Method for removing foreign matters on surface of metal part of high-voltage switch

Abstract

The invention relates to a high-voltage switch metal part surface foreign matter removing method, and belongs to the technical field of electronic part surface treatment. According to the method for removing the foreign matter on the surface of the electronic part, firstly, the part to be treated is sequentially subjected to cleaning agent cleaning and ultrasonic cleaning, dirt such as dust and greasy dirt with low adhesive force on the surface of the part is removed, and dirt such as dust and greasy dirt in gaps or gaps on the surface of the part or foreign matter with high adhesive force is removed; and finally, preparing a strippable coating on the surface of the cleaned part, removing the strippable coating on the surface of the part, and further removing foreign matters adhered to the surface of the part through the strippable coating, so that the foreign matters on the surface of the electronic part are effectively removed. According to the method for removing the foreign matter on the surface of the electronic part, the foreign matter on the surface of the part can be effectively removed, the risk of discharging of the part in the assembly and actual operation process due to the existence of the metal foreign matter is avoided, and the rework rate or the maintenance rate is reduced.

Description

Technical Field

[0001] The invention relates to a method for removing foreign matter on the surface of a high-voltage switch metal part, belonging to the technical field of electronic part surface treatment. Background Art

[0002] Gas-insulated metal-enclosed switchgear (GIS) is a major component of high-voltage switchgear. The shapes and structures of its conductors, shielding covers and other parts are complex, and are usually made by aluminum alloy casting, sandblasting / shot blasting, machining, surface grinding and other processes. Affected by the manufacturing process and production environment, foreign objects such as fine metal wires and metal chips will adhere to the surface of the finished parts. In order to meet the requirements of the assembly process for the cleanliness of the parts, the various parts of the gas-insulated metal-enclosed switchgear need to be cleaned before assembly to remove foreign objects. At present, the conventional cleaning process (scouring pad + water + detergent) is mainly used for removal. However, due to the strong adhesion of fine metal chips on the surface of the parts and the complex structure of the parts, foreign objects in the inner cavity, corners and other parts are not easy to remove. The existing conventional cleaning process cannot completely remove foreign objects on the surface of the parts. Since the foreign objects inside the parts are not cleaned up, metal particles or impurities exist inside the assembled GIS equipment. These metal particles or impurities will gradually move to the high field strength area under the action of the AC electric field, and finally move to the weak field strength area to cause internal flashover. Foreign matter can cause discharge in the space inside the shell, and can also cause discharge along the surface of insulating parts such as pot insulators and supporting insulating tubes. After the discharge of parts or GIS equipment is found, the parts or GIS equipment will be reworked or repaired, which will not only increase the production cost, but also affect the product quality. In order to solve the problem of rework or repair caused by the presence of foreign matter on the surface of parts of gas-insulated metal-enclosed combined electrical appliances, Chinese patent document CN112713026A discloses a method for treating foreign matter on the surface of parts in the arc extinguishing chamber of a circuit breaker. The surface foreign matter treatment method includes the following steps: sandblasting or shot blasting the parts to be treated, followed by degreasing, pickling, ultrasonic cleaning, passivation and high-pressure water cleaning, and then preparing a coating on the non-conductive connection parts of the parts. The patent document can effectively solve the problem of residual foreign matter on the surface of internal parts and improve the surface quality of parts through multiple processing links such as shot blasting, degreasing, pickling, ultrasonic cleaning, passivation, and high-pressure water cleaning. After surface coating treatment, it can ensure that no foreign matter is scattered during operation, effectively reducing discharge accidents caused by the presence of metal foreign matter. However, this treatment method is complicated to operate and cannot completely remove metal foreign matter on the surface of aluminum alloy castings or in the inner cavity of complex structures. Because the material of aluminum alloy castings is relatively soft, some metal foreign matter is embedded in its surface and has strong adhesion. High-pressure water cleaning cannot completely remove these foreign matter. During high-pressure water cleaning, the water column sprays in a straight line and cannot effectively clean foreign matter in complex structures such as corners or grooves. At the same time, the surface coating is easily peeled off as the use time increases, which causes the uncleaned foreign matter to be exposed, leading to discharge accidents inside the shell. Summary of the invention

[0003] The purpose of the present invention is to provide a method for removing foreign matter from the surface of metal parts of a high-voltage switch, which can solve the problem of poor cleaning effect when dealing with foreign matter on the surface of parts of a gas-insulated metal-enclosed switchgear.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the method for removing foreign matter on the surface of the metal parts of the high-voltage switch of the present invention is:

[0005] A method for removing foreign matter from the surface of a high-voltage switch metal part comprises the following steps: firstly, the part to be processed is sequentially cleaned and dried, then a peelable coating is prepared on the surface of the part, and finally the peelable coating on the surface of the part is removed; the cleaning treatment is to sequentially clean the part to be processed with a cleaning agent and ultrasonic cleaning; the cleaning agent is an alkali solution or a neutral degreasing agent.

