A proportional valve lapping process

Abstract

This invention relates to a proportional valve grinding process for machining the hard metal sealing surfaces of the valve seat and valve core of a miniature proportional valve. The grinding process includes: Step 1, rough grinding: using 800-mesh diamond grinding paste, a grinding disc rotation speed of 150 r / min, and a grinding pressure of 0.8-1.0 MPa; Step 2, semi-finish grinding: using 1500-mesh diamond grinding paste, a grinding disc rotation speed of 100 r / min, and a grinding pressure of 0.5-0.7 MPa; Step 3, finish grinding: using 2000-mesh diamond grinding paste, a grinding disc rotation speed of 60 r / min, and a grinding pressure of 0.2-0.3 MPa. This application significantly improves sealing accuracy through stepped grinding and precise parameter control.

Description

Technical Field

[0001] This invention relates to the field of proportional valve manufacturing and processing technology, specifically to a high-precision grinding process for the sealing surface of a miniature proportional valve. Background Technology

[0002] The valve seat and valve core sealing surfaces of a miniature proportional valve are the core components for leak prevention. The flatness and smoothness of these sealing surfaces directly determine the valve's sealing performance. Current technologies for grinding the sealing surfaces of miniature proportional valves often employ ordinary manual grinding or simple equipment, which presents several problems: manual grinding relies on worker experience, resulting in uneven control of force and speed, leading to large deviations in the flatness of the sealing surface and easily causing localized unevenness; the selection of a single abrasive, directly proceeding from coarse grinding to fine grinding, fails to achieve the required precision smoothness of the sealing surface, leaving micro-gaps after assembly; and the lack of targeted cleaning and inspection after grinding allows abrasive residue to cause wear on the sealing surface, and it fails to detect defective products in a timely manner, easily leading to leakage problems after subsequent assembly. These problems result in poor sealing performance of miniature proportional valves, making it difficult to meet the requirements of precision scientific instruments and limiting the product's quality and application range.

[0003] Therefore, there is still room for improvement in the existing proportional valve grinding process. Summary of the Invention

[0004] To address the aforementioned shortcomings, the purpose of this invention is to provide a high-precision grinding process for the sealing surface of a miniature proportional valve, thereby solving the existing technical problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A proportional valve grinding process, wherein the grinding process is used for machining the hard metal sealing surfaces of the valve seat and valve core of a miniature proportional valve, the grinding process comprising: Step 1: Coarse grinding: Use 800-mesh diamond grinding paste, grinder rotation speed 150 r / min, grinding pressure 0.8-1.0 MPa; Step 2 Semi-finish grinding: Use 1500-mesh diamond grinding paste, grinder rotation speed 100 r / min, grinding pressure 0.5-0.7 MPa; Step 3: Fine grinding: Use 2000-mesh diamond grinding paste, grinder rotation speed 60r / min, grinding pressure 0.2-0.3MPa.

[0006] According to the proportional valve grinding process described in the embodiments of this application, the grinding process further includes: Step 4 special cleaning: secondary ultrasonic cleaning, the cleaning solution is anhydrous ethanol and deionized water, and hot air drying at 60-80℃.

[0007] According to the proportional valve grinding process described in the embodiments of this application, the grinding process further includes: Step 5 Finished product inspection: performing appearance inspection, flatness inspection and surface finish inspection.

[0008] According to the proportional valve grinding process described in the embodiments of this application, step 1 includes: Step 11 Abrasive selection: The cast iron grinding disc is pre-polished to a smooth surface, free of scratches and dents. Apply 800-grit diamond grinding paste evenly to the surface of the cast iron grinding disc. Step 12: Rough grinding operation: Fix the valve seat or valve core to be processed on the grinding fixture, ensuring that the workpiece is perpendicular to the grinding disc, start the grinding equipment, set the grinding disc speed to 150 r / min, control the grinding pressure at 0.8-1.0 MPa, use the circumferential grinding method, and continue grinding for 5-8 minutes. Step 13: Rough grinding inspection: After rough grinding, remove the machining allowance and surface burrs from the sealing surface to make the sealing surface initially flat, and control the flatness error within 0.005mm.

