A method for analyzing a shock absorber tower for improving body roll stability

Abstract

The present application relates to a kind of shock absorber tower analysis method for improving body roll stability, comprising the following steps: S1, establishing body finite element model and chassis kinematics model;S2, constraint first front shock absorber tower top, excitation force is applied at the top of second front shock absorber tower, the stiffness of second front shock absorber tower top is calculated;S3, the stiffness of second front shock absorber tower top is substituted into the two front shock absorber of chassis kinematics model installation point;S4, body roll stability simulation is carried out, and the body roll gradient is calculated;S5, whether the body roll gradient is up to standard is judged, if the body roll gradient is not up to standard, then the structure of two front shock absorber tower top is optimized, and iteration simulation is carried out until the body roll gradient is up to standard.The present application can more truly reflect the body roll performance of car when overbending, can improve the accuracy of analysis, more conducive to the front shock absorber tower structure design in the early stage of car development, can improve analysis verification efficiency, can save time and personnel.

Description

Technical Field

[0001] This invention relates to automotive components, and more specifically to an analysis method for shock absorber towers that improve vehicle roll stability. Background Technology

[0002] As cars become more and more common, consumers have higher and higher requirements for car comfort and safety, which in turn puts forward higher requirements for car handling stability, such as roll stability when driving on mountain roads, curves, ramps, high-speed lane changes or bumpy roads.

[0003] The front shock absorbers of a car are fixed to the front shock absorber towers on both sides of the vehicle body. When the car is driving on a curve or bumpy road, the shock absorber will be subjected to the reaction force from the ground. The reaction force is transmitted to the front shock absorber tower top, causing the tower top to deform. This results in increased body roll when the car is cornering, which reduces the car's driving stability and makes the driver feel unsafe. The structure of the front shock absorber tower top is crucial to body roll stability.

[0004] In traditional chassis dynamics analysis methods, the first approach treats the vehicle body as a rigid component, considering the motion characteristics of chassis system parts, the deformation of elastic elements and bushings, but neglecting the deformation of the body contact points, including the front shock absorber towers. This results in a significant difference between the simulated body roll and the actual vehicle performance. The second approach analyzes the dynamic stiffness of the chassis-body contact points, including the front shock absorber towers, evaluating the 50-100Hz dynamic stiffness of the contact points. However, the actual cornering of a car is close to a quasi-static condition, and the evaluation method for dynamic stiffness is not directly related to the cornering stability of the vehicle. Summary of the Invention

[0005] The purpose of this invention is to propose a shock absorber tower analysis method to improve vehicle body roll stability, which can effectively improve the vehicle's cornering roll stability.

[0006] The shock absorber tower analysis method for improving vehicle roll stability according to the present invention includes the following steps:

[0007] S1. Acquire vehicle body data and establish a finite element model of the vehicle body and a kinematic model of the chassis.

[0008] S2. Using the aforementioned finite element model of the vehicle body, constrain the top of the first front shock absorber tower; apply an excitation force to the top of the second front shock absorber tower, obtain the deformation of the top of the second front shock absorber tower, and calculate the stiffness of the top of the second front shock absorber tower.

[0009] S3. Substitute the stiffness of the second front shock absorber tower top into the mounting points of the two front shock absorbers of the chassis kinematic model to adjust the chassis kinematic model.

[0010] S4. Using the adjusted chassis kinematic model, perform vehicle roll stability simulation and calculate the vehicle roll gradient;

[0011] S5. Determine if the body roll gradient meets the standard. If the body roll gradient does not meet the standard, optimize the structure of the two front shock absorber towers, update the body data, and return to execute S1. Iterate the simulation until the body roll gradient meets the standard.

[0012] Optionally, S2 includes the following steps:

[0013] S21. Fix and constrain the top of the first shock absorber tower;

[0014] S22. Apply an excitation force to the attachment point at the top of the second shock absorber tower. The excitation force has three directions: X, Y, and Z. Measure the static displacement values ​​corresponding to the three directions X, Y, and Z from the finite element model of the vehicle body.

