A modeling method for simulating twist beam suspension motion

Abstract

The application relates to a modeling method for simulating the motion of a twist beam suspension, which comprises the following steps: extracting a shear center point of a twist beam cross section and other hard points of the twist beam suspension; segmenting the twist beam structure; establishing a first drive and a second drive; building a first twist beam suspension model; building a second twist beam suspension model, controlling the motion of the shear center; obtaining a motion model of the whole twist beam rear suspension; and using the motion model of the rear suspension. According to the application, the twist beam is segmented into two independent rigid bodies, the motion model of the asymmetric rear suspension is established, the motion of the twist beam suspension on one side is equivalent to the motion of an independent suspension similar to a single inclined arm type, the motion of the shear center of the twist beam is controlled on the other side through a motion constraint relationship, the motion law curves of two drives of left and right wheels are set respectively, various complex working conditions can be freely realized, and the twist beam is more closely matched with the actual motion. The method does not need to use finite element software to make the twist beam flexible, the process is simple, and the efficiency is high.

Description

Technical Field

[0001] This invention belongs to the field of passenger vehicle suspension technology, specifically relating to a modeling method for simulating the motion of a torsion beam suspension. Background Technology

[0002] Building a suspension motion model in 3D modeling software allows for motion analysis, simulating the actual operation of the product in a virtual environment, and checking and analyzing the product's positional and motion characteristics during the dynamic process. For independent suspensions, based on the motion principles of the linkage system, a suspension motion model is built by constraining the motion relationships between the linkages, simulating the suspension's motion, and then performing clearance checks and generating the envelopes of tires and various components.

[0003] As a widely used suspension type in passenger vehicles, the torsion beam suspension has advantages such as fewer parts, simple structure, small footprint, low cost, and light weight. However, unlike independent suspension where the left and right wheels move independently and do not affect each other, the left and right wheels of the torsion beam suspension influence each other during movement. Especially when there is a difference in wheel bounce, it is mainly achieved through the deformation of the central crossbeam. It is impossible to simulate the deformation state during movement in 3D modeling software, and the accuracy of the wheel motion relationship cannot be guaranteed. Therefore, in existing technologies, finite element software is typically used to flex the torsion beam, followed by tests of parallel and reverse wheel bounce. However, due to the complexity of multiple software operations, this process is cumbersome and inefficient.

[0004] Existing technology discloses a modeling method for a torsion beam suspension. This method approximates the motion of the torsion beam suspension by dividing the torsion beam into two independent rigid bodies, each rotating about the line connecting the longitudinal arm point and the shear center point as an axis. However, this method has a drawback: the shear center point of the crossbeam is static, while the shear center is calculated and extracted from the crossbeam section of the torsion beam. In actual torsion beam motion, the shear center changes with the movement of the torsion beam, resulting in a discrepancy between the modeling method and reality. Summary of the Invention

[0005] The purpose of this invention is to provide a modeling method for simulating the motion of a torsion beam suspension, solving the problem of achieving motion by closely following the torsion beam and simulating parallel and reverse wheel bounces of the torsion beam suspension within the same motion model. This invention establishes an asymmetrical rear suspension motion model by dividing the torsion beam into two independent rigid bodies. On one side, the motion of the torsion beam suspension is equivalent to an independent suspension similar to a single oblique arm, while on the other side, the motion of the torsion beam shear center is controlled through motion constraints. This achieves a closer fit to the actual motion of the torsion beam and allows for the simulation of parallel and reverse wheel bounces of the torsion beam suspension within the same motion model. This enables rapid and accurate verification of the dynamic clearances of suspension components and the generation of envelopes for related parts and tires.

[0006] The objective of this invention is achieved through the following technical solution: A modeling method for simulating the motion of a torsion beam suspension includes the following steps: Step S1: Extract the shear center point of the cross section of the torsion beam and other hard points of the torsion beam suspension; Step S2: Divide the torsion beam structure into an independent first rigid body and a second rigid body; Step S3: Establish the first and second drives based on the hard points in step S1. Step S4: Build a first torsion beam suspension model in 3D modeling software, which is equivalent to a single oblique arm independent suspension. Step S5: Build the second torsion beam suspension model in 3D modeling software and control the movement of the shear center; Step S6: Establish motion constraints between the first torsion beam suspension model obtained in step S4 and the second torsion beam suspension model obtained in step S5 to obtain the motion model of the entire torsion beam rear suspension. Step S7: Using the rear suspension motion model established in step S6, set different motion law curves for the first drive and the second drive respectively, so as to realize the dynamic clearance of suspension components and the generation of related parts and tire envelopes under parallel wheel jump and reverse wheel jump conditions.

