Compressor cylinder and manufacturing method thereof, pump body assembly, compressor and electric appliance

Abstract

The invention provides a compressor air cylinder and a manufacturing method thereof, a pump body assembly, a compressor and an electric appliance. The compressor air cylinder comprises an air cylinder body, the air cylinder body is provided with a compression cavity, an empty groove is formed between the compression cavity and the outer wall of the air cylinder body, and the empty groove extends in the circumferential direction of the compression cavity; at least one reinforcing rib extending in the radial direction of the air cylinder body is arranged in the empty groove in the axial direction of the air cylinder body. The empty groove is filled with a foamed plastic layer, and the foamed plastic layer wraps the reinforcing ribs. By means of the compressor air cylinder, the problems that the noise reduction heat insulation materials in the compressor air cylinder loosen and fall off can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular, to a compressor cylinder, a pump body assembly using the compressor cylinder, a compressor using the pump body assembly, an electrical appliance using the compressor, and a method for manufacturing the compressor cylinder. Background Art

[0002] The rotary fully enclosed compressor has been widely used in the fields of air conditioning and heat pumps due to its advantages of high compression efficiency, small size, and low noise. The compressor with the existing structure adopts a clearance fit between the cylinder and the shell, and a large gap is left between the wall of the cylinder and the inner wall of the shell. In the actual operation of the fully enclosed rotary compressor, when the pump body compresses the refrigerant gas, the pressure and temperature of the compressed refrigerant will increase significantly. Then the high-temperature and high-pressure refrigerant is discharged into the closed casing of the compressor. At the same time, the motor will also generate a large amount of loss heat during operation, which will cause the internal temperature of the casing of the fully enclosed compressor to be always in a high state. The temperature can reach up to 150°C, which makes the gap between the wall of the cylinder and the inner wall of the shell surrounded by a mixed medium of high-temperature refrigerant and refrigeration oil. The temperature of the metal pump body parts in the compressor will rise. The temperature increase will not only heat the low-temperature refrigerant gas entering the suction chamber of the compressor pump body from the system, but also cause the low-temperature refrigerant gas to expand due to the heat, resulting in a reduction in the amount of refrigerant gas entering the suction chamber of the pump body. In addition, it is not conducive to the heat dissipation of the pump body, resulting in overheating of the low-temperature suction of the compressor, excessive exhaust temperature, increased power consumption, and decreased efficiency. The compressor power loss caused by overheating of the compressor suction accounts for about 5% of the total power loss of the compressor, and it will also endanger the insulation safety and operation reliability of the internal motor. These are among the main reasons for the decline in the energy efficiency level and reliability of the compressor.

[0003] Moreover, as the country's requirements for the energy efficiency level of refrigeration cycle devices are getting higher and higher, compressors are gradually developing towards miniaturization and high speed. The operating frequency of miniaturized compressors is also gradually increasing from high frequency (100-120Hz) to ultra-high frequency (≥150Hz), thereby achieving the same cooling capacity per unit time as that of large-displacement compressors when running at medium frequency or high frequency by increasing the operating frequency of small-displacement compressors. However, as the compressor operating speed increases, the temperature inside the fully enclosed compressor casing will be much higher than 150°C, and the temperature can even reach 200°C, which will cause the low-temperature suction air entering the compressor to overheat more seriously, further increase power consumption, and higher exhaust temperature, and the efficiency of the compressor will drop more significantly. At the same time, at higher temperatures, the plastic insulation and insulation coating of the motor in the compressor are more likely to fail, and the motor insulation safety and operation reliability are also greatly reduced.

[0004] Therefore, in order to improve the refrigeration performance of the compressor, the cylinder must be separated from the high-temperature environment inside the compressor and the thermal resistance at the gap between the cylinder and the inner wall of the shell must be increased to prevent the high-temperature environment inside the compressor from heating the refrigerant gas entering from the cylinder suction port, so as to solve the problem of compressor suction overheating, increase the intake amount of refrigerant gas, and thus improve the operating efficiency of the compressor.

