A method for processing 3D surface tool marks of metal appearance pieces

Abstract

The application provides a method for processing 3D surface knife marks of metal appearance pieces, comprising the following steps: S1, model design; S2, processing and forming: S2.1, using a turning process, a polymer grinding head is processed according to a designed polymer grinding head model by using a CNC machine tool; S2.2, heat treatment: the grinding wheel of the polymer grinding head is subjected to heat treatment; S3, assembly; S4, making a 3D concave surface: the PCD planer is fixed on the tool holder, a 3D concave surface program is executed, the grinding wheel is trimmed in a 3D contour by using the PCD planer, and a 3D concave polymer grinding head is obtained; S5, shock repair; S6, repairing the 3D concave surface; and S7, circulation. By using the specially designed 3D concave polymer grinding head to shock and polish, the application can more accurately and uniformly repair the knife marks on the metal appearance pieces, so that the surface quality after repair is significantly improved. This method repairs the specific form of the knife marks, and reduces the problem that traces can still be seen after repair.

Description

Technical Field

[0001] This invention belongs to the field of polishing technology, and in particular, it is a method for treating the tool marks on the 3D surface of metal exterior parts. Background Technology

[0002] In modern manufacturing, especially in the production of 3C products, the precision machining quality of metal exterior parts directly impacts the market performance of the final product. Milling is a commonly used metal processing technique for creating complex 3D surfaces. However, during milling, resonance of the machinery, vibration of the external environment, and instability of cutting parameters (such as variations in cutting forces at corners) often leave undesirable linear marks on the metal exterior parts. These marks not only affect the appearance quality of the product but may also reduce its structural integrity.

[0003] The conventional approach to handling such problems currently involves secondary milling repair, provided the dimensions are compliant. However, this method has certain limitations: First, in most cases, milling can only provide one effective repair; more than one repair can lead to changes in material properties, thus affecting product performance. Second, even after secondary milling, a certain percentage of products will still be defective, which undoubtedly increases production costs and material waste.

[0004] Therefore, there is an urgent need to develop a more effective method for processing tool marks on 3D surfaces of metal exterior parts in order to improve repair quality and reduce scrap rates.

[0005] For example, Chinese patent literature has disclosed a 3D watch cover processing method [Chinese Patent No.: 202210739875.8]. This invention discloses a 3D watch cover processing method, including processes such as cutting, CNC engraving, polishing, and tempering. Specifically, the raw material is first cut to obtain a watch cover slice to be processed; then, the shape, bottom edge, and top surface of the watch cover are ground using a CNC engraving machine; next, a polishing machine is used to lightly polish the 3D curved surface; finally, the polished watch cover is tempered to obtain the corresponding finished 3D watch cover. This invention uses a CNC engraving machine combined with tooling vacuum adsorption for 3D cold processing of the glass surface and polishing of the frosted surface, simultaneously achieving a dual improvement in production quality and efficiency, ensuring the product's forming effect and various performance parameters, and saving a significant amount of financial and material resources.

[0006] Although the above technical solution discloses the 3D polishing process, it is limited to the processing technology of 3D watch covers and lacks disclosure of the specific materials and manufacturing process of the polishing head. Its processing method for 3D watch covers is also limited to a certain extent and still needs further optimization. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a method for processing tool marks on the 3D surfaces of metal exterior parts.

[0008] The objective of this invention can be achieved through the following technical solution: a method for processing tool marks on the 3D surface of a metal exterior component, the method comprising the following steps:

[0009] S1 Model Design: The polymer grinding head model is designed using design software. The polymer grinding head includes a tool holder, with a grinding wheel fixedly connected to the end of the tool holder. The grinding wheel is a cylinder with a central hole on one end face. The tool holder is a round shaft, which passes through the central hole of the cylinder to form a fixed connection. The round shaft and the cylinder are coaxially arranged.

