JP2010197002A - Tube for plate bending-type aluminum heat exchanger, aluminum heat exchanger, and method of manufacturing tube for plate bending-type aluminum heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tube for the plate bending-type aluminum heat exchanger capable of reducing defective brazing at a joining section of a surface of a sacrificial anode material and a surface of brazing filler metal. <P>SOLUTION: A groove 13 extending in the direction not in parallel with a threading direction in manufacturing the tube for the aluminum heat exchanger, that is, in the direction intersecting with the threading direction in manufacturing the tube for the aluminum heat exchanger, is formed, thus the flux can easily flow to the joining section of the sacrificial anode material not exposed to the external of a center pillar section and the like, and the brazing filler metal while guided by the groove 13, and the brazing performance can be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plate folding type aluminum heat exchanger tube, an aluminum heat exchanger, and a method for manufacturing a plate folding type aluminum heat exchanger tube, and more particularly to an automotive heat exchanger such as a radiator and a condenser. The present invention relates to a plate folding type aluminum heat exchanger tube using an aluminum alloy brazing sheet suitably used as a tube material, an aluminum heat exchanger and a plate folding type aluminum heat exchanger tube manufacturing method.

Aluminum alloys are lightweight and have high thermal conductivity, and are therefore used in automotive heat exchangers such as radiators, condensers, evaporators, heaters, and intercoolers. Automotive heat exchangers are mainly manufactured by the brazing method. Usually, brazing is performed at a high temperature of about 600 ° C. using a brazing material of an Al—Si alloy.
Although there are various brazing methods, the NB method of brazing in N ₂ gas using a fluoride-based flux that is a non-corrosive flux is generally used. Examples of the brazing alloy used in the NB method include Al—Si based brazing materials such as JIS 4343 alloy, JIS 4045 alloy, and JIS 4047 alloy.

  A heat exchanger 1 made of aluminum alloy such as a radiator manufactured using brazing integrally forms fins 3 processed into a corrugated shape between a plurality of flat tubes 2 as shown in FIG. Both ends of the tube 2 are opened in spaces formed by the plate 4 and the tank 5, respectively, and the flat tube 2 and the tank 5 form a cooling water circulation path structure. Here, as the flat tube 2, for example, as shown in FIG. 7, a plate-folded B-type tube 2 in which a plate material 6 is processed into a substantially B-shaped cross section by roll forming or the like may be used.

When the B-type tube 2 is used, as shown in FIG. 8, a joint portion 9 between a region 7 b that is not exposed outside the surface of the sacrificial anode material 7 and a region 8 b that is not exposed outside the surface of the brazing material 8 is formed. May exist. When the powder flux is attached to the heat exchanger component combined in such a manner, the flux cannot be allowed to flow into the regions 7b and 8b that are not exposed to the outside inside the width direction of the B-type tube 2, Flux does not adhere.
Therefore, the joint 9 between the region 7b not exposed to the outside of the sacrificial anode material surface 7 and the region 8b not exposed to the outside of the brazing material surface 8 lacks flux, which causes a defective brazing. ing.

  In Patent Document 1, an inner fin is disposed between a pair of plates, the plate and the inner fin are brazed and joined, and the outer peripheral edge of the pair of plates is brazed and joined to form a flat tube. With regard to aluminum alloy heat exchangers, a groove for holding flux is formed inside the tube, and at least in the groove part, it is possible to prevent the flux from falling off during parts conveyance, thereby preventing brazing defects. A brazing plate has been disclosed.

JP 2000-1441028 A

In the above-mentioned Patent Document 1, an inner fin is disposed between a pair of plates, and flux applied in advance for brazing and joining the plate and the inner fin is prevented from falling off during component conveyance.
Therefore, when brazing aluminum heat exchangers that do not have inner fins and apply flux after assembling, especially when heat exchangers using B-type tubes are brazed to the outside of the middle column brazing part, etc. It is not a measure to suppress the brazing failure of the joint between the surface of the sacrificial anode material not exposed and the surface of the brazing material.

  The present invention has been made to solve this problem, and is a plate folding type that can reduce the brazing failure of the joint between the sacrificial anode material surface and the brazing material surface that are not exposed to the outside. It aims at providing the manufacturing method of the tube for aluminum heat exchangers, the heat exchanger made from aluminum, and the plate for aluminum heat exchangers of a plate folding type.

