JP6752377B2 - Compressor, refrigeration cycle device, and method of manufacturing compressor - Google Patents

Description

The present invention relates to a compressor, a refrigeration cycle device equipped with the compressor, and a method for manufacturing the compressor.

In a conventional compressor, in performing surface coating, a pretreatment for forming a zinc phosphate film or an iron phosphate film by chemical conversion treatment is performed for the purpose of improving coating film adhesion and corrosion resistance. After that, the surface of the outer peripheral wall of the compressor is coated by solvent coating or electrodeposition coating with a melamine coating film or the like for the purpose of protecting the material such as weather resistance or corrosion resistance and improving the design.

Generally, as a pretreatment for painting, it is said that the zinc phosphate coating treatment has better adhesion of the paint and corrosion resistance after painting than the iron phosphate coating treatment, and is the mainstream. However, the zinc phosphate treatment liquid is a treatment that is discarded because it is possible to control the film formation speed and the film morphology by adding heavy metal components such as zinc salt, nickel salt, and manganese salt to the zinc phosphate as the main component. Liquid phosphorus and heavy metals will be a burden to the environment. Further, since the zinc phosphate treatment is essentially a process of forming a film by etching an iron material, the eluted iron precipitates in the treatment liquid to generate sludge containing iron phosphate as a main component. Currently, in Japan, a large amount of sludge reaching about 5,000 tons / year is generated from zinc phosphate treatment and is disposed of as industrial waste. As described above, the zinc phosphate treatment is a process having a high environmental load in terms of both the components of the treatment liquid and the generation of sludge.

Further, since an organic solvent is used in the solvent coating or electrodeposition coating coating line, the environmental load is further increased from the viewpoint of emission regulation (VOC regulation) of volatile organic compounds. Therefore, a water-based inorganic zinc rich coating material as an anticorrosion base that embodies the reduction of volatile organic compounds (VOC) has been proposed (see, for example, Patent Document 1). Further, a powder coating material containing zinc powder, which is superior in rust prevention property of steel material to zinc rich coating material and does not emit volatile organic compounds (VOC), has been proposed (see, for example, Patent Document 2). Further, a compressor formed by powder coating in which emission of volatile organic compounds (VOCs) is suppressed has been proposed (see, for example, Patent Document 3).

JP-A-2009-249490 Japanese Unexamined Patent Publication No. 2004-99808 Japanese Unexamined Patent Publication No. 2017-25837

When a water-based inorganic zinc rich paint as shown in Patent Document 1 is used, a mist coat is required at the time of recoating the coating film because there are voids in the coating film in the coating process, and the humidity in the environment is reduced when the coating film is cured. There are restrictions such as the need to control. Since water-based inorganic zinc rich paint is expensive due to restrictions on the painting process, there are still problems as a painting method for mass production of compressors.

Further, when the compressor is powder coated by the electrostatic spraying method as shown in Patent Document 3, the powder coatings cause electrostatic repulsion to be formed on the bottom surface and the legs of the closed container. The powder coating material may not sufficiently enter the gap portion peculiar to the compressor, and the corrosion resistance of the portion may not be sufficiently guaranteed. In particular, when a powder coating material containing zinc powder as shown in Patent Document 2 is used, the greater the content of zinc powder per unit area, the more difficult it is for the powder coating material to fly due to the weight of the zinc powder. Therefore, when a powder coating material containing zinc powder is used, it becomes more difficult to apply the gap portion peculiar to the compressor formed between the bottom surface portion and the leg portion of the closed container, and the other portion is also applied. Wearing efficiency may decrease and workability may deteriorate. In the refrigeration cycle device, rainwater or condensed water collects in the outdoor unit to which the compressor is installed, so the bottom and legs of the airtight container of the compressor tend to be highly moist and corrode compared to other places. It may be easy. Therefore, it is indispensable to surely paint the portion in order to surely protect the compressor from corrosion.

The present invention has been made to solve the above problems, and is a compressor formed by a simplified process with a low environmental load, and a compressor provided with the coating film having corrosion resistance. It provides a refrigeration cycle apparatus equipped with a compressor, and a method for manufacturing the compressor.

The compressor according to the present invention has a closed container for accommodating an electric element and a compression element inside, a leg for fixing the closed container provided on the bottom surface of the closed container, and a surface of the closed container and the leg. A coating film formed by powder coating containing zinc powder, and the coating film includes a first coating layer in which the bottom surface and legs of the closed container are formed by a triboelectric charging method or a fluidized immersion method. and a second coating layer which is formed by a corona charging method, the upper side and a sealed container of the sealed container, have a second coating layer which is formed by a corona charging method, zinc dust in the first coating layer The content of zinc powder in the second coating layer is higher than the content of zinc powder .

