JPH10111091A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce bad brazing by forming a center of both upper and lower tube surfaces or a one tube surface into a shape protruded to a fin side. SOLUTION: A tube 2 is formed by folding a plate on which a joint part 20 and beads 21 are provided at a central folded part 22 in the width direction of the plate, and a flat part 23 is formed between the joint part 20 and the folded part 22. Further, a plurality of flow passages 24, 24 are formed in the tube 2 to improve pressure resistance against pressure brought about by a heat exchange medium. The flat part 23 of the tube 2 is formed into a slight convex shape which takes as a top the neighborhood of the center in the width direction over a longitudinal direction in both sides, and is expanded to an inserted fin side. Hereby, upon lamination and assembling process pressing force is supplied from the fin so that the part expanded of the flat part 23 is pressed, i.e., it is so compressed that the upper and lower thickness of the tube 2 substantially falls within the thickness (b) to the thickness (a).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger in which tubes are stacked in parallel with fins interposed therebetween, and more particularly, to a brazing property of a tube having a bead for dividing the inside into a plurality of flow paths. It is an improvement.

[0002]

2. Description of the Related Art Conventionally, tubes are stacked with fins interposed therebetween, and the ends of the tubes are respectively connected to distribution collecting members such as header pipes, and a heat exchange medium is provided in the distribution collecting member. Laminated heat exchangers that are meandered and circulated between joints a plurality of times are known.

[0003] As the tube of the laminated heat exchanger, a tube having a plurality of flow paths therein is used in order to improve the heat exchange rate and the pressure resistance. In particular, a tube of a heat exchanger used as a condenser is required to have an excellent heat exchange rate and pressure resistance.

[0004] As this kind of tube, a bead type tube which separates an internal flow path of the tube by a circular or elongated protrusion (hereinafter referred to as a bead) provided to project from the flat portion into the tube, for example, As disclosed in Japanese Utility Model Application Laid-Open No. 5-52565, an inner fin having a corrugated cross section is inserted into a tube tube to press the tube so that the inner fin is clamped by the inner wall of the flow path. Are divided into a plurality of inner fins.

[0005] In particular, the bead type does not require a separate inner fin and has a reduced number of components compared to the inner fin type. Since the tube pressing step for clamping the inner wall is omitted,
This has the advantage of lower manufacturing costs. In addition, it is possible to increase the heat exchange rate by causing turbulence in the heat exchange medium flowing through the tube depending on the arrangement and shape of the beads.

[0006] These tubes have, for example, a wall thickness of 0.4.
A plate made of an aluminum material or an aluminum alloy material having a size of about mm is bent or two plates are overlapped.

FIG. 5 is a cross-sectional perspective view of a conventional tube. This tube 13 has a long plate-like single plate formed to a predetermined dimension, and the center of the plate in the width direction is fixed to a predetermined length. It is formed by bending at a round radius.
The plate is provided with a flat joining portion 20 and a long groove-shaped bead 21 on both edges in the plate width direction in advance by roll forming or press forming. It is formed in a flat shape by being bent at the center bent portion 22 so as to abut each other.

FIG. 6 is a sectional perspective view of a conventional tube 13 formed by stacking two plates. The tube 13 is formed by providing a joint 20 and a bead 21 on two plates, respectively, and overlapping the joints 20, 20 so as to abut each other.

Each of these is formed in a flat shape in the width direction longer than the thickness direction, and the flat portions 2 on both sides facing each other.
The outer wall intervals (thickness of the tube 13) are uniformly formed to have a predetermined thickness (for example, about 1.7 mm) corresponding to the fins and the header pipe.

The joints 20 and the top of the bead 21 and the inner wall of the channel 24 facing the joint need to be joined by brazing.
By pressing the flat portion 23 against the fins, the flat portion 23 is kept in contact with the fins or in a state close to the molten brazing material from the surface of the plate at the time of brazing.
At this time, if necessary, a jig or the like that presses the layer of the tube with the fin interposed therebetween from both sides is used. In addition, as shown in the drawing, the bead 21 has a top portion abutting against the inside of the flat portion 23 serving as an inner wall portion of the flow path 24, and also has a top portion abutting with another bead provided at the opposed portion. In some cases.

The tube 13 thus formed is
Are stacked with fins interposed therebetween, and their ends are connected to a distribution collecting member such as a header pipe.

[0012] Then, the assembled body (Assy) composed of the tube 13, the distribution collecting member and the fins is subjected to a heat treatment and brazed integrally. Prior to this heat treatment, the brazing material is clad at required places. Usually, a brazing material is clad on the front and back surfaces of the plate forming the tube in advance.

[0013]

However, in the integrated brazing of a laminated heat exchanger using tubes as described above, the top of the bead and the inner wall portion of the flow passage partially become defective in brazing. However, there is a problem that causes a decrease in heat exchange rate, a pressure defect, and the like.

This is because the corresponding dimensions of each part such as the height of the joint and the height of the bead have some variation,
The bite of each tube is slightly displaced due to the degree of assembling with the distribution collecting member and the fin, and the top of the bead and the inner wall of the flow path are slightly separated, so that sufficient brazing material cannot be obtained between them This is because there are places.

