Structural design modeling method for inclined crown spring large-current connector

Abstract

The invention discloses an oblique crown spring large-current connector structure design modeling method which comprises the following steps: S1, selecting oblique crown spring structure parameters as design variables, and designing an orthogonal experiment table; s2, drawing an inclined crown spring and matched pin jack model by using three-dimensional modeling software; and S3, carrying out geometric subdivision on the model based on an APDL language, confirming material attributes and defining unit types. S4, performing grid division on the geometry to form a finite element model; and S5, automatically defining a contact pair based on an APDL language, applying a load, defining a solver and solving. S6, designing an optimization target, writing a post-processing program, and performing extraction and calculation; s7, establishing a regression prediction model of the optimization target; s8, designing a simulation experiment to verify the accuracy of the regression prediction model; and S9, establishing a multi-objective optimization function, and obtaining an optimal combination of design variables in combination with an optimization algorithm. By means of the method, the oblique crown spring can be conveniently corrected through the parameterized language, and the simulation effect and the calculation efficiency can be effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of electrical connector technology, specifically a structural design and modeling method for a high-current connector with a slanted crown spring. Background Technology

[0002] Electrical connectors are used in industries such as new energy vehicles, aviation, and aerospace. Among them, high-current connectors are widely used in fields requiring efficient power transmission due to their high current carrying capacity, reliability, and durability. Among various contact structures, crown springs are widely used in high-current connectors because of their excellent elastic contact characteristics and stable conductivity.

[0003] As electronic devices evolve towards higher power density and miniaturization, the demand for high-current connectors in confined spaces is increasing. While traditional crown spring structures can meet some high-current transmission requirements, in extremely compact design environments, such as servers, the limited length within the connector socket still presents problems such as the inability to assemble crown springs that meet structural requirements, or forced assembly resulting in spring locking, affecting contact reliability.

[0004] However, due to the wide range of applications and complex working environments of high-current connectors, the performance and lifespan of terminals in actual applications often differ from the test values ​​or numerical model results in the laboratory. Furthermore, directly fabricating physical components for experimental testing is costly. Therefore, to ensure better reliability of high-current connectors, it is necessary to conduct a series of predictions and optimization analyses on performance aspects such as insertion and extraction force, equivalent stress strain, contact normal force, contact area, and temperature rise during the terminal design stage, based on the actual working environment.

[0005] The introduction of finite element analysis (FEA) technology has reduced experimental costs to some extent, but the accuracy of finite element simulation is highly dependent on preprocessing steps such as mesh generation and boundary condition setting. If errors occur in the preprocessing, the simulation data may not accurately reflect the real physical phenomena, affecting the reliability of the optimization design.

[0006] In response to this phenomenon, previous research by experts and scholars in various fields has largely focused on parametric modeling. For example, patent CN114781218A discloses a parametric modeling method for infill core materials based on the APDL language. Using parametric CAE modeling can reduce errors caused by finite element preprocessing and shorten preprocessing time to some extent. However, existing parametric modeling methods still have the following limitations: they are only applicable to geometric features that are simple in structure, easy to model, and easy to describe mathematically. For structures with complex curved surfaces that are difficult to describe precisely using mathematical equations, finite element parametric languages ​​cannot model their structures or curves; only 3D modeling software such as UG can be used to change their parameters to obtain a series of models with the same topological structure. Therefore, a more efficient parametric modeling method and optimization method for structures with complex curved surfaces is needed to improve the design accuracy and development efficiency of crown springs for high-current connectors. Summary of the Invention

[0007] The purpose of this invention is to provide a structural design and modeling method for a high-current connector with a slanted crown spring, in order to solve the following technical problems mentioned in the background art: The oblique crown spring has a combined structure that is difficult to model using parametric languages, resulting in poor simulation effects and low computational efficiency.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A structural design and modeling method for a high-current connector with a slanted crown spring includes the following steps: S1. Select the structural parameters of the oblique crown spring as design variables and design an orthogonal experimental table.

[0009] S2, use 3D modeling software to draw the oblique crown spring and the matching pin and socket model.

[0010] S3 uses the APDL language to perform geometric meshing of the model, confirm material properties, and define element types.

[0011] S4, mesh the geometry to form a finite element model.

[0012] S5 automatically defines contact pairs, applies loads, defines solvers, and solves based on the APDL language.

[0013] S6, Design the optimization objective, write the post-processing program and extract the calculations.

[0014] S7, Establish a regression prediction model for the optimization objective.

[0015] S8. Design simulation experiments to verify the accuracy of the regression prediction model.