[0007] Further, step S1 specifically includes the following steps: Step S11: Cut the torsion beam along the longitudinal symmetry plane of the vehicle, extract the crossbeam section of the torsion beam, and solve the first shear center point of the crossbeam in the software. The coordinate point of the first shear center point of the crossbeam should coincide with the longitudinal symmetry plane of the vehicle. Step S12: Obtain the center point of the first wheel, the center point of the first bushing, and the center point of the second wheel and the center point of the second bushing, respectively mirror-symmetrical about the longitudinal symmetry plane of the vehicle, according to the input or from the structural data.

[0008] Further, in step S2, the first rigid body includes the first wheel center point, the first bushing point, and the first shear center point, and the second rigid body includes the second wheel center point, the second bushing point, and the second shear center point; the first shear center point and the second shear center point coincide.

[0009] Further, in step S3, the first drive includes a first lifting surface, which is a horizontal plane passing through the center point of the first wheel; the second drive includes a second lifting surface, which is a horizontal plane passing through the center point of the second wheel. Further, step S4 specifically includes the following steps: Step S41: Connect the first bushing point to the spherical joint of the vehicle body in the 3D modeling software; Step S42: Connect the center point of the first wheel to the surface pair of the first lifting surface in the 3D modeling software.

[0010] Further, in step S5, the second torsion beam suspension model is built in the 3D modeling software, specifically including the following steps: Step S51: In the 3D modeling software, connect the second bushing point to the body rotating joint. The axis of the rotating joint is the line connecting the second bushing point and the first bushing point. Step S52: Connect the center point of the second wheel to the curved surface pair of the second lifting surface in the 3D modeling software.

[0011] Furthermore, in step S6, the motion model of the entire torsion beam rear suspension is established, specifically including the following steps: Step S61: In the 3D modeling software, connect the first shear center in the first torsion beam suspension model with the second shear center spherical joint in the second torsion beam suspension model; Step S62: In the 3D modeling software, connect the first drive and the second drive to the prism pair of the vehicle body respectively. The sliding direction of the prism pair is vertical, so as to realize the vertical movement of the drive wheel.

[0012] Further, step S7 specifically includes: Step S71: Set motion law curves for the first drive and the second drive respectively. When the law curves of the first drive and the second drive are the same, the parallel wheel jump of the suspension can be realized. Then, the dynamic clearance is checked and the envelope is generated. Step S72: To simulate the vehicle's roll motion by simulating the reverse wheel bounce of the suspension, the reverse wheel bounce amount is calculated based on the vehicle's roll angle and wheelbase. Combined with the actual working conditions, different motion law curves are set for the first drive and the second drive respectively to simulate the roll working conditions, and then the verification and envelope generation are performed. For the generation of the envelope of the torsion beam, it is only necessary to take half of the data model, sweep it, and then mirror it.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention provides a modeling method for simulating the motion of a torsion beam suspension. By dividing the torsion beam into two independent rigid bodies, a motion model of an asymmetrical rear suspension is established. On one side, the motion of the torsion beam suspension is equivalent to an independent suspension similar to a single oblique arm. On the other side, the motion of the torsion beam shear center is controlled through motion constraint relationships. By setting the motion law curves of the left and right wheels respectively, various complex working conditions can be freely realized, thereby achieving a closer fit with the actual motion of the torsion beam. 2. The modeling method provided by this invention can be implemented in 3D modeling software without the need to use finite element software to make the torsion beam flexible, and without the need to use multiple software operations. The process is simple and efficient. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart of a modeling method for simulating the motion of a torsion beam suspension according to the present invention; Figure 2a This is one of the schematic diagrams illustrating the process of extracting the shear center of the beam in an embodiment of the present invention; Figure 2b This is a second schematic diagram illustrating the process of extracting the shear center of the beam in an embodiment of the present invention; Figure 3 This is a schematic diagram of the modeling method for a torsion beam suspension according to an embodiment of the present invention. Detailed Implementation

[0016] The present invention will be further described below with reference to embodiments: The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention and not the entire structure.