[0015] In this case, a relatively good brazing is possible because the molten brazing material also intrudes from the outer surface of the plate between the joining portions, but the top of the bead and the inner wall portion of the flow path are: In the meantime, only the molten brazing material enters from the inner surface of the plate.

Therefore, such a tube has poor reliability in performance due to inferior yield, and also has a disadvantage that a satisfactory heat exchange rate and pressure resistance cannot be obtained even when used for a capacitor.

In view of the above, the present invention provides a method in which a pressing force is applied from a fin to a flat portion at the time of assembling, so that the top of the bead can be brazed to an inner wall portion facing the top. It is an object of the present invention to provide a heat exchanger capable of straightening and reducing brazing defects.

[0018]

SUMMARY OF THE INVENTION The present invention relates to a heat exchanger in which a tube in which a bead for dividing into a plurality of flow paths is integrally formed is stacked in parallel via fins. This is a heat exchanger having a configuration in which an intermediate portion of one tube surface is formed in a shape protruding toward the fin.

Therefore, when the tubes are stacked, the bulged portion is appropriately compressed by the pressure contact of the fins, and the top portions of the tubes or the bead and the inner wall portion of the tube are corrected to a brazable state. .

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to specific examples shown in the drawings.

FIG. 1 is a front view of a heat exchanger according to this embodiment. In this heat exchanger 1, a plurality of tubes 2, 2 and corrugated fins 3, 3 are alternately stacked in parallel with each other. ,
Both ends of the laminated flat tubes 2 are inserted and connected to the tube insertion holes 5 and 5 of the header pipe 4 erected on the left and right, respectively. In addition, the laminated tube 2
Side plate connection holes 6 are provided in the header pipes 4 on the upper end and lower end of the side plate. Both ends of a side plate 7 having a U-shaped cross section are inserted into these side plate connection holes 6 and joined. ing. Further, the upper and lower end openings of the header pipe 4 are closed by caps 8. Further, an inlet joint 9 is connected to one header pipe 4,
An outlet joint 10 is connected to the other header pipe 4. Furthermore, at the required locations of both header pipes 4,
A slit 11 having a predetermined shape is formed, and a partition plate 12 for partitioning the header pipe 4 in the longitudinal direction is inserted from the slit 11 and disposed.

In such a heat exchanger 1, the heat exchange medium flows between the inlet joint 9 and the outlet joint 10 in a meandering manner a plurality of times. That is, the heat exchange medium supplied to the inlet joint 9 of the heat exchanger 1 is meandered a plurality of times between the left and right header pipes 4 and 4 via the tube 2 and passes through the tube. Then, heat is exchanged with the outside and discharged from the outlet joint 10.

In FIG. 2, the tube 2 is formed by bending a single plate provided with a joint portion 20 and a bead 21 by roll forming at a central bent portion 22 in the plate width direction. A flat portion 23 having a predetermined shape to be described later is formed between the bent portion 22 and the bent portion 22.

That is, the tube 2 is made of a thin plate-shaped aluminum brazing sheet having good thermal conductivity, good moldability and good brazing properties as a material, and has a joining portion having flat portions at both ends in the width direction. As in the prior art, the joining area is increased by the joining portions 20 so that a sufficient brazing joint strength can be secured.

Each of the tubes 2 has a bead 21 having a predetermined height over the entire length in the longitudinal direction before assembling the tube 2 at least.

The beads 21 are provided at predetermined positions in the width direction of the tube 2 alternately inward in the tube direction from the inner surface of the tube 2, and are provided in two rows in the present embodiment. The channels 24 are formed. That is, the projecting height of these beads 21 is set to be substantially equal to the inner width of the tube 2, and the portion of the tube 2 facing these beads 21 is formed in a plane. Therefore, the tube 2 facing the top of each bead and the inner surface of the tube are joined to form a plurality of flow paths 24, 24 in the tube 2, and heat exchange of the medium flowing through these flow paths 24, 24 is performed. In addition to increasing the efficiency, the portion forming the flow path functions as a reinforcing member, and improves the pressure resistance against the pressure caused by the heat exchange medium.

The flat portion 23 of the tube 2 is formed in a gently convex shape with the bent portion 22 being bent along the longitudinal direction on both sides thereof, with the top near the center in the width direction. It slightly protrudes toward the fin 3 to be interposed. As shown by the two-dot chain line in FIG. 2, the thickness of the tube 2 in this example is set to a thickness a (for example, 1.7 mm) near the edge and slightly larger than the thickness a near the center in the width direction ( For example,
The thickness a is about 0.1 mm to 0.2 mm with respect to the thickness a = 1.7 mm). In this example, the flat portion 23 at the place where the bead 21 is provided and at the place where the inside corresponds to the inner wall of the flow path 24 facing the top of the bead 21 bulges toward the fin 3 side.

