JPH05164484A - Heat exchanger tube and manufacture thereof - Google Patents

Abstract

PURPOSE:To enhance heat exchange efficiency and pressure resistance by molding integrally a projection on a plane tube wall longitudinally and welding integrally the projection with a projection formed on the inner surface of a plane tube wall on the other side in the title eclipse-shaped tube in its cross section for a car cooler or the like. CONSTITUTION:A partitioning projection 12 is integrally installed to the inner surface of an upper plane tube wall 8 and a lower plane tube wall 9 which form a heat exchanger tube 1 which is eclipse-shaped in its cross section. When the upper and lower plane tube walls 8 and 9 are bent with a U-shaped tube wall 10 as a fulcrum and but-welded with projected parts 14 and 15, the tip of the partitioning projection 12 is arranged to come in contact with the inner surfaces of the plane tube walls 8 and 9 on the opposite side respectively. Under this construction, each partitioning projection 12 is brazed with the inner surface of the plane tube walls 8 and 9 on the opposite side where the projections 14 and 15 are brazed, thereby forming the tube 1. This construction makes it possible to enhance the pressure resistance and reduce the height H of the tube 1 so as to improve the heat exchange efficiency, and what is more, manufacture the tubes with more enhanced productivity.

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 in various heat exchangers such as condensers for air conditioners such as car coolers and room coolers, and a manufacturing method thereof.

[0002]

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

This heat exchanger has a plurality of flat tubes (1) arranged in parallel as shown in FIG.
A pair of left and right hollow headers (2) and (2) are connected to both ends of the tube so that the fins (3) are arranged in the gap between the tubes (1) and the inside of the header (2) is The refrigerant is divided by the partition (4) at a predetermined position in the height direction, and the refrigerant flowing from the inlet pipe (5) into the header (2) circulates in the tube group in a meandering manner and the outlet pipe (6). It is supposed to be leaked from.

By the way, in the flat tube (1) of such a condenser, in particular, since the refrigerant flowing inside is a high-pressure gas refrigerant, it is necessary to have sufficient pressure resistance. As shown in Fig. (A), the upper flat tube wall (51) and the lower flat tube wall (52) are connected to each other by the intermediate partition wall (54) inside the tube (53). Is often done.

Conventionally, the production of such a partitioned tube has been carried out by using a porous extrusion technique using a holloidice, as is apparent from the tube structure shown in FIG.

However, in the production by extrusion, there is a limit in reducing the height (H) of the tube (53) beyond a certain level due to the limitation of 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 level or more, and the number of tubes within a certain core area is also limited, and the contact area with air cannot be increased to a certain amount or more. As a result, there has been a limit in improving the heat exchange efficiency by devising the tube structure.

In response to such a problem, recently, as shown in FIG. 6 (b), a strip-shaped sheet having a predetermined width is used, and this is formed into a U-shape at the central portion in the width direction. The flat pipe, so-called flat electric resistance welded pipe (61) is manufactured by folding back and welding the edge portions on the front end side, and the corrugated plate (62) is inside the electric resistance welded pipe (61).
A tube with improved pressure resistance performance is also proposed by inserting a corrugated plate (62) and brazing the corrugated plate (62) to the upper and lower pipe walls (63) (64) of the electric resistance welded pipe (61). Kaisho 62-
207572).

According to such a so-called ERW tube (65), the height (H) of the tube (65) can be lowered by using an ultrathin sheet as the strip plate sheet. The above drawbacks of the extruded tube (53) can be eliminated, and the heat exchange efficiency of the heat exchanger can be further improved.
Incidentally, by using a strip plate sheet having a thickness of, for example, about 0.4 to 0.5 mm, the height (H) of the tube (65) is manufactured to a very low height of about 1.5 to 1.7 mm. You can

However, the corrugated plate (62) is attached to the electric resistance welded pipe (61).
The structure relating to the combination of a plurality of independent parts, which are inserted into the pressure resistant tube (65) to form a pressure resistant tube (65), has a general grudge that causes various disadvantages in terms of productivity and the like. For example, not only the troublesome process of inserting the corrugated plate (62) is required, but also when the corrugated plate (62) is inserted, the electric resistance welded pipe (6
Since 1) had to be cut to a standard length, it was inferior in mass productivity.

