CN1781009A - Evaporator and its manufacturing method - Google Patents

Abstract

The present invention discloses an evaporator 1 comprises a flat tube 2 bent zigzag, and a corrugated fin 3 disposed between each adjacent pair of straight tube portions 2 a of the flat tube 2 and brazed thereto by the flux brazing method. The flux remains on the surface of the portion of the corrugated fin 3 not brazed to the straight tube portions 2 a in an amount of 0.03 to 1 g/m<SUP>2. </SUP>. The evaporator 1 is fabricated by a process including applying the flux in an amount of 0.05 to 2.8 g/m<SUP>2 </SUP>to the outer surface of a zigzag flat tube 2, disposing a corrugated fin 3 between each adjacent pair of straight tube portions 2 a of the flat tube 2 and brazing the fin 3 to the flat tube 2. The evaporator 1 can be effectively inhibited from emanating odor.

Description

Evaporator and its manufacturing method

Cross References to Related Applications

This application is an application filed under 35 U.S.C. § 111(a) and a provisional application filed under 35 U.S.C. § 111(b) under 35 U.S.C. § 111(b) under 35 U.S.C. § 119(e)(1) Priority filing date for No. 60/477,746.

technical field

The present invention relates to an evaporator and a method of manufacturing the same, and more particularly, to an evaporator for, for example, a motor vehicle air-conditioning apparatus in which a chlorofluorocarbon refrigerant or a CO ₂ refrigerant is used, and a method of manufacturing the same.

Background technique

Evaporators of the type comprising hollow bodies through which the refrigerant flows and corrugated fins (brazed) brazed on the outer surface of the adjacent hollow bodies are widely used.

This evaporator is manufactured by combining a hollow body through which the refrigerant circulates and corrugated fins, spraying a flux suspension prepared by suspending non-corrosive fluoride flux in water over the entire assembly, and The fins were brazed to the adjacent hollow body by heating the assembly in a nitrogen atmosphere.

However, the evaporator produced in this way inevitably leaves flux residues on the parts of the corrugated fins which are not brazed to the hollow body. It has been found that if the amount of flux residue remaining in the evaporator increases, the evaporator, when incorporated into a motor vehicle air conditioning unit, emits a strong (smelly) odor and can be uncomfortable for occupants in the motor vehicle cabin .

The amount of flux residue can be reduced by reducing the amount of flux in the suspension, but this can lead to defects in the soldered joint.

The evaporator described above includes a stacked plate type evaporator in which each hollow body through which the refrigerant flows includes two plates formed by brazing a brazing plate having layers of brazing material on both sides thereof and the circumference of which is formed by brazing. Brazed to each other towards the edge, the two plates define a protruding refrigerant channel and a protruding header formation communicating with each of the two ends of the channel, the hollow The bodies are stacked so that the outer surfaces of the header forming portions on each pair of adjacent hollow bodies are in contact with each other, and the corrugated fins are provided between the parts of the adjacent hollow bodies corresponding to their refrigerant passages and brazed on the hollow body. physically. In order to simplify or eliminate the step of rinsing off flux residues after brazing, it is known in the manufacture of said stacked evaporators to apply a relatively small amount of flux to the outer surfaces of the plates forming the hollow body through which the refrigerant flows, e.g. 3-7 g/m ² flux (see published document JP-A No. 2000-202620).

However, the evaporator manufactured by the method disclosed in the above publication still needs to be improved in completely reducing the odor emission caused by the flux residue.

An object of the present invention is to overcome the above-mentioned problems, and to provide an evaporator suitable for effectively suppressing odor emission and a method of manufacturing the evaporator.

Contents of the invention

In order to achieve the above objects, the present invention includes the following modes.

1) An evaporator comprising a hollow body through which a refrigerant circulates and fins brazed on the outer surface of the hollow body by a flux brazing method, flux residues on the surface of the portion of the fin not brazed to the hollow body The amount is 0.03-1 g/m ² .

2) The evaporator described in paragraph 1) above, wherein the amount of flux remaining on the surface of the portion of the fin that is not brazed to the hollow body is 0.05-0.5 g/m ² .

3) The evaporator described in the above paragraph 1), wherein the flux is a non-corrosive fluoride flux.

