A deformation compensation design method for an automotive light guide bar

Abstract

The present invention relates to the technical field of automotive headlight design and manufacturing. Specifically, it relates to a deformation compensation design method for an automotive light guide bar. The method includes: Step S1, establishing a product model of the light guide bar; Step S2, performing mold flow analysis on the product model of the light guide bar to obtain model deformation data; Step S3, establishing an optical model of the light guide bar based on the model deformation data; Step S4, simulating the optical model of the light guide bar to obtain a light efficiency defect area; Step S5, obtaining a model compensation amount based on the light efficiency defect area and generating an output model based on the model compensation amount. This method constructs a closed-loop feedback mechanism for deformation and light efficiency by coupling mold flow analysis and optical simulation, solves the problem of geometric deformation and optical performance mismatch of the light guide bar caused by material shrinkage in traditional technologies, and effectively reduces production costs and development cycles.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive headlamp design and manufacturing, and more particularly, to a method for deformation compensation design of an automotive light guide bar. Background Art

[0002] In the field of automotive headlamp design and manufacturing, a light guide bar is a core optical component for achieving uniform illumination and dynamic light effects. It is usually made of transparent plastic material through an injection molding process, with micron-level prisms or scattering texture structures distributed on its surface, guiding the propagation of light through the principle of total internal reflection.

[0003] However, the geometric deformation problem caused by the shrinkage characteristics of plastic materials during the injection molding process has long restricted the optical performance and production efficiency of products. In the prior art, the dimensional deviation caused by anisotropic shrinkage rate during the material cooling stage will significantly change the light propagation path, resulting in dark area or bright spot defects with a local light intensity difference exceeding 30%. The industry generally relies on empirical formula pre-compensation and trial-and-error method correction, but due to the lack of consideration of regional shrinkage differences, multiple mold trials are often required to meet the light effect requirements. At the same time, the problem of data fragmentation between mold flow analysis and optical simulation tools is prominent. The macroscopic deformation amount predicted by mold flow analysis is not correlated with the deformation of the microscopic optical structure, resulting in the disconnection between compensation design and actual light effect verification. Summary of the Invention

[0004] The problem solved by the present invention is that in the design and production of automotive light guide bars, mold flow analysis and optical simulation operate independently, resulting in the deformation prediction not covering the optically sensitive areas and the disconnection between the mold flow analysis compensation design and the actual light effect requirements.

[0005] The present invention adopts the following technical solutions: A method for deformation compensation design of an automotive light guide bar, the deformation compensation design method comprising:

[0006] Step S1, establishing a light guide bar product model;

[0007] Step S2, performing mold flow analysis on the light guide bar product model to obtain model deformation data;

[0008] Step S3, establishing a light guide bar optical model based on the model deformation data;

[0009] Step S4, simulating the light guide bar optical model to obtain the light effect defect area;

[0010] Step S5, obtaining a model compensation amount based on the light effect defect area and generating an output model based on the model compensation amount.

[0011] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: First, by directly mapping the microscopic structure deformation data obtained from mold flow analysis to the optical model, the limitation of the separation of mold flow and light effect simulation data in the traditional method is broken through, enabling the compensation design to accurately correlate geometric deformation with light intensity distribution; Second, based on optical simulation to locate the light effect defect area, it replaces the traditional method of relying on manual experience to judge the defect position, avoids the extension of the production cycle caused by ineffective compensation, and reduces the production cost.

[0012] Further, step S5 further includes detecting whether the output model meets the standard. If it does not meet the standard, the light guide bar product model is reconstructed according to the output model, and then the process returns to step S2.

[0013] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: First, through closed-loop feedback optimization design and iterative updating of the light guide bar product model, the geometric compensation amount gradually approaches the theoretical optimal value, avoiding the low efficiency problem caused by repeatedly modifying the mold in the traditional trial-and-error method, and improving the design accuracy and reliability; Second, it replaces the traditional way of manually adjusting product parameters, and greatly reduces the time spent on correcting compensation parameters.

[0014] Further, step S2 further includes: performing mold flow analysis on the light guide bar product model based on material parameters and process parameters.

[0015] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: By combining material and process parameters for simulation, accurately predicting the deformation trend in actual molding, reducing the prediction deviation caused by insufficient experience. At the same time, defects caused by process parameter mismatch are predicted and avoided at the mold flow stage, reducing the cost of trial molding.

[0016] Further, when performing mold flow analysis on the light guide bar product model based on material parameters and process parameters, the mold surface temperature and the melt temperature are selected to determine the molding data of the light guide bar product model.

[0017] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: By combining the interaction between the melt temperature and the mold surface temperature, accurately simulating the phase change process of the material from the molten state to the solid state, greatly reducing the prediction error of shrinkage deformation.