In the compressor according to the present invention, the coating film is formed by a corona charging method with high coating efficiency in parts that are relatively easy to paint in the closed container, such as the side portion of the closed container and the upper part of the closed container. On the other hand, the coating film forms a gap portion peculiar to the compressor and is prone to corrosion, and the bottom surface and legs of the closed container, which are relatively difficult to paint, have a triboelectric charging method or flow with good penetration into the recess. It is formed using the dipping method. Therefore, the compressor has a coating film that is surely coated even in the gap portion peculiar to the compressor while aiming at the coating efficiency of the entire compressor. As a result, the compressor has a coating film formed by a simple and low environmental load coating process, and has corrosion resistance in parts that are prone to corrosion due to the formation of gaps such as the bottom surface and legs of the closed container. Can be improved.

It is a schematic schematic diagram which shows the refrigeration cycle apparatus provided with the compressor which concerns on Embodiment 1 of this invention. It is a vertical sectional view of the compressor which concerns on Embodiment 1 of this invention. It is a flow chart of the coating process of the compressor which concerns on Embodiment 1 of this invention. FIG. 5 is an enlarged schematic cross-sectional view of a bottom surface portion and a leg portion of a closed container in the compressor according to the first embodiment of the present invention. FIG. 5 is an enlarged schematic cross-sectional view of a side portion and an upper portion of a closed container in the compressor according to the first embodiment of the present invention. It is another cross-sectional enlarged schematic view of the bottom surface portion and the leg portion of the closed container in the compressor according to the first embodiment of the present invention. It is a vertical sectional view of the compressor which concerns on Embodiment 2 of this invention. It is a flow chart of the coating process of the compressor which concerns on Embodiment 2 of this invention. FIG. 5 is an enlarged schematic cross-sectional view of a bottom surface portion and a leg portion of a closed container in the compressor according to the second embodiment of the present invention. It is sectional drawing of the side part and the upper part of the closed container in the compressor which concerns on Embodiment 2 of this invention. It is another cross-sectional enlarged schematic view of the bottom surface portion and the leg portion of the closed container in the compressor according to the second embodiment of the present invention.

Hereinafter, the compressor and the refrigeration cycle apparatus according to the embodiment of the present invention will be described with reference to the drawings and the like. In the following drawings including FIG. 1, the relative dimensional relationships and shapes of the constituent members may differ from the actual ones. Further, in the following drawings, those having the same reference numerals are the same or equivalent thereof, and this shall be common to the entire text of the specification. In addition, terms that indicate directions (for example, "top", "bottom", "right", "left", "front", "rear", etc.) are used as appropriate for ease of understanding. For convenience of explanation, it is described as such, and does not limit the arrangement and orientation of the device or component.

Embodiment 1.
[Refrigeration cycle device 1]
FIG. 1 is a schematic schematic view showing a refrigeration cycle apparatus 1 provided with a compressor 2 according to a first embodiment of the present invention. The refrigeration cycle device 1 includes a compressor 2, a condenser 3 connected to the compressor 2, an expander 4 connected to the condenser 3, and an evaporator connected between the expander 4 and the compressor 2. 5 and. As shown in FIG. 1, the refrigerating cycle device 1 constitutes a refrigerant circulation circuit by connecting a compressor 2, a condenser 3, an expansion device 4, and an evaporator 5 in series with a refrigerant pipe. The compressor 2 is, for example, a rotary type compressor, which compresses the low-pressure vapor-phase refrigerant taken into the compressor and changes it into a high-temperature and high-pressure vapor-phase refrigerant. The condenser 3 dissipates heat from the high-temperature and high-pressure gas-phase refrigerant sent from the compressor 2, and changes the vapor-phase refrigerant into a high-pressure liquid-phase refrigerant. The expansion device 4 lowers the pressure of the high-pressure liquid-phase refrigerant sent from the condenser 3 and changes it into a low-temperature low-pressure liquid-phase refrigerant. The evaporator 5 vaporizes the liquid phase refrigerant sent from the expansion device 4 and changes it into a low pressure gas phase refrigerant. At this time, the heat of vaporization is taken away by the phase-changing refrigerant, and the periphery of the evaporator 5 is cooled. The vapor phase refrigerant that has taken away the heat of vaporization is taken into the compressor 2 again. As described above, in the refrigeration cycle device 1, the refrigerant as the working fluid circulates while changing the phase between the gas phase refrigerant and the liquid phase refrigerant. Heat is dissipated from the refrigerant in the process of phase change from the gas phase refrigerant to the liquid phase refrigerant, and heat is absorbed by the refrigerant in the process of phase change from the liquid phase refrigerant to the vapor phase refrigerant. Heating and cooling are performed using these heat dissipation and heat absorption.

[Compressor 2]
FIG. 2 is a vertical sectional view of the compressor 2 according to the first embodiment of the present invention. The compressor 2 is a closed type including a closed container 6 for accommodating the electric element 7 and the compression element 8 inside, and a leg portion 14 for fixing the closed container 6 to the bottom surface portion 6c of the closed container 6. It is an electric compressor. Further, the compressor 2 has a coating film 20 formed by powder coating containing zinc powder on the surfaces of the closed container 6 and the leg portion 14.