4) The evaporator described in the above paragraph 1), wherein the hollow body through which the refrigerant circulates comprises flat tubes bent in a zigzag shape, and the fins comprise corrugated brazing sheets with layers of brazing material on both sides thereof. Fins, the corrugated fins are arranged between each pair of adjacent straight tube portions of the zigzag flat tubes and brazed thereon.

5) The evaporator described in the above paragraph 1), the evaporator comprises a plurality of straight flat tubes each constituting a hollow body through which the refrigerant flows, and the fins are made of brazing sheet material with layers of brazing material on both sides thereof The plurality of flat tubes are arranged parallel to each other at intervals, and the corrugated fins are arranged between each pair of adjacent flat tubes and brazed thereon.

6) The evaporator described in the above paragraph 1), which comprises a plurality of hollow bodies in which the refrigerant circulates, each comprising two plates consisting of a brazing sheet material with layers of brazing material on both sides. formed and brazed to each other at their peripheral edge portions, the two plates define therebetween a raised refrigerant passage and a raised header communicating with each of the two ends of the refrigerant passage The fins include corrugated fins, the plurality of hollow bodies are stacked so that the outer surfaces of the header forming portions on each pair of adjacent hollow bodies contact each other, and the corrugated fins are arranged on each pair of adjacent hollow bodies. between the parts of the adjacent hollow body corresponding to the corresponding refrigerant passages and brazed to the hollow body.

7) The evaporator described in the above paragraph 1), which has been treated so as to have hydrophilicity.

8) A refrigerating cycle comprising a compressor, a condenser and an evaporator in which a chlorofluorocarbon refrigerant is used, the evaporator being the evaporator according to any one of 1 to 7 above.

9) A vehicle in which the refrigerating cycle described in the above paragraph 8) is installed as an air conditioner for a motor vehicle.

10) A method for manufacturing an evaporator, the method comprising: preparing a flat tube bent into a zigzag shape and having a refrigerant flow passage therein, and a fin made of a brazing sheet material having a brazing material layer on both sides thereof sheet, applying flux in an amount of 0.05-2.8 g/m ² on the outer surface of the zigzag flat tube, placing the fins between each pair of adjacent straight tube portions of the zigzag flat tube, and placing the fins Brazed on a Z-shaped flat tube.

11) The method for manufacturing an evaporator described in the above paragraph 10), wherein the amount of flux applied to the flat tube is 1-2 g/m ² .

12) A method for manufacturing an evaporator, the method comprising: preparing a plurality of straight flat tubes each having a refrigerant flow passage therein, and fins made of brazing sheet materials having brazing material layers on both sides thereof sheet, apply flux in an amount of 0.05-2.8 g/m ² on the outer surface of each flat tube, arrange the plurality of flat tubes in parallel at intervals from each other, and arrange fins on each pair of adjacent flat tubes between, and brazing the fins to the flat tubes.

13) The method for manufacturing an evaporator described in the above paragraph 12), wherein the amount of flux applied to the flat tube is 1-2 g/m ² .

14) A method for manufacturing an evaporator, the method comprising: preparing a plate and a fin made of a brazing sheet having a brazing material layer on both sides thereof, each having a channel forming protrusion and a collection a tube forming protrusion protruding to a greater extent than the channel forming part and extending from each of both ends of the channel forming part; flux is applied to both surfaces of each plate member, applying The amount of flux on the outer surface of the two protrusions of each plate is adjusted to 0.05-2.8g/m ² ; the plates are arranged into stacked pairs, each stacked pair includes a combination of two plates, wherein The openings of each kind of protrusions are opposed to each other in a corresponding relationship so that the outer surfaces of the bottom walls of the header forming protrusions on adjacent pairs of plates are in contact with each other, and the fins are arranged on each pair of adjacent plates. Between the parts corresponding to the passage forming protrusions of the plates; the two plates in each pair are brazed to each other along the peripheral edges to form a hollow body through which the refrigerant flows, and the fins are brazed together. Welded on corresponding adjacent pairs of hollow bodies.

15) The method for manufacturing an evaporator described in the above paragraph 14), wherein the amount of flux applied to the outer surfaces of the two kinds of protrusions per plate is 1-2 g/m ² .