[0006] The method for removing foreign matter on the surface of metal parts of a high-voltage switch of the present invention first sequentially cleans the parts to be processed with a detergent and ultrasonic cleaning to remove dust, oil stains and other stains with weak adhesion on the surface of the parts and remove dust, oil stains and other stains or foreign matter with strong adhesion in the gaps or crevices on the surface of the parts, and finally prepares a strippable coating on the surface of the parts after the cleaning treatment, and removes the strippable coating on the surface of the parts, and further removes foreign matter adhering to the surface of the parts through the strippable coating, thereby achieving effective removal of foreign matter on the surface of electronic parts. When the method for removing foreign matter on the surface of electronic parts of the present invention is used to remove various parts of a gas-insulated metal-enclosed switchgear (GIS), foreign matter on the surface of the parts can be effectively removed, and the risk of discharge of parts or GIS equipment during assembly and actual operation due to the presence of metal foreign matter can be avoided, thereby reducing the rework rate or maintenance rate, effectively improving product quality, and reducing the rework labor cost and parts loss caused by product discharge.

[0007] The treated parts are cleaned with a detergent to remove dirt, oil and other stains that are not strongly adhered to the surface of the parts. Preferably, the pH of the alkali solution is 9 to 12. For example, the pH of the alkali solution is 10 to 12. Preferably, the alkali solution is mainly composed of water and alkali metal hydroxide. For example, the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution. In order to reduce costs, preferably, the alkali solution is a sodium hydroxide solution.

[0008] Preferably, the cleaning agent is an alkaline solution, and the cleaning with the cleaning agent is to perform alkaline cleaning on the parts to be processed.

[0009] Preferably, the cleaning agent is an alkaline solution, the pH of the alkaline solution is 9-11, and the cleaning time of the cleaning agent is 2-3 minutes; the pH of the alkaline solution is greater than 11 and not less than 12, and the cleaning time of the cleaning agent is not less than 50 seconds. Further preferably, the cleaning agent is an alkaline solution, the pH of the alkaline solution is 10-11, and the cleaning time of the cleaning agent is 2-3 minutes.

[0010] Degreasing agent is a complex mixture of organic and inorganic chemicals with water as the matrix. It is a new type of industrial degreasing agent developed using the principles of "emulsification" and "saponification". Degreasing agent is mainly prepared from a variety of surfactants and builders. Neutral degreasing agents used for cleaning electronic parts are suitable for the present invention. Preferably, the neutral degreasing agent is mainly composed of surfactants, solubilizers, builders, inorganic salts, alkaline compounds, complexing agents and water; the surfactant is an alkali metal salt of dodecylbenzenesulfonate and an alkali metal salt of dodecyl sulfate; the solubilizer is ethanol and isopropanol; the builder is an alkali metal pyrophosphate; the inorganic salt is an alkali metal carbonate and an alkali metal bicarbonate; the alkaline compound is sodium hydroxide and saponified oils and fats; the complexing agent is disodium ethylenediaminetetraacetic acid and an alkali metal salt of citrate.

[0011] Preferably, the alkali metal salt of dodecylbenzene sulfonate is sodium dodecylbenzene sulfonate or potassium dodecylbenzene sulfonate; the alkali metal salt of dodecyl sulfate is sodium dodecyl sulfate or potassium dodecyl sulfate; the alkali metal salt of pyrophosphate is sodium or potassium pyrophosphate; the alkali metal carbonate is sodium carbonate; the alkali metal bicarbonate is sodium bicarbonate; and the alkali metal salt of citrate is sodium citrate.

[0012] Preferably, the mass ratio of the surfactant, solubilizing agent, builder, inorganic salt, alkaline compound, complexing agent and water is (0.1-0.5):(1-3):(0.1-1):(0.1-0.2):(7-9):(0.1-0.5):(85-90). For example, the mass ratio of the surfactant, solubilizing agent, builder, inorganic salt, alkaline compound, complexing agent and water is 0.5:2:1:0.1:8:0.4:88.

[0013] Preferably, the cleaning agent is a neutral degreasing agent, and the cleaning with the cleaning agent is performed by immersing the parts to be processed in the neutral degreasing agent.

[0014] Preferably, the cleaning agent is a neutral degreasing agent, and the cleaning time of the cleaning agent is not less than 15 minutes.

[0015] In order to reduce costs, preferably, the cleaning process is performed at room temperature.

[0016] In order to remove the cleaning agent on the surface of the parts, preferably, the cleaning method further comprises the following steps: washing the parts cleaned with the cleaning agent with water, and then performing the ultrasonic cleaning.

[0017] Ultrasonic cleaning of the parts to be processed can further remove dirt such as dust, oil and other stains in the gaps or crevices on the surface of the parts or foreign matter with strong adhesion. Preferably, the frequency of the ultrasonic wave used in the ultrasonic cleaning is 30 to 50 kHz. If the frequency of the ultrasonic wave is too high, the wavelength will be shortened and the cavitation effect will be weakened, thereby reducing the cleaning efficiency. If the frequency of the ultrasonic wave is too low, the noise will be greater, and the noise harm to the working environment will be greater.

[0018] Preferably, the power of the ultrasonic wave used in the ultrasonic cleaning is 100 to 1000 W. For example, the power of the ultrasonic wave used in the ultrasonic cleaning is 800 to 1000 W. Too much ultrasonic wave power will increase energy consumption and cost, while too little ultrasonic wave power will result in poor cleaning effect.

[0019] Preferably, the ultrasonic cleaning time is 3 to 5 minutes. If the ultrasonic cleaning time is too long, it will increase energy consumption and cost. If the ultrasonic cleaning time is too short, it will not be able to effectively remove foreign matter in the pores or gaps on the surface of the part, or it will not be able to effectively reduce the bonding force between the foreign matter and the surface of the part, so that the peelable coating cannot effectively adhere to and remove foreign matter.

[0020] Preferably, the cleaning agent used in the ultrasonic cleaning is water. Using water as the cleaning agent for ultrasonic cleaning is not only inexpensive, but also does not introduce other chemical substances.

[0021] Ultrasonic cleaning can remove foreign matter attached to the surface of parts. In order to further remove foreign matter attached to the surface of parts after ultrasonic cleaning, preferably, the cleaning method also includes the following steps: washing the parts after ultrasonic cleaning with water to complete the cleaning process.

[0022] Preferably, the material of the high-voltage switch metal parts is aluminum alloy, steel or copper. Aluminum alloy is relatively soft, and it is difficult to clean metal foreign matter attached to aluminum alloy. The cleaning method of the present invention can effectively remove metal foreign matter attached to aluminum alloy.

[0023] Preferably, the high-voltage switch metal parts are metal parts that make up a gas-insulated metal-enclosed switchgear. Most of the metal parts that make up a gas-insulated metal-enclosed switchgear are made of aluminum alloy, and some parts are made of steel, copper or non-metal, etc. However, foreign matter attached to materials other than aluminum alloy is easier to remove.

[0024] Preferably, the strippable coating is made of strippable paint.

[0025] Strippable paint, also known as strippable coating, is an isolation product with temporary protective function. It has the characteristics of tough film formation, acid and alkali salt spray corrosion resistance, waterproof, moisture-proof and scratch-resistant, and the paint film has the characteristics of firm adhesion and can be peeled off at any time. It is mainly used in the local electroplating process of metals such as stainless steel and aluminum alloy to provide temporary protection for the metal surface. In the present invention, the strippable paint is a water-based strippable paint or a solvent-based strippable paint. The strippable paint can be a commercially available product. Preferably, the strippable paint is T-3A strippable coating produced by Northwest Rubber and Plastic Research Institute Design Co., Ltd. The experimental results show that the strippable paint has good wettability to the surface of metal parts that constitute the gas-insulated metal-enclosed combination electrical appliance, and ensures that the strippable paint can penetrate into the gaps or pores on the surface of the parts. In addition, the strippable paint can ensure that the adhesion between the strippable coating and the surface of the part to be treated is in an appropriate range. When the adhesion between the strippable coating and the surface of the part to be treated is too small, foreign matter on the surface of the part cannot be effectively adhered. When the adhesion between the strippable coating and the surface of the part to be treated is too large, the coating cannot be completely peeled off from the surface of the part, resulting in coating residue, which affects the cleanliness of the surface of the part.