[0005] In an existing compressor, a honeycomb-shaped porous ceramic structure is embedded in the cavity between the inner and outer walls of the cylinder. This structural layout can solve the problem of compressor suction overheating, and can also block and weaken the friction mechanical noise generated inside the pump body, thereby achieving the purpose of reducing compressor noise and improving compressor performance. However, ceramics are brittle materials, and the compressor is accompanied by mechanical vibrations during operation. Therefore, after long-term operation, the honeycomb-shaped porous ceramic structure and the cylinder will become loose and fall off. The structure will vibrate together with the compressor and produce a violent resonance effect, which also increases the noise excitation source. At the same time, its cavity structure only has a supporting structure at the bottom, which reduces the elastic modulus of the cylinder, deteriorates the ability to resist deformation, and is more seriously deformed under high-frequency and high-temperature conditions.

[0006] Therefore, a more optimized compressor structure needs to be considered. Summary of the invention

[0007] The first object of the present invention is to provide a compressor cylinder that can avoid the problem of loosening and falling off of noise reduction and heat insulation materials in the compressor cylinder.

[0008] A second object of the present invention is to provide a pump body assembly that can avoid the problem of loosening and falling off of noise reduction and heat insulation materials in the compressor cylinder.

[0009] A third object of the present invention is to provide a compressor that can avoid the problem of loosening and falling off of noise reduction and heat insulation materials in the compressor cylinder.

[0010] A fourth object of the present invention is to provide an electrical appliance that can avoid the problem of loosening and falling off of noise reduction and heat insulation materials in the compressor cylinder.

[0011] A fifth object of the present invention is to provide a method for manufacturing a compressor cylinder that can avoid the problem of loosening and falling off of noise reduction and heat insulation materials in the compressor cylinder.

[0012] In order to achieve the above-mentioned first purpose, the compressor cylinder provided by the present invention includes a cylinder body, the cylinder body is provided with a compression chamber, a hollow groove is provided between the compression chamber and the outer wall of the cylinder body, and the hollow groove is extended along the circumferential direction of the compression chamber; in the axial direction of the cylinder body, at least one reinforcing rib extending along the radial direction of the cylinder body is provided in the hollow groove; the hollow groove is filled with a foam plastic layer, and the foam plastic layer covers the reinforcing rib.

[0013] As can be seen from the above scheme, the compressor cylinder of the present invention is provided with a slot filled with a foam plastic layer between the compression chamber and the outer wall of the cylinder body, and the foam plastic layer is first filled and then foamed, so as to form a foam plastic layer with a good covering effect between the reinforcing ribs, thereby effectively solving the problem of loosening and falling off. Moreover, the thermal conductivity of the foam plastic layer is low, and it has a good heat insulation effect. At the same time, the foam plastic layer can also absorb some mechanical noise (such as friction noise, impact noise, etc.), thereby reducing the noise of the entire compressor and improving the user experience.

[0014] In a further solution, in the radial direction of the cylinder body, the thickness t of the empty groove satisfies the following relationship: 0.25T≤t≤0.6T; wherein T is the thickness between the compression chamber and the outer wall.

[0015] It can be seen that the thickness t of the empty groove satisfies the following relationship: 0.25T≤t≤0.6T, which can avoid the situation where the hole groove 115 makes the cylinder 110 unable to resist deformation and meet the use requirements of the compressor.

[0016] In a further embodiment, the foam plastic layer includes at least one of polypropylene, polyethylene, polystyrene, polyurethane, PF material, polyvinyl chloride, ABS plastic, epoxy resin, phenolic resin, acrylic resin, polyurethane resin, polyethersulfone resin, silicone resin, organic fluorine resin and composite foam plastic layer.

[0017] In a further embodiment, the composite foam plastic layer is formed by mixing at least one of polypropylene, polyethylene, polystyrene, polyurethane, PF material, polyvinyl chloride, ABS plastic, epoxy resin, phenolic resin, acrylic resin, polyurethane resin, polyethersulfone resin, silicone resin, and organic fluorine resin with hollow glass microspheres.

[0018] It can be seen that the foam plastic layer can be made of a variety of materials to improve application scenarios.

[0019] In a further solution, the cylinder body is provided with an air intake hole, which is connected to the compression chamber; and a first heat-insulating coating is provided on the wall surface of the air intake hole.

[0020] It can be seen that the first heat-insulating coating is provided on the wall surface of the air intake hole, which can further insulate the air intake hole and the cylinder body.

[0021] In a further embodiment, the first thermal insulation coating includes at least one of a ceramic coating and a fluorocarbon coating.

