JPH0612218B2 - Heat exchanger manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a heat exchanger, and more specifically, as a condenser, an evaporator, an oil cooler or a radiator in an industrial machine or an air conditioner for an automobile. It relates to a suitable method for manufacturing a heat exchanger whose material is aluminum.

[Prior Art] Conventionally, heat exchangers A1 to A5 as shown in FIGS. 4 to 8 have been used as condensers, evaporators, oil coolers or radiators in industrial machines and air conditioners for automobiles. Of these, the heat exchanger A shown in FIG.
Reference numeral 1 denotes a condenser, which connects a refrigerant inlet 1a and an outlet 1b to a tube body B1 bent in a meandering shape, and further combines a heat-dissipating corrugated fin C1 formed from a brazing sheet in a heating furnace. It was brazed and integrated. One or a plurality of refrigerant passages 4b are formed in the tube body B1 as shown in the cross section of FIG. The brazing sheet has a thickness of 0.1.
It is a plate material of an aluminum alloy system of about 6 to 0.20 mm, and has a lower melting point than that on the surface of the core material alloy, for example, A
It is a coating of 1-Si based braze alloy. Then, brazing is performed by melting the brazing alloy on the surface of the brazing sheet in a heating furnace.

Further, the heat exchanger A2 in FIG. 5 is an evaporator, which is similar to the above-mentioned condenser in that the tube body B2 and the corrugated fin C2 are joined together, and the refrigerant body inlet 2a and outlet 2b are connected to the tube body B2. It is a thing. The heat exchanger A3 shown in FIG. 6 is also an evaporator, which is formed by stacking core plates B3 having cavities through which the refrigerant passes, joining corrugated fins C3, and further introducing an inlet 3a and an outlet of the refrigerant to the core plate B3. 3b is connected. The heat exchanger A4 in FIG. 7 is an oil cooler, which uses a straight pipe B4 instead of the meanderingly bent pipe body B1, and has a corrugated fin C4 and a liquid quality D in the straight pipe.
4 is joined, and the refrigerant inlet 4a and outlet 4b are connected to the liquid chamber D4. The heat exchanger A5 shown in FIG.
It is a radiator, which, like the oil cooler above,
The straight pipe B5, the corrugated fin C5, and the liquid chamber D5 are joined, and the inlet 5a and the outlet 5b of the cooling water are further connected.

That is, the manufacturing method of these heat exchangers A1 to A5 is
As described above, a brazing sheet is used as a material for the corrugated fins C1 to C5, and after each member is assembled, the brazing sheet is placed in a heating furnace and heated to melt the coating alloy on the surface of the brazing sheet so that other members can be melted. It was something that was brazed with and integrated.

[Problems to be Solved by the Invention] However, in the production of the heat exchangers A1 to A5, a thin brazing sheet is used as the corrugated fins C1 to C5 for the purpose of reducing weight and reducing material and production costs. Then, for example, as shown in the enlarged cross-sectional view of FIG. 10, when the fillet E6 is formed and the corrugated fin C6 is brazed to the tubular body 6, the Al-Si based braze alloy coated on the surface of the brazing sheet. The core material alloy is eroded by the corrugated fin C
There is a fatal defect that 6 buckles as shown. That is, attempts to reduce the thickness of the brazing sheet as the material of the corrugated fin C6 were naturally limited. Then, as a method for solving the problem, there has been proposed a method of applying an adhesive and then joining after assembling the heat exchanger (see Japanese Patent Laid-Open No. 61-41777). Based on the above, another method was invented.

[Means for Solving the Problems] That is, in the present invention, in manufacturing a heat exchanger, a core plate having a tube body having a refrigerant passage or a cavity serving as a refrigerant passage, and a tube body or a core plate A step of solvent degreasing a heat exchanger core composed of a corrugated fin provided on the surface before and after assembling, and a contact portion between the corrugated fin and the tubular body or core plate of the assembled heat exchanger core. Except for masking the side portion of the corrugated fin with a gap, and after applying a low-viscosity liquid adhesive by a spray method to the contact portion between the tubular body or core plate and the corrugated fin through the gap,
A step of blowing high-pressure air to remove excess adhesive around the bonded portion, and a step of putting the heat exchanger core formed in the above step in a curing oven to cure the adhesive in the bonded portion. The manufacturing method of the heat exchanger is

Here, as the tubular body, for example, a meandering bent one or a straight tube can be applied.

Further, as the material of the tube body, core plate or corrugated fin, for example, aluminum or its alloy can be used.

Further, the adhesive is made of Al having a particle size of 20 to 200 μm.
-Zn-based alloy, Cu, Ag or powder of the alloy is used for 3
It is desirable to contain -60%. This is because the above-mentioned powder and granules make the adhesion stronger and provide a cathodic corrosion protection effect at the bonded portion, and further, the contact heat resistance between the tube body or core plate and the corrugated fin is significantly reduced, resulting in good heat resistance. This is because it gives conductivity.

Furthermore, as the adhesive, for example, an epoxy-based, nylon-modified epoxy-based, nylon-based, nylon-epoxy-based, acrylic-based, nitrile-rubber-based, acryl-epoxy-based, etc. thermosetting adhesive is used. be able to.

The material of the corrugated fin is Al-Mn.
-Cu system, Al-Mn-Zn system, Al-Mn-Zn-S
n-based, Al-Mn-Zn-Cr-Zr-based, Al-Mn-
An Sn-based, Al-Mn-Zn-In-based, Al-Mg-based alloy, or the like can be applied.

[Operation] In the first step in the method for manufacturing the heat exchanger of the present invention,
A heat exchanger core composed of a pipe having a refrigerant passage or a core plate having a cavity to be the refrigerant passage, and a corrugated fin provided on the surface of the pipe or the core plate, Since the solvent degreasing is performed at a stage or after assembling, it has an action of removing the processing oil attached at the time of processing the parts, and has an action of increasing the adhesive strength by the adhesive described later.

In the next step, the sides of the corrugated fins are masked except for the contact portion between the corrugated fins and the tubular body or core plate of the assembled heat exchanger core, and the tubular body or core plate and corrugated fins are sprayed. Since the low-viscosity liquid adhesive is applied to the contacting portion with the adhesive, it is difficult for the adhesive to adhere to the masked portion and the corrugated fins are not clogged. And after applying the adhesive,
Since high-pressure air is blown, it has the function of removing the excess adhesive around the bonded portion.

In the next step, the heat exchanger core is put in a curing oven and heated to cure the adhesive, and the members of the heat exchanger are joined to each other to be manufactured.

By performing each of the above steps, it is possible to prevent clogging of the corrugated fins and excessive adhesion of the adhesive, thereby preventing the heat exchange efficiency from decreasing. Moreover, since the heat exchanger is manufactured without using a brazing sheet as a material for the corrugated fins, the corrugated fins can be made extremely thin.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view showing a manufacturing process of a heat exchanger (condenser) by the method of the present invention.

(A) Part manufacturing process First, a flat tube body 4 provided with a plurality (or one) of refrigerant passages 2 is bent by a known forming means to be formed into a meandering shape. The material of the tube body 4 is pure aluminum,
An Al-Mn-based alloy, an Al-Mn-Cu-based alloy, an Al-Cu-based alloy, or the like is used. Next, the corrugated fins 8 bent into a corrugated shape are formed from the coil material unwound from the original coil 6 of the thin aluminum sheet by known roll forming or press forming means. Examples of the thin aluminum sheet include an aluminum alloy bare material having a thickness of 0.03 to 0.13 mm.

(B) Assembly Step Next, the tube body 4 and the corrugated fins 8 are set in the shape of the heat exchanger core 14 by the assembly jig 12.

(C) Degreasing process Next, the solvent degreasing process of the assembled heat exchanger core 14 is performed. This solvent degreasing treatment is intended to remove the processing oil that has adhered during the processing of the parts, and thereby further enhances the adhesive strength of the adhesive described later. The solvent degreasing treatment liquid L used in this treatment is a treatment liquid generally used industrially, for example, 1.
1.1-Trichloroethane, trichloroethylene, perchlorethylene, trichlorotrifluoroethane, etc. are used. As a degreasing method, vapor degreasing is used in which the heat exchanger core 14 is placed on the shelf 16 having the through holes 16a provided in the steam tank 15, the degreasing solution is heated, and the steam is degreased. However, as another method, hot liquid immersion may be performed in which the liquid is directly immersed in the treatment liquid.

(D) Adhesive Coating Step Next, the solvent-degreased heat exchanger core 14 masks the side surface of the louver portion 17 of the corrugated fin 8 with a thin metal or plastic plate 18. The plate 18 used for this masking covers the central portion (louver portion 17) of the corrugated fin 8 having a normal height of about 16 to 19 mm by about 13 to 16 mm, and covers both ends of the corrugated fin 8, that is, both of the louver portions 17. Leave a gap in the outer part. This is the louver part 1 when spraying the adhesive.
By preventing unnecessary adhesive from adhering to 7,
This is to prevent clogging and prevent deterioration of heat exchange performance. After masking, a high-pressure spray method is used to spray a low-viscosity adhesive onto the adhesive portion 19 between the tubular body 4 and the corrugated fins 8 to evenly apply it, and then compressed air is blown to the adhesive portion 19 for extra adhesion. Remove the agent.

Examples of the type of the adhesive include thermosetting adhesives such as epoxy type, nylon-modified epoxy type, nylon type, nylon-epoxy type, acrylic type, nitrile-rubber type, and acrylic-epoxy type. . In this adhesive, an Al-Zn alloy (for example, American Aluminum Association standard AA7072 alloy) or Cu, Ag is used.
By containing the granular material made of the alloy and its alloy, the adhesive strength is increased, and the cathodic protection effect in the adhesive portion 19 is obtained, and further, the contact thermal resistance between the tubular body 4 and the corrugated fin 8 is significantly reduced, Good thermal conductivity is obtained. In particular, the particle size of the granules is 20-200 microns,
Preferably 3 to 60% of 50 to 100 microns,
When the content is preferably 10 to 50%, a heat exchanger excellent in both the adhesive strength, the cathodic protection effect and the thermal conductivity can be obtained.

(E) Connecting Member Connecting Step Next, the union 20 as a connecting member with another member is fitted to the tube body 4, and the adhesive in the syringe 22 is injected into the joint portion 24 to fill the adhesive.

(F) Heating Step Next, the heat exchanger core 14 thus formed is placed on the tray 26 and placed on the belt conveyor 30 running in the curing furnace 28, depending on the type of adhesive used. 80 ~
The adhesive is cured by heating in a temperature atmosphere of 200 ° C., and the tubular body 4, the corrugated fins 8, and the tubular body 4 and the union 20 are integrated.

(G) Coating Step Next, the taken out heat exchanger core 14 is painted and finished by a spray 32 as required to manufacture a desired heat exchanger.

As the shape of the corrugated fins 8, for example, various types that can be normally formed are applied as shown in a partially enlarged view of FIG. Among these, as shown in FIG. 2 (a), for example, there is one in which the adhesive portion between the U-shaped corrugated fin 8a and the tubular body 4a is surrounded by a fillet 34a.
As shown in FIG. 2 (b), a U-shaped corrugated fin 8
The apex of b is made flat, the flat surface 8bb and the tube body 4b are brought into close contact with each other, and the bonded portion is surrounded by the fillet 34b, or as shown in FIG. 2 (c), the corrugated fin 8c.
It is preferable that the flat surface 8cc and the tube body 4c are in close contact with each other and the bent portion is surrounded by the fillet 34c from the viewpoint of ensuring the adhesive strength and also from the viewpoint of heat exchange performance.

FIG. 3 is an explanatory view showing an embodiment of a manufacturing process of a laminated type heat exchanger according to the method of the present invention.

(A) Component manufacturing process First, a core plate 46 provided with a cavity 42 serving as a refrigerant passage and upper and lower communication ports 44a and 44b from an original coil 40 of a slightly thick aluminum sheet of 0.3 to 1.0 mm.
And the end plate 48 having the refrigerant inlet port 48a and the refrigerant outlet port 48b are formed by a known method (press working). Further, the corrugated fin 50 is formed in the same manner as in the first embodiment.

(B) Degreasing step Next, each molded member is placed in the liquid tank 52 containing the same degreasing agent as in the first embodiment, and hot liquid degreasing is performed.

(C) Adhesive Applying Step Next, after applying an adhesive to the surfaces of the core plate 46 and the end plate 48 in contact with each other, the assembly jig 54 is used to
Corrugated fin 50, core plate 46 and end plate 48
Assemble. Thereafter, as in the case of the first embodiment, the louver portion 58 of the heat exchanger core 56 is masked, and the adhesive is sprayed by the spray method, and then high pressure air is sprayed to remove the excess adhesive. To do.

(D) Connecting Member Connecting Step Next, the connecting member 60 such as a pipe is fitted and the adhesive is injected into the fitting portion.

(E) Heating Step Next, the heat exchanger core 56 is put into the curing oven 62 to cure the adhesive.

(F) Coating Step Next, the heat exchanger core 56 is taken out and sprayed with paint to complete the heat exchanger. Next, an experimental example of the heat exchanger (vehicle condenser) of the first embodiment will be described.

In the experiment, the state of clogging, heat exchange performance, change in cost due to loss of adhesive, and increase in weight due to adhesive were examined in an example in which a heat exchanger was manufactured by masking and a comparative example in which no masking was performed. The results are shown in Table 1 below.

As is clear from Table 1, the present embodiment has a remarkable effect that the heat exchange performance is high, the cost increase due to the loss of the adhesive is small, and the weight increase due to the surplus adhesive is small. On the other hand, the comparative example cannot solve the problems of deterioration of heat exchange performance, loss of adhesive, and weight increase.

Manufacturing the heat exchanger as shown in the first and second embodiments has the following effects.

In the embodiment of the present invention, on the side portions of the corrugated fins 8 and 50, masking is performed with a gap so as to correspond to the contact portion (rooting portion) between the corrugated fins 8 and 50 and the tubular body 4 or the core plate 46. Since the adhesive is applied from the gap portion to the contact portion by the spray method, the adhesive is applied only to this contact portion, and the other portion, specifically, the louver portion from the center of the corrugated fins 8 and 50. It is possible to prevent the adhesive from being applied to 17, 58.

This can improve the most important heat exchange performance in the heat exchanger.

In other words, if the louver portions 17 and 58 are clogged with the adhesive, the turbulent flow effect of the louver portions 17 and 58 is impaired, and the overall heat exchange performance (heat exchange amount) is significantly reduced. In the example, there is no such clogging, so
High heat exchange performance can be secured. In particular,
In the case where the masking is applied, the heat exchange performance is improved by about 28% as compared with the case where the masking is not performed.

In addition, since the adhesive is used only in the necessary parts and it is not necessary to use an extra adhesive, it is possible to prevent an increase in manufacturing cost due to the loss of the adhesive. Specifically, it is possible to reduce costs by 1200 yen per unit and save resources.

Further, it is possible to prevent the weight of the heat exchanger from increasing due to the use of the extra adhesive. Specifically, 300 per unit
The weight of g can be reduced.

Further, in each of the embodiments, high pressure air is blown to remove excess adhesive around the adhesive portion, so clogging due to the adhesion of excess adhesive is prevented, and in this respect also the heat exchange performance is reduced. Can be prevented.

Moreover, since the adhesive is usually sprayed from one direction, the adhesive tends to be less on the opposite side.However, by spraying a high-pressure fly, the adhesive adhered to the contact part (from the spraying side to the opposite side) The amount can be made uniform and the joint strength of the heat exchanger can be improved.

Further, by blowing high-pressure air, the amount of adhesive at each contact portion of the corrugated fins 8 and 50 can be made uniform (uniform fillet).
Also in this respect, the joint strength of the heat exchanger can be improved.

