JP2927051B2 - Heat exchanger - 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 such as an oil cooler, a radiator, a heater core, a refrigerant condenser or a refrigerant evaporator in which a corrugated inner fin is inserted in a flat tube.

[0002]

2. Description of the Related Art Conventionally, in a heat exchanger, a flat tube having a heat medium passage in which a heat medium flows is inserted into the heat exchanger, and the heat exchanger is inserted in the heat medium passage in a direction perpendicular to a flow direction of the heat medium. A device having an inner fin formed in a corrugated shape (Japanese Utility Model Laid-Open No. 61-84389) has been proposed.

[0003]

However, in the conventional heat exchanger, for example, as shown in FIG.
When the tube 101 and the inner fin 103 are assembled by crushing the tube 101 with a press or the like after inserting the
03 is assembled at a position biased toward one end of the tube 101 in the width direction.

Here, the present inventors have proposed a finite element method (FE).
FIG. 11 briefly shows the results of the analysis according to M). FIG.
As can be seen from FIG. 1, in the gap 106 between the tube 101 and the end portion 105 of the inner fin 103 caused by the deviation of the inner fin 103, a portion having a weak strength (a stress of 5 kg / mm ² or more, which is indicated by hatching in FIG. ) 104 can be confirmed to be concentrated. In the inner fin 103, it can also be confirmed that the stress at the end portion 105 is large, and the stress at the other portion (for example, the central portion) 107 except the end portion 105 is small.

Therefore, there is a problem that the strength of the entire tube 101 against the internal pressure is weak after the inner fin 103 is assembled to the tube 101 due to insufficient strength of the gap portion 106. In addition, as shown in FIG.
01, the dimension L of the gap 106, the brazing portion (fillet) between the inner fin 103 and the inner wall surface of the tube 101
And the plate thickness t of the inner fin 103. Since the dimension L of the gap 106 of the tube 101 is considered to be the maximum value at which the inner fin 103 can be inserted into the tube 101, the current dimension L of the gap 106 is the minimum value and cannot be changed. In addition, it is better not to change the dimensions of the fillet R because changing the size of the fillet R requires consideration of the change of the brazing material, the problem of poor brazing, and the like. Therefore, the strength of the gap 106 of the tube 101 can be improved by simply increasing the thickness t of the entire inner fin 103.

However, when the thickness t of the entire inner fin 103 is increased, the weight of the inner fin 103 is considerably increased, which is not favorable in terms of reducing the weight of the heat exchanger. An object of the present invention is to provide a heat exchanger in which the strength of the gap between the tubes is improved while suppressing an increase in the weight of the entire inner fin.

[0007]

According to the present invention, there is provided a flat tube having a heat medium passage in which a heat medium flows, and a tube disposed in the heat medium passage and orthogonal to a flow direction of the heat medium. And an inner fin which is formed in a wavy shape and has a plate thickness at an end portion in a direction perpendicular to the flow direction of the heat medium, which is thicker than other portions excluding the end portion.

[0008]

According to the present invention, in an inner fin formed in a wave shape in a direction perpendicular to the flow direction of the heat medium, the thickness of the end in the direction perpendicular to the flow direction of the heat medium is reduced by excluding the end portion. By making the inner fin thicker, the strength of the end portion of the inner fin is improved more than the other portions except the end portion. Therefore, the rigidity of the inner fin is improved, so that deformation of the inner fin, such as warpage or bending, is suppressed.

As a result, when the inner fin is assembled in the tube, the strength of the gap caused by the deviation of the inner fin is also improved. In addition, since the thickness of the end portion in the direction perpendicular to the flow direction of the heat medium is made thicker than the other portions except the end portion, the weight increases compared to the case where the thickness of the entire inner fin is made thicker. Can be suppressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat exchanger according to the present invention will be described with reference to one embodiment shown in FIGS. FIG. 1 is a diagram showing a tube and an inner fin, FIG. 2 is a diagram showing an inner fin, and FIG. 3 is a diagram showing a heat exchanger. Heat exchanger 1
Is used for an oil cooler, a radiator, a heater core, a refrigerant condenser or a refrigerant evaporator, and the like.
It comprises a header 3 and a plurality of tubes 4.

The first header 2 is a cylindrical container made of a metal such as aluminum or an aluminum alloy having excellent corrosion resistance and excellent heat conductivity, and is joined to one end of a plurality of tubes 4 by welding or the like. . The inside of the first header 2 is divided into a plurality of chambers by a partition plate (not shown). In addition, an inlet pipe 5 for flowing the heat medium into the first header 2 and an outlet pipe 6 for flowing the heat medium in the first header 2 to the outside are joined to the first header 2 by welding or the like. ing.

The second header 3 is a metal cylindrical container made of the same material as the first header 2, such as aluminum or an aluminum alloy, and is joined to the other ends of the plurality of tubes 4 by welding or the like. The inside of the second header 3 is divided into a plurality of chambers by a partition plate (not shown).

The plurality of tubes 4 are made of a metal such as aluminum or an aluminum alloy, which is the same material as the second header 3, and are formed in a flat oval cross section. A corrugated fin 7 for improving thermal conductivity is provided between the adjacent tubes 4. As shown in FIG. 1, each of the tubes 4 has a pair of opposing walls 8 parallel to each other in the width direction and opposing ends of the pair of opposing walls 8. 9
These form a heat medium passage 10 through which the heat medium flows.