[0010] S2 Machining: S2.1 adopts turning process and uses CNC machine tool to process polymer grinding head according to the designed polymer grinding head model; during the polymer grinding head forming process, the tool holder is embedded in the grinding wheel to a depth of 15-20mm, the tool holder is knurled, the knurling depth is greater than 1mm, and the length of the knurling exposed on the grinding wheel does not exceed 5mm.

[0011] The tool holder is embedded in the grinding wheel to a depth of 15-20mm: This depth range is chosen to ensure sufficient contact area and engagement depth between the tool holder and the grinding wheel, thereby providing sufficient structural strength and stability. This design can reduce the vibration and offset of the tool holder during high-speed rotation and grinding, and improve the machining accuracy and safety.

[0012] The tool holder is knurled to a depth greater than 1mm: Knurling increases the friction on the tool holder surface, helping to more firmly secure the connection between the tool holder and the grinding wheel. A knurling depth greater than 1mm ensures that the tool holder surface has sufficient texture, enhancing clamping force and preventing slippage during high-load or high-speed operation.

[0013] The knurling protrusion from the grinding wheel should not exceed 5mm: This design limitation ensures that most of the knurled area of ​​the tool holder is embedded in the grinding wheel, with only a small portion exposed. This helps protect the knurled part from direct wear, while also providing enough exposure for secure gripping by machine tool fixtures, balancing durability and functionality.

[0014] S2.2 Heat treatment: The grinding wheel of the polymer grinding head is heat treated at a temperature of 100℃-150℃ for 2-4 hours.

[0015] The purpose of heat treatment is to improve the mechanical strength and wear resistance of the grinding wheel. The heat treatment temperature of 100℃-150℃ is chosen because this temperature range can effectively promote the cross-linking reaction of the prepolymer in polyurethane, enhance the cohesive force of the material without causing polymer decomposition or excessive hardening. This temperature range can ensure that the polyurethane grinding wheel maintains good physical properties and stable chemical structure during processing and use.

[0016] The heat treatment time of 2-4 hours is based on the sufficient reaction time required for complete cross-linking of the polyurethane material. Too short a time may lead to incomplete cross-linking, affecting the durability of the grinding wheel and the repair effect; while too long a time may lead to unnecessary degradation of the material properties. Therefore, the heat treatment time of 2-4 hours was determined experimentally to achieve the optimal balance of physical and chemical properties.

[0017] S3 Assembly: The polymer grinding head is assembled onto the CNC machine tool by clamping the tool holder of the polymer grinding head with the clamping components of the CNC machine tool.

[0018] S4 3D concave surface creation: Fix the PCD planer on the tool holder, execute the 3D concave surface creation program, use the PCD planer to perform 3D contour dressing on the grinding wheel, and obtain a 3D concave surface polymer grinding head;

[0019] The outer circumferential surface of the grinding wheel of the 3D concave polymer grinding head is provided with an annular 3D concave surface. The 3D concave surface includes the bottom surface of the annular groove, and the two sides of the bottom surface of the annular groove are connected to the outer circumferential surface of the grinding wheel by rounded chamfers.

[0020] The specific steps for creating a 3D concave surface are as follows:

[0021] 1. Set CNC machine parameters: Load the 3D concave surface creation program onto the CNC machine.

[0022] Set the cutting speed, feed rate, and depth of cut;

[0023] 2. Fixing and aligning the PCD polishing tool: Fix the PCD polishing tool on the self-made tool holder, ensuring that the fixed position of the tool is completely aligned with the preset machining path;

[0024] Use the calibration function of the CNC machine tool to ensure that the initial position of the tool is correct and the alignment accuracy is high.

[0025] 3. Execution: Start the CNC machine tool and cut according to the program instructions. The PCD planer moves precisely along the predetermined 3D contour path to gradually form the required 3D concave surface.

[0026] The 3D concave design allows the grinding wheel to better adapt to the complex geometry of the metal parts being machined. The annular 3D concave surface provides a wider contact area, enhancing the grinding wheel's adaptability to metal surfaces and grinding efficiency. This design aims to improve machining quality, reduce the number of times the grinding wheel needs to be dressed or replaced, thereby increasing production efficiency and reducing costs.

