JPS6314092A - Heat exchanger - Google Patents

Abstract

PURPOSE:To increase the quantity of air flowing into the louvered area so as to fully make use of the heat dissipation function of the louver and improve the fin rigidity by forming saw-toothed projections in the flat area of a fin between the louvered area and the flat tube. CONSTITUTION:A heat exchange takes place between a fin 4 and air flowing on its surface. A louver 8 formed in the fin 4 improves the thermal conductivity with air, and enhances the heat exchanging efficiency with air by increasing the drafting resistance. Further, by forming forming saw-toothed projections in the flat area 9 between the louver 8 and a flat tube 3, the thermal conductivity of the flat area 9 is increased, improving the overall thermal conductivity of the fin 4. Not only the heat exchanging efficiency is improved, but also the flow resistance of cooling air flowing along the flat area 9 can be made larger and the saw-toothed projections 10 directs the cooling air to the louver 8. As a result, the quantity of air flowing in the louvered area 9 where the heat dissipation performance is high can be made larger so as to improve the heat exchanging efficiency. Further, the saw-toothed area 10 increases the mechanical strength of the flat area.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat exchanger suitable for automobile radiators and automobile air conditioning systems. [Prior Art] Heat exchangers used in automobile radiators and automobile air-conditioning systems conventionally consist of flat tubes through which refrigerant and mixed water pass, as shown in Japanese Utility Model Application Publication No. 59-97378. It has a laminated structure in which corrugated fins or plate fins are alternately arranged, and these fins are brazed or soldered to the flat tube.

In order to improve heat exchange with the air, the fins are cut and raised with louvers aimed at the leading edge effect of the temperature boundary layer. In other words, when heat from the flat tube is conducted to the fins, heat is exchanged with the air flowing on the surface of the fins, but forming louvers increases the heat transfer efficiency with the air. Good heat exchange takes place.

[Problem that the invention seeks to solve]

However, in the past, the space between the louver portion formed on the fin and the flat tube to which the side ends of the fin were joined simply maintained a flat shape.

With such a structure, the air flowing into the fins avoids the louver part with high resistance and flows at a high speed through the flat parts with low resistance formed on both sides of the louver part, resulting in a decrease in heat transfer coefficient. Not only is the efficiency not good because heat is exchanged in a small flat area, but the amount of air passing through the louver is relatively small, so the heat exchange function of the louver is not fully utilized.

[Means for solving problems]

The present invention aims not only to increase the heat transfer efficiency in the flat part, but also to increase the amount of air passing through the louver part, which has high heat exchange performance, and improve the heat radiation efficiency. It is characterized by having an uneven flat part between them.

[Effect]

According to the present invention, the conventionally flat portion between the louver portion and the flat tube becomes uneven, which not only increases heat transfer efficiency and improves heat exchange performance in this portion, but also improves air resistance. As a result, the amount of air flowing into the louver portion can be increased, and the heat dissipation function of the louver can be fully demonstrated. Furthermore, since the flat portion becomes uneven, the rigidity of the fin increases.

[Embodiments of the invention]

Hereinafter, regarding the present invention, the first embodiment shown in FIGS. 1 to 7 will be explained.
This will be explained based on an example.

FIG. 4 shows the entire heat exchanger. Reference numerals 1 and 2 are upper and lower brackets, respectively, and a flat tube 3 is stretched between the brackets 1 and 2 in a meandering manner. Corrugated fins 4 are interposed between the meandering flat tubes 3, and the bent portions of the corrugated fins 4 are joined to the side surfaces of the flat tubes 3. One end of the flat tube 3 is connected to the inlet body 5, and the other end is connected to the outlet body 6. In addition, in Figure 4, 7...
The mounting bracket is for.

As shown in FIG. 1, the corrugated fin 4 is formed by cutting and raising louvers 8 on a plate portion formed between bent portions. These louvers 8... are formed along the air flow direction in the center portion of the plate portion of the corrugated fin 4 between the flat tubes 3.3, and as shown in cross section in FIG. Center turning louver 8b
Louver 8a located on the upstream side in the air flow direction with
... and the louvers 8c located on the downstream side are formed so that their inclination directions are different from each other.

