Deformable SPR riveting die optimization method

Abstract

The invention discloses a deformable SPR (Surface Plasmon Resonance) riveting die optimization method, which relates to the technical field of riveting dies, and comprises the following steps: acquiring appearance and geometrical shape data of a riveting die and a key region related to riveting in real time through 3D (Three-Dimensional) scanning, comparing the appearance and geometrical shape data of the riveting die with a design model, and determining the riveting quality of the riveting die. The finite element analysis is utilized to diagnose whether the deformation mode analysis of the riveting die is used for correcting the riveting die or not; when the riveting die is corrected, the riveting die is calibrated through an automatic adjusting mechanism, the depth of an inner cavity is adjusted, the corrected riveting die is detected again, and it is ensured that correction is effective; comprehensively evaluating the state of the riveting die in combination with the initial precision of the riveting die and the parting surface adjustment value; comprehensively evaluating the number of steps for detecting the corrected riveting die through finite element analysis according to the riveting die state and the inner cavity depth amplitude change value; by optimizing the number of steps for detecting the corrected riveting die through finite element analysis, the detection efficiency of the corrected riveting die can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of riveting dies, and more particularly to a method for optimizing a deformable SPR riveting die. Background Art

[0002] In the existing SPR technology, the rivet die is a key tool, and its accuracy and stability are crucial to the quality of riveting. Traditional rivet dies often have deviations in shape and size due to factors such as material deformation, processing errors, and wear during use, which in turn affects the accuracy and quality of riveting. Especially in the riveting process with high precision requirements, this deviation may cause problems such as inaccurate pressing force, inaccurate positioning, and uneven pressure distribution, thereby affecting the performance and reliability of the final product. In order to solve the above problems, the method currently commonly used is to regularly inspect and correct the rivet die.

[0003] However, after the correction, the rivet needs to be re-tested to ensure that the correction is effective. The traditional procedure of re-inspecting the corrected rivet die is relatively cumbersome and cannot ensure the efficiency of the inspection. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a deformable SPR riveting die optimization method to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: The method for optimizing a deformable SPR riveting die comprises the following steps: S1, acquiring appearance and geometric shape data of the riveting die and the riveted area in real time through 3D scanning, comparing the appearance and geometric shape data of the riveting die with the design model, and using finite element analysis to diagnose the deformation mode of the riveting die to analyze whether the riveting die should be corrected; S2. When the riveting die is corrected, the riveting die is calibrated and the inner cavity depth is adjusted through the automatic adjustment mechanism, and the corrected riveting die is re-tested to ensure that the correction is effective; S3, obtaining the initial fit clearance deviation and temperature deviation of the riveting mold, analyzing the initial accuracy of the riveting mold according to the fit clearance deviation and the temperature deviation, obtaining the parting surface adjustment value of the corrected riveting mold according to the change of the inner cavity depth of the riveting mold, and comprehensively evaluating the riveting mold state in combination with the initial accuracy of the riveting mold and the parting surface adjustment value; S4. Collect the historical values ​​of the change in the inner cavity depth amplitude of the corrected riveting die, and comprehensively evaluate the number of steps for the finite element analysis to detect the corrected riveting die according to the riveting die state and the values ​​of the change in the inner cavity depth amplitude.

[0006] In a preferred embodiment, the appearance and geometric shape of the riveting mold and the riveted area are 3D scanned to obtain the three-dimensional point cloud data of the riveting mold, and the three-dimensional point cloud data of the riveting mold is processed. First, the three-dimensional point cloud data is denoised, then the three-dimensional point cloud data is registered, and then the three-dimensional point cloud data is optimized for point cloud density, and finally the three-dimensional point cloud data is converted into a 3D model. The data of the design model is obtained through the historical model database, and the three-dimensional point cloud data of the processed riveting mold is compared with the design model using 3D comparison software to generate a deviation map. The data in the deviation map includes shape error data and geometric deviation data. According to the geometric shape and material properties of the design model, a finite element analysis model of the riveting mold is established in the 3D software, and the system inputs the data in the deviation map into the finite element analysis model to evaluate the riveting mold.