The closed container 6 is composed of a bottom closed cylindrical container 6a and an upper closed container 6b that closes the upper opening of the lower closed container 6a. In the closed container 6, the connecting portion between the lower closed container 6a and the upper closed container 6b is fixed by welding, and the closed state is maintained.

A suction pipe 9 is connected to the lower closed container 6a, and a gas-liquid separator 10 is attached to the suction pipe 9. The suction pipe 9 is a connecting pipe for sending the gas refrigerant flowing in through the gas-liquid separator 10 into the compression element 8. An upper suction pipe 11 is provided above the gas-liquid separator 10, and the upper suction pipe 11 is connected to the evaporator 5 of the refrigeration cycle to guide the refrigerant into the gas-liquid separator 10. Refrigerating machine oil 12 supplied to the compression element 8 via the inside of the crankshaft 13 is stored on the inner wall side of the bottom surface portion 6c of the lower closed container 6a. Further, a leg portion 14 is provided on the outer wall side of the bottom surface portion 6c of the closed container 6. The legs 14 are for fixing the closed container 6 to the outdoor unit of the refrigeration cycle device 1.

A discharge pipe 15 is connected to the upper closed container 6b on a shaft extension line of the crankshaft 13. The discharge pipe 15 is connected to the condenser 3 of the refrigeration cycle, and sends out the high-pressure refrigerant compressed by the compression element 8 to the refrigeration cycle. The discharge pipe 15 may be provided in the closed container 6 and may not necessarily be provided on the extension line of the crankshaft 13.

The electric element 7 is arranged at the upper part in the closed container 6. The electric element 7 includes a stator 16 fixed to the lower airtight container 6a, and a rotor 17 rotatably provided on the inner peripheral side of the stator 16. A crankshaft 13 is fixed to the center of the rotor 17. The stator 16 is fixed to the lower closed container 6a of the closed container 6 by various fixing methods such as shrink fitting and welding.

The compression element 8 is housed in the closed container 6 and compresses the refrigerant flowing into the closed container 6. The compression element 8 is a rotary compression mechanism having a cylindrical cylinder. The compression element 8 is arranged below the electric element 7 in the closed container 6 and is fixed to the lower closed container 6a. The compression element 8 fits into the crankshaft 13 driven by the rotor 17 of the electric element 7, the cylinder 18 concentric with the crankshaft 13, and the eccentric shaft of the crankshaft 13, and rolls eccentrically in the cylinder 18. It has a piston 19. Further, the compression element 8 has a cylinder head 22 that closes the lower end surface of the cylinder 18, and a frame 21 that closes the upper end face of the cylinder 18.

[Coating film 20]
The closed container 6 and the legs 14 are made of steel, and the outer peripheral wall surface is coated with a coating film 20 coated with a powder coating material containing zinc powder. The coating film 20 has a first coating layer 20a formed by a triboelectric charging method or a fluidized immersion method and a second coating layer 20b formed by a corona charging method on the bottom surface portion 6c and the leg portion 14 of the closed container 6. .. Further, the coating film 20 has a second coating layer 20b formed by a corona charging method on the side portion 6d of the closed container 6 and the upper portion 6e of the closed container 6. The coating film thickness of the coating film 20 is 70 to 300 μm. The lower the zinc powder content per unit area in the powder coating material containing zinc powder, the higher the coating efficiency, but the lower the sacrificial anticorrosion effect of zinc, which has a higher ionization tendency than iron, and thus the anticorrosion property. Goes down. Therefore, as a result of considering these balances, the zinc powder content of the coating film 20 is preferably 20 to 60 wt%.

The film thickness of the coating film 20 can be confirmed by using a film thickness meter or by observing the cross sections of the closed container 6 and the leg portion 14 with a microscope. The zinc content in the coating film 20 can be confirmed by SEM / EDX analysis of the surface of the coating film 20. The adhesion of the coating film 20 can be evaluated by a test method (width 2 mm, 100 squares, tape peeling) based on JIS K5600-5-6. The adhesion of the coating film 20 of the compressor 2 shows good adhesion without peeling even one mass, and has sufficient coating film adhesion without performing coating pretreatment such as zinc phosphate film formation. It was confirmed.

