part of the joint in a circumferential direction of the tube wall. Is a method of manufacturing a tube for a heat exchanger having a bent ridge that is bent in a folded shape by bending by roll forming, protruded in a rising shape, and extended in a length direction, wherein a pair of the bent ridges is formed. After forming one of the rising portions of the material into a vertical rising shape first, bend a part of the material to form a folded portion
To form the other rising part, and the other rising part
Part in the direction of overlapping the one rising part.
The gist of the present invention is a method for manufacturing a tube for a heat exchanger, wherein the bent ridges are formed by bringing both rising portions into a bent and overlapped state.

[0015]

According to the above-mentioned method, a folded and bent protruding shape is formed simply by passing through a roll forming machine composed of roll rows.

[0016]

Next, an embodiment in which the present invention is applied to a method for manufacturing a pressure resistant tube (1) for a multi-flow type condenser as shown in FIG. 7 will be described.

[0017] The production target serving tube of the present invention method, manufacturing such a tube heat exchanger tip free bending rib, short, a part of the tube wall in the circumferential direction is bent into the folded shape The present invention can be widely applied to the manufacture of various heat exchanger tubes having bent ridges extending in the length direction protruding in a rising shape.

In the heat exchanger tube (1) shown in FIG. 7, (8) and (9) are upper and lower flat tube walls, (1)
0) is a U-shaped pipe wall, (11) is a joint, and (12) is a bent ridge.

The upper and lower planar tube walls (8) and (9) are arranged parallel to each other at a predetermined interval, and one side edge thereof is integrally connected in a metallographic manner by a U-shaped wall (10). It has been done. That is, the flat tube walls (8) and (9) and the U-shaped tube wall (10) are integrally formed by folding a band-shaped sheet material having a predetermined width into a U-shape at the center in the width direction. ing. And both flat tube walls (8)
(9) The other side edge is bent into an inwardly curved shape, and the front end thereof is formed into a bent shape as the abutting portions (14, 15), and the abutting portions (14, (15) )
Are brought into contact with each other. The butted portions (14) and (15) are joined and integrated by brazing to form an internally sealed flat tube.

The bent ridges (12) are formed such that a part of the upper and lower planar tube walls (8) and (9) in the circumferential direction is bent in a folded manner so that the inner surfaces of the planar tube walls (8) and (9) are bent. A flat tube wall (9) which is vertically raised inside the pipe and extends in the length direction of the tube, and whose ends in the rising direction face each other.
The inner surface of (8) is joined and integrated by brazing.

In the method of this embodiment, the tube (1) having the above structure is manufactured as follows.

That is, a strip-shaped sheet material (20) made of an aluminum brazing sheet having a predetermined width is used as a forming material. The brazing sheet uses a brazing material clad on both sides. In addition, this material (20)
Has a thickness corresponding to the thickness of the tube wall of the tube (1) to be manufactured.

As an apparatus for forming the bent ridge (12), a roll forming machine (22) in which a plurality of pairs of upper and lower forming rolls (23) and (24) are arranged in series is used.

The gap between the upper and lower rolls (23) and (24) of each set in the roll forming machine (22) is adjusted so that a proper bending is applied to the material (20) at the forming location. 20) The thickness is set to be approximately the same as
In other parts, the thickness of the molding material (20) is generally set to be substantially the same as or larger than that of the molding material (20) so that the sheet material (20) can be freely displaced in the width direction during molding. In other words, the sheet material (2
Bending is performed so that no elongation in the width direction occurs in 0).

The upper and lower rolls (23) and (24) are formed with annular projections and recesses (23a) and (24a) for male and female, respectively. The gap shape is changed stepwise from the rolls (23) (24) on the sheet material insertion side to the rolls (23) (24) on the exit side according to a predetermined mode according to the progress of molding. It is being changed.

Although not shown, a roll forming machine for forming the butted portions (14) and (15) and a U-shaped pipe wall (10) are provided at the outlet side of the bent ridge forming roll forming machine (22). ) And a roll forming machine for forming the same are sequentially and sequentially arranged in series.

In manufacturing the tube (1), first,
The strip-shaped sheet material (20) is passed through the roll forming machine (22) or the like to form a tube-shaped body before brazing. This forming step includes a step of forming the bent ridge (12) and a step of forming the butted portion (14) (1).
5) and a step of forming a U-shaped pipe wall (10).

The step of forming the bent ridge (12) comprises a combination of simultaneously forming two bent ridges (12). That is, as shown in FIG. 2 (g), two adjacent bent ridges (12), (12) are formed, and then, as shown in FIG. Two bent ridges (12)
Step (12) is performed sequentially.

Simultaneous molding of two adjacent bent ridges (12) and (12) is performed through a molding process as shown in FIGS. 1 (a) and 2 (g). That is, first,
As shown in FIG. 1 (c), while going through the material feeding process as shown in FIG. 1 (b), both bent ridges (12)
Rising part (12b) (12c) on the opposite side of (12)
Is formed into a vertically standing shape . Next, FIG. 2 (d)
As shown in the opposite side rising part (12a)
The folds (26) and (26) are formed to form ( 12d ), and the folds (26) and (26) are formed to a right angle as shown in FIG. After a while, the second
As shown in Figure (f), the adjacent rising portions (12
a) The parts (12b) and (12c) and (12d) are brought closer to each other, and then they are bent and overlapped as shown in FIG. 2 (g). As described above, two adjacent bent ridges (12) and (12) are formed.