[0027] S5 Oscillation Repair: By executing the 3D spline path program, the 3D concave polymer grinding head oscillates up and down on the 3D spline. Utilizing the 3D concave surface of the grinding wheel, the 3D surface of the metal surface is repaired by repeatedly oscillating and grinding the tool marks on the metal surface.

[0028] Grinding is performed by oscillating up and down along a 3D spline. To achieve higher repair accuracy and adapt to complex 3D concave surface shapes, this grinding method ensures that the 3D concave surface of the grinding wheel and the cutting edges of the metal surface part make uniform contact and act in multiple directions, resulting in more uniform material removal and surface smoothing. Furthermore, the 3D spline path can be optimized according to the specific geometric features of the part being repaired, making the movement of the grinding head on complex curved surfaces more flexible and efficient, effectively avoiding over-grinding and un-grinded areas, thereby improving repair quality and work efficiency. This method allows for fine-tuning of specific 3D cutting edge features, ensuring that surface defects are effectively eliminated while maintaining the structural strength of the metal surface part. S6 Repairing 3D Concave Surfaces: After repairing several metal surface parts, a 3D concave surface polymer grinding head repair program is executed, using a PCD polishing tool to repair the 3D concave surface of the 3D concave surface polymer grinding head.

[0029] Specific steps for oscillation repair using a 3D spline path program;

[0030] 1. Path design: Use design software to design 3D spline paths. The 3D spline path is determined based on the specific contour of the 3D surface of the metal surface to be repaired and the depth of the tool marks. When designing the path, it is necessary to ensure that the 3D concave surface of the polymer grinding head can uniformly and fully contact all tool mark areas to achieve effective oscillating grinding.

[0031] 2. Perform oscillatory grinding: On the CNC machine tool, according to the loaded 3D spline path program, the 3D concave polymer grinding head is controlled to swing up and down along the predetermined path on the 3D tool mark surface of the metal appearance part to perform oscillatory grinding; during the oscillatory grinding process, the 3D concave surface of the 3D polymer grinding head continuously contacts the metal appearance part, and the tool marks are gradually removed from multiple directions by utilizing the annular 3D concave shape, so that the surface tends to be smooth.

[0032] S6 Repair 3D Concave Surface: After repairing a number of metal exterior parts, execute the 3D concave surface repair program and use the PCD polishing tool to repair the 3D concave surface of the 3D concave surface polymer grinding head.

[0033] The steps and settings to be followed when repairing a 3D concave polymer grinding head using a 3D concave repair program are as follows;

[0034] 1. Inspection and Monitoring: The 3D concave surface repair program automatically checks the tool compensation parameters of the PCD polishing tool to verify whether the tool compensation parameters have changed since the last repair. If there are any unauthorized modifications, an alarm will be issued and the operation will be paused, waiting for operator confirmation or the correct parameters to be reset.

[0035] 2. Set repair rules: Record the number of metal surface parts repaired by the 3D concave polymer grinding head, set a threshold for the number of metal surface parts repaired, and trigger the 3D concave repair operation on the 3D concave polymer grinding head when the number of metal surface parts repaired reaches the threshold.

[0036] Set the amount of 3D concave surface repaired on the 3D concave polymer grinding head each time;

[0037] Record the number of times the 3D concave surface of the polymer grinding head is repaired;

[0038] Set the minimum diameter of the 3D concave surface of the 3D concave polymer grinding head; when the diameter of the 3D concave surface of the 3D concave polymer grinding head reaches or falls below the minimum diameter, stop the 3D concave surface repair operation.

[0039] After each repair of the 3D concave surface of the 3D concave polymer grinding head, the repair coordinates are automatically updated.

[0040] S7 loop: Repeat steps S5-S6 to achieve continuous operation.

[0041] A method for processing 3D surface grooves on metal parts, characterized in that, in step S2, the material used to make the tool holder is 7075 aluminum rod or S45C rod; and the material used to make the grinding wheel is polyurethane block.