The bent portion of the corrugated fin 4 is the flat tube 3
, 3 by brazing or soldering, and a flat portion 9.9 is formed between this joint portion and the louver 8.

In this embodiment, an uneven surface of 10° IO is formed on this flat portion 9.9. The uneven surface IO is integrally molded by pressing the flat part 9. For example, as shown in FIG. It was formed in

Note that the uneven surface lO of the flat portion 9 can be molded at the same time as the louvers 8 .

That is, conventionally, the corrugated fin 4 has been obtained by forming the fin component plate 4 into a corrugated shape by passing it between a pair of gear-shaped forming tools 20 and 21, as shown in FIG. Cut and raised teeth 23, as shown in FIG. At the same time that the waveform is imparted by passing through the material, the louver 8 is simultaneously processed by the above-mentioned cutting and raising process 23.

To form the uneven surface 10, the gear-shaped forming tool 20 is
．． By forming an uneven molded surface 24 on the sides of the cut and raised teeth 23 formed on the tooth surfaces of the fins 21, the fin constituent plate material 4 is given a wave-like shape, and the louver 8 is formed. At the same time, the uneven surface IO can also be processed.

According to the embodiment having such a configuration, the refrigerant and hot water passing through the refrigerant passage 11 in the flat tube 3 exchange heat with the fins 4 through the wall of the flat tube 3.

The fins 4 exchange heat with the air flowing over their surfaces. In this case, the louvers 8 formed on the fins 4 increase the heat transfer coefficient with the air and increase the ventilation resistance, thereby increasing the efficiency of heat exchange with the air.

Moreover, since the uneven surface 10 is formed on the flat part 9 between the louvers 8 and the flat tube 3, the heat transfer coefficient of the flat part 9 increases and the heat transfer efficiency of the entire fin 4 is increased. This not only increases the exchange efficiency, but also increases the flow resistance of the cooling air flowing along the flat part 9.
directs the cooling air toward the louver 8. Therefore, the amount of air flowing through the louvers 8, which have high heat dissipation performance, increases, and the heat exchange efficiency improves.

Further, the uneven surface 10 formed on the flat portion 9 increases the mechanical strength of the flat portion 9.

Note that FIG. 7 shows the results of comparing the performance of a conventional fin in which no uneven surface is formed on the flat portion 9 and the fin 4 of the present invention in which an uneven surface 10 is formed. It can be seen that the fin 4 of the present invention in which the flat portion 9 has an uneven surface 10 has an excellent heat exchange function.

In the first embodiment, the uneven surface 10 of the flat portion 9 was formed by triangular peaks LOa and valleys 10b. As shown in the embodiment, the uneven surface 10 has round peaks 30a...
and valleys 30b... may be formed into a wave shape.

Further, the fins 4 are not limited to corrugated fins, but may also be plate fins.

〔Effect of the invention〕

As explained above, according to the present invention, the conventionally flat part between the louver part and the flat tube becomes uneven, which increases heat transfer efficiency and improves heat exchange performance in this part. In addition, the air resistance increases and the amount of air flowing into the louver portion increases, allowing the louver to fully demonstrate its heat dissipation function. Furthermore, since the flat portion becomes uneven, there is an effect that the rigidity of the fin is increased.

[Brief explanation of the drawing]

1 to 7 show a first embodiment of the present invention, FIG. 1 is an enlarged perspective view of a part of FIG. 4, and FIGS. 2 and 3 are parts of FIG. 1, respectively. 4 is a front view of the entire heat exchanger, 5 and 6 are diagrams explaining the corrugate fin manufacturing equipment, and 7 is a heat exchanger. A characteristic diagram showing efficiency, FIG. 8, is a sectional view of a portion corresponding to FIG. 3 showing a second embodiment of the present invention. 3... Flat tube, 4... Corrugated fin, 8
... Louver, 9 ... Flat part, 10 ... Uneven surface. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] In a heat exchanger in which a core part is formed by joining corrugated fins or plate fins having a plurality of louvers to a flat tube through which liquid flows, an uneven surface is formed on the flat part of the fin between the louver part and the flat tube. A heat exchanger characterized in that: