Method for repairing damaged automobile lampshade

Abstract

The invention discloses an automobile lampshade damage repairing method, and belongs to the technical field of automobile maintenance. Preparing a repairing base body: grinding the damaged part into a composite structure in a stepped manner by using grinding equipment by taking the damaged part as a center; comprising the following steps: forming a feathering transition area: polishing two sides along a damage center line to form an area with smooth and concave surface and gradually changed depth and width; a damaged material is removed from the center of the bottom of the feathering transition area along a damage path, and the flow guide grooves with the uniform width are ground; and the edges of the two sides of the diversion trench are finely thinned and polished into transparent thin-layer areas. Cleaning and sealing. And glue injection and curing: injecting the repairing resin into the glue injection cavity, and irradiating and curing by using an ultraviolet lamp after permeating and filling. And grinding and leveling. And polishing reduction: polishing the processing area to recover the surface gloss of the lampshade. According to the method, through the design of the stepped repairing base body, the problem that damage marks are obvious in traditional repairing is fundamentally solved.

Description

Technical Field

[0001] This invention relates to the field of automotive repair technology, and more specifically, to a method for repairing damaged automotive lamp covers. Background Technology

[0002] Damaged car headlight covers are a common problem during vehicle use, caused by a variety of factors, such as external impacts, uneven material expansion and contraction due to sudden temperature changes, and aging and brittleness caused by prolonged exposure to ultraviolet radiation. Once the headlight cover is damaged, it not only affects the car's appearance, but more importantly, it allows moisture, dust, and other impurities to enter the headlight, affecting its lighting performance and even damaging the bulb and circuit components, posing a safety hazard.

[0003] Traditional methods often involve replacing the entire headlight cover or headlight assembly. While direct and effective, this approach is costly. Traditional headlight cover repair simply involves sanding the damaged area and applying repair glue. Because of differing understandings of light and shadow on objects, this method often leaves visible signs of damage after repair, resulting in less than ideal results. Summary of the Invention

[0004] To address the issue of repair marks in existing automotive lamp cover repair techniques, this invention aims to provide a method for repairing damaged automotive lamp covers. This method constructs a stepped repair substrate and combines adhesive injection curing and surface treatment processes to achieve high-strength, low-mark repair of damaged or torn lamp covers, thus solving the problems of existing technologies.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows: A method for repairing damaged car headlight covers, characterized in that, S1. Disassemble and clean: Remove the damaged lens cover from the car headlight assembly and clean it; S2. Preparation of stepped repair matrix: Using grinding equipment, a stepped grinding process is carried out with the damaged area as the center, forming a composite structure of feathering transition zone, guide channel and cicada wing zone in sequence; S21. Forming a feathering transition zone: Using the damage as the center line, polish the areas on both sides to form a smooth, concave area with a depth and width that gradually change in all directions. S22. Create a guide channel: At the bottom center of the feathering transition zone, completely remove the damaged material along the damage path and grind to form a guide channel of uniform width. S23. Forming the cicada wing area: The two sides of the guide channel are finely thinned and polished to form a transparent thin layer area; S3. Cleaning and sealing the cavity after adhesive injection: S31. Thoroughly remove all sanding residue; S32. On the inner side of the lampshade, in the area corresponding to the guide groove, a sealing film is pasted to completely cover and seal the guide groove, thereby forming a glue injection cavity with the lampshade to accommodate the repair resin. S4. Adhesive application and curing: The repair resin is injected into the injection cavity, allowing it to naturally penetrate and completely fill the cavity; then, it is irradiated with ultraviolet light or heated to completely cure the repair resin. S5. Grinding and leveling: Grind the raised parts of the cured repair resin to make its surface smoothly connect with the surrounding area; S6. Surface treatment: The ground and leveled area is then finished to make its appearance the same as or similar to the surrounding unrepaired lampshade surface.

[0006] This method fundamentally solves the problem of obvious damage marks in traditional repairs through a stepped substrate design. The smooth, concave structure of the feathered transition zone provides ample space for subsequent resin filling. Simultaneously, the gradual change in depth and width ensures a natural connection between the repaired resin and the original lampshade surface, avoiding abrupt boundaries. The guide channels precisely target the damage path, thoroughly removing damaged material and allowing the repair resin to directly act on the core damaged area, enhancing repair strength. The transparent thin-layer design of the cicada wing zone further optimizes the optical properties of the cured resin, reducing light refraction differences and thus lowering the visibility of repair marks. The application of a sealing film creates a closed injection cavity, ensuring complete resin filling while preventing resin leakage, improving repair reliability. Subsequent grinding and finishing processes meticulously process the repaired area, fully restoring the lampshade's appearance and transparency. This results in a repaired lampshade that achieves ideal results in both strength and aesthetics, significantly reducing repair costs compared to replacing the entire assembly, demonstrating significant economic value and practical significance.