[0016] S9. Establish a multi-objective optimization function and combine it with the optimization algorithm to obtain the optimal combination of design variables.

[0017] Furthermore, the length of the vertical contact portion in the middle of the oblique crown spring is selected. l As design variable one, the angle θ between the center of the middle contact part and the center of the spring wire root is selected as design variable two; design variable one and design variable two are each selected with 5 values ​​and formed into an orthogonal experimental table.

[0018] Furthermore, the spring wire of the oblique crown spring is divided into a first part and a second part, wherein the first part is the middle vertical contact part, and the two sides are the second parts; the ring of the oblique crown spring is divided into several third parts and fourth parts, wherein the third part is connected to the spring wire and is provided with a chamfer; the first part, the second part, the third part and the fourth part are each divided into a hexahedral mapping common node mesh; the part of the pin socket that contacts the oblique crown spring is cut and divided into a hexahedral mapping mesh.

[0019] Furthermore, when meshing the first part, the number of mesh layers in the thickness direction is specified using the LESIZE command.

[0020] Furthermore, when meshing the third part, the LESIZE command is used to increase the number of meshes in the chamfered area.

[0021] Furthermore, the optimization targets include the contact area between the pin and the pin surface after insertion, the contact area between the pin and the inner surface of the oblique crown spring after insertion, the contact area between the inner surface of the socket and the outer surface of the oblique crown spring, the stable insertion force, and the pull-out force values.

[0022] Furthermore, the parameter combinations used in the simulation experiment should be parameter combinations within the parameter range other than those used in orthogonal experiments.

[0023] Furthermore, in step S8, the simulation results of the optimized target obtained from the simulation experiment are compared with the calculation results after substituting them into the regression equation, and the relative error is calculated. Judgment based on relative error results: The relative error is less than 10%, indicating that the final optimization result is reliable. If the relative error is ≥10%, the prediction model needs to be adjusted.

[0024] Furthermore, in step S9, the optimal parameter combination solution is obtained based on the genetic optimization algorithm.

[0025] Furthermore, in step S9, the optimal combination of design variables is obtained, the optimal parameter combination solution is verified by simulation, and the simulation results are compared and verified with the complete experimental combination.

[0026] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves systematic analysis and screening of key parameters by designing an orthogonal experimental table through the selection of structural parameters of the oblique crown spring, thus solving the problem of low simulation accuracy caused by blind parameter selection.

[0027] This invention achieves high-precision construction of finite element models by using APDL language to perform geometric subdivision of the model, define material properties and element types, and divide the geometry into hexahedral mapping common node meshes. This solves the problem of simulation data distortion caused by unreasonable mesh division.

[0028] This invention achieves multi-objective optimization of the oblique crown spring structure by designing optimization objectives and establishing a regression prediction model, combined with a genetic optimization algorithm to solve the optimal parameter combination, thus solving the problem that traditional design methods cannot simultaneously consider electrical and mechanical performance. Attached Figure Description

[0029] Figure 1 One of the structural schematic diagrams of the oblique crown spring of the present invention; Figure 2 This is the second schematic diagram of the oblique crown spring of this invention; Figure 3 This is one of the schematic diagrams of the spring wire structure of the present invention; Figure 4 This is a second schematic diagram of the spring wire structure of the present invention; Figure 5 This is a schematic diagram of the annular structure of the present invention; Figure 6 This is a schematic diagram of the structure of the third part of the present invention; Figure 7 This is a schematic diagram of the fourth part of the present invention; Figure 8 This is the third schematic diagram of the oblique crown spring of the present invention; Figure 9 This is a schematic diagram of the mesh division in the second part of the present invention; Figure 10 This is a schematic diagram of the mesh division of the first part of the present invention; Figure 11 This is a schematic diagram of the mesh division in the fourth part of the present invention; Figure 12 This is a schematic diagram of the mesh division in the third part of the present invention; Figure 13 This is a schematic diagram of the mesh division of the pin and socket model of the present invention; Figure 14 This is a schematic diagram of the overall process of the present invention; Figure 15 This is a schematic diagram of the optimized process of the present invention.

