Machining method of automobile lamp mould base

Abstract

The invention belongs to the technical field of mold machining, and discloses an automobile lamp mold frame machining method which comprises the following steps of S1, raw material pretreatment, S2, rough machining, S3, aging treatment, S4, finish machining, S5, surface treatment and S6, detection and debugging. According to the machining method of the automobile lamp mold frame, special materials and an innovative machining technology are adopted, the strength, toughness, machining precision and surface performance of the mold frame are improved, and therefore the defects in the prior art are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of mold processing, in particular to a processing method of an automobile lamp mold frame. Background Art

[0002] As the automotive industry develops towards intelligent and high-end technologies, consumers have placed higher demands on the appearance, lighting performance, and service life of automotive lights. As the core component of the automotive light injection mold, the performance and processing accuracy of the automotive light mold frame directly determine the quality and production efficiency of the automotive light products. However, the existing automotive light mold frame processing technology still has many bottlenecks: In terms of material application, traditional processing methods often use ordinary mold steel, whose strength, toughness, and wear resistance are insufficient to meet the requirements of automotive lamp mold frames. During the injection molding process, mold frames must withstand high temperatures, high pressures, and the impact of high-speed molten material. Ordinary steel is prone to fatigue cracks and deformation, shortening mold life and affecting the continuity and stability of automotive lamp production. For example, when producing LED lamps with complex curves, slight deformation of the mold frame due to insufficient material rigidity can reduce the optical surface accuracy of the headlight, thereby affecting the lighting effect. From a processing technology perspective, traditional milling and drilling methods suffer from low efficiency and poor precision. Automotive headlight molds often contain deep and narrow cooling channels, precision mounting holes, and complex parting surfaces. Conventional processing methods struggle to precisely control dimensional tolerances and surface roughness. For example, when machining cooling channels with a depth-to-diameter ratio exceeding 10:1, traditional deep-hole drilling can easily lead to rough hole walls and axis offset. This increases coolant flow resistance, impacts mold cooling efficiency, and prolongs the injection molding cycle. Furthermore, post-processing steps such as manual deburring and polishing are not only inefficient but also difficult to ensure process consistency, making product quality control more difficult. In the surface treatment process, existing technologies mostly use single chrome plating or passivation treatment, which cannot meet the comprehensive requirements of automotive lamp mold frames for corrosion resistance, wear resistance and demolding performance. Automotive lamps are exposed to complex environments for a long time during use. Mold frames after conventional surface treatment are prone to rust and wear, resulting in a decrease in mold surface finish, causing defects such as strains and scratches on the lamp surface, reducing product yield. At the same time, poor demolding performance increases the demolding force, aggravates mold frame surface wear, and further shortens the mold life. In summary, a processing method for automobile lamp mold frames is proposed. By optimizing material selection, innovating processing technology and improving surface treatment technology, the comprehensive performance and processing accuracy of the mold frame are improved to meet the growing high-quality demand of the automotive industry. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for processing an automobile lamp mold frame, which improves the strength, toughness, processing accuracy and surface properties of the mold frame by adopting special materials and innovative processing technology, thereby overcoming the defects of the prior art.

[0004] In order to achieve the above object, the present invention provides the following technical solutions: The technical solution provided by the present invention is: a method for processing an automobile lamp mold frame, comprising the following steps: S1. Raw Material Pretreatment: High-strength and tough alloy steel with a niobium content of 0.02-0.05wt% and a vanadium content of 0.05-0.1wt% is selected as the mold base blank. The blank is subjected to ultrasonic-eddy current composite flaw detection and equal channel angular extrusion (ECAP) treatment. Ultrasonic flaw detection uses a 2-5MHz probe with a sensitivity equivalent to a Φ2mm flat-bottom hole, and eddy current testing is performed at a frequency of 1-5kHz. ECAP treatment is performed at 400-500°C. The blank is subjected to 2-6 extrusion passes through a uniform cross-section channel with an angle of 90°-120°, refining the average grain size to ≤0.5μm. The pretreated blank has a tensile strength of 1200-1500MPa and an impact toughness of ≥80J / cm². S2. Rough machining: Rough milling is performed on the pre-treated blank using a five-axis CNC machine tool. The tool speed is controlled at 800-1500 rpm, the feed rate is 500-1000 mm / min, the cutting depth is 3-8 mm, and a 3-5 mm finishing allowance is reserved. S3. Aging treatment: Place the rough-machined mold frame in an aging furnace and keep it at 180-220℃ for 8-12 hours to eliminate internal stress. The furnace temperature should be controlled with an accuracy of ±5℃ and a uniformity error of ≤±10℃. S4. Finishing: Based on the 3D design model, precision machining is performed using a three-axis CNC machine tool with a positioning accuracy of ±0.005mm and a repeatability of ±0.003mm. A laser rangefinder monitors dimensional accuracy to ±0.01mm in real time. For complex structures such as deep and narrow grooves, abrasive flow machining is performed at a pressure of 0.5-2MPa for 20-60 minutes using a viscous fluid containing 10-50μm silicon carbide abrasive particles with a viscosity of 10-50Pa·s. S5. Surface treatment: Magnetron sputtering deposition of an AlTiN coating, pulse electrochemical deposition of a TiO2 self-cleaning coating, and passivation treatment are performed sequentially. The AlTiN coating is 0.5-1 μm thick and has a hardness ≥ 30 GPa. The deposition is performed at an argon-nitrogen volume ratio of 3:1-5:1 and a power of 100-300 W. The TiO2 coating is 50-100 nm thick and self-cleaning is achieved through photocatalysis. S6. Inspection and debugging: Use three-coordinate measuring machine, dial indicator and roughness tester to test dimensional accuracy, form and position tolerance and surface roughness respectively. After passing the test, proceed with mold assembly and debugging.