[0007] In a method for repairing damaged automotive lampshades according to this application, further, in step S21, the width of the feathered transition zone is 10-60 mm, and its deepest point at the center is 50%-90% of the thickness of the lampshade substrate, smoothly transitioning towards the edge to be flush with the original surface of the lampshade. The 10-60 mm width of the feathered transition zone can accommodate damage of different lengths and severity, ensuring sufficient area to accommodate the repair resin and form an effective transition. The wider the feathered transition zone, the gentler the curvature transition between the filled resin and the lampshade substrate, and the closer the light transmission effect between the different materials (lampshade substrate and filling resin) after repair. The design of smoothly transitioning towards the edge to be flush with the original surface provides a good transition for subsequent grinding and polishing processes, ensuring a natural integration of the repaired area with the surrounding non-repaired areas.

[0008] In a method for repairing damaged automotive lamp covers according to this application, further, in step S22, the width of the guide channel is 1~30mm, which penetrates the entire substrate of the lamp cover repair area. The width range of 1~30mm for the guide channel can be adjusted according to the actual width and depth of the damage. For small damage (damage ≤10mm in length), a narrower width can be selected to ensure that damaged material and impurities within the damage can be completely removed. For wider damage or damage with slight breakage, the width can be appropriately increased to provide more sufficient space for resin filling.

[0009] In a method for repairing damaged automotive lamp covers according to this application, further, in step S23, the width of the cicada wing area is 3-10mm, and its remaining thickness after polishing is no more than 0.3mm. This parameter setting is one of the key technical details for achieving low-mark repair. The width of 3-10mm ensures that the cicada wing area can fully cover the optical areas on both sides of the guide groove, providing sufficient transition space for light transmission between the repair resin and the original lamp cover material. The remaining thickness of the cicada wing area is no more than 0.3mm, which, after combining with the cured repair resin, can minimize the difference in refraction and reflection of light at the interface between the two different media (original lamp cover material and repair resin), making the light transmission performance of the repaired area as close as possible to the original lamp cover, thus making the repair marks difficult to detect visually. This light transmission performance close to the original lamp cover effect is something that traditional repair methods cannot achieve by simply filling the damage, greatly improving the aesthetics and overall harmony after repair.

[0010] In a method for repairing a damaged automotive lamp cover according to this application, the criterion for determining whether the polishing of the "cicada wing" area is qualified is as follows: the lamp cover is placed in clean water, and the "cicada wing" area is visually invisible in the water. This criterion is a visual verification method based on the ultra-thin and transparent characteristics of the "cicada wing" area. The clear water environment can fully immerse the polished "cicada wing" area (transparency, thinness, and invisibility after polishing), allowing light to pass through the area smoothly, simulating the light transmission effect after the repair resin has immersed the "cicada wing" area. When the "cicada wing" area is visually invisible in the water, it indicates that its thinning and polishing has achieved the expected light transmission effect. At this time, its thickness and light transmittance can meet the requirements for optical performance matching after subsequent resin filling, effectively avoiding the appearance of traces caused by uneven thickness or light transmission differences in the "cicada wing" area itself after repair.

[0011] In a method for repairing damaged automotive lamp covers according to this application, further, in step S23, before grinding the wing area, a shim that conforms to the lamp cover is placed on the back of the lamp cover's grinding surface. This shim is made of flexible polyurethane material with the same curvature as the lamp cover, and its thickness is unlimited. Its function is to provide rigid support for the lamp cover during grinding, preventing deformation of the lamp cover substrate due to grinding pressure, and simultaneously preventing the grinding tool from directly contacting non-processed areas of the lamp cover and causing accidental damage.

[0012] In a method for repairing a damaged car headlight cover according to this application, further, after the sealing film is pasted in step S32, the edge of the cicada wing area is finely polished to eliminate the step between the edge of the cicada wing area and the sealing film.

[0013] In a method for repairing a damaged automotive lamp cover according to this application, further, in step S33, after step S2 is completed, a fence is bonded to the outer ring of the feathering transition zone to prevent the repair resin injected into the feathering transition zone from overflowing. Adhesive tape or a 3D printed pen can be used to add the fence around the repair area, with the height slightly higher than the highest point of the damaged area to prevent dripping.

[0014] In a method for repairing a damaged car headlight cover according to this application, further, in step S4, after the repair resin has fully cured, the sealing film and the fence are removed first, and then the grinding is carried out in step S5.

[0015] In a method for repairing a damaged automotive lamp cover according to this application, further, in step S6, a polishing wheel and polishing paste are used to polish the grinding area of ​​the lamp cover; and after polishing, the transparency is restored.

[0016] In one method for repairing damaged automotive lamp covers in this application, an anti-oxidation coating is further applied to the lamp cover to complete the surface hardening treatment of the lamp cover.

[0017] In a method for repairing damaged automotive lamp covers according to this application, further, in step S4, different repair resins are selected according to the damaged location and size, and preheating and multi-stage curing processes are performed, specifically including: S41. Selection of Repair Resin: If the damage is located at the edge of the lampshade and is accompanied by missing material, or if the damage is located in a non-edge area of ​​the lampshade (area <20mm from the edge of the lampshade) and is longer than 30mm, then transparent epoxy structural adhesive should be used as the repair resin. If the damage is in other parts of the lampshade, then UV-cured resin should be used as the repair resin. Transparent epoxy structural adhesive has high-strength bonding performance and excellent structural stability, which can effectively cope with the complex stress problems caused by missing edge material or large damage (damage >30mm in length, or damage accompanied by missing material), ensuring that the repaired area has sufficient impact resistance and durability. UV-cured resin, on the other hand, has the characteristics of fast curing speed and convenient operation, and is suitable for repairing relatively minor damage. It can be rapidly cured under ultraviolet light, improving repair efficiency.

[0018] S42. Preheating and Stress Relief: Before applying the adhesive, heat the lampshade in a constant temperature chamber to 60℃~90℃ and maintain this temperature for 5~10 minutes, then remove it and allow it to cool naturally to room temperature. The core purpose of this step is to release the internal stress accumulated in the lampshade material due to previous sanding and long-term use through gentle heating and natural cooling. Setting the heating temperature to 60℃~90℃ activates the movement of material molecules, promotes the relaxation and release of internal stress, and keeps it below the heat distortion temperature of the lampshade substrate to avoid overheating leading to deformation or performance degradation. Maintaining the temperature for 5~10 minutes ensures uniform heat penetration, allowing for more complete stress release. After heating, allow the lampshade to cool naturally to room temperature. This slow cooling process facilitates the rearrangement and stabilization of material molecules, reducing the risk of cracking due to uneven shrinkage stress in the repaired area during subsequent adhesive curing and use, or poor bonding between the repair resin and the substrate, laying the foundation for improved long-term stability of the repair.

[0019] S43. Staged adhesive application and curing: The repair resin is injected into the injection cavity in multiple stages. The first injection comprises 10%-30% of the total repair resin, ensuring it covers and wets the cavity surface, especially the fine structures of the channel grooves and wing-shaped areas, guaranteeing good wetting and initial bonding between the resin and the cavity wall. Subsequently, preliminary curing is performed depending on the resin type: for UV-cured resins, pre-irradiation with ultraviolet light until semi-cured, forming a tacky and supportive underlayer; for transparent epoxy structural adhesives, initial curing is completed by allowing it to stand at room temperature for an appropriate time.

[0020] Subsequently, the remaining repair resin is injected evenly each time, ensuring complete filling of the injection cavity, especially the deeper parts of the feathering transition zone. After injection, the lamp cover is gently shaken to utilize the resin's fluidity to spread the adhesive evenly, eliminating air bubbles and ensuring that even the smallest gaps are fully filled. Final curing is then performed: UV-cured resin is thoroughly irradiated with a UV lamp for a sufficient duration; transparent epoxy structural adhesive, depending on its curing characteristics, can be left to stand at room temperature or moved to a constant temperature oven for accelerated curing. This multi-stage injection and curing process avoids problems such as air bubble encapsulation, stress concentration due to curing shrinkage, and insufficient filling associated with large-volume single injections, thus improving the bonding strength between the repair resin and the substrate and the overall performance of the repaired area.

[0021] In a method for repairing damaged automotive lamp covers according to this application, further, when using transparent epoxy structural adhesive, in step S43: After the initial injection of the repair resin, allow it to stand at room temperature for 20-30 minutes to complete the initial curing. Inject the remaining repair resin in sequence, spread it evenly, and let it stand to cure, or move the lamp cover into a constant temperature chamber and heat it at 60℃~90℃ for 10~15 minutes to cure, and then take it out to cool.

