JPH0486489A - Tube for heating exchanger - Google Patents

Abstract

PURPOSE:To improve the manufacturing efficiency by a method wherein a plurality of bent projections are formed on the flat surface of a flat tube and the tip ends of the projections are abutted against an opposing flat surface to connect them integrally while connecting bent rims are formed integrally with side rims. CONSTITUTION:Bent projections 6, projected inwardly in a tube 1 for heat exchanging, are formed on upper and lower flat walls 2, 3 and the tip ends of the projections 6 are abutted against the inner surfaces of the opposed flat walls 2, 3 to connect them integrally to the inner surfaces through brazing. Bent rims 2a, 3a for connection are formed on the other end rims of the flat walls 2, 3 in parallel to each other while both of them are superposed to connect them integrally. The bent projection 6 function as reinforcing members whereby a strength against compression and a resistance to an internal pressure can be increased. The bent rims 2a, 3a are connected at the side rims of the tube 1 under abutted condition whereby the operability in connecting works can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to tubes for heat exchangers, particularly flat tubes used in multi-flow heat exchangers used as condensers for car coolers.

BACKGROUND OF THE INVENTION Conventionally, a serpentine tube type heat exchanger has generally been used in a car cooler condenser. That is, a core is generally used by bending a multi-hole extruded flat tube called a harmonica tube into a meandering shape and arranging fins between its parallel parts.

In response to this, recently, based on the demand for reducing refrigerant flow resistance, improving heat exchange efficiency, reducing weight, and reducing thickness, the use of so-called multi-flow heat exchangers as condensers has been proposed and put into practical use. It has come to be For example, as shown in Fig. 8, this multi-flow type heat exchanger connects a large number of flat tubes (23) between a pair of left and right pipe headers (21) (22), and adjacent tubes ( 2
3) By arranging the fin (24) between (23) and partitioning the inside of the header (21) (22) with a partition member (25) at an appropriate position in the length direction, one of the headers (2]) A meandering refrigerant circuit is formed from the refrigerant inlet (26) at the upper end to the refrigerant outlet (27) at the lower end of the other header (22).

The tubes (23) used in such multi-flow heat exchangers require sufficient pressure resistance to withstand the pressure applied by the high-pressure gaseous refrigerant being handled. A porous flat tube made of aluminum extrusion is used. That is, as shown in FIG. 9, the peripheral wall (23a) has an elliptical cross section, and has one or more partition walls (23b) continuous in the length direction of the tube to form a plurality of internal spaces. The refrigerant passage (23c) is divided into independent refrigerant passages (23c).

Problems to be Solved by the Invention However, the tube made of the extruded tube as described above (
As long as 23) is used, there are manufacturing technology constraints on reducing the tube height (H), and there are limits to improving the heat exchange efficiency. That is, in order to improve heat exchange efficiency, within the limited area of the heat exchanger core, it is necessary to reduce the flow resistance of the air flowing through the core as much as possible, and to increase the contact area with the air. Although it is effective to measure the height (H) of the tube (23), it is not possible to make the height (H) of the tube (23) sufficiently low.As a result, the tube increases air flow resistance and The number of hanging tubes that can be installed is limited, and the heat transfer contact area with the air cannot be sufficiently increased.

To solve these problems, it has recently been proposed to use electric resistance welded tubes (for example, in Japanese Patent Publication No. 62-207
No. 572). In the case of this electric resistance welded tube, the tube wall is sufficiently thin, for example, 0.4 to 0.0 mm. It is possible to make the tube about 51#I, and as a result, the tube height can be adjusted to 1.5 to 1.5 mm.
It is possible to form it to an extremely low value of about 7#.

However, when used as a condenser, the tube made of the ultra-thin-walled electric resistance welded tube does not have the ability to withstand pressure because it handles high-pressure gaseous refrigerant sent from the compressor as mentioned above. There is a significant shortage and it cannot be put to practical use as it is.

For this reason, in the conventional proposal,
As seen in Publication No. 2, an inner fin material formed into a corrugated shape in the width direction is separately inserted into the flat electric resistance welded pipe, and the fin material can also be used as a reinforcing member by brazing or joining it to the inner surface of the pipe wall. It is intended to function and obtain the required pressure resistance.

However, such conventional electric resistance welded tubes are difficult to manufacture, especially when the height is 1.5 to 1.5 mm.
It is extremely difficult to insert the inner fin material over the entire length of the ultra-thin 7# flat tube, resulting in poor productivity and high costs.