16) The method for manufacturing an evaporator described in any one of the above paragraphs 10) to 15), wherein the flux is applied by being suspended in water containing a binder.

17) The method for manufacturing an evaporator described in any one of the above paragraphs 10) to 15), wherein corrugated fins are used as the fins.

18) The method for manufacturing an evaporator described in any one of the above paragraphs 10) to 15), wherein finally the brazed assembly is treated to make the assembly hydrophilic.

Under the evaporator described in the above paragraphs 1) and 4)-6), the amount of flux residue on the surface of the portion of the fin that is not brazed to the refrigerant circulation hollow body is 0.03-1 g/m ² , so that Effectively suppresses odor emission. Furthermore, the invention makes it possible to avoid defective soldered connections between the hollow body and the fins during the manufacture of the evaporator.

The evaporator described in the above paragraph 2) can suppress odor emission more effectively.

Under the method for manufacturing an evaporator described in paragraphs 10), 12) and 14), the amount of flux remaining on the surface of the part of the fin that is not brazed on the refrigerant circulation hollow body is 0.03-1 g/ m ² , which can effectively suppress odor emission. Furthermore, the invention makes it possible to avoid defective soldered connections between the hollow body and the fins during the manufacture of the evaporator.

Under the methods for manufacturing the evaporator described in paragraphs 11), 13) and 15), the manufactured evaporator can suppress odor emission more effectively.

Under the method for manufacturing an evaporator described in paragraph 16), the adhesive is used to prevent flux during assembly after the application of the flux and included in the methods described in paragraphs 10), 12) and 14). released or dropped.

Description of drawings

FIG. 1 is a perspective view showing an evaporator as a first embodiment of the present invention;

2 is a partial perspective view showing an evaporator as a second embodiment of the present invention;

Fig. 3 is a partially exploded perspective view showing a third embodiment as the present invention.

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the term "aluminum" includes aluminum alloys in addition to pure aluminum.

Figure 1 shows a first embodiment of an evaporator according to the invention.

Referring to Fig. 1, the evaporator 1 includes a flat tube (hollow body through which the refrigerant circulates) 2 made of extruded aluminum profiles and bent into a Z shape, and an aluminum brazing sheet made of brazing material layers on both sides. Corrugated louver-like corrugated fins 3 and two aluminum headers 4 brazed to both ends of the Z-shaped flat tube 2 .

The zigzag flat tube 2 is provided with vertically positioned straight tube portions 2a, and corrugated fins 3 are interposed between and brazed to each pair of adjacent straight tube portions 2a. The straight pipe portion 2a at each of both ends of the Z-shaped flat pipe 2 has corrugated fins 3A in the form of corrugated louvers on its outside and aluminum side plates 5 outside the fins 3A. 3A is made of an aluminum brazing sheet with layers of brazing material on both sides. The corrugated fins 3A are brazed to the straight pipe portion 2 a and the side plate 5 . Although not shown, there are a plurality of parallel refrigerant passages inside the zigzag flat tube 2 . The corrugated fins 3, 3A comprise parallel flat sections and curved sections interconnecting each pair of adjacent flat sections. The fins are brazed to the straight pipe portion 2a or the side plate 5 at the outer end portion of the bent portion.

The straight pipe portion 2a or the side plate 5 of the zigzag pipe 2 is brazed to the corrugated fin 3 or 3A by non-corrosive fluoride flux.

The amount of flux remaining on the surface of the portion of the corrugated fins 3, 3A that is not brazed on the straight pipe portion 2a or the side plate 5 (hereinafter referred to as "amount of flux residue") is 0.03-1 g/m ² . Such limitation on the amount of flux residue is made because if the amount is less than 0.03 g/m ² , the amount of flux used for brazing will be insufficient and defects may occur at the brazed joint, whereas if the amount exceeds 1 g/m m ² , the evaporator 1 will emit a strong odor. The amount of flux residue on the surface of the portion of the corrugated fin 3, 3A that is not brazed to the straight pipe portion 2a or the side plate 5 is preferably 0.05-0.5 g/m ² . The portion of the corrugated fins 3, 3A that is not brazed to the straight pipe portion 2a or the side plate 5 is the entire flat portion described above, and may include a part of the curved portion described above.

The evaporator 1 was manufactured by the following method.

