A method, system and device for opening a trailer hook cap simulation, and a storage medium

Abstract

The application discloses a trailer hook plug cover opening simulation method, system, device and storage medium, and the method comprises the steps of establishing a finite element model containing a trailer hook plug cover and its counterpart; setting boundary constraint conditions, wherein the contact part of the trailer hook plug cover and the counterpart is limited to separate in the normal direction and is allowed to slide in the tangential direction, and the rotating part of the trailer hook plug cover is limited to rotate only around its axis; applying a load simulating the opening operation on the finite element model, performing finite element calculation to obtain an opening force; if the opening force does not meet a preset target value, adjusting the design parameters of the trailer hook plug cover and re-performing the finite element calculation until the opening force meets the preset target value. Through specific contact attributes and single-degree-of-freedom constraints, the sliding and rotating movements of the clamping foot are accurately simulated, and the iterative optimization process is combined, so that the problems of low prediction accuracy and motion simulation distortion caused by the simplification of the simulation boundary in the prior art are solved.

Description

Technical Field

[0001] This application relates to the field of automotive exterior design technology, specifically to a method, system, device, and storage medium for simulating the opening of a trailer hitch plug. Background Technology

[0002] Trailer hook caps are an important component of automotive exterior parts, typically installed at the trailer hook interface on the front and rear bumpers. The opening force design of the trailer hook cap is a key factor affecting user experience. Excessive opening force makes operation difficult, especially in low temperatures where the plastic becomes brittle and hard, potentially preventing it from opening. Insufficient opening force, on the other hand, may cause the trailer hook cap to open unexpectedly or detach due to vibrations during vehicle operation, posing a safety hazard.

[0003] Existing trailer hook cover design methods mainly rely on designers' empirical formulas or simple mechanical balance calculations (such as torque balance formulas), however, they have the following drawbacks: (1) Empirical formulas usually treat the trailer hook plug as a rigid body, ignoring the elastic and plastic deformation of the plastic material during the stress process, resulting in a large deviation between the calculation results and the actual working conditions. Secondly, the traditional verification method requires a long cycle of "design-mold opening-trial molding-testing-mold repair". Once the physical test finds that the opening force is not up to standard or the clamping foot is broken, the mold needs to be modified, which not only increases the R&D cost, but also seriously delays the project development progress. Finally, the existing methods lack in-depth analysis of the quantitative relationship between key structural parameters (such as clamping amount, clamping angle, cantilever length, rotation axis position, etc.) and opening force and stress, making it difficult to determine the optimal parameter combination in the early stage of design.

[0004] (2) Existing simulation analysis methods often oversimplify the boundary conditions when dealing with parts with snap-fit ​​and rotation structures. For example, for the contact relationship between the snap-fit ​​foot and the counter, binding constraints or simple frictional contact are often used, which cannot accurately simulate the sliding disengagement behavior of the snap-fit ​​foot during the opening process; for rotating shafts, a real shaft part model is often built, which leads to difficulty in contact convergence and low computational efficiency. Summary of the Invention

[0005] This application provides a simulation method, system, device, and storage medium for opening trailer hook plugs, which can solve the technical problems in the prior art where the design of the opening force of the trailer hook plug relies on empirical formulas, resulting in low prediction accuracy, and the simplified boundary condition settings of the simulation method make it difficult to effectively and accurately simulate the sliding and rotational motion of the locking foot.

[0006] In a first aspect, embodiments of this application provide a simulation method for opening a trailer hook plug, comprising: Establish a finite element model of the trailer hook plug and its mating components; Set boundary constraints and apply fixed constraints to the contact component, and then apply a load to the finite element model to simulate the opening operation; wherein, the boundary constraints include: setting the contact portion between the trailer hook plug and the contact component to allow normal separation and tangential relative sliding, and limiting the rotating portion of the trailer hook plug to rotate about its axis. Perform finite element analysis and obtain the opening force and stress deformation data of the trailer hook plug based on the calculation results; compare the opening force with the preset target value; if the opening force does not meet the preset target value, adjust the design parameters of the trailer hook plug and re-perform the finite element analysis until the opening force meets the preset target value.

[0007] Preferably, a finite element model is established including the trailer hook plug and its mating components, specifically including: Acquire the three-dimensional geometric data of the trailer hook plug and its components, and discretize them into meshes using solid elements or shell elements respectively to generate an initial finite element model; The initial finite element model is divided into critical stress regions and non-critical force transmission regions; the critical stress regions include at least the root of the hook cover and the contact and mating area with the other component. A first unit density level is assigned to the critical stress region, and a second unit density level is assigned to the non-critical region, wherein the average unit size of the first density level is smaller than that of the second density level. The node positions of the initial finite element model are mapped and fitted to the surface of the three-dimensional geometric data, and a normal fit tolerance threshold between the nodes and the geometric surface is set so that the geometric deviation of the key stress region converges within the threshold.

[0008] Preferably, the mesh size of the critical stress region is 0.3mm to 1.0mm, and the normal fit tolerance threshold between the node and the geometric surface is not greater than 0.03mm; The finite element model is assigned material properties, wherein the trailer hook plug corresponds to a plastic material, and the hand component corresponds to a rigid body material or a metal material.

[0009] Preferably, the plastic material is a modified polypropylene material with an elastic modulus of 1400MPa to 2200MPa.