  As a result of studying the above problems, the present inventors have found that a tube comprising a sacrificial anode material and an aluminum alloy brazing sheet having a specific alloy composition, and having a specific groove on at least one of the sacrificial anode material surface and the brazing material surface. Based on this finding, the present invention has been made.

  That is, the plate folding type aluminum heat exchanger tube of the present invention has an Al—Mn alloy or an Al—Mn—Cu alloy as a core material, and Si: 2 to 4% (mass%, hereinafter the same) on one surface , Zn: Cladded with an aluminum alloy sacrificial anode material containing 2 to 8%, the balance being Al and inevitable impurities, and clad an Al—Si or Al—Si—Zn alloy brazing material on the other surface The aluminum alloy brazing sheet is folded and the joint between the brazing material surface and the sacrificial anode material surface is joined by brazing, and at least one of the sacrificial anode material surface and the brazing material surface is passed through at the time of tube forming. It has a groove that is not parallel to the plate direction.

  The sacrificial anode material may further contain one or two of Mn: 1.8% or less, Ti: 0.25% or less, and Zr: 0.25% or less.

  The groove is preferably provided with a width of a surface opening of 0.5 mm or less, a depth of 20 μm or less, and an interval of 5 lines / cm or more.

  An aluminum heat exchanger can be configured using the plate folding type aluminum heat exchanger tube of the present invention.

  In addition, the method for producing a plate folding type aluminum heat exchanger tube according to the present invention has a joint portion between the brazing material surface and the sacrificial anode material surface, and the joining portion is joined by brazing that is not exposed to the outside. Using an Al-Mn alloy or Al-Mn-Cu alloy as the core material, Si: 2 to 4%, Zn: 2 to 8% on one side, the remainder being inevitable with Al An aluminum alloy brazing sheet clad with an aluminum alloy sacrificial anode material made of mechanical impurities and clad with an Al-Si or Al-Si-Zn alloy brazing material on the other surface, and the sacrificial anode material surface and brazing material surface On at least one of the surfaces, the width of the surface opening is 0.5 mm or less, the depth is 20 μm or less, and it is parallel to the sheet passing direction at the time of tube making at intervals of 5 / cm or more. And providing a groove.

  According to the plate folding aluminum heat exchanger tube, the aluminum heat exchanger, and the plate folding aluminum heat exchanger tube manufacturing method of the present invention, the plate folding aluminum heat exchanger tube is arranged outside the plate folding aluminum heat exchanger tube. It is possible to reduce defective brazing at the joint between the sacrificial anode material surface and the brazing material surface that are not exposed. As a result, in the brazing of the heat exchanger, it is possible to reduce the defective rate of brazing, and it is possible to manufacture a heat exchanger having excellent corrosion resistance.

(A) A schematic plan view of a preferred embodiment of the plate-foldable aluminum heat exchanger tube of the present invention, (b) Another preferred embodiment of the plate-foldable aluminum heat exchanger tube of the present invention. (C) Plane schematic diagram of a plate-foldable aluminum heat exchanger tube of a comparative example, (d) Planar schematic diagram of a plate-foldable aluminum heat exchanger tube of another comparative example (A) Partial cross-sectional schematic diagram of a preferred embodiment of the plate-foldable aluminum heat exchanger tube of the present invention, (b) Other preferred embodiment of the plate-foldable aluminum heat exchanger tube of the present invention Partial sectional schematic diagram of The partial perspective view of test TP used in the example of the present invention The perspective view of test TP used in the Example of this invention (A) Cross-sectional view of the test TP used in the example of the present invention, (b) Other cross-sectional view of the test TP used in the example of the present invention Disassembled perspective view of aluminum alloy heat exchanger Partially exploded perspective view of aluminum alloy heat exchanger Partial sectional view of aluminum alloy heat exchanger

A preferred embodiment of the plate folding type aluminum heat exchanger tube of the present invention will be described in detail.
The plate-folding aluminum heat exchanger tube 2 of the present invention comprises a brazing material 8 surface 11 of a brazing sheet 10 and a sacrificial anode material as shown in FIG. 1 (a) (b) or FIG. 2 (a) (b). 7 At least one of the surfaces 12 has various grooves 13 that are not parallel to the plate passing direction when the tube 2 for aluminum heat exchanger is formed.