[Painting process of coating film 20]
FIG. 3 is a flow chart of a coating process of the compressor 2 according to the first embodiment of the present invention. FIG. 4 is an enlarged schematic cross-sectional view of the bottom surface portion 6c and the leg portion 14 of the closed container 6 in the compressor 2 according to the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional enlarged view of the side portion 6d and the upper portion 4e of the closed container 6 in the compressor 2 according to the first embodiment of the present invention. 3 to 5 show a coating process for forming the coating film 20 in the method for manufacturing the compressor 2. First, a compressor 2 in an unpainted state is prepared. Since rust preventive oil or processing oil that hinders the adhesion of the coating film adheres to the surface of the compressor 2, the surfaces of the closed container 6 and the leg 14 are cleaned for the purpose of degreasing as a cleaning step ( Step S11). Examples of the cleaning method include alkaline cleaning using sodium hydroxide and cleaning with a surfactant. In the case of the coating process according to the prior art, after the cleaning process, a zinc phosphate film is formed by a chemical conversion treatment for the purpose of improving the adhesion and corrosion resistance of the coating. However, in the coating process of the coating film 20, the coating process of the zinc phosphate coating film can be omitted because the coating material has high corrosion resistance.

Next, the washed compressor 2 is grounded, and a powder coating material containing zinc powder and charged is sprayed onto the compressor 2. At this time, as the first coating step, in order to reliably paint in the gap between the bottom surface portion 6c of the closed container 6 and the leg portion 14, the bottom surface portion 6c of the closed container 6 is subjected to a triboelectric charging method having good penetration into the recess. And the leg portion 14, the powder coating is sprayed (step S12). As a result, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have the first coating layer 20a formed by the triboelectric charging method as shown in FIG. The coating conditions of the first coating process by the triboelectric charging method are, for example, a conveyor speed of 0.3 to 1.0 m / min, a discharge rate of 50 to 300 g / min, and a distance between the spray and the compressor 2 of 50 to 300 mm. The air pressure is 0.1 to 0.3 MPa. The coating conditions are not limited to the above coating conditions because it is assumed that the optimum values differ depending on the size and shape of the equipment or the compressor 2. Further, the coating on the bottom surface portion 6c and the leg portion 14 of the closed container 6 is limited to the triboelectric charging method as long as the gap portion between the bottom surface portion 6c and the leg portion 14 of the closed container 6 is surely painted. It is also possible to attach the powder coating by, for example, a fluidized dipping method. In this case, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have a first coating layer 20a formed by the flow dipping method.

Next, as the second coating step, the powder coating is sprayed on the entire compressor 2, that is, the closed container 6 and the legs 14 by the corona charging method having high coating efficiency (step S13). As a result, the side portion 6d of the closed container 6 and the upper portion 6e of the closed container 6 have a second coating layer 20b formed by the corona charging method as shown in FIG. Further, as shown in FIG. 4, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have a second coating layer 20b formed by the corona charging method. The coating conditions for the second coating process by the corona charging method are a conveyor speed of 0.3 to 1.0 m / min, a discharge rate of 50 to 300 g / min, a distance between the spray and the compressor 2 of 100 to 300 mm, and air pressure. Is carried out at 0.1 to 0.3 MPa. The coating conditions of the second coating step by the corona charging method are such that the applied voltage is -10 to -100 kV and the output current is 5 to 80 μA. As a result, the coating film 20 is formed by a charging method different from the charging method in which the bottom surface portion 6c and the leg portion 14 of the closed container 6 form the coating film on the side portion 6d and the upper portion 6e of the closed container 6. Has. The coating conditions are not limited to the above coating conditions because it is assumed that the optimum values differ depending on the size and shape of the equipment or the compressor 2.

Normally, the flow path of the paint of the triboelectric charging method is made of Teflon (registered trademark), and the paint passing through the flow path is positively charged. When a powder coating gun made by Teflon (registered trademark) is used and then powder coating is sprayed by the corona charging method, the coating speed becomes uneven due to the difference in the charge of the coating, and wavy patterns appear on the coating surface. May appear. The wavy pattern that appears on the painted surface becomes inconspicuous during the baking process. Since the compressor 2 is arranged inside the outdoor unit and cannot be seen from the outside, high designability is generally not required. However, if you want to eliminate this pattern, the paint gun used for the triboelectric charging method may be made of glass or ceramic, and the paint may be negatively charged to suppress uneven coating speed. The design of the can be improved.

FIG. 6 is another cross-sectional enlarged schematic view of the bottom surface portion 6c and the leg portion 14 of the closed container 6 in the compressor 2 according to the first embodiment of the present invention. The order of painting the bottom surface portion 6c and the leg portion 14 of the closed container 6 and painting the entire compressor 2 may be reversed. That is, as the first coating step, the powder coating is sprayed on the entire compressor 2, that is, the closed container 6 and the legs 14 by the corona charging method having high coating efficiency (step S12). Next, as a second painting step, in order to reliably paint in the gap between the bottom surface 6c of the closed container 6 and the leg 14, the bottom surface 6c of the closed container 6 is subjected to a triboelectric charging method having good penetration into the recess. And the leg portion 14, the powder coating is sprayed (step S13). In this way, the powder coating is first sprayed on the entire compressor 2 by the corona charging method, and then the powder coating is sprayed on the bottom surface 6c and the legs 14 of the closed container 6 by the triboelectric charging method. You may. In this case, as shown in FIG. 6, the coating film 20 is subjected to the second coating layer 20b formed by the corona charging method, the triboelectric charging method or the fluidized immersion method from the bottom surface portion 6c and the leg portion 14 side of the closed container 6. It is configured in the order of the formed first coating layer 20a. The coating film 20 on the bottom surface portion 6c and the leg portion 14 of the closed container 6 has two layers, a first coating layer 20a and a second coating layer 20b, which have different zinc powder contents per unit area. The coating film 20 on the bottom surface 6c and the leg 14 of the closed container 6 is limited to those having two layers, a first coating layer 20a and a second coating layer 20b, which have different zinc powder contents per unit area. It is not something that is done. Even if the coating film 20 on the bottom surface portion 6c and the leg portion 14 of the closed container 6 has two layers of the first coating layer 20a and the second coating layer 20b having the same zinc powder content per unit area. Good.

