JP4257649B2 - Aluminum alloy fin material for heat exchangers with excellent Abeck resistance - Google Patents

Description

This invention relates to an aluminum alloy fin material used in the fins of the heat exchanger, to a heat exchanger use aluminum alloy fin material constituting the heat exchanger with tubes, etc. to form a color forming portion by Dolores processing.

When manufacturing the heat exchanger, the tube is inserted into the collar molding part formed on the fins, so that a large number of fins are stacked at a predetermined pitch interval, and the tubes are expanded to fix the tubes and fins. And what is assembling a heat exchanger is known (for example, patent document 1). That is, as shown in FIG. 3, the color molding part 31 is formed in the plate fin 30, and the tube 20 is inserted into the through hole 32 inside the color molding part 31. Thereafter, the laminated plate fin 30 and the tube 20 are fixed by expanding the tube 20.
By the way, in recent years, heat exchangers have also been miniaturized with the miniaturization of air conditioners, and as a result, the fin pitch of the heat exchanger has been reduced, the tube diameter has been reduced, and the fin pattern has been simplified. Further, as the cost reduction, the fin plate thickness has been reduced. In the past, the plate thickness was about 110 μm, but in recent years, the thickness has become 100 to 90 μm.
Japanese Patent Laid-Open No. 55-1702

However, the thinning of the fins is a factor that reduces the rigidity of the fins. Therefore, there is a problem that an Abeck phenomenon occurs in which the fin pitch of the heat exchanger using aluminum fins is disturbed as shown in FIG. As in the past, when the plate thickness exceeds 110 μm, the rigidity of the fin is so high that it is difficult for the occurrence of Abeck. However, when the thickness is less than 110 μm, particularly 100 μm or less, the rigidity of the fin is lowered and the Abeck tends to occur.
The Abeck phenomenon not only impairs the appearance of the heat exchanger, but also increases the ventilation resistance and leads to a decrease in the performance of the heat exchanger.

  The present invention has been made against the background of the above circumstances, and an object thereof is to provide an aluminum alloy fin material for a heat exchanger in which the above-mentioned Abeck phenomenon hardly occurs even when the thickness is reduced.

The inventors of the present invention have made researches to solve the above problems, and have focused on Cu and Mg contained in the fin material. That is, the addition of Cu and Mg increases the amount of work hardening, so by forming the color molded part, the color molded part is work hardened to increase the strength, and the strength of the color molded part exceeds the strength of the unmolded part. It will be. For this reason, a non-processed part with comparatively low strength bends at the time of pipe expansion, and Abeck occurs. In particular, when forming a color molding part on a fin material containing Cu and Mg by drawless processing, the vertical wall of the color molding part is markedly hardened by stress applied during the ironing process, and an Abeck occurs when the pipe is expanded. It becomes easy to do.
Therefore, in the present invention, the above-mentioned Abeck phenomenon is hardly caused by appropriately adjusting other components together with the contents of Cu and Mg.

That is, in order to solve the above-mentioned problems, among the aluminum alloy fin materials for heat exchangers excellent in the Abeck resistance of the present invention, the invention according to claim 1 is mass%, Si: 0.05 to 0.9%, Fe: 0.1-0.5%, Mn: 0.1-0.6%, Zr: 0.01-0.15%, Ti: 0.005-0.1%, and as impurities Cu: regulated to 0.025% or less, have a composition balance being Al and impurities, characterized in that, supplied for Dolores processing.

  The aluminum alloy fin material for a heat exchanger excellent in Abeck resistance according to claim 2 is characterized in that, in the invention according to claim 1, it is further controlled by mass% and Mg: 0.025% or less as an impurity. .

The invention of claim 3 heat exchanger use aluminum alloy fin material excellent in resistance to young couples of description is the invention according to claim 1 or 2, characterized in that the plate thickness is less than 0.11 mm.

  Below, the reason for limitation of the component prescribed | regulated by this invention is demonstrated. In addition, all content of each component is shown by the mass% (hereinafter, the same).

Si: 0.05-0.9%
In the alloy of the present invention, Si is contained as an impurity, but if it exceeds 0.9%, the alloy characteristics are impaired, so the upper limit is made 0.9%. Further, Si, which is an impurity, is allowed to be contained within a range that does not adversely affect the alloy according to the invention, and if the amount of impurities is controlled too strictly, the material cost increases, so the lower limit for Si is set to 0.05%. For the same reason as described above, the upper limit of the Si content is preferably 0.5%.