The present invention has been made in view of the above conventional problems, and the first invention can reduce the height to improve the heat exchange efficiency of the heat exchanger. At the same time, it is an object of the present invention to provide a heat exchanger tube having a structure that is excellent in pressure resistance and that has a structure in which a combination structure of a plurality of parts can be eliminated to increase the advantages in terms of productivity and the like.

The second aspect of the present invention is capable of producing a heat exchanger tube, which is provided in an upright state in such a manner that a single projection is integrally formed on the tube wall and extends in the longitudinal direction, with high productivity. The purpose is to provide a possible method.

[0012]

In the above object, the first
The invention of (1) is a tube for a heat exchanger having an oval cross section having a joint extending in the longitudinal direction at any position in the circumferential direction of the tube wall, the tube being integrally formed with the inner surface of one flat tube wall. A protrusion in which one protrusion is provided in an upright state in a manner extending in the longitudinal direction, and the protrusion is formed corresponding to the inner surface of the other flat tube wall or the inner surface of the other flat tube wall. The gist is a tube for a heat exchanger, which is characterized in that the tube is joined and integrated with the section.

According to a second aspect of the present invention, there is provided a joint portion extending in the lengthwise direction at any position in the circumferential direction of the pipe wall, and the pipe wall is integrally provided with a single protrusion. A method for manufacturing a heat exchanger tube that is provided in an upright state in a manner extending in the vertical direction, wherein a tube forming material that is thicker than the tube wall of the tube to be manufactured is used Using a rolling roll having an annular concave portion for forming a protrusion in its part, the raw material is rolled in the thickness direction by the rolling roll to reduce the wall thickness to the thickness of the tube wall, and by this thinning, the concave portion of the roll The gist is a method of manufacturing a heat exchanger tube, characterized in that the protrusion is formed by bulging by using the roll recessed portion with a metal removed to the side.

[0014]

In the tube having the above structure, the two flat tube walls are connected to each other by the projection, so that high pressure resistance is secured.

Further, since the tube of the present invention has a joint portion extending in the longitudinal direction at any position in the circumferential direction, the tube of the present invention is involved in pipe bending forming from a raw material, so that the wall thickness of the pipe wall is extruded. The heat exchange efficiency of the heat exchanger can be improved because the tube height can be made much thinner than that in the case described above.

Moreover, the projection is formed integrally with the inner surface of one of the flat tube walls, and the projection is originally formed integrally with the flat tube wall. By virtue of this, the advantage in terms of productivity and the like is exhibited as compared with the structure using a connecting member such as an independent corrugated plate different from the tube.

Further, in the above method, the tube forming material having a wall thickness larger than that of the tube wall of the tube is simply passed through the rolling roll, and by the action of the annular recess of the rolling roll, the projection of one piece is integrated with the tube wall. Is molded.

[0018]

EXAMPLE Next, an example in which the present invention is applied to a multi-flow type condenser tube will be described. Needless to say, the tube of the present invention is widely applied as a tube in heat exchangers of various types and various applications.

In the heat exchanger tube (1) having an oval cross section according to the present invention shown in FIG. 3, (8) and (9)
Are upper and lower flat pipe walls, (10) is a U-shaped pipe wall, (11) is a joint, and (12) is a partitioning projection.

The upper and lower flat tube walls (8) and (9) are arranged in parallel with each other at a predetermined interval, and one side edge thereof is metallically connected integrally by the U-shaped tube 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 strip-shaped sheet material having a predetermined width into a U-shape at the central portion in the width direction. ing. And both flat tube walls (8)
(9) The other side edge portion is bent inwardly, and its tip end is formed into a bent back shape as a butted portion (14) (15), and the butted portion (14) (15) is formed. )
The tip ends of the are abutted against each other. And
Both butted portions (14, 15) are joined and integrated by brazing to form an internally sealed flat tube.

The partitioning projection (12) is a single piece, and one end of the partitioning projection (12) is provided integrally with the inner surface of one of the flat tube walls (8) and (9), that is, as a metallic structure. , And is joined perpendicularly to the flat tube walls (8) and (9), and is joined and integrated by brazing in a state where its tip end is in contact with the other flat tube walls (9) and (8). Has been done.