[0005] Furthermore, during the medium channel angular extrusion process in step S1, the roughness of the inner wall of the die channel Ra is less than or equal to 0.4 μm, and the extrusion speed is controlled at 0.1-1 mm / s.

[0006] Furthermore, in step S2, the five-axis CNC machine tool uses a carbide end mill with a cooling channel, a diameter of 10-20 mm, and is spray-cooled with a water-based cutting fluid at a pressure of 0.3-0.5 MPa.

[0007] Furthermore, in step S5, the magnetron sputtering deposition temperature is 150-250° C., the current density of the pulse electrochemical deposition TiO 2 coating is 5-15 mA / cm 2 , and the processing time is 10-30 minutes.

[0008] Furthermore, in step S6, the dimensional accuracy detection accuracy reaches ±0.002mm, the form and position tolerance detection straightness is ≤0.001mm / m, and the surface roughness Ra is ≤0.2μm.

[0009] The beneficial effects of this technical solution are: (1) In the material selection and pretreatment stages, the present invention selects high-strength and tough alloy steel containing niobium and vanadium, and combines it with equal channel angular extrusion (ECAP) processing technology to fundamentally change the microstructure of the mold frame material. Niobium and vanadium, as microalloying elements, form fine and dispersed carbonitrides in the steel, effectively hindering dislocation movement and grain growth. The ECAP treatment refines the grains to the submicron level (average grain size ≤ 0.5μm) through strong plastic deformation. Compared with traditional ordinary mold steel, the tensile strength of the mold frame processed by the present invention is increased from 800-1000MPa to 1200-1500MPa, an increase of 50%-60%; the impact toughness is increased from 40-60J / cm² to 80-95J / cm², an increase of approximately 50%-100%. This high-strength and high-toughness material property significantly enhances the mold frame's fatigue resistance when subjected to the high temperature, high pressure and high-speed melt impact during the injection molding process, effectively reducing the risk of cracking and deformation, extending the mold service life by 2-3 times, and significantly reducing the frequency of mold replacement and production costs.

[0010] (2) The use of ultrasonic-eddy current composite flaw detection technology has achieved high-precision detection of surface and internal defects of mold base blanks. Ultrasonic flaw detection can effectively detect large internal defects, while eddy current detection has high sensitivity to surface and near-surface micro-defects. The combination of the two can detect defects as small as Φ2mm flat-bottom hole equivalent. Compared with a single detection method, the defect recognition rate has increased from 80%-85% to more than 98%. This technology ensures the quality of the blank entering the subsequent processing link, avoids mold failure problems caused by material defects, improves the product qualification rate from the source, and reduces material waste and processing cost losses caused by scrap.

[0011] (3) In terms of processing technology, the coordinated application of five-axis CNC machine tools and three-axis CNC machine tools, combined with abrasive flow machining technology, has achieved a comprehensive improvement in mold frame processing accuracy and efficiency. The five-axis CNC machine tool can quickly remove a large amount of material in the rough processing stage. By optimizing the cutting parameters (rotation speed 800-1500r / min, feed speed 500-1000mm / min), the processing efficiency is improved by 30%-40% compared with traditional three-axis processing. In the fine processing stage, the high-precision three-axis CNC machine tool is combined with a laser rangefinder for real-time monitoring to control the dimensional accuracy within ±0.01mm, which is 3-5 times higher than the accuracy of traditional processing methods. Especially for complex structures such as deep and narrow grooves, abrasive flow machining technology is used to replace traditional manual deburring and polishing. It not only reduces the surface roughness from Ra0.8-1.6μm to Ra0.1-0.2μm, but also achieves a processing consistency of more than 99%. This effectively solves the problems of difficult to ensure the accuracy of complex structures and low efficiency in traditional machining, and meets the needs of high-precision manufacturing of automotive lamp molds.

[0012] (4) Multi-layer composite surface treatment technology gives the mold frame excellent comprehensive surface properties. First, the titanium aluminum nitride (AlTiN) coating deposited by magnetron sputtering has high hardness (≥30GPa) and good high-temperature oxidation resistance. Its hardness is 2-3 times higher than that of traditional chrome plating. It can effectively resist the erosion and wear of the melt in a high-temperature injection molding environment, reducing the scratches and scratches on the mold surface. Secondly, the nano titanium dioxide (TiO2) self-cleaning coating deposited by pulse electrochemical deposition can decompose surface organic pollutants through photocatalysis, making it difficult for oil and dust to adhere to the mold frame surface, greatly reducing the cleaning and maintenance frequency of the mold. In addition, the combination of composite coating and passivation treatment greatly improves the corrosion resistance of the mold frame, and the salt spray test life is extended from 500-800 hours to 1200-1500 hours, an increase of 1.5-2 times. It effectively adapts to the use requirements of automotive headlights exposed to complex environments for a long time, further improving the appearance quality and yield rate of automotive headlight products.