[0022] In a method for repairing damaged automotive lamp covers according to this application, further, in step S6, for colorless transparent lamp covers, the finishing process is polishing; for colored transparent lamp covers, the finishing process is polishing or surface texture restoration treatment. Surface texture restoration treatment includes, but is not limited to, sanding with sandpaper with a grit size of 240~2000 grit, surface ultraviolet coating restoration, and other treatment methods. The beneficial effects of this application are:

[0023] This invention fundamentally solves the problem of obvious damage marks in traditional repairs through a stepped repair substrate design. The smooth, concave structure of the feathered transition zone provides ample space for subsequent resin filling. Simultaneously, the gradual change in depth and width ensures a natural connection between the repaired resin and the original lampshade surface, avoiding abrupt boundaries. The guide channels precisely target the damage path, thoroughly removing damaged material and allowing the repair resin to directly act on the core damaged area, enhancing repair strength. The transparent thin-layer design of the cicada wing zone further optimizes the optical properties of the cured resin, reducing light refraction differences and thus lowering the visibility of repair marks. The application of a sealing film creates a closed injection cavity, ensuring complete resin filling while preventing resin leakage, improving repair reliability. Subsequent grinding and finishing processes refine the repaired area, fully restoring the lampshade's appearance and gloss. This results in a repaired lampshade that achieves ideal results in both strength and aesthetics, significantly reducing repair costs compared to replacing the entire assembly, demonstrating significant economic value and practical significance. Attached Figure Description

[0024] Figure 1 This is a schematic cross-sectional view of the injection cavity structure of this application; Figure 2 For this application Figure 1 Enlarged view of point A; Figure 3 A photograph of the original damaged and feathering transition zone of this application after polishing; Figure 4 A physical image of the polished guide channel for this application; Figure 5 A photograph of the polished cicada wing area of ​​the lampshade in this application; Figure 6 A photograph of the actual lampshade with the sealing film attached to it, as per this application. Figure 7 A photograph of the lampshade being glued for this application; Figure 8 This is a photograph of the lampshade grinding and leveling process described in this application. Figure 9 This is a photograph of the polished and restored lampshade of this application; Figure 10 This is a photograph of the object after polishing and testing in water. Figure 11 This is a photograph of the lampshade after the repair was completed according to this application. Label Explanation: 1. Feathering transition zone; 2. Cicada wing zone; 3. Guide channel; 4. Injection cavity; 5. Sealing film; 6. Damage; 7. Fence. Detailed Implementation

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal," etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for better description of this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. Example 1

[0026] like Figures 1-2 As shown, this application provides a method for repairing damaged automotive lamp covers, including: S1. Disassembly and Cleaning: Remove the lamp cover with damage 6 from the car light assembly and clean it. The specific steps for S1 are as follows: Clean the inner and outer surfaces of the lamp cover, paying special attention to removing oil, dust, and adhesive residue around damage 6, ensuring that there are no impurities attached to the repair area, and finally rinse it with clean water and let it air dry or blow it dry with compressed air.

[0027] S2. Preparation of a stepped repair substrate: The six damaged areas of the lampshade are polished to form a stepped repair substrate, specifically including: S21. Grinding to form feathered transition zone 1: Using the damaged area 6 as the center line, grind the areas on both sides to form a smooth, concave area with a gradually changing depth and width towards the edges. Specifically, using a ball-head grinder or sandpaper with a grit of 80-180 grit, grind along a direction perpendicular to the direction of the damaged area 6, forming a feathered transition zone 1 that is deep in the center and shallow at the edges. The width of the feathered transition zone 1 is 10-60mm, and its deepest point at the center is 50%-90% of the thickness of the lampshade substrate, smoothly transitioning towards the edges to be flush with the original surface of the lampshade. During the grinding process, grinding debris needs to be continuously cleaned, and the transition zone surface should be smooth, without obvious grinding marks, and with uniform depth changes, as observed by side lighting.

[0028] S22. Grinding to form a guide groove 3: At the center of the feathering transition zone 1, i.e., where the damage 6 is located, a guide groove 3 penetrating the lampshade substrate is formed by grinding along the direction of the damage 6. Specifically, a grinding machine with a ball head, sandpaper with a grit of 80~120 grit, or a ball end mill is used to grind along the direction of the damage 6 to remove all the substrate material of the damage 6.