[0009] According to the proportional valve grinding process described in the embodiments of this application, step 2 includes: Step 21 Semi-finish grinding abrasive replacement: Clean the grinding disc and replace it with 1500-grit diamond grinding paste. Apply it evenly to ensure that the abrasive covers the entire working surface of the grinding disc. Step 22 Semi-fine grinding operation: Keep the workpiece clamping position unchanged, adjust the grinding parameters, reduce the grinding disc speed to 100 r / min, adjust the grinding pressure to 0.5-0.7 MPa, continue to use the circumferential grinding method, and grind for 8-10 minutes; Step 23 Semi-fine grinding inspection: After semi-fine grinding, the grinding marks left by coarse grinding are eliminated, and the flatness of the sealing surface is further improved. The flatness error is controlled within 0.003mm, and the surface finish reaches Ra0.1μm.

[0010] According to the proportional valve grinding process described in the embodiments of this application, step 3 includes: Step 31: Selection of abrasive for fine grinding: After cleaning the grinding disc, apply a small amount of 2000-grit diamond grinding paste evenly to avoid scratching the sealing surface due to excessive abrasive. Step 32 Fine grinding operation: Adjust the grinding disc speed to 60r / min, reduce the grinding pressure to 0.2-0.3MPa, adopt a slow speed and light pressure grinding method, and grind for 10-15 minutes. During this period, add a small amount of anhydrous ethanol to the grinding surface every 3 minutes to lubricate and cool it down. Step 33 Fine grinding inspection: After fine grinding, the sealing surface reaches the design accuracy, with a flatness error ≤0.001mm, a surface finish ≥Ra0.05μm, and no scratches, pits, or missing corners on the sealing surface.

[0011] According to the proportional valve grinding process described in the embodiments of this application, step 4 includes: Step 41 Initial cleaning: Place the ground workpiece into an ultrasonic cleaner, add anhydrous ethanol as the cleaning solution, set the ultrasonic power to 200W, and the cleaning time to 10 minutes to remove the grinding paste and metal shavings adhering to the surface. Step 42 Fine cleaning: Take out the workpiece after the initial cleaning, rinse the surface with deionized water, and then put it into new anhydrous ethanol for ultrasonic cleaning again for 5 minutes to ensure that there is no abrasive residue. Step 43 Drying: Place the cleaned workpiece into a hot air drying oven, set the temperature to 60-80℃, and dry for 15 minutes. After drying, remove it and place it in a dust-free container for later use to avoid secondary contamination.

[0012] According to the proportional valve grinding process described in the embodiments of this application, step 5 includes: Step 51: Visual inspection: Use a magnifying glass to observe the sealing surface and confirm that there are no scratches, pits, abrasive residues or other visual defects. Step 52 Precision Inspection: The flatness of the sealing surface is checked using a flatness tester, and the smoothness is checked using a surface roughness tester. If both indicators meet the design requirements, the product is considered qualified. Unqualified products are returned to the grinding process for further processing.

[0013] The purpose of this application is to provide a high-precision grinding process for the sealing surface of a miniature proportional valve. By standardizing the grinding process, precisely controlling the grinding parameters, and using dedicated cleaning and testing steps, high-precision machining of the sealing surface is achieved, improving the flatness and smoothness of the sealing surface, reducing the sealing surface clearance, thereby reducing the leakage of the miniature proportional valve, improving the sealing reliability of the product, and making the machining process more standardized, easier to operate, and suitable for mass production. The grinding process of this application is applicable to the machining of the valve seat and valve core sealing surfaces of miniature proportional valves used in precision instruments such as gas chromatographs and mass spectrometers, improving the sealing surface fit accuracy and leakage prevention performance.

[0014] Due to the adoption of the above technical features, this invention has the following advantages and positive effects compared with the prior art: First, this application significantly improves sealing accuracy through stepped grinding and precise parameter control; Secondly, the parameters for each step in this application are clear and the process is standardized, allowing staff to get started quickly and reducing processing difficulty. Third, the unique cleaning and testing steps in this application thoroughly remove abrasive residues, improving the product processing qualification rate.

[0015] Of course, implementing any specific embodiment of the present invention does not necessarily have all of the above technical effects at the same time. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the proportional valve grinding process of this application. Detailed Implementation

[0017] The following describes several preferred embodiments of the present invention in detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the present invention. To provide the public with a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments, but those skilled in the art will fully understand the present invention without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of the present invention, well-known methods, processes, procedures, elements, etc., are not described in detail.