[0013] (5) The processing method of the present invention significantly improves the comprehensive performance and processing quality of automobile headlight molds through the above-mentioned technological innovations, thereby improving the quality and production efficiency of automobile headlight products. During the production process, the extended mold life reduces the number of mold changes and reduces downtime; high-precision processing ensures the consistency of product dimensions and improves the product qualification rate; excellent surface properties reduce product surface defects and reduce the scrap rate. Overall, production costs are reduced by 20%-30%, production efficiency is increased by 30%-40%, and product yield is increased from 85% to more than 98%. This makes the automobile headlight molds processed by the present invention more competitive in the market, can better meet the automotive industry's production needs for high quality, high efficiency and low cost, and has significant economic value and broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A step diagram of a method for processing an automobile lamp mold frame proposed by the present invention; Figure 2 This is a table of differences between various embodiments of a method for processing an automobile lamp mold frame proposed by the present invention; DETAILED DESCRIPTION

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0016] The specific implementation process is as follows: Example 1: See also Figure 1-2 The present invention provides a technical solution: a method for processing an automobile lamp mold frame, comprising the following steps: S1. Raw material pretreatment: High-strength and tough alloy steel with a niobium content of 0.02wt% and a vanadium content of 0.05wt% is selected as the mold frame blank material and cut into blanks with a size of 600mm×400mm×80mm; the mold frame blank is subjected to ultrasonic-eddy current composite flaw detection. The ultrasonic flaw detection uses a probe with a frequency of 2MHz and a detection sensitivity of Φ2mm flat-bottom hole equivalent. The eddy current detection equipment frequency is set to 1kHz. Through this composite detection method, tiny defects on the surface and inside of the blank are accurately detected, and undesirable defects are eliminated. Qualified blanks were then subjected to equal channel angular extrusion (ECAP) treatment. At a temperature of 400°C, the blanks were extruded through two equal-section channels of a die with an angle of 90°, and deformed in two passes. The surface roughness of the inner wall of the die channel was Ra ≤ 0.4μm, and the extrusion speed was 0.1mm / s. After treatment, the blank grains were refined to the submicron level, with an average grain size of 0.5μm, significantly improving the strength and toughness of the material, with a tensile strength of 1200MPa and an impact toughness of 80J / cm². S2. Rough Machining: A five-axis CNC machine tool performs rough machining on the pre-treated mold base blank. A 10mm diameter carbide end mill with a cooling channel is used. During machining, the tool speed is set at 800 rpm, the feed rate is 500 mm / min, and the cutting depth is 3 mm. The mold base's rough outline is machined, while a 3mm finishing allowance is reserved. During machining, a water-based cutting fluid at a pressure of 0.3 MPa is sprayed onto the tool and the machining area through the cooling channel to ensure machining stability and tool life. S3. Aging treatment: The rough-machined mold base is placed in an aging furnace for aging treatment. The aging temperature is set at 180°C and the holding time is 8 hours. The temperature in the aging furnace is controlled with an accuracy of ±5°C, and the temperature uniformity error during the holding process does not exceed ±10°C, to effectively eliminate the internal stress generated during the rough machining process. S4. Finishing: Based on the 3D design model, the aged mold base is finish-machined using a high-precision three-axis CNC machine with a positioning accuracy of ±0.005mm and a repeatability of ±0.003mm. A laser rangefinder monitors the machining dimensions in real time during machining to ensure a machining accuracy within ±0.01mm. For complex structures such as deep and narrow grooves on the mold base, abrasive flow machining is employed. A viscous fluid containing 10μm silicon carbide abrasive particles is circulated within the mold base channels at a pressure of 0.5MPa for 20 minutes, effectively removing residual burrs and improving surface quality. This completes the machining of the mold base's shape and mounting holes. S5. Multi-layer composite surface treatment: The finished mold base is surface treated. First, a 0.5μm thick layer of titanium aluminum nitride (AlTiN) coating is deposited on the mold base surface using magnetron sputtering deposition technology. The working gases during deposition are argon and nitrogen, with an argon-nitrogen volume ratio of 3:1, a deposition power of 100W, and a deposition temperature of 150°C. The coating has high hardness and good high-temperature oxidation resistance. Then, a 50nm thick nano-titanium dioxide (TiO2) self-cleaning coating is prepared on the surface of the titanium aluminum nitride (AlTiN) coating by pulse electrochemical deposition. The current density of the pulse electrochemical deposition is 5mA / cm², and the treatment time is 10 minutes. The surface self-cleaning function is achieved through photocatalysis. Finally, a passivation treatment is performed for 5 minutes to enhance the corrosion resistance of the mold base surface. S6. Inspection and commissioning: The mold base after surface treatment is fully inspected. Dimensional accuracy is tested using a three-dimensional coordinate measuring machine, form and position tolerances are checked using a dial indicator and a marble platform, and surface roughness is tested using a roughness meter. Once qualified, the mold base is installed in the automotive lamp mold for commissioning. The mold base is checked for proper fit with other mold components to ensure proper functioning of the mold. In Example 1, a high-strength and tough alloy steel with a niobium content of 0.02wt% and a vanadium content of 0.05wt% was selected and processed with equal channel angular extrusion (ECAP). At a temperature of 400°C, two equal-cross-section channels with a 90° angle in the mold were extruded in two passes to refine the grain size of the blank to an average grain size of 0.5μm. This effectively improved the basic performance of the material, with a tensile strength of 1200MPa and an impact toughness of 80J / cm². Compared with traditional ordinary mold steel, this significantly improves the strength and toughness, enhances the mold base's ability to resist deformation and fatigue during the injection molding process, and extends the service life of the mold. The application of ultrasonic-eddy current composite flaw detection technology significantly improves the defect recognition rate compared to single detection methods. It can accurately screen out qualified blanks, ensure the quality of mold bases from the source, avoid subsequent processing waste and mold failure risks caused by material defects, and reduce scrap rates. In terms of machining technology, rough machining on a five-axis CNC machine tool is combined with fine machining on a three-axis CNC machine tool, and laser rangefinders and abrasive flow machining technology are used to achieve an efficient and high-precision machining process. Rough machining quickly removes excess material, while fine machining controls dimensional accuracy within ±0.01mm. Abrasive flow machining effectively removes burrs and improves surface quality for complex structures, reducing surface roughness to an ideal level. Compared with traditional machining methods, this method has achieved significant improvements in both machining efficiency and precision. The surface treatment utilizes magnetron sputtering to deposit aluminum titanium nitride (AlTiN) coatings and pulse electrochemical deposition of self-cleaning nano-titanium dioxide (TiO2) coatings, imparting the mold frame with multiple properties, including high hardness, wear resistance, oxidation resistance, and self-cleaning properties. The AlTiN coating enhances the mold frame's surface resistance to molten material erosion and wear, while the TiO2 coating decomposes organic surface contaminants, reducing cleaning and maintenance frequency. The resulting mold frame remains rust-free for 1,200 hours in a salt spray test, demonstrating corrosion resistance far exceeding that of mold frames with conventional surface treatments. This effectively improves the appearance quality and yield rate of automotive lighting products, while reducing maintenance costs and scrap losses during production. In general, Example 1 comprehensively improves the material properties, processing accuracy and surface properties of the automobile headlight mold while ensuring a certain level of cost control. Compared with the existing technology, it shows significant advantages in the overall quality of the mold and production economy.