This invention further solves these problems and improves heat exchange efficiency by making the tube height sufficiently low, has sufficient pressure resistance, and is easy to manufacture. The purpose of the present invention is to provide a tube for a heat exchanger that is suitable for dexterity.

Means for Solving the Problems In order to achieve the above object, the present invention provides a tube for a heat exchanger in which a pair of band-shaped flat walls facing each other with a predetermined interval have a U-shaped bent portion at one side edge. A flat tube continuous through the tube and integrally joined at the other side edge, wherein one or more bent protrusions projecting inward are formed on the flat wall part, and the top ends of the bent protrusions are opposite to each other. a bent edge for joining that is brought into contact with the inner surface of the flat wall portion or the top end of a corresponding bent protrusion protruding from the wall portion to be joined together, and parallel to the other side edges of both said flat wall portions; It is characterized in that a portion is formed, and the edges are joined and integrated in an overlapping state.

Alternatively, it may be a pair of molded plates having one or more bent protrusions or protrusions formed on the inner surface, or a flat tube that is stacked facing each other with the bent protrusions inside and joined together at both side edges. , the top end of the bending protrusion is brought into contact with and integrated with the inner surface of the flat wall of the opposing molding plate or the top end of the corresponding bending protrusion protruding from the wall, and is attached to both side edges of the molding plate. It is characterized in that bent edges for joining that are parallel to each other are formed, and the edges are joined together in an overlapping state.

The bent protrusions are formed as a continuous bent double wall in the length direction of the tube and protrude from both the upper and lower planar walls of the tube in an alternate arrangement. The internal space can be partitioned to form a plurality of independent refrigerant passages.

Further, the bent protrusions are formed in the form of a large number of dimples by partially recessing the flat wall portion of the tube, and the large number of dimple-shaped bent protrusions are scattered so that the inside of the tube is The space may also be formed into a stray refrigerant passage.

The bent edge for joining can be formed so as to be folded into the tube, or can be formed so as to protrude outside the tube.

Example (Example 1) In the example shown in FIGS. 1 and 2, the heat exchanger tube (1) has upper and lower strip-shaped planar walls that face each other with an interval of, for example, 0°8 mm. Parts (2) and (3) are
It consists of a flat tube with an oval cross section that is continuous at one side edge via a U-shaped bent part (4) and joined and integrated at the other side edge.

Bent edges (2a) (3a) for joining of a predetermined width are formed on the other side edges of both the planar wall portions (2) and (3), which are rolled inward and parallel to each other, and have a predetermined width. The edge (2
a) (3a) Join with the two overlapped (
5) It has been done. By adopting such a joining structure, not only the workability is improved compared to the case where the side edges are simply butted and joined, but also stable brazing is possible even when brazing in a furnace. In this way, the other side edge may be joined by brazing or by electric resistance welding.

In addition, in the case of brazing, it is preferable from the viewpoint of workability to perform the brazing together with other heat exchanger components such as tubes in a furnace.

Each of the upper and lower plane walls (2) and (3) has a tube (1
) are formed with two inwardly protruding bent protrusions (6) arranged alternately with each other in the width direction. This bent protrusion (6) is connected to the flat wall portion (2).
(3) is folded inward into a V-shape and the two side walls are brought into close contact with each other to form a bent double wall, which is continuous in the length direction of the tube (1). Each of the bent protrusions (6) has its top end abutted against the inner surface of the opposing flat wall (2') (3), and
It is joined and integrated with the inner surface by brazing, and the bending protrusion (6) itself is also integrated by brazing the contact surfaces of both walls of the bent double wall. These connections are performed by using a double-sided aluminum plating sheet having a brazing material layer on both the inner and outer surfaces as the tube material. Therefore, during the assembly of the heat exchanger, the brazing of the fins (24) and the tubes (1), and the tubes (1) and the headers (21) and (22) are performed simultaneously with the joining operations. It is something.

Therefore, after the above-mentioned brazing, the inner space of the tube (1) is divided into a plurality of independent refrigerant passages (8) in the width direction using the bent protrusion (6) as a partition wall. being done.

In addition, the dimensions of the tube (1) are such that the tube wall thickness (1) is preferably 0.15 to 0.5 mrn, particularly, for example, 0.
．． 4 mm, the tube width (w) is 12-20 mm, especially for example 16 mm, the tube height (h) is 1. 2-2.
0 mm, particularly, for example, 1.6 mm.