[0029] S23. Grinding to form the cicada wing area 2: On both sides of the guide channel 3, within the feathering transition area 1, grind to form the cicada wing area 2. The width of the cicada wing area 2 is 3~10mm, and the specific width is adapted according to the width of the guide channel 3 and the size of the feathering transition area 1. When grinding, use sandpaper with a grit of 240~2000 grit and grind with appropriate force to make the remaining thickness of the cicada wing area 2 no more than 0.3mm. The criterion for judging whether the grinding is qualified is: place the lampshade in clean water, and visually inspect the cicada wing area 2. If it is not visible in the water, continue to fine-tune the grinding until it meets the standard. During grinding, place an elastic pad that fits the lampshade substrate on the reverse side of the grinding surface of the lampshade. The pad is made of flexible polyurethane material with the same curvature as the lampshade, and the thickness is unlimited. Its function is to provide rigid support for the lampshade during the grinding process, prevent the lampshade substrate from deforming due to grinding pressure, and at the same time avoid the grinding tool from directly contacting the non-processed area of ​​the lampshade to avoid accidental damage.

[0030] S3. Cleaning and sealing the cavity: S31. Clean the lampshade with water to thoroughly remove all sanding residue. Drying treatment: Place the pre-treated lampshade in a constant temperature drying oven, set the temperature to 60~70℃, and dry for 5~10 minutes to remove any residual moisture on the surface of the lampshade and inside the damaged area after sanding, preventing moisture from affecting the bonding performance between the repair resin and the substrate. Alternatively, compressed air can be used to quickly dry and clean the surface of the lampshade.

[0031] S32. Applying Sealing Film 5: Apply sealing film 5 to the outer surface of the non-repair area (back side) of the lampshade for protection. The sealing film 5 (typically a 0.1mm thick PET adhesive film) covers the feathering transition area 1, the wing area 2, and the guide groove 3 of the lampshade, as well as at least 20mm of the surrounding back area. Use your fingers to slowly scrape and press from the center of the repair area outwards to remove air between the sealing film and the lampshade surface, ensuring a tight fit without bubbles or wrinkles. After application, finely sand the edges of the wing area 2 to eliminate any steps between the edge of the wing area 2 and the sealing film 5, creating a smooth transition. During sanding, be careful not to sand through the sealing film 5 to prevent resin leakage during adhesive application.

[0032] S33. Use tape to attach a fence around the outer ring of the feathering transition zone 1 to prevent the repair resin injected into the feathering transition zone from overflowing.

[0033] S4. Injection and Curing: Select different repair resins according to the damaged part and size of the damage 6, and perform preheating and multi-stage curing treatment.

[0034] S41. Selection of repair resin: If the damage 6 is located at the edge of the lampshade and is accompanied by missing material, or if the damage 6 is located in the non-edge area of ​​the lampshade (the non-edge area refers to the area ≥20mm away from the edge of the lampshade) and the length exceeds 30mm, then transparent epoxy structural adhesive shall be selected as the repair resin; if the damage 6 is in other parts of the lampshade, then light-cured resin shall be selected as the repair resin.

[0035] S42. Preheating and stress release: Before applying the adhesive, place the lampshade in a constant temperature chamber and heat it to 60℃~90℃ for 5~10 minutes. Then remove it and let it cool naturally to room temperature.

[0036] S43. Staged adhesive application and curing: The repair resin is injected in multiple stages into the injection cavity 4 formed by the sealing film 5 and the lampshade surface. The first injection is 10%-30% of the total repair resin. The resin is slowly injected into one end of the guide groove 3, allowing it to flow naturally, covering and wetting the surface of the injection cavity 4, especially the fine structures of the guide groove 3 and the cicada wing area 2, ensuring good wetting and initial bonding between the resin and the inner wall of the injection cavity 4. Subsequently, preliminary curing is performed according to the resin type: if it is a light-curing resin, a 365nm ultraviolet lamp is used, 10-15cm away from the lampshade surface, for a short time (usually 30-60 seconds) until curing, forming a supporting base layer; if it is a transparent epoxy structural adhesive, it is allowed to stand at room temperature for 20-30 minutes to complete the initial gelation.

[0037] The remaining repair resin is then injected multiple times, slowly from one end of the guide channel 3, until the resin fills the entire injection cavity 4, especially the deeper parts of the feathering transition zone 1. The resin surface is slightly higher than the surface of the sealing film 5. The resin's fluidity is used to spread the adhesive evenly, eliminating air bubbles. This can be confirmed by observing under side light to ensure no air bubbles remain. The final curing process is then performed: the UV-cured resin is fully irradiated with a UV lamp for a sufficient time (usually 3-10 minutes, depending on the resin thickness and curing requirements) to ensure complete curing; the transparent epoxy structural adhesive is allowed to cure statically or the lamp cover is moved into a constant temperature chamber and heated at 60℃-90℃ for 10-15 minutes, then removed and cooled to room temperature.

