A method for simulating the pull-out force of a damper for a wrap-around front steering knuckle

Abstract

The present application relates to the field of automobile simulation technology, and provides a pull-out force simulation analysis method for a shock absorber of a ring-type front steering knuckle, comprising the following steps: S1, simulating to obtain the minimum pull-out force of the shock absorber based on the maximum gap between the shock absorber and the ring-type steering knuckle and the minimum tightening force of the side bolts of the ring-type steering knuckle; S2, obtaining the maximum stress value of the end of the shock absorber connected with the ring-type steering knuckle in the pull-out direction; S3, detecting whether the maximum stress value of the shock absorber in the pull-out direction is less than the minimum pull-out force of the shock absorber, if the detection result is yes, it is determined that the shock absorber does not exist the pull-out risk, if the detection result is no, it is determined that the shock absorber exists the pull-out risk. The present application provides a kind of CAE simulation method for the design and development of shock absorber pull-out force, not only avoids the risk of shock absorber being pulled out in later road test and after-sales, but also shortens the development cycle, reduces the development cost, and guarantees the product quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile simulation technology, and provides a simulation analysis method for the pull-out force of a shock absorber of a ring-type front steering knuckle. BACKGROUND

[0002] At present, the front suspension of the automobile industry mostly adopts the MacPherson suspension, and the lower end of the front slide column is connected with the front steering knuckle through a U-shaped support (also called AB support in the industry) and is fastened by a fastener. This connection mode causes the parameters of the four wheels to change after the vehicle has traveled a certain distance, which eventually leads to deviation and causes tire wear. In order to avoid this problem, the front steering knuckle and the front shock absorber currently adopt a ring structure to avoid the above-mentioned problems. During the development process of the product, the pull-out force of the shock absorber needs to be repeatedly verified, which requires additional manpower and resources, prolongs the development cycle, increases the development cost, and affects the product launch. SUMMARY

[0003] The present application provides a simulation analysis method for the pull-out force of a shock absorber of a ring-type front steering knuckle, aiming to improve the above-mentioned problems.

[0004] The present application is implemented as follows: a simulation analysis method for the pull-out force of a shock absorber of a ring-type front steering knuckle, which specifically comprises the following steps:

[0005] S1. Simulate and obtain the minimum pull-out force of the shock absorber based on the maximum gap between the shock absorber and the ring-type steering knuckle and the minimum fastening force of the bolts on the side surface of the ring-type steering knuckle;

[0006] S2. Obtain the maximum force value in the pull-out direction of the end portion of the shock absorber connected with the ring-type steering knuckle;

[0007] S3. Detect whether the maximum force value in the pull-out direction of the shock absorber is less than the minimum pull-out force of the shock absorber. If the detection result is yes, it is determined that the shock absorber does not have the risk of being pulled out, and if the detection result is no, it is determined that the shock absorber has the risk of being pulled out.

[0008] Further, the minimum pull-out force of the shock absorber is simulated and obtained based on the Abaqus software.

[0009] Further, the step S1 specifically comprises the following steps:

[0010] S11. Retrieve the three-dimensional data of the ring-type steering knuckle and the shock absorber, and perform finite element mesh processing;

[0011] S12. Define the material properties of the ring-type steering knuckle and the shock absorber in the CAE model;

[0012] Further, the material properties of the ring around the steering knuckle include the Young's modulus, Poisson's ratio and density of the material, further, the material properties of the damper include the elastic modulus, Poisson's ratio and density of the material.

[0013] S13, rigidly connecting the tire hub and the bearing mounting hole inner surface of the ring around the steering knuckle in the abaqus model;

[0014] S14, setting the radial gap between the ring around the steering knuckle and the damper to the maximum gap value in the abaqus model;

[0015] S15, setting the friction coefficient between the damper and the ring around the steering knuckle in the abaqus model;

[0016] S16, taking the tightening torque of the ring around the side bolt as the minimum value;

[0017] S17, starting to apply force to the damper along the axial direction of the damper pulling-out direction in the abaqus model, stopping after the damper moves along the axial direction of the pulling-out direction, at this time, the force applied to the damper is the minimum pulling-out force of the damper.