[0010] Preferably, the specific implementation method that restricts the normal separation of the contact area between the trailer hook plug and the contact component, while allowing tangential relative sliding, is as follows: A contact pair is established between the latching surface of the trailer hook plug and the mounting surface of the opposing component, and the contact pair is given a sliding contact property; wherein, the latching surface is constrained to slide tangentially along the surface of the opposing component, and relative displacement between the two is allowed in the normal direction.

[0011] Preferably, the specific steps for limiting the rotating part of the trailer hook plug to rotate about its axis include: A reference point is created at the design rotation center of the trailer hook plug, and a coupling constraint is established between the reference point and the inner surface of the mounting hole on the back of the trailer hook plug. The five degrees of freedom of the reference point, excluding the rotational degree of freedom about the axis, are restricted to form a single degree of freedom constraint that retains only one rotational degree of freedom.

[0012] Preferably, before establishing a coupling constraint between the reference point and the inner surface of the mounting hole on the back of the trailer hook plug, the method further includes: The two cylindrical surfaces corresponding to the rotating shaft feature of the trailer hook plug are merged into a single virtual rotating shaft feature; Using the virtual rotation axis feature as a reference, a reference point is created at the design rotation center, and a kinematic coupling relationship is established between the reference point and the virtual rotation axis feature.

[0013] Preferably, the load simulating the opening operation is applied to the finite element model, specifically including: Based on the projected front view of the trailer hook plug, the finger pressing area is defined; The finger pressing area is mapped onto the surface of the finite element model, and a vertically downward displacement load or force load is applied to the mapped area. At the same time, the load application area is set to simulate the effect of real finger contact.

[0014] Preferably, adjusting the design parameters of the trailer hook plug includes: Based on the calculation results, determine the direction and amount of deviation between the current opening force and the preset target value; Based on the deviation direction and deviation amount, and combined with the stress distribution cloud map and deformation state in the calculation results, the parameters to be adjusted and their adjustment directions are selected from the structural parameters of the trailer hook plug and the arrangement position of the rotating shaft. Modify the values ​​of the parameters to be adjusted according to the adjustment direction, and update the finite element model with the modified parameter values ​​for re-execution of the finite element calculation.

[0015] Preferably, the design parameters include structural parameters and layout location; Adjusting the design parameters of the trailer hook plug includes: The structural parameters include the snap-fit ​​amount, snap-fit ​​angle, and cantilever length; the arrangement position is characterized by the rotation axis position ratio. The latching distance is the overlap distance between the inner end face of the latching hook and the locking surface of the counter-clamp when the trailer hitch cover is fully closed; the latching angle is defined as the angle between the locking surface of the latching hook and a plane perpendicular to the unlocking direction; the cantilever length is defined as the straight-line distance from the root of the latching foot to the top of the latching hook. The rotation axis position ratio is defined as the ratio of the distance from the snap-fit ​​point to the rotation center to the total lever arm length from the force point of the trailer hook plug to the rotation center.

[0016] Preferably, based on the deviation direction and deviation amount, and in conjunction with the stress distribution cloud map and deformation state in the calculation results, the parameter to be adjusted and its adjustment direction are selected from the structural parameters and the rotation axis arrangement position, specifically including: When the opening force is greater than the preset target value and the stress at the root of the clamping foot exceeds the material yield strength, the parameter to be adjusted is selected as reducing the clamping amount and / or reducing the clamping angle, and the corresponding parameter reduction is determined as the adjustment direction. When the opening force is greater than the preset target value and the deformation at the foot hook exceeds the preset deformation threshold, the parameter to be adjusted is to increase the cantilever length, and the direction of adjustment is to increase the cantilever length. When the opening force is less than the preset target value and the stress at the root of the clamping foot is lower than the set ratio of the material yield strength, the parameter to be adjusted is selected as increasing the clamping amount and / or increasing the clamping angle, and the corresponding parameter is determined as the adjustment direction. When the opening force is less than the preset target value and the deformation at the foot hook is less than the preset deformation threshold, the reduction of the cantilever length is selected as the parameter to be adjusted, and the reduction of the cantilever length is determined as the adjustment direction.

[0017] Preferably, based on the deviation direction and deviation amount, and combined with the stress distribution cloud map and deformation state in the calculation results, the parameter to be adjusted and its adjustment direction are selected from the structural parameters and the rotation axis arrangement position, further comprising: When it is determined from the stress distribution cloud map that there is stress concentration in the area near the rotating shaft, and the deviation of the opening force from the preset target value exceeds the preset deviation threshold, the rotating shaft position ratio is selected as the parameter to be adjusted. When the opening force is greater than the preset target value, the rotation axis position ratio will be reduced to determine the adjustment direction; when the opening force is less than the preset target value, the rotation axis position ratio will be increased to determine the adjustment direction.

[0018] Secondly, this application provides a trailer hook plug opening simulation system, which includes: The model building module is used to create a finite element model of the trailer hook plug and its mating components. A boundary setting module is used to set boundary constraint conditions and apply fixed constraints to the opponent component; wherein, the boundary constraint conditions include a sliding constraint that sets the contact parts of the trailer hook plug and the opponent component to be normally separated and allows tangential relative sliding, and a single-degree-of-freedom constraint that limits the rotating part of the trailer hook plug to rotating about its axis. A load application module is used to apply loads simulating the opening operation onto the finite element model; The simulation calculation module is used to perform finite element calculations and obtain the opening force of the trailer hook plug based on the calculation results; The parameter optimization module is used to compare the opening force with the preset target value. If the opening force does not meet the preset target value, the design parameters of the trailer hook plug are adjusted and the finite element calculation is re-executed until the opening force meets the preset target value.