[0038] S5. Grinding: After the repair resin has fully cured, carefully remove the sealing film 5. Use a ball-head grinder to initially grind the repair area, removing any cured resin protruding above the lampshade surface. Grind in the same direction to avoid creating deep scratches from cross-grinding. Once the repair area is basically flush with the lampshade surface, change to sandpaper for fine grinding to further refine the surface roughness. At this stage, apply even pressure to ensure a natural transition between the repaired area and the surrounding non-repaired areas. During the grinding process, continuously rinse the grinding surface with clean water and observe the grinding progress to prevent over-grinding and damage to the non-repaired areas.

[0039] S6. Surface treatment: For colorless transparent lampshades, use a polishing wheel and polishing compound to polish the polishing areas of the lampshade. Use a wool wheel or sponge wheel for polishing. First, use a coarse-grained polishing compound (e.g., 3μm) for the first polishing to remove traces left by fine grinding. Then, switch to a fine-grained polishing compound (e.g., 1μm) for the second polishing, until the repaired area achieves a mirror finish. Finally, spray an anti-oxidation UV coating onto the lampshade using a low-pressure spray gun, holding it 20-30cm away from the lampshade surface. Spray 1-2 coats evenly and irradiate with a UV mercury lamp for 40-60 seconds to harden the lampshade surface, improving the wear resistance and anti-aging properties of the repaired area.

[0040] For colored transparent materials, polishing or surface texture restoration is performed using the methods described above. Surface texture restoration includes, but is not limited to, fine polishing with sandpaper of 240-2000 grit or surface UV coating to make its appearance consistent with the surrounding unrepaired lampshade surface.

[0041] S7. Assembly: After the anti-oxidation coating has completely dried and cured, conduct an appearance inspection and light transmission performance test on the repaired lamp cover. After confirming that there are no obvious repair marks, uniform light transmission and no defects such as bubbles or damage, reinstall the lamp cover back into the car lamp assembly, reassemble it in the reverse order of disassembly, connect the power supply, and test the lighting effect of the car lamp to ensure that the light illumination angle, brightness and other aspects meet the requirements. Example 2

[0042] Following the method provided in Example 1, a strip of car headlight cover approximately 3cm long was selected to repair the damaged area 6. The specific repair steps and results are as follows: S1. Disassembly and cleaning: Wipe and clean the inner and outer surfaces of the lampshade with damage 6, then rinse it with clean water and let it air dry or blow it dry with compressed air.

[0043] S2. Preparation of a stepped repair substrate: Centered on the damage 6, use a spherical grinder with 80-180 grit sandpaper to grind outwards in a direction perpendicular to the direction of the damage 6, forming a feathered transition zone 1 with a width L1 of approximately 20mm, a central depth of 2mm (3mm thick lampshade), and shallow edges (e.g., Figure 3 (As shown). During the polishing process, polishing debris needs to be continuously cleaned. Observe under side lighting to ensure that the surface of the transition area is smooth, without obvious polishing marks, and that the depth change is uniform.

[0044] S22, Grinding to form guide groove 3 (e.g.) Figure 4 (As shown): Use a grinder with a ball head, sandpaper with a grit of 80-120 mesh, or a scraper to grind along the direction of the damage 6 to remove all the damaged substrate at the damage 6. The width L2 of the grinding guide groove 3 is approximately 10mm.

[0045] S23, Polishing to form cicada wing area 2 (as shown) Figure 5 (As shown): On both sides of the guide channel 3, within the feathering transition zone 1, use a ball-head grinder and / or sandpaper with a grit of 240~2000 to continue grinding to form the cicada wing zone 2. During the grinding process, a shim that fits the lampshade substrate can be placed on the reverse side of the grinding surface of the lampshade. This shim is made of flexible polyurethane material with a thickness of 3mm and the same curvature as the lampshade. The grinding width L3 of the cicada wing zone 2 is approximately 4mm. When grinding, a gentle force should be used for fine grinding to ensure that the remaining thickness of the cicada wing zone 2 is no more than 0.3mm. The criterion for judging whether the grinding is qualified is: place the lampshade in clean water. If the cicada wing zone 2 is not visible in the water, it needs to be finely adjusted until it meets the standard. When the remaining thickness of the cicada wing zone is ≤0.3mm, it is not visible when placed in clean water; if it is visible, it needs to be further thinned and ground until the thickness is ≤0.3mm.