[0022] It can be seen that the first thermal insulation coating using a ceramic coating or a fluorocarbon coating can improve the thermal insulation effect.

[0023] In order to achieve the above second purpose, the pump body assembly provided by the present invention includes a compressor cylinder, and the compressor cylinder adopts the above compressor cylinder.

[0024] In order to achieve the third objective, the compressor provided by the present invention includes a pump body assembly and a shell assembly. The pump body assembly is installed in the shell assembly, and the pump body assembly adopts the above-mentioned pump body assembly.

[0025] In a further solution, the compressor also includes a liquid distributor assembly, which is located outside the shell assembly; the liquid distributor assembly includes an air outlet pipe, which is connected to the air intake hole of the cylinder body through a sealing tube; the surface of the outer wall and / or the inner wall of the sealing tube is coated with a second thermal insulation coating.

[0026] It can be seen that the surface of the outer wall and / or inner wall of the sealed tube is coated with a second thermal insulation coating, which effectively prevents the high-temperature and high-pressure refrigerant gas in the cavity between the cylinder and the inner wall of the shell from heating the low-temperature refrigerant gas flowing through the sealed tube, thereby solving the problem of compressor suction overheating.

[0027] In a further embodiment, the second thermal insulation coating includes at least one of a ceramic coating and a fluorocarbon coating.

[0028] In order to achieve the fourth objective, the present invention provides an electrical appliance, including a compressor, wherein the compressor is the above-mentioned compressor.

[0029] In order to achieve the fifth purpose mentioned above, the manufacturing method of the compressor cylinder provided by the present invention includes: manufacturing a cylinder body so that the cylinder body forms a compression chamber, a hollow groove is provided between the compression chamber and the outer wall of the cylinder body, and the hollow groove is extended along the circumferential direction of the compression chamber; in the axial direction of the cylinder body, at least one reinforcing rib extending along the radial direction of the cylinder body is provided in the hollow groove; filling the hollow groove with foam plastic raw material, foaming the foam plastic raw material in the hollow groove to form a foam plastic layer, so that the foam plastic layer covers the reinforcing rib.

[0030] It can be seen from the above scheme that the manufacturing method of the compressor cylinder of the present invention provides a hollow groove filled with a foam plastic layer between the compression chamber and the outer wall of the cylinder body, and adopts the foam plastic layer that is first filled and then foamed, so as to form a foam plastic layer with a good covering effect between the reinforcing ribs, thereby effectively solving the problems of loosening and falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural cross-sectional view of a compressor embodiment of the present invention.

[0032] Figure 2 1 is a structural diagram of a pump body assembly in an embodiment of a compressor of the present invention.

[0033] Figure 3 It is a structural cross-sectional view of a pump body assembly in an embodiment of a compressor of the present invention.

[0034] Figure 4 1 is a structural exploded view of a pump assembly in an embodiment of a compressor of the present invention.

[0035] Figure 5 1 is a structural diagram of a compressor cylinder in an embodiment of a compressor of the present invention.

[0036] Figure 6 1 is a structural diagram of a compressor cylinder in an embodiment of a compressor of the present invention.

[0037] Figure 7 It is a structural cross-sectional view of a compressor cylinder in an embodiment of a compressor of the present invention.

[0038] Figure 8 1 is a structural diagram of a sealing tube in an embodiment of a compressor of the present invention.

[0039] Fig. 9 It is a comparison chart of the refrigeration capacity of the conventional compressor solution and the compressor of the present invention.

[0040] Fig.10 It is a noise comparison chart of the conventional compressor scheme and the compressor of the present invention.

[0041] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0042] Compressor Example:

[0043] like Figure 1 As shown, in this embodiment, the compressor includes a pump assembly 1, a motor assembly 2, a housing assembly 3 and a liquid distributor assembly 4. The pump assembly 1 and the motor assembly 2 are installed in the housing assembly 3, the pump assembly 1 and the motor assembly 2 are installed in coordination, and the liquid distributor assembly 4 is located outside the housing assembly 3. The pump assembly 1 is driven by the motor assembly 2 to operate.