[0019] Thirdly, this application provides a trailer hook plug opening simulation device, which includes a processor, a memory, and a trailer hook plug opening simulation program stored in the memory and executable by the processor. When the trailer hook plug opening simulation program is executed by the processor, it implements the steps of a trailer hook plug opening simulation method.

[0020] Fourthly, this application provides a computer-readable storage medium storing a trailer hook plug opening simulation program, wherein when the trailer hook plug opening simulation program is executed by a processor, it implements the steps of a trailer hook plug opening simulation method.

[0021] The beneficial effects of the technical solutions provided in this application include: By establishing a finite element model including the contact parts and assigning material physical properties, this method overcomes the shortcomings of existing technologies that rely on empirical formulas to treat trailer hook covers as rigid bodies and ignore material deformation, significantly improving the accuracy of opening force prediction. To address the problem of motion simulation distortion caused by simplified boundary conditions, the method restricts normal separation of the contact area while allowing tangential relative sliding, accurately reproducing the physical mechanism of the latch sliding out along the inclined plane, ensuring the accuracy of peak opening force extraction. Simultaneously, it stipulates that rotating parts can only rotate around their axis, replacing complex axial contact with single-degree-of-freedom constraints, ensuring the realism of rotational motion while avoiding calculation non-convergence. Furthermore, through an iterative step of adjusting parameters and recalculating when the opening force does not meet the target value, an efficient closed-loop optimization process based on simulation feedback is established, enabling rapid automatic optimization of design parameters. Moreover, the above features synergistically form a complete technical solution, not only solving the technical problems of low simulation accuracy and inaccurate motion simulation but also significantly reducing the cost of physical trial and error, ensuring the reliability and effectiveness of product design, significantly and effectively solving the technical problems pointed out in this application, and providing a high-precision, low-cost, and reliable simulation solution for automotive exterior part design. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the simulation method for opening the trailer hook plug cover in this application; Figure 2 This is a schematic diagram of the structure of the trailer hook plug in this application; Figure 3 A schematic diagram showing the design parameters of the trailer hook plug in this application; Figure 4 The stress cloud diagram output from the simulation analysis of the trailer hook plug in this application; Figure 5 This is a schematic diagram comparing the contact states of the clamping foot and the hand component under different loads during the simulation of opening the trailer hook plug cover in an embodiment of this application. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort should fall within the scope of protection of the present application.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] In this application, the terms "upstream", "downstream", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0026] Example 1 This embodiment provides a simulation analysis method for the opening force of a trailer hitch cap. This method is applied in the design phase of automotive exterior parts, aiming to determine the key structural parameters of the trailer hitch cap by replacing physical trial and error with virtual simulation. By establishing a high-precision finite element model and setting boundary conditions that conform to real-world physical conditions, this method effectively solves the problems of simulation model distortion, calculation non-convergence, and inaccurate prediction of opening force in existing technologies, thereby significantly shortening the development cycle and reducing mold modification costs. Figure 1 As shown, the method includes the following steps: Step S1: Geometric cleanup and finite element model construction including trailer hook plug and its mating components.

[0027] Step S2: Define boundary constraints and connection relationships; that is, set boundary constraints, apply fixed constraints to the hand component, and then apply loads to simulate the opening operation on the finite element model; wherein, the boundary constraints include: setting the contact parts between the trailer hook plug and the hand component to allow normal separation and tangential relative sliding, and limiting the rotating parts of the trailer hook plug to rotate about its axis. Step S3: Definition and initialization of design parameters; Step S4: Simulation calculation and result evaluation; that is, perform finite element calculation and obtain the opening force and stress deformation data of the trailer hook plug based on the calculation results; Step S5: Parameter Iterative Optimization; that is, compare the opening force with the preset target value. If the opening force does not meet the preset target value, adjust the design parameters of the trailer hook plug and re-execute the finite element calculation until the opening force meets the preset target value.

[0028] Specifically, it is as follows: Step S1 directly determines the reliability of the calculation results, and includes: Step S100, Data Acquisition and Preprocessing: Acquire the 3D geometric data of the trailer hook plug and its counterpart (i.e., the vehicle body mounting bracket). The data format is typically CATIA, UG, or STEP. (See reference...) Figure 2 As shown, the locking foot is F, and the rotating part is E; Since CAD design data often contains a large number of features used for aesthetic purposes but with little impact on structural stiffness (such as decorative textures, small chamfers, brand logo grooves, etc.), directly meshing will lead to a surge in the number of elements and easily produce malformed elements, affecting computational convergence.

[0029] Therefore, geometric cleanup of the CAD data is necessary. Specific cleanup strategies include: deleting holes, slots, and bosses smaller than half the mesh size; simplifying decorative chamfers in non-load-bearing areas to right angles or large-radius fillets; and retaining structural chamfers in stress concentration areas (such as the base of foot catches). These cleanup strategies eliminate interference from irrelevant features in mesh generation, ensuring the quality of subsequent mesh generation and laying the foundation for convergence in simulation calculations.

[0030] Step S101, Mesh generation strategy: Use solid elements or shell elements to discretize the trailer hook plug and the hand parts to generate an initial finite element model.