[0018] Please refer to Figure 1 The overall process of this application is divided into five steps: rough grinding, semi-fine grinding, fine grinding, special cleaning, and finished product testing. Each step has standardized operation and clear parameters. By standardizing the grinding process, accurately controlling the grinding parameters, and using special cleaning and testing steps, high-precision machining of the sealing surface is achieved, improving the flatness and smoothness of the sealing surface, reducing the sealing surface clearance, thereby reducing the leakage of the micro proportional valve and improving the sealing reliability of the product. The grinding process of this application is applicable to the machining of the valve seat and valve core sealing surfaces of micro proportional valves used in precision instruments such as gas chromatographs and mass spectrometers, improving the sealing surface fitting accuracy and leakage prevention performance.

[0019] This application provides a proportional valve grinding process, which is used for machining the hard metal sealing surfaces of the valve seat and valve core of a miniature proportional valve. The grinding process includes: Step 1: Rough Grinding Treatment: Use 800-mesh diamond grinding paste, grinder rotation speed 150 r / min, grinding pressure 0.8-1.0 MPa; Further, Step 1 includes: Step 11: Abrasive Selection: Grind the cast iron grinding disc to a smooth surface beforehand, free of scratches and dents, and apply 800-mesh diamond grinding paste evenly to the surface of the cast iron grinding disc; Step 12: Rough Grinding Operation: Fix the valve seat or valve core to be processed on the grinding fixture, ensuring the workpiece is perpendicular to the grinding disc, start the grinding equipment, set the grinding disc rotation speed to 150 r / min, control the grinding pressure at 0.8-1.0 MPa, and use circumferential grinding method for continuous grinding for 5-8 minutes; Step 13: Rough Grinding Inspection: After rough grinding, remove the machining allowance and surface burrs from the sealing surface to make the sealing surface initially smooth, with the flatness error controlled within 0.005 mm.

[0020] Step 2 Semi-finish grinding: Use 1500-mesh diamond grinding paste, grinder rotation speed 100 r / min, grinding pressure 0.5-0.7 MPa; further, step 2 includes: Step 21 Semi-finish grinding abrasive replacement: Clean the grinding disc, replace with 1500-mesh diamond grinding paste, apply evenly to ensure the abrasive covers the entire working surface of the grinding disc; Step 22 Semi-finish grinding operation: Keep the workpiece clamping position unchanged, adjust the grinding parameters, reduce the grinding disc rotation speed to 100 r / min, adjust the grinding pressure to 0.5-0.7 MPa, continue to use circumferential grinding, grinding time 8-10 minutes; Step 23 Semi-finish grinding inspection: After semi-finish grinding, eliminate the grinding marks left by coarse grinding, further improve the flatness of the sealing surface, control the flatness error within 0.003 mm, and achieve a surface finish of Ra0.1 μm.

[0021] Step 3: Fine grinding treatment: Use 2000-mesh diamond polishing paste, with a polishing disc speed of 60 r / min and a polishing pressure of 0.2-0.3 MPa; further, step 3 includes: Step 31: Abrasive selection for fine grinding: After cleaning the polishing disc, apply a small amount of 2000-mesh diamond polishing paste evenly to avoid scratching the sealing surface due to excessive abrasive; Step 32: Fine grinding operation: Adjust the polishing disc speed to 60 r / min, reduce the polishing pressure to 0.2-0.3 MPa, and use a slow speed and light pressure polishing method for 10-15 minutes. During this period, add a small amount of anhydrous ethanol to the polishing surface every 3 minutes for lubrication and cooling; Step 33: Fine grinding inspection: After fine grinding, the sealing surface should reach the design accuracy, with a flatness error ≤0.001 mm, a surface finish ≥Ra0.05 μm, and no scratches, pits, or missing corners on the sealing surface.