[0007] Specifically, through 3D scanning and finite element analysis, the deformation mode of the riveting die can be accurately diagnosed, thereby guiding the correction process and reducing the blindness of the correction and the cost of trial and error.

[0008] In a preferred embodiment, the actual clearance between the parts of the riveting die is obtained, the fitting clearance between the parts of the design model is obtained according to the data of the design model obtained from the historical model database, and the actual clearance between the parts of the riveting die is compared with the fitting clearance between the parts of the design model to calculate the initial fitting clearance deviation of the riveting die. The specific calculation formula of the initial fitting clearance deviation of the riveting die is: ΔG = , where ΔG is the initial fit clearance deviation of the riveting die, is the actual gap between the parts of the riveting die, To design the clearance between the components of the model, the actual temperature of the riveting die is obtained through a temperature measuring instrument, the standard temperature of the design model is obtained according to the historical model database, and the temperature deviation of the riveting die is calculated based on the actual temperature and the standard temperature. The specific calculation formula is: ΔT = ; where ΔT is the temperature deviation, is the actual temperature of the riveting die, is the standard temperature of the design model; the initial accuracy of the riveting die is analyzed according to the fit clearance deviation ΔG and the temperature deviation ΔT, and the final initial accuracy of the riveting die is obtained by normalization and weighted calculation, wherein the formula for normalizing the fit clearance deviation ΔG and the temperature deviation ΔT is: ; is the normalized fit clearance deviation, Allowable tolerance for fit clearance; ; is the normalized temperature deviation, is the temperature tolerance; the initial accuracy of the riveting die is calculated by combining the normalized fit clearance deviation and temperature deviation through a weighted formula. The specific formula is: U= + ; Among them, U is the initial accuracy of the riveting die, is the weight coefficient of the normalized fit clearance deviation, is the weight coefficient of the normalized temperature deviation.

[0009] Specifically, by denoising, registering and optimizing the point cloud density of three-dimensional point cloud data, the accuracy and completeness of the data can be improved, providing a reliable basis for subsequent analysis and correction.

[0010] In a preferred embodiment, the actual inner cavity depth of the rivet mold is obtained by a 3D scanning instrument, the standard inner cavity depth of the design model is obtained by a historical model database, and the change of the inner cavity depth of the rivet mold is obtained according to the actual inner cavity depth and the standard inner cavity depth. The specific calculation formula is: ΔD = ; Among them, ΔD is the change in the depth of the riveting mold cavity, is the actual inner cavity depth of the riveting die, is the standard inner cavity depth of the design model; the parting surface adjustment value of the corrected rivet mold is calculated according to the change of the inner cavity depth of the rivet mold. The specific calculation formula is ΔZ=ΔD×θ; where ΔZ is the parting surface adjustment value, ΔD is the change of the inner cavity depth of the rivet mold, The parting surface angle is used to comprehensively evaluate the riveting die state by combining the initial accuracy of the riveting die and the adjustment value of the parting surface. The specific formula is: Q=U× +ΔZ× ; Among them, Q is the riveting die state, is the weight of the initial accuracy of the riveting die, is the weight of the parting surface adjustment value.

[0011] Specifically, a comprehensive evaluation of the riveting die status by combining the initial accuracy of the riveting die and the adjustment value of the parting surface can comprehensively reflect the performance and status of the riveting die to guide the correction process of the riveting die and make it more targeted and effective.

[0012] In a preferred embodiment, the inner cavity depth amplitude variation values ​​of historical revised rivet dies are collected, and the number of steps of finite element analysis to detect the revised rivet die is comprehensively evaluated based on the rivet die state and the inner cavity depth amplitude variation values; based on the data of the historical revised rivet die, the inner cavity depth variation of the historical revised rivet die is averaged as the inner cavity depth amplitude variation value of the historical revised rivet die; and the number of steps of finite element analysis to detect the revised rivet die is evaluated by fuzzy reasoning.

[0013] The technical effects and advantages of the deformable SPR riveting die optimization method of the present invention are as follows: the number of steps for finite element analysis to detect the corrected riveting die is comprehensively evaluated according to the riveting die state and the change value of the inner cavity depth amplitude, which is conducive to optimizing the number of steps for finite element analysis to detect the corrected riveting die and improving the detection efficiency.