[0015] S23, divide the excitation force by the static displacement value to obtain the stiffness of the second shock absorber tower top in the XYZ directions.

[0016] Optionally, the optimized structure of the two front shock absorber tower tops includes setting a reinforcing structure on the two front shock absorber tower tops.

[0017] Optionally, the optimized structure of the two front shock absorber tower tops includes providing a stabilizing rod, the two ends of which are respectively connected to the two front shock absorber tower tops, and the stabilizing rod is integrally formed with the two front shock absorber tower tops.

[0018] Optionally, the optimized structure of the two front shock absorber tower tops includes providing detachable stabilizer bars, the two ends of which are detachably connected to the two front shock absorber tower tops respectively.

[0019] Optionally, optimizing the structure of the two front shock absorber tower tops includes adjusting the shape and / or size and / or material of the detachable stabilizer bar.

[0020] Optionally, the detachable stabilizer bar includes a reinforcing bar, a left mounting base, and a right mounting base, wherein the left mounting base and the right mounting base are symmetrical to each other; the left mounting base and the right mounting base are respectively used to connect to the top of the two front shock absorbers of the vehicle; the left mounting base is provided with a strip-shaped hole extending in the left-right direction, and the left end of the reinforcing bar is fixedly connected to the left mounting base through a locking structure that cooperates with the strip-shaped hole. When the locking structure is unlocked, the locking structure can slide along the length direction of the strip-shaped hole.

[0021] This invention offers at least the following advantages: By flexibly simulating the front shock absorber towers during chassis dynamics simulation, and accumulating the vehicle's body deformation and the chassis system's motion and deformation during cornering, the lateral roll performance of the vehicle during cornering can be more realistically reflected. This improves the accuracy of the analysis, facilitates the early-stage design of the front shock absorber tower structure in vehicle development, enhances analysis and verification efficiency, saves time and personnel, and effectively shortens the development cycle. It also provides a scheme to optimize the structure of the two front shock absorber tower tops, which can significantly improve the vehicle's roll stability. Attached Figure Description

[0022] Figure 1 This is a flowchart of the shock absorber tower analysis method for improving vehicle roll stability as described in the specific implementation.

[0023] Figure 2 This is a schematic diagram of the detachable stabilizer bar described in the specific implementation embodiment;

[0024] Figure 3 This is a schematic diagram of the reinforcing rod described in a specific embodiment;

[0025] Figure 4 This is a schematic diagram of the left mounting base as described in a specific embodiment. Detailed Implementation

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] like Figure 1 The shock absorber tower analysis method for improving vehicle roll stability, as shown, includes the following steps:

[0028] S1. Obtain vehicle body data, establish a finite element model of the vehicle body and a kinematic model of the chassis. The thickness and material parameters of each part of the finite element model of the vehicle body are the same as the thickness and material parameters of the corresponding actual structure on the real vehicle. Perform mesh quality checks on the finite element model of the vehicle body to verify the accuracy of the model.

[0029] S2. Using the aforementioned finite element model of the vehicle body, constrain the top of the first front shock absorber tower; apply an excitation force to the top of the second front shock absorber tower, obtain the deformation of the top of the second front shock absorber tower, and calculate the stiffness of the top of the second front shock absorber tower.

[0030] Specifically, S2 includes the following steps:

[0031] S21. Using the aforementioned vehicle body finite element model, a fixed constraint is applied to the top of the first shock absorber tower, and this constraint is used as the boundary condition of the vehicle body finite element model.

[0032] S22. Apply a fixed excitation force to the attachment point at the top of the second shock absorber tower. The direction of the fixed excitation force includes three directions: X, Y, and Z. Measure the static displacement values ​​corresponding to the three directions X, Y, and Z from the finite element model of the vehicle body.

[0033] S23, using the static displacement value, the stiffness of the top of the second shock absorber tower in the XYZ directions is calculated.

