A low-optical-distortion, spotless, large-curvature tempered glass and its forming method

Abstract

This invention relates to the field of new materials technology, specifically to a low-optical-distortion, spotless, large-curvature tempered glass and its forming method. The glass substrate includes a glass matrix with a preset curvature and a large projected area. The surface physical tempering stress value of the glass substrate is 90MPa~150MPa, and the stress difference between different areas of its surface is controlled within 5MPa. Under anisotropic observation conditions, the glass substrate has no visible stress marks on its surface, and its transmitted optical distortion intensity is no greater than 0.05 diopter, with reflection waviness controlled within a preset extremely low threshold. By precisely controlling the surface physical tempering stress value between 90MPa and 150MPa, and creatively controlling the stress difference between different areas of its surface within 5MPa, the stress gradient approaches zero. This extreme stress uniformity fundamentally eliminates the optical birefringence phenomenon caused by local stress abrupt changes, resulting in completely no visible stress marks on the glass under anisotropic observation conditions.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, specifically to a low-optical-distortion, spotless, large-curved tempered glass and its forming method. Background Technology

[0002] With the continuous upgrading of modern industrial design, large-curvature tempered glass is increasingly widely used in high-end smart cars (such as panoramic sunroofs and ultra-large curvature windshields), high-end building curtain walls, and large commercial display equipment. These applications place extremely stringent requirements on the optical performance and appearance quality of the glass, especially the tolerance for low optical distortion and stress spot-free core indicators, which is close to zero. In existing technologies, the production of large-curvature tempered glass typically involves three main processes: heating, mold pressing, and rapid cooling tempering of the air vents. However, due to the large size and complex variable curvature physical characteristics, existing production processes face insurmountable technical bottlenecks: First, optical distortion is difficult to eliminate. After glass reaches its softening point (typically above 600°C) in a furnace, the central area of ​​large-sized glass is prone to irregular sagging due to its own gravity. Simultaneously, the edges of large curved glass, with their larger heat dissipation area, experience a much faster temperature drop than the center. This imbalance in temperature gradient results in inconsistent plasticity across different parts of the glass when it enters the molding die. To force the glass into shape, current technologies often rely on high-strength mechanical mold closure. This rigid contact inevitably leaves tiny indentations and ripples on the softened glass surface. When light passes through these areas of localized surface deviation, severe transmission optical distortion—visual stretching or water ripples—occurs, significantly impacting driving safety and the viewing experience.

[0003] Secondly, there is the persistent problem of wind spots and stress spots in tempered glass. In the subsequent rapid cooling tempering stage, existing equipment often uses arrayed fixed air nozzles or simple reciprocating air grids to cool the glass. Due to the limitations of aerodynamics, the high-pressure cooling medium creates a stagnation point with zero airflow velocity directly below the air nozzle upon contact with the glass surface. The heat transfer coefficient in this stagnation area is extremely high, resulting in a much higher cooling rate than in non-stagnation areas. This uneven cooling rate directly leads to uneven permanent residual stress within the glass. Under natural light (especially polarized light), these uneven stress fields induce birefringence, resulting in visible colored or dark spots on the glass surface, commonly known in the industry as "wind spots" or "leopard spots."

[0004] Third, existing processes struggle to simultaneously improve both distortion and wind spots. Current technologies often fall into a "whack-a-mole" dilemma when attempting to address these issues. For example, increasing the nozzle oscillation amplitude or air pressure to eliminate wind spots can easily cause secondary deformation of the softened glass, exacerbating optical distortion. Conversely, increasing mold holding time to ensure surface accuracy can lead to missed optimal quenching opportunities, resulting in insufficient tempering stress or breakage. In summary, existing tempered glass forming technologies cannot fundamentally overcome the physical limitations of gravitational deformation, uneven thermal fields, and hydrodynamic stagnation effects, making it difficult to stably mass-produce large-curved tempered glass with both low optical distortion and spot-free characteristics. Therefore, a completely new product structure definition and forming process are urgently needed to overcome this common industry challenge. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a low-optical-distortion, spotless, large-curvature tempered glass and its forming method.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a low optical distortion spotless large curved tempered glass, comprising a glass substrate, wherein the glass substrate has a preset curvature and a large projected area; The surface physical tempering stress value of the glass substrate is 90MPa~150MPa, and the stress difference between different areas of its surface is controlled within 5MPa. Under anisotropic observation conditions, the glass substrate has no visible stress marks on its surface, and its transmission optical distortion intensity is no greater than 0.05 diopters, while the reflection waviness is controlled within a preset extremely low threshold.

