Simulation method and system for side-slip working condition of rear axle with leaf spring based on CATIA software and storage medium

Abstract

The application discloses a kind of based on CATIA software's with plate spring rear axle roll condition simulation method, system and storage, mainly related to light vehicle with plate spring rear axle motion simulation field.The method includes the following steps: input vehicle parameter and roll degree value;Formula constraint is applied to the parameter using CATIA sketch, and plate spring center point trajectory is output;Roll condition simulation model is built;The input angle of roll condition is determined;Tire envelope and linkage envelope are output by model;DMU gap check is carried out according to the obtained model and envelope.The beneficial effects of the application are that the simulation of the roll condition of rear axle is realized, and the simulation of various roll angles can be carried out.

Description

Technical Field

[0001] This invention relates to the field of motion simulation of a light vehicle rear axle with leaf springs, specifically a method, system, and storage for simulating the rollover condition of a rear axle with leaf springs based on CATIA software. Background Technology

[0002] The suspension system is a general term for the devices that provide an elastic connection between the wheels (or axles) and the vehicle frame (or monocoque chassis) and are capable of transmitting loads, mitigating shocks, damping vibrations, and adjusting the vehicle's position. The primary function of the suspension is to transmit all forces and torques acting between the wheels and the frame, mitigate the impact of uneven road surfaces on the vehicle body, dampen the resulting vibrations in the load-bearing system, and ensure a smooth ride.

[0003] With the trend of lightweighting and material conservation in automobiles, new types of leaf springs, such as those with fewer leaves, variable cross-section, and gradually varying stiffness, are gradually replacing ordinary multi-leaf springs in leaf spring suspensions commonly used in light vehicles, and are widely used due to their superior performance.

[0004] In the process of developing a suspension system with leaf springs and an integral rear axle for light vehicles, the motion simulation of the rear axle previously only included horizontal jump simulation and lacked the construction of a roll condition simulation model. When outputting the tire envelope and linkage envelope, the roll condition of the rear axle had to be manually set, which was quite cumbersome. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes a simulation method, system, and storage mechanism for rear axles with leaf springs under roll conditions based on CATIA software. This allows for the creation of simulation models of roll conditions without the need for manual position input.

[0006] To achieve the above objectives, this invention employs the following technical solution, comprising the following steps: inputting vehicle model parameters and roll angle values; applying dimensional formula constraints and constraint pairs to the relevant data using CATIA sketches and outputting the trajectory line of the leaf spring center point; building a simulation model of the roll condition of the rear axle with leaf springs; determining the input angle of the roll condition of the rear axle with leaf springs; outputting the tire envelope and linkage envelope through the model; and performing DMU clearance verification based on the obtained model and envelope.

[0007] Preferably, the vehicle parameter values ​​include the hard points of the benchmark vehicle or the design vehicle, as well as the diameter of the leaf spring coil and the length of the suspension lug.

[0008] Preferably, the data includes hard points, line segments, and the trajectories of lugs, coils, main leaf springs, and the center point of the main leaf spring. Applying dimensions to the data includes hard point fixing constraints, clamping length and lug length constraints, and tangential constraints between the coil and the main leaf. The formula constraints include: angle = arc length / radius.

[0009] Preferably, the trajectory of the center point of the main leaf spring is obtained by driving the main leaf arc to jump using the radius of curvature constraint.

[0010] Preferably, the constraint pairs include: the leaf spring and the mid-plane, and the leaf spring trajectory line are fixed parts, and a fixed constraint pair is adopted; the point on the mid-plane and the point on the left side of the rear axle that coincides with the center point of the leaf spring and the Y-direction tension surface of the trajectory line are adopted as a point-on-plane constraint pair; the first auxiliary part is connected to the rear axle by a revolute joint; the second auxiliary part and the first auxiliary part are constrained by a rhombus shape and the values ​​of the upper and lower travel of the suspension are set; the second auxiliary part and the fixed part leaf spring are constrained by a planar connection; the upper part of the shock absorber and the lower part of the shock absorber are constrained by a rhombus shape; the upper part of the shock absorber and the fixed part leaf spring are constrained by a spherical surface; the lower part of the shock absorber and the rear axle with wheels are constrained by a universal connection; the constraint pairs on the right side are the same as those on the left side.

[0011] Preferably, the input angle for the roll condition is 5 degrees.

[0012] Preferably, the step of outputting the tire envelope and linkage envelope through the model specifically means outputting the tire envelope and linkage envelope under conditions such as skidding, roll, and braking through the model.

[0013] Preferably, the DMU gap verification specifically involves adjusting the coordinate values ​​of the hard points and repeating the above steps until the gap arrangement requirements of the components are met, then locking the hard points and releasing the data.

