KR850001413B1 - Manufacture of plastic silencer for sealed type compressor - Google Patents

Abstract

A manufacturing method for a plastic silencer for a sealedtype compressor has the following seps. (1) A flange thinner than the thickness of the silencer wall is formed on the margin of the silencer. (2) When a gap forms between the upper and lower margins of the silencer and flanges, the upper and lower parts of the silencer are adhered to each other. (3) The upper and lower flanges of the silencer are then pressed using pressurizing device. (4) The outside margin part of the flange is melted and adhered by directing hot air onto the outside end part projected from the outside margin of the silencer. (5) The silencer part is then melted onto the chief body part to connect them.

Description

Manufacturing method of plastic silencer of hermetic compressor

1 is a perspective view showing the structure of an electrically operated hermetic extruder.

2 is a perspective view of a plastic muffler made according to a manufacturing method according to one embodiment of the invention.

FIG. 3 is a cross-sectional view taken along the arrow III-III line in FIG. 2, showing a state in which silencer components are coupled to each other by hot air fusion.

4 is a cross-sectional view of a plastic silencer produced by hot air fusion as shown in FIG.

5A to 5C are cross-sectional views of the wall surface of the coolant passage and show a state in which silencer components are joined to each other to form a wall.

The present invention relates to a method for attaching a muffler for a hermetic extruder, and more particularly, in the plastic muffler used in a small refrigeration unit, the components of the muffler are made in advance and combined with each other to improve the efficiency of the plastic muffler. And a manufacturing method capable of improving performance.

Referring to FIG. 1, the schematic structure of a conventional hermetic electric extruder will be described. In the figure, the extruder has a crank exit 1, a piston 2, and an electric motor 3, a cylinder 4, and a cylinder head 5, a suction pipe 6, It consists of an intake side silencer 7, and an outlet side silencer 8.

The returned coolant, which has a relatively low temperature, enters the cylinder 4 quickly from the suction pipe 6 through the suction side silencer 7 and the cylinder head 5 and is discharged from the cylinder 4 through the discharge side silencer 8 and the cylinder head 5 in the extrusion process of the piston 2. In the hermetic electric extruder as described above, the suction side silencer 7 is made of a metal plate and a metal tube, so the thermal conductivity is large. Thus, the suction side silencer 7 is heated by the heat conducted from the high temperature cylinder head 5. In this case, since the refrigerant gas is heated, the specific volume of the refrigerant gas increases. This, in turn, reduces the practical work of the compressor, so the muffler 7 has the disadvantage of reducing the efficiency of the compressor.

To minimize this drawback, a conceivable solution is to make a heated silencer with a large thermal resistance material, such as a thermoplastic material, that can significantly block sound. You can think of However, the suction side silencer of a complicated structure in which the suction part, which is in the shape of a box, the expansion chamber and the resonance chamber are integrally formed while acting as the passage of the refrigerant is applied to the injection molding. Is making it very difficult to make. The reason for this is that it is impossible to make a mold in which the suction side silencer of a complicated structure is integrally formed.

This suction-side silencer can actually be made in advance by dividing it into several parts and combining these parts together. There are several methods of bonding plastic parts together. The methods are fusion by hot plates. This method involves contacting a preheated hot plate to the surface to be bonded to melt the surface, and then joining the parts together.

A method of fusing an adhesive portion by ultrasonic vibration energy. And a bonding method by thermosetting adhesive paper. This method is representative of epoxy resin as a thermosetting adhesive, and in order to achieve effective adhesion, the adhesive of the bonded portion must be heated. All of these methods have the drawback that the inside surface of the passage of the refrigerant is easily rubbed, silt of plastic, and debris of plastic. These defects increase the resistance of the flow as the refrigerant flows through the refrigerant pipe (path of the refrigerant) and cause a failure of the suction valve, or a piston or cylinder. Even if any one of these phenomena occurs, the compressor does not perform its function and the operation is stopped, thus the reliability is significantly reduced. In addition, the process of applying a heat curable adhesive and the process of heating the right adhesive have the disadvantage that the productivity is very slow.

Accordingly, an object of the present invention is to fuse the plastic parts with high efficiency in a short time, and to have high strength and airtightness without generating defects such as grime, plastic chips and plastic chips in the passage of the refrigerant. The present invention provides a method for producing a compressor silencer made of plastic with good dimensions and high precision. In order to achieve the above object, in the present invention, when the respective parts of the muffler are overlapped with each other, the outer edge of the muffler portion has a gap between the flange and the flange formed therein, and each inner edge of each other Tightly coupled.