To manufacture the tube (1), first, as shown in Fig. 2 (b), a belt-shaped material (7) of the required width made of an aluminum plating sheet is sandwiched at the part to be bent at the center in the width direction. A plurality of bent protrusions (6) protruding toward one side are formed in a bent manner on both the left and right sides. To form this bent protrusion (6), first, as shown in Fig. 2 (A), in order to correctly set the formation position of the bent protrusion (6), one side wall section is aligned perpendicularly to the plate surface. A deformed approximately V-shaped bead portion (with the other side wall portion inclined at an angle (θ) of about 30 degrees, for example) with respect to the one side wall portion (
6'), and then, as shown in FIG. 2(b), by applying a trimming process to bring the both side walls of the bead part (6') into a close contact and shaping it into a predetermined shape. It is best done.

Next, the strip material (7) on which the bent protrusion (6) has been formed is bent into a U-shaped cross section with a predetermined radius of curvature as shown in FIG.
Both side edges (7a) (7a) are folded inward to form bent edges (2a) (3a), and the bent edges (2a)
(3a) The two are stacked one on top of the other and then welded in a furnace or by electric resistance welding to form a flat shape with an oval cross section of predetermined dimensions. It is manufactured into a tube material as shown in the enlarged view.

FIG. 3 shows a modification of the tube (1-), in which the bent protrusions (6a) and (8b) are raised from the vertically opposing plane walls (2 and 3) at corresponding positions. The bending protrusion (6
a) (6b) They are brought into abutting contact at their top ends, and are integrally brazed to each other. The rest of the structure is the same as that of the embodiment described above, and the manufacturing thereof is also carried out according to the embodiment described above.

(Embodiment 2) FIG. 4 shows another embodiment. In this embodiment, the tube (11) has two molded plates (Pi) (P2) formed with bent protrusions (16) that protrude inward in a manner that is arranged alternately with respect to the width direction of the tube (11). They are stacked facing each other with the bent protrusions (16) on the inside and are integrally joined at both side edges. Bent protrusion (1
Two pieces of 6) are formed on each of the upper and lower molded plates (PL) (P2).

Both side edges of the molded plate (PI) (P2) are bent into an L-shape and have bent edges (12a) (13a).
) with a corresponding bent edge (1
2a) (13a) They are joined and integrated by brazing in a state where they are overlapped. However, instead of such brazing, electric resistance welding may be used. The other configuration of this tube (11) is the same as that of the first embodiment, and detailed explanation will be omitted.

Even in the case of this second embodiment, as a modification thereof, the bent protrusions (16) are formed at positions corresponding to each other on the upper and lower plane wall parts (12) and (13), and the top ends of the bent protrusions (16) are placed in contact with each other. Brazing may be performed by joining and brazing the parts into one piece.

In addition, in order to improve the assemblability of the tube (11), it is preferable to temporarily fix both plates (PL) (P2) prior to joining and integrating them. For example, as shown in FIG. 5, the bent edge (13a) of the lower plate (P2) extends over the entire length of the tube (11').
may be formed into a U-shape so that the edge (13a) embraces the bent edge (12a) of the upper plate (PL). In this case, the bent edges (12a) (13a) are formed on both plates (PL) (P2), respectively, and the bent edge (13a) of the lower plate (P2) is formed.
a), the bent edge (+2a) of the upper plate (Pl)
It can be easily assembled by inserting the

In addition, as shown in Figure 6 (a), the lower plate (P2)
A protruding edge (13b) that protrudes laterally is extended to a part of the bent edge (13a) of the upper plate (Pl).
A notch (12b) is formed at a corresponding position of the bent edge (12a) of both plates (PI) as shown in FIG. 6(b).
(P2) and the protruding edge (13b)
The tube (If'') may be assembled by bending and fixing it toward the notch (12b).

Alternatively, as shown in Figure 7 (a), a rib (13c) is formed in an upwardly protruding shape on the bent edge (13a) of the lower plate h (P2), and the upper plate (P]) is bent. A locking hole (12c) corresponding to the rib (13c) was formed at a corresponding position on the edge (12a), and both plates (PL) (P2) were overlapped as shown in FIG. 7(B). In this state, crush the rib (1-3c) and insert it into the locking hole ([
2C) by locking it in the tube (11'''
) may be assembled.

In any of the above embodiments, the bent protrusion (6) (
16) indicates one formed along the length of the tube (1) (11) or a flat wall (2)
(3) (12) (13) are partially inwardly recessed into a substantially hemispherical or substantially U-shaped cross section to form a large number of scattered dimples, and these are arranged vertically in correspondence with each other. They may be formed at different positions, their top ends abutted against each other, and they may be joined and integrated by brazing. In such a case, the internal space within the tube is
Due to the dimple-shaped bent protrusions mentioned above, a complicatedly bent stray refrigerant passage is formed, and the refrigerant is stirred by the bent protrusions as it flows through the refrigerant passage, further promoting heat exchange. be done.