[0042] Reasons for using 7075 aluminum rods: High strength and lightweight characteristics: 7075 aluminum alloy is a high-strength material. When making tool holders for polymer grinding heads, 7075 aluminum rods can provide sufficient strength to withstand the high stress generated during grinding. At the same time, due to its low density, it can effectively reduce the overall weight, improve operational flexibility and efficiency; Good fatigue resistance: This type of material has excellent fatigue resistance, making it suitable for frequent or long-term high-speed rotation and machining, which helps to improve the service life and reliability of tools.

[0043] Reasons for using S45C bars: Good machinability: S45C is a medium carbon steel with good machinability and heat treatment properties, making it suitable for manufacturing tools that require high strength and wear resistance; Cost-effectiveness: Compared with some high-grade alloys, S45C is less expensive, but provides sufficient performance to meet the requirements of grinding head holders, making the entire production process more economical.

[0044] By manufacturing polyurethane blocks, the chemical composition and physical properties of the polymer, such as hardness, abrasion resistance, and impact resistance, can be precisely controlled to meet polishing requirements and extend service life.

[0045] The polyurethane block is a self-made polyurethane block. The specific steps for making the self-made polyurethane block are as follows:

[0046] A1. Raw material preparation: The raw materials are polyols and isocyanates, with a weight ratio of 1:0.9 to 1:1.1.

[0047] A2 Mixing: The polyol and isocyanate are mixed evenly at 23℃-28℃ to obtain the initial mixture.

[0048] A3 Adding abrasive: Mix the initial mixture with the abrasive at a weight ratio of 10:1-10:3 to obtain a reaction mixture. The abrasive is selected from alumina and silicon carbide.

[0049] A4 Preheating: Preheat the reaction mixture to 45℃-55℃;

[0050] A5 Molding: The preheated reaction mixture is reacted in a reactor at 65℃-75℃ for 1-2 hours to form a polyurethane block.

[0051] Preferably, in step S4, the tool holder includes a base plate with a fixed area, which is a strip groove formed on the base plate. Bolts pass through the strip groove, and the overall tool holder can be adjusted and installed on the equipment by relative displacement of the bolts within the strip groove.

[0052] A support plate is erected on the base plate, and a U-shaped plate is fixed to the top of the support plate. The open end of the U-shaped plate has a notch for assembling a PCD planer. The open end of the U-shaped plate has two end faces, and the notch penetrates either of the end faces in a horizontal direction. Several threaded holes are opened on the U-shaped plate, and screws are inserted into the threaded holes. The base plate is arranged horizontally, the support plate is arranged vertically, and the U-shaped plate is arranged horizontally. The base plate, the support plate, and the U-shaped plate form a Z-shaped structure that is vertically connected in sequence.

[0053] The tool holder design includes a base plate, a support plate, and a U-shaped plate. The main reasons for choosing this structure are as follows:

[0054] 1. Stability and strength: Lateral arrangement of the base plate: The lateral arrangement of the base plate provides a stable foundation for the entire tool holder, enabling the tool holder to withstand pressure and vibration from different directions during processing and maintain processing accuracy;

[0055] Vertical setting of the support plate: The vertical support plate improves the vertical strength of the tool holder, helps to reduce swaying or bending in the vertical direction, and ensures the precise alignment of the tool during the machining process;

[0056] 2. Functionality and Adjustability: U-shaped plate design: The U-shaped plate has notches specifically for mounting and securing the PCD planer. This design allows for quick tool changes to adapt to different machining needs, while ensuring tool stability during machining.

[0057] Applications of threaded holes and screws: The threaded holes allow for fine-tuning of the tool mounting position on the U-shaped plate, thereby optimizing machining accuracy. By adjusting the screws, the specific position and angle of the tool can be changed to meet the needs of complex machining contours.

[0058] 3. Durability and Maintenance: Material Selection and Structural Design: The selected materials and structural design take into account the wear and aging issues that may occur during long-term use. The vertical connection design of the structure simplifies the replacement and maintenance of each part, so that the tool holder can maintain the integrity of the structure and the stability of its function even after long-term high-load operation.