Further, the following effects (1) to (4) are achieved.

Since the adhesive is applied by the spray method, the adhesive can be uniformly processed in a short time, whereby the manufacturing cost can be reduced.

Since the joining members 20 and 60 such as unions can be joined at the same time in the curing furnaces 28 and 62 when joining the tube body 4 or the core plate 46 and the corrugated fins 8 and 50, manufacturing is facilitated.

As the material of the corrugated fins 8 and 50, since the non-blazing sheet can be applied, the corrugated fins are not corroded by the brazing alloy. Therefore, even if the corrugated fins 8 and 50 are made very thin, Since the buckling does not occur, the weight of the heat exchanger can be reduced.

Further, as a material for the corrugated fins 8 and 50, Al-Mn-Cu-based, Al-Mn-Zn-based, and Al-Mn, which have not been conventionally used for corrosion by a brazing alloy, are used.
-Zn-Sn system, Al-Mn-Zn-Cr-Zr system, A
1-Mn-Sn system, Al-Mn-Zn-In system or Al
It is possible to use an extremely thin coil having high strength and high corrosion resistance, such as a Mg-based alloy, and by using these, further weight reduction and material cost reduction can be realized.

Compared with brazing in which high temperature heating (600 ° C.) is performed, low temperature heating (80 to 200 ° C.) for a short period of time is sufficient, which requires less electric power and can significantly reduce manufacturing cost.

The aluminum material used, including the corrugated fins 8 and 50, is the softening temperature of aluminum (usually 360 ° C).
Since the following treatment can be performed, the initial work hardening strength can be maintained, and therefore the rigidity and strength of the product are high.

Since the manufacturing equipment is simple and no special technology is required, manufacturing is easy.

It is not necessary to use an expensive material such as a brazing sheet, and the material cost can be reduced.

[Advantages of the Invention] As described above, according to the present invention, clogging of the corrugated fins due to the adhesive can be prevented, and thus the heat exchange performance is improved. Further, since the application of the adhesive at the contact portion can be made uniform, the bonding strength is improved. In addition, the corrugated fins can be made thin, and since no excess adhesive is attached, the weight can be reduced and the loss of adhesive can be reduced. In addition, since the adhesive can be cured by heating at a low temperature for a short time, the rigidity and strength of the product can be increased, and the power consumption during the manufacturing can be reduced, so that the manufacturing cost can be significantly reduced. Further, since it is not necessary to use an expensive material such as a brazing sheet, the material cost can be reduced, and the manufacturing facility and technology are advantageous in that the manufacturing is easy.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing process of the heat exchanger of this embodiment,
FIG. 2 is a sectional view showing a joined state of a tubular body and a corrugated fin, FIG. 3 is an explanatory view showing a manufacturing process of a heat exchanger using a core plate, and FIGS. 4 to 8 are explanatory views of a conventional example. FIG. 9 is a cross-sectional view of the tubular body, and FIG. 10 is an explanatory view showing the problems of the conventional example. 4 ... Tube 8,50 ... Corrugated fins 14,56 ... Heat exchanger core 17,58 ... Louver part 20 ... Union 28,62 ... Curing furnace 46 ... Core plate

Claims (1)

[Claims] 1. In manufacturing a heat exchanger, a core plate having a pipe body having a refrigerant passage or a cavity serving as a refrigerant passage, and a corrugated fin provided on a surface of the pipe body or the core plate are provided. A step of solvent degreasing the heat exchanger core before or after assembling, except for the contact portion between the corrugated fin and the tubular body or core plate of the assembled heat exchanger core described above. And masking, and after applying a low-viscosity liquid adhesive by a spray method to the contact portion between the tubular body or core plate and the corrugated fin through the gap,
A step of blowing high-pressure air to remove excess adhesive around the bonded portion, and a step of putting the heat exchanger core formed in the above step in a curing oven to cure the adhesive in the bonded portion. And a method for manufacturing a heat exchanger.