RU2518425C1 - Method for determination of technical actions parameters during vehicle wheels mounting - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: method for determination of technical actions parameters during vehicle wheels mounting consists in the following: before adjustment, specified numeric values of wheel setting parameters are entered in simulation model describing relationships of wheel setting parameters change due to change of geometrical parameters of vehicle adjustment elements. numeric values of wheel mounting technical actions parameters are calculated according to solution of proposed equation systems.

EFFECT: lower labour consumption during vehicle chassis maintenance.

3 dwg, 7 tbl

Description

The invention relates to transport engineering and can be used for maintenance work on the undercarriage of a car, namely, to regulate camber and toe-in or longitudinal tilt of the axis of rotation of the wheel.

The technological process of ensuring the installation of automobile wheels consists of the steps of determining the installation parameters of the wheels and bringing the measured values of these parameters to standard values. However, if for the implementation of the first stage there are a sufficient number of methods that differ in the accuracy of the measurement results and the complexity of the work, then the second stage is not given enough attention.

The greatest difficulty is the joint adjustment of the camber and the longitudinal angle of inclination of the axis of rotation of the wheel in suspensions with fork arms of an asymmetric configuration. Due to the complex relationship of the parameters under consideration and insufficient information support, the adjustment process itself may have an iterative nature. During each iteration, a cycle is carried out consisting in calculating the deviations of the adjustable parameters, disassembling the adjusting device, removing or installing adjusting elements (washers, brackets, etc.), assembling the adjusting device with the mandatory performance of fixing operations in accordance with the requirements of the technical conditions and measurement the achieved values of the camber and the longitudinal angle of inclination of the axles of rotation of the wheels. In this case, the complexity of the adjustment operations can far exceed the complexity of determining the parameters of the installation of the wheels.

Known methods for determining, adjusting and controlling the adjustment of wheel settings [Patent RU No. 2314492 C1, IPC G018 11/26, publ. January 10, 2008; Patent RU No. 2368883 C2, IPC G01M 17/00, G01B 11/26, publ. 09/27/2009; Patent RU No. 2083413 C1, IPC B62D 17/00, publ. 04/20/2002], to determine the convergence and camber. The known method [Patent RU No. 2073226 C1, IPC G01M 17/06, publ. October 20, 2002], which makes it possible to measure the camber and the longitudinal angle of inclination of the axis of rotation of the wheel.

However, these methods do not affect the technology of achieving a given change in camber and longitudinal angle of inclination of the axis of rotation of the wheel and do not contain information about the required technical effects on the elements of the adjusting device that determine the set values of the changes in the considered parameters of the wheels.

There is a method of selecting the parameters of technical effects when adjusting the camber and the longitudinal angle of inclination of the axis of rotation of the wheel for car suspensions with asymmetric fork arms and insertion washers using tables [Pyatkov KB Repair manual VA3-2121, 21212, 21219. Operation, maintenance / К.Б. Pyatkov, A.P. Ignatov, K.V. Novokshonov. - M .: Livre, 1995. - 149 pp.], Which consists in using experimental data of the relationship between the change in the number of washers under the front and rear bolts of the forked suspension arm and the change in camber and longitudinal tilt of the axis of rotation of the automobile wheel (see Fig. 1, 2, 3) according to the plan of a full two-factor experiment with a central point (Table 1).

This method can legitimately be used only with the thickness of one shim and the thickness of the shims at which measurements were made. Outside of this range, due to the complexity of the relationship between the considered parameters, the ratio between the change in the parameters of technical impacts and the change in camber and longitudinal angle of the axis of rotation of the wheel will be different. Therefore, beyond the limits of the above dependences (Table 1), it is necessary to use the “trial and error” method, which is associated with an indefinite number of iterations.

Table 1 Changing the camber angle and the longitudinal inclination of the axis of rotation when changing the number of washers in the packages of the forked arm of the car VA3-21213 Number of washers added to or removed from the bag Collapse The longitudinal angle of inclination of the axis of rotation of the wheel Front bolt Rear bolt +1 +1 + (8'42``) 0 -one -one - (8'42``) 0 +1 0 + (7'30``) + (20'24``) -one 0 - (7'30``) - (20'24``) 0 +1 + (15'18``) - (25'18``) 0 -one - (15'18 '') + (25'18``) -one +1 + (27'30``) - (43'18 '') +1 -one - (21'36``) + (40 ')

The disadvantages of this method are related to the need to take into account the restrictions: the minimum and maximum permissible thickness of the adjusting gaskets (washers, brackets) and the difference in their thickness under the front and rear bolts of the forked suspension arm, the permissible difference in the values of the installation parameters of the wheels for the left and right wheels of the car. The method is characterized by a high complexity of work.