[0014] The present invention can accurately diagnose the deformation mode of the riveting die through 3D scanning and finite element analysis, thereby guiding the correction process and reducing the blindness of the correction and the trial and error cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the deformable SPR riveting die optimization method of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In the present invention, SPR is the abbreviation of Self-Piercing Riveting, which is a rivet-free cold connection technology mainly used for the connection of lightweight materials (such as aluminum alloys and composite materials). The riveting die needs to withstand high dynamic loads in the SPR process, and its deformation directly affects the riveting quality and die life.

[0018] Example The present invention discloses a deformable SPR riveting die optimization method, referring to Figure 1 , including the following steps: S1. Obtain the appearance and geometric shape data of the riveting die and the riveted area in real time through 3D scanning, compare the appearance and geometric shape data of the riveting die with the design model, and use finite element analysis to diagnose the deformation mode of the riveting die to analyze whether the riveting die should be corrected; S2. When the riveting die is corrected, the riveting die is calibrated and the inner cavity depth is adjusted through the automatic adjustment mechanism, and the corrected riveting die is re-tested to ensure that the correction is effective; S3, obtaining the initial fit clearance deviation and temperature deviation of the riveting mold, analyzing the initial accuracy of the riveting mold according to the fit clearance deviation and the temperature deviation, obtaining the parting surface adjustment value of the corrected riveting mold according to the change of the inner cavity depth of the riveting mold, and comprehensively evaluating the riveting mold state in combination with the initial accuracy of the riveting mold and the parting surface adjustment value; S4. Collect the historical values ​​of the change in the inner cavity depth amplitude of the corrected riveting die, and comprehensively evaluate the number of steps for the finite element analysis to detect the corrected riveting die according to the riveting die state and the values ​​of the change in the inner cavity depth amplitude.

[0019] In this implementation, S1 includes the following process: The appearance and geometric shape of the rivet mold and the riveted area are 3D scanned by a 3D scanning instrument to obtain the 3D point cloud data of the rivet mold, and the 3D point cloud data of the rivet mold is processed. First, the 3D point cloud data is denoised, then the 3D point cloud data is registered, and then the 3D point cloud data is optimized. Point cloud density processing is finally converted into a 3D model.

[0020] The data of the design model is obtained through the historical model database, and the 3D point cloud data of the processed rivet die is compared with the design model using 3D comparison software to generate a deviation map. The data in the deviation map includes shape error data and geometric deviation data.

[0021] It needs to be explained that a 3D scanning instrument is a device specifically used to obtain data on the appearance and geometric shape of an object. The historical model database is a database that stores and manages past design models, manufacturing processes and actual measurement results. The design model data in the historical model database is established by design professionals in related fields based on historical data, which will not be elaborated here.

[0022] According to the geometric shape and material properties of the design model, a finite element analysis model of the rivet die is established in the 3D software. The system inputs the data in the deviation diagram into the finite element analysis model to evaluate the rivet die. The specific steps of the finite element analysis model to evaluate the rivet die are: Step 1: Perform stress, heat, and deformation analysis on the rivet die to verify whether the riveting effect of the rivet die meets expectations; Step 2: Perform a comprehensive structural analysis on the rivet die to evaluate the overall performance of the rivet die; Step 3: Perform a thermal-mechanical coupling analysis on the rivet die to consider the impact of temperature changes on the strength and deformation of the die; Step 4: Simulate the long-term behaviors of the rivet die such as fatigue life, wear, and crack propagation to evaluate the service life; Step 5: Perform parameter sensitivity analysis on the rivet die to find out the key factors that may affect the performance; Step 6: Based on the analysis results of the steps, evaluate whether the deformation mode of the rivet die can be used normally in the current design. When the deformation mode of the rivet die is lower than the predetermined threshold, the finite element analysis diagnosis results in the need to correct the rivet die.

[0023] It should be noted that establishing a finite element analysis model of a riveting die in 3D software is a conventional prior art, and will not be described in detail again. For example, the specific steps of establishing a finite element analysis model may be as follows: Model basic construction: Geometric model import: Convert the rivet mold point cloud data generated by 3D scanning into a solid model (such as STL format) and import it into the finite element analysis software.