[0018] Further, the ring around the steering knuckle has an upper limit value of the diameter, and the outer diameter of the damper has a lower limit value, and the difference between the two is the radial gap between the ring around the steering knuckle and the damper set to the maximum gap value.

[0019] Further, the maximum stress value of the damper end connected with the ring around the steering knuckle in the pulling-out direction is obtained based on the adams software.

[0020] Further, the step S2 comprises the following steps:

[0021] S21, analyzing the axial stress of the damper end in the damper pulling-out direction under various working conditions based on the adams software;

[0022] S22, the maximum stress is the maximum stress of the damper end connected with the ring around the steering knuckle in the pulling-out direction.

[0023] Further, the working conditions include:

[0024] The vertical jump working condition, the braking working condition, the starting working condition, the reverse working condition, the right turning working condition, the left turning working condition, the forward passing bump working condition, the reverse passing bump working condition, the vertical impact working condition, the longitudinal impact working condition, the left wheel lateral impact working condition and the right wheel lateral impact working condition.

[0025] The present application provides a kind of accurate CAE simulation method for damper pulling-out force design and development, not only avoids the risk of damper being pulled out in later road test and after-sales, simultaneously shortens development cycle, reduces development cost, guarantees product quality. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A shock absorber and a surrounding steering knuckle connecting structure schematic view provided for an embodiment of the present application;

[0027] Figure 2 A shock absorber and a surrounding steering knuckle connecting structure schematic view provided for an embodiment of the present application;

[0028] Figure 3 A shock absorber and a surrounding steering knuckle connecting structure schematic view provided for an embodiment of the present application; DETAILED DESCRIPTION

[0029] The specific embodiments of the present application are further described in detail below with reference to the drawings.

[0030] The present application provides a precise CAE simulation method for the pull-out force of a shock absorber, which avoids late road tests and reduces the risk of post-sale shock absorbers being pulled out, while improving the stability of four-wheel parameters.

[0031] Figure 2 A shock absorber and a surrounding steering knuckle connecting structure schematic view provided for an embodiment of the present application;

[0032] S1, based on the maximum gap between the shock absorber and the surrounding steering knuckle and the minimum tightening force of the side bolts of the surrounding steering knuckle, the minimum pull-out force of the shock absorber is simulated and obtained;

[0033] The end of the shock absorber is inserted into the surrounding of the surrounding steering knuckle, the side of the surrounding is provided with bolts, and the shock absorber inserted into the steering knuckle is fastened through the bolts, and the connection of the shock absorber and the surrounding front steering knuckle is shown in Figure 1 .

[0034] In the embodiment of the present application, the minimum pull-out force of the shock absorber is simulated based on the abaqus software, and the simulation process is specifically as follows:

[0035] S11, three-dimensional data of the surrounding steering knuckle and the shock absorber are called and finite element mesh processing is performed;

[0036] S12, the material properties of the surrounding steering knuckle and the shock absorber are defined in the CAE model, the Young's modulus, Poisson's ratio and density of the material are mainly defined for the surrounding steering knuckle, and the elastic modulus, Poisson's ratio and density of the material are defined for the shock absorber.

[0037] S13, the tire hub and the inner surface of the bearing mounting hole of the surrounding steering knuckle are rigidly connected in the abaqus model, and the hub is constrained in 6 directions.

[0038] S14, the radial gap between the surrounding steering knuckle and the shock absorber is set to the maximum gap value in the abaqus model.

[0039] In the embodiment of the present application, the upper limit value is taken for the embracing diameter of the knuckle, the lower limit value is taken for the outer diameter of the shock absorber, and the difference between the two is the radial clearance between the embracing knuckle and the shock absorber, which is set to the maximum clearance value.