[0022] Through the step-by-step grinding process described above—"rough grinding-semi-fine grinding-fine grinding"—and with the application of diamond grinding paste of different mesh sizes, the sealing surface accuracy of the valve seat and valve core of the miniature proportional valve is gradually improved. The flatness of the sealing surface is ≤0.001mm, and the surface finish is ≥Ra0.05μm. After the valve seat and valve core are fitted together, there are no obvious micro-gaps, effectively reducing the leakage of the miniature proportional valve, which can be controlled to ≤1kPa / 30min (300kPa&H2), avoiding the problem of insufficient accuracy caused by single grinding. Furthermore, the parameters of each step of "rough grinding-semi-fine grinding-fine grinding" are clear and the process is standardized, allowing ordinary workers to quickly get started and reducing the processing difficulty.

[0023] Preferably, the grinding process further includes: Step 4, dedicated cleaning: secondary ultrasonic cleaning, the cleaning solution being anhydrous ethanol and deionized water, and hot air drying at 60-80℃; further, Step 4 includes: Step 41, initial cleaning: placing the ground workpiece in an ultrasonic cleaner, adding anhydrous ethanol as the cleaning solution, setting the ultrasonic power to 200W, and the cleaning time to 10 minutes to remove the grinding paste and metal debris adhering to the surface; Step 42, fine cleaning: removing the workpiece after the initial cleaning, rinsing the surface with deionized water, and then placing it in new anhydrous ethanol for another 5 minutes of ultrasonic cleaning to ensure no abrasive residue remains; Step 43, drying: placing the cleaned workpiece in a hot air drying oven, setting the temperature to 60-80℃, and the drying time to 15 minutes, and then removing it and placing it in a dust-free container for later use to avoid secondary contamination.

[0024] Preferably, the grinding process further includes: Step 5: Finished product inspection: Perform appearance inspection, flatness inspection and surface finish inspection; Further, Step 5 includes: Step 51 Appearance inspection: Observe the sealing surface with a magnifying glass to confirm that there are no appearance defects such as scratches, pits, or abrasive residue; Step 52 Precision inspection: Use a flatness tester to inspect the flatness of the sealing surface and use a surface roughness tester to inspect the surface finish. If both indicators meet the design requirements, the product is qualified. Unqualified products are returned to the grinding process for further processing.

[0025] In summary, after a step-by-step grinding process of "coarse grinding - semi-fine grinding - fine grinding", and with dedicated cleaning and testing steps, abrasive residues are thoroughly removed, defective products are promptly rejected, and subsequent assembly rework is avoided, increasing the product processing qualification rate to over 98%. Furthermore, the entire process can be completed on conventional grinding equipment, with smooth transitions between each step, meeting the production needs of batch processing of miniature proportional valves and reducing manufacturing costs.

[0026] The following describes embodiments of this application. This embodiment focuses on grinding the valve seat sealing surface of a miniature proportional valve for gas chromatographs. The valve seat material is 304 stainless steel, the sealing surface diameter is 8mm, and the design requirements are: flatness ≤0.001mm and surface finish ≥Ra0.05μm.

[0027] 1. Rough grinding: Apply 800-mesh diamond grinding paste to the cast iron grinding disc, fix the valve seat on the grinding fixture, set the grinding disc speed to 150 r / min, the grinding pressure to 0.9 MPa, and grind the circumference for 6 minutes. After rough grinding, the flatness of the sealing surface is 0.004 mm. Remove surface burrs and machining allowance. 2. Semi-fine grinding treatment: After cleaning the grinding disc, replace with 1500-mesh diamond grinding paste, adjust the speed to 100 r / min, the pressure to 0.6 MPa, and grind for 9 minutes. After semi-fine grinding, the flatness of the sealing surface is 0.002 mm, the surface finish Ra is 0.08 μm, and the rough grinding marks are eliminated. 3. Fine grinding treatment: After cleaning the grinding disc, apply 2000-grit diamond grinding paste, adjust the speed to 60 r / min, the pressure to 0.25 MPa, and grind for 12 minutes. During the process, add anhydrous ethanol every 3 minutes. After fine grinding, the sealing surface is free of scratches and pits. 4. Special cleaning: Place the valve seat in an ultrasonic cleaner, ultrasonically clean it for 10 minutes in anhydrous ethanol at 200W, rinse it with deionized water, ultrasonically clean it again for 5 minutes, and then put it in an 80℃ hot air drying oven to dry for 15 minutes. 5. Finished product inspection: The sealing surface was observed to have no visible defects using a magnifying glass. The flatness was measured to be 0.0008 mm by a flatness tester, and the surface finish was measured to be Ra 0.04 μm by a surface roughness tester. Both indicators meet the design requirements, and the product is qualified.