[0034] S3. Substitute the stiffness of the second front shock absorber tower top into the mounting points of the two front shock absorbers of the chassis kinematic model to adjust the chassis kinematic model.

[0035] S4. Using the adjusted chassis kinematic model, perform vehicle roll stability simulation and calculate the vehicle roll gradient. Specifically, the vehicle roll stability simulation is a steady-state turning vehicle roll stability simulation, which involves importing the chassis kinematic model into Adams software, setting a circle of fixed radius in the virtual test track, and allowing the vehicle to drive around the circumference with an acceleration of 0.05g until it loses control. Measure the roll angle of the vehicle throughout the process. The ratio of the maximum roll angle before loss of control to the maximum lateral acceleration is the vehicle roll gradient.

[0036] S5. Compare the body roll gradient calculated in S4 with the target value to determine whether the body roll gradient meets the standard. If the body roll gradient does not meet the standard, optimize the structure of the two front shock absorber tower tops, update the body data, and return to execute S1. Iterate the simulation until the body roll gradient meets the standard.

[0037] In some embodiments, optimizing the structure of the two front shock absorber towers includes providing a reinforcing structure on the two front shock absorber towers. Specifically, the reinforcing structure may be a reinforcing rib, or it may be a reinforcing rib plate connected between the front shock absorber towers and the vehicle body.

[0038] In some embodiments, optimizing the structure of the two front shock absorber towers includes providing a stabilizer bar, with both ends of the stabilizer bar connected to the two front shock absorber towers respectively, and the stabilizer bar is integrally formed with the two front shock absorber towers. The stabilizer bar can effectively improve vehicle roll stability.

[0039] In some embodiments, optimizing the structure of the two front shock absorber tower tops includes providing detachable stabilizer bars, the two ends of which are detachably connected to the two front shock absorber tower tops respectively.

[0040] In some embodiments, optimizing the structure of the two front shock absorber tower tops includes adjusting the shape and / or size and / or material of the detachable stabilizer bar.

[0041] In practical implementation, during iterative simulation, a reinforcing structure can be initially installed on the tops of the two front shock absorber towers. If this fails to achieve the desired body roll gradient, a detachable stabilizer bar can be installed in the next iteration. The shape, size, and / or material of the detachable stabilizer bar can be adjusted in subsequent iterations. If installing a detachable stabilizer bar between the two front shock absorber towers fails to achieve the desired body roll gradient, a stabilizer bar section can be installed between the two front shock absorber towers in the next iteration. The shape, size, and / or material of the stabilizer bar section can be adjusted in subsequent iterations until the desired body roll gradient is achieved. Typically, achieving the desired body roll gradient is achieved after installing and adjusting the design parameters of the detachable stabilizer bar.

[0042] In some embodiments, such as Figures 2 to 4 As shown, the detachable stabilizer bar includes a reinforcing bar, a left mounting base 3, and a right mounting base 4. The left mounting base 3 and the right mounting base 4 are symmetrical structures. The left mounting base 3 and the right mounting base 4 are respectively used to connect to the tops of the two front shock absorbers of the vehicle. The left mounting base 3 is provided with a strip-shaped hole 35 extending in the left-right direction. The left end of the reinforcing bar is fixedly connected to the left mounting base 3 through a locking structure that cooperates with the strip-shaped hole 35. When the locking structure is unlocked, the locking structure can slide along the length direction of the strip-shaped hole 35.

[0043] The above-described solution connects the left and right front shock absorber towers using a detachable stabilizer bar, effectively increasing their stiffness. This reduces the deformation caused by ground excitation when the vehicle turns or travels on bumpy roads, thus decreasing body roll and improving vehicle stability. By providing slotted holes 35 on the left and right mounting brackets 3 and connecting them to a reinforcing bar, the distance between the brackets can be adjusted. This allows the detachable stabilizer bar to be used on vehicles of different sizes and track widths, offering high versatility and reducing production costs. The symmetrical arrangement of the left and right mounting brackets 3 and 4, making them interchangeable, further reduces production costs and ensures the balance of the detachable stabilizer bar.