Fe: 0.1 to 0.5%
The Fe component dissolves in the alloy to improve the strength and corrosion resistance of the alloy, and has an equivalent effect of improving the formability. To obtain these effects, the content of 0.1% or more is necessary. On the other hand, if the content exceeds 0.5%, the corrosion resistance is lowered. Therefore, the Fe content is limited to 0.1 to 0.5%. For the same reason, it is desirable that the lower limit is 0.1% and the upper limit is 0.3%.

Mn: 0.1 to 0.6%
The Mn component dissolves in the alloy substrate and raises the recrystallization temperature of the alloy, strengthens the alloy, further contributes to refinement of crystal grains and improvement of formability, and adversely affects corrosion resistance. It has the effect of improving the corrosion resistance of the alloy by forming an Fe component and a compound. If its content is less than 0.1%, no effect is obtained on the above action, while if it exceeds 0.6%, a coarse compound precipitates and the moldability deteriorates. The content was determined to be 0.1 to 0.6%. For the same reason, it is desirable to set the lower limit to 0.2% and the upper limit to 0.4%.

Zr: 0.01 to 0.15%
The Zr component has an effect of further increasing the recrystallization temperature of the alloy to moderate the annealing softening curve of the cold-worked material and facilitating the H2n tempering treatment. However, if the Zr content is less than 0.01%, the above effect cannot be obtained sufficiently, so the content must be 0.01% or more. Moreover, even if the Zr content exceeds 0.15%, no further improvement in effect is seen in the above action, and it may be difficult to manufacture (in terms of quality stability), such as inhibiting castability. The upper limit was set as described above in consideration of economic reasons. For the same reason, it is desirable to set the lower limit to 0.01% and the upper limit to 0.05%.

Ti: 0.005 to 0.1%
The Ti component is effective in making the cast structure finer, and in order to obtain the effect sufficiently, it needs to be contained in an amount of 0.005% or more. On the other hand, if the content exceeds 0.1%, the formability deteriorates due to the formation of coarse crystals, so the Ti content was set to 0.005 to 0.1%.

Cu: 0.025% or less Cu is a component that makes work hardening remarkable. By limiting the Cu content in inevitable impurities to 0.025% or less, it is possible to keep the work hardening amount of the color molded portion low. It is possible to prevent the Abeck phenomenon when assembling the heat exchanger. For the same reason, it is desirable to further limit the Cu content to 0.02% or less. From the above points, it is desired to reduce the Cu content as much as possible. However, if the Cu content is regulated too low, the material cost increases and the industrial property is inferior, so 0.005% may be set as the lower limit.

Mg: 0.025% or less Mg, as well as Cu, is a component that increases work hardening. If desired, the amount of Mg in the inevitable impurities can be regulated to 0.025% or less together with Cu. By restricting the Mg content, it is possible to further reduce the work hardening amount of the color molded part and further prevent the Abeck phenomenon. For the same reason, it is desirable to further limit the Mg content to 0.02% or less. Also, the Mg content is desired to be as low as possible as in the case of Cu, but 0.005% may be set as the lower limit in consideration of industrial properties as in the case of Cu.

The fin material of the present invention is not limited to a specific plate thickness. However, since the Abek phenomenon tends to occur particularly at a thickness of less than 0.11 mm, the fin material is less than 0.11 mm (or even 0.1 mm). A particularly remarkable effect can be obtained with a thin plate having a thickness of the following. In the Dolores processing used in forming the color forming portion, since the particular ironing hardening amount at the time of processing is large, particularly remarkable effects in the fin material is subjected to Dolores processing is obtained.

  That is, according to the present invention, the work hardening is suppressed to a low level by regulating the Cu content (more desirably, the regulation of Cu and Mg amounts), and the difference in hardness between the processed part and the unprocessed part is reduced, resulting in the occurrence of the Abeck phenomenon To prevent as much as possible. According to the present invention, it is possible to obtain an aluminum alloy fin material for a heat exchanger that is excellent in Abek resistance, and will greatly contribute to the reduction of the Abeck phenomenon by thinning the fin material in the future.