[0026] Preferably, the method for preparing a strippable coating on the surface of a cleaned part comprises the following steps: coating the surface of the cleaned part with a strippable coating. In order to ensure that the strippable coating can be completely coated on each surface of the part, preferably, the coating method is dip coating.

[0027] Preferably, the thickness of the peelable coating is 0.2 to 0.5 mm. If the peelable coating is too thin, it cannot effectively adhere to large-sized foreign objects on the surface of the part, or the adhesion between the peelable coating and the foreign objects is too low, or the peelable coating cannot be completely removed from the surface of the part later. If the peelable coating is too thick, the volatile components in the peelable paint will not evaporate completely, and the coating will not dry completely, making it difficult to peel off the peelable paint coating after drying, and it cannot be peeled off in one piece and continuously. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic flow chart of a method for removing foreign matter from the surface of a metal part of a high-voltage switch according to Embodiment 1 of the present invention;

[0029] Figure 2 A schematic diagram of a cleaning device used in the method for removing foreign matter from the surface of a high-voltage switch metal part of the present invention. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0031] Example 1

[0032] The schematic flow chart of the method for removing foreign matter from the surface of the metal parts of the high-voltage switch of this embodiment is as follows: Figure 1 As shown, in the specific implementation of this embodiment, with the help of Figure 2 The cleaning device shown in the figure is briefly introduced below. The cleaning device includes a hanger 1, an alkaline cleaning tank 2, a first clean water tank 3, an ultrasonic cleaning tank 4, a second clean water tank 5, a paint stripping tank 6 and a workbench 7. The hanger 1 is a crane for hanging electronic parts and can carry the parts forward, backward, upward and downward to carry the electronic parts to different positions for cleaning treatment;

[0033] The method for removing foreign matter from the surface of the metal parts of the high-voltage switch of this embodiment specifically comprises the following steps:

[0034] The conductor parts of the gas-insulated metal-enclosed switchgear are hung on a hanger 1, and then the parts are immersed in the alkaline solution in the alkaline washing tank 2 for alkaline washing. The alkaline solution used for alkaline washing is a sodium hydroxide solution with a pH of 11, and the alkaline washing time is 2 minutes. After the alkaline washing is completed, the parts are lifted from the alkaline washing tank 2, and the parts are moved and immersed in the clean water in the first clean water tank 3 for soaking for the first water washing to remove impurities such as alkaline solution and foreign matter on the surface of the parts. After the first water washing is completed, the parts are moved and immersed in the clean water in the ultrasonic cleaning tank 4 for ultrasonic cleaning. The frequency of the ultrasonic wave used for ultrasonic cleaning is 50kHz, the power is 800W, and the ultrasonic cleaning time is 3 minutes. After the ultrasonic cleaning is completed, The parts are moved and immersed in the clean water in the second clean water tank 5 for soaking and a second water washing to remove foreign matter and other impurities on the surface of the parts; after the second water washing, the parts are moved out of the second clean water tank 5 and dried, and then the parts are moved and immersed in the strippable paint in the strippable paint tank 6 to make a layer of strippable paint adhere to the surface of the parts, and then the parts are taken out of the strippable paint tank and dried naturally in the air at room temperature, and the strippable paint forms a layer of strippable coating on the surface of the parts; the strippable paint is T-3A electroplating special strippable paint produced by Northwest Rubber and Plastics Research Institute Design Co., Ltd., and the thickness of the strippable coating is 0.3mm; finally, the parts are transferred to the workbench 7, and the strippable coating on the surface of the parts is manually torn off to complete the removal of foreign matter on the surface of the electronic parts.