  The groove processing on the surface of the sacrificial anode material 7 or the brazing material 8 of the brazing sheet 10 shown in FIG. 1 is a tube for an aluminum heat exchanger in which the sacrificial anode material 7 surface 12a or the brazing material 8 surface 11a shown in FIG. Corresponding to the plate-passing direction at the time of 2 pipe making and the 90 ° direction, the sacrificial anode material 7 surface 12b or the brazing material 8 surface 11b shown in FIG. 1 (b) is passed through the aluminum heat exchanger tube 2 And 45 ° direction.

  In this way, by adding a groove 13 extending in a direction that is not parallel to the plate passing direction when forming the aluminum heat exchanger tube 2 and thus intersecting the plate passing direction when forming the aluminum heat exchanger tube 2 is formed. The flux is easily guided by the groove 13 to the joint portion 9 between the sacrificial anode material 7 and the brazing material 8 which is not exposed to the outside such as the column portion 14 and the brazing property can be improved. Here, as shown in FIG. 7 and FIG. 8, the middle column portion 14 is a pair of hollow portions that are not opened to the outside when the aluminum heat exchanger tube 2 is formed from the brazing sheet 10 in a plate folding manner. It is a part formed in the intermediate position of a pair of hollow part as a boundary part.

If the groove 13 is parallel to the sheet passing direction when the aluminum heat exchanger tube 2 is formed, the flux flows into the joint portion 9 between the sacrificial anode material 7 and the brazing material 8 which are not exposed to the outside, such as the middle column portion 14. Effect is not obtained. If the groove 13 is not parallel to the sheet passing direction when forming the aluminum heat exchanger tube 2, the flux inflow effect can be obtained. However, the groove 13 is preferably a groove 13 that extends in a direction intersecting the 90 ° direction with the plate-passing direction when the aluminum heat exchanger tube 2 is formed.

By making the groove 13 extending in the direction intersecting the 90 ° direction with the sheet passing direction when the aluminum heat exchanger tube 2 is formed, the point where the groove 13 and the outer fin 3 intersect can be minimized. In this way, by minimizing the point where the groove 13 and the outer fin 3 intersect, when there are too many points where the groove 13 and the outer fin 3 intersect, much of the flux is used for external fillet formation. The problem that it is difficult to contribute to the formation of fillets on the inside can be solved.

The groove 13 may be processed by either the rolling process of the brazing sheet 10 or the pipe forming process of the aluminum heat exchanger tube 2. Moreover, although the processing method of the groove | channel 13 has roll processing, press processing, etc., it does not restrict | limit in particular. Moreover, you may change the length of the groove | channel 13, and the position which attaches the groove | channel 13 according to the joining shape of the tube 2 for aluminum heat exchangers.

Next, the reason and range of addition of the component elements of the aluminum alloy sacrificial anode material used in the plate folding type aluminum heat exchanger tube 2 of the present invention will be described.
Si: Si has an effect of lowering the melting point and improving brazing properties. The Si content is in the range of 2 to 4%. If the content is less than 2%, the effect is small. If the content exceeds 4%, the melting point becomes too low and the material is melted to deteriorate the function as a sacrificial anode material.

Zn: Zn has the effect of improving the corrosion resistance by lowering the potential of the sacrificial anode material and increasing the potential difference from the core material. The Zn content is in the range of 2% to 8%. If the content is less than 2%, the effect is small. If the content is 8% or more, the potential becomes too low, the sacrificial anode material is worn out early, and the corrosion resistance decreases.
Mn: Mn has the effect of increasing strength and improving corrosion resistance. The Mn content is 1.8% or less, and if it exceeds 1.8%, a coarse primary crystal Al ₆ Mn compound is produced at the time of casting, resulting in deterioration of workability and corrosion resistance. A preferable range is 0.5 to 1.5%.

Ti: Ti has a high concentration region and a low concentration region alternately distributed in the plate thickness direction, and the low concentration layer corrodes preferentially, so that it becomes a layered corrosion form and progresses pitting corrosion in the plate thickness direction. It has a suppressing effect. The Ti content is 0.25% or less, and if it exceeds 0.25%, a coarse primary crystal Al ₃ Ti compound is produced at the time of casting, resulting in deterioration of workability and corrosion resistance. A preferable range is 0.1 to 0.2%.

Zr: Zr has the effect of increasing strength and improving corrosion resistance. The Zr content is 0.25% or less, and if it exceeds 0.25%, a coarse primary crystal Al ₃ Zr compound is produced at the time of casting, resulting in deterioration of workability and corrosion resistance. A preferable range is 0.05 to 0.15%.
The clad thickness of the sacrificial anode material is not particularly limited, but a preferable range is 20 μm to 60 μm.
As the core material, an Al—Mn alloy or an Al—Mn—Cu alloy is used, but Si, Mg, Ti, or Zr may be added as necessary.