Finally, as a heating step, the closed container 6 and the legs 14 sprayed with the powder paint are heated in a baking drying furnace, and the coating film 20 is formed on the outer peripheral surfaces of the closed container 6 and the legs 14 by thermosetting (thermosetting). Step S14).

As described above, the coating film 20 of the compressor 2 is a corona charging method having good coating efficiency in the parts that are relatively easy to paint in the closed container 6, such as the side portion 6d of the closed container 6 and the upper portion 6e of the closed container 6. Is formed by. On the other hand, the coating film 20 of the compressor 2 forms a gap portion peculiar to the compressor 2, and corrosion is likely to occur, and the bottom surface portion 6c and the leg portion 14 of the closed container 6 which are relatively difficult to paint have recesses. It is formed by using a triboelectric charging method or a fluid immersion method having good penetrability. Therefore, the compressor 2 has a coating film 20 that is surely coated even in the gap portion peculiar to the compressor 2 while aiming at the coating efficiency of the entire compressor 2. As a result, the compressor 2 has a coating film 20 formed by a simple and low environmental load coating process, and has gaps such as the bottom surface 6c and the legs 14 of the closed container 6, so that corrosion is likely to occur. The corrosion resistance of the part can be improved.

Further, since the compressor 2 is coated by powder coating containing zinc powder and has a coating film formed by powder coating containing zinc powder, zinc in the coating serves as a sacrificial anticorrosive layer. Has a high corrosion resistance effect. Therefore, the compressor 2 can omit the coating pretreatment (zinc phosphate treatment and iron phosphate treatment) step, and adopts powder coating as a coating method that does not use an organic solvent, so that the coating step The emission of volatile organic compounds (VOC) can be suppressed. In addition, since powder coating can recycle paint, it is possible to reuse paint lost in the painting process, and it is possible to realize a painting process with a very low environmental load compared to conventional technology. Become. As a result, the compressor 2 is manufactured by a simple coating process having a low environmental load.

Further, in the compressor 2, the coating film 20 of the bottom surface portion 6c and the leg portion 14 of the closed container 6 has two layers, a first coating layer 20a and a second coating layer 20b, in which the zinc powder content per unit area is different. Has. Therefore, the compressor 2 has a coating film 20 that is surely coated even in the gap portion peculiar to the compressor 2 while aiming at the coating efficiency of the entire compressor 2. As a result, the compressor 2 has a coating film 20 formed by a simple and low environmental load coating process, and has gaps such as the bottom surface 6c and the legs 14 of the closed container 6, so that corrosion is likely to occur. The corrosion resistance of the part can be improved.

Further, in the coating film 20 of the compressor 2, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have a first coating layer 20a containing zinc powder and a second coating layer 20b containing zinc powder. The side portion 6d of the closed container 6 and the upper portion 6e of the closed container have a second coating layer 20b containing zinc powder. Therefore, the compressor 2 can reliably coat the gap portion peculiar to the compressor 2 while aiming at the coating efficiency of the entire compressor 2 in the coating process. As a result, the compressor 2 can carry out a simple and environmentally friendly coating process, and has corrosion resistance of parts such as the bottom surface 6c and the legs 14 of the closed container 6 that are prone to corrosion due to the gaps. Can be improved.

Further, in solvent coating and electrodeposition coating, the film thickness is usually about 20 to 40 μm, and it is difficult to thicken the film. On the other hand, in powder coating, it has been confirmed that the film thickness retention is as thick as 80 to 300 μm, and it is possible to improve the corrosion resistance from the viewpoint of film thickness. Further, since the bottom surface 6c of the closed container 6 and the vicinity of the leg 14 are painted twice, the film thickness becomes thicker toward the bottom surface 6c and the leg 14 of the closed container 6, and the portion where corrosion is likely to occur. Corrosion resistance is improved.

Further, since the refrigeration cycle device 1 includes the compressor 2 according to the first embodiment, it is possible to realize a coating process having a very low environmental load as compared with the conventional technique.