[0031] The initial finite element model is divided into critical stress regions and non-critical force transmission regions; the critical stress regions include at least the root of the hook cover and the contact and mating area with the other component. A first element density level is assigned to critical stress regions, and a second element density level is assigned to non-critical regions, with the average element size of the first density level being smaller than that of the second density level. The mesh size of the critical stress regions is controlled between 0.3 mm and 1.0 mm, preferably 0.5 mm in this embodiment. The normal fit tolerance threshold between nodes and geometric surfaces is no greater than 0.03 mm. The node positions of the initial finite element model are mapped and fitted to the surfaces of the 3D geometric data, and a normal fit tolerance threshold is set between the nodes and the geometric surfaces to ensure that the geometric deviations in key stress areas converge within this threshold. By employing a differentiated mesh density strategy, the computational accuracy of stress concentration areas (foot roots) is guaranteed while the overall model size is controlled, significantly improving the solution speed. Simultaneously, strict fit tolerance control ensures a high degree of consistency between the finite element model and the actual geometry, reducing computational deviations caused by geometric discretization errors.

[0032] Step S102, Assigning Material Properties: The finite element model is assigned material properties, with the trailer hook plug corresponding to a plastic material and the hand component to a rigid body or metal material. The plastic material is a modified polypropylene with an elastic modulus of 1400MPa to 2200MPa. Density, Poisson's ratio, and yield strength are also assigned. The hand component is treated as a rigid body or assigned high-strength steel properties. By assigning realistic material physical properties, the simulation model can reflect the elastic deformation and plastic yielding behavior of the material under actual stress, ensuring that the stress calculation results match the actual part performance and providing a reliable basis for subsequent evaluation of part strength.

[0033] Step S2: Define boundary constraints and connection relationships. This step is crucial for simulation accuracy. By simulating realistic contact separation behavior and rotational degrees of freedom, it solves the technical problems in traditional simulations where overly rigid constraints prevent the simulation of the opening process, or overly loose constraints lead to computational divergence. Specifically, it includes: Step S200: Definition of contact surface constraint: Set the normal separation of the contact area between the trailer hook plug and the counterslip, while allowing tangential relative sliding. Here, "setting normal separation" means that in the locked state without applying an opening load, the latch and the counterslip should remain in contact and not separate; while after applying an opening load, normal separation between the two is allowed to achieve opening.

[0034] The specific implementation method is as follows: a contact pair is established between the locking surface of the trailer hook plug and the mounting surface of the counterpart, and the contact pair is given a sliding contact property. The locking surface is constrained to slide tangentially along the surface of the counterpart, and relative displacement between the two is allowed in the normal direction (meaning that the contact penetration is zero and separation is allowed under load).

[0035] Specific settings include: normal behavior set to "Hard Contact," allowing separation after contact; tangential behavior set to "frictionless sliding" or "low friction coefficient sliding (μ=0.1)." Setting the friction coefficient too high will result in an excessively large simulated opening force; setting it to "Tie" will prevent the simulation of the opening process.

[0036] By setting the contact attributes as described above, the physical phenomenon of the locking pin sliding along the inclined plane and eventually disengaging during the opening process is accurately simulated, avoiding the shortcomings of traditional binding constraints in simulating the separation process, and making it possible to extract the peak value of the opening force.

[0037] Step S201: Virtual Rotation Axis Construction (Degree of Freedom Constraint): The rotating parts of the trailer hook plug are restricted to rotating about its axis. Specific steps include: Create a reference point at the design rotation center of the trailer hook plug and establish a coupling constraint between this reference point and the inner surface of the mounting hole on the back of the trailer hook plug.

[0038] Before establishing coupling constraints between the reference point and the inner surface of the mounting hole on the back of the trailer hook plug, the process also includes: merging the two cylindrical surfaces corresponding to the rotation axis feature of the trailer hook plug into a virtual rotation axis feature; using the virtual rotation axis feature as a reference, creating a reference point at the design rotation center, and establishing the kinematic coupling relationship between the reference point and the virtual rotation axis feature.

[0039] The five degrees of freedom of this reference point, excluding rotation around the axis, are restricted to form a single-degree-of-freedom constraint retaining only one rotational degree of freedom. This simulates the single-degree-of-freedom motion characteristics of a trailer hook plug rotating around an axis, eliminating the convergence difficulties caused by mesh contact of real shaft parts.

[0040] By employing virtual rotating axis technology, the complex contact nonlinearity problems caused by establishing a real shaft part model are avoided, the number of calculation equations is greatly reduced, and the convergence speed and stability of simulation calculations are significantly improved.

[0041] Step S202: Define the load application area, specifically including: Based on the projected front view of the trailer hook plug, the finger pressing area is defined. This area is then mapped onto the surface of the finite element model, and a vertically downward displacement load or force load is applied within the mapped area. Simultaneously, the load application area is set to simulate the effect of real finger contact. By simulating the real finger pressing area and load type, the loading conditions are made closer to the actual user operation scenario, improving the reference value of the simulation results for ergonomic evaluation.

[0042] Step S3: Definition and Initialization of Design Parameters. Before simulation, four key structural parameters affecting the opening force need to be identified. This step quantifies the geometric features affecting the opening force into specific parameters, providing clear variable targets for subsequent iterative optimization and avoiding blind adjustments. (Reference) Figure 3 As shown, the key structural parameters include: Interlocking A: The overlap distance between the inner end face of the hook and the locking surface of the counter-clamping part when the trailer hook plug is fully closed.