First, a flat tube 2 made of extruded aluminum profile and bent into a Z-shape, a louver-like corrugated fin 3 made of brazing sheet material with layers of brazing material on both sides, and an aluminum side plate 5 are prepared. and two aluminum headers4. Then, flux is applied in an amount of 0.05-2.8 g/m ² on the outer surface of the zigzag flat tube 2 by a suitable method. This flux is used suspended in water containing a binder, and the amount of flux to be applied is that of the flux itself contained in the suspension. The amount of flux to be applied to the outer surface of the zigzag flat tube 2 is limited to 0.05-2.8 g/m ² because if the amount is less than 0.05 g/m ² , the amount of flux for brazing will be insufficient. , so that defects may occur at the brazed joints, and if the amount exceeds 2.8 g/m ² , the evaporator 1 will emit a strong odor. The amount of flux to be applied to the outer surface of the zigzag flat tube 2 is preferably 1-2 g/m ² .

Then, the corrugated fins 3 are arranged between each pair of adjacent straight pipe portions 2a of the zigzag pipe 2, and the remaining corrugated fins 3 are arranged outside the straight pipe portions 2a respectively located at both ends of the pipe. Headers 4 are connected to both ends of the tube 2, respectively. Secure the formed assembly with suitable fixtures.

Subsequently, the fixed assembly is heated at a predetermined temperature in a heating furnace having a nitrogen atmosphere to braze the straight tube portion 2a of the zigzag flat tube 2 to the side plates or corrugated fins 3, 3A, and the tube 2 is brazed on the two headers 4. In this way, the evaporator 1 is manufactured.

After the brazing operation, for example, the evaporator 1 is subjected to cleaning treatment, chemical conversion treatment, and treatment to make the assembly hydrophilic.

The cleaning treatment is performed by bringing the evaporator 1 into contact with an acid cleaning agent containing at least one of nitric acid, sulfuric acid, and hydrofluoric acid. The acid cleaner to be used is, for example, an acid cleaner containing 0.01-5% by mass of iron salt. Examples of usable iron salts are ferric sulfate, ferric nitrate, ferric acetate and ferric chloride. Preferably, the evaporator 1 is contacted with an acid cleaning agent at 10-85° C. for 30 seconds to 5 minutes for cleaning.

The chemical conversion treatment is carried out by forming a chemical conversion coating using a chromic acid or phosphoric acid chromating treatment agent, or using a chromium-free agent such as a zirconium treatment agent to form a chemical conversion coating. When using a zirconium treatment agent to form a chemical conversion coating, it must be cleaned with an acid cleaner containing iron salts.

The treatment of making the evaporator hydrophilic is carried out by using a reagent capable of imparting hydrophilic properties, said reagent containing finely divided carbon dioxide in a mass ratio of 30:70 to 70:30 and their combined amount being 0.2-25% by mass Silicon and vinyl alcohol polymers, wherein finely divided silica is dispersed in an aqueous medium in the form of microparticles coated with vinyl alcohol polymers, the coated particles having an average particle size of 5-1000 nm. The agent may comprise an odor suppressant comprising an organic compound having an amide group and/or a phenolic group. The agent may also contain an antibacterial or bactericidal agent.

In this way, the evaporator 1 can be provided with corrosion resistance or hydrophilicity.

Figure 2 shows a second embodiment of the evaporator of the invention. With reference to the second embodiment, the upper and lower parts, the left-hand side and the right-hand side of Fig. 2 will be referred to as "upper", "lower", "left" and "right", respectively, and the direction of air flow (i.e. arrows in Fig. 2 The way indicated by A) will be called "front", and the opposite direction will be called "rear".

Referring to Fig. 2, the evaporator 10 includes a pair of upper and lower aluminum headers 11, 12 spaced apart from each other, flat tube groups 14, 15 and corrugated fins 16 of corrugated louver type, the flat tube group is in the form of It is a flat tube (hollow body in which refrigerant circulates) 13 that is made of aluminum extruded profiles and arranged in parallel to the left or backward—that is, horizontally—with a certain interval. Aluminum brazing sheet with a layer of brazing material on one side. Each of the flat tubes 13 through which refrigerant flows has a plurality of parallel refrigerant passages.