[0024] Material property definition: According to the actual material of the riveting die (such as tool steel, cemented carbide, etc.), input basic parameters such as elastic modulus, Poisson's ratio, density, thermal expansion coefficient, etc.

[0025] Meshing: Dense grids are used in key areas (such as the inner cavity of the riveting mold and the parting surface) to ensure the accuracy of stress and deformation analysis; A coarser grid is used in non-critical areas to reduce the amount of calculation.

[0026] Boundary condition settings: Fix the mounting surface of the riveting die (constrain the displacement and rotational freedom); Apply dynamic loads (pressure, impact force) during the riveting process.

[0027] Thermal-mechanical coupling modeling: Heat source definition: Based on the riveting process parameters (such as friction coefficient and riveting speed), calculate the frictional heat generated on the contact surface of the riveting die.

[0028] Temperature field analysis: simulate the temperature distribution of the riveting die during the riveting process and its changes over time.

[0029] Thermal stress calculation: Import the temperature field results into the structural analysis module to calculate the additional stress caused by thermal expansion.

[0030] In this implementation, S2 includes the following process: When the riveting die is corrected, the automatic adjustment mechanism is used to calibrate the riveting die and adjust the inner cavity depth. The corrected riveting die is re-tested to ensure that the correction is effective. During the manufacturing process, the rivet die may deviate or be distorted due to material deformation, processing error, wear, etc., especially in the riveting process that requires high precision. The accuracy of the shape and size of the rivet die directly affects the quality and precision of the riveting. In order to ensure that the correct pressing force, precise positioning and uniform pressure distribution can be obtained during the riveting process, finite element analysis is used to diagnose the deformation mode of the rivet die to analyze whether the rivet die should be corrected. The purpose of riveting die correction is to restore it to the shape and size required by the design to ensure its accuracy in subsequent production.

[0031] Specifically, the riveting mold evaluation method and judgment criteria are as follows: Stress Analysis: Purpose: To identify stress concentration areas in the riveting die and prevent material failure.

[0032] Result verification: If the maximum stress is lower than the safety threshold of the material yield strength (for example, 80%), it is in line with expectations; if it exceeds the threshold, correction is required.

[0033] Deformation analysis: Purpose: To detect geometric deviations in critical areas of the riveting die (e.g. cavity depth, parting surface offset).

[0034] Result verification: If the deformation is within the design tolerance range, it is in line with expectations; if it exceeds the tolerance, correction is required.

[0035] Thermal Analysis: Purpose: To evaluate the effect of temperature on the properties of riveting dies (e.g. thermal softening, thermal fatigue).

[0036] Result verification: If the maximum temperature is lower than the thermal stability limit of the material and the temperature gradient is reasonable, it is in line with expectations; otherwise, the cooling design needs to be optimized.

[0037] Correction trigger condition: When any of the stress, deformation or temperature analysis exceeds the allowable range, it is determined that the riveting die needs to be corrected.

[0038] Example: The stress concentration area is close to the material yield limit → the structure needs to be optimized (such as adding fillets); The inner cavity depth is out of tolerance → adjust the inner cavity size; Temperature is too high → add cooling channels or reduce riveting speed.

[0039] When the rivet die needs to be corrected, the automatic adjustment mechanism uses automated equipment and control systems to accurately adjust the rivet die. Specifically, the actuator is used to correct the rivet die according to the data in the deviation diagram to adjust the size, shape and inner cavity depth of the rivet die. It should be explained that the actuator is a device that can automatically perform physical actions based on input signals or control system instructions.

[0040] The corrected riveting die needs to be tested again to ensure that the adjustments made are effective and that the riveting die can operate normally in actual work and meet the riveting accuracy and mechanical requirements.