[0059] 4. Advantages of Z-shaped structure: Space utilization and ease of operation: The Z-shaped structure design helps to make efficient use of space, making it easier for operators to change and adjust tools. In addition, this design also helps to improve visibility during the machining process, allowing operators to observe the machining status more clearly and make real-time adjustments.

[0060] This comprehensive design of the tool holder not only improves processing efficiency and precision, but also enhances the adaptability and ease of operation of the equipment, meeting the demand for efficient and high-quality processing in industrial production.

[0061] 5. A method for treating tool marks on the 3D surface of a metal exterior part, characterized in that, in step S5, when the 3D concave surface of a grinding wheel is used to repair the tool marks on the 3D surface of the metal exterior part, the amount of material removed in a single repair is 0.02 mm, wherein the amount of material removed by the 3D concave surface of the grinding wheel in a single direction each time it contacts the tool marks on the 3D surface of the metal exterior part is 0.01 mm.

[0062] The number of times the 3D concave surface of the grinding wheel is used to repeatedly vibrate and polish the 3D surface of the metal exterior part should not exceed 5.

[0063] The material removal amount of 0.01 mm in one direction is based on the fine adjustment of the surface of the metal appearance part and the minimization of material removal to avoid excessive wear and damage. This precise control helps to maintain the structural integrity and surface quality of the metal part.

[0064] The limit of no more than 5 times is to prevent unnecessary thermal stress and physical damage to the metal surface, which may accumulate during repeated wear. Too many polishing times may cause microstructural deformation or fatigue of the metal surface, affecting its long-term reliability and performance. By limiting the maximum number of times, the degree of wear can be effectively controlled and the mechanical properties of the metal surface can be protected.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] 1. Improved Repair Quality: By using a specially designed 3D concave polymer grinding head for oscillating grinding, this invention can more accurately and evenly repair tool marks on metal exterior parts, thereby significantly improving the surface quality after repair. This method repairs the specific shape of the tool marks, reducing the problem of visible traces after repair.

[0067] 2. Reduce scrap rate: The repair method proposed in this invention can effectively repair the tool marks on metal parts multiple times without damaging the properties of the material itself, thereby reducing the scrap rate. This is a significant improvement for production costs and resource utilization.

[0068] 3. Sustainable use and maintenance: The design allows for the restoration of its performance through a repair procedure after a certain period of use, which not only extends the service life of the grinding head, but also reduces the frequency of tool replacement and related costs;

[0069] 4. Innovation in materials and processes: By using self-made polyurethane blocks and specific heat treatment processes, this invention enhances the durability and efficiency of the grinding head material, ensuring the stability and repeatability of the overall repair process. Attached Figure Description

[0070] Figure 1 This is a three-dimensional structural diagram of the polymer grinding head in this invention.

[0071] Figure 2 This is a front view structural diagram of the tool holder in this invention.

[0072] Figure 3 This is a top view of the tool holder in this invention.

[0073] Figure 4 This is a side view of the tool holder in this invention.

[0074] In the diagram, 1 is the tool holder; 2 is the grinding wheel; 2a is the 3D concave surface; 3 is the base plate; 3a is the strip groove; 4 is the support plate; 5 is the U-shaped plate; 5a is the notch; and 6 is the screw. Detailed Implementation

[0075] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0076] A method for processing tool marks on the 3D surface of a metal exterior part, comprising the following steps:

[0077] like Figure 1 As shown, S1 model design: The polymer grinding head model is designed using design software; the polymer grinding head includes a tool holder 1, and a grinding wheel 2 is fixedly connected to the end of the tool holder 1. The grinding wheel 2 is a cylinder with a central hole on one end face. The tool holder 1 is a round shaft, which passes through the central hole of the cylinder to form a fixed connection. The round shaft and the cylinder are coaxially arranged.