A known method for determining the numerical values of the parameters of the technical effects [Technical operation of cars. Textbook for high schools / E.S. Kuznetsov, A.P. Boldin, V.M. Vlasov et al. - M .: Nauka, 2001. - 535 p.], In which, on the basis of experiments, the relationships between changes in the camber and the longitudinal angle of inclination of the axis of rotation of the wheels of the car from changes in the thickness of the adjusting brackets (gaskets) under the front and rear forks the suspension arm for the wheel of the front axle of the car.

Based on these data, a nomogram is compiled (Fig. 4), and then, when adjusting the parameters, the actual deviations of the camber and the longitudinal tilt of the axis of rotation of the wheels from the standards are calculated and the parameters of the necessary technical influences are determined from the nomogram. The method involves selecting the number of gaskets, having previously determined the necessary changes in the adjustment parameters, first for one wheel of the axle and then for another wheel of the front axle of the car. The disadvantages of this method are that the nomogram takes into account only linear dependencies between the wheel mounting parameters and the change in the parameters of the adjusting devices, as a result of which the method is unsuitable for the asymmetric configuration of the control levers, for which the dependencies between the considered parameters are more complex. Certain difficulties are associated with the need to take into account the limitations: the minimum and maximum permissible thickness of the adjusting washers, the permissible difference in their thickness under the front and rear bolts of the fork lever, the permissible difference in the installation parameters of the wheels between the left and right wheels of one axis of the car, which entails an increase in the complexity of adjusting operations.

The closest technical solution to the claimed one is a method of obtaining information about the necessary adjusting influences when adjusting the wheel mounting parameters on cars with fork suspension arms [http: // www.hunter.com.ru / upload / pdf / manual / 4813 TE - 35 pdf. - S.56-58, 72-77], based on tracking changes in camber and longitudinal tilt of the axis of rotation of the wheel from changing the values of the adjusting elements on the monitor screen of specialized computer stands. The method allows joint adjustment of the camber and the longitudinal angle of inclination of the axis of rotation of the wheels on cars with forked suspension arms according to the required changes in the thickness of the gaskets under one forked lever bolt calculated by a computer program, while the method is aimed at obtaining calculation results in a predetermined, fairly wide range of deviations of the angles installation of wheels (CC) from the preferred values of the wheel settings considered by the vehicle manufacturer and allows you to change the range of permissible deviations of the installation parameters of the wheels.

However, this method is not without drawbacks. So, for example, when adjusting the CID, difficulties arise in calculating the determination of the thickness of gaskets, especially for asymmetric configurations of fork arms. Therefore, it is required to use additional information in the database of specifications, and also there is a need for additional "fine tuning" of the system. The method involves obtaining information and performing adjustment work, first for one and then for the other car wheel, which is associated with an increase in the complexity of the work. Also, when reducing or increasing the range of deviations, difficulties and errors in wheel installation may occur, it is not possible to take into account the initial thickness of the adjusting gaskets, there are no restrictions on the permissible thickness of the gaskets and the permissible difference in their thickness under the front and rear bolts of the fork lever.

The technical result of the invention is to expand the functionality of the method, allowing to determine the numerical values of the parameters of the technical effects when adjusting the installation parameters of the wheels of the car, as well as reducing the complexity of the work during maintenance of the chassis of the car.

To achieve the technical result in the proposed method for determining the parameters of technical effects when installing the wheels of a car, which consists in determining the necessary adjusting actions when changing the camber and the longitudinal angle of the axis of rotation of the wheel from the corresponding change in the values of the adjusting elements using computer software, a new is that prior to adjustment, the set numerical values of the wheel setting parameters are introduced into the simulation model and asschityvayut numerical values of parameters of the technical effects in accordance with the solution proposed by the equations.

The invention is illustrated by drawings: in Fig. 1 is a diagram of an arrangement of camber adjusting devices and a longitudinal tilt angle of an axis of turns in a suspension with fork arms; figure 2 - camber α and the longitudinal angle of inclination of the axis of rotation γ of the wheel; figure 3 - arrangement of the adjusting elements of the bracket cross and fork fork suspension; figure 4 is a nomogram of the selection of technological influences when jointly adjusting the camber angles α and the longitudinal inclination of the axis of rotation γ of the car wheel.

The simulation model is based on the mathematical dependence of the change in the geometric parameters of the adjusting elements X ₁ , X ₂ and the corresponding changes in the camber and the longitudinal angle of inclination of the axis of rotation of the wheel. Simulation of the process of changing the values of adjusting parameters and wheel installation parameters under specified conditions, taking into account restrictions, is carried out using special or standard software.

In general, a simulation model of the process of joint adjustment of the camber and the longitudinal angle of inclination of the axis of rotation of one wheel for suspensions with fork arms with upper or lower arrangement of adjusting elements and various configuration of the suspension arms is described by a system of equations

$$\begin{array}{c}\Delta \alpha ={\mathrm{<figure-callout\; id="0"\; label="A"\; filenames="00000018.png"\; state="\{\{state\}\}">A</figure-callout>}}_0\cdot \Delta M+A_{\mathrm{one}}\cdot \