[0007] Preferably, the stress distribution from the edge region to the center region of the glass substrate exhibits a continuous parabolic gradient transition; By controlling the consistency of the cooling rate, the stress variation gradient within any 50mm diameter area on the surface of the glass substrate approaches zero.

[0008] Preferably, the glass substrate has a single-curved, double-curved, or multi-curved surface structure, and the local surface shape deviation of its surface is no greater than 0.1mm / 1000mm. Furthermore, at the bending and turning parts of the glass, the deflection angle deviation of its transmitted light remains isotropic in all directions.

[0009] A method for forming a spotless large curved tempered glass with low optical distortion, S1. Matrix gradient heating: The glass sheet is placed in a heating furnace with independent control of multiple zones. According to the curvature model of the final forming, a non-uniform temperature field is applied to the glass surface to heat it, so that a preset temperature difference is formed between the center temperature zone and the edge temperature zone before the glass is put into the mold. S2. Dynamic follow-up forming: The heated glass is fed into the forming mold. During the mold closing process, the non-pressed area of ​​the glass is compensated for in real time by the flexible follow-up support component to suppress local sagging caused by the weight of the glass. S3. Multidimensional staggered quenching: The dynamic air grating with displacement adjustment function is used to rapidly cool the formed glass. By changing the relative motion trajectory between the air grating and the glass surface, the balance of airflow stagnation points is broken and stress spots are eliminated.

[0010] Preferably, in step S1: the heating furnace is divided into multiple temperature control units. By collecting thermal imaging data of the glass surface in real time, the heating power of each unit is dynamically adjusted to ensure that the surface temperature distribution of the glass sheet at the moment of exiting the furnace is positively correlated with the tensile deformation during subsequent bending and forming.

[0011] Preferably, in step S2: the flexible follow-up support component is controlled by a multi-axis servo system, and its motion trajectory is calculated and synchronized in real time according to the bending speed of the glass and the gravitational deformation modulus, ensuring that the direction of the support force vector is always perpendicular to the local sectional surface of the glass, thereby eliminating indentations and optical distortions caused by mechanical contact.

[0012] Preferably, in step S3: the air grid performs a compound oscillation action during the cooling process. The compound oscillation includes simple harmonic motion in the horizontal direction and micro-amplitude oscillation in the vertical direction, so that the spray trajectory of the cooling air nozzle on the glass surface forms a dense grid that does not overlap, so as to balance the heat transfer coefficient of the glass surface.

[0013] Preferably, step S3 further includes: dynamically adjusting the spray pressure and spray distance of each nozzle in the air grid according to the curvature changes of different parts of the glass, so that the cooling intensity of the deep curve at the center of the large curved glass is consistent with that of the straight edge, and ensuring the overall stress uniformity.

[0014] Preferably, it also includes: during the transition between the forming step and the quenching step, activating an edge heat compensation system to use infrared radiation to instantly reheat areas where the glass edge cools too quickly, with a temperature difference compensation range of 20℃~50℃, in order to prevent edge distortion and rainbow spots caused by edge pre-cooling.

[0015] Preferably, it also includes an online detection step, which uses a high-precision scanner to acquire stress distribution and optical distortion data of the cooled glass, and feeds the data back to the heating device and quenching device to realize the closed-loop automatic correction of subsequent product production parameters.

[0016] The beneficial effects of this invention are: (1) The present invention provides a low-optical-distortion, spotless large-curvature tempered glass and its forming method. The large-curvature tempered glass achieves this by precisely controlling the surface physical tempering stress value between 90MPa and 150MPa, and creatively controlling the stress difference between different areas of its surface within 5MPa, thereby making the stress gradient approach zero. This extreme stress uniformity fundamentally eliminates the optical birefringence phenomenon caused by local stress abrupt changes, making the glass completely free of stress marks visible to the naked eye under anisotropic observation conditions.