As shown in FIG. 1, an inner fin 1 for improving the thermal conductivity is provided in the heat medium passage 10.
1 is inserted. This inner fin 11 is shown in FIG.
And as shown in FIG. 2, it is formed in a wavy shape so as to undulate in a direction perpendicular to the flow direction of the heat medium. Also,
The inner fin 11 is formed such that the plate thickness of both ends 12 in a direction orthogonal to the flow direction of the heat medium is thicker than the central part 13 as the other part excluding the both ends 12.

Here, the plate thickness of both ends 12 is
When the thickness of the inner fin 11 is t0.2, the thickness is set to a range up to the thickness t0.3 of the inner fin 11 before forming. Further, a crest 14 formed at a central portion 13 of the inner fin 11 is formed.
Are joined to a pair of opposed walls 8 of the tube 4 by brazing or the like.

The inner fins 11 are formed as shown in FIG.
The plate 15 made of metal such as aluminum or an aluminum alloy shown in FIG. 5 is press-formed by an upper roller 17 and a lower roller 18 of a forming roller 16 shown in FIGS. 5 to 9, for example. Upper roller 17
The lower roller 18 is formed so that the groove shape at both ends and the groove shape at the center are different from each other.
The gap 19 between both ends of the lower roller 18 and both ends of the lower roller 18 is formed wider than the gap 20 on the center side.

A method of manufacturing the inner fin 11 will be described with reference to FIGS. First, as shown in FIG.
A processing metal plate 15 having a thickness of, for example, t0.3 is cut into a predetermined width. Then, when the metal plate 15 is pressed between the upper roller 17 and the lower roller 18 of the forming roller 16, as shown in FIGS. 7, 8 and 9,
The thickness of the metal plate 15 is, for example, t0.27, t0.2
2, the band-shaped body 21 waving in the width direction becomes thinner in order as t0.20.

Since a gap 19 wider than the center gap 20 is formed between both ends of the upper roller 17 and both ends of the lower roller 18, the thickness of both ends 12 is large. Is, for example, t0.27 which is thicker than the central portion 13. Therefore, the belt-shaped body 21 in which the plate thickness of the both end portions 12 is larger than that of the central portion 13 is manufactured.

After the strip 21 is cut at a predetermined longitudinal dimension to produce the inner fin 11, the inner fin 11 is inserted into, for example, the elliptical tube 4 and the tube 4 is crushed. The tube 4 with the inner fins 11 as shown in FIG. 1 is manufactured. At this time, the inner fin 11 is biased in the tube 4, and a gap portion 22 having a dimension L is formed between the one end portion 12 of the inner fin 11 and the connection wall 9 of the tube 4.

Generally, when the gap 22 is formed, the strength of the tube 4 and the inner fin 11 is reduced. In this embodiment, the plate thickness t of the both ends 12 of the inner fin 11 is reduced.
Is formed thicker than the central portion 13 by, for example, t0.07, so that the strength of the one end portion 12 of the inner fin 11 can be improved.

As a result, the rigidity of the inner fins 11 is increased, so that deformation such as warping or bending of the inner fins 11 can be suppressed. Therefore, the strength of the gap portion 22 can be improved without increasing the thickness of the entire inner fin 11, so that an increase in the weight of the inner fin 11 can be suppressed. Furthermore, since the central portion 13 of the inner fin 11 can be made thinner than a conventional product, the weight of the inner fin 11 can be reduced, and the central portion 1 of the inner fin 11 can be reduced.
By improving the heat transfer efficiency of the tube 3, the heat exchange performance of the tube 4 can be improved.

(Modification) In this embodiment, the end portions 12 of the inner fin 11 are provided with thicker portions than the central portion 13. Only the central portion 13 may be provided with a portion thicker than the central portion 13. In this embodiment, the corrugated fins 6 are arranged between the adjacent tubes 4, but plate fins may be arranged so as to penetrate the plurality of tubes 4. The shape of the inner fin 11 may be any shape as long as it has a corrugated shape such as a shape with repeated irregularities. The method for forming the inner fins 11 is not limited to the present embodiment, but may be a method of forming in a plurality of steps, a method of forming using a forming roller having a different compression ratio, or the like.

[0023]

According to the present invention, the rigidity is improved by increasing the thickness of the end portion of the inner fin, and the warpage and bending of the inner fin itself can be suppressed. As a result, it becomes easier to insert the inner fin into the tube, and it is possible to suppress warpage and bending of the entire tube after assembly. Therefore, when the inner fin is assembled in the tube, the strength of the gap caused by the deviation of the inner fin can be improved. In addition, since the thickness of the end portion in the direction perpendicular to the flow direction of the heat medium is made thicker than the other portions except the end portion, the weight increases compared to the case where the thickness of the entire inner fin is made thicker. Can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a tube and an inner fin.

FIG. 2 is a perspective view showing an inner fin.

FIG. 3 is a cross-sectional view showing a heat exchanger.

FIG. 4 is a schematic view showing a forming roller.

FIG. 5 is a sectional view showing a forming roller.

FIG. 6 is a process drawing of an inner fin.

FIG. 7 is a process drawing of the inner fin.

FIG. 8 is a process drawing of the inner fin.

FIG. 9 is a process drawing of the inner fin.

FIG. 10 is a cross-sectional view showing a tube and an inner fin in a conventional heat exchanger.

FIG. 11 is an enlarged view of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 4 Tube 11 Inner fin 12 Both ends 13 Central part (other part)

Claims (1)

(57) [Claims] 1. A (a) flat tube having a heat medium passage in which a heat medium flows, and (b) a wave tube disposed in the heat medium passage and extending in a direction perpendicular to a flow direction of the heat medium. A heat exchanger comprising: an inner fin formed in a shape and having a plate thickness at an end in a direction orthogonal to the flow direction of the heat medium, which is thicker than other portions excluding the end.