The interior of the upper header 11 is divided into front and rear header chambers 11a, 11b by a partition wall 17 extending transversely. Within the flat tube groups 14 , 15 , the flat tubes 13 are arranged forward or backward in their width direction—that is, positioned in the transverse direction of the evaporator 10 . The upper ends of all the flat tubes 13 in the front tube group 14 are brazed to the upper header 11 so as to communicate with the front header chamber 11a, while the lower ends of the flat tubes 13 are brazed to the front of the lower header 12. part to communicate with the interior of the lower header. The upper ends of all the flat tubes 13 in the rear tube group 15 are brazed to the upper header 11 so as to communicate with the rear header chamber 11b, while the lower ends of the flat tubes 13 are brazed to the rear of the lower header 12. part to communicate with the interior of the lower header. Corrugated fins 16 are provided between and brazed to each pair of adjacent flat tubes 13 .

The flat tubes 13 through which the refrigerant flows are brazed to the corrugated fins 16 and the two headers 11 , 12 by means of a non-corrosive fluoride flux.

The amount of flux residue on the surface of the portion of the corrugated fin 16 that is not brazed to the flat tube 13 is 0.03-1 g/m ² , preferably 0.05-0.5 g/m ² . The reason for so limiting the amount of flux residue is the same as in the first embodiment described above. The portions of the corrugated fins 16 that are not brazed to the flat tube 13 are also the same as those described in the first embodiment.

The evaporator 10 is manufactured by the following method.

First, the flat tubes 13 through which the refrigerant flows made of aluminum extruded profiles, the louver-like corrugated fins 16 made of brazing sheets with layers of brazing material on both sides, and the upper and lower headers are prepared. 11, 12. Then, flux is applied to the outer surface of the flat tube 13 by a suitable method in an amount of 0.05-2.8 g/m ² , preferably 1-2 g/m ² . The flux is used suspended in water containing a binder, and the amount of flux to be applied is that of the flux itself contained in the suspension. The reason for the above limitation of the amount of flux to be applied on the outer surface of the flat tube 13 is the same as in the first embodiment.

Next, the flat tubes 13 are arranged in two rows one behind the other to form the flat tube groups 14 , 15 , and the corrugated fins 16 are arranged between each pair of adjacent flat tubes 13 . The ends of the flat tubes 13 are then placed into corresponding sockets (not shown) formed in the upper and lower headers 11, 12 and the assembly is secured with suitable clamps.

Subsequently, the fixed assembly is heated at a predetermined temperature in a heating furnace with a nitrogen atmosphere, thereby brazing the flat tubes 13 to the headers 11 , 12 and the corrugated fins 16 . In this way, the evaporator 10 is manufactured.

Figure 3 shows a third embodiment of the evaporator of the present invention.

Referring to Fig. 3, the evaporator 20 includes a plurality of flat hollow bodies (hollow bodies through which the refrigerant circulates) 21 arranged in parallel and welded to each other at the connected upper ends, and corrugated fins 22 of louver type. The fins 22 are made of aluminum bare material and are arranged between and brazed to each pair of adjacent flat hollow bodies 21. Refrigerant flowing into the evaporator through the fluid inlet 23 flows through all flat hollow bodies 21 and exits via the fluid outlet 24 .

Each flat hollow body 21 is formed from two plate parts 25 by brazing the two plate parts 25 to each other at their peripheral edge portions, said plate parts having brazes on both sides. Aluminum brazing sheet with brazing material layer. A U-shaped protruding refrigerant channel 26 and a header forming part 27 are defined between the two plates 25, and the height of the header forming part is larger than the protruding height of the channel 26 and is in line with the channel. Each of the two ends of 26 is connected. The hollow bodies 21 are stacked on each other and brazed to each other so that the outer surfaces of the header forming portions 27 on each pair of adjacent hollow bodies 21 are in contact with each other. The corrugated fins 22 are disposed between portions of adjacent hollow bodies corresponding to their corresponding refrigerant passages 26 , and are brazed to the hollow body 21 .

The above-mentioned plate parts 25 are brazed to each other and the flat hollow body 21 to the corrugated fins 22 using a non-corrosive fluoride flux.