[0018] Further, when performing mold flow analysis on the light guide bar product model based on material parameters and process parameters, it also includes selecting the injection time, holding pressure time, and holding pressure to determine the melt filling data.

[0019] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: First, through the matching and optimization of the injection time and the holding pressure, the uniformity of the melt flow front velocity is improved, avoiding the short-shot or gas cavity defects caused by uneven filling; Second, by coupling the holding time and the holding pressure, the melt cooling shrinkage is effectively compensated, and the volume shrinkage rate of the light guide bar is effectively increased compared with the traditional method; Third, through the collaborative analysis of multiple parameters, the injection molding process is comprehensively simulated, the molding quality is optimized, and the limitations of single-parameter analysis are avoided.

[0020] Further, the material parameters also include the material PVT curve and the material thermal performance parameters, which are used for mold flow analysis of the light guide bar product model.

[0021] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: First, based on the PVT curve, the volume change of the material during the melting-cooling phase change is quantified, reducing the shrinkage rate prediction error; Second, by combining the material thermal conductivity and the mold cooling rate, the influence of the local temperature gradient on the microstructure forming is predicted; Third, for different materials, the mold flow analysis parameters are dynamically adjusted, reducing the matching error of the shrinkage compensation amounts of the two materials under the same process and reducing the over-compensation rate.

[0022] Further, step S2 also includes: establishing an optical model of the light guide bar according to the refractive index and the surface scattering coefficient.

[0023] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: First, the light path offset of the deformed light guide bar is quantified through the refractive index, and the surface microstructure defects are evaluated by combining the scattering coefficient, reducing the light intensity uniformity prediction error; Second, based on the optical parameter mapping, the recognition accuracy of the light effect defect area is improved, the compensation area is reduced, and the waste of resources caused by ineffective compensation is avoided; Third, the influence of the deformation on the light effect is quantified through the optical parameter modeling, replacing the traditional compensation method that only depends on geometric deformation, and improving the pertinence of the light effect repair.

[0024] Further, in step S3, the optical model of the light guide bar is preprocessed, and the preprocessing includes setting the target optical parameters of the optical model of the light guide bar.

[0025] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: The light effect design target is clarified, providing a benchmark for the calculation of the compensation amount and avoiding the deviation of the compensation direction from the actual requirements.

[0026] Further, step S5 also includes: obtaining the deformed light guide parameters according to the model deformation data, and obtaining the model compensation amount according to the deformed light guide parameters. The model compensation amount is:

[0027] = +k·( - ));

[0028] Among them, is the light guiding parameter after deformation, is the target optical parameter, is the compensation parameter, and k is the material-structure coefficient.

[0029] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: First, by coupling the geometric deformation and optical performance through the k value, the repair efficiency of light intensity uniformity is improved. Second, for the deformation and non-linear response of light intensity loss in the curved surface area of the light guide bar, through mathematical model fitting, the compensation accuracy is improved.

[0030] Furthermore, the material-structure coefficient is selected through the light flux loss rate. The calculation formula for the light flux loss rate is: (initial design light flux - measured light flux) / initial design light flux × 100%, where the initial design light flux is the target light flux, and the measured light flux is obtained by actually measuring the output model.

[0031] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: First, according to the measured light flux loss rate, the production cost is reduced and over-compensation is reduced. Second, for the performance fluctuations of different batches of the same material, by controlling the k value, the light flux consistency of the light guide bar is improved. Third, based on the measured light flux, the compensation coefficient is dynamically optimized to solve the problem that the traditional fixed compensation coefficient cannot adapt to different materials and structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 shows a flowchart of a method for compensating deformation design of an automotive light guide bar in this exemplary embodiment;

[0033] Figure 2 shows a structural schematic diagram of an automotive light guide bar in this exemplary embodiment;

[0034] Figure 3 shows a deformation schematic diagram of an automotive light guide bar in the X direction in mold flow analysis in this exemplary embodiment;

[0035] Figure 4 shows a deformation schematic diagram of an automotive light guide bar in the Y direction in mold flow analysis in this exemplary embodiment;

[0036] Figure 5 shows a deformation schematic diagram of an automotive light guide bar in the Z direction in mold flow analysis in this exemplary embodiment;

[0037] Figure 6 shows a deformed structural schematic diagram of an automotive light guide bar after mold flow analysis in this exemplary embodiment;

[0038] Figure 7Schematic diagram showing a structure for compensating and adjusting a light guide bar in a vehicle according to this exemplary embodiment;

[0039] Figure 8 Diagram comparing the lighting effects of a vehicle light guide bar before and after deformation in this exemplary embodiment;

[0040] Figure 9 Diagram showing the deformation-light intensity loss response surface of a vehicle light guide bar in this exemplary embodiment. Detailed implementation manners

[0041] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present disclosure. However, those skilled in the art will realize that the technical solutions of the present disclosure can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring the various aspects of the present disclosure.