[0043] Engagement angle B: defined as the angle between the locking surface of the locking hook and the plane perpendicular to the direction of unlocking movement.

[0044] Cantilever length C: Defined as the straight-line distance from the base of the clamp foot to the tip of the clamp foot hook.

[0045] The arrangement position is the rotation axis position ratio D / L. The rotation axis position ratio D / L is defined as the ratio of the distance D from the snap-fit ​​point to the rotation center to the total lever arm length L from the force point of the trailer hook cover to the rotation center.

[0046] In this embodiment, the initial setting range is as follows: the snap-fit ​​amount A is 1.0mm to 1.5mm, the snap-fit ​​angle B is 20 degrees to 35 degrees, the cantilever length C is 5mm to 8mm, and the rotation axis position ratio D / L is 1 / 3 to 1 / 2.

[0047] Step S4: Simulation calculation and result evaluation, i.e., performing finite element calculation and obtaining the opening force and stress deformation data of the trailer hook plug based on the calculation results. The calculation results are referenced. Figure 4 As shown. This step, through multi-dimensional output (force, stress, deformation), achieves simultaneous evaluation of the product's functional performance (opening force) and structural strength (stress), ensuring the comprehensive reliability of the design scheme. Specifically, it includes: Step S400: Fix the mounting of the opposing component (constraining all degrees of freedom), and apply a vertically downward displacement load to the load application surface defined in step S2. Perform the calculation using a nonlinear solver (such as Abaqus / Standard or Ansys StaticStructural). Due to the large contact deformation involved, the large deformation switch (LargeDeflection / Nlgeom) needs to be turned on.

[0048] Step S401: The output results include: opening force-displacement curve (the peak value is extracted as the opening force), stress contour map, and strain contour map.

[0049] Step S402: Evaluation criteria: The target opening force is 40N to 60N (preset target value); the safety factor is that the maximum stress of the clamping foot is less than 80% of the material yield strength.

[0050] Step S5: Parameter iterative optimization, refer to Figure 5 As shown, this involves adjusting the design parameters of the trailer hook plug and re-performing the finite element calculation. This step, by establishing a closed-loop optimization logic based on simulation feedback, achieves automatic optimization of design parameters, overcoming the problems of long cycles and high costs caused by traditional trial-and-error methods that rely on experience. This ensures that the final design scheme meets the opening force requirements while also taking into account structural strength.

[0051] Design parameters include structural parameters and layout; adjustments to the trailer hook cover design parameters specifically include: Based on the calculation results, determine the direction and amount of deviation between the current opening force and the preset target value; based on the direction and amount of deviation, and combined with the stress distribution cloud map and deformation state in the calculation results, select the parameters to be adjusted and their adjustment direction from the structural parameters of the trailer hook plug and the arrangement position of the rotating shaft; Among them, the stress distribution cloud map is used to locate the stress concentration area to determine whether the root of the clamp or the hook of the clamp is the part to be adjusted, and the deformation state is used to determine whether the bending deformation of the clamp or the torsional deformation of the rotating shaft is a factor to be adjusted.

[0052] Modify the values ​​of the parameters to be adjusted according to the adjustment direction, and update the finite element model with the modified parameter values ​​for re-execution of the finite element calculation.

[0053] The specific adjustment logic mentioned above includes: When the opening force is greater than the preset target value and the stress at the root of the clamp exceeds the yield strength of the material, select the reduction of clamping amount A and / or reduction of clamping angle B as the parameters to be adjusted, and determine the reduction of the corresponding parameters as the adjustment direction.

[0054] When the opening force is greater than the preset target value and the deformation at the foot hook exceeds the preset deformation threshold, the increased cantilever length C is selected as the parameter to be adjusted, and the increased cantilever length C is determined as the adjustment direction.

[0055] When the opening force is less than the preset target value and the stress at the root of the clamp foot is lower than the set ratio of the material yield strength, select increasing the clamping amount A and / or increasing the clamping angle B as the parameters to be adjusted, and determine the direction of adjustment by increasing the corresponding parameters.

[0056] When the opening force is less than the preset target value and the deformation at the foot hook is less than the preset deformation threshold, the reduction of cantilever length C is selected as the parameter to be adjusted, and the reduction of cantilever length C is determined as the adjustment direction.

[0057] The adjustment logic for the rotation axis position ratio includes: When the stress distribution cloud map indicates that there is stress concentration in the area near the rotating shaft, and the deviation of the opening force from the preset target value exceeds the preset deviation threshold, the rotating shaft position ratio D / L is selected as the parameter to be adjusted.

[0058] Specifically, when the opening force exceeds the preset target value, the adjustment direction is determined by decreasing the rotation axis position ratio; when the opening force is less than the preset target value, the adjustment direction is determined by increasing the rotation axis position ratio. This is based on the lever principle, where decreasing the lever arm ratio reduces the opening force.

[0059] The optimization process continues until the opening force meets the preset target value.

[0060] In summary, the simulation analysis method provided in this embodiment, through the coordinated operation of steps S1 to S5, achieves a closed-loop process from model construction, boundary simulation, parameter definition to iterative optimization. It can accurately predict the opening force and stress state of the trailer hook plug before mold opening, effectively avoiding later mold repairs due to design flaws; by replacing physical trial and error with virtual iteration, it significantly shortens the product development cycle and reduces R&D costs; simultaneously, the optimization logic based on stress cloud diagrams and deformation states ensures that the final product not only meets the requirements for opening force feel but also possesses sufficient structural strength and durability, improving the overall product quality and user satisfaction.