[0041] In this implementation, S3 includes the following process: Obtain the initial fit clearance deviation and temperature deviation of the riveting mold, analyze the initial accuracy of the riveting mold based on the fit clearance deviation and temperature deviation, obtain the parting surface adjustment value of the corrected riveting mold based on the change in the inner cavity depth of the riveting mold, and comprehensively evaluate the riveting mold status based on the initial accuracy of the riveting mold and the parting surface adjustment value; The actual gap between the parts of the rivet die is obtained by a high-precision laser rangefinder. The matching gap between the parts of the design model is obtained according to the historical model database. The actual gap between the parts of the rivet die is compared with the matching gap between the parts of the design model to calculate the initial matching gap deviation of the rivet die. The specific calculation formula for the initial matching gap deviation of the rivet die is: ΔG = , where ΔG is the initial fit clearance deviation of the riveting die, is the actual gap between the parts of the riveting die, is the clearance between the design model components; for example, when the actual clearance between the rivet die parts is 0.045 mm and the clearance between the design model components is 0.05 mm, ΔG = = =0.005mm, that is, the initial fitting clearance deviation of the riveting die is 0.005mm.

[0042] The actual temperature of the riveting die is obtained by the temperature measuring instrument, the standard temperature of the design model is obtained according to the historical model database, and the temperature deviation of the riveting die is calculated according to the actual temperature and the standard temperature. The specific calculation formula is: ΔT = ; where ΔT is the temperature deviation, is the actual temperature of the riveting die, is the standard temperature of the design model; Assume that the standard temperature of the design model =25℃, the actual temperature of the riveting die =30℃, then ΔT= =5℃, the temperature deviation of the riveting die is 5℃; the initial accuracy of the riveting die is analyzed according to the matching clearance deviation ΔG and the temperature deviation ΔT, and the final initial accuracy of the riveting die is obtained by normalization and weighted calculation. Among them, the formula for normalizing the matching clearance deviation ΔG and the temperature deviation ΔT is: ; is the normalized fit clearance deviation, Allowable tolerance for fit clearance; ; is the normalized temperature deviation, is the temperature tolerance; the initial accuracy of the riveting die is calculated by combining the normalized fit clearance deviation and temperature deviation through a weighted formula. The specific formula is: U= + ; Among them, U is the initial accuracy of the riveting die, is the weight coefficient of the normalized fit clearance deviation, is the weight coefficient of the normalized temperature deviation; assuming that the clearance deviation ΔG = 0.005 mm, the temperature deviation ΔT = 5°C, and the clearance tolerance = 0.01mm, temperature tolerance = 2°C, weight coefficient of normalized fit clearance deviation =0.6, weight coefficient of normalized temperature deviation =0.4; = =0.5; =2.5; U= + =0.6×0.5+0.4×2.5=1.3, then, the initial accuracy of the riveting die is 1.3; a smaller value of the initial accuracy of the riveting die means that the accuracy of the riveting die is higher, and a larger value of the initial accuracy of the riveting die means that the error is larger and the accuracy of the riveting die is lower.

[0043] The actual inner cavity depth of the rivet mold is obtained through a 3D scanning instrument, and the standard inner cavity depth of the design model is obtained through the historical model database. The change of the inner cavity depth of the rivet mold is obtained according to the actual inner cavity depth and the standard inner cavity depth. The specific calculation formula is: ΔD = ; Among them, ΔD is the change in the depth of the riveting mold cavity, is the actual inner cavity depth of the riveting die, is the standard inner cavity depth of the design model; the parting surface adjustment value of the corrected rivet mold is calculated according to the change of the inner cavity depth of the rivet mold. The specific calculation formula is ΔZ=ΔD×θ; where ΔZ is the parting surface adjustment value, ΔD is the change of the inner cavity depth of the rivet mold, is the parting surface angle.

[0044] The weighted formula is used to comprehensively evaluate the riveting die status by combining the initial accuracy of the riveting die and the adjustment value of the parting surface. The specific formula is: Q=U× +ΔZ× ; Among them, Q is the riveting die state, is the weight of the initial accuracy of the riveting die, is the weight of the parting surface adjustment value; assuming that ΔD=0.5mm, θ=2°, the actual cavity depth is 10.05mm, and the standard cavity depth is 10mm. =0.7, =0.3, then ΔD= =10.05mm−10mm=0.05mm, ΔZ=ΔD×θ=0.05mm×2°=0.1mm, Q=U× +ΔZ× =0.7×1.3+0.3×0.1=0.91+0.03=0.94; the smaller the value of the riveting die state, the more ideal the riveting die state is, and the larger the value of the riveting die state, the worse the riveting die state is.