[0044] In some embodiments, the reinforcing bar includes a flat reinforcing bar body 1 in the vertical direction. The reinforcing bar body 1 is arched. Using the above-mentioned reinforcing bar body 1 can effectively enhance the overall rigidity of the vehicle body and absorb the excitation transmitted from the shock absorber. The reinforcing bar body 1 includes a left segment 12, a middle segment 11, and a right segment 13 connected sequentially from left to right. The left segment 12 slopes downward from right to left, and the right segment 13 slopes downward from left to right.

[0045] In some embodiments, the reinforcing rod further includes two connecting sleeves 2, the central axes of which extend in the front-rear direction. The two connecting sleeves 2 are fixedly connected to the left and right ends of the reinforcing rod body 1 by welding, and the two connecting sleeves 2 are used to connect the left mounting base 3 and the right mounting base 4, respectively.

[0046] In some embodiments, hollow reinforcing ribs 14 are provided on both the front and rear edges of the reinforcing rod body 1. Providing hollow reinforcing ribs 14 can improve the rigidity of the reinforcing rod body 1, which is beneficial for reducing the weight of the reinforcing rod body 1 and thus contributing to the lightweighting of the vehicle.

[0047] In some embodiments, the locking structure includes a bolt and a nut. The bolt passes through the slot 35 and is threadedly connected to the left end of the reinforcing rod with the nut. Loosening the nut allows the bolt to slide along the length of the slot 35, while tightening the nut secures the left mounting base 3 and the left end of the reinforcing rod together. This design offers advantages such as easy adjustment and a simple structure.

[0048] In some embodiments, the left mounting base 3 is provided with two upright plates 34, forming a reinforcing rod connecting groove between the two upright plates 34, and each upright plate 34 is provided with a strip hole 35. The two upright plates 34 ensure the stability of the connection between the left mounting base 3 and the reinforcing rod. As a preferred embodiment, a bolt passes sequentially through the strip hole 35 on one upright plate 34, the connecting sleeve 2 at the left end of the reinforcing rod, and the strip hole 35 on the other upright plate 34 before being threaded onto a nut. Tightening the nut secures the two upright plates 34 and the connecting sleeve 2 at the left end of the reinforcing rod together.

[0049] In some embodiments, the left mounting base 3 is provided with three mounting holes 32 for connecting to the top of the left front shock absorber of the vehicle. The three mounting holes 32 correspond to the three screws on the upper mounting base of the left front shock absorber, so that the left mounting base 3 can be installed using the three screws on the upper mounting base of the left front shock absorber. The installation is simple and convenient, without the need for additional mounting holes and fasteners.

[0050] In some embodiments, the left mounting base 3 is provided with a clearance hole 33 for avoiding the upper mounting base of the left front shock absorber. The clearance hole 33 is used to avoid the upper mounting base of the left front shock absorber, making the installation of the left front shock absorber more convenient and quick.

[0051] In one embodiment, a base plate 31 is stacked and fixedly connected to the top of the left front shock absorber on the left mounting base 3. Three mounting holes 32 and clearance holes 33 are all provided on the base plate 31. In a specific implementation, two upright plates 34 are welded to the upper side of the base plate 31. In order to ensure structural strength, an inclined plate 36 is also connected between the upright plates 34 and the base plate 31.

[0052] In some embodiments, the reinforcing rod, left mounting bracket 3, and right mounting bracket 4 are all made of aluminum alloy. This further reduces weight while maintaining component strength, contributing to the lightweighting of the vehicle.