The amount of flux residues on the surface of the part of the corrugated fin 22 which is not soldered to the flat hollow body 21 is 0.03-1 g/m ² , preferably 0.05-0.5 g/m ² . The reason for so limiting the amount of flux residue is the same as in the first embodiment described above. The parts of the corrugated fins 22 which are not brazed to the flat hollow body 21 are also the same as those described in the first embodiment.

The evaporator 20 is manufactured by the following method.

First, the plate member 25 and the corrugated fins 22 each having a channel-forming protrusion 25a and a header-forming protrusion having a U-shape as a whole are prepared using a brazing sheet material having layers of brazing material on both sides thereof. 25b, the header-forming protrusion 25b protrudes to a height greater than that of the channel-forming protrusion 25a and extends from each of both ends of the protrusion 25a.

Then, flux is applied on both surfaces of each plate 25 by a suitable method. At this time, 0.05-2.8 g/m 2 , preferably 1-2 g/ ^{m 2} of flux is applied to the outer surfaces of both protrusions 25 a, 25 b of the plate 25 . The flux is used suspended in water containing a binder, and the amount of flux to be applied is that of the flux itself contained in the suspension. The reason for the above limitation of the amount of flux to be applied to the outer surfaces of the two kinds of protrusions 25a, 25b is the same as that of the first embodiment.

Then, the plates 25 are arranged in stacked pairs, each stacked pair comprising a combination of two plates, wherein the openings of each protrusion 25a (25b) face each other in a corresponding relationship so that adjacent plates The outer surfaces of the bottom walls of the header forming projections 25b of the pair 25 are in contact with each other, and the corrugated fins 22 are provided between portions of each pair of adjacent plate members 25 corresponding to the channel forming projections 25a of the plate members. between. Secure the formed assembly using suitable fixtures.

Subsequently, the fixed assembly is heated at a predetermined temperature in a heating furnace with a nitrogen atmosphere to braze the two plate members of each pair to each other along the peripheral edge portions to form a flat hollow body, and to braze the fins. Welded on the corresponding pair of adjacent flat hollow bodies. In this way, the evaporator 20 is manufactured.

According to the second and third embodiments, the manufactured evaporator is subjected to cleaning treatment, chemical conversion treatment, and treatment to make components hydrophilic in the same manner as in the first embodiment.

The evaporators 1, 10, 20 of the first to third embodiments can form a refrigeration cycle in which a chlorofluorocarbon refrigerant is used together with a compressor, a condenser, and an expansion valve, and the refrigeration cycle is installed in a vehicle such as a motor vehicle. In order to be used as motor vehicle air conditioning equipment.

In addition, the evaporators 1, 10, 20 of the first to third embodiments can all form a refrigeration cycle in which CO ₂ refrigerant is used together with a compressor, a gas cooler, an intermediate heat exchanger, and an expansion valve, and the refrigeration cycle Installed in a vehicle such as a motor vehicle for use as a motor vehicle air conditioner.

Specific examples of the present invention will be described below together with comparative examples. An evaporator shaped as shown in FIG. 1 was used in these examples and comparative examples.

Example 1-4

A flux suspension comprising flux (FL-7, product of Morita Kagaku Co., Ltd.) suspended in water containing a binder (SURFBEST 1100, product of NIPPON PAINT Co., Ltd.) was prepared. A Z-shaped flat tube made of aluminum extruded profile, a corrugated fin made of aluminum brazing sheet with layers of brazing material on both sides, aluminum side plates and two kinds of aluminum headers were prepared.

Various amounts (calculated from the flux itself) of the flux suspension were applied by brushing to the entire outer surface of the zigzag flat tube. Then, corrugated fins are arranged between each pair of adjacent straight pipe parts of each zigzag pipe, two corrugated fins are arranged outside each straight pipe part at both ends of the pipe, and two side plates are arranged on the The exterior of the corrugated fins at each end, the two headers are connected to the ends of the zigzag tube and the resulting assembly is secured with suitable clamps.

Subsequently, each fixed assembly was heated at a predetermined temperature in a heating furnace having a nitrogen atmosphere to braze the straight pipe portion and the side plate of the zigzag pipe to the corrugated fins, and braze the zigzag flat pipe to the corrugated fins. above the two headers to make the evaporator.

comparison example

A flux suspension comprising flux (FL-7, product of MoritaKagaku Co., Ltd.) suspended in water was prepared. A Z-shaped flat tube made of aluminum extruded profile, a corrugated fin made of aluminum brazing sheet with layers of brazing material on both sides, aluminum side plates and two aluminum headers were prepared.