[0017] Example 2: See also Figure 1-2 The present invention provides a technical solution: a method for processing an automobile lamp mold frame, comprising the following steps: S1. Raw material pretreatment: High-strength and tough alloy steel with a niobium content of 0.05wt% and a vanadium content of 0.1wt% was selected as the mold frame blank material and cut into blanks measuring 550mm×350mm×90mm. The mold frame blanks were subjected to ultrasonic and eddy current composite flaw detection. The ultrasonic flaw detection used a 5MHz probe with a detection sensitivity of Φ2mm flat-bottom hole equivalent, and the eddy current detection equipment had a frequency of 5kHz. Defect-free blanks were strictly screened. The blanks were then subjected to equal channel angular extrusion (ECAP). At a temperature of 500°C, the blanks were extruded through two equal-section channels with a 120° angle in the mold, undergoing four passes. The surface roughness of the mold channel inner wall was Ra ≤ 0.4μm. At an extrusion speed of 1mm / s, the average grain size of the blank was refined to 0.3μm, significantly improving the material properties, with a tensile strength of 1500MPa and an impact toughness of 95J / cm². S2. Roughing: Rough machining is performed using a five-axis CNC machine tool, using a 20mm diameter carbide end mill and a water-based cutting fluid with a spray pressure of 0.5MPa in the tool cooling channel. During machining, the tool speed is set at 1500 rpm, the feed rate is 1000 mm / min, the cutting depth is 8 mm, and a 5mm finishing allowance is reserved to quickly produce the rough outline of the mold base. S3. Aging treatment: Place the rough-machined mold frame into an aging furnace, set the aging temperature to 220°C, and keep it warm for 12 hours. Use a high-precision temperature control system (temperature control accuracy is ±5°C, and temperature uniformity error does not exceed ±10°C) to fully eliminate the internal stress caused by rough machining; S4. Finishing: High-precision three-axis CNC machine tools (positioning accuracy ±0.005mm, repeatability ±0.003mm) are used for finishing based on the 3D design model. Laser rangefinders are used to monitor machining dimensions in real time, ensuring accuracy within ±0.01mm. Abrasive flow machining (AFM) is employed to address the complex structure of the mold base. A viscous fluid containing 50μm silicon carbide abrasive particles is circulated within the mold base channel at a pressure of 2MPa for 60 minutes, achieving high-precision machining and improved surface quality. S5. Multi-layer composite surface treatment: First, a 1μm-thick titanium aluminum nitride (AlTiN) coating is deposited on the mold surface using magnetron sputtering technology. The deposition process uses an argon-nitrogen volume ratio of 5:1, a deposition power of 300W, and a deposition temperature of 250°C. A 100nm-thick self-cleaning nano-titanium dioxide (TiO2) coating is then deposited on the AlTiN coating using pulsed electrochemical deposition at a current density of 15mA / cm² for 30 minutes. Finally, a 10-minute passivation treatment is performed to enhance the overall surface properties of the mold. S6. Inspection and debugging: Use a three-coordinate measuring machine, dial indicator, roughness tester and other equipment to conduct a comprehensive inspection of the mold base to ensure that all indicators meet the requirements. Then, install the mold base into the automotive lamp mold and debug it to ensure the normal operation of the mold. In Example 2, a high-strength and tough alloy steel with a niobium content of 0.05wt% and a vanadium content of 0.1wt% was extruded four times at 500°C through two equal-section channels in a mold with an angle of 120°. This resulted in a refined average grain size of 0.3μm, a tensile strength of 1500MPa, and an impact toughness of 95J / cm², significantly improving material performance. Compared with existing technologies, the higher strength and toughness enable the mold base to withstand greater injection pressure and impact, greatly improving the durability of the mold and meeting the long-term stable use requirements of high-end automotive headlight molds under complex working conditions. This significantly extends the mold replacement cycle and reduces overall production costs. During the inspection process, ultrasonic-eddy current composite flaw detection technology uses a higher detection frequency (ultrasonic 5MHz, eddy current 5kHz) to further improve the sensitivity and accuracy of detecting blank defects. The defect recognition rate is close to 100%, ensuring that every blank put into processing is of excellent quality, laying a solid foundation for the production of high-quality mold bases. During the machining process, the five-axis CNC machine tool uses a larger diameter tool and higher cutting parameters (tool diameter 20mm, rotation speed 1500r / min, feed rate 1000mm / min, cutting depth 8mm) for rough machining, which greatly improves material removal efficiency. Compared with traditional machining methods, the rough machining efficiency is increased by about 40%. In the finishing stage, the high-precision three-axis CNC machine tool combined with a laser rangefinder ensures machining accuracy within ±0.01mm. Abrasive flow machining with large-grain silicon carbide abrasive (50μm) and high pressure (2MPa) is used for complex structures. After 60 minutes of processing, the surface quality of the complex structure is greatly improved, the roughness is significantly reduced, and the processing consistency is good, which can meet the stringent requirements of high-end molds for high-precision machining of complex structures. In terms of surface treatment, the thicker AlTiN coating (1μm), higher deposition power (300W) and optimized argon-nitrogen ratio (5:1) enable the coating hardness to reach 35GPa, greatly improving the high-temperature oxidation resistance and allowing it to work stably in a high-temperature environment of 600°C; combined with a thicker TiO2 self-cleaning coating (100nm) and a long-term pulse electrochemical deposition treatment (30 minutes), a durable and self-cleaning protective layer is formed on the mold surface; the salt spray test life is extended to more than 1500 hours, the wear resistance is significantly improved, and the ability to resist erosion of the melt during the injection molding process is stronger, which greatly reduces the wear and scratches on the mold surface, effectively improving the appearance quality and production yield of the automotive lamp products, and showing strong performance advantages and market competitiveness compared with existing technologies in the field of high-end automotive lamp mold manufacturing.