[0035] Example 2

[0036] The method for removing foreign matter from the surface of the metal parts of the high-voltage switch of this embodiment is as follows: Figure 2 The cleaning device shown in the figure is implemented, and specifically comprises the following steps:

[0037] Hang the shielding cover parts of the gas-insulated metal-enclosed combination electrical appliance on the hanger 1, and then immerse the parts in the alkaline solution in the alkaline washing tank 2 for alkali washing. The alkaline solution used for alkaline washing is a sodium hydroxide solution with a pH of 9, and the alkali washing time is 3 minutes; after the alkaline washing is completed, lift the parts from the alkaline washing tank 2, and move the parts and immerse them in the clean water in the first clean water tank 3 for immersion for the first water washing to remove impurities such as alkaline solution and foreign matter on the surface of the parts; after the first water washing is completed, move the parts and immerse them in the clean water in the ultrasonic cleaning tank 4 for ultrasonic cleaning. The frequency of the ultrasonic wave used for ultrasonic cleaning is 40kHz, the power is 1000W, and the ultrasonic cleaning time is 5 minutes; after the ultrasonic cleaning is completed, The parts are moved and immersed in the clean water in the second clean water tank 5 for soaking and a second water washing to remove foreign matter and other impurities on the surface of the parts; after the second water washing, the parts are moved out of the second clean water tank 5 and dried, and then the parts are moved and immersed in the strippable paint in the strippable paint tank 6 to make a layer of strippable paint adhere to the surface of the parts, and then the parts are taken out of the strippable paint tank and dried naturally in the air at room temperature, and the strippable paint forms a layer of strippable coating on the surface of the parts; the strippable paint is T-3A electroplating special strippable paint produced by Northwest Rubber and Plastics Research Institute Design Co., Ltd., and the thickness of the strippable coating is 0.5mm; finally, the parts are transferred to the workbench 7, and the strippable coating on the surface of the parts is manually torn off to complete the removal of foreign matter on the surface of the electronic parts.

[0038] Example 3

[0039] The method for removing foreign matter from the surface of the metal parts of the high-voltage switch of this embodiment is as follows: Figure 2 The cleaning device shown in the figure is implemented, and specifically comprises the following steps:

[0040] Hang the shielding cover parts of the gas-insulated metal-enclosed combination electrical appliance on the hanger 1, and then immerse the parts in the alkaline solution in the alkaline washing tank 2 for alkali washing. The alkaline solution used for alkaline washing is a sodium hydroxide solution with a pH of 12, and the alkali washing time is 50 seconds. After the alkaline washing is completed, lift the parts from the alkaline washing tank 2, and move the parts and immerse them in the clean water in the first clean water tank 3 for immersion for the first water washing to remove impurities such as alkaline solution and foreign matter on the surface of the parts. After the first water washing is completed, move the parts and immerse them in the clean water in the ultrasonic cleaning tank 4 for ultrasonic cleaning. The frequency of the ultrasonic wave used for ultrasonic cleaning is 40kHz, the power is 100W, and the ultrasonic cleaning time is 4 minutes. After the ultrasonic cleaning is completed, The parts are moved and immersed in the clean water in the second clean water tank 5 for soaking and a second water washing to remove foreign matter and other impurities on the surface of the parts; after the second water washing, the parts are moved out of the second clean water tank 5 and dried, and then the parts are moved and immersed in the strippable paint in the strippable paint tank 6 to make a layer of strippable paint adhere to the surface of the parts, and then the parts are taken out of the strippable paint tank and dried naturally in the air at room temperature, and the strippable paint forms a strippable coating on the surface of the parts; the strippable paint is T-3A electroplating special strippable paint produced by Northwest Rubber and Plastics Research Institute Design Co., Ltd., and the thickness of the strippable coating is 0.2mm; finally, the parts are transferred to the workbench 7, and the strippable coating on the surface of the parts is manually torn off to complete the removal of foreign matter on the surface of the electronic parts.

[0041] Example 4

[0042] The method for removing foreign matter from the surface of the metal parts of the high-voltage switch of this embodiment is as follows: Figure 2 The cleaning device shown in the figure is implemented, and specifically comprises the following steps:

[0043] Hang the conductor parts of the gas-insulated metal-enclosed combination electrical appliance on a hanger 1, and then immerse the parts in a neutral degreasing agent in an alkaline washing tank 2 for immersion, wherein the neutral degreasing agent is composed of a surfactant, a solubilizing agent, a builder, an inorganic salt, an alkali, a complexing agent and water, wherein the surfactant is sodium dodecylbenzene sulfonate, the solubilizing agent is ethanol, the builder is sodium pyrophosphate, the inorganic salt is sodium carbonate, the alkali is sodium hydroxide, the complexing agent is sodium citrate, the mass ratio of the surfactant, the solubilizing agent, the builder, the inorganic salt, the alkali, the complexing agent and water is 0.5:2:1:0.1:8:0.4:88, and the immersion time is 15 minutes; after the immersion is completed, lift the parts from the alkaline washing tank 2, move the parts and immerse them in the clean water in the first clean water tank 3 for immersion for the first water washing to remove impurities such as alkali solution and foreign matter on the surface of the parts; after the first water washing is completed, move the parts and immerse them in the clean water in the ultrasonic cleaning tank 4 for immersion. Ultrasonic cleaning, the frequency of the ultrasonic wave used for ultrasonic cleaning is 30kHz, the power is 800W, and the ultrasonic cleaning time is 4 minutes; after the ultrasonic cleaning is completed, the parts are moved and immersed in the clean water in the second clean water tank 5 for soaking for a second water washing to remove foreign matter and other impurities on the surface of the parts; after the second water washing is completed, the parts are moved out of the second clean water tank 5 and dried, and then the parts are moved and immersed in the strippable paint in the strippable paint tank 6 so that a layer of strippable paint adheres to the surface of the parts, and then the parts are taken out of the strippable paint tank and naturally dried in the air at room temperature, and the strippable paint forms a layer of strippable coating on the surface of the parts; the strippable paint is T-3A electroplating special strippable paint produced by Northwest Rubber and Plastics Research Institute Design Co., Ltd., and the thickness of the strippable coating is 0.3mm; finally, the parts are transferred to the workbench 7, and the strippable coating on the surface of the parts is manually torn off to complete the removal of foreign matter on the surface of the electronic parts.

[0044] Comparative Example 1

[0045] The method for removing foreign matter from the surface of the metal parts of the high-voltage switch of this comparative example is to use the following method: Figure 2 The cleaning device shown in the figure is implemented, and specifically comprises the following steps:

[0046] The same parts as those in Example 1 are hung on a hanger 1, and then the parts are immersed in the clean water in the ultrasonic cleaning tank 4 for ultrasonic cleaning. The frequency, power and time of the ultrasonic waves used for ultrasonic cleaning are respectively the same as the frequency, power and time of the ultrasonic waves used for ultrasonic cleaning in Example 1; after the ultrasonic cleaning is completed, the parts are moved and immersed in the clean water in the second clean water tank 5 for a second water washing (the method of the second water washing is the same as the method of the second water washing in Example 1) to remove foreign matter and other impurities on the surface of the parts; after the second water washing is completed, the parts are immersed in the alkali solution in the alkali washing tank 2 for alkali washing, and the alkali solution and the time of alkali washing used for alkali washing are respectively the same as the alkali solution and the time of alkali washing used for alkali washing in Example 1; after the alkali washing is completed, The parts are lifted from the alkali washing tank 2, and the parts are moved and immersed in the clean water in the first clean water tank 3 for the first water washing (the method of the first water washing is the same as the method of the first water washing in Example 1) to remove impurities such as alkali solution and foreign matter on the surface of the parts; after the first water washing, the parts are moved and immersed in the strippable paint in the strippable paint tank 6 (the strippable paint is the same as the strippable paint used in Example 1) so that a layer of strippable paint adheres to the surface of the parts, and then the parts are taken out of the strippable paint tank, and after cooling and drying at room temperature in the air, the strippable paint forms a layer of strippable coating on the surface of the parts (the thickness of the strippable coating is the same as the thickness of the strippable coating on the surface of the parts in Example 1); finally, the parts are transferred to the workbench 7, and the strippable coating on the surface of the parts is manually torn off to complete the removal of foreign matter on the surface of the electronic parts.