[0030] The markings in the diagram are: 1-ring, 2-spring wire, 3-first part, 4-second part, 5-third part, 6-fourth part. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example: This embodiment is used to design a high-current connector with a slanted crown spring. To facilitate understanding of the structural design modeling method, this embodiment also discloses the structure of a high-current connector with a slanted crown spring. It should be noted that this structural design modeling method is not only applicable to this one type of high-current connector with a slanted crown spring, but also applicable to the design of other types of high-current connectors with slanted crown springs. Specifically, such as... Figure 1 As shown, the oblique crown spring high-current connector includes a first ring body, a second ring body, and several spring wires 2; wherein, the centers of the first ring body and the second ring body are located on the same axis, the radii of the first ring body and the second ring body are different, and the first ring body and the second ring body are provided with notches at the same angular position; the first ring body has a continuous material structure similar to that of a traditional crown spring; as shown Figure 2 As shown, several spring wires 2 are arranged between the first ring and the second ring. There is a vertical connection between the spring wires 2 and the first ring. The vertical connection is chamfered with the first ring to disperse stress and avoid excessive local stress.

[0033] like Figure 3 As shown, the spring wire 2 is formed by four spatial curved surfaces to form an S-shaped spatial geometry. Each spatial curved surface consists of two spatial curves and four straight lines. The four straight lines are located at both ends of the spring wire 2. One straight line is used to connect the spatial curve and the vertical connection part, and the other straight line is used to connect the spatial curve and the contact part in the middle.

[0034] It should be noted that regardless of the change in the length of the central rectangular contact area, the following should always be maintained: both ends of the single spring wire 2 spatial curve should always remain tangent to the straight lines at both ends simultaneously. This invention addresses the problem of insufficient axial length in confined spaces, which prevents the assembly of crown springs. A novel oblique crown spring is designed, which, compared to traditional crown springs, offers smoother insertion and removal, a larger contact area, and superior electrical performance and current-carrying capacity.

[0035] A structural design and modeling method for a high-current connector with a slanted crown spring, such as... Figure 14 As shown, it includes the following steps: S1, Select the length of the vertical contact portion in the middle of the oblique crown spring. l ,like Figure 4 As shown, this is design variable one; select the angle θ between the center of the contact part and the center of the second root of the spring wire, as follows. Figure 8 As shown, this is design variable two; design variable one and design variable two are used as optimization variables. Among them, l The value ranges from 0.02mm to 1mm, and the value range of θ is from 2.5° to 22.5°. The contact length... l The contact area is directly affected, and the angle θ affects the degree of elastic deformation of the spring. Therefore, these two are selected as design variables.

[0036] Five levels were selected for each of the two variables, and a five-level, two-factor, completely orthogonal experimental design was created, as shown in Table 1, resulting in a total of 25 parameter combinations. For example, the parameters in the first group were... l =0.02mm, θ=2.5°, the 25th set of parameters is l =1mm, θ=22.5°.

[0037] Table 1 S2. Using 3D modeling software such as UG or SolidWorks, generate the oblique crown spring model based on the orthogonal experimental table parameters. Divide the spring wire 2 into a central vertical contact section and two side sections, namely the first section 3 and the second section 4, as shown below. Figure 3 As shown, the ring 1 is divided into a chamfered region connected to the spring wire 2 and a fan-shaped connection structure, as follows. Figure 5 As shown, that is, Part 5 of the third section and Part 6 of the fourth section, as Figure 6 and Figure 7 As shown. For example, when l When the diameter is 0.5mm and θ is 12.5°, an S-shaped spring wire 2 is generated using the "sweep" function of UG. The spline curve is selected as the guide line, and the depth and skewness of the spline curve are both 50 to ensure the tangency constraint between the curve and the straight line.

[0038] The pin and socket model is designed to fit the dimensions of the oblique crown spring, and the contact area is divided into an extruded body with a hexahedral mapping mesh. During assembly, ensure that the pin axis coincides with the central axis of the oblique crown spring, and leave an initial gap of 0.1mm between the inner wall of the socket and the outer surface of the oblique crown spring.

[0039] S3, based on the APDL language, performs geometric subdivision of assemblies: The first part 3 of the spring wire 2 is divided into rectangular blocks, and the second part 4 is divided into S-shaped curved surfaces.

[0040] The third part 5 of the ring 1 is divided into an octahedron, and the fourth part 6 is divided into sector blocks.

[0041] The contact portion of the pin and socket is divided into a hexahedral extruded body to ensure that a mapping method can be used when meshing.

[0042] The spring material is C70318, with an elastic modulus of 110 GPa, Poisson's ratio of 0.3, and a yield strength of 345 MPa. The pin and socket material is copper, with an elastic modulus of 120 GPa and a Poisson's ratio of 0.33. The main contact parts, such as spring wire 2 and the pin, use SOLID185 elements. Non-contact parts, such as the front end of the socket, use SOLID285 elements. Material properties are assigned using the MP command, and the element type is defined using the ET command.