Then, the corrugated fins are arranged between each pair of adjacent straight pipe parts of the zigzag pipe, the remaining corrugated fins are arranged outside each straight pipe part at both ends of the pipe, and the side plates are arranged on each end corrugated Shaped fins, two headers are attached to the ends of the zigzag tube, and the resulting assembly is secured with suitable clamps. Then, the flux suspension is sprayed onto the mounted components.

Subsequently, the fixed assembly is heated at a predetermined temperature in a heating furnace with a nitrogen atmosphere to braze the straight tube portion and the side plate of the zigzag tube to the corrugated fins, and braze the zigzag flat tube to the on the two headers, thus making the evaporator.

Evaluation experiment

The amount of flux remaining on the surface of the portion of the corrugated fin not brazed to the zigzag flat tube in each evaporator of Examples 1 to 4 and Comparative Example was checked. The results are shown in Table 1.

The amount of remaining flux was measured using the method described below. Degrease the JIS A1000 aluminum sample, apply a solution of polyvinyl alcohol in KCl to the sample, and then dry the sample at 170°C for 3 minutes, after which K is determined with an X-ray fluorescence meter (diameter 30 mm) K _alpha rays. This procedure was repeated by coating the specimen with different amounts of KCl to determine the correlation between the intensity of X-rays and the amount of K. Then, from this correlation, the correlation between the intensity of X-rays and KAlF ₄ is determined. Fluorescent X-rays were projected onto the surface of the portion of the corrugated fin not brazed to the zigzag flat tube in each of the evaporators of Examples 1 to 4 and Comparative Example to measure the intensity of the rays. According to the correlation between the intensity of X-ray and KAlF ₄ , the amount of remaining flux was determined by the intensity of X-ray.

In addition, the odor intensity of the evaporators of Examples 1-4 and Comparative Example was checked under an environment of a relative humidity of 90% and a temperature of 20°C.

Odor intensity is measured by the following method. The evaporators were inspected for odor by at least five panels qualified to determine odors and rated on a scale of 1-5. The stronger the smell, the higher the numerical value of the rating. The intensity of the odor was taken as the average of the ratings given by all panels.

Table 1 shows the inspection results and the amount of flux applied.

Table 1 Amount of flux applied (g/m ² ) Amount of flux residue (g/m ² ) odor intensity Example 1 0.08 0.06 1.7 Example 2 0.17 0.03 1.8 Example 3 1.48 0.11 1.7 Example 4 2.62 0.20 1.5 comparison example 4.00 3.80 2.2

The results given in Table 1 show that the evaporators of Examples 1-4 had a small amount of flux residue and a low intensity of odor compared to the evaporators of Comparative Examples. Furthermore, the results of Examples 1-4 show that the method of the present invention enables an uncorrelation between the amount of flux applied and the amount of flux residue.

Industrial Applicability

The evaporator of the present invention is suitable for use in motor vehicle air-conditioning equipment in which a chlorofluorocarbon refrigerant is used or a CO ₂ refrigerant is used.

Claims (18)

1. one kind comprises the hollow body of cold-producing medium circulation and the evaporimeter that passes through the fin of solder flux method for brazing soldering on this hollow body outer surface, and the amount of not soldering flux residue on the surface of the part on the hollow body of fin is 0.03-1g/m ²

2. evaporimeter according to claim 1 is characterized in that, the amount of not soldering residual solder flux on the surface of the part on the hollow body of fin is 0.05-0.5g/m ²

3. evaporimeter according to claim 1 is characterized in that, described solder flux is non-corrosive fluoride flux.

4. evaporimeter according to claim 1, it is characterized in that, the hollow body of described cold-producing medium circulation comprises the flat tube that bends to zigzag, described fin comprises by its both sides having the corrugated fin that the brazing sheet of brazing material layer is made, this corrugated fin be arranged between every pair of adjacent straight sections of zigzag flat tube and soldering thereon.