[0042] In addition, the flowcharts shown in the accompanying drawings are only illustrative and not necessarily include all steps. For example, some steps may be decomposed, while some steps may be combined or partially combined, so the actual execution order may change according to the actual situation.

[0043] Refer to Figures 1-8 , this embodiment adopts the following technical solution: A deformation compensation design method includes:

[0044] Step S1, establish a light guide bar product model;

[0045] Step S2, perform mold flow analysis on the light guide bar product model to obtain model deformation data;

[0046] Step S3, establish a light guide bar optical model based on the model deformation data;

[0047] Step S4, simulate the light guide bar optical model to obtain the light effect defect area;

[0048] Step S5, obtain the model compensation amount based on the light effect defect area, and generate an output model based on the model compensation amount.

[0049] First, by directly mapping the microstructure deformation data obtained from mold flow analysis to the optical model, the limitation of the separation of mold flow and light effect simulation data in traditional methods is broken through, enabling the compensation design to accurately correlate geometric deformation with light intensity distribution. Second, based on optical simulation to locate the light effect defect area, it replaces the traditional way of relying on manual experience to judge the defect position, avoids the elongation of the production cycle caused by ineffective compensation, and reduces the production cost.

[0050] Specifically, referring to Figure 1 , step S5 further includes detecting whether the output model meets the standard. If not, a light guide bar product model is established based on the output model, and then it returns to step S2.

[0051] First, through closed-loop feedback optimization design and iterative updating of the light guide bar product model, the geometric compensation amount gradually approaches the theoretical optimal value, avoiding the low efficiency problem caused by repeatedly modifying the mold in the traditional trial-and-error method, and improving the design accuracy and reliability. Second, it replaces the traditional way of manually adjusting product parameters, and greatly reduces the time spent on correcting compensation parameters.

[0052] Specifically, referring to Figures 2-7 , step S2 further includes: performing mold flow analysis on the light guide bar product model based on material parameters and process parameters.

[0053] For example, moldflow is used to perform mold flow analysis on the light guide bar product model.

[0054] Combined with material and process parameters for simulation, accurately predict the deformation trend in actual molding, reduce the prediction deviation caused by lack of experience. At the same time, predict and avoid defects caused by process parameter mismatch at the mold flow stage, and reduce the trial mold cost.

[0055] Specifically, performing mold flow analysis on the light guide bar product model based on material parameters and process parameters includes selecting the mold surface temperature and the melt temperature to determine the molding data of the light guide bar product model.

[0056] For example, set the mold surface temperature to 80 °C and the melt temperature to 290 °C.

[0057] Combined with the interaction between the melt temperature and the mold surface temperature, accurately simulate the phase change process of the material from the molten state to the solid state, and greatly reduce the shrinkage deformation prediction error.

[0058] Specifically, performing mold flow analysis on the light guide bar product model based on material parameters and process parameters further includes selecting the injection time, holding pressure time, and holding pressure to determine the melt filling data.

[0059] For example, select a holding pressure of 80 MPa, an injection time of 2.5 s, and a holding pressure time of 6 s.

[0060] First, by optimizing the matching of injection time and holding pressure, the uniformity of the melt flow front velocity is improved to avoid short shot or cavitation defects caused by uneven filling. Second, by coupling the holding time and holding pressure, the melt cooling shrinkage is effectively compensated, and the volume shrinkage rate of the light guide bar is effectively increased compared with the traditional method. Third, through the collaborative analysis of multiple parameters, the injection molding process is comprehensively simulated to optimize the molding quality and avoid the limitations of single parameter analysis.

[0061] Specifically, the material parameters also include the material PVT curve and material thermal performance parameters, which are used for mold flow analysis of the light guide bar product model.

[0062] For example, in this application, the light guide bar selects the Covestro PC HL-3003 material.

[0063] First, based on the PVT curve, the volume change of the material during the melting-cooling phase change is quantified to reduce the shrinkage rate prediction error. Second, by combining the material thermal conductivity and the mold cooling rate, the influence of the local temperature gradient on the microstructure forming is predicted. Third, for different materials, the mold flow analysis parameters are dynamically adjusted to reduce the matching error of the shrinkage compensation amounts of the two materials under the same process and reduce the overcompensation rate.

[0064] For example, referring to Figures 3-5 , according to the deformations in the XYZ three directions generated in the mold flow analysis, the light guide bar product model is compensated and adjusted. Figure 6 This is an example of the predicted deformation amount after mold flow analysis for the light guide bar mentioned in this embodiment. Figure 7 This is an example of compensating and adjusting the light guide bar product model.

[0065] Specifically, step S2 further includes: establishing an optical model of the light guide bar according to the refractive index and surface scattering coefficient.

[0066] For example, the refractive index is selected as 1.586 and the surface scattering coefficient is 0.0015 mm.