[0028] The machined valve seat was assembled with the matching valve core, and a sealing performance test was conducted. Under the condition of 300 kPa & H2, the leakage was 0.7 kPa / 30 min, which showed excellent sealing performance and met the requirements for use of miniature proportional valves for gas chromatographs.

[0029] The key technical points of this application are: 1. Adopt a step-by-step grinding method of "coarse grinding - semi-fine grinding - fine grinding" and use diamond grinding paste of different mesh sizes to gradually improve the precision of the sealing surface and avoid the problem of insufficient precision caused by single grinding. 2. Design exclusive speed and pressure parameters for each grinding process, and use a slow speed and light pressure fine grinding method to effectively ensure the smoothness of the sealing surface and prevent scratches; 3. After grinding, a dedicated secondary ultrasonic cleaning + hot air drying step is set up to thoroughly remove abrasive residue and avoid wear on the sealing surface after subsequent assembly; 4. The process steps are standardized and the parameters are clear. It does not rely on workers' experience. Ordinary operators can operate it after simple training, which is suitable for mass production.

[0030] The implementation of this application will yield the following beneficial effects: 1. Significantly improved sealing accuracy: Through stepped grinding and precise parameter control, the flatness of the sealing surface is ≤0.001mm, the smoothness is ≥Ra0.05μm, and there are no obvious micro gaps after the valve seat and valve core are fitted together, which effectively reduces the leakage of the micro proportional valve and can be controlled at ≤1kPa / 30min (300kPa&H2). 2. Easy-to-operate processing technology: The parameters of each step are clear and the process is standardized, eliminating the reliance on workers' experience in traditional manual grinding. Ordinary people can quickly get started, reducing the processing difficulty. 3. High product qualification rate: After grinding, there are dedicated cleaning and testing steps to thoroughly remove abrasive residue, promptly reject unqualified products, avoid subsequent assembly rework, and increase the product processing qualification rate to over 98%. 4. Suitable for mass production: The entire process can be completed on conventional grinding equipment without the need for additional complex equipment. The steps are seamlessly connected, which can meet the production needs of mass processing of miniature proportional valves and reduce manufacturing costs. 5. Extend valve service life: The sealing surface has a high degree of smoothness and no defects, resulting in less wear after mating, which effectively extends the overall service life of the miniature proportional valve and improves product reliability.

[0031] It should be noted that in the description of the embodiments of this application, the terms "front," "rear," "left," "right," "up," "down," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0032] In summary, due to the adoption of the above technical features, the present invention has the following advantages and positive effects compared with the prior art: First, this application significantly improves sealing accuracy through stepped grinding and precise parameter control; Secondly, the parameters for each step in this application are clear and the process is standardized, allowing staff to get started quickly and reducing processing difficulty. Third, the unique cleaning and testing steps in this application thoroughly remove abrasive residues, improving the product processing qualification rate.

[0033] The preferred embodiments of the invention are merely illustrative of the invention. They do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. These embodiments have been selected and specifically described in this specification to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to make good use of the invention. The invention is limited only by the claims and their full scope and equivalents. The above disclosures are merely preferred embodiments of the invention, but are not intended to limit it. Any equivalent changes and modifications made by those skilled in the art without departing from the spirit and essence of the invention should fall within the protection scope of the invention.

Claims

1. A proportional valve grinding process, characterized in that, The grinding process is used for machining the hard metal sealing surfaces of the valve seat and valve core of a miniature proportional valve. The grinding process includes: Step 1: Coarse grinding: Use 800-mesh diamond grinding paste, grinder rotation speed 150 r / min, grinding pressure 0.8-1.0 MPa; Step 2 Semi-finish grinding: Use 1500-mesh diamond grinding paste, grinder rotation speed 100 r / min, grinding pressure 0.5-0.7 MPa; Step 3: Fine grinding: Use 2000-mesh diamond grinding paste, grinder rotation speed 60r / min, grinding pressure 0.2-0.3MPa.