In the production of the heat exchanger tube (1), a band plate material (20) of a predetermined width made of an aluminum brazing sheet is used as a molding material. As the brazing sheet, a brazing material clad on both sides is used. Further, the wall thickness of the strip plate material (20) is set to a predetermined thickness that is thicker than the tube wall of the tube (1) to be manufactured.

Further, as a device for molding the protrusion (12),
As shown in Fig. 1, a pair of upper and lower rolling rolls (23)
A rolling mill (22) in which a plurality of sets (24) are arranged in series is used. The gap between the upper and lower rolls (23) and (24) of each set in this rolling mill (22) is gradually narrower from the insertion side of the material (20) toward the ejection side than the thickness of the material (20). It is set so that it becomes a material (20)
Is being rolled and thinned. In addition, the upper roll (23) has an annular recess (23a) for forming a protrusion.
Is formed, and the width is gradually narrowed and deepened from the insertion side of the material (20) toward the exit side.

The projection (12) of the tube (1) is formed by passing the strip material (20) through the rolling mill (22). That is, as shown in FIG.
The strip plate material (20) passed between the first rolling rolls (23) and (24) gradually decreases its wall thickness by the rolling action, as shown in (b) to (e) of the same figure. And finally,
The thickness of the tube (1) to be manufactured is reduced to the thickness of the tube wall. Then, in the process of thinning, the metal removed by the rolling action is the annular recess (23) of the upper roll (23).
By the action of a), it is moved toward the annular recess (23a) side, and the raised portion (25) is formed there. Then, following the change in the shape of the annular recess (23a), the partition projection (12) is gradually formed. As a result, as shown in FIG. 1 (e), the material (20) is molded into an intermediate molded product (27) having a partitioning protrusion (12) of a predetermined shape that rises integrally with one piece. ..

Then, as shown in FIG. 2 (f-1), both side edges of the intermediate molded product (27) in the width direction are bent in a folded state to form butt portions (14) (15). .. It should be noted that both side edge butting portions (14) (1) of the intermediate molded product (27)
As shown in (f-2) of the same figure, 5) may be formed in such a manner that it is inwardly projected in parallel with the flat tube walls (8) and (9) in order to secure a wide bonding area. Good.

Thereafter, the intermediate molded product (27) is folded back into a curved shape at the center position in the width direction as shown in FIG. 2 (g), and as shown in FIG.
A U-shaped tube wall (10) is formed, and a butted portion (1
4) Put the (15) parts against each other, and the protrusion (14)
Is molded in a state in which the tip end of is contacted with the inner surface of the other flat tube wall (9) (8). The butting portions (14) and (15) and the U-shaped tube wall (10) are continuously formed by continuously feeding them to a roll forming machine or the like that is continuously provided behind the rolling mill (22).

After that, the molded body is placed in a furnace, and the butted portions (14) and (14) and the tips of the projected portions (12) and the inner surfaces of the flat tube walls (9) and (8) are put together. Joining is integrated by brazing. Note that this brazing is generally performed together with brazing between the constituent parts of the heat exchanger assembly in which the tube molded body is combined with the header (2) and the like. The tube (1) is manufactured as described above.

In the tube (1), since the flat tube walls (8) and (9) are connected to each other by the protrusions (12), the pressure resistance is excellent, and the heat exchange medium flowing inside has a high pressure. Even if it is such a medium, excellent pressure resistance performance can be exhibited. Moreover, since it is folded back at the U-shaped wall (10) and the abutting portions (14) and (15) are joined together,
Tube (1) by reducing the wall thickness of the flat tube wall (8) (9)
The height of the heat exchanger can be reduced, and the heat exchange efficiency of the heat exchanger can be improved.

In addition, the projection (12) is integrally formed with the inner surface of one of the flat tube walls (8) and (9) so that the projection (12) is essentially formed. Since it is formed integrally with the flat tube walls (8) and (9), the upper and lower flat tube walls are connected to each other by using an independent member different from the tube, for example, a corrugated plate (62). As compared with the structure in which the pressure resistance is improved, various advantages can be exhibited in terms of productivity and the like.