Next, FIGS. 3 (h) to 4 (l)
As shown in (2), the next two adjacent bent ridges (12) and (12) are formed in the same manner as described above. It should be noted that the already formed bent ridge (12) due to the sheet retracting operation that occurs during this molding
In order not to hinder the free displacement in the width direction of (12), the upper roll (23) is at a predetermined distance from the lower roll (24) in the area where the formed bent ridges (12) and (12) are present. It is formed so as to be greatly separated only by a large distance.

The formed sheet in which the required number of bent ridges (12) have been formed by repeating the above-described molding in units of two pieces is then sent continuously as it is into a butting portion forming roll forming machine. 5 As shown in FIG. 5A, the butted portions (14) and (15) are formed. The structure of the abutting portions (14) and (15) may be of a bent and folded shape as shown in FIG. (A), or the joint area may be reduced as shown in FIG. In order to secure a wide space, the upper and lower flat tube walls (8) and (9) may be made to project inward in parallel with each other, or other butting structures may be employed.

Further, the formed sheet is continuously fed as it is into a roll forming machine for forming a U-shaped tube wall, and the U-shaped tube wall (10) is formed as shown in FIG. From the outlet side of the forming machine, a tube formed body having a predetermined tube shape before brazing and having a bent-formed structure shown in FIG. 7 is sent out.

Then, brazing such as in-furnace brazing is performed on the tube formed body formed as described above. As a result, the tips of the bent ridges (12) are joined to the upper and lower flat tube walls (9) and (8), and the butted portions (14) and (15) are combined together. Including each other,
It is brazed together and manufactured into a perforated flat tube (1) as shown in FIG.

In the above embodiment, the case where the bending ridges (12) are formed in units of two has been described. However, the bending ridges (12) may be formed in units of one unit or a combination of one unit and two units. You may. Further, in the above-described embodiment, the butting portions (14) and (15) are joined by brazing, but this portion is subjected to ERW welding at a stage before the above-mentioned brazing to be joined. May be performed.

According to the above description, since the method for manufacturing a tube for a heat exchanger of the present invention is such that the bent and protruding shape is formed by bending by roll forming, the bent and bent shape is simply passed through a roll forming machine. The ridges are formed, and the bent ridges can be formed efficiently, so that efficient production of a tube having such bent ridges can be realized. Also, after forming one of the pair of rising portions constituting the bent ridge into a vertical rising shape first, a part of the material is bent.
To form the fold, so that the other
And forming the other rising portion with the one rising portion.
This is achieved by moving in the direction to overlap the beam
Since the two raised portions are bent and overlapped to form a bent ridge, the wall thickness of the tube wall is not affected by elongation, and the strength as designed can be secured, and the bent ridge is formed. And the distance between the bent ridges can be precisely controlled as designed, and a high-quality tube can be provided.

[Brief description of the drawings]

FIGS. 1A to 1C are cross-sectional views of a molding material showing a state in which a bent ridge is being formed.

FIGS. 2 (d) to 2 (g) are cross-sectional views of a forming material showing a state in which a bent ridge is being formed.

FIGS. 3H and 3I are cross-sectional views of a molding material showing a state in which a bent ridge is being formed.

FIGS. 4 (a) and 4 (b) are cross-sectional views of a forming material showing a state in which a bent ridge is being formed.

FIG. 5A is a cross-sectional view of a butted portion after molding, and FIG. 5B is a cross-sectional view of a butted portion according to a modification.

FIG. 6 is a cross-sectional view of a material showing a state in which a U-shaped tube wall is being formed.

FIG. 7 is a sectional view of a tube to be manufactured according to the present invention.

FIG. 8A is an overall front view of the heat exchanger, and FIG. 8B is a plan view thereof.

FIG. 9A is a sectional view of a conventional tube, and FIG.
FIG. 4 is a sectional view of another conventional tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tube 11 ... Joint part 12 ... Bending ridge 22 ... Roll forming machine 23, 24 ... Forming roll

Continuation of the front page (56) References JP-A-56-71520 (JP, A) JP-A-5-164484 (JP, A) JP-A-63-242432 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B21D 53/06 F28F 1/02 B21C 37/15 B21D 53/04

Claims (1)

(57) [Claims] The present invention has a joining portion extending in a longitudinal direction at any position in a circumferential direction of a tube wall, and a part of the tube wall in a circumferential direction is bent in a folded shape by a bending process by roll forming. A method for manufacturing a tube for a heat exchanger having a bent ridge protruding in a rising direction and extending in the length direction, wherein one of the rising portions constituting the bent ridge is first raised. After molding in a vertical rising shape,
By bending a part of the material to form a fold
The other rising part is formed, and the other rising part is formed.
In the direction of overlapping with the one rising part.
A method for manufacturing a tube for a heat exchanger, wherein the raised portions are bent and overlapped to form the bent ridge.