[0040] S15, according to the roughness of the inner surface of the embracing knuckle and the outer surface of the shock absorber, the friction coefficient between the shock absorber and the embracing knuckle in the abaqus model is set;

[0041] S16, the tightening torque of the embracing side bolt is taken as the minimum value;

[0042] S17, in the abaqus model, the force is applied to the shock absorber along the axial direction of the shock absorber pulling-out direction, and the shock absorber is stopped after moving along the axial direction of the pulling-out direction, at this time, the force applied to the shock absorber is the minimum pulling-out force of the shock absorber.

[0043] The maximum clearance and the minimum tightening torque are taken for simulation analysis, which is according to the limit condition to simulate and analyze the pulling-out force of the shock absorber, and the purpose is to avoid the shock absorber being pulled out after mass production as much as possible.

[0044] S2, the maximum force value of the end of the shock absorber connected with the embracing knuckle in the pulling-out direction is obtained;

[0045] In the embodiment of the present application, the maximum force value of the end of the shock absorber in the pulling-out direction under various working conditions is obtained as follows:

[0046] S21, based on the adams software, the axial force of the end of the shock absorber in the pulling-out direction of the shock absorber under various working conditions is analyzed;

[0047] In the embodiment of the present application, the above working conditions include: vertical jump working condition, braking working condition, starting working condition, reversing working condition, right turning working condition, left turning working condition, forward driving over a bump working condition, reversing over a bump working condition, vertical impact working condition, longitudinal impact working condition, left wheel lateral impact working condition and right wheel lateral impact working condition.

[0048] S22, the maximum force is the maximum force of the end of the shock absorber connected with the embracing knuckle in the pulling-out direction.

[0049] S3, whether the maximum force value of the shock absorber in the pulling-out direction is less than the minimum pulling-out force of the shock absorber is detected, if the detection result is yes, it is determined that the shock absorber does not exist pulling-out risk, if the detection result is no, it is determined that the shock absorber exists pulling-out risk.

[0050] The following is a specific embodiment provided by the present application, which is as follows:

[0051] The radial clearance between the embracing knuckle and the shock absorber is set as: the embracing diameter of the knuckle is 55.17±0.005 mm, the outer diameter of the shock absorber is 55(+0.17 / -0.06) mm, and the simulation is carried out under the most stringent condition, that is, the embracing diameter of the knuckle is taken as the upper limit 55.17+0.005 mm, and the radial clearance between the embracing knuckle and the shock absorber is set as 0.235 mm in the abaqus model;

[0052] The friction coefficient between the shock absorber and the embracing knuckle is set as 0.15 in the abaqus model;

[0053] The axial force of the side bolt of the embracing knuckle is converted into: T=uFd, wherein the side bolt tightening torque is 120±10 N·M, the friction coefficient u of the fastener (the friction coefficient u of the standard part of Chery Company is 0.09-0.15) is defined as 0.2 considering the friction coefficient of the standard part of other main manufacturers, the friction coefficient u is taken as 0.2, the tightening torque T is taken as the lower limit 110 N·M, d represents the diameter of the outer thread of the bolt, and the axial tightening force F is F=T / ud, and then the tightening force is calculated as 45.8 kN, that is, the cylinder of the knuckle is deformed to hold the shock absorber when the side bolt is tightened to 110 N·M, and the pulling-out force required by the held shock absorber is calculated based on the following method;

[0054] The force is applied along the axial direction of the shock absorber to carry out simulation until the simulation model moves along the axis, and then the simulation analysis result is stopped. Figure 3 It can be seen that the minimum pulling-out force of the cast aluminum front knuckle is 36.68 kN.

[0055] The Z-direction stress of the front shock absorber under 12 working conditions is analyzed by using the adams software.

[0056]

[0057] It is found through the comparison of the Z-direction stress of the lower mounting point of the front shock absorber that the maximum stress of the lower end of the front shock absorber under the vertical impact working condition is 31061.9 N, about 3.11 kN. The pulling-out force of the shock absorber is 36.68 kN which is greater than the load decomposition 3.11 kN according to the most stringent simulation, so the shock absorber does not exist the risk of being pulled out.