[0017] (2) The low-optical-distortion, spotless large-curved tempered glass and its forming method described in this invention employ matrix gradient heating combined with edge thermal compensation during the heating stage to preemptively offset edge heat loss during glass forming, ensuring consistent plasticity across the entire surface. During the forming stage, a breakthrough is achieved by introducing flexible, servo-driven support components, ensuring the support vector force is perpendicular to the glass cut surface in real time, eliminating gravity-induced sagging while avoiding mechanical rigid indentation. During the quenching stage, a multi-dimensional, staggered quenching composite oscillating air grid is used, completely breaking the cooling stagnation effect caused by traditional fixed air nozzles, forming a uniform heat exchange grid on the glass surface. This combination of gradient thermal field, servo-driven forming, and grid quenching upgrades traditional passive pressing to active stress field management, significantly improving the mass production consistency of large-size complex curved glass. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 The overall flowchart of a method for forming a spotless large curved tempered glass with low optical distortion provided by the present invention; Figure 2 The process, detection, and feedback closed-loop flowchart provided by this invention; Figure 3 A flowchart showing the correspondence between key product features and processes provided by this invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0021] like Figures 1-3 As shown, the present invention provides a low-optical-distortion, spotless, large-curvature tempered glass, comprising a glass substrate having a preset curvature and a large projected area. The surface physical tempering stress value of the glass substrate is 90MPa~150MPa, and the stress difference between different areas of its surface is controlled within 5MPa. Under anisotropic observation conditions, the glass substrate has no visible stress marks on its surface, and its transmitted optical distortion intensity is no greater than 0.05 diopters, while the reflection waviness is controlled within a preset extremely low threshold.

[0022] By controlling the curvature and large projected area of ​​the glass substrate, the requirements for large curved surface applications are met. Simultaneously, the surface physical tempering stress is controlled within a reasonable range of 90MPa to 150MPa, ensuring the glass's tempering strength to resist impact and breakage while avoiding glass embrittlement or stress distortion caused by excessive stress. The stress difference between different areas of the surface is strictly controlled to ≤5MPa, ensuring uniform stress distribution on the glass surface and preventing stress spots caused by localized stress concentration. Through optimized tempering processes, no visible stress spots are observed under anisotropic conditions, while the transmission optical distortion intensity is controlled to ≤0.05 diopter, and the reflection waviness is controlled at an extremely low threshold, reducing light shift and distortion during transmission and reflection, achieving a low optical distortion effect.

[0023] The reasonable tempering stress range and extremely small stress difference give the glass both high strength and toughness, making it difficult to break. When broken, it forms small, obtuse-angled particles, ensuring high safety. It also boasts excellent optical performance: no visible stress spots, low transmission optical distortion, and low reflection waviness, meeting the requirements of high-end optical applications such as automotive curved glass, high-end architectural curved curtain walls, and precision instrument protective glass for light transmission and image clarity. Furthermore, it is adaptable to large curved surface needs: with preset curvature and large projected area, it can be customized according to actual application scenarios, adapting to various large curved surface equipment or architectural requirements, making it highly practical.

[0024] The low-optical-distortion, spotless, large-curved tempered glass has a single-curved surface structure with a curvature of R500mm and a projected area of ​​1200mm×800mm. A physical tempering process is employed, controlling the physical tempering stress value on the glass substrate surface to 120MPa. Through zoned temperature-controlled tempering, the stress difference between the center, edge, and curved transition areas of the surface is reduced to 3MPa. When observed under an anisotropic instrument, no visible stress marks are found on the surface. An optical distortion tester shows a transmitted optical distortion intensity of 0.03 diopter. A waviness tester shows a reflected waviness of 0.02μm, lower than the preset minimum threshold of 0.05μm. This glass is used for protecting curved screens in automotive center consoles, providing clear, distortion-free light transmission without stress marks affecting the appearance, while also withstanding daily impacts and meeting safety standards.

[0025] As a preferred technical solution, the stress distribution from the edge region to the center region of the glass substrate exhibits a continuous parabolic gradient transition. By controlling the consistency of the cooling rate, the stress variation gradient within any 50mm diameter area on the glass substrate surface is made close to zero.