[0047] Comparative Example 2

[0048] The method for removing foreign matter from the surface of the metal parts of the high-voltage switch of this comparative example is to use the following method: Figure 2 The cleaning device shown in the figure is implemented, and specifically comprises the following steps:

[0049] The same parts as those in Example 1 are hung on a hanger 1, and then the parts are immersed in the alkali solution in the alkali washing tank 2 for alkali washing. The alkali solution and the time of alkali washing used in the alkali washing are respectively the same as the alkali solution and the time of alkali washing used in Example 1; after the alkali washing is completed, the parts are lifted from the alkali washing tank 2, and the parts are moved and immersed in the clean water in the first clean water tank 3 for the first water washing (the method of the first water washing is the same as the method of the first water washing in Example 1) to remove impurities such as alkali solution and foreign matter on the surface of the parts; after the first water washing is completed, the parts are moved and immersed in the strippable paint in the strippable paint tank 6 (the strippable paint is the same as the strippable paint used in Example 1) to make the surface of the parts sticky. A layer of peelable paint is attached, and then the part is taken out of the peelable paint pool. After cooling and drying in the air at room temperature, the peelable paint forms a peelable coating on the surface of the part (the thickness of the peelable coating is the same as the thickness of the peelable coating on the surface of the part in Example 1); then the part is immersed in the clean water in the ultrasonic cleaning pool 4 for ultrasonic cleaning. The frequency, power and time of the ultrasonic wave used for ultrasonic cleaning are the same as the frequency, power and time of the ultrasonic wave used for ultrasonic cleaning in Example 1; after the ultrasonic cleaning is completed, the part is transferred to the workbench 7, and the peelable coating on the surface of the part is manually torn off to complete the removal of foreign matter on the surface of the electronic part.

[0050] Comparative Example 3

[0051] The difference between the method for removing foreign matter from the surface of the high-voltage switch metal part of this comparative example and the method for removing foreign matter from the surface of the electronic part of Example 1 is that in the method for removing foreign matter from the surface of the electronic part of this comparative example, the thickness of the strippable coating is 0.1 mm.

[0052] Comparative Example 4

[0053] The difference between the method for removing foreign matter from the surface of the high-voltage switch metal parts of this comparative example and the method for removing foreign matter from the surface of the high-voltage switch metal parts of Example 1 is that in the method for removing foreign matter from the surface of the high-voltage switch metal parts of this comparative example, the thickness of the strippable coating is 0.6 mm.

[0054] Comparative Example 5

[0055] The only difference between the method for removing foreign matter on the surface of metal parts of a high-voltage switch in this comparative example and the method for removing foreign matter on the surface of metal parts of a high-voltage switch in Example 1 is that in the method for removing foreign matter on the surface of metal parts of a high-voltage switch in this comparative example, the strippable paint is T-8709 strippable paint produced by Northwest Rubber and Plastics Research and Design Institute Co., Ltd.

[0056] Experimental Example 1

[0057] In order to evaluate the effect of different cleaning methods on the removal of foreign matter on the surface of electronic parts, the parts treated by Examples 1-4 and Comparative Examples 1-5 were tested to observe whether there were any peelable coatings remaining on the surface of the parts, and the 3M tape adhesion test was performed to observe whether there were any foreign matter such as metal wires and fine metal chips on the tape to evaluate whether there were any foreign matter such as metal wires and fine metal chips remaining on the surface of the parts. The experimental results are shown in Table 1.

[0058] Table 1 Surface cleanliness of parts obtained by processing in Examples 1-4 and Comparative Examples 1-5

[0059]

[0060]

[0061] As shown in Table 1, when the methods of Examples 1-4 are used to treat the parts of the gas-insulated metal-enclosed switchgear, no peelable coating and metal foreign matter remain on the surface of the treated parts. However, when the steps in the cleaning method of the present invention are exchanged (Comparative Examples 1-2), the cleaning effect becomes worse, indicating that there is a certain synergy between the steps, and it is necessary to ensure that the steps are performed in a certain order to achieve the best cleaning effect. In addition, when the thickness of the peelable coating or the type of the peelable paint is changed, it will result in the inability to effectively peel off and remove the coating or the inability to effectively adhere to the coating to remove foreign matter.