[0017] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0018] The present invention provides a modeling method for simulating the motion of a torsion beam suspension, such as... Figure 1 As shown, it includes the following steps: Step S1: Extract the shear center point of the cross section of the torsion beam and other hard points of the torsion beam suspension; Step S2: Divide the torsion beam structure into an independent first rigid body and a second rigid body; Step S3: Establish the first and second drives based on the hard points in step S1. Step S4: Build a first torsion beam suspension model in 3D modeling software, which is equivalent to a single oblique arm independent suspension. Step S5: Build the second torsion beam suspension model in 3D modeling software and control the movement of the shear center; Step S6: Establish motion constraints between the first torsion beam suspension model obtained in step S4 and the second torsion beam suspension model obtained in step S5 to obtain the motion model of the entire torsion beam rear suspension. Step S7: Using the rear suspension motion model established in step S6, set different motion law curves for the first drive and the second drive respectively, so as to realize the dynamic clearance of suspension components and the generation of related parts and tire envelopes under parallel wheel jump and reverse wheel jump conditions.

[0019] Specifically, the process of extracting the shear center point of the torsion beam cross section and other hard points of the torsion beam suspension in step S1 is as follows: Step S11: Cut the torsion beam along the longitudinal plane of symmetry of the vehicle, extract the crossbeam section of the torsion beam, and solve for the first shear center point P1 of the crossbeam in the software. The coordinates of the first shear center point of the crossbeam should coincide with the longitudinal plane of symmetry of the vehicle. See [link to software]. Figure 2a , Figure 2b ; Step S12: Obtain the first wheel center point W1 and the first bushing point B1, as well as the second wheel center point W2 and the second bushing point B2, which are mirror-symmetrical about the longitudinal symmetry plane of the vehicle, according to the input or in the structural data. Specifically, in step S2, the torsion beam structure is divided into an independent first rigid body and a second rigid body. The first rigid body includes the first wheel center point W1, the first bushing point B1, and the first shear center point P1; the second rigid body includes the second wheel center point W2, the second bushing point B2, and the second shear center point P2. The first and second shear centers coincide, see... Figure 3 ; Specifically, in step S3, a first drive and a second drive are established based on the hard points in step S1. The first drive includes a first lifting surface, which is a horizontal plane passing through the center point of the first wheel; the second drive includes a second lifting surface, which is a horizontal plane passing through the center point of the second wheel. Specifically, in step S4, a first torsion beam suspension model, equivalent to a single-arm independent suspension, is built in 3D modeling software. The implementation process is as follows: Step S41: Connect the first bushing point B1 to the spherical joint of the vehicle body in the 3D modeling software; Step S42: In the 3D modeling software, connect the center point W1 of the first wheel with the curved surface pair of the first lifting surface. Specifically, in step S5, the second torsion beam suspension model is built in the 3D modeling software. The implementation process is as follows: Step S51: In the 3D modeling software, connect the second bushing point B2 with the body rotating joint. The axis of the rotating joint is the line connecting the second bushing point B2 and the first bushing point B1. Step S52: In the 3D modeling software, connect the center point W2 of the second wheel with the curved surface pair of the second lifting surface. Specifically, in step S6, the motion model of the entire torsion beam rear suspension is established, and the implementation process is as follows: Step S61: In the 3D modeling software, connect the first shear center point P1 in the first torsion beam suspension model with the second shear center P2 in the second torsion beam suspension model using a spherical joint. Step S62: In the 3D modeling software, connect the first drive and the second drive to the prism pair of the vehicle body respectively. The sliding direction of the prism pair is vertical, so as to realize the vertical movement of the drive wheel. Specifically, the method for using the suspension motion model in step S7 is as follows: Step S71: Set motion law curves for the first drive and the second drive respectively. When the law curves of the first drive and the second drive are the same, the parallel wheel jump of the suspension can be realized. Then, the dynamic clearance is checked and the envelope is generated. Step S72: To simulate the vehicle's roll motion by simulating the reverse wheel bounce of the suspension, the reverse wheel bounce amount is calculated based on the vehicle's roll angle and wheelbase. Combined with the actual working conditions, different motion law curves are set for the first drive and the second drive respectively to simulate the roll working conditions, and then the verification and envelope generation are performed. For the generation of the envelope of the torsion beam, it is only necessary to take half of the data model, sweep it, and then mirror it.