Embodiment 2.
FIG. 7 is a vertical sectional view of the compressor 2 according to the second embodiment of the present invention. FIG. 8 is a flow chart of a coating process of the compressor 2 according to the second embodiment of the present invention. Parts having the same configuration as the compressor 2 of FIGS. 1 to 7 are designated by the same reference numerals. The explanation is omitted. The compressor 2 according to the second embodiment has a coating film 20 in the vicinity of the bottom surface portion 6c and the leg 19 portion of the closed container 6 in which corrosion is likely to occur, per unit area as compared with the coating film 20 by the paint in the step of painting the whole. It has a coating film 120 having a high zinc powder content. The closed container 6 and the legs 14 are made of steel, and the outer peripheral wall surface is coated with a coating film 120 coated with a powder coating material containing zinc powder. The coating film 120 has a first coating layer 120a formed by a triboelectric charging method or a fluidized immersion method and a second coating layer 120b formed by a corona charging method on the bottom surface portion 6c and the leg portion 14 of the closed container 6. .. Further, the coating film 120 has a second coating layer 120b formed by a corona charging method on the side portion 6d of the closed container 6 and the upper portion 6e of the closed container 6.

[Painting process of coating film 120]
FIG. 9 is a schematic cross-sectional enlarged view of the bottom surface portion 6c and the leg portion 14 of the closed container 6 in the compressor 2 according to the second embodiment of the present invention. FIG. 10 is an enlarged sectional view of a side portion 6d and an upper portion 4e of the closed container 6 in the compressor 2 according to the second embodiment of the present invention. 8 to 10 show a coating process for forming the coating film 120 in the method for manufacturing the compressor 2. First, a compressor 2 in an unpainted state is prepared. Since rust preventive oil or processing oil that hinders the adhesion of the coating film adheres to the surface of the compressor 2, the surfaces of the closed container 6 and the leg 14 are cleaned for the purpose of degreasing (step S21). Examples of the cleaning method include alkaline cleaning using sodium hydroxide and cleaning with a surfactant. In the case of the coating process according to the prior art, after the cleaning process, a zinc phosphate film is formed by a chemical conversion treatment for the purpose of improving the adhesion and corrosion resistance of the coating. However, in the coating process of the coating film 120, the coating process of the zinc phosphate coating film can be omitted because the coating material has high corrosion resistance.

Next, the washed compressor 2 is grounded, and a powder coating material containing zinc powder and charged is sprayed onto the compressor 2. At this time, as the first coating, in order to reliably paint in the gap between the bottom surface portion 6c of the closed container 6 and the leg portion 14, the bottom surface portion 6c of the closed container 6 is subjected to a triboelectric charging method having good penetration into the recess. A powder coating material containing 60 to 90 wt% of zinc powder is sprayed onto the legs 14 (step S22). As a result, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have a first coating layer 120a formed by the triboelectric charging method as shown in FIG. The coating conditions for the first coating by the triboelectric charging method are, for example, a conveyor speed of 0.3 to 1.0 m / min, a discharge rate of 50 to 300 g / min, a distance between the spray and the compressor 2 of 50 to 300 mm, and air. The pressure is 0.1 to 0.3 MPa. The coating conditions are not limited to the above coating conditions because it is assumed that the optimum values differ depending on the size and shape of the equipment or the compressor 2. Further, the coating on the bottom surface portion 6c and the leg portion 14 of the closed container 6 is limited to the triboelectric charging method as long as the gap portion between the bottom surface portion 6c and the leg portion 14 of the closed container 6 is surely painted. It is also possible to attach the powder coating by, for example, a fluidized dipping method. In this case, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have a first coating layer 120a formed by the flow dipping method.

Next, as a second coating step, a powder coating material containing 20 to 60 wt% of zinc powder is sprayed onto the entire compressor 2, that is, the closed container 6 and the leg portion 14 by a corona charging method with good coating efficiency. (Step S23). At this time, the booths for painting by the triboelectric charging method and painting by the corona charging method are separated. As a result, the side portion 6d of the closed container 6 and the upper portion 6e of the closed container 6 have a second coating layer 120b formed by the corona charging method as shown in FIG. Further, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have a second coating layer 120b formed by the corona charging method, as shown in FIG. That is, by these spraying, the coating film 120 of the bottom surface portion 6c and the leg portion 14 of the closed container 6 has two layers having different zinc contents per unit area, that is, the first coating layer 120a and the second coating layer 120b. Have. In the second coating step, as the zinc powder content per unit area increases, the corrosion resistance improves, but the coating efficiency decreases and the price may increase. Therefore, in consideration of the balance between coating efficiency, price, and corrosion resistance, in the second coating process, which is the entire coating, the zinc powder content is 20 to 60 wt%. The coating conditions for the second coating process by the corona charging method are a conveyor speed of 0.3 to 1.0 m / min, a discharge rate of 50 to 300 g / min, a distance between the spray and the compressor 2 of 100 to 300 mm, and air pressure. Is carried out at 0.1 to 0.3 MPa. The coating conditions of the second coating step by the corona charging method are such that the applied voltage is -10 to -100 kV and the output current is 5 to 80 μA. As a result, the coating film 120 is formed by a charging method different from the charging method in which the bottom surface portion 6c and the leg portion 14 of the closed container 6 form the coating film on the side portion 6d and the upper portion 6e of the closed container 6. Has. The coating conditions are not limited to the above coating conditions because it is assumed that the optimum values differ depending on the size and shape of the equipment or the compressor 2. In the compressor 2, the unit area of the powder coating material used in the first coating process is larger than that of the powder coating material used in the first coating process in the comparison between the first coating process and the second coating process. The content of zinc powder per hit is high. Therefore, the content of zinc powder per unit area of the first coating layer 120a is higher than that of the second coating layer 120b. Therefore, in the coating film 120, the zinc powder content per unit area of the bottom surface portion 6c and the leg portion 14 of the closed container 6 is per unit area of other parts of the closed container 6, for example, the side portion 6d and the upper portion 6e. Higher than zinc powder content.