[0046] S33. Use tape to attach a fence around the outer ring of the feathering transition zone 1 to prevent the repair resin injected into the feathering transition zone from overflowing.

[0047] S3. Cleaning and sealing the cavity: S31. Clean the lampshade with water to thoroughly remove all polishing residue. Drying treatment: Place the pre-treated lampshade in a constant temperature drying oven, set the temperature to about 70℃, and dry for about 5 minutes.

[0048] S32, Apply sealing film 5 (e.g.) Figure 6 As shown): Apply a sealing film 5 to the outer surface of the non-repair area of ​​the lampshade (the back of the polished area) for protection. Use a scraper to slowly scrape and press from the center of the repair area outwards to remove air between the sealing film and the lampshade surface, ensuring a tight seal without bubbles or wrinkles. If the damaged area at L2 is larger than 10mm x 2mm and the lampshade surface is not a perfectly flat surface, the soft texture of the sealing film may prevent perfect shaping. In this case, apply a layer of approximately 1mm thick aluminum foil tape to the back of the sealing film to complete the shaping, avoiding secondary resin filling.

[0049] S4, dispensing and curing (e.g.) Figure 7 As shown in the figure): a light-curing resin was selected as the repair resin.

[0050] S42. Preheating and stress relief: Before applying the adhesive, place the lampshade in a constant temperature chamber and heat it to 80°C for 5 minutes. Then remove it and allow it to cool naturally to room temperature.

[0051] S43. Staged adhesive application and curing: Using a syringe, slowly inject the UV-cured resin into one end of the channel 3, allowing the resin to flow naturally under capillary action and gravity, covering and wetting the surface of the injection cavity 4, ensuring good wetting and initial bonding between the resin and the inner wall of the injection cavity 4. The injected amount accounts for 15% of the total repair resin. Use a 365nm ultraviolet lamp, 10-15cm away from the lamp cover surface, and irradiate for 60 seconds.

[0052] Using a syringe, slowly inject the remaining repair resin into the UV-cured resin (after subsequent injection, the resin should be slightly higher than the lampshade surface by 1-2 mm to ensure full filling). Similarly, slowly inject from one end of the guide channel 3 until the resin fills the entire injection cavity 4, especially the deeper parts of the feathering transition zone 1, ensuring the resin surface is slightly higher than the sealing film 5. Irradiate the entire cavity with a UV lamp for a sufficient duration of 10 minutes to ensure complete curing.

[0053] S5, Grinding (e.g.) Figure 8 (As shown): After the light-cured resin has fully cured, first remove the sealing film 5, and use a ball-head grinder to perform preliminary grinding on the repair area to remove the cured resin that protrudes above the lampshade surface.

[0054] S6, Surface treatment (such as...) Figure 9 (As shown): Use a polishing wheel and 3μm polishing compound to perform the first polishing on the polished area of ​​the lampshade, removing traces left by fine grinding. Then, use a fine-grained 1μm polishing compound for the second polishing until the surface of the repaired area achieves a mirror effect. After polishing, the original luster of the lampshade is restored. Finally, spray an anti-oxidation coating onto the lampshade. From a distance of 20-30cm from the lampshade surface, evenly spray a UV-curing coating and use a UV mercury lamp to cure and complete the surface hardening treatment of the lampshade.

[0055] Detection 1 (e.g.) Figure 10 As shown): Place the repaired lampshade from Example 2 into clean water. Visually inspect the repaired area so that it is not visible in the water. If it is visible, continue to fine-tune and polish until it meets the standard.

[0056] Detection 2 (e.g.) Figure 11 As shown): In terms of appearance inspection, under natural light conditions, visual observation was conducted at a distance of 50 cm from the lampshade. It was observed that the color of the repaired area was basically consistent with the surrounding original substrate, with no obvious color difference. The surface was smooth and flat, with no visible bubbles, damage, or obvious reflection marks remaining. The overall visual effect was close to that of an undamaged state.

[0057] Test 3: Reinstall the lamp cover back into the car headlight assembly in the reverse order of disassembly, and test the lighting effect. The light should have no shadows or obvious layering.