[0044] See also Figure 2 , Figure 3 and Figure 4 The pump body assembly 1 includes a compressor cylinder 11, a rotor 12, a vane 13, a crankshaft 14, an upper bearing assembly 15, a lower bearing 16 and a muffler cover 17. The installation structure of the compressor cylinder 11, the rotor 12, the vane 13, the crankshaft 14, the upper bearing assembly 15, the lower bearing 16 and the muffler cover 17 is a well-known technology for those skilled in the art and will not be described in detail here.

[0045] See also Figure 5 , Figure 6 and Figure 7In this embodiment, the compressor cylinder 11 includes a cylinder body, and the cylinder body is provided with an air intake hole 111, a vane groove 112 and a compression chamber 113, and the air intake hole 111 and the vane groove 112 are both connected to the compression chamber 113. The vane 13 is installed in the vane groove 112.

[0046] In this embodiment, a first thermal insulation coating (not shown) is provided on the hole wall surface of the air intake hole 111. A first thermal insulation coating is provided on the hole wall surface of the air intake hole 111, which can insulate the air intake hole 111 and the cylinder body. The first thermal insulation coating includes at least one of a ceramic coating and a fluorocarbon coating. Preferably, the thermal conductivity of the first thermal insulation coating is lower than 15W / (m·K). The thickness of the first thermal insulation coating is 1.0mm to 5.0mm. The thermal conductivity of the first thermal insulation coating is lower than 15W / (m·K), and the thickness is 1.0mm to 5.0mm, which can effectively prevent the high-temperature and high-pressure refrigerant gas in the cavity between the cylinder and the inner wall of the shell from heating the low-temperature refrigerant gas flowing through the air intake hole 111, and the amount of low-temperature refrigerant gas entering the cylinder is further increased, the problem of compressor suction overheating is further solved, and the performance of the compressor is further improved.

[0047] In this embodiment, a slot 115 is provided between the compression chamber 113 and the outer wall 114 of the cylinder body, and the slot 115 is extended along the circumferential direction of the compression chamber 113. In the axial direction of the cylinder body, at least one reinforcing rib 116 extending along the radial direction of the cylinder body is provided in the slot 115. The slot 115 is filled with a foam plastic layer 118, and the foam plastic layer 118 covers the reinforcing rib 116.

[0048] In this embodiment, when manufacturing the compressor cylinder 11, the following steps are included: manufacturing a cylinder body, so that the cylinder body forms an air intake hole 111, a sliding vane groove 112 and a compression chamber 113, and a slot 115 is provided between the compression chamber 113 and the outer wall 114 of the cylinder body, and the slot 115 is extended along the circumference of the compression chamber 113. In the axial direction of the cylinder body, at least one reinforcing rib 116 extending along the radial direction of the cylinder body is provided in the slot 115; filling the slot 115 with a foamed plastic raw material, and foaming the foamed plastic raw material in the slot 115 to form a foamed plastic layer 118, so that the foamed plastic layer 118 covers the reinforcing rib 116.

[0049] The foamed plastic layer 118 formed by first filling the empty groove 115 with unfoamed foamed plastic raw materials and foaming the empty groove 115 fills the empty groove 115, and then contacts and clamps with the wall surface of the empty groove 115. The foamed foamed plastic layer 118 also grows toward both ends of the empty groove 115 in an unlimited axial direction, and finally the two ends growing out of the cylinder body are cut off, thereby obtaining the foamed plastic layer 118. After foaming, the foamed plastic layer 118 can effectively cover the reinforcing ribs 116, and the reinforcing ribs 116 can also play a good role in limiting and fixing the foamed plastic layer 118, so that even if the vibration generated by the long-term operation of the compressor will not cause the foamed plastic layer 118 to loosen or fall off, and the thermal insulation efficiency and vibration reduction and noise reduction performance will not be adversely affected.

[0050] In this embodiment, in the radial direction of the cylinder body, the thickness t of the empty groove 115 satisfies the following relationship: 0.25T≤t≤0.6T; wherein T is the thickness between the compression chamber 113 and the outer wall 114. The thickness t of the empty groove 115 satisfies the following relationship: 0.25T≤t≤0.6T, which can avoid the situation where the deformation resistance of the cylinder 110 due to the hole groove 115 cannot meet the use requirements of the compressor.