[0053] The shock absorber tower analysis method for improving vehicle roll stability proposed in this application has the following beneficial effects:

[0054] The shock absorber tower analysis method for improving vehicle roll stability proposed in this application considers the deformation of the shock absorber tower top itself due to road surface excitation. By importing the shock absorber tower stiffness into the chassis kinematic model and performing flexible processing, roll stability simulation analysis is conducted. This method incorporates the deformation of the vehicle body and the motion and deformation of the chassis system when the vehicle is cornering, which can more realistically reflect the roll performance of the vehicle when cornering. This improves the accuracy and precision of roll stability analysis, and is more conducive to the design of the front shock absorber tower structure in the early stage of vehicle development. It improves the efficiency of analysis and verification, saves time and personnel, and effectively shortens the development cycle. Furthermore, this analysis method can be further extended to all chassis and body attachment points in the chassis kinematic model.

[0055] This application presents an optimized solution using a stabilizer bar or a detachable stabilizer bar. By connecting the shock absorber towers on both sides, the rigidity of the shock absorber towers is improved, which can effectively reduce the body roll, enhance the body roll stability of the vehicle when cornering or driving on bumpy roads, and increase the driver's confidence.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics incorporated in that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

Claims

1. A shock absorber tower analysis method for improving vehicle body roll stability, characterized in that, Includes the following steps: S1. Acquire vehicle body data and establish a finite element model of the vehicle body and a kinematic model of the chassis. S2. Using the aforementioned finite element model of the vehicle body, constrain the top of the first front shock absorber tower; An excitation force is applied to the top of the second front shock absorber tower, the deformation of the top of the second front shock absorber tower is obtained, and the stiffness of the top of the second front shock absorber tower is calculated. S3. Substitute the stiffness of the second front shock absorber tower top into the mounting points of the two front shock absorbers of the chassis kinematic model to adjust the chassis kinematic model. S4. Using the adjusted chassis kinematic model, perform vehicle roll stability simulation and calculate the vehicle roll gradient; S5. Determine if the body roll gradient meets the standard. If the body roll gradient does not meet the standard, optimize the structure of the two front shock absorber towers, update the body data, and return to execute S1. Iterate the simulation until the body roll gradient meets the standard.

2. The shock absorber tower analysis method for improving vehicle body roll stability according to claim 1, characterized in that, S2 includes the following steps: S21. Fix and constrain the top of the first shock absorber tower; S22. Apply an excitation force to the attachment point at the top of the second shock absorber tower. The excitation force has three directions: X, Y, and Z. Measure the static displacement values ​​corresponding to the three directions X, Y, and Z from the finite element model of the vehicle body. S23, divide the excitation force by the static displacement value to obtain the stiffness of the second shock absorber tower top in the XYZ directions.

3. The shock absorber tower analysis method for improving vehicle body roll stability according to claim 1, characterized in that, The optimized structure of the two front shock absorber tower tops includes setting a reinforcing structure on the two front shock absorber tower tops.

4. The shock absorber tower analysis method for improving vehicle body roll stability according to claim 1, characterized in that, The optimized structure of the two front shock absorber tower tops includes the provision of a stabilizing rod, the two ends of which are respectively connected to the two front shock absorber tower tops, and the stabilizing rod is integrally formed with the two front shock absorber tower tops.

5. The shock absorber tower analysis method for improving vehicle body roll stability according to claim 1, characterized in that, The optimized structure of the two front shock absorber tower tops includes the installation of detachable stabilizer bars, the two ends of which are detachably connected to the two front shock absorber tower tops respectively.

6. The shock absorber tower analysis method for improving vehicle body roll stability according to claim 5, characterized in that, The optimization of the structure of the two front shock absorber tower tops includes adjusting the shape and / or size and / or material of the detachable stabilizer bar.

7. The shock absorber tower analysis method for improving vehicle body roll stability according to claim 5, characterized in that, The detachable stabilizer bar includes a reinforcing bar, a left mounting base, and a right mounting base, the left and right mounting bases being symmetrical structures. The left and right mounting bases are respectively used to connect to the tops of the two front shock absorbers of the vehicle. The left mounting base is provided with a strip-shaped hole extending in the left-right direction. The left end of the reinforcing bar is fixedly connected to the left mounting base through a locking structure that mates with the strip-shaped hole. When the locking structure is unlocked, the locking structure can slide along the length direction of the strip-shaped hole.

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