In addition, in Example 1, the bent edge was bent inward, and in Example 2, the bent edge was bent outward, but in Example 1, the bent edge was bent outward, Further, in the second embodiment, it may be bent inward.

Effects of the Invention The tube for a heat exchanger according to the present invention is manufactured as a flat tube by joining and integrating one side edge or both side edges as described above, so that the tube wall can be made sufficiently thin. , it is possible to manufacture an extremely thin tube with an extremely low height. Therefore, it is possible to increase the number of heat exchangers installed within a predetermined limited area of the heat exchanger core, increase the contact area with the air flowing through the core, and reduce the flow resistance of the air. Therefore, it is possible to construct a heat exchanger with even better heat exchange efficiency.

In addition, although the tube is manufactured by joining one side edge or both side edges as described above, a bending protrusion protrudes from the upper and lower opposing plane walls, and the top end of the tube is attached to the other side. The bent protrusions function as reinforcing members and have high compressive strength as well as internal pressure resistance. It also has excellent properties and can be used as a condenser tube, comparable in strength to flat tubes made of extruded material.

Furthermore, since the joints at the side edges of the tubes are integrated by overlapping the bent edges for joints that are parallel to each other, the side edges of the tubes are not joined as in conventional ERW tubes. Compared to the case where the edges are simply butted and joined, the overlapping work can be performed relatively roughly, so the workability of joining is improved.

Furthermore, since the bonding is performed in a state of surface contact, strong bonding strength can be obtained. Therefore, instead of conventional electric resistance welding, it is possible to perform solder joints, and in turn, the joints can be brazed together with other heat exchanger components in a furnace, further improving manufacturing efficiency. can do.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a perspective view of a tube, and FIGS.
C) and D are cross-sectional views showing the manufacturing process, and FIG. 3 is a cross-sectional view of a modified tube. Figures 4 to 7 are
This shows an example, in which Fig. 4 is a perspective view of the tube, and Fig. 5 is a perspective view of the tube.
The figure is a cross-sectional view of the tube of a modified example, Figure 6 (a) is a perspective view of another modified example with the upper and lower molding plates separated, and Figure 6 (b) is a perspective view of the upper and lower molding plates stacked together. Fig. 6(a) is a cross-sectional view taken along the vt-vr line in the state, and Fig. 7(a) shows yet another modification; Fig. 6(a)
FIG. 7(B) is a perspective view corresponding to FIG. 6(B). FIG. 8 is a front view showing an example of a heat exchanger using the tube according to the present invention, and FIG. 9 is a sectional view of a conventional flat tube made of extruded material. (1) (11)...Tube, (2) (3)
(12) (13)...Flat wall part, (2a) (
3a) (12a) (13a)...Folded edge, (4
)...Bending part, (6) (16)...Bending protrusion, (
PI) (P2)...Molding plate. Above ”Q,,:- Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A pair of band-shaped flat wall portions (2) and (3) facing each other with a predetermined interval are continuous at one edge via a U-shaped bent portion (4) and the other side is continuous. A flat tube (1) integrally joined at the edges, wherein one or more bent protrusions (6) protruding inwardly are formed on the flat wall parts (2) and (3). The top end of the bent protrusion (6) faces the flat wall part (2).
)(3) or the top end of the corresponding bent protrusion (6) protruding from the wall portions (2)(3) and are joined and integrated, and the two planar wall portions (2)(3) ) are formed with bent edges (2a) and (3a) for joining that are parallel to each other, and the edges (2a) and (3a) are parallel to each other.
a) (3a) A tube for a heat exchanger, characterized in that the tubes are joined together in a superposed state. (2) A pair of molded plates (P1) (P2) each having one or more bent protrusions (16) protrudingly formed on the inner surface are stacked facing each other with the bent protrusions (16) inside, and both side edges Flat tube (11) joined and integrated at
The flat wall portions (12) (13) of the molded plates (P1) (P2), the top ends of the bent protrusions (16) facing each other,
or the top ends of the corresponding bent protrusions (16) protruding from the walls (12, 13), and are joined and integrated, and the molded plates (P1) (P2) are provided with Parallel joining folded edges (12a) (13a) are formed;
) (13a) A tube for a heat exchanger, characterized in that the tubes are integrally joined in a superposed state.