[0026] The stress distribution from the edge region to the center region of the glass substrate exhibits a continuous parabolic gradient transition, avoiding abrupt stress changes at the edge and center, and reducing glass breakage or optical distortion caused by stress concentration. By precisely controlling the uniformity of the cooling rate during the tempering process, the stress change gradient within any 50mm diameter area on the glass substrate surface approaches zero, ensuring uniform stress in local areas, fundamentally suppressing the generation of stress spots, and further improving the optical distortion control effect.

[0027] The parabolic gradient stress distribution eliminates abrupt stress changes between the edges and the center, reducing the risk of glass breakage due to stress concentration and improving product qualification rate. The stress change gradient within any small area with a diameter of 50mm approaches zero, avoiding local optical distortion caused by uneven local stress and further improving the overall optical consistency of the glass. It can meet the needs of scenarios with extremely high requirements for optical uniformity, such as high-end automotive head-up display glass and precision optical instrument windows, thus broadening the product's application range.

[0028] As a preferred technical solution, the glass substrate has a single-curved, double-curved, or multi-curved surface structure, and the local surface shape deviation of its surface is no greater than 0.1mm / 1000mm. Furthermore, at the bending and turning parts of the glass, the deflection angle deviation of its transmitted light remains isotropic in all directions.

[0029] The glass substrate can adopt a single-curved, double-curved, or multi-curved surface structure to adapt to the surface requirements of different application scenarios. Through precision forming process, the local surface shape deviation of the glass is controlled to be ≤0.1mm / 1000mm, ensuring the surface accuracy and avoiding light refraction and reflection distortion caused by surface shape deviation. For the bending and turning parts of the glass, the forming and tempering processes are optimized to keep the deflection angle deviation of transmitted light isotropic in all directions, ensuring the stable propagation direction of light at the turning parts and further reducing optical distortion.

[0030] A method for forming a spotless large curved tempered glass with low optical distortion, S1. Matrix gradient heating: The glass sheet is placed in a heating furnace with independent control of multiple zones. According to the curvature model of the final forming, a non-uniform temperature field is applied to the glass surface to heat it, so that a preset temperature difference is formed between the center temperature zone and the edge temperature zone before the glass is put into the mold. S2. Dynamic follow-up forming: The heated glass is fed into the forming mold. During the mold closing process, the non-pressed area of ​​the glass is compensated for in real time by the flexible follow-up support component to suppress local sagging caused by the weight of the glass. S3. Multidimensional staggered quenching: The dynamic air grating with displacement adjustment function is used to rapidly cool the formed glass. By changing the relative motion trajectory between the air grating and the glass surface, the balance of airflow stagnation points is broken and stress spots are eliminated.

[0031] Matrix gradient heating: Based on the curvature model of the final glass forming, a multi-zone independently controlled heating furnace is used to implement a non-uniform temperature field heating on the glass surface, so that a preset temperature difference is formed between the center and the edge of the glass before it enters the mold, providing a reasonable temperature gradient for subsequent bending and forming, and avoiding surface deviation and stress unevenness caused by uneven temperature during forming; Dynamic follow-up forming: After the heated glass is sent into the forming mold, the displacement of the non-pressed area of ​​the glass is compensated in real time by a flexible follow-up support component, suppressing local sagging caused by the weight of the glass and ensuring the accuracy of the formed surface; Multi-dimensional staggered quenching: The glass after forming is rapidly cooled by a displacement-adjustable dynamic air grid. By changing the relative motion trajectory between the air grid and the glass surface, the balance of airflow stagnation points is broken, avoiding stress spots caused by uneven local cooling, while ensuring tempering strength.

[0032] High forming precision: Gradient heating matches curvature requirements, and dynamic follow-up support suppresses self-weight sagging, effectively controlling surface deviation and optical distortion to ensure the forming quality of large curved surfaces; No stress spot generation: Multi-dimensional staggered quenching breaks airflow stagnation points, ensuring uniform cooling and eliminating stress spots from the process, thus improving the optical performance and appearance quality of the glass; Strong process stability: Three-step coordinated control allows for precise adjustment of each stage, adapting to the preparation of large curved glass with different curvatures and sizes, resulting in high production efficiency and a high product qualification rate.