[0062] Experimental Example 2

[0063] In order to evaluate the actual application effect of the parts treated by the method for removing foreign matter on the surface of the metal parts of the high-voltage switch of the present invention, the metal parts constituting the gas-insulated metal-enclosed switchgear are treated according to any of the removal methods in Examples 1-4, and then the parts are assembled to form a gas-insulated metal-enclosed switchgear. After a large number of experiments (the number of test samples is 20), the results show that the rework rate of the gas-insulated metal-enclosed switchgear assembled with the parts treated by the removal method of the present invention (the removal method of any of Examples 1-4) is less than 5% when in use due to discharge caused by foreign matter on the surface. The survey results show that after the foreign matter is removed from the parts, the surface of some non-metallic parts that have not been treated by the removal method of the present invention may also have metal foreign matter. At the same time, during the assembly process of the parts, the metal foreign matter in the environment may also re-adhere to the surface of the parts, thereby causing the assembled gas-insulated metal-enclosed switchgear to generate discharge when in use. In addition, the results of a large number of experiments (the number of test samples corresponding to each removal method is 20) show that when the gas-insulated metal-enclosed switchgear assembled with the parts treated by the removal method of Comparative Examples 1-5 is in use, the rework rate due to discharge caused by foreign matter on the surface is higher than 8%.

Claims

1. A method for removing foreign matter from the surface of a high-voltage switch metal part, characterized in that: The following steps are involved: First, the parts to be processed are sequentially cleaned and dried, then a peelable coating is prepared on the surface of the parts, and finally the peelable coating on the surface of the parts is removed; the cleaning treatment is to sequentially clean the parts with a cleaning agent and ultrasonic cleaning; the cleaning agent is an alkali solution or a neutral degreasing agent.

2. The method for removing foreign matter from the surface of a high-voltage switch metal part according to claim 1, characterized in that: The thickness of the peelable coating is 0.2-0.5 mm.

3. The method for removing foreign matter from the surface of a high-voltage switch metal part according to claim 1 or 2, characterized in that: The strippable coating is made of strippable paint.

4. The method for removing foreign matter from the surface of a high-voltage switch metal part according to claim 1, characterized in that: The pH value of the alkali solution is 9-12; the alkali solution mainly consists of water and alkali metal hydroxide.

5. The method for removing foreign matter from the surface of a high-voltage switch metal part according to claim 1 or 4, characterized in that: The cleaning agent is alkaline solution, and the cleaning with the cleaning agent is to perform alkaline cleaning on the parts to be processed; the cleaning agent is alkaline solution, the pH of the alkaline solution is 9-11, and the cleaning time of the cleaning agent is 2-3 minutes; the pH of the alkaline solution is greater than 11 and not less than 12, and the cleaning time of the cleaning agent is not less than 50 seconds.

6. The method for removing foreign matter from the surface of a high-voltage switch metal part according to claim 1, characterized in that: The neutral degreasing agent is mainly composed of a surfactant, a solubilizing agent, a builder, an inorganic salt, an alkaline compound, a complexing agent and water; the surfactant is an alkali metal salt of dodecylbenzenesulfonate and an alkali metal salt of dodecyl sulfate; the solubilizing agent is ethanol and isopropanol; the builder is an alkali metal pyrophosphate; the inorganic salt is an alkali metal carbonate and an alkali metal bicarbonate; the alkaline compound is sodium hydroxide and saponified oil; and the complexing agent is disodium ethylenediaminetetraacetic acid and an alkali metal citrate.

7. The method for removing foreign matter from the surface of a high-voltage switch metal part according to claim 1 or 6, characterized in that: The cleaning agent is a neutral degreasing agent, and the cleaning with the cleaning agent is to immerse the parts to be processed in the neutral degreasing agent; the cleaning agent is a neutral degreasing agent, and the cleaning time of the cleaning agent is not less than 15 minutes.

8. The method for removing foreign matter from the surface of a high-voltage switch metal part according to claim 1, characterized in that: The frequency of the ultrasonic wave used in the ultrasonic cleaning is 30-50kHz; the power of the ultrasonic wave used in the ultrasonic cleaning is 100-1000W; the time of the ultrasonic cleaning is 3-5min; and the cleaning agent used in the ultrasonic cleaning is water.

9. The method for removing foreign matter from the surface of a high-voltage switch metal part according to any one of claims 1-2, 4, 6, and 8, characterized in that: The cleaning method also includes the following steps: washing the parts cleaned with a cleaning agent with water, and then performing the ultrasonic cleaning; washing the parts cleaned with ultrasonic water to complete the cleaning process.

10. The method for removing foreign matter from the surface of a high-voltage switch metal part according to any one of claims 1-2, 4, 6, and 8, wherein the material of the high-voltage switch metal part is aluminum alloy, steel, or copper; and the high-voltage switch metal part is a metal part constituting a gas-insulated metal-enclosed switchgear.

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