[0020] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A modeling method for simulating the motion of a torsion beam suspension, characterized in that, Includes the following steps: Step S1: Extract the shear center point of the cross section of the torsion beam and other hard points of the torsion beam suspension; Step S2: Divide the torsion beam structure into an independent first rigid body and a second rigid body; Step S3: Establish the first and second drives based on the hard points in step S1; Step S4: Build a first torsion beam suspension model in 3D modeling software, which is equivalent to a single oblique arm independent suspension. Step S5: Build the second torsion beam suspension model in 3D modeling software and control the movement of the shear center; Step S6: Establish motion constraints between the first torsion beam suspension model obtained in step S4 and the second torsion beam suspension model obtained in step S5 to obtain the motion model of the entire torsion beam rear suspension. Step S7: Using the rear suspension motion model established in step S6, set different motion law curves for the first drive and the second drive respectively, so as to realize the dynamic clearance of suspension components and the generation of related parts and tire envelopes under parallel wheel jump and reverse wheel jump conditions. Step S4 specifically includes the following steps: Step S41: Connect the first bushing point to the spherical joint of the vehicle body in the 3D modeling software; Step S42: In the 3D modeling software, connect the center point of the first wheel with the surface pair of the first lifting surface point; In step S5, the second torsion beam suspension model is built in the 3D modeling software, specifically including the following steps: Step S51: In the 3D modeling software, connect the second bushing point to the body rotating joint. The axis of the rotating joint is the line connecting the second bushing point and the first bushing point. Step S52: In the 3D modeling software, connect the center point of the second wheel with the curved surface pair of the second lifting surface. In step S6, the motion model of the entire torsion beam rear suspension is established, which specifically includes the following steps: Step S61: In the 3D modeling software, connect the first shear center in the first torsion beam suspension model with the second shear center spherical joint in the second torsion beam suspension model; Step S62: In the 3D modeling software, connect the first drive and the second drive to the prism pair of the vehicle body respectively. The sliding direction of the prism pair is vertical, so as to realize the vertical movement of the drive wheel. The first lifting surface is a horizontal plane passing through the center point of the first wheel, and the second lifting surface is a horizontal plane passing through the center point of the second wheel.

2. The modeling method for simulating the motion of a torsion beam suspension according to claim 1, characterized in that, Step S1 specifically includes the following steps: Step S11: Cut the torsion beam along the longitudinal symmetry plane of the vehicle, extract the crossbeam of the torsion beam, and solve the first shear center point of the crossbeam in the software. The coordinate point of the first shear center point of the crossbeam coincides with the longitudinal symmetry plane of the vehicle. Step S12: Obtain the center point of the first wheel and the first bushing point, as well as the center point of the second wheel and the second bushing point, which are mirror-symmetrical about the longitudinal symmetry plane of the vehicle, according to the input or from the structural data.

3. The modeling method for simulating the motion of a torsion beam suspension according to claim 1, characterized in that: In step S2, the first rigid body includes the center point of the first wheel, the center point of the first bushing, and the center point of the first shear; the second rigid body includes the center point of the second wheel, the center point of the second bushing, and the center point of the second shear; the first shear center point and the second shear center point coincide.

4. The modeling method for simulating the motion of a torsion beam suspension according to claim 1, characterized in that: In step S3, the first drive includes a first lifting surface; the second drive includes a second lifting surface.

5. The modeling method for simulating the motion of a torsion beam suspension according to claim 1, characterized in that, Step S7 is as follows: Step S71: Set motion law curves for the first drive and the second drive respectively. When the law curves of the first drive and the second drive are the same, the parallel wheel jump of the suspension can be realized. Then, the dynamic clearance is checked and the envelope is generated. Step S72: To simulate the vehicle's roll motion by simulating the reverse wheel bounce of the suspension, the reverse wheel bounce amount is calculated based on the vehicle's roll angle and wheelbase. Combined with the actual working conditions, different motion law curves are set for the first drive and the second drive respectively to simulate the roll working conditions, and then the verification and envelope generation are performed. For the generation of the envelope of the torsion beam, it is only necessary to take half of the data model, sweep it, and then mirror it.

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