[0058] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for repairing damaged automotive lamp covers, characterized in that, S1. Disassemble and clean: Remove the damaged (6) lamp cover from the car lamp assembly and clean it; S2. Preparation of stepped repair matrix: Using a grinding device, a stepped grinding process is carried out with the damaged area (6) as the center, forming a composite structure of feathering transition zone (1), guide groove (3) and cicada wing zone (2) in sequence; S21. Forming a feathering transition zone (1): Taking the damage (6) as the center line, polish the areas on both sides to form a region with a smooth, concave surface and a depth and width that gradually change in all directions. S22. Opening a guide groove (3): At the bottom center of the feathering transition zone (1), completely remove the damaged material along the broken (6) path and grind to form a guide groove (3) with a uniform width. S23, Forming the cicada wing area (2): Finely thinning and polishing the two sides of the guide groove (3) to form a transparent thin layer area; S3. Cleaning and sealing the cavity (4): S31. Thoroughly remove all sanding residue; S32. On the inner side of the lampshade, in the area corresponding to the guide groove (3), a sealing film (5) is pasted to completely cover and seal the guide groove (3), thereby forming a glue injection cavity (4) together with the lampshade to accommodate the repair resin. S4. Adhesive application and curing: The repair resin is injected into the injection cavity (4) to allow it to penetrate and completely fill naturally; then, it is irradiated with an ultraviolet lamp to allow the repair resin to fully cure. S5. Grinding and leveling: Grind the raised parts of the cured repair resin to make its surface smoothly connect with the surrounding area; S6. Surface treatment: The ground and leveled area is then finished to make its appearance the same as or similar to the surrounding unrepaired lampshade surface.

2. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In step S21, the width of the feathering transition zone (1) is 10~60mm, the deepest point of its center is 50%~90% of the thickness of the lampshade substrate, and it smoothly transitions to the edge until it is flush with the original surface of the lampshade.

3. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In step S22, the width of the guide groove (3) is 1~30mm, and it penetrates the entire lampshade substrate.

4. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In step S23, the width of the cicada wing area (2) is 3~10mm, and its remaining thickness after polishing is no more than 0.3mm.

5. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, The criterion for judging whether the cicada wing area (2) is polished to a qualified standard is: when the lampshade is placed in clean water, the cicada wing area (2) is not visible in the water.

6. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In step S23, before polishing the cicada wing area (2), a pad that fits the lampshade is placed on the back of the polished surface of the lampshade.

7. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, After attaching the sealing film (5) in step S32, the edge of the cicada wing area (2) is finely polished to eliminate the step between the edge of the cicada wing area (2) and the sealing film (5).

8. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, S33. After step S2 is completed, a fence is bonded to the outer ring of the feathering transition zone (1) to prevent the repair resin injected into the feathering transition zone (1) from overflowing.

9. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In step S4, after the repair resin has fully cured, the sealing film and fence (5) are removed first, and then the grinding in step S5 is performed.

10. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In step S6, a polishing wheel and polishing paste are used to polish the polished areas of the lampshade to restore transparency.

11. The method for repairing damaged automotive lamp covers according to claim 10, characterized in that, After polishing, an anti-oxidation coating is sprayed onto the lampshade to complete the surface hardening treatment.

12. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In step S4, different repair resins are selected according to the size of the damaged area (6), and preheating and multi-stage curing are performed, specifically including: S41. Selection of Repair Resin: If the damage (6) is located on the edge of the lampshade and is accompanied by missing material, or if the damage (6) is located in a non-edge area of ​​the lampshade and is longer than 30mm, then transparent epoxy structural adhesive shall be used as the repair resin; if the damage (6) is in other parts of the lampshade, then light-cured resin shall be used as the repair resin. S42. Preheating and Stress Relief: Before applying the adhesive, place the lamp cover in a constant temperature chamber and heat it to 60℃~90℃ for 5~10 minutes, then remove it and let it cool naturally to room temperature. S43. Staged adhesive application and curing: The repair resin was injected into the injection cavity in multiple stages (4): The first injection is 10% to 30% of the total amount of repair resin, so that it initially covers and wets the surface of the injection cavity (4), and then light curing or static pre-curing is performed; Each time, the remaining repair resin is injected evenly to ensure complete filling of the injection cavity (4), and the resin is spread evenly by shaking the lampshade before final curing.

13. The method for repairing damaged automotive lamp covers according to claim 12, characterized in that, When using a transparent epoxy resin, in step S43: After the initial injection of the repair resin, allow it to stand at room temperature for 20-30 minutes to complete the initial curing. After injecting the remaining repair resin and spreading it evenly, let it stand to cure or move the lampshade into a constant temperature chamber and heat it at 60℃~90℃ for 10~15 minutes to cure, then take it out and cool it.

14. The method for repairing damaged automotive lamp covers according to claim 1, characterized in that, In S6, for colorless transparent lampshades, the finishing process is polishing and UV-cured coating reduction treatment; For colored transparent lampshades, the finishing process is a surface UV-cured coating reduction treatment.

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