[0033] S1. Matrix Gradient Heating: A 5mm thick glass sheet is placed in a heating furnace with 24 independent temperature control units. Based on the hyperboloid curvature model with a major axis of R600mm and a minor axis of R400mm, the temperature of the center zone is set to 680℃ and the temperature of the edge zone is set to 650℃, forming a preset temperature difference of 30℃. Through real-time temperature control, the temperature distribution when the glass exits the furnace is ensured to match the subsequent stretching deformation. S2. Dynamic Follow-up Forming: The heated glass is sent into the hyperboloid forming mold. During the mold closing process, the flexible follow-up support component consists of 8 sets of flexible support heads. Through real-time displacement detection, displacement compensation is performed on the non-pressed area of ​​the glass with a compensation accuracy of 0.01mm, suppressing local sagging caused by the glass's own weight, and controlling the sagging amount within 0.05mm. S3. Multidimensional staggered quenching: A dynamic air grating with adjustable displacement is used. The air grating speed is 25 m / s. By reciprocating horizontally at a frequency of 10 times / minute and slightly raising and lowering vertically by 5 mm, the relative motion trajectory between the air grating and the glass surface is changed, breaking the airflow stagnation balance. The cooling time is 80 s. The formed glass is tested and found to have a surface deviation of 0.07 mm / 1000 mm, no visible stress spots, and a transmitted optical distortion intensity of 0.025 diopter, meeting all the indicators of claim 3.

[0034] As a preferred technical solution, in step S1: the heating furnace is divided into multiple temperature control units. By collecting thermal imaging data of the glass surface in real time, the heating power of each unit is dynamically adjusted to ensure that the surface temperature distribution of the glass sheet at the moment of exiting the furnace is positively correlated with the tensile deformation during subsequent bending and forming.

[0035] The heating furnace is divided into multiple temperature control units. Thermal imaging data of the glass surface is collected in real time by thermal imaging equipment. The heating power of each temperature control unit is dynamically adjusted according to the data. This ensures that the surface temperature distribution of the glass sheet at the moment it leaves the furnace is positively correlated with the tensile deformation during subsequent bending and forming. That is, the temperature is slightly higher in areas with large tensile deformation, such as parts with large curvature of the surface, and slightly lower in areas with small tensile deformation, such as parts with small curvature of the surface. This ensures that the glass is subjected to uniform stress during the forming process and avoids surface deviation and uneven stress caused by the mismatch between temperature and tensile deformation.

[0036] Higher heating precision: Multiple temperature control units are independently adjustable, combined with real-time thermal imaging feedback, to precisely control the temperature distribution on the glass surface, avoiding localized overheating or undercooling; Better forming consistency: Temperature distribution is positively correlated with tensile deformation, ensuring uniform stress during glass forming, reducing surface deviation and internal stress, and improving product consistency; Reduced forming defects: Avoids defects such as cracking and warping during glass forming caused by uneven temperature, further improving the production pass rate; Adaptable to complex curved surfaces: Can precisely match the tensile deformation of different parts for complex structures such as hyperboloids and multi-curved surfaces, ensuring the forming quality of complex curved surfaces.

[0037] As a preferred technical solution, in step S2: the flexible follow-up support component is controlled by a multi-axis servo system, and its motion trajectory is calculated and synchronized in real time according to the bending speed of the glass and the gravitational deformation modulus, so as to ensure that the direction of the support force vector is always perpendicular to the local sectional surface of the glass, thereby eliminating indentations and optical distortions caused by mechanical contact.

[0038] The flexible follow-up support component is controlled by a multi-axis servo system, which collects the bending speed and gravitational deformation modulus of the glass in real time. Based on the collected data, the motion trajectory of the support component is calculated in real time and synchronized with the bending motion of the glass. This ensures that the direction of the support force vector is always perpendicular to the local cross-section of the glass, that is, the support force is perpendicular to the local surface of the glass. This avoids mechanical contact indentation caused by deviation of the support force direction, while suppressing local sagging caused by the weight of the glass itself, ensuring the accuracy of the formed surface, and reducing optical distortion caused by mechanical contact.