[0051] In this embodiment, the foam plastic layer 118 includes at least one of polypropylene, polyethylene, polystyrene, polyurethane, PF material, polyvinyl chloride, ABS plastic, epoxy resin, phenolic resin, acrylic resin, polyurethane resin, polyethersulfone resin, organic silicon resin, organic fluorine resin and composite foam plastic. The composite foam plastic is formed by mixing at least one of polypropylene, polyethylene, polystyrene, polyurethane, PF material, polyvinyl chloride, ABS plastic, epoxy resin, phenolic resin, acrylic resin, polyurethane resin, polyethersulfone resin, organic silicon resin and organic fluorine resin with hollow glass microspheres.

[0052] In this embodiment, the density of the foam plastic layer 118 is 0.1 g / cm 3 Up to 0.8g / cm 3 The foam plastic layer 118 with a lower density can have a larger porosity, which not only has a good heat insulation effect, but also effectively prevents the high-temperature and high-pressure refrigerant gas in the cavity between the cylinder and the inner wall of the shell from heating the refrigerant gas sucked into the cylinder. The amount of low-temperature refrigerant gas entering the cylinder increases, the problem of compressor suction overheating is solved, and the performance of the compressor is improved. Moreover, the connection part of the irregular non-orientation dislocation structure between the pores can also absorb more sound energy and vibration of the noise transmitted from the cylinder inside the pump body assembly 1, thereby achieving the effect of vibration reduction and noise reduction, and the noise and vibration of the compressor are reduced.

[0053] In this embodiment, the thermal conductivity of the foam plastic layer 118 is lower than 15W / (m·K), which can effectively form a good thermal resistance effect between the cylinder and the high-temperature cavity in the shell. The tensile strength of the foam plastic layer 118 is greater than 5.0MPa. The tensile strength of the foam plastic layer 118 is large, and even if the compressor falls accidentally or vibrates during long-term operation, the foam plastic layer 118 will not fall off, peel off, break, or other problems. The temperature resistance of the foam plastic layer 118 is higher than 200°C, which can reduce the aging failure caused by the high temperature of the compressor.

[0054] Depend on Figure 1 It can be seen that the liquid distributor assembly 4 includes an air outlet pipe 41, and the air outlet pipe 41 is connected to the air intake hole 111 of the cylinder body through the sealing pipe 5. In this embodiment, the sealing pipe 5 includes a first pipe section 51 and a second pipe section 52, the first pipe section 51 is pressed into the air intake hole 111 by interference fit, and the second pipe section 52 is welded to the air outlet pipe 41, and the diameters of the first pipe section 51 and the second pipe section 52 are set correspondingly according to the diameters of the air outlet pipe 41 and the air intake hole 111.

[0055] In this embodiment, the surface of the outer wall 114 and / or the inner wall of the sealed tube 5 is coated with a second thermal insulation coating (not shown). Preferably, the second thermal insulation coating includes at least one of a ceramic coating and a fluorocarbon coating. The thermal conductivity of the second thermal insulation coating is lower than 15W / (m·K). The thickness of the second thermal insulation coating is 1.0mm to 5.0mm. The surface of the outer wall 114 and / or the inner wall of the sealed tube 5 is coated with a second thermal insulation coating, which effectively prevents the high-temperature and high-pressure refrigerant gas in the cavity between the cylinder and the inner wall of the shell from heating the low-temperature refrigerant gas flowing through the sealed tube 5, thereby solving the problem of compressor suction overheating.

[0056] As can be seen from the above, the compressor cylinder 11 of the present invention is provided with a slot 115 filled with a foam plastic layer 118 between the compression chamber 113 and the outer wall 114 of the cylinder body, and the foam plastic layer 118 is first filled and then foamed, so as to form a foam plastic layer 118 with a good coating effect between the reinforcing ribs 116, thereby effectively solving the problem of loosening and falling off. Moreover, the foam plastic layer 118 has a low thermal conductivity and has a good heat insulation effect. At the same time, the foam plastic layer 118 can also absorb some mechanical noise (such as friction noise, impact noise, etc.), thereby reducing the noise of the entire compressor and improving the user experience.