[0018] Example 3: See also Figure 1-2 The present invention provides a technical solution: a method for processing an automobile lamp mold frame, comprising the following steps: S1. Raw material pretreatment: A high-strength and tough alloy steel with a niobium content of 0.03wt% and a vanadium content of 0.07wt% was selected and processed into a blank measuring 580mm × 380mm × 85mm. Ultrasonic-eddy current composite flaw detection was used, with an ultrasonic probe frequency of 3MHz and an eddy current test frequency of 3kHz, to detect and screen defects in the blank. Equal channel angular extrusion (ECAP) was then performed at 450°C, extruding the material through a 105° uniform cross-section channel in three passes. The die channel inner wall roughness Ra was ≤ 0.4μm, and the extrusion speed was 0.5mm / s. This resulted in grain refinement, resulting in an average grain size of 0.4μm, a tensile strength of 1350MPa, and an impact toughness of 88J / cm². S2. Roughing: A five-axis CNC machine tool was used with a 15mm diameter carbide end mill. The tool speed was 1200 rpm, the feed rate was 700 mm / min, the cutting depth was 6 mm, and a 4mm finishing allowance was reserved. Simultaneously, 0.4 MPa of water-based cutting fluid was sprayed through the tool cooling channel. S3. Aging treatment: Place the rough-machined mold frame in an aging furnace, set the temperature to 200°C, and keep it warm for 10 hours. Use a high-precision temperature control system (temperature control accuracy ±5°C, uniformity error ≤±10°C) to eliminate internal stress; S4. Finishing: A high-precision three-axis CNC machine tool (positioning accuracy ±0.005mm, repeatability ±0.003mm) is used for finishing based on a 3D model, with a laser rangefinder ensuring machining accuracy within ±0.01mm. For complex structures, abrasive flow machining is employed, with a viscous fluid containing 30μm silicon carbide abrasive particles circulating at a pressure of 1.2MPa for 40 minutes. S5. Multilayer composite surface treatment: First, a 0.8μm thick titanium aluminum nitride (AlTiN) coating was deposited by magnetron sputtering at an argon-nitrogen volume ratio of 4:1, a power of 200W, and a temperature of 200°C. Then, a 70nm thick nano-titanium dioxide (TiO2) self-cleaning coating was applied by pulse electrochemical deposition at a current density of 10mA / cm² for 20 minutes. Finally, a passivation treatment was performed for 8 minutes. S6. Inspection and debugging: The mold base is inspected by a three-coordinate measuring machine, a dial indicator and a roughness tester. After passing the inspection, it is installed and debugged; In Example 3, high-strength and tough alloy steel containing 0.03wt% niobium and 0.07wt% vanadium was treated through three passes of ECAP at 450°C and a 105° angle, refining the grains to an average grain size of 0.4μm. This resulted in a tensile strength of 1350MPa and an impact toughness of 88J / cm². Compared to conventional mold steel, this improved material performance allows the mold frame to maintain better structural stability during the injection molding process, reducing deformation caused by stress and extending the mold's service life. This also provides reliable assurance for the dimensional accuracy of the automotive lamp product. The application of ultrasonic-eddy current composite flaw detection technology can effectively detect surface and internal defects of blanks. Compared with existing single detection methods, it greatly improves the comprehensiveness and accuracy of detection, reduces the risk of mold production scrapping due to material defects, and saves raw material and processing costs. In terms of machining technology, the five-axis CNC machine tool rough machining uses moderate cutting parameters (tool diameter 15mm, rotation speed 1200r / min, feed speed 700mm / min, cutting depth 6mm). While ensuring machining efficiency, a reasonable 4mm finishing allowance is reserved to create good conditions for subsequent finishing. The three-axis CNC machine tool finishing uses a laser rangefinder to achieve real-time monitoring of dimensional accuracy, ensuring machining accuracy within ±0.01mm, meeting the high-precision requirements of the automotive headlight mold frame. For complex structures, abrasive flow processing containing 30μm silicon carbide abrasive particles and a pressure of 1.2MPa is used for 40 minutes to effectively remove residual burrs and improve surface quality. Compared with traditional manual processing methods, machining efficiency and quality consistency are significantly improved, ensuring the machining accuracy and surface finish of the complex structural parts of the mold frame. During the surface treatment phase, a 0.8μm-thick AlTiN coating is deposited by magnetron sputtering, combined with a 70nm-thick TiO2 self-cleaning coating deposited by pulse electrochemical deposition and an 8-minute passivation treatment. This creates a composite coating on the mold frame surface that combines high hardness, wear resistance, oxidation resistance, self-cleaning, and corrosion resistance. The AlTiN coating improves the hardness and wear resistance of the mold frame surface, effectively resisting the abrasion of the melt during the injection molding process. The TiO2 self-cleaning coating can decompose surface stains and reduce cleaning and maintenance work. The passivation treatment further enhances the mold frame's corrosion resistance. Testing has shown that the mold frame's salt spray test can meet the requirements of long-term rust-free performance. In actual production, it effectively reduces mold maintenance costs and improves the yield rate of automotive lamp products. Compared with existing technologies, in the production of conventional automotive lamp mold frames, it achieves a balance between production efficiency and cost control while ensuring product quality, and has good practicality and economy.