[0061] Example 2 To demonstrate that the parameter range proposed in Example 1 was not arbitrarily chosen, but rather an optimal range verified by simulation, multiple sets of comparative simulation tests were conducted. The test conditions were the same as in Example 1, with the material fixed as PP+EPDM-TD20 and the target opening force as 50N±10N. See Table 1 below for a comparison of the influence of key parameters on opening force and stress.

[0062]

[0063] Table 1: Comparison of the Influence of Key Parameters on Opening Force and Stress Data analysis conclusions and mechanism explanation: Sensitivity of the locking amount A: As shown in groups 1, 2, and 3, the opening force and the locking amount are approximately linearly positively correlated. When A decreases from 1.2 mm to 0.5 mm, the opening force decreases by approximately 48%. This proves that 1.0 mm is the lower limit for ensuring basic self-locking force. When A increases to 2.0 mm, the stress increases significantly, indicating that excessive interference can lead to residual assembly stress, which may cause creep relaxation in the long term. Therefore, 1.0-1.5 mm is the optimal range for balancing self-locking performance and assembly performance.

[0064] The nonlinear effect of the engagement angle B: As shown in groups 1, 4, and 5, the influence of angle B on the opening force has a nonlinear characteristic. When the angle is too small (15°), although the stress is not high, the horizontal component force is insufficient to resist vibration; when the angle is too large (45°), the opening force increases sharply. Around 30° is a critical point, at which the friction angle and pressure angle are optimally matched.

[0065] The stiffness effect of cantilever length C: As shown in groups 1, 6, and 7, cantilever length has the greatest impact on stress. In group 6, when C=3.0mm, the stress reaches as high as 41.5MPa, far exceeding the yield strength of 25MPa, indicating that short cantilevers are extremely prone to fracture. Although the stress in group 7 is low, a length of 10mm is difficult to arrange in the compact trailer hitch area. 5-8mm represents a trade-off between stress safety and spatial layout.

[0066] Optimization of the rotation axis position ratio D / L: As shown in groups 1, 8, and 9, the D / L ratio directly amplifies or reduces the applied force. A ratio of around 0.4 maximizes the transmission efficiency of pressing force and card contact force.

[0067] To further verify the accuracy of the simulation, the inventors made a physical sample of the parameters in group 1 and tested its opening force on a universal testing machine.

[0068] Simulation result: 48.5N Physical test results: 46.0N, 49.5N, 51.0N (average value 48.8N); Error analysis: The error is less than 1%, proving that this simulation method has a very high confidence level and can be used as a basis for design decisions.

[0069] Example 3 Robust design considering manufacturing tolerances and environmental factors; in actual injection molding production and throughout the entire life cycle of automobiles, part dimensions and material properties are not constant values.

[0070] Therefore, the tolerance of the snap-fit ​​amount A is set to ±0.05mm, and the fluctuation range of the material's elastic modulus is set to ±10%. The worst-case analysis method is used for simulation calculation.

[0071] The most challenging opening condition was set: the contact depth A was set to the upper limit of 1.55mm, the material modulus to the upper limit of 2200MPa, and the temperature to -40℃. Simulation results showed that the opening force was 58N, which is still less than the upper limit of 60N, thus meeting the requirements.

[0072] The optimal release condition was set as follows: the clamping depth A was set to the lower limit of 0.95mm, the material modulus to the lower limit of 1400MPa, and the temperature to 80℃. Simulation results showed that the opening force was 42N, which is still greater than the lower limit of 40N, thus meeting the requirements.

[0073] Example 4 A simulation system for opening a trailer hook plug is provided, comprising: The model building module is used to create a finite element model of the trailer hook plug and its mating components. The boundary setting module is used to set boundary constraints and apply fixed constraints to the contact parts; wherein, the boundary constraints include a sliding constraint that sets the contact parts of the trailer hook plug and the contact parts to be normally separated and allows tangential relative sliding, and a single-degree-of-freedom constraint that limits the rotating parts of the trailer hook plug to rotating about its axis. The load application module is used to apply loads to the finite element model to simulate the opening operation. The simulation calculation module is used to perform finite element calculations and obtain the opening force of the trailer hook plug based on the calculation results; The parameter optimization module is used to compare the opening force with the preset target value. If the opening force does not meet the preset target value, the design parameters of the trailer hook plug are adjusted and the finite element calculation is re-executed until the opening force meets the preset target value.

[0074] The methodology of this application is not limited to trailer hook plugs, but can also be extended to other products with similar "press + snap + rotate" opening logic. This demonstrates the versatility of the technical solution presented in this application.

[0075] For example, other exterior automotive parts can be: Charging port cover: Electric vehicle charging port covers also typically use a press-to-open structure. Their snap-on design is similar to that of trailer hook covers, and the parameter range and optimization process of this method can be directly applied.

[0076] Fuel tank cap: The unlocking mechanism for the fuel tank cap of a traditional gasoline vehicle.

[0077] Glove box button: The push-to-pop mechanism of the glove box in the vehicle needs to take into account the internal space constraints. The compact design concept of this method (such as virtual axis) is particularly suitable.

[0078] Cup holder cover: Dust cover for the cup holder in the center armrest box.