[0039] Avoid mechanical damage: The support force direction is always perpendicular to the local cut surface of the glass, eliminating indentations and scratches caused by mechanical contact and ensuring the integrity of the glass surface; Improve surface accuracy: The support trajectory is synchronized with the glass bending movement, effectively suppressing self-weight sagging, further reducing surface deviation, and improving molding quality; Reduce optical distortion: Avoid optical distortion caused by indentations and local deformation, ensuring stable optical performance of the glass; Adapt to different bending speeds: The multi-axis servo system can adjust the motion trajectory in real time to adapt to the molding requirements of different bending speeds, improving process flexibility.

[0040] The flexible follow-up support assembly is controlled by a 6-axis servo system, equipped with speed and deformation sensors, to collect real-time data on the glass's bending speed (0.5–0.8 mm / s) and gravitational deformation modulus (2.8 × 10⁻⁶). 5 The system operates at MPa and calculates the motion trajectory of the support components in real time based on the collected data. The synchronization error between the motion trajectory and the glass bending motion is ≤0.005s. It ensures that the direction of the support force vector is always perpendicular to the local cross-section of the glass, with a perpendicularity error of ≤0.1°. After molding, the glass surface is inspected under a high-magnification microscope, and no mechanical indentations or scratches are found. The surface deviation is controlled within 0.05mm / 1000mm, and the optical distortion intensity is further reduced to 0.02 diopter, fully meeting the requirements of high-end optical applications.

[0041] As a preferred technical solution, in step S3: the air grid performs a compound oscillation action during the cooling process. The compound oscillation includes simple harmonic motion in the horizontal direction and micro-oscillation in the vertical direction, so that the spray trajectory of the cooling air nozzle on the glass surface forms a dense grid that does not overlap, so as to balance the heat transfer coefficient of the glass surface.

[0042] During the cooling process, the air grille performs a compound oscillation action, which includes simple harmonic motion in the horizontal direction (reciprocating oscillation) and micro-oscillation in the vertical direction (up and down). This causes the spray trajectory of the cooling air nozzles on the glass surface to form a dense grid coverage that does not overlap. In other words, each area can be evenly sprayed by the cooling air without any dead spots. This balances the heat transfer coefficient of the glass surface, avoids local cooling that is too fast or too slow, further eliminates stress spots, and ensures uniform stress distribution.

[0043] More uniform cooling: The dense grid-like spray trajectory eliminates spray dead zones, balances the heat transfer coefficient of the glass surface, and avoids uneven cooling in certain areas; Complete elimination of stress spots: Improved cooling uniformity fundamentally eliminates the generation of stress spots, enhancing the appearance and optical performance of the glass; More uniform stress distribution: The balanced heat transfer coefficient ensures consistent cooling rates across all parts of the glass, resulting in more uniform stress distribution and reducing stress differences; Adaptable to large curved surfaces: The composite oscillating motion can adapt to the cooling needs of large-size, complex curved glass surfaces, ensuring uniform cooling across all parts of the curved surface.

[0044] The air grating performs a compound oscillation motion. The horizontal simple harmonic motion has a frequency of 15 times / minute and an amplitude of 100mm; the vertical micro-oscillation has a frequency of 20 times / minute and an amplitude of 8mm. The cooling air nozzles have a spray orifice diameter of 0.5mm and a spray spacing of 10mm. Through the compound oscillation, the spray trajectory forms a dense grid with a spacing of 5mm, completely covering the glass surface without any spray dead zones. The heat transfer coefficient of the glass surface was measured, and the deviation of the heat transfer coefficient in each area was ≤0.5W / (m²·K). After cooling, the glass was observed anisotropically, showing no visible stress spots, a stress difference reduced to 2MPa, and a reflection waviness of 0.015μm.

[0045] As a preferred technical solution, step S3 further includes: dynamically adjusting the spray pressure and spray distance of each nozzle in the air grid according to the curvature changes of different parts of the glass, so that the cooling intensity of the deep curve at the center of the large curved glass is consistent with that of the straight edge, and ensuring the overall stress uniformity.