[0019] Example 4: See also Figure 1-2 The present invention provides a technical solution: a method for processing an automobile lamp mold frame, comprising the following steps: S1. Raw material pretreatment: A high-strength and tough alloy steel with a niobium content of 0.04wt% and a vanadium content of 0.09wt% was selected to produce blanks measuring 620mm×420mm×75mm. Qualified blanks were screened using ultrasonic-eddy current composite flaw detection at an ultrasonic frequency of 4MHz and an eddy current frequency of 4kHz. Equal channel angular extrusion (ECAP) was then performed at 480°C, with three passes through a uniform cross-section channel at a 110° angle. The die channel inner wall roughness Ra was ≤ 0.4μm, and the extrusion speed was 0.8mm / s. Grain refinement achieved an average grain size of 0.35μm, resulting in a tensile strength of 1420MPa and an impact toughness of 92J / cm². S2. Roughing: Using a five-axis CNC machine, an 18mm diameter carbide end mill was used. The cutter speed was 1300 rpm, the feed rate was 850 mm / min, the cutting depth was 7 mm, and a 4.5mm finishing allowance was reserved. A 0.45MPa water-based cutting fluid was sprayed in the cooling channels. S3. Aging treatment: Place the rough-machined mold frame in an aging furnace at 210°C for 11 hours. Use a high-precision temperature control system (temperature control accuracy ±5°C, uniformity error ≤±10°C) to eliminate internal stress. S4. Finishing: A high-precision three-axis CNC machine tool (positioning accuracy ±0.005mm, repeatability ±0.003mm) is used for finishing based on a 3D model. A laser rangefinder monitors the machine in real time to ensure accuracy within ±0.01mm. Complex structures are machined using abrasive flow machining, with a viscous fluid containing 40μm silicon carbide abrasive particles circulating at 1.5MPa for 50 minutes. S5. Multilayer composite surface treatment: First, a 0.9μm thick titanium aluminum nitride (AlTiN) coating was deposited by magnetron sputtering at an argon-nitrogen volume ratio of 4.5:1, a power of 250W, and a temperature of 220°C. Then, a 90nm thick nano-titanium dioxide (TiO2) self-cleaning coating was applied by pulse electrochemical deposition at a current density of 12mA / cm² for 25 minutes. Finally, a passivation treatment was performed for 9 minutes. S6. Inspection and debugging: Use three-coordinate measuring machine, dial indicator and roughness tester to inspect the mold base, and install and debug it after it passes the inspection; Example 4 uses high-strength and toughness alloy steel with a niobium content of 0.04wt% and a vanadium content of 0.09wt%. It undergoes three passes of ECAP treatment at 480°C through a 110° angle channel, successfully refining the grains to an average grain size of 0.35μm. The material achieves a tensile strength of 1420MPa and an impact toughness of 92J / cm², significantly improving its mechanical properties. Compared with conventional mold steels in the prior art, the higher strength and toughness significantly reduce the risk of deformation and damage to the mold frame when subjected to various stresses during the injection molding process, effectively extending the service life of the mold and improving production stability and continuity. The application of ultrasonic-eddy current composite flaw detection technology, with precise detection parameter settings, conducts comprehensive and detailed defect detection on blanks, greatly improving the accuracy of blank quality screening, avoiding subsequent processing losses caused by material defects, and providing a reliable material foundation for the production of high-quality mold bases; During the machining process, the five-axis CNC machine tool uses an 18mm diameter tool for rough machining, with a rotation speed of 1300r / min, a feed speed of 850mm / min, and a cutting depth of 7mm. While ensuring machining efficiency, a reasonable 4.5mm finishing allowance is reserved, creating favorable conditions for subsequent high-precision machining. The three-axis CNC machine tool combines a laser rangefinder to strictly control the machining accuracy within ±0.01mm, ensuring the high-precision requirements of the mold base size. For complex structures, abrasive flow machining containing 40μm silicon carbide abrasive grains and a pressure of 1.5MPa is used for 50 minutes, effectively improving the surface quality of the complex structure, removing residual burrs, and improving the surface finish. Compared with traditional machining methods, the precision and efficiency of complex structure machining are significantly improved, meeting the needs of mid-to-high-end automotive headlight mold bases for complex structure fine machining. In terms of surface treatment, a 0.9μm thick AlTiN coating is deposited by magnetron sputtering, and a 90nm thick TiO2 self-cleaning coating is deposited by pulse electrochemical deposition, followed by a 9-minute passivation treatment, to form a composite protective layer with excellent performance on the mold frame surface; the AlTiN coating gives the mold frame surface high hardness and good antioxidant properties, effectively resisting wear and high-temperature oxidation during the injection molding process; the TiO2 self-cleaning coating achieves self-decomposition of surface stains, reducing the workload of mold cleaning and maintenance; the passivation treatment further enhances the mold frame's corrosion resistance; after testing, the mold frame performed well in the salt spray test, with corrosion resistance far exceeding that of traditional mold frames. In actual production, it effectively reduces mold maintenance costs and improves the yield and appearance quality of automotive lamp products. In the field of mid-to-high-end automotive lamp mold manufacturing, compared with existing technologies, it has demonstrated significant performance advantages and higher production value, and can better meet the market demand for high-quality automotive lamp mold frames.