As the brazing material, an Al—Si based alloy or an Al—Si—Zn based alloy is used, but Mn, Fe, Ti, or Zr may be added as necessary. The clad thickness of the brazing material is not particularly limited, but a preferable range is 20 μm to 60 μm.
The surface of the sacrificial anode material 7 is not limited to the outer side and the inner side of the aluminum heat exchanger tube 2. When internal corrosion resistance such as a radiator or a heater is required, the inner side is used as the surface of the sacrificial anode material 7, and a capacitor, When external corrosion resistance such as an evaporator is required, the outside air side may be the surface of the sacrificial anode material 7.

As shown in FIG. 2, the groove 13 is preferably provided with a width w of the surface opening of 0.5 mm or less, a depth d of 20 μm or less, and an interval of 5 lines / cm or more.
If it is less than 5 lines / cm, the effect of the flux flowing into the middle pillar portion 14 is small, and if the depth exceeds 20 μm, not only the flux but also the wax flows in a large amount, so that erosion occurs in the core material and the corrosion resistance decreases.
When the width of the surface opening exceeds 0.5 mm, the capillary force becomes difficult to work. As a result, the flux is difficult to flow, and the effect of the flux flowing into the middle column portion 14 cannot be obtained.

Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
A sacrificial anode material and a JIS 4045 alloy brazing material having the composition shown in Table 1 were each cast by die casting, each face was chamfered and finished, and rolled to a thickness of 9 mm by hot rolling at 450 ° C. Next, JIS3003 alloy was cast as a core material by die casting, subjected to a homogenization treatment at 600 ° C. × 3 h, and then face-finished to a thickness of 42 mm. Thereafter, a sacrificial anode material with a clad rate of 15% is combined on one side of the core material, and a brazing material is clad with a clad rate of 15% on the other surface, and crimped by hot rolling at 450 ° C., and 3 layers of 3 mm A clad brazing sheet 10 was obtained. After that, cold rolling was performed to obtain a 0.4 mm plate material, followed by intermediate annealing at 350 ° C. × 3 h, and cold rolling again to obtain a H14 tempered material having a plate thickness of 0.3 mm.

Next, the produced plate material was used as a test material, and the brazing property and corrosion resistance were evaluated by the following methods.
(1) Brazability:
In particular, as shown in FIGS. 1D and 1A, 1B, and 1C, the surface of the brazing material 10 of the 0.3 mm brazing sheet 10 is subjected to press work without pressing the groove. Flat plate samples 11a, 11b, 11c having various grooves 13 formed thereon were produced. In addition to the threading direction and 90 ° direction shown in FIG. 1C and the threading direction and 45 ° direction shown in FIG. The brazing material 8 surface 12 was prepared so as to correspond to the plate passing direction and the 0 ° direction at the time of forming the aluminum heat exchanger tube 2, that is, in parallel.

  3 using a W-shaped bent sample 10a having the outer shape shown in FIG. 3 in which various grooves 13 are formed on the surface 12 of the sacrificial anode material 7 by press working and a 0.3 mm brazing sheet 10 not particularly subjected to groove machining. A W-shaped bent sample 10a having the outer shape shown in FIG. In addition, as a mode of the groove processing on the surface of the sacrificial anode material 7, it is shown in FIG. 1 (c) other than the plate passing direction and 90 ° direction shown in FIG. 1 (a) and the plate passing direction and 45 ° direction shown in FIG. The groove 13 on the surface 12c of the sacrificial anode material 7 was prepared corresponding to the case where the groove plate 13 for aluminum heat exchanger tube 2 was formed at 0 ° direction, that is, parallel to the plate passing direction.

  Thereafter, as shown in FIG. 4, various combinations of the flat plate samples 11a, b, c, d and the W-shaped bent sample 10a (12a-d) are combined with the corrugated 3003 alloy fins 3, Attached test TP15 was prepared. At that time, as shown in FIGS. 5 (a) and 5 (b), the flat plate samples 11a, b, c, and d are joined to the brazing material 8 on the surface to be joined to the W-shaped sample 10a (12a to d), The sacrificial anode material 7 was used as the surface of the W-shaped bent sample 10a (12a to 12d) to be joined to the flat plate samples 11a, b, c, and d. Moreover, the sample joined to the fin 3 used the brazing material 8 for the surface joined to the fin 3. The brazing test TP15 thus produced is surrounded by the sacrificial anode material 7 of the sample 10a (12a to 12d) bent into a W shape and the brazing material 8 of the flat plate samples 11a, b, c, d. A region 20 in which only both end portions are open to the outside is formed.