[0046] Based on the curvature variations of different parts of the glass (e.g., greater curvature at the center of the deep curve and less curvature at the straight edges), the spray pressure and distance of each nozzle in the air grid are dynamically adjusted. At the center of the deep curve, where curvature is greater, the nozzle spray pressure is slightly higher and the spray distance is slightly shorter to ensure cooling intensity. At the edge of the straight curve, where curvature is less, the nozzle spray pressure is slightly lower and the spray distance is slightly longer to avoid over-cooling. This ensures consistent cooling intensity across all parts of the large curved glass, guarantees overall stress uniformity, and further reduces optical distortion.

[0047] High adaptability to cooling intensity: The spray parameters are dynamically adjusted according to the curvature changes to ensure consistent cooling intensity across all parts of the curved surface, avoiding local over- or under-cooling; Further improvement in stress uniformity: Consistent cooling intensity ensures uniform stress distribution across all parts of the glass, further reducing stress differences and minimizing stress distortion; Adaptability to complex large curved surfaces: Precise control can be applied to different curvature areas such as deep bends in the center and straight edges, adapting to the quenching requirements of various large curved glass surfaces; Enhanced optical performance: Improved stress uniformity further reduces optical distortion, ensuring stable light transmission and reflection performance of the glass.

[0048] As a preferred technical solution, it also includes: in the transition stage between the forming step and the quenching step, activating an edge heat compensation system, using infrared radiation to instantly replenish the heat of the glass edge area that cools too quickly, with a temperature difference compensation range of 20℃~50℃, to prevent edge distortion and rainbow spots caused by edge pre-cooling.

[0049] Because the glass edges are relatively thinner or dissipate heat faster, the cooling rate of the edge area is faster than that of the center area during the molding and quenching process, which can easily lead to edge distortion and rainbow spots. By using an edge thermal compensation system, infrared radiation is used to instantly reheat the glass edge areas that cool too quickly. The temperature difference for reheating is controlled between 20℃ and 50℃ to compensate for the temperature difference between the edge and the center, avoid stress concentration and optical defects caused by edge pre-cooling, and ensure the overall optical performance and appearance quality of the glass.

[0050] Eliminate edge distortion and rainbow spots: By using edge thermal compensation, the cooling rate between the edge and the center is balanced, avoiding distortion and rainbow spots caused by edge pre-cooling, thus improving the appearance quality of the glass; Improve edge mechanical properties: Avoid edge stress concentration, improve the toughness and strength of the glass edge, and reduce the risk of edge breakage; Ensure overall optical consistency: Balance the temperature difference between the edge and the center, making the stress distribution more uniform, ensuring consistent overall optical performance of the glass without local deviations.

[0051] As a preferred technical solution, it also includes: an online detection step, which uses a high-precision scanner to acquire stress distribution and optical distortion data of the cooled glass, and feeds the data back to the heating device and quenching device to realize the closed-loop automatic correction of subsequent product production parameters.

[0052] After the glass has cooled, its stress distribution and optical distortion data are acquired by a high-precision scanner. The data is compared with preset standard values, such as stress difference ≤ 5MPa and transmission optical distortion ≤ 0.05 diopter. If the data exceeds the standard value, the deviation data is fed back to the heating device S1 and the quenching device S3. The device automatically adjusts relevant parameters such as heating power, cooling wind speed, and jet pressure to form a closed loop of detection, feedback, and correction. This enables automatic correction of subsequent product production parameters and ensures the stability and consistency of product quality.

[0053] Achieve automated quality control: Real-time online detection and feedback automatically correct production parameters without manual intervention, improving production efficiency; Stable product quality: Closed-loop correction ensures that stress distribution and optical distortion of subsequent products always meet standards, reducing product quality fluctuations; Reduced labor costs: Reduced workload of manual inspection and parameter adjustment, reducing human error; Facilitates process optimization: By accumulating test data, process parameters such as heating and quenching can be further optimized, continuously improving product performance.

[0054] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A type of low-optical-distortion, spotless, large-curved tempered glass, characterized in that: Includes a glass substrate, wherein the glass substrate has a preset curvature and a large projected area; The surface physical tempering stress value of the glass substrate is 90MPa~150MPa, and the stress difference between different areas of its surface is controlled within 5MPa. Under anisotropic observation conditions, the glass substrate has no visible stress marks on its surface, and its transmission optical distortion intensity is no greater than 0.05 diopters, while the reflection waviness is controlled within a preset extremely low threshold.

