JP2001296088A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability of a heat exchanger by removing brazing defect of a reinforcing member of a heat exchange tube of the heat exchanger. SOLUTION: There are provided headers 12 facing each other and a plurality of flat heat exchange tubes 14 extending transversely between the headers 12. The flat heat exchange tube 14 includes reinforcing members 14c that are protruded into the tube from opposite sides thereof and are brought into contact with each other and are joined with each other through brazing, and are further inserted into corresponding header holes 12a formed in the headers 12 at opposite ends thereof and are coupled with the headers 12 through brazing. In the heat exchanger 10, the header hole 12 is bulged inwards from a contour line of a cross sectional shape of the flat heat exchange tube 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a heat exchanger, and more particularly to a heat exchanger having a plurality of flat heat exchange tubes having a flat cross-sectional shape.

2. Description of the Related Art Conventionally, a relatively small and low-temperature heat exchanger used for a radiator of an automobile or an outdoor unit of an air conditioner has a flat heat exchange tube provided in a header in a transverse direction. The heat exchange tube and the header are joined by brazing. More specifically, as shown in FIG. 7, a header hole 32 is formed in the header 30 conventionally, and the heat exchange tube is fitted into the header hole 32 at both ends thereof and joined to the header 30 by brazing. You. In the prior art, the header hole 32 has substantially the same shape as the cross-sectional shape of the heat exchange tube as shown in FIG.

In recent years, a so-called welded tube in which both longitudinal edges of a strip made of aluminum alloy or copper alloy are joined to each other by butt brazing is used as a heat exchange tube. Since the welded pipe has a lower pressure resistance than the seamless pipe, a reinforcing portion protruding into the pipe from both sides is provided, and the pressure resistance is enhanced by joining the reinforcing parts to each other by brazing. I have.

[0004] In this type of heat exchanger, a brazing material is previously applied to the surface of a member constituting the heat exchanger. It is manufactured by being integrated as a heat exchanger. At the time of temporary assembly of the heat exchanger, each member is pressed together by a clamp tool to ensure the integrity of brazing, but in the area near the end of the heat exchange tube inserted in the header, Since the force is not sufficiently transmitted, the reinforcing portions are not joined to each other, and a predetermined pressure resistance of the heat exchange tube may not be obtained.

An object of the present invention is to solve such problems of the prior art, and it is an object of the present invention to remove brazing defects of a reinforcing member and thereby improve the reliability of a heat exchanger. .

Means for Solving the Problems According to the present invention, there is provided the present invention, wherein a pair of headers and a plurality of flat heat exchangers extending between the headers in a direction transverse to the headers. An exchange tube, wherein the flat heat exchange tube is a welded tube brazed together along a welding line extending in the axial direction, and protrudes into the tube from both side surfaces to be in contact with each other and joined by brazing. In a heat exchanger having a reinforcing portion and fitted into corresponding header holes formed in the header at both ends thereof, and joined to the header by brazing, the header hole is formed by the flat heat exchange. A heat exchanger characterized in that the heat exchanger has a shape that bulges inward from a contour line of a cross-sectional shape of a tube.

[0007] Corrugated fins can be arranged between the flat heat exchange tubes, and the flat heat exchange tubes are preferably formed of an aluminum alloy.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. First, referring to FIGS. 1 and 2, the heat exchanger 10 extends in a direction transverse to the direction of the center axis of the header 10 between the pair of left and right headers 12 opposed to each other. And a plurality of flat heat exchange tubes 14. The flat heat exchange tubes 14 are arranged at equal intervals in the longitudinal direction,
Corrugated fins 16 are provided between each. Further, the heat exchanger 10 has a pair of upper and lower pressing plates 18 for holding the flat heat exchange tubes 12 and the corrugated fins 14 in the vertical direction.

As shown in FIGS. 3 and 4, the flat heat exchange tube 14 is formed by bending a metal strip made of aluminum alloy, copper alloy or the like, and brazing along a welding line 14a extending in the axial direction. It is formed by a welded pipe. The flat heat exchange tube 14 has an oblong cross-sectional shape in which a semicircle is combined with both ends of a rectangle, and protrudes into the tube from opposite side surfaces 14b thereof, abuts on the tube, and is joined to each other by brazing. As a plurality of recesses 14c
have.

[0010] The header 12 has a plurality of header holes 12a for receiving the flat heat exchange tubes 14, and the flat heat exchange tubes 14 are fitted into the corresponding header holes 12a at both ends thereof, and are brazed. Header 1 by attaching
2 is joined. In the related art, the header hole has substantially the same shape as the cross-sectional shape of the flat heat exchange tube to be fitted as described above with reference to FIG. 7, but in the present embodiment, the header hole 12a is , And has a shape bulging inward from the contour of the cross-sectional shape of the flat heat exchange tube 12 indicated by a dashed line. More specifically, the shape of the header hole 12a is a shape that bulges inward from a contour line corresponding to the side surface where the recess 14c is formed.