As shown in a partially cutaway perspective view of FIG. 3, such a tube 2 is laminated on the upper and lower surfaces thereof with fins 3 interposed therebetween. The pressing force from the fin 3 is applied. That is, this fin 3 is made of a thin metal material having excellent heat conductivity,
It is formed in a wavy shape meandering up and down. The height of the fins 3 meandering is set to the height reaching the non-bulging portion of the tubes to be stacked, as in the conventional case.

Accordingly, the height of the fins 3 is set as described above, and the flat portion 23 of the tube 2 is bulged to the fins 3 side. Is supplied, the bulged portion of the flat portion 23 is pressed, that is, the tube 2
Are compressed so that the upper and lower thicknesses thereof become approximately the thickness b to the thickness a.

If there is a gap between the top of the bead 21 and the inner wall of the flow path 24 facing the top, the upper and lower flat portions 23 are pressed and deformed, and the tube 2 itself is appropriately moved up and down. As they are compressed from each other, they are brought closer together and corrected into abutting or closer proximity.
That is, since at least the upper and lower portions of each bead are bulged in the vertical direction, the upper and lower flat portions 23 are pressed and deformed, and the inner wall portion facing the bead 21 approaches the bead side, and Also approach the opposing inner wall surface.

Therefore, even in the event that the corresponding dimensions of the respective parts are varied or the bites of the respective parts are displaced due to the assembling condition, as long as the flat part 23 is compressed and deformed,
The formation of a gap between the top of the bead 21 and the flow path 24 can be prevented.

The fins 3 are mounted in close contact with the tube 2 by slightly deforming the waveform even if the flat portion 23 is not pressed and deformed to a perfect plane.

The end of the tube 2 is inserted into the insertion hole 5 of the header pipe 4, and this assembly is fed into a furnace after being coated with a flux, and brazed integrally by heat treatment. The joining portions 20 and 20 and the top of the bead 21 and the flat portion 23 are brazed and joined in a state where the molten brazing material is sufficiently obtained.

In the above-described specific example, the beads are alternately projected from the inner surfaces of the upper and lower flat portions provided on the tube. However, the beads may be provided on one surface. Alternatively, the beads may be projected from the opposed inner surfaces so that the tops of the beads come into contact with each other.

Further, the flat portion may bulge only one of the upper and lower surfaces of the tube, or bulge only a necessary portion near the bead.

Therefore, according to the present embodiment, the tube is formed in a vertically swelling shape with the vertex near the center of the tube, so that the swelling portion is appropriately compressed and deformed by the pressing force from the fin, and is joined. The portions and the top of the bead and the inner wall portion facing the bead can be corrected to an optimal approach / contact state for brazing, and the brazing property of the portion can be reliably improved.

That is, there is a slight variation in the corresponding dimensions of each part such as the height of the joint and the height of the bead, and the bite of each tube is slightly displaced due to the condition of assembling with the distribution collecting member and the fin. Thus, even when the top of the bead and the inner wall of the flow path are slightly separated from each other, it is possible to correct the approach / contact state optimal for brazing.

Further, even when the top of the bead and the inner wall portion of the flow channel enter only the melted brazing material from the inner surface of the plate therebetween, the optimum approach / contact state for brazing is provided. Brazing can be performed reliably.

As a result, the brazing property of the beads is improved, so that the yield can be improved, the heat exchange rate and the pressure resistance can be enhanced, and further, various types of laminated heat exchangers such as capacitors can be used. Can also respond.

Further, in the above-mentioned specific example, a tube formed by bending a single plate has been described. As a tube formed from the plate, as shown in FIG. As described above, the present invention can also be applied to a tube 2 formed by stacking two plates.

[0041]

As described above, the present invention relates to a heat exchanger in which tubes in which beads for dividing into a plurality of flow paths are integrally formed are stacked in parallel via fins.
A heat exchanger having a configuration in which an intermediate portion between both upper and lower surfaces of one of the tubes or one of the tube surfaces is formed to protrude toward the fin side.

Therefore, when laminating the tubes, the bulging portion is appropriately compressed by the pressure contact of the fins, and the top portions of the tubes or the bead and the inner wall portion of the tube are corrected to a brazable state. Can be.

As described above, according to the present invention, defective brazing can be reliably reduced.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a heat exchanger according to a specific example of the present invention.

FIG. 2 is a partially broken perspective view showing the tube of the present example.

FIG. 3 is a partially broken perspective view showing a state in which the tube of the present example is temporarily assembled.

FIG. 4 is a partially cutaway perspective view showing a split plate type tube according to another embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view showing a one-plate type tube according to a conventional example.

FIG. 6 is a partially broken perspective view showing a split plate type tube according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Tube 3 Fin 4 Header pipe 5 Tank plate 6 End plate 7 Tube insertion hole 8 Blind cap 9 Partition plate 10 Inlet joint 11 Outlet joint 12 Side plate 13 Tube 20 Joint part 21 Bead 22 Bent part 23 Flat part 24 channels

Claims (1)

[Claims] 1. A heat exchanger in which a tube in which a bead for dividing into a plurality of flow paths is integrally formed is laminated in parallel via a fin, wherein both the upper and lower sides of the tube or an intermediate portion of one of the tube surfaces is provided. And a heat exchanger formed in a shape bulging toward the fin side.