2. The proportional valve grinding process as described in claim 1, characterized in that, The grinding process also includes: Step 4 Special cleaning: Secondary ultrasonic cleaning, the cleaning solution is anhydrous ethanol and deionized water, and hot air drying at 60-80℃.

3. The proportional valve grinding process as described in claim 2, characterized in that, The grinding process also includes: Step 5 Finished product inspection: performing appearance inspection, flatness inspection and surface finish inspection.

4. The proportional valve grinding process as described in claim 1, characterized in that, Step 1 includes: Step 11 Abrasive selection: The cast iron grinding disc is pre-polished to a smooth surface, free of scratches and dents. Apply 800-grit diamond grinding paste evenly to the surface of the cast iron grinding disc. Step 12: Rough grinding operation: Fix the valve seat or valve core to be processed on the grinding fixture, ensuring that the workpiece is perpendicular to the grinding disc, start the grinding equipment, set the grinding disc speed to 150 r / min, control the grinding pressure at 0.8-1.0 MPa, use the circumferential grinding method, and continue grinding for 5-8 minutes. Step 13: Rough grinding inspection: After rough grinding, remove the machining allowance and surface burrs from the sealing surface to make the sealing surface initially flat, and control the flatness error within 0.005mm.

5. The proportional valve grinding process as described in claim 1, characterized in that, Step 2 includes: Step 21 Semi-finish grinding abrasive replacement: Clean the grinding disc and replace it with 1500-grit diamond grinding paste. Apply it evenly to ensure that the abrasive covers the entire working surface of the grinding disc. Step 22 Semi-fine grinding operation: Keep the workpiece clamping position unchanged, adjust the grinding parameters, reduce the grinding disc speed to 100 r / min, adjust the grinding pressure to 0.5-0.7 MPa, continue to use the circumferential grinding method, and grind for 8-10 minutes; Step 23 Semi-fine grinding inspection: After semi-fine grinding, the grinding marks left by coarse grinding are eliminated, and the flatness of the sealing surface is further improved. The flatness error is controlled within 0.003mm, and the surface finish reaches Ra0.1μm.

6. The proportional valve grinding process as described in claim 1, characterized in that, Step 3 includes: Step 31: Selection of abrasive for fine grinding: After cleaning the grinding disc, apply a small amount of 2000-grit diamond grinding paste evenly to avoid scratching the sealing surface due to excessive abrasive. Step 32 Fine grinding operation: Adjust the grinding disc speed to 60r / min, reduce the grinding pressure to 0.2-0.3MPa, adopt a slow speed and light pressure grinding method, and grind for 10-15 minutes. During this period, add a small amount of anhydrous ethanol to the grinding surface every 3 minutes to lubricate and cool it down. Step 33 Fine grinding inspection: After fine grinding, the sealing surface reaches the design accuracy, with a flatness error ≤0.001mm, a surface finish ≥Ra0.05μm, and no scratches, pits, or missing corners on the sealing surface.

7. The proportional valve grinding process as described in claim 2, characterized in that, Step 4 includes: Step 41 Initial cleaning: Place the ground workpiece into an ultrasonic cleaner, add anhydrous ethanol as the cleaning solution, set the ultrasonic power to 200W, and the cleaning time to 10 minutes to remove the grinding paste and metal shavings adhering to the surface. Step 42 Fine cleaning: Take out the workpiece after the initial cleaning, rinse the surface with deionized water, and then put it into new anhydrous ethanol for ultrasonic cleaning again for 5 minutes to ensure that there is no abrasive residue. Step 43 Drying: Place the cleaned workpiece into a hot air drying oven, set the temperature to 60-80℃, and dry for 15 minutes. After drying, remove it and place it in a dust-free container for later use to avoid secondary contamination.

8. The proportional valve grinding process as described in claim 3, characterized in that, Step 5 includes: Step 51: Visual inspection: Use a magnifying glass to observe the sealing surface and confirm that there are no scratches, pits, abrasive residues or other visual defects. Step 52 Precision Inspection: The flatness of the sealing surface is checked using a flatness tester, and the smoothness is checked using a surface roughness tester. If both indicators meet the design requirements, the product is considered qualified. Unqualified products are returned to the grinding process for further processing.

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