[0020] See also Figure 2 Examples 1-4 all use high-strength and toughness alloy steel containing niobium and vanadium. Compared with ordinary mold steel in the prior art, this technology optimizes the material from the essence. Through ECAP treatment, Example 1 refines the average grain size to 0.5μm and the tensile strength reaches 1200MPa; Example 2 further refines the grain size to 0.3μm and increases the tensile strength to 1500MPa. The tensile strength of ordinary mold steel in the prior art is usually 800-1000MPa. Through microalloying and special plastic deformation treatment, this technology makes the mold frame far superior to traditional products in strength and toughness, and can better withstand the high pressure, high temperature and melt impact during the injection molding process, reduce deformation and fatigue cracking, and extend the service life of the mold; All embodiments adopt ultrasonic-eddy current composite flaw detection technology. In Example 1, the ultrasonic frequency is 2 MHz and the eddy current frequency is 1 kHz. In Example 2, the ultrasonic frequency is 5 MHz and the eddy current frequency is 5 kHz. Different frequency combinations achieve high-precision detection of surface and internal defects of blanks. Compared with the single detection method of the existing technology, this technology can detect defects as low as Φ2mm flat-bottom hole equivalent, and the defect recognition rate is increased from 80%-85% of the existing technology to more than 98%, ensuring the quality of blanks entering subsequent processing links, avoiding mold failure during use due to material defects, and reducing scrap rate and cost waste. Rough machining stage: Examples 1-4 use a five-axis CNC machine tool, and according to different tool diameter, rotation speed, feed speed and cutting depth parameter settings, rapid material removal is achieved. For example, in Example 2, the tool diameter is 20 mm, the rotation speed is 1500 r / min, the feed speed is 1000 mm / min, and the cutting depth is 8 mm. Compared with traditional three-axis machining, the machining efficiency is improved by 30%-40%, and the general outline of the mold base is quickly formed; Finishing stage: Using a high-precision three-axis CNC machine tool and a laser rangefinder, the dimensional accuracy is controlled within ±0.01mm. For complex structures such as deep and narrow grooves, as in Examples 3 and 4, abrasive flow machining technology is used. In Example 1, 10μm silicon carbide abrasive particles are processed at a pressure of 0.5MPa for 20 minutes, and in Example 2, 50μm silicon carbide abrasive particles are processed at a pressure of 2MPa for 60 minutes. Different parameters are adapted to different structural requirements. Compared with traditional manual deburring and polishing, not only is the surface roughness reduced from Ra0.8-1.6μm in the existing technology to Ra0.1-0.2μm, but the processing consistency is also achieved to over 99%, solving the problem of low precision and low efficiency in traditional processing of complex structures. Each embodiment uses a multi-layer composite surface treatment technology to first deposit an AlTiN coating by magnetron sputtering, then pulse electrochemically deposit a TiO2 self-cleaning coating, and finally perform a passivation treatment. In Example 1, the AlTiN coating has a thickness of 0.5 μm, high hardness, and good oxidation resistance; the TiO2 coating has a thickness of 50 nm, achieving photocatalytic self-cleaning. In Example 2, the AlTiN coating has a thickness of 1 μm, and the hardness is further improved. Combining the TiO2 coating and passivation treatment, the salt spray test life of the mold frame is extended from 500-800 hours of the existing technology to 1200-1500 hours, and the corrosion resistance is greatly enhanced. At the same time, the high-hardness AlTiN coating effectively resists molten material erosion and wear, and the TiO2 coating reduces surface stain adhesion, reduces the frequency of mold maintenance, and improves the appearance quality and yield rate of automotive lamp products. This technology provides a variety of parameter combinations and process solutions through different embodiment settings. Embodiment 1 is suitable for the market demand of cost-sensitive and moderate performance requirements; Embodiment 2 is aimed at the manufacturing of high-end automotive lamp molds, pursuing ultimate performance; Embodiment 3 meets the universal requirements of conventional production; and Embodiment 4 is suitable for the mid-to-high-end market. The present invention significantly improves the performance and processing accuracy of automobile headlight mold frames through innovative raw material pretreatment, processing technology and surface treatment technology; in terms of materials, high-strength and tough alloy steel containing niobium and vanadium is combined with ECAP treatment to greatly improve the strength and toughness of the mold frame; the detection link adopts ultrasonic-eddy current composite flaw detection to effectively ensure the quality of the blank; during the processing, five-axis and three-axis CNC machine tools are combined with abrasive flow processing to achieve high-precision manufacturing of the mold frame; multi-layer composite surface treatment gives the mold frame good wear resistance, corrosion resistance and self-cleaning properties; compared with the existing technology, the mold frame processed by the present invention has significantly improved in mechanical properties, processing accuracy and surface properties, can better meet the use requirements of automobile headlight molds, and has good market application prospects.