[0079] Furthermore, this application provides solutions to the following problems that may arise during the long-term implementation of this method: If the simulation fails to converge, it indicates that the contact settings are too stiff, the mesh is distorted, or the load step is too large. Solutions include: refining the contact area mesh, using automatic time stepping, increasing the damping coefficient, and checking if the initial interference is too large, causing initial penetration.

[0080] If the simulated force value deviates significantly from the measured value, it indicates that the material constitutive model is inaccurate, the friction coefficient is improperly set, or the boundary constraints are too strong. The solutions are: retest the material tensile curve, adjust the friction coefficient, and check whether the virtual axis constraints restrict the necessary minute translations.

[0081] Frequent breakage at the root of the gate indicates stress concentration, insufficient material toughness, and uneven wall thickness caused by the draft angle. Solutions include: increasing the root fillet radius (R-corner), optimizing the gate location to reduce weld lines in high-stress areas, and adjusting the cantilever length C.

[0082] Example 5 This application provides a trailer hook plug opening simulation device, which can be a personal computer (PC), laptop computer, server or other device with data processing capabilities.

[0083] In this embodiment of the application, the trailer hook plug opening simulation device may include a processor, a memory, a communication interface, and a communication bus.

[0084] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0085] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting internal components of the trailer hook plug opening simulation device, as well as interfaces used for interconnecting the simulation device with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0086] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0087] The processor can be a general-purpose processor, which can call the trailer hook cover opening simulation program stored in the memory and execute the trailer hook cover opening simulation method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the trailer hook cover opening simulation program is called can be referred to in the various embodiments of the trailer hook cover opening simulation method of this application, and will not be repeated here.

[0088] Example 6 This application provides a computer-readable storage medium.

[0089] The present application has a computer-readable storage medium storing a trailer hook plug opening simulation program, wherein when the trailer hook plug opening simulation program is executed by a processor, it implements the steps of the trailer hook plug opening simulation method described above.

[0090] The method implemented when the trailer hook plug opening simulation program is executed can be referred to in the various embodiments of the trailer hook plug opening simulation method of this application, and will not be repeated here.

[0091] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0092] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0093] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0094] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0095] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0096] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0097] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A simulation method for opening a trailer hook plug, characterized in that, It includes: Establish a finite element model of the trailer hook plug and its mating components; Set boundary constraints and apply fixed constraints to the contact component, and then apply a load to the finite element model to simulate the opening operation; wherein, the boundary constraints include: setting the contact portion between the trailer hook plug and the contact component to allow normal separation and tangential relative sliding, and limiting the rotating portion of the trailer hook plug to rotate about its axis. Perform finite element analysis and obtain the opening force and stress deformation data of the trailer hook plug based on the calculation results; compare the opening force with the preset target value; if the opening force does not meet the preset target value, adjust the design parameters of the trailer hook plug and re-perform the finite element analysis until the opening force meets the preset target value.

2. The simulation method for opening the trailer hook plug as described in claim 1, characterized in that, Establish a finite element model of the trailer hook plug and its mating components, specifically including: Acquire the three-dimensional geometric data of the trailer hook plug and its components, and discretize them into meshes using solid elements or shell elements respectively to generate an initial finite element model; The initial finite element model is divided into critical stress regions and non-critical force transmission regions; the critical stress regions include at least the root of the hook cover and the contact and mating area with the other component. A first unit density level is assigned to the critical stress region, and a second unit density level is assigned to the non-critical region, wherein the average unit size of the first density level is smaller than that of the second density level. The node positions of the initial finite element model are mapped and fitted to the surface of the three-dimensional geometric data, and a normal fit tolerance threshold between the nodes and the geometric surface is set so that the geometric deviation of the key stress region converges within the threshold.

3. The simulation method for opening the trailer hook plug as described in claim 2, characterized in that: The mesh size of the critical stress region is 0.3mm to 1.0mm, and the normal fit tolerance threshold between the node and the geometric surface is no greater than 0.03mm; The finite element model is assigned material properties, wherein the trailer hook plug corresponds to a plastic material, and the hand component corresponds to a rigid body material or a metal material.

4. The trailer hook plug opening simulation method as described in claim 3, characterized in that: The plastic material is a modified polypropylene material with an elastic modulus of 1400MPa to 2200MPa.

5. The simulation method for opening the trailer hook plug as described in claim 1, characterized in that, The specific implementation method that restricts the normal separation of the contact area between the trailer hook plug and the contact component, while allowing tangential relative sliding, is as follows: A contact pair is established between the latching surface of the trailer hook plug and the mounting surface of the opposing component, and the contact pair is given a sliding contact property; wherein, the latching surface is constrained to slide tangentially along the surface of the opposing component, and relative displacement between the two is allowed in the normal direction.

6. The simulation method for opening the trailer hook plug as described in claim 1 or 5, characterized in that, The specific steps for limiting the rotating part of the trailer hook plug to rotate about its axis include: A reference point is created at the design rotation center of the trailer hook plug, and a coupling constraint is established between the reference point and the inner surface of the mounting hole on the back of the trailer hook plug. The five degrees of freedom of the reference point, excluding the rotational degree of freedom about the axis, are restricted to form a single degree of freedom constraint that retains only one rotational degree of freedom.

7. The trailer hook plug opening simulation method as described in claim 6, characterized in that, Before establishing a coupling constraint between the reference point and the inner surface of the trailer hook plug mounting hole on the back of the trailer hook plug, the process further includes: The two cylindrical surfaces corresponding to the rotating shaft feature of the trailer hook plug are merged into a single virtual rotating shaft feature; Using the virtual rotation axis feature as a reference, a reference point is created at the design rotation center, and a kinematic coupling relationship is established between the reference point and the virtual rotation axis feature.