Then, while applying pressure over the entire length of the flange while supplying hot air to the outer edge of the silencer parts and the flange to melt the flange parts to each other by using a method of manufacturing a plastic silencer of the hermetic compressor by fusion. When fusion is performed by this method, pressure is continuously applied on the inner edge wall of the refrigerant pipe (the passage of the refrigerant) formed by the inner edges of the silencer portions closely adhered to each other, so that the passage of the refrigerant is airtight and reliable. OFF The inner edge wall of the passage of the coolant makes good contact with each other. When the muffler parts are overlapped with each other, the gap between the outer edge of the muffler part and the flanges is increased, or the thickness of the wall of the muffler, which is formed of plastic, is thickened, and the flexural modulus is increased. The use of plastic material reinforced with large glass fibers will certainly increase the force exerted on the inner edges of the muffler sections. Plastic materials that can be satisfactory in this outbreak include polybutylene terephthalate resins, polyethylene terephthalate resins, polyacetar resins, polyamide resins, and the like. It is a crystalline resin such as polypropylene resin, which has a high resistance to heat, and when heated locally, it melts instantaneously and lowers in viscosity. These resins flow well into the gaps as they melt, creating a plastic muffler with high air tightness and high adhesion strength, and the muffler made because of the smoothness and flatness of the surfaces formed by the fusion of the parts bonded together. However, there is an advantage that a satisfactory appearance is obtained. Next, a suitable embodiment will be described with reference to FIGS. 2 to 5.

2 is a view showing an example of a plastic silencer manufactured by the method according to the present invention, which is composed of an intake portion 8, a passage 9 of a refrigerant, an expansion chamber 10, and a resonance chamber 13; .

The plastic muffler, shown in perspective in FIG. 2, features a suction part 8, an expansion chamber 10, a part of the passage 9 of the refrigerant, and a main body part 7-1 of the muffler comprising a resonance chamber 13, and a horseshoe shape. A pair of muffler sections 7-2 ^a and 7-2 ^b in the shape of a U-shape containing a part of the resonant chamber 13 and the passage 9 of the refrigerant with flange 11 It is included. Marked with the number 12 indicates the parts of the U-shaped silencer sections 7-2 ^a and 7-2 ^b joined to the main body section 7-1 of the silencer.

Fig. 3 shows a cross section taken along the line III-III in Fig. 2, and Fig. 4 shows a high airtightness and no plastic gauze in accordance with the present invention with reference to Fig. 3 and Fig. 4. A suitable method of fabricating a plastic silencer, such as the one described below.

As shown in FIG. 3, the U-shaped upper and lower silencer portions 7-2 ^a and 7-2 ^b are in close contact with the inner edge portions of the silencer portion to form a passage 9 for the refrigerant, and the upper portion 7 of the silencer. -2 ^a so that a gap is formed between the outer edge of the silencer and the flange 11-1 and the lower part of the silencer 7-2 ^{b and} the outer edge of the silencer and the flange and 11-2, and the inner edge of the silencer is numbered 14 They overlap each other so that they are neatly bonded together like places.

This clearance is to be of appropriate dimensions. Then, using the pressure jig 15, the outer edge and flange 11-2 of the upper part 7-2 ^a of the muffler and the outer edge and flange 11- 11 of the lower part 7-2 ^b of the muffler Press the upper part 7-2 ^a of the muffler in the direction of the lower part 7-2 ^b of the muffler over the entire surface of the passage 9 of the refrigerant so that the two are in close contact with each other. Then hot air, a temperature in the range of 370 ° C. to 410 °, is at the exit of the outer edge.

The flanges 11-1 and 11-2 are joined by fusion to form the flange 11. As a result, an airtight, airtight seal is made between the edge of the passage 9 of the refrigerant and the flanges 11-1 and 11-2 and also on their inner edge 14.

When two flanges are made in the outer edges of the muffler sections 7-2a and 7-2b, the plastic begins to melt at the ends of the outer protrusions of the flanges 11-1 and 11-2. Remy can be prevented. Since the strength of the outer edge portion and the flange 11-1 and the outer edge portion and the flange 11-2 are joined together by fusion is very high, it is difficult to fusion due to the concentration of stress and cracking occurs. Does not happen. The reason is that the inner edge of the passage 9 of the refrigerant formed by the close contact as indicated by the number 14 is pressurized from the outside during use, and the passage 9 of the refrigerant is almost equal to the atmospheric air pressure. .

One way to increase the speed of melting to reduce the time it takes to make flange 11 by joining the outer edges with flanges 11-1 and 11-2 is to reduce the thickness of each flange 11-1, 11-9. The thickness of the flange is made thinner than the thickness of the wall of the passage 9 of the refrigerant so as to melt and melt immediately as soon as hot air is shot. Also, pressurizing jig 15 will block the hot air while pressing the upper part 7-2a of the muffler towards the lower part 7-2b of the muffler and only melt the outer edges and the ends of the projections with flanges 11-1 and 11-2. Process the shape of press jig 15 to effectively fuse with high efficiency. This saves energy and prevents breakage or overall deformation of the muffler by fusion with minimal heat, thus making the muffler dimension accurate, precise and beautiful in appearance.