2. The low optical distortion, spotless, large-curved tempered glass according to claim 1, characterized in that: The stress distribution from the edge region to the center region of the glass substrate exhibits a continuous parabolic gradient transition. By controlling the consistency of the cooling rate, the stress variation gradient within any 50mm diameter area on the surface of the glass substrate approaches zero.

3. The low optical distortion, spotless, large-curved tempered glass according to claim 2, characterized in that: The glass substrate has a single-curved, double-curved, or multi-curved surface structure, and the local surface shape deviation of its surface is no greater than 0.1mm / 1000mm. Furthermore, at the bending and turning parts of the glass, the deflection angle deviation of its transmitted light remains isotropic in all directions.

4. A method for forming low-optical-distortion, spotless, large-curvature tempered glass as described in any one of claims 1 to 3, characterized in that: S1. Matrix gradient heating: The glass sheet is placed in a heating furnace with independent control of multiple zones. According to the curvature model of the final shape, a non-uniform temperature field is applied to the glass surface to heat it, so that a preset temperature difference is formed between the center temperature zone and the edge temperature zone before the glass is put into the mold. S2. Dynamic follow-up forming: The heated glass is fed into the forming mold. During the mold closing process, the non-pressed area of ​​the glass is compensated for in real time by the flexible follow-up support component to suppress local sagging caused by the weight of the glass. S3. Multidimensional staggered quenching: The dynamic air grating with displacement adjustment function is used to rapidly cool the formed glass. By changing the relative motion trajectory between the air grating and the glass surface, the balance of airflow stagnation points is broken and stress spots are eliminated.

5. The method for forming low-optical-distortion, spotless, large-curved tempered glass according to claim 4, characterized in that: In step S1: The heating furnace is divided into multiple temperature control units. By collecting thermal imaging data of the glass surface in real time, the heating power of each unit is dynamically adjusted to ensure that the surface temperature distribution of the glass sheet at the moment of exiting the furnace is positively correlated with the tensile deformation during subsequent bending and forming.

6. The method for forming low-optical-distortion, spotless, large-curved tempered glass according to claim 4, characterized in that: In step S2: The flexible follow-up support component is controlled by a multi-axis servo system. Its motion trajectory is calculated and synchronized in real time according to the bending speed of the glass and the gravitational deformation modulus, ensuring that the direction of the support force vector is always perpendicular to the local sectional surface of the glass, thereby eliminating indentations and optical distortions caused by mechanical contact.

7. The method for forming low-optical-distortion, spotless, large-curved tempered glass according to claim 6, characterized in that: In step S3: the air grid performs a compound oscillation action during the cooling process. The compound oscillation includes simple harmonic motion in the horizontal direction and micro-amplitude oscillation in the vertical direction, so that the spray trajectory of the cooling air nozzle on the glass surface forms a dense grid that does not overlap, so as to balance the heat transfer coefficient of the glass surface.

8. The method for forming low-optical-distortion, spotless, large-curvature tempered glass according to claim 7, characterized in that: Step S3 further includes: dynamically adjusting the spray pressure and spray distance of each nozzle in the air grid according to the curvature changes of different parts of the glass, so that the cooling intensity of the deep curve at the center of the large curved glass is consistent with that of the straight edge, and ensuring the overall stress uniformity.

9. The method for forming low-optical-distortion, spotless, large-curved tempered glass according to claim 4, characterized in that: Also includes: During the transition between the forming and quenching steps, an edge heat compensation system is activated. Infrared radiation is used to instantly reheat areas where the glass edge cools too quickly, compensating for temperature differences ranging from 20°C to 50°C, in order to prevent edge distortion and rainbow spots caused by edge pre-cooling.

10. The method for forming low-optical-distortion, spotless, large-curvature tempered glass according to claim 4, characterized in that: Also includes: The online inspection process uses a high-precision scanner to acquire stress distribution and optical distortion data of the cooled glass, and feeds the data back to the heating and quenching devices to achieve automatic closed-loop correction of subsequent product production parameters.

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