[0058] The present application is described by way of example, and it is obvious that the specific implementation of the present application is not limited to the above method. Various non-essential improvements or direct application of the concept and technical solution of the present application to other occasions are within the protection scope of the present application.

Claims

1. A method for analyzing a pull-out force of a damper for a wrap-around front steering knuckle, characterized by, The method specifically comprises the following steps: S1, based on the maximum gap between the shock absorber and the knuckle and the minimum tightening force of the side bolt of the knuckle, the minimum pull-out force of the shock absorber is simulated and obtained; S2, the maximum force value of the end of the shock absorber connected with the knuckle in the pull-out direction is obtained; S3, whether the maximum force value of the shock absorber in the pull-out direction is less than the minimum pull-out force of the shock absorber is detected, if the detection result is yes, it is determined that the shock absorber does not exist pull-out risk, if the detection result is no, it is determined that the shock absorber exists pull-out risk; The step S1 specifically comprises the following steps: S11, the three-dimensional data of the knuckle and the shock absorber is called and finite element mesh processing is performed; S12, the material properties of the knuckle and the shock absorber are defined in the CAE model; S13, the hub and the inner surface of the bearing mounting hole of the knuckle are rigidly connected in the abaqus model; S14, the radial gap between the knuckle and the shock absorber is set to the maximum gap value in the abaqus model; S15, the friction coefficient between the shock absorber and the knuckle is set in the abaqus model; S16, the tightening torque of the side bolt is taken as the minimum value; S17, in the abaqus model, force is applied to the shock absorber along the axial direction of the pull-out direction of the shock absorber, and the shock absorber is stopped after moving along the axial direction of the pull-out direction, at this time, the force applied to the shock absorber is the minimum pull-out force of the shock absorber.

2. The method of claim 1, wherein the method is for a pull-out force simulation analysis of a shock absorber for a wrap-around front steering knuckle. The minimum pull-out force of the shock absorber is simulated and obtained based on the abaqus software.

3. The method of claim 1, wherein the method is for a pull-out force simulation analysis of a shock absorber for a wrap-around front steering knuckle. The upper limit value of the diameter of the knuckle and the lower limit value of the outer diameter of the shock absorber are taken, and the difference between the two is the maximum gap value of the radial gap between the knuckle and the shock absorber.

4. The method of claim 1, wherein the method is for a pull-out force simulation analysis of a shock absorber for a wrap-around front steering knuckle. The maximum force value of the end of the shock absorber connected with the knuckle in the pull-out direction is obtained based on the adams software.

5. The method of claim 4, wherein the method is for a pull-out force simulation analysis of a shock absorber for a wrap-around front steering knuckle. The step S2 comprises the following steps: S21, based on the adams software, the axial force of the end of the shock absorber in the pull-out direction of the shock absorber under multiple working conditions is analyzed; S22, the maximum force is the maximum force of the end of the shock absorber connected with the knuckle in the pull-out direction.

6. The method of claim 5, wherein the method is for a pull-out force simulation analysis of a shock absorber for a wrap-around front steering knuckle. The working conditions include: Vertical jump working condition, braking working condition, starting working condition, reversing working condition, right turning working condition, left turning working condition, forward driving over a bump working condition, reversing over a bump working condition, vertical impact working condition, longitudinal impact working condition, left wheel lateral impact working condition and right wheel lateral impact working condition.

7. The method of claim 1, wherein the method is for a pull-out force simulation analysis of a shock absorber for a wrap-around front steering knuckle. The material properties of the knuckle include the Young's modulus, Poisson's ratio and density of the material.

8. The method of claim 1, wherein the method is for a pull-out force simulation analysis of a shock absorber for a wrap-around front steering knuckle. The material properties of the shock absorber include the elastic modulus, Poisson's ratio and density of the material.

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