[0078] S2 Machining: S2.1 adopts turning process and uses CNC machine tool to process polymer grinding head according to the designed polymer grinding head model; during the polymer grinding head forming process, the tool holder 1 is embedded in the grinding wheel 2 to a depth of 15-20mm, the tool holder 1 is knurled, the knurling depth is greater than 1mm, and the length of the knurling exposed on the grinding wheel 2 does not exceed 5mm.

[0079] The material used to make the tool holder 1 is either 7075 aluminum rod or S45C rod; the material used to make the grinding wheel 2 is polyurethane block.

[0080] The specific steps for making your own polyurethane block are as follows:

[0081] A1. Raw material preparation: The raw materials are polyol and isocyanate, with a weight ratio of 1:0.9-1:1.1; the polyol is either polyether polyol or polyester polyol, and the isocyanate is either toluene diisocyanate or diphenylmethane diisocyanate.

[0082] A2 Mixing: The polyol and isocyanate are mixed evenly at 23℃-28℃ to obtain the initial mixture.

[0083] A3 Adding abrasive: Mix the initial mixture with the abrasive at a weight ratio of 10:1-10:3 to obtain a reaction mixture. The abrasive may be either alumina or silicon carbide.

[0084] A4 Preheating: Preheat the reaction mixture to 45℃-55℃;

[0085] A5 Molding: The preheated reaction mixture is reacted in a reactor at 65℃-75℃ for 1-2 hours to form a polyurethane block.

[0086] S2.2 Heat treatment: The grinding wheel 2 of the polymer grinding head is heat treated at a temperature of 100℃-150℃ for 2-4 hours.

[0087] S3 Assembly: The polymer grinding head is assembled onto the CNC machine tool by clamping the tool holder 1 of the polymer grinding head with the clamping components of the CNC machine tool.

[0088] S4 Create 3D concave surface 2a: Fix the PCD planer on the tool holder, execute the 3D concave surface creation program, use the PCD planer to perform 3D contour trimming on the grinding wheel 2, and obtain a 3D concave surface polymer grinding head;

[0089] like Figures 2 to 4 As shown, the tool holder includes a base plate 3 with a fixed area, which is a strip groove 3a formed on the base plate 3. Bolts pass through the strip groove 3a, and the tool holder can be adjusted and installed on the equipment by relative displacement of the bolts within the strip groove 3a. A support plate 4 is erected on the base plate 3, and a U-shaped plate 5 is fixed to the top of the support plate 4. The open end of the U-shaped plate 5 has a notch 5a for assembling the PCD planer. The open end of the U-shaped plate 5 has two end faces, and the notch 5a penetrates either end face in a horizontal direction. Several threaded holes are formed on the U-shaped plate 5, and screws 6 pass through the threaded holes. The base plate 3 is arranged horizontally, the support plate 4 is arranged vertically, and the U-shaped plate 5 is arranged horizontally. The base plate 3, the support plate 4, and the U-shaped plate 5 form a Z-shaped structure that is vertically connected in sequence.

[0090] like Figure 1 As shown, the outer peripheral surface of the grinding wheel 2 of the 3D concave polymer grinding head is provided with an annular 3D concave surface 2a. The 3D concave surface 2a includes an annular groove bottom surface, and the two sides of the annular groove bottom surface are connected to the outer peripheral surface of the grinding wheel 2 by rounded chamfers.

[0091] The specific steps for creating the 3D concave surface 2a are as follows:

[0092] 1. Set CNC machine parameters: Load the 3D concave surface creation program onto the CNC machine.

[0093] Set the cutting speed, feed rate, and depth of cut;

[0094] 2. Fixing and aligning the PCD polishing tool: Fix the PCD polishing tool on the self-made tool holder, ensuring that the fixed position of the tool is completely aligned with the preset machining path;

[0095] Use the calibration function of the CNC machine tool to ensure that the initial position of the tool is correct and the alignment accuracy is high.

[0096] 3. Execution: Start the CNC machine tool and cut according to the program instructions. The PCD tool moves precisely along the predetermined 3D contour path to gradually form the required 3D concave surface 2a.