[0057] See also Fig. 9 , Fig. 9 This is a comparison chart of the refrigeration capacity of a conventional compressor solution and the compressor of the present invention. After the performance test was carried out on the compressor, the refrigeration capacity of the compressor of the present invention was improved compared with the conventional compressor solution, especially the improvement of the high-frequency refrigeration capacity was the most obvious, so the performance of the compressor was improved and the refrigeration efficiency was improved. Fig.10 , Fig.10 This is a noise comparison chart between a conventional compressor solution and the compressor of the present invention. After performing noise testing on the compressor, the noise at each operating frequency is greatly reduced, and the user experience is improved.

[0058] Electrical appliance embodiment:

[0059] In this embodiment, the electrical appliance includes a compressor, and the compressor adopts the compressor of the above embodiment. The electrical appliance may be a refrigerator, an air conditioner, an air purifier, or other electrical appliances that require a compressor.

[0060] It should be noted that the above are only preferred embodiments of the present invention, but the design concept of the invention is not limited thereto, and any non-substantial modifications made to the present invention using this concept also fall within the protection scope of the present invention.

Claims

1. A compressor cylinder, comprising a cylinder body, wherein the cylinder body is provided with a compression chamber, a slot is provided between the compression chamber and an outer wall of the cylinder body, and the slot is extended along the circumferential direction of the compression chamber; in the axial direction of the cylinder body, at least one reinforcing rib extending along the radial direction of the cylinder body is provided in the slot; characterized in that: The empty groove is filled with a foam plastic layer, and the foam plastic layer covers the reinforcing rib.

2. The compressor cylinder according to claim 1, characterized in that: In the radial direction of the cylinder body, the thickness t of the slot satisfies the following relationship: 0.25T≤t≤0.6T; Wherein, T is the thickness between the compression chamber and the outer wall.

3. The compressor cylinder according to claim 1, characterized in that: The foam plastic layer includes at least one of polypropylene, polyethylene, polystyrene, polyurethane, PF material, polyvinyl chloride, ABS plastic, epoxy resin, phenolic resin, acrylic resin, polyurethane resin, polyether sulfone resin, organic silicon resin, organic fluorine resin and composite foam plastic layer.

4. The compressor cylinder according to claim 3, characterized in that: The composite foam plastic layer is formed by mixing at least one of polypropylene, polyethylene, polystyrene, polyurethane, PF material, polyvinyl chloride, ABS plastic, epoxy resin, phenolic resin, acrylic resin, polyurethane resin, polyethersulfone resin, silicone resin, and organic fluorine resin with hollow glass microspheres.

5. The compressor cylinder according to any one of claims 1 to 4, characterized in that: The cylinder body is provided with an air suction hole, and the air suction hole is communicated with the compression chamber; The hole wall surface of the air suction hole is provided with a first heat insulation coating.

6. The compressor cylinder according to claim 5, characterized in that: The first thermal insulation coating includes at least one of a ceramic coating and a fluorocarbon coating.

7. A pump assembly comprising a compressor cylinder, characterized in that: The compressor cylinder adopts the compressor cylinder according to any one of claims 1 to 6.

8. A compressor, comprising a pump assembly and a housing assembly, wherein the pump assembly is installed in the housing assembly, characterized in that: The pump body assembly adopts the pump body assembly as claimed in claim 7.

9. The compressor according to claim 8, characterized in that: The compressor further comprises a liquid distributor assembly, wherein the liquid distributor assembly is located outside the housing assembly; The liquid distributor assembly comprises an air outlet pipe, and the air outlet pipe is connected with the air intake hole of the cylinder body through a sealing pipe; The surface of the outer wall and / or the inner wall of the sealing tube is coated with a second heat-insulating coating.

10. The compressor according to claim 9, characterized in that: The second thermal insulation coating includes at least one of a ceramic coating and a fluorocarbon coating.

11. An electrical appliance, comprising a compressor, characterized in that: The compressor is the compressor according to any one of claims 8 to 10.

12. A method for manufacturing a compressor cylinder, comprising: A cylinder body is manufactured so that the cylinder body forms a compression chamber, a hollow groove is provided between the compression chamber and the outer wall of the cylinder body, and the hollow groove is extended along the circumferential direction of the compression chamber; in the axial direction of the cylinder body, at least one reinforcing rib extending along the radial direction of the cylinder body is provided in the hollow groove; Characterized in that the method further comprises: The empty groove is filled with a foamed plastic material, and the foamed plastic material is foamed in the empty groove to form a foamed plastic layer, so that the foamed plastic layer covers the reinforcing rib.

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