When the upper and lower parts of the silencer 7-2a and 7-2b overlap each other, the dimensions of the gap between the outer edges of the upper and lower parts of the silencer and the flanges 11-1 and 11-2 are changed appropriately. In addition, the inner edges of the refrigerant passage 9 (parts indicated at 14 in FIG. 4) are mutually selected by appropriately selecting the thickness of the walls of the refrigerant passage 9, and also by using plastic having an appropriate flexural modulus. As shown in FIG. 4, the airtight seal in the inner edge portion 14 of the refrigerant passage 9 isolating the resonance chamber 13 and the refrigerant passage 9, as shown in FIG. It can be ensured and withstands prolonged use.

The shape of the inner edge portion 14 of the passage 9 of the coolant can be modified into the required shape as shown in FIGS. 5A to 5C. As shown in Fig. 5A, the inner edge portions 14 each have a flat surface, and in Fig. 5B, the inner edge portions 16 are respectively tucked on the surface thereof. In addition, as shown in FIG. 5C, the inner edge portions 17 each have protrusions and depressions on their surfaces so as to engage with each other.

Improving the airtight seal of the inner edge of the refrigerant passage 9 by using a combination of the desired shapes by making the shape of the inner edge part different, and at the same time as the upper part of the silencer 7-2a and the silencer as described above The lower parts 7-2b of each other can be snapped into position when facing each other.

Any crystalline resin, such as polybutylene terephthalate resin, polyethylene terephthalate resin, polypropylene resin, poly ethersulfon resin, or fluorine resin, melts instantly when heated and has low viscosity. The resin can be used as the thermoplastic resin of the present invention. When these resins melt, they penetrate into the outer edges and the respective parts of the flanges to bond to each other, so that the outer edges can be completely sealed between the flanges 11-1 and 11-2 and the bond strength can be improved. You can make it bigger.

In addition, the melt combines between them to form a smooth surface. By reinforcing the resins using glass fiber, the flexural modulus of these resins can be increased, thus greatly improving the resistance to deformation due to heat of the silencer and the accuracy of the dimensions, and on the other hand, the inner edge of the passage 9 of the refrigerant. When the parts are tightly coupled to each other, it is possible to promote a confidential seal. At the same time, the resistance to oil and refrigerant produced by the silencer can be increased when used in an electrically operated compressor in a space filled with oil and refrigerant.

When combining the edge of the silencer's main body 7-1 with the edge of the silencer's upper and lower parts 7-2a and 7-2b, as described above, It can be fused by the welding method used when joining the lower parts 7-2a and 7-2b.

As described above, according to the method according to the present invention, it can be seen that the plastic silencer having a complicated structure can be easily assembled by dividing the plastic silencer into a plurality of parts and molding them by injection molding in advance, and combining them with each other by welding.

The method according to the invention comprises the suction part of the refrigerant shell, the passage of the refrigerant, and the expansion chamber, and the resonance chambers by injection molding using a heat resistant thermoplastic resin and fusion bonding the injection molded parts with hot air. This makes it easy and inexpensive to make a complicated plastic silencer.

When the suction side silencer manufactured by the method according to the present invention is used in an electrically operated compressor, the temperature of the refrigerant can be drastically reduced as compared with that of the conventional metal silencer. Therefore, the efficiency of the compressor can be greatly improved, and more practical work of the compressor can be performed. The use of a compressor with a built-in plastic silencer manufactured by the method according to the present invention can significantly reduce electricity consumption when used in an electric refrigerator or a small air conditioner.

Claims (5)

A method for producing a plastic silencer for a hermetic compressor assembled by the following process. A), a process in which a flange made of plastic material thinner than the thickness of the silencer wall is formed into the upper and lower portions of the silencer formed at the edge portion. N). The process of superimposing the upper part of the muffler on the lower part of the muffler so that when the gap is formed between the edges and the flanges of the upper and lower parts of the muffler, the inner edges of the upper and lower parts of the muffler are closely aligned with each other. C). Using the pressure jig, press the flange of the outer edge of the upper part of the muffler and the flange of the outer edge of the lower part of the silencer and apply hot air to the outer end protruding from the outer edge of the upper and lower muffler parts to apply the hot air to the outer edge of the flange. Melting and fusion process. D). Coupling the silencer portion to the main body portion of the silencer by fusion. Crystalline resin is used as a material which manufactures said plastic silencer, The manufacturing method of Claim 1 plastic silencer characterized by the above-mentioned. The above-mentioned crystalline resin is reinforced with glass fiber, The manufacturing method of the plastic silencer of Claim 2 characterized by the above-mentioned. Manufacture of the first plastic muffler of claim 1 characterized in that the inner edges of the muffler, which are in close contact with each other when the upper part and the lower part of the muffler are bonded to each other, are tucked together. Way. When the upper part and the lower part of the muffler are combined with each other, the surfaces of the inner edges of the muffler, which are brought into close contact with each other, are joined by protrusions and recessed portions. Manufacturing method of plastic silencer.

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