[0014] A simulation system for roll condition of a rear axle with leaf springs based on CATIA software includes a data acquisition module, a data processing module, and a data output module. The data acquisition module is used to collect and input the vehicle parameters and roll angle values ​​mentioned above. The data processing module is used to process the collected vehicle parameters and roll angle values. The data output module is used to output a simulation model of roll condition of a rear axle with leaf springs after completing the data processing.

[0015] A storage medium for simulating the rollover condition of a rear axle with leaf springs based on CATIA software stores one or more programs, which can be executed by one or more processors to implement the CATIA software-based simulation method for the rollover condition of a rear axle with leaf springs as described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] Based on previous simulation practices, this invention utilizes the CATIA software simulation module and adds auxiliary parts to transform the simulation degrees of freedom, enabling the simulation of rear axle roll conditions. It can simulate various roll angles and output position envelopes for various roll conditions, including level jump conditions, providing a design basis for DMU clearance verification of a series of vehicle models. Attached Figure Description

[0018] Figure 1 This is a skeleton diagram of the leaf spring motion model of the present invention.

[0019] Figure 2 This is a simulation model diagram of the rear axle rollover condition of the present invention.

[0020] Figure 3 This invention provides an automatic sweep output of the tire envelope map.

[0021] Figure 4 This is a diagram showing the trajectory of the center point of the leaf spring according to the present invention.

[0022] Figure 5 This is an added diagram of the constraint pairs for each part of the present invention.

[0023] Figure 6 This is a diagram of the tire envelope and shock absorber envelope of the present invention.

[0024] Figure 7 This is a diagram showing the determination of the tilt angle under the working conditions of the present invention.

[0025] Figure 8 This is a parameter input comparison diagram of the present invention.

[0026] The labels shown in the attached diagram:

[0027] 1. Wheel; 2. Leaf spring; 3. Shock absorber; 4. Second auxiliary component; 5. First auxiliary component; 6. Rear axle; 7. Hanger plate; 8. Leaf spring center trajectory point; 9. Upper limit; 10. Unloaded; 11. Rear axle midpoint; 12. Left wheel height constraint; 13. Right wheel height constraint; 14. Mid-plane; 15. Left wheel envelope; 16. Right wheel envelope; 17. Shock absorber envelope. Detailed Implementation

[0028] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0029] Example:

[0030] 1. For example Figure 8The input parameters include the leaf spring mounting hard point and hanger plate hard point, leaf spring coil diameter, etc. of the benchmark model or design model.

[0031] 2. For example Figure 3-4 As shown, constraints are applied to hard points, line segments, lugs, coils, and main leaf springs in the CATIA sketch to ensure that the arc length of the leaf spring remains constant. The trajectory of the center point of the main leaf spring is obtained by driving the curve radius constraint.

[0032] 3. For example Figure 1-2 and Figure 5 As shown, auxiliary parts are added to achieve the transformation of degrees of freedom. Height constraints are added to both sides of the left and right wheels to realize the simulation model of the roll condition. The constraint pairs are as follows:

[0033] (1) The leaf spring, the mid-plane, and the leaf spring trajectory line are fixed parts, and a fixed constraint pair is adopted;

[0034] (2) The point where the center point of the rear axle coincides with the mid-plane and the point where the left side of the rear axle coincides with the center point of the leaf spring and the Y-direction tension surface of the trajectory line adopts a point-on-surface constraint pair;

[0035] (3) The first auxiliary part is connected to the rear axle by a rotating joint to convert the change in the height degree of freedom of the left and right wheels;

[0036] (4) The second auxiliary part and the first auxiliary part adopt a diamond constraint to convert the height drive degree of freedom of the left and right wheels;

[0037] (5) The second auxiliary part and the fixed part leaf spring adopt a planar connection constraint to limit the rotation of the rear axle;

[0038] (6) The upper and lower parts of the shock absorber are constrained by a diamond shape;

[0039] (7) The upper part of the shock absorber and the leaf spring of the fixed part are constrained by a spherical surface;

[0040] (8) The lower part of the shock absorber and the rear axle with wheels adopt a universal joint constraint;

[0041] (9) The constraint pair on the right side is added in the same way as on the left side. In the diamond constraint in step (4), set the values ​​of the suspension's upward and downward travel (in this case, the upward travel is 112mm and the downward travel is 70mm).

[0042] At this point, the simulation model is complete. The model contains height constraint commands for the left and right wheels, which can realize the side tilt simulation of the rear axle at any angle within the set travel range.

[0043] 4. Determine the input angle for the roll condition;

[0044] like Figure 7As shown, based on subjective evaluation and objective testing practices, the maximum empirical angle for roll conditions is generally 5 degrees. This case is designed based on 5 degrees (at this time, the Z-axis height of the left wheel center is 112mm, and the right wheel center is 2.5mm in oscillation).

[0045] 5. For example Figure 6 As shown, the model outputs the tire envelope and linkage envelope under conditions such as horizontal jump, lateral tilt, and braking.