Hereinafter, the operation of the present embodiment will be described according to the assembly process of the heat exchanger 10. First, a brazing material is applied to the surface of a metal strip such as an aluminum alloy or a copper alloy by a suitable method such as a cladding method. 3 and 4
Alternatively, a flat tubular molded product is prepared by bending or press molding as shown in FIG. At the same time, a corrugated fin with a brazing material applied to the surface is prepared.

The ends of each of the plurality of flat tubular molded products prepared as described above are fitted into the corresponding header holes 12a of the header 12. At this time, since the header hole 12a has a shape that bulges inward from the contour line of the cross-sectional shape of the flat heat exchange tube 12 indicated by the one-dot chain line in FIG. As shown by an arrow A in FIG. 1, the fitted region near the end is deformed by receiving a pressing force from the header hole 12a as shown by a dashed line. Therefore, the recess 14c as a reinforcing portion in the region near the end of the flat tubular molded product comes into contact with the corresponding recess 14c formed on the opposite side surface with sufficient pressing force.

Next, a corrugated fin is arranged between each of the plurality of flat tubular molded products, and a holding plate 18 (FIGS. 1 and 2) is arranged outside the uppermost and lowermost corrugated fins. At the approximate center of the direction, the adjacent flat tubular molded product and the corrugated fin are pressed by a clamp tool (not shown) from outside the holding plate 18,
The heat exchanger 10 is temporarily assembled. A clamping tool is provided from outside the holding plate 18 at a substantially central portion in the axial direction of the holding plate 18.
By applying a pressing force (not shown), the concave portion 14c as a reinforcing portion near the center also comes into contact with the corresponding concave portion 14c on the opposite side surface with sufficient pressing force. .

Next, the temporarily assembled heat exchanger is heated in a heating furnace at a predetermined temperature for a predetermined time, so that the brazing material applied to the inner and outer surfaces of the flat tubular molded product and the brazing material applied to the corrugated fin are melted. . Thereafter, the molten brazing material is solidified by cooling the heat exchanger, and the flat tubular molded product is brazed along the welding line 14a.
As shown in FIG. 4, the heat exchanger becomes a flat heat exchange tube 14 and is brazed firmly to the header 12 and the corrugated fins, and the temporarily assembled heat exchanger is integrated by brazing to complete the heat exchanger 10.

Having described the preferred embodiment of the invention,
The present invention is not limited to this embodiment, and it is obvious to those skilled in the art that various changes and modifications can be made.
For example, the reinforcing portion of the flat heat exchange tube is shown in FIGS.
As shown in FIG. 6, the recess 14c is not limited to the recesses 14c scattered on the side surface 14b of the flat heat exchange tube 14. For example, as shown in FIG. It is possible. The rib 14 '
In the process of forming the flat heat exchange tubes 14 ', the strips forming the tubes themselves can be formed by bending and brazed to each other by being heated by a heating furnace.

In the above-described embodiment, the flat heat exchange tube has been described as having an oval cross-sectional shape in which a semicircle is combined with two opposing sides of a rectangle. In a strict sense, the shape may not be a combination of a rectangle and a semicircle, and may be a shape in which both side surfaces 14b slightly bulge outward in FIG. Further, in the above-described embodiment, the welding line is illustrated as being formed in the curved surface portion of the flat heat exchange tube in the longitudinal direction, but the welding line is formed on one of two facing side surfaces. It may be.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view of the heat exchanger of FIG.

FIG. 3 is a partially enlarged perspective view of a region near an end of a flat heat exchange tube.

FIG. 4 is a cross-sectional view of the flat heat exchange tube of FIG.

FIG. 5 is a partially enlarged view of a header of the heat exchanger according to the embodiment of the present invention, showing a header hole.

FIG. 6 is a partially enlarged perspective view of a region near an end of a flat heat exchange tube according to another embodiment.

FIG. 7 is a partially enlarged view of a header of a heat exchanger according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Heat exchanger 12 ... Header 12a ... Header hole 14 ... Flat heat exchange tube 14a ... Welding line 14c ... Depression (reinforcement part) 14c '... Rib (reinforcement part) 16 ... Corrugated fin 18 ... Holding plate

Claims (3)

[Claims] 1. A flat heat exchange tube comprising: a pair of headers; and a plurality of flat heat exchange tubes extending between the headers in a direction transverse to the header, wherein the flat heat exchange tubes extend in an axial direction. A welded pipe brazed together along an extending welding line, having a reinforcing portion that protrudes into the pipe from both side surfaces and abuts each other and is joined by brazing, and formed at both ends thereof in the header. In the heat exchanger fitted in the corresponding header hole formed and joined to the header by brazing, the header hole has a shape bulging inward from a contour line of a cross-sectional shape of the flat heat exchange tube. A heat exchanger. 2. The heat exchanger according to claim 1, wherein the heat exchanger includes corrugated fins disposed between the flat heat exchange tubes. 3. The heat exchanger according to claim 1, wherein the flat heat exchange tube is made of an aluminum alloy.