[0043] S4, for the first part 3 of spring wire 2, i.e., the contact part, use the LESIZE command to specify 5 mesh layers in the thickness direction to ensure different... l The mesh density is consistent across values. For example, when... l When the thickness is 0.3mm, the mesh size in the thickness direction is 0.06mm.

[0044] For Part 3, section 5, the chamfered region, the LESIZE command was used to increase the number of mesh nodes at a single chamfer from 4 to 10. This increased the overall mesh node count by approximately 3%, but simulation results showed that the maximum stress error decreased from 15% to less than 5%. The resulting mesh is shown below. Figures 9 to 12 As shown.

[0045] S5, Contact Pair Settings: Use the ASEL command to select the contact surface between spring wire 2 and the pin as the target surface, and use the NSLA command to select the nodes on the surface to define the contact pair.

[0046] Use the RMODIF command to set the contact stiffness to 100 N / mm and the penetration factor to 0.1, and use the KEYOPT command to set the contact type to "surface-to-surface contact".

[0047] Apply loads, define solvers, and solve: All degrees of freedom at one end of the fixed socket are fixed, and an axial displacement load of 2 mm is applied to one end of the pin. Use the ANTYPE command to set up the transient dynamics solution, the / SOLU command to enter the solution module, and the SOLVE command to start the calculation. Set the solution time step to 0.01s.

[0048] S6, Optimization objective definition, the optimization objectives include: The contact area between the pin and the oblique crown spring represents the contact area of ​​the inner surface; The contact area between the socket and the inclined crown spring represents the contact area of ​​the outer surface; Stable insertion force, representing the extraction force at an extraction time of 1.8 seconds; The pull-out force value represents the pull-out force at a pull-out time of 0.2s.

[0049] Stable insertion force is used to measure the overall level of insertion force. Optimizing both insertion and extraction forces keeps the positive pressure at a moderate level. Optimizing these two indicators helps improve the stability of the insertion phase. Contact area is used to measure the contact resistance and contact performance of high-current connectors. It helps to reduce Joule heating generated at the contact points when energized, improves current concentration, and thus optimizes its electrothermal performance.

[0050] Write a post-processing program and extract the calculations: Enter the post-processing module via the / POST command in APDL, and use the PLNSOL command to view the contact area contour plots and stress contour plots at different times, extracting the optimization target values ​​under various parameter combinations. For example, when l When the diameter is 0.6 mm and the angle is 7.5°, the contact area of ​​the inner surface is 1.28 mm² and the contact area of ​​the outer surface is 1.45 mm².

[0051] S7, Establishing the regression prediction model: 25 sets of simulations were conducted according to the orthogonal experimental table shown in Table 1. The optimization objectives selected in S6 were post-processed, extracted, and sorted. For small sample data with independent variables less than or equal to 2, multiple linear regression is applicable. Linear regression is used for variables including variable yi, variable 2, and their higher-order variables. For data that have completed polynomial fitting, stepwise regression is usually used to remove insignificant variables to improve accuracy. This embodiment uses MATLAB software to perform multiple linear regression analysis between each optimization objective and design variable. First, the multiple linear method is used to obtain a multiple polynomial fitting expression in the form shown in the formula (the formula shows a quadratic polynomial fitting, and the specific degree used depends on the characteristics of the data). Then, the stepwise regression method is used to remove insignificant variables (i.e., p > 0.05), thereby obtaining the functional relationship between the optimization objective and the design variable and completing the establishment of the regression prediction model.

[0052] Where f is the dependent variable; For the intercept term; These are the regression coefficients; As the independent variable; This is the random error term.

[0053] The fitting results for each optimization objective are shown in Table 2: The correlation coefficients are all greater than 0.8, which meets the statistical requirements. However, overfitting may occur with small sample data. To verify that this situation has not occurred, simulation verification using non-sample data is required.

[0054] S8, Perform model validation: Design multiple sets of simulation experiments, excluding orthogonal experimental parameter combinations, and use the results to verify the accuracy of the regression prediction model in S6; the parameter combinations and simulation verification results are shown in Table 3: Table 3 The fact that the combined error of random value interpolation simulation remains within 10% proves that the prediction accuracy is high.

[0055] S9. Establish a multi-objective optimization function with "maximizing the inner / outer contact area" and "minimizing the pull-out force" as optimization objectives. Since this embodiment has few parameters and a small parameter selection range, a traversal solution method is used to solve the normalized optimization function to obtain the global optimal solution (i.e., taking values ​​within the manufacturing precision range, calculating all parameter combinations, and selecting the optimal solution). The variable value range is... l ∈[0.02,1]mm, θ∈[2.5°,22.5°].