In the method of the above embodiment, the flat tube wall (8) can be obtained by simply passing the strip material (20) thicker than the tube wall of the tube (1) through the rolling rolls (23) (24). (9)
A single projection (12) is formed integrally with the inner surface of the above, and the projection (12) having such a configuration can be easily and efficiently formed. In addition, since it is made to continuously pass through a roll forming machine to form a tube molded body before brazing, it is possible to produce a tube (1) having excellent pressure resistance and a low height as compared with the conventional one. Can be performed efficiently.

The tube to be manufactured in the method of the present invention is limited to the tube having the structure in which the tip of the projection (12) is joined to the other flat tube wall (9) (8) as in the above embodiment. It is not limited to this, and may be a tube or the like having a projection with a free tip. Further, in the above-mentioned embodiment, the butting portions (14) and (15) are joined by brazing, but this portion is joined by electric resistance welding before the above brazing. It may be done.

[0032]

As described above, since the heat exchanger tube of the present invention has the flat tube walls connected to each other by the protrusions, it has excellent pressure resistance and the heat exchange medium flowing inside has a high pressure. Even in such a case, excellent pressure resistance performance can be exhibited. Moreover, since the tube of the present invention has a joint portion extending in the lengthwise direction at any position in the circumferential direction of the tube wall, the tube of the present invention is subjected to bending from the tube forming material. Can be made thinner,
As a result, the tube height can be reduced, and the heat exchange efficiency of the heat exchanger can be improved.

In addition, the projection is formed integrally with the inner surface of one flat tube wall as one piece, and the projection is originally formed integrally with the flat tube wall. Therefore, as compared with a structure in which flat tube walls are connected to each other by using an independent member other than the tube, various advantages can be exhibited in terms of productivity and the like.

Further, according to the manufacturing method of the present invention, only by passing the tube strip material having a wall thickness thicker than the tube wall of the tube through the rolling roll, a single projection is formed integrally with the tube wall,
The protrusion can be molded with high efficiency, and thus the heat exchanger tube can be efficiently manufactured.

[Brief description of drawings]

FIG. 1A to FIG. 1E are cross-sectional views showing respective processes from the start, the process, and the end of rolling for forming partitioning protrusions.

FIG. 2 (f-1) is a sectional view showing a butt portion, FIG. 2 (e-2) is a sectional view showing a modified example of the butt portion, and FIG. 2 (g) is a state in which a U-shaped tube wall is being formed. It is sectional drawing which shows.

FIG. 3 is a sectional view of a tube.

FIG. 4 is a sectional view of a tube according to a modified example.

5 (a) is an overall front view of the heat exchanger, and FIG. 5 (b) is an overall plan view.

6A and 6B are sectional views of a conventional tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tube 8 ... Upper plane tube wall 9 ... Lower plane tube wall 11 ... Joining part 12 ... Projection 23 ... Upper rolling roll 23a ... Annular recess 24 ... Lower rolling roll

Claims (2)

[Claims] 1. A heat exchanger tube having an oval cross section having a joint extending in the longitudinal direction at any position in the circumferential direction of the tube wall, the tube being integral with the inner surface of one flat tube wall. The protrusion of one sheet is provided in a standing state in a manner extending in the longitudinal direction, and the protrusion is formed corresponding to the inner surface of the other flat tube wall or the inner surface of the other flat tube wall. A tube for a heat exchanger, characterized by being integrally joined to the protrusion. 2. A mode in which a joint portion extending in the lengthwise direction is provided at any position in the circumferential direction of the pipe wall, and a single protrusion formed integrally with the pipe wall extending in the lengthwise direction. A method for manufacturing a heat exchanger tube that is provided in an upright state, in which a tube molding material that is thicker than the tube wall of the tube to be manufactured is used and a protrusion is formed on the middle outer peripheral portion in the length direction. Using a rolling roll having an annular recess, the material is rolled in the thickness direction by the rolling roll to reduce the thickness to the thickness of the tube pipe wall, and the metal removed to the recess side of the roll by this thinning 2. A method of manufacturing a heat exchanger tube, wherein the protrusion is formed by bulging by using the roll recess.