Hereinafter, an embodiment of the present invention will be described.
The fin material of the present invention can be produced, for example, by a conventional method, and can be formed into a thin plate shape by preparing the composition of the present invention and performing casting, homogenization treatment, hot rolling, cold rolling and the like. Moreover, after preparing into this invention composition and making it a plate material by continuous casting rolling, it may be made into a thin plate shape through cold rolling. After that, for example, H26 refining is performed by heating to 200 to 350 ° C.
In addition, in the said manufacturing process, the content in particular is not limited as this invention, It can manufacture by a suitable process.
Aluminum alloy fin material that is adjusted to the present invention composition, Ru provided a color forming portion by Dolores processing.

FIG. 1 is a diagram illustrating a process of providing a color molding portion 4 on the fin material 1 of the present invention by drawless processing.
That is, pierce sparing is performed at a desired location on the fin material 1 for the color molding portion, and then the first and second ironing are performed to form the rough color portion 2. The collar rough portion 2 is further subjected to a flaring process to form a color molding portion 4 having a through hole 3.

As shown in FIG. 2, the plate fins 10 obtained through such molding are stacked in a large number so that the interval is regulated by the height of the collar molding portion 4, and the tube 20 is inserted into the through hole 3. . When fixing the tube 20, the tube 20 is shaped so that the outer diameter is slightly smaller than the inner diameter of the through hole 3, and the tube 20 is inserted into the through hole 3 of the stacked plate fins 10. The plate fin 10 and the tube 20 are fixed by expanding the diameter with a plug (not shown) or the like and pressing the outer peripheral portion of the tube 20 against the collar molding portion 4.
When the tube 20 is expanded, the plate fin 10 manufactured by the fin material of the present invention is less likely to cause an Abeck, and a heat exchanger in which the plate fins are stacked in order with a predetermined interval is obtained.

After hot rolling the aluminum alloy ingot having the composition shown in Table 1 (remainder: Al and other impurities) under normal conditions to form a hot-rolled sheet, it is cold at a rolling reduction of 60 to 99%. A thin plate having a thickness of 0.1 mm was formed by rolling, and an H26 tempered material was produced by tempering annealing at a temperature of 275 ° C. for 6 hours. After that, fin press processing is performed under the conditions of fin inner diameter φ3 / 8, φ5 / 16 inch, fin pitch 1.1-1.8mm by drawless processing method, heat exchanger is manufactured for the pressed fin, and tube expansion test Pipe expansion evaluation was performed on the machine.
Moreover, the Vickers hardness of the fin collar cross section was measured about the fin after press work, and the hardness of the color molding part and the work hardening amount were compared. The results are shown in Table 2.
For tube expansion evaluation, we observed the occurrence of Abeck in the heat exchanger after tube expansion. . The results are shown in Table 2.

As can be seen from Table 2, the present invention example can eliminate the occurrence of Abeck by reducing the amount of Cu and Mg, and this reduces the so-called work hardening amount in which the hardness of the fin collar molding portion is reduced. It is because.
On the other hand, with respect to the composition outside the range of the present invention, Abeck occurred, the hardness of the fin collar molding part was high, and thus the work hardening amount also increased.

It is a figure which shows the drawless processing process using the fin material of this invention. Similarly, it is a figure which shows the assembly | attachment of the fin produced with the fin material of this invention, and a tube. It is a figure which shows the state which the Abeck phenomenon generate | occur | produced by the assembly | attachment of the fin produced with the conventional fin material, and a tube.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fin material 2 Color rough part 3 Through-hole 4 Color molding part 10 Plate fin 20 Tube

Claims (3)

In mass%, Si: 0.05 to 0.9%, Fe: 0.1 to 0.5%, Mn: 0.1 to 0.6%, Zr: 0.01 to 0.15%, Ti: with containing 0.005 to 0.1%, Cu as an impurity: restricted to 0.025% or less, characterized in that the remainder have a composition of Al and impurities, is subjected to Dolores machining An aluminum alloy fin material for heat exchangers with excellent resistance to Abeck.   The aluminum alloy fin material for heat exchangers with excellent Abeck resistance according to claim 1, further comprising, by mass%, Mg: 0.025% or less as an impurity. Heat exchanger use aluminum alloy fin material having excellent young couples of claim 1 or 2, wherein the thickness is less than 0.11 mm.

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