[0097] S5 Oscillation Repair: By executing the 3D spline path program, the 3D concave polymer grinding head oscillates up and down on the 3D spline. Using the 3D concave surface 2a of the grinding wheel 2, the tool marks on the 3D surface of the metal appearance part are repaired by repeatedly oscillating and grinding the tool marks on the 3D surface of the metal appearance part.

[0098] When using the 3D concave surface 2a of the grinding wheel 2 to repair the tool marks on the 3D surface of the metal exterior part, the repair amount per single repair is 0.02mm. In this case, the amount of material removed by the 3D concave surface 2a of the grinding wheel 2 in a single direction each time it contacts the tool marks on the 3D surface of the metal exterior part is 0.01mm.

[0099] The number of times the 3D concave surface 2a of the grinding wheel 2 is used to repeatedly vibrate and grind the 3D surface of the metal appearance part is no more than 5 times.

[0100] Specific steps for oscillation repair using a 3D spline path program;

[0101] 1. Path design: Use design software to design 3D spline path. The 3D spline path is determined according to the specific contour of the 3D surface of the metal surface to be repaired and the depth of the tool marks. When designing the path, it is necessary to ensure that the 3D concave surface 2a of the polymer grinding head can uniformly and fully contact all tool mark areas to achieve effective oscillating grinding.

[0102] 2. Perform oscillatory grinding: On the CNC machine tool, according to the loaded 3D spline path program, the 3D concave polymer grinding head is controlled to swing up and down along the predetermined path on the 3D tool mark surface of the metal appearance part to perform oscillatory grinding; during the oscillatory grinding process, the 3D concave surface 2a of the 3D concave polymer grinding head continuously contacts the metal appearance part, and the tool marks are gradually removed from multiple directions by utilizing the annular 3D concave shape, so that the surface tends to be smooth.

[0103] S6 Repair 3D Concave Surface 2a: After repairing a number of metal exterior parts, execute the 3D concave surface repair program and use the PCD polishing tool to repair the 3D concave surface 2a of the 3D concave surface polymer grinding head.

[0104] The steps and settings to be followed when repairing a 3D concave polymer grinding head using a 3D concave repair program are as follows;

[0105] 1. Inspection and Monitoring: The 3D concave surface repair program automatically checks the tool compensation parameters of the PCD polishing tool to verify whether the tool compensation parameters have changed since the last repair. If there are any unauthorized modifications, an alarm will be issued and the operation will be paused, waiting for operator confirmation or the correct parameters to be reset.

[0106] 2. Set repair rules: Record the number of metal appearance parts repaired by the 3D concave polymer grinding head, set a threshold for the number of metal appearance parts repaired, and trigger the 3D concave 2a repair operation on the 3D concave polymer grinding head when the number of metal appearance parts repaired reaches the threshold.

[0107] Set the amount of 3D concave surface repaired on the 3D concave polymer grinding head each time;

[0108] Record the number of times the 3D concave surface of the polymer grinding head is repaired;

[0109] Set the minimum diameter of the 3D concave surface 2a of the 3D concave polymer grinding head; when the diameter of the 3D concave surface 2a of the 3D concave polymer grinding head reaches or falls below the minimum diameter, stop the 3D concave surface repair operation.

[0110] After each repair of the 3D concave surface 2a of the 3D concave polymer grinding head, the repair coordinates are automatically updated.

[0111] S7 loop: Repeat steps S5-S6 to achieve continuous operation.