[0056] The optimal parameters were obtained through optimization. l =0.6mm, θ=12.5°. Substituting this dimension combination into the parametric command stream, simulation calculations were performed to obtain the mechanical properties of the optimal solution. The results were then compared with the original dimensions to obtain a comparison table, as shown in Table 4. Table 4 Specifically, in step S4, the spring wire 2 of the oblique crown spring is divided into a first part 3 and a second part 4, wherein the first part 3 is the middle vertical contact part, and the two sides are the second parts 4; the ring 1 of the oblique crown spring is divided into several third parts 5 and fourth parts 6, wherein the third part 5 is connected to the spring wire 2 and is provided with a chamfer; the first part 3, the second part 4, the third part 5 and the fourth part 6 are all divided into hexahedral mapping common node meshes; the part of the pin hole that contacts the oblique crown spring is cut and divided into hexahedral mapping meshes.

[0057] Specifically, in step S8, the simulation results of the optimized target obtained from the simulation experiment are compared with the calculation results after substituting them into the regression equation, and the relative error is calculated. Judgment based on relative error results: The relative error is less than 10%, indicating that the final optimization result is reliable. If the relative error is ≥10%, the prediction model needs to be adjusted.

[0058] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0059] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for structural design and modeling of a high-current connector with a slanted crown spring, characterized in that, Includes the following steps: S1. Select the structural parameters of the oblique crown spring as design variables and design an orthogonal experimental table; S2, Use 3D modeling software to draw the model of the oblique crown spring and its matching pins and sockets; S3 uses the APDL language to perform geometric meshing of the model, confirm material properties, and define element types; S4, mesh the geometry to form a finite element model; S5 automatically defines contact pairs, applies loads, defines solvers, and solves based on the APDL language. S6, Design optimization objectives, write post-processing programs and extract calculations; S7, Establish a regression prediction model for the optimization objective; S8, Design simulation experiments to verify the accuracy of the regression prediction model; S9. Establish a multi-objective optimization function and combine it with the optimization algorithm to obtain the optimal combination of design variables.

2. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 1, characterized in that: Select the length of the vertical contact portion in the middle of the oblique crown spring. l As design variable one, the angle θ between the center of the middle contact part and the center of the root of the spring wire (2) is selected as design variable two; design variable one and design variable two are each given 5 values ​​and form an orthogonal experimental table.

3. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 1, characterized in that: The spring wire (2) of the oblique crown spring is divided into a first part (3) and a second part (4), wherein the first part (3) is the middle vertical contact part, and the two sides are the second part (4); the ring (1) of the oblique crown spring is divided into several third parts (5) and fourth parts (6), wherein the third part (5) is connected to the spring wire (2) and is chamfered; the first part (3), the second part (4), the third part (5) and the fourth part (6) are all divided into hexahedral mapping common node meshes; the part of the pin hole that contacts the oblique crown spring is cut and divided into hexahedral mapping meshes.

4. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 3, characterized in that: When dividing the first part (3) into meshes, the number of mesh layers in the thickness direction is specified by the LESIZE command.

5. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 3, characterized in that: When meshing the third part (5), use the LESIZE command to increase the number of meshes in the chamfered area.

6. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 1, characterized in that: The optimization targets include the contact area between the pin and the pin surface after insertion, the contact area between the pin and the inner surface of the oblique crown spring after insertion, the contact area between the inner surface of the socket and the outer surface of the oblique crown spring, the stable insertion force, and the pull-out force values.

7. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 1, characterized in that: The parameter combinations used in the simulation experiment should be parameter combinations within the parameter range other than those used in orthogonal experiments.

8. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 1, characterized in that: In step S8, the simulation results of the optimized target obtained from the simulation experiment are compared with the calculation results after substituting them into the regression equation, and the relative error is calculated. Judgment based on relative error results: The relative error is less than 10%, indicating that the final optimization result is reliable. If the relative error is ≥10%, the prediction model needs to be adjusted.

9. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 1, characterized in that: In step S9, the optimal parameter combination solution is obtained based on the genetic optimization algorithm.

10. The structural design and modeling method for a high-current connector with a slanted crown spring according to claim 1, characterized in that: In step S9, the optimal combination of design variables is obtained, the optimal parameter combination solution is verified by simulation, and the simulation results are compared and verified with the complete experimental combination.

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