FIG. 11 is another cross-sectional enlarged schematic view of the bottom surface portion 6c and the leg portion 14 of the closed container 6 in the compressor 2 according to the second embodiment of the present invention. The order of painting the bottom surface 6c and the legs 14 of the closed container 6 and painting the entire compressor 2 may be reversed. That is, as the first coating, the powder coating is sprayed on the entire compressor 2, that is, the closed container 6 and the legs 14 by the corona charging method having high coating efficiency (step S22). Next, as a second painting step, in order to reliably paint in the gap between the bottom surface 6c of the closed container 6 and the leg 14, the bottom surface 6c of the closed container 6 is subjected to a triboelectric charging method having good penetration into the recess. And the leg portion 14, the powder coating is sprayed (step S23). In this way, the powder coating is first sprayed on the entire compressor 2 by the corona charging method, and then the powder coating is sprayed on the bottom surface 6c and the legs 14 of the closed container 6 by the triboelectric charging method. You may. In this case, as shown in FIG. 11, the coating film 120 is formed from the bottom surface portion 6c and the leg portion 14 side of the closed container 6 by the second coating layer 120b formed by the corona charging method, the triboelectric charging method or the flow immersion method. The first coating layer 120a is formed in this order.

Finally, as a heating step, the closed container 6 and the legs 14 sprayed with the powder coating are heated in a baking drying furnace, and the coating film 120 is formed on the outer peripheral surfaces of the closed container 6 and the legs 14 by thermosetting (thermosetting). Step S24).

As described above, the coating film 120 of the compressor 2 according to the second embodiment is coated on the portion of the closed container 6 that is relatively easy to be painted, such as the side portion 6d of the closed container 6 and the upper portion 6e of the closed container 6. It is formed by an efficient corona charging method. On the other hand, the coating film 120 of the compressor 2 forms a gap portion peculiar to the compressor 2, and corrosion is likely to occur, and the bottom surface portion 6c and the leg portion 14 of the closed container 6 which are relatively difficult to paint have recesses. It is formed by using a triboelectric charging method or a fluid immersion method having good penetrability. Therefore, the compressor 2 can reliably coat the gap portion peculiar to the compressor 2 while aiming at the coating efficiency of the entire compressor 2 in the coating process. As a result, the compressor 2 can carry out a simple and environmentally friendly coating process, and has corrosion resistance of parts such as the bottom surface 6c and the legs 14 of the closed container 6 that are prone to corrosion due to the gaps. Can be improved.

Further, since the compressor 2 is coated by powder coating containing zinc powder, zinc in the coating serves as a sacrificial anticorrosion layer and has a high corrosion resistance effect. Therefore, the compressor 2 can omit the coating pretreatment (zinc phosphate treatment and iron phosphate treatment) step, and adopts powder coating as a coating method that does not use an organic solvent, so that the coating step The emission of volatile organic compounds (VOC) can be suppressed. In addition, since powder coating can recycle paint, it is possible to reuse paint lost in the painting process, and it is possible to realize a painting process with a very low environmental load compared to conventional technology. Become. As a result, the compressor 2 is manufactured by a simple coating process having a low environmental load.

Further, in the coating film 120 of the compressor 2, the bottom surface portion 6c and the leg portion 14 of the closed container 6 have a first coating layer 120a containing zinc powder and a second coating layer 120b containing zinc powder. The side portion 6d of the closed container 6 and the upper portion 6e of the closed container have a second coating layer 120b containing zinc powder. Therefore, the compressor 2 can reliably coat the gap portion peculiar to the compressor 2 while aiming at the coating efficiency of the entire compressor 2 in the coating process. As a result, the compressor 2 can carry out a simple and environmentally friendly coating process, and has corrosion resistance of parts such as the bottom surface 6c and the legs 14 of the closed container 6 that are prone to corrosion due to the gaps. Can be improved.