[0045] In this implementation, S4 includes the following process: The inner cavity depth amplitude variation values ​​of the historically corrected riveting dies are collected, and the number of steps for finite element analysis to detect the corrected riveting dies is comprehensively evaluated based on the riveting die state and the inner cavity depth amplitude variation values.

[0046] According to the data of historical revised riveting dies, the changes of the inner cavity depth of the historical revised riveting dies are averaged and processed as the amplitude change value of the inner cavity depth of the historical revised riveting dies.

[0047] The specific working process for evaluating the number of steps that the finite element analysis can perform on the modified riveting die is as follows: Step 1: Define the riveting die state and the change value of the inner cavity depth amplitude as input variables, and divide them into different fuzzy sets respectively.

[0048] For example, "Low", "Medium", "High" for the riveting die status, "Small", "Medium", "Large" for the inner cavity depth amplitude change value; Step 2, define the number of steps of finite element analysis to detect the modified rivet die as the output variable, and divide it into fuzzy sets, for example, "Few", "Many" for the number of steps of finite element analysis to detect the modified rivet die.

[0049] Step 3: Develop a set of fuzzy rules to describe the impact of different input variables on output variables. The definition of rules can be based on professional knowledge or obtained through data analysis and experiments. For example: The riveting die state is marked as X, the change value of the inner cavity depth amplitude is marked as V, and the number of steps of finite element analysis on the corrected riveting die is marked as J, then it can be defined Rule 1: IF (X is High) AND (V is Large) THEN (J is Many) Rule 2: IF (X is Low) AND (V is Small) THEN (J is Few) ... Step 4, performing fuzzy reasoning according to fuzzy rules to determine a division scheme for the number of steps of testing the corrected riveting die by finite element analysis.

[0050] It should be noted that the division of fuzzy sets can be adjusted according to actual conditions. For example, although the present embodiment takes three fuzzy sets as examples, in fact, the riveting die state, the change value of the inner cavity depth amplitude, and the number of steps for finite element analysis to detect the corrected riveting die can be divided into more than three sets to facilitate a better division of the number of steps for finite element analysis to detect the corrected riveting die.

[0051] Furthermore, for the judgment of the riveting mold state and the amplitude change value of the inner cavity depth, the threshold value can be set according to the actual situation. For example, when the riveting mold state does not exceed 1.5, it is marked as "Low", and when the amplitude change value of the inner cavity depth is not higher than 0.2, it is marked as "Small", and so on. I will not go into details here.

[0052] Among them, when the output variable is "Few", the number of steps for the finite element analysis to detect the corrected rivet die is a large number, and when the output variable is "Many", the number of steps for the finite element analysis to detect the corrected rivet die is a small number.

[0053] In summary, comprehensively evaluating the number of steps for finite element analysis to detect the corrected rivet die according to the rivet die state and the change value of the inner cavity depth amplitude is conducive to optimizing the number of steps for finite element analysis to detect the corrected rivet die and improving the detection efficiency.

[0054] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0055] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0056] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application of the technical solution and the invention constraints. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0057] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0058] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0059] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A deformable SPR riveting die optimization method, characterized in that; The steps include: S1. Obtain the appearance and geometric shape data of the riveting die and the riveted area in real time through 3D scanning, compare the appearance and geometric shape data of the riveting die with the design model, and use finite element analysis to diagnose the deformation mode of the riveting die to analyze whether the riveting die should be corrected; S2. When the riveting die is corrected, the riveting die is calibrated and the inner cavity depth is adjusted through the automatic adjustment mechanism, and the corrected riveting die is re-tested to ensure that the correction is effective; S3, obtaining the initial fit clearance deviation and temperature deviation of the riveting mold, analyzing the initial accuracy of the riveting mold according to the fit clearance deviation and the temperature deviation, obtaining the parting surface adjustment value of the corrected riveting mold according to the change of the inner cavity depth of the riveting mold, and comprehensively evaluating the riveting mold state in combination with the initial accuracy of the riveting mold and the parting surface adjustment value; S4. Collect the historical values ​​of the change in the inner cavity depth amplitude of the corrected riveting die, and comprehensively evaluate the number of steps for the finite element analysis to detect the corrected riveting die according to the riveting die state and the values ​​of the change in the inner cavity depth amplitude.