[0112] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0113] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A method for processing 3D surface tool marks on metal exterior parts, characterized in that, The method for processing 3D surface grooves on metal exterior parts includes the following steps: S1 Model Design: The polymer grinding head model is designed using design software. The polymer grinding head includes a tool holder, with a grinding wheel fixedly connected to the end of the tool holder. The grinding wheel is a cylinder with a central hole on one end face. The tool holder is a round shaft, which passes through the central hole of the cylinder to form a fixed connection. The round shaft and the cylinder are coaxially arranged. S2 Machining: S2.1 adopts turning process and uses CNC machine tool to process polymer grinding head according to the designed polymer grinding head model; during the polymer grinding head forming process, the tool holder is embedded in the grinding wheel to a depth of 15-20mm, the tool holder is knurled, the knurling depth is greater than 1mm, and the length of the knurling exposed on the grinding wheel does not exceed 5mm. S2.2 Heat treatment: The grinding wheel of the polymer grinding head is heat treated at a temperature of 100℃-150℃ for 2-4 hours. In step S2, the material used to make the tool holder is 7075 aluminum rod or S45C rod; the material used to make the grinding wheel is polyurethane block, which is a self-made polyurethane block. The specific steps for making your own polyurethane block are as follows: A1. Raw material preparation: The raw materials are polyols and isocyanates, with a weight ratio of 1:0.9 to 1:1.

1. A2 Mixing: The polyol and isocyanate are mixed evenly at 23℃-28℃ to obtain the initial mixture. A3 Adding abrasive: Mix the initial mixture with the abrasive at a weight ratio of 10:1-10:3 to obtain a reaction mixture. The abrasive may be either alumina or silicon carbide. A4 Preheating: Preheat the reaction mixture to 45℃-55℃; A5 molding: The preheated reaction mixture is reacted in a reactor at 65℃-75℃ for 1-2 hours to form a polyurethane block; S3 Assembly: The polymer grinding head is assembled onto the CNC machine tool by clamping the tool holder of the polymer grinding head with the clamping components of the CNC machine tool. S4 3D concave surface creation: Fix the PCD planer on the tool holder, execute the 3D concave surface creation program, use the PCD planer to perform 3D contour dressing on the grinding wheel, and obtain a 3D concave surface polymer grinding head; The outer circumferential surface of the grinding wheel of the 3D concave polymer grinding head is provided with an annular 3D concave surface. The 3D concave surface includes the bottom surface of the annular groove, and the two sides of the bottom surface of the annular groove are connected to the outer circumferential surface of the grinding wheel by rounded chamfers. S5 Oscillation Repair: By executing the 3D spline path program, the 3D concave polymer grinding head oscillates up and down on the 3D spline. Utilizing the 3D concave surface of the grinding wheel, the 3D surface tool marks of the metal exterior parts are repaired by repeatedly oscillating and grinding the tool marks on the metal exterior parts. S6 Repair 3D Concave Surface: After repairing a number of metal exterior parts, execute the 3D concave surface repair program and use the PCD polishing tool to repair the 3D concave surface of the 3D concave surface polymer grinding head. S7 loop: Repeat steps S5-S6 to achieve continuous operation.

2. The method for processing 3D surface tool marks on metal exterior parts as described in claim 1, characterized in that, In step S4, the tool holder includes a base plate with a fixed area, a support plate erected on the base plate, a U-shaped plate fixed to the top of the support plate, a notch for assembling a PCD planer tool recessed on the open end of the U-shaped plate, the open end of the U-shaped plate having two end faces, the notch penetrating either end face in a horizontal direction, and several threaded holes through the U-shaped plate, with screws passing through the threaded holes; the base plate is arranged horizontally, the support plate is arranged vertically, and the U-shaped plate is arranged horizontally, forming a Z-shaped structure with the base plate, support plate, and U-shaped plate connected vertically in sequence.

3. The method for processing 3D surface tool marks on metal exterior parts as described in claim 2, characterized in that, The fixed area is a strip groove formed on the base plate.

4. The method for processing 3D surface tool marks on metal exterior parts as described in claim 1, characterized in that, In step S5, when the 3D concave surface of the grinding wheel is used to repair the 3D surface grooves of the metal surface part, the repair amount per step is 0.02mm. The amount of material removed by the 3D concave surface of the grinding wheel in a single direction each time it contacts the 3D surface grooves of the metal surface part is 0.01mm.

5. The method for processing 3D surface tool marks on metal exterior parts as described in claim 4, characterized in that, The number of times the 3D concave surface of the grinding wheel is used to repeatedly vibrate and polish the 3D surface of the metal exterior part should not exceed 5.

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