[0046] 6. Perform DMU gap verification based on the obtained model and envelope. If it is not feasible, adjust the hard points in time until the requirements are met.

[0047] Corresponding to the above method embodiments, this application provides a simulation system for the roll condition of a rear axle with leaf springs based on CATIA software, including a data acquisition module, a data processing module, and a data output module. The data acquisition module is used to acquire and input the vehicle parameters and roll angle values ​​mentioned above. The data processing module is used to process the acquired vehicle parameters and roll angle values. The data output module is used to output a simulation model of the roll condition of a rear axle with leaf springs after completing the data processing.

[0048] Corresponding to the above method embodiments, this application embodiment also provides a storage medium for simulating the rollover condition of a rear axle with leaf springs based on CATIA software. The storage medium stores a computer program, and when the computer program is executed by a processor, it implements the steps of the above-described external storage medium method.

[0049] This embodiment uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solution and core ideas of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A simulation method for rollover conditions of a rear axle with leaf springs based on CATIA software, characterized in that, Includes the following steps: S1 Input vehicle model parameters and roll value; S2 uses CATIA sketches to apply dimensional formula constraints and constraint pairs to the data and outputs the trajectory line of the leaf spring center point. The data includes hard points, line segments, lugs, coil lugs, the main leaf spring, and the trajectory of the main leaf spring center point. Applying dimensions to the data includes hard point fixing constraints, clamping length and lug length constraints, and tangency constraints between the coil lug and the main leaf. The formula constraints include: angle = arc length / radius; the constraint pairs include: The leaf spring, the mid-plane, and the leaf spring trajectory line are fixed parts, and fixed constraint pairs are used; The points coinciding with the center point of the rear axle and the mid-plane, and the points on the left side of the rear axle and the center point of the leaf spring, and the Y-direction tension surface of the trajectory line adopt a point-on-surface constraint pair. The first auxiliary component is connected to the rear axle by a rotary joint; The second auxiliary component and the first auxiliary component are constrained by a diamond shape, and the values ​​of the suspension's upward and downward travel are set. The second auxiliary component and the fixed component leaf spring are constrained by a planar connection. The upper and lower parts of the shock absorber are constrained by a diamond shape; The upper part of the shock absorber is constrained by a leaf spring on the fixed part using a spherical surface. The lower part of the shock absorber and the rear axle with wheels use a universal connection constraint; The constraint pairs on the right are added in the same way as on the left. S3 builds a simulation model of the rollover condition of a rear axle with leaf springs. S4 determines the input angle for the roll condition of the rear axle with leaf springs; S5 outputs the tire envelope and the linkage envelope from the model; S6 performs DMU gap verification based on the obtained model and envelope.

2. The simulation method for rollover conditions of a rear axle with leaf springs based on CATIA software according to claim 1, characterized in that, The vehicle parameters include the hard points of the benchmark or design vehicle, as well as the diameter of the leaf spring coil and the length of the suspension lug.

3. The simulation method for rollover conditions of a rear axle with leaf springs based on CATIA software according to claim 1, characterized in that, The trajectory of the center point of the main leaf spring is obtained by driving the main leaf arc to jump using the radius of curvature constraint.

4. The simulation method for rollover conditions of a rear axle with leaf springs based on CATIA software according to claim 1, characterized in that, The input angle for the roll condition is 5 degrees.

5. The simulation method for rollover conditions of a rear axle with leaf springs based on CATIA software according to claim 1, characterized in that, Specifically, the output of tire envelope and linkage envelope through the model refers to the output of tire envelope and linkage envelope under the conditions of horizontal jump, roll, and braking through the model.

6. The simulation method for rollover conditions of a rear axle with leaf springs based on CATIA software according to claim 1, characterized in that, The specific steps for DMU gap verification are to adjust the coordinate values ​​of the hard points and repeat the above steps S1-S5 until the gap arrangement requirements of the components are met, then lock the hard points and release them.

7. A simulation system for rollover conditions of a rear axle with leaf springs based on CATIA software, used to implement the method described in any one of claims 1 to 6, characterized in that, It includes a data acquisition module, a data processing module, and a data output module; The data acquisition module is used to: collect input vehicle model parameters and roll angle values; The data processing module is used to: apply dimensional formula constraints and constraint pairs to the data involved using CATIA sketches and output the trajectory line of the center point of the leaf spring; then build a simulation model of the rollover condition of the rear axle with leaf springs and determine the input angle of the rollover condition of the rear axle with leaf springs. The data output module is used to output the tire envelope and the rod system envelope, and to perform DMU clearance verification based on the obtained model and envelope.

8. A storage medium for simulating the rollover condition of a rear axle with leaf springs based on CATIA software, characterized in that, The system stores one or more programs, which can be executed by one or more processors to implement the simulation method for rollover conditions of a rear axle with leaf springs based on CATIA software as described in any one of claims 1 to 6.

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