As shown in FIG. 5A, 5 g / m ² of fluoride flux powder 16 is attached from the outside of the brazing test TP 15 so that it does not adhere to the inside of the region 20 and is heated in a heating furnace in a nitrogen gas atmosphere. After holding at a temperature of 250 ° C. for 10 min, brazing was held at a temperature of 590 ° C. for 3 min.
By attaching the fluoride flux from the outside as described above, the region 20 surrounded by the sacrificial anode material 7 and the brazing material 8 in the brazing test TP15 as shown in FIG. The fluoride flux does not directly adhere to the sacrificial anode material 7 and the brazing material 8 in FIG.

Thereafter, the sacrificial anode material 7 and the brazing material 8 in the region 20 not exposed to the outside of the flat plate samples 11a, b, c, d and the W-shaped bent sample 10a (12a-d) shown in FIG. The formation state of the fillet 17 at the joint was evaluated. The test for evaluation was repeated 3 times, and the average value of 3 times was evaluated. The evaluation of brazing is “◎” when the fillet 17 has a brazing rate of 95% or more with almost no brazing, “○” when the joining rate is 85% or more and less than 95%, and 85% when 70% or more. Less than 95% or less than 95% but with erosion of the core material, “△”, and less than 70% fillet 17 with insufficient brazing as “x” did.

(2) Corrosion resistance evaluation:
In order to evaluate the corrosion resistance of the sacrificial anode material after brazing heat at a temperature of 590 ° C. for 3 minutes, a sample was prepared in which the surface of the sacrificial anode material 7 was exposed and the end face and the surface of the brazing material 8 were sealed.
Evaluation of corrosion resistance on the outside air side was performed by performing a CASS test (JIS H8681) 500 h on a single plate, and then measuring the pitting corrosion depth from the surface of the sacrificial anode material 7 using an optical microscope by a focal depth method. When the maximum pitting depth is less than 150 μm, the external corrosion resistance is good “◯”, and when the maximum pitting depth is 150 μm or more, the external corrosion resistance is insufficient “x”.

In addition, the corrosion resistance evaluation assuming the inner side was performed by using an aqueous solution in which 10 ppm of Cu ²⁺ was added to ASTM standard solution (Cl ⁻ , SO ₄ ²⁻ , HCO ₃ ⁻ each 100 ppm), immersed at 88 ° C. for 8 hours, and room temperature Then, the pitting corrosion depth was measured by the depth of focus method from the surface of the sacrificial anode material 7 using an optical microscope after 30 hours of immersion for 16 hours. When the maximum pitting depth is less than 150 μm, the internal corrosion resistance is good “◯”, and when the maximum pitting corrosion depth is 150 μm or more, the internal corrosion resistance is insufficient “x”.
The evaluation results of the above brazing properties are shown in Table 2, and the evaluation results of corrosion resistance are shown in Table 3.

  As is apparent from Table 2, the test material No. 1 to 19 have good formation of the fillet 17. In particular, the test material No. corresponding to the case where the groove 13 is provided on either the surface of the sacrificial anode material 7 or the surface of the brazing material 8 in the 90 ° direction and the sheet passing direction when the aluminum heat exchanger tube 2 is formed. 1, 4, 5, 9, 11, 15, 18, and 19 were excellent in brazeability.

  On the other hand, the test material No. corresponding to the case where the groove 13 is provided on either the surface of the sacrificial anode material 7 or the surface of the brazing material 8 in the direction of the plate when forming the aluminum heat exchanger tube 2 and the direction of 45 °. . 20 and 21 were slightly superior in brazing. A test material No. corresponding to the case where grooves 13 are provided on the surface of the sacrificial anode material 7 in the 45 ° direction and the sheet passing direction when the aluminum heat exchanger tube 2 is formed. No. 22 has a deep groove, so that a high bonding rate was obtained, but erosion occurred in the core material along the groove due to the deep groove. The test material No. 1 was provided with grooves on the surface of the brazing material 8 having a width corresponding to the 45 ° direction and a width of 0.7 mm exceeding 0.5 mm at the time of forming the aluminum heat exchanger tube 2. No. 23 was the result that it was somewhat excellent in brazing property.