[0067] Again for example, ANSY Speos is used to perform optical simulation on the optical model of the light guide bar.

[0068] First, the light path offset of the deformed light guide bar is quantified by the refractive index, and the surface microstructure defects are evaluated by combining the scattering coefficient to reduce the prediction error of the light intensity uniformity. Second, based on the optical parameter mapping, the recognition accuracy of the light effect defect area is improved, the compensation area is reduced, and the waste of resources caused by ineffective compensation is avoided. Third, the influence of deformation on the light effect is quantified through optical parameter modeling, replacing the traditional compensation method that only depends on geometric deformation, and improving the pertinence of light effect repair.

[0069] Specifically, referring to Figure 1 、Figure 8 and Figure 9 In step S3, preprocessing is performed on the optical model of the light guide bar, and the preprocessing includes setting the target optical parameters of the optical model of the light guide bar.

[0070] Define the light efficiency design goal to provide a benchmark for the compensation amount calculation and avoid the compensation direction deviating from the actual requirements.

[0071] Specifically, referring to Figure 8 and Figure 9 step S5 further includes: obtaining the deformed light guiding parameters according to the model deformation data, obtaining the model compensation amount according to the deformed light guiding parameters, and the model compensation amount is:

[0072] = +k·( - );

[0073] wherein, is the deformed light guiding parameter, is the target optical parameter, is the compensation parameter, and k is the material-structure coefficient.

[0074] First, couple the geometric deformation and optical performance through the k value to improve the repair efficiency of light intensity uniformity. Second, for the deformation and non-linear response of light intensity loss in the curved surface area of the light guide bar, improve the compensation accuracy through mathematical model fitting.

[0075] Specifically, referring to Figure 9 , the material-structure coefficient is selected through the light flux loss rate, and the calculation formula of the light flux loss rate is: (initial design light flux - measured light flux) / initial design light flux × 100%, where the initial design light flux is the target light flux, and the measured light flux is obtained by actually measuring the output model.

[0076] First, reduce the production cost and reduce over-compensation according to the measured light flux loss rate. Second, for the performance fluctuations of different batches of the same material, improve the light flux consistency of the light guide bar by controlling the k value. Third, dynamically optimize the compensation coefficient based on the measured light flux to solve the problem that the traditional fixed compensation coefficient cannot adapt to different materials and structures.

[0077] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A deformation compensation design method for an automobile light guide strip, characterized in that: The deformation compensation design method comprises: Step S1, establishing a light guide strip product model; Step S2, performing mold flow analysis on the light guide strip product model to obtain model deformation data; Step S3, establishing a light guide strip optical model based on the model deformation data; Step S4, simulating the optical model of the light guide strip to obtain a light effect defect area; Step S5, obtaining a model compensation amount based on the light effect defect area, and generating an output model based on the model compensation amount; The S5 further includes: obtaining a light guide parameter after deformation according to the model deformation data, and obtaining the model compensation amount according to the light guide parameter after deformation, wherein the model compensation amount is: = +k·( - ); in, is the light guiding parameter after deformation, is the target optical parameter, is a compensation parameter, k is a material-structure coefficient, and the material-structure coefficient is selected by the luminous flux loss rate, the luminous flux loss rate = (initial design luminous flux - measured luminous flux) / initial design luminous flux × 100%, the initial design luminous flux is the target luminous flux of the automotive light guide strip, and the measured luminous flux is obtained by measuring the output model.

2. The deformation compensation design method according to claim 1, characterized in that: The step S5 further includes: detecting whether the output model meets the standard, and if not, rebuilding the light guide strip product model according to the output model, and then returning to step S2.

3. The deformation compensation design method according to claim 1, characterized in that: The step S2 further includes: performing mold flow analysis on the light guide strip product model based on material parameters and process parameters.

4. The deformation compensation design method according to claim 3, characterized in that: The mold flow analysis of the light guide strip product model based on material parameters and process parameters includes selecting mold surface temperature and melt temperature to obtain molding data of the light guide strip product model.

5. The deformation compensation design method according to claim 4, characterized in that: The mold flow analysis of the light guide strip product model based on material parameters and process parameters also includes selecting injection time, holding time and holding pressure to determine melt filling data.

6. The deformation compensation design method according to claim 5, characterized in that: The material parameters include: material PVT curve and material thermal performance parameters, which are used to perform mold flow analysis on the light guide strip product model.

7. The deformation compensation design method according to claim 1, characterized in that: The step S2 also includes: establishing an optical model of the light guide strip according to the refractive index and the surface scattering coefficient.

8. The deformation compensation design method according to claim 1, characterized in that: The step S3 further includes: preprocessing the optical model of the light guide bar, and the preprocessing includes: setting target optical parameters of the optical model of the light guide bar.

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