5. evaporimeter according to claim 1, it is characterized in that, described evaporimeter comprises a plurality of straight flat tubes that all constitute the hollow body of cold-producing medium circulation, described fin comprises by its both sides having the corrugated fin that the brazing sheet of brazing material layer is made, described a plurality of flat tube be arranged in parallel with being spaced apart from each other, described corrugated fin be arranged between every pair of adjacent flat pipe and soldering thereon.

6. evaporimeter according to claim 1, it is characterized in that, described evaporimeter comprises a plurality of hollow bodies that include the cold-producing medium circulation of two plates, the brazing sheet that described plate has a brazing material layer by its both sides is made and in the mutual soldering of its peripheral edge portion together, the collector formation portion of the protrusion that defines the coolant channel of protrusion between these two plates and be communicated with each end in the two ends of this coolant channel, described fin comprises corrugated fin, described a plurality of hollow body is stacked into and makes the outer surface of the collector formation portion on every pair of adjacent hollow body be in contact with one another, this corrugated fin be arranged between the corresponding part of coolant channel every pair of adjacent hollow body and corresponding and soldering on described hollow body.

7. evaporimeter according to claim 1 is characterized in that, described evaporimeter is through handling so that possess hydrophilic property.

8. one kind comprises compressor, condenser and evaporimeter and kind of refrigeration cycle that wherein use the chlorofluorocarbon cold-producing medium, and this evaporimeter is according to each described evaporimeter in the claim 1 to 7.

9. one kind is equipped with kind of refrigeration cycle according to claim 8 with the vehicle as motor vehicle air conditioning equipment.

10. method that is used to make evaporimeter, this method comprises: prepare to bend to zigzag and have the flat tube of refrigerant circulation passage in it and have the fin that the brazing sheet of brazing material layer is made by its both sides, use its amount and be 0.05-2.8g/m on the outer surface of this zigzag flat tube ²Solder flux, fin is arranged between every pair of adjacent straight sections of zigzag flat tube, and with fin brazed on the zigzag flat tube.

11. the method that is used to make evaporimeter according to claim 10 is characterized in that, the amount that is administered to the solder flux on the flat tube is 1-2g/m ²

12. method that is used to make evaporimeter, this method comprises: prepare a plurality of straight flat tubes that all have refrigerant circulation passage within it and have the fin that the brazing sheet of brazing material layer is made by its both sides, use its amount and be 0.05-2.8g/m on the outer surface of each flat tube ²Solder flux, described a plurality of flat tubes are be arranged in parallel with being spaced apart from each other, fin is arranged between every pair of adjacent flat pipe, and with fin brazed on flat tube.

13. the method that is used to make evaporimeter according to claim 12 is characterized in that, the amount that is administered to the solder flux on the flat tube is 1-2g/m ²

14. method that is used to make evaporimeter, this method comprises: prepare to have plate and the fin that the brazing sheet of brazing material layer is made by its both sides, described plate all has passage and forms protuberance and collector formation protuberance, and this collector forms the degree of protuberance protrusion and extends greater than this passage formation portion and each end from the two ends of this passage formation portion; To two surface applied solder flux of each plate, the amount that is applied in the solder flux on two kinds of protuberance outer surfaces of each plate is adjusted into 0.05-2.8g/m ²It is right that plate is arranged to pile up, each piles up all comprising the combination of two plates, wherein the opening of every kind of protuberance is opposite each other so that adjacent plate is in contact with one another the outer surface that last collector forms the diapire of protuberance with corresponding relation, fin is arranged on each passage adjacent plate and plate is formed between the corresponding part of protuberance; With two plates of every centering along the mutual soldering of peripheral edge portion together forming the hollow body of cold-producing medium circulation, and with fin brazed corresponding adjacent hollow body on.

15. the method that is used to make evaporimeter according to claim 14 is characterized in that, the amount that is administered to the solder flux on two kinds of protuberance outer surfaces of each plate is 1-2g/m ²

16. according to each described method that is used to make evaporimeter in the claim 10 to 15, it is characterized in that, solder flux be suspended in the water that contains adhesive use.

17. according to each described method that is used to make evaporimeter in the claim 10 to 15, it is characterized in that, corrugated fin be used as described fin.

18. according to each described method that is used to make evaporimeter in the claim 10 to 15, it is characterized in that, the assembly of soldering handled so that this assembly possess hydrophilic property at last.

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