  Test material No. which is a comparative example corresponding to the case where the groove 13 is provided on either the surface of the sacrificial anode material 7 or the surface of the brazing material 8 in the direction parallel to the plate passing direction when forming the aluminum heat exchanger tube 2 . In 24 and 25, the flux inflow effect by the groove was not obtained, and the brazing property was insufficient. Further, the test material No. corresponding to the case where the groove 13 is provided on the surface of the sacrificial anode material 7 in the 90 ° direction and the sheet passing direction when the tube 2 for aluminum heat exchanger is formed. In No. 26, the flux inflow effect by the groove was obtained, but since the amount of Si in the sacrificial anode material was less than 2% using the comparative brazing sheet H, the effect of improving brazing was not obtained.

  As is apparent from Table 3, the test material No. Nos. 25 to 31 were excellent both in the outside air side corrosion resistance and the internal corrosion resistance. On the other hand, test material No. which is a comparative example. Although 32 is excellent in corrosion resistance, it is inferior in brazing as described above, and thus the object of the present invention cannot be achieved. In addition, NO. In No. 33, the amount of Si was more than 4% and 5%, so the sacrificial anode material was melted and the corrosion resistance was lowered. No. No. 34 is inferior in corrosion resistance due to the small amount of Zn, so that the sacrificial anode effect is not obtained. No. 35 has too much Zn content, so that the sacrificial anode material was quickly worn out and inferior in corrosion resistance. No. Since 36-38 had many amounts of Mn, Ti, and Zr, the coarse intermetallic compound existed and it was inferior to corrosion resistance.

DESCRIPTION OF SYMBOLS 1 ... Aluminum alloy heat exchanger, 2 ... Aluminum heat exchanger tube, 3 ... Outer fin, 7 ... Sacrificial anode material, 8 ... Brazing material, 9 ... Joining part DESCRIPTION OF SYMBOLS 10 ... Brazing sheet, 11a, b, c, d ... Flat plate sample, 10a (12a-d) ... W-shaped bending sample, 13 ... Groove,
15 ... TP for brazing test, 17 ... fillet.

Claims (5)

An Al—Mn alloy or an Al—Mn—Cu alloy is used as a core material, and Si: 2 to 4%, Zn: 2 to 8% (mass%, hereinafter the same) is contained on one side, and the remainder is inevitable with Al. An aluminum alloy sacrificial anode material made of impurities is clad, and an aluminum alloy brazing sheet clad with an Al—Si or Al—Si—Zn alloy brazing material on the other surface is folded, and the surface of the brazing material 8 and the sacrificial anode material The joint with the surface is joined by brazing, and at least one of the surface of the sacrificial anode material and the surface of the brazing material 8 has a groove that is not parallel to the plate passing direction when forming the tube for the aluminum heat exchanger. A plate-foldable aluminum heat exchanger tube. The sacrificial anode material further contains one or two of Mn: 1.8% or less, Ti: 0.25% or less, and Zr: 0.25% or less. Plate folding aluminum heat exchanger tube. 3. The plate bending according to claim 1, wherein the groove has a width of a surface opening of 0.5 mm or less, a depth of 20 μm or less, and an interval of 5 / cm or more. Type aluminum heat exchanger tube. An aluminum heat exchanger comprising the plate-foldable aluminum heat exchanger tube according to any one of claims 1 to 3. An Al-Mn alloy having a joint between a brazing material surface and a sacrificial anode material surface and using a plate-folding aluminum heat exchanger tube joined by brazing that the joint is not exposed to the outside. Alternatively, an Al-Mn-Cu alloy is used as a core material, and Si: 2 to 4%, Zn: 2 to 8% is contained on one surface, and an aluminum alloy sacrificial anode material composed of the remaining Al and inevitable impurities is clad, An aluminum alloy brazing sheet clad with an Al—Si-based or Al—Si—Zn-based alloy brazing material on the other surface is used, and a surface opening is formed on at least one of the sacrificial anode material surface and the brazing material surface. A groove having a width of 0.5 mm or less, a depth of 20 μm or less, and an interval of 5 pieces / cm or more is provided that is not parallel to the plate passing direction when forming a tube for an aluminum heat exchanger. Plate folding type method for producing an aluminum heat exchanger tube to be.

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