8. The simulation method for opening the trailer hook plug as described in claim 1, characterized in that, Applying loads to the finite element model to simulate the opening operation specifically includes: Based on the projected front view of the trailer hook plug, the finger pressing area is defined; The finger pressing area is mapped onto the surface of the finite element model, and a vertically downward displacement load or force load is applied to the mapped area. At the same time, the load application area is set to simulate the effect of real finger contact.

9. The simulation method for opening the trailer hook plug as described in claim 1, characterized in that, Adjusting the design parameters of the trailer hook plug includes: Based on the calculation results, determine the direction and amount of deviation between the current opening force and the preset target value; Based on the deviation direction and deviation amount, and combined with the stress distribution cloud map and deformation state in the calculation results, the parameters to be adjusted and their adjustment directions are selected from the structural parameters of the trailer hook plug and the arrangement position of the rotating shaft. Modify the values ​​of the parameters to be adjusted according to the adjustment direction, and update the finite element model with the modified parameter values ​​for re-execution of the finite element calculation.

10. The simulation method for opening the trailer hook plug as described in claim 9, characterized in that: The design parameters include structural parameters and layout location; Adjusting the design parameters of the trailer hook plug includes: The structural parameters include the snap-fit ​​amount, snap-fit ​​angle, and cantilever length; the arrangement position is characterized by the rotation axis position ratio. The latching distance is the overlap distance between the inner end face of the latching hook and the locking surface of the counter-clamp when the trailer hitch cover is fully closed; the latching angle is defined as the angle between the locking surface of the latching hook and a plane perpendicular to the unlocking direction; the cantilever length is defined as the straight-line distance from the root of the latching foot to the top of the latching hook. The rotation axis position ratio is defined as the ratio of the distance from the snap-fit ​​point to the rotation center to the total lever arm length from the force point of the trailer hook plug to the rotation center.

11. The trailer hook plug opening simulation method as described in claim 10, characterized in that, Based on the deviation direction and deviation amount, and combined with the stress distribution cloud map and deformation state in the calculation results, the parameters to be adjusted and their adjustment directions are selected from the structural parameters and the rotation axis arrangement position, specifically including: When the opening force is greater than the preset target value and the stress at the root of the clamping foot exceeds the material yield strength, the parameter to be adjusted is selected as reducing the clamping amount and / or reducing the clamping angle, and the corresponding parameter reduction is determined as the adjustment direction. When the opening force is greater than the preset target value and the deformation at the foot hook exceeds the preset deformation threshold, the parameter to be adjusted is to increase the cantilever length, and the direction of adjustment is to increase the cantilever length. When the opening force is less than the preset target value and the stress at the root of the clamping foot is lower than the set ratio of the material yield strength, the parameter to be adjusted is selected as increasing the clamping amount and / or increasing the clamping angle, and the corresponding parameter is determined as the adjustment direction. When the opening force is less than the preset target value and the deformation at the foot hook is less than the preset deformation threshold, the reduction of the cantilever length is selected as the parameter to be adjusted, and the reduction of the cantilever length is determined as the adjustment direction.

12. The trailer hook plug opening simulation method as described in claim 11, characterized in that, Based on the deviation direction and deviation amount, and combined with the stress distribution cloud map and deformation state in the calculation results, the parameters to be adjusted and their adjustment directions are selected from the structural parameters and the rotation axis arrangement position, and the method further includes: When it is determined from the stress distribution cloud map that there is stress concentration in the area near the rotating shaft, and the deviation of the opening force from the preset target value exceeds the preset deviation threshold, the rotating shaft position ratio is selected as the parameter to be adjusted. When the opening force is greater than the preset target value, the rotation axis position ratio will be reduced to determine the adjustment direction; when the opening force is less than the preset target value, the rotation axis position ratio will be increased to determine the adjustment direction.

13. A simulation system for opening a trailer hook plug, characterized in that, It includes: The model building module is used to create a finite element model of the trailer hook plug and its mating components. A boundary setting module is used to set boundary constraint conditions and apply fixed constraints to the opponent component; wherein, the boundary constraint conditions include a sliding constraint that sets the contact parts of the trailer hook plug and the opponent component to be normally separated and allows tangential relative sliding, and a single-degree-of-freedom constraint that limits the rotating part of the trailer hook plug to rotating about its axis. A load application module is used to apply loads simulating the opening operation onto the finite element model; The simulation calculation module is used to perform finite element calculations and obtain the opening force of the trailer hook plug based on the calculation results; The parameter optimization module is used to compare the opening force with the preset target value. If the opening force does not meet the preset target value, the design parameters of the trailer hook plug are adjusted and the finite element calculation is re-executed until the opening force meets the preset target value.

14. A simulation device for opening a trailer hook plug, characterized in that, The trailer hook plug opening simulation device includes a processor, a memory, and a trailer hook plug opening simulation program stored in the memory and executable by the processor, wherein when the trailer hook plug opening simulation program is executed by the processor, it implements the steps of the trailer hook plug opening simulation method as described in any one of claims 1 to 12.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a trailer hook plug opening simulation program, wherein when the trailer hook plug opening simulation program is executed by a processor, it implements the steps of the trailer hook plug opening simulation method as described in any one of claims 1 to 12.

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