2. The deformable SPR riveting die optimization method according to claim 1, characterized in that: By performing 3D scanning on the appearance and geometric shape of the riveting die and the riveted area, the 3D point cloud data of the riveting die is obtained, and the 3D point cloud data of the riveting die is processed. First, the 3D point cloud data is denoised, then the 3D point cloud data is registered, and then the 3D point cloud data is optimized. Finally, the 3D point cloud data is converted into a 3D model; The data of the design model is obtained through the historical model database, and the 3D point cloud data of the processed riveting die is compared with the design model using 3D comparison software to generate a deviation map. The data in the deviation map includes shape error data and geometric deviation data; According to the geometric shape and material properties of the design model, a finite element analysis model of the rivet die is established in the 3D software. The system inputs the data in the deviation diagram into the finite element analysis model to evaluate the rivet die.

3. The deformable SPR riveting die optimization method according to claim 2, characterized in that: By obtaining the actual gap between the parts of the riveting die, the matching gap between the parts of the design model is obtained according to the historical model database, and the actual gap between the parts of the riveting die is compared with the matching gap between the parts of the design model to calculate the initial matching gap deviation of the riveting die. The specific calculation formula for the initial matching gap deviation of the riveting die is: ΔG = , where ΔG is the initial fit clearance deviation of the riveting die, is the actual gap between the parts of the riveting die, To design the clearance between the components of the model, the actual temperature of the riveting die is obtained through a temperature measuring instrument, the standard temperature of the design model is obtained according to the historical model database, and the temperature deviation of the riveting die is calculated based on the actual temperature and the standard temperature. The specific calculation formula is: ΔT = ; where ΔT is the temperature deviation, is the actual temperature of the riveting die, is the standard temperature of the design model; The initial accuracy of the riveting die is analyzed according to the fit clearance deviation ΔG and the temperature deviation ΔT, and the final initial accuracy of the riveting die is obtained by normalization and weighted calculation. The formula for normalizing the fit clearance deviation ΔG and the temperature deviation ΔT is: ; is the normalized fit clearance deviation, Allowable tolerance for fit clearance; ; is the normalized temperature deviation, is the temperature tolerance; the initial accuracy of the riveting die is calculated by combining the normalized fit clearance deviation and temperature deviation through a weighted formula. The specific formula is: U= + ; Among them, U is the initial accuracy of the riveting die, is the weight coefficient of the normalized fit clearance deviation, is the weight coefficient of the normalized temperature deviation.

4. The deformable SPR riveting die optimization method according to claim 3, characterized in that: The actual inner cavity depth of the rivet mold is obtained through a 3D scanning instrument, and the standard inner cavity depth of the design model is obtained through the historical model database. The change of the inner cavity depth of the rivet mold is obtained according to the actual inner cavity depth and the standard inner cavity depth. The specific calculation formula is: ΔD = ; Among them, ΔD is the change in the depth of the riveting mold cavity, is the actual inner cavity depth of the riveting die, is the standard inner cavity depth of the design model; the parting surface adjustment value of the corrected rivet mold is calculated according to the change of the inner cavity depth of the rivet mold. The specific calculation formula is ΔZ=ΔD×θ; where ΔZ is the parting surface adjustment value, ΔD is the change of the inner cavity depth of the rivet mold, is the parting surface angle; The weighted formula is used to comprehensively evaluate the riveting die status by combining the initial accuracy of the riveting die and the adjustment value of the parting surface. The specific formula is: Q=U× +ΔZ× ; Among them, Q is the riveting die state, is the weight of the initial accuracy of the riveting die, is the weight of the parting surface adjustment value.

5. The deformable SPR riveting die optimization method according to claim 4, characterized in that: Collect the inner cavity depth amplitude change values ​​of the historical revised riveting mold, and comprehensively evaluate the number of steps of the finite element analysis to detect the revised riveting mold according to the riveting mold state and the inner cavity depth amplitude change value; according to the data of the historical revised riveting mold, average the inner cavity depth changes of the historical revised riveting mold as the inner cavity depth amplitude change value of the historical revised riveting mold; The number of steps of finite element analysis for testing the modified riveting die was evaluated by fuzzy reasoning.

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