[0021] The above is only an embodiment of the present invention, and common knowledge such as the specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A method for processing an automobile lamp mold frame, characterized in that: The following steps are involved: S1. Raw material pretreatment: A high-strength and tough alloy steel with a niobium content of 0.02-0.05wt% and a vanadium content of 0.05-0.1wt% is selected as the mold base blank. The blank is subjected to ultrasonic-eddy current composite flaw detection and equal channel angular extrusion (ECAP) treatment in sequence. The ultrasonic flaw detection uses a probe with a frequency of 2-5MHz and a detection sensitivity of a Φ2mm flat-bottom hole equivalent, and the eddy current testing frequency is 1-5kHz. The ECAP treatment is carried out at 400-500°C. The blank is subjected to 2-6 extrusion passes through a uniform cross-section channel with an angle of 90°-120° to refine the average grain size to ≤0.5μm, obtaining a pretreated blank with a tensile strength of 1200-1500MPa and an impact toughness of ≥80J / cm². S2. Rough machining: Rough milling is performed on the pre-treated blank using a five-axis CNC machine tool. The tool speed is controlled at 800-1500 rpm, the feed rate is 500-1000 mm / min, the cutting depth is 3-8 mm, and a 3-5 mm finishing allowance is reserved. S3. Aging treatment: Place the rough-machined mold frame in an aging furnace and keep it at 180-220℃ for 8-12 hours to eliminate internal stress. The furnace temperature should be controlled with an accuracy of ±5℃ and a uniformity error of ≤±10℃. S4. Finishing: Based on the 3D design model, precision machining is performed using a three-axis CNC machine with a positioning accuracy of ±0.005mm and a repeatability of ±0.003mm. A laser rangefinder monitors dimensional accuracy to ±0.01mm in real time. For complex structures such as deep and narrow grooves, abrasive flow machining is performed using a viscous fluid containing 10-50μm silicon carbide abrasive particles with a viscosity of 10-50Pa·s at a pressure of 0.5-2MPa for 20-60 minutes. S5. Surface treatment: sequentially magnetron sputtering deposition of AlTiN coating, pulse electrochemical deposition of TiO2 self-cleaning coating and passivation treatment; the AlTiN coating thickness 0.5-1μm, hardness ≥30GPa, deposition argon nitrogen volume ratio 3:1-5:1, power 100-300W; the TiO2 coating thickness 50-100nm, by photocatalytic surface self-cleaning; S6. Inspection and debugging: Use three-coordinate measuring machine, dial indicator and roughness tester to test dimensional accuracy, form and position tolerance and surface roughness respectively. After passing the test, proceed with mold assembly and debugging.

2. The processing method according to claim 1, characterized in that: During the medium channel angular extrusion process in step S1, the roughness of the inner wall of the die channel Ra is less than or equal to 0.4 μm, and the extrusion speed is controlled at 0.1-1 mm / s.

3. The processing method according to claim 1, characterized in that: In step S2, the five-axis CNC machine tool uses a carbide end mill with a cooling channel, a diameter of 10-20 mm, and is spray-cooled with a water-based cutting fluid at a pressure of 0.3-0.5 MPa.

4. The processing method according to claim 1, characterized in that: In step S5, the magnetron sputtering deposition temperature is 150-250° C., the current density of the pulse electrochemical deposition TiO 2 coating is 5-15 mA / cm 2 , and the processing time is 10-30 minutes.

5. The processing method according to claim 1, characterized in that: In step S6, the dimensional accuracy detection accuracy reaches ±0.002mm, the form and position tolerance detection straightness is ≤0.001mm / m, and the surface roughness Ra is ≤0.2μm.

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