Further, in the compressor 2 according to the second embodiment, zinc per unit area is surely formed on the bottom surface portion 6c and the leg portion 14 of the closed container 6 having a complicated shape as compared with the side portion 6d and the upper portion 6e of the closed container 6. A coating film 120 having a high content is formed. Therefore, the compressor 2 is installed near the bottom of the outdoor unit, and the corrosion resistance of the portion where corrosion is particularly likely to occur is improved.

Further, in the compressor 2, in the comparison between the first coating process and the second coating process, the powder coating material used in the first coating process is more in the coating film 120 than the powder coating material used in the first coating process. The content of zinc powder per unit area is high. Therefore, it is possible to more reliably protect the vicinity of the bottom surface portion 6c and the leg portion 14 of the compressor 2 from which corrosion is likely to occur due to the structure of the compressor 2.

Further, in the coating film 120 of the compressor 2, the zinc powder content per unit area of the first coating layer 120a is larger than the zinc powder content per unit area of the second coating layer 120b. Therefore, it is possible to more reliably protect the vicinity of the bottom surface portion 6c and the leg portion 14 of the compressor 2 from which corrosion is likely to occur due to the structure of the compressor 2.

Further, the compressor 2 has a coating film in which the zinc powder content per unit area of the bottom surface portion 6c and the leg portion 14 of the closed container 6 is larger than the zinc powder content per unit area of the other portion of the closed container 6. Has 120. As a result, the compressor 2 has a coating film 120 formed by a simple and low environmental load coating process, and has gaps such as the bottom surface 6c and the legs 14 of the closed container 6, so that corrosion is likely to occur. The corrosion resistance of the part can be improved.

Further, in the painting process, the compressor 2 has separate booths for the painting process in the vicinity of the bottom surface portion 6c and the leg portion 14 of the compressor 2 and the entire coating process thereafter, so that the paint can be applied to each booth. It can be collected and recycled, enabling an environmentally friendly painting process.

Further, since the refrigeration cycle apparatus 1 includes the compressor 2 according to the second embodiment, it is possible to realize a coating process having a very low environmental load as compared with the conventional technique.

1 Refrigeration cycle device, 2 Compressor, 3 Condenser, 4 Expansion device, 4e Upper part, 5 Evaporator, 6 Closed container, 6a Lower closed container, 6b Upper closed container, 6c Bottom part, 6d side part, 6e upper part, 7 Electric element, 8 compressor element, 9 suction pipe, 10 gas-liquid separator, 11 upper suction pipe, 12 refrigerating machine oil, 13 crankshaft, 14 legs, 15 discharge pipe, 16 stator, 17 rotor, 18 cylinder, 19 Rolling piston, 20 coatings, 20a first coating layer, 20b second coating layer, 21 frames, 22 cylinder heads, 120 coatings, 120a first coating layer, 120b second coating layer.

Claims (4)

A closed container for storing electric elements and compression elements inside,
Legs for fixing the closed container provided on the bottom surface of the closed container, and
A coating film formed by powder coating containing zinc powder on the surfaces of the closed container and the legs,
With
The coating film is
The bottom surface portion and the leg portion of the closed container have a first coating layer formed by a triboelectric charging method or a fluidized immersion method and a second coating layer formed by a corona charging method.
The top side and the closed container of the sealed container, have a second coating layer which is formed by a corona charging method,
A compressor in which the content of zinc powder in the first coating layer is higher than the content of zinc powder in the second coating layer . A closed container for storing electric elements and compression elements inside,
Legs for fixing the closed container provided on the bottom surface of the closed container, and
A coating film formed by powder coating containing zinc powder on the surfaces of the closed container and the legs,
With
The coating film is
The bottom surface portion and the leg portion of the closed container have a first coating layer containing zinc powder and a second coating layer containing zinc powder.
The top side and the closed container of the sealed container, have a second coating layer containing zinc dust,
A compressor in which the content of zinc powder in the first coating layer is higher than the content of zinc powder in the second coating layer . The compressor according to claim 1 or 2 , a condenser connected to the compressor, an expander connected to the condenser, and an evaporator connected between the expander and the compressor. And equipped with a refrigeration cycle device. A first coating step of spraying a powder paint containing zinc dust to the leg portion of the hermetic container and the bottom portion of the hermetic container by friction charging method or flow immersion method,
A second coating step of spraying a powder coating material containing zinc powder onto the entire closed container by the corona charging method, and
A heating step of heating the closed container to which the powder paint is sprayed and the leg portion in a baking drying furnace and forming a coating film on the outer peripheral surface of the closed container and the leg portion by thermosetting.
Have a,
A method for producing a compressor in which the powder coating material used in the first coating step has a higher content of zinc powder per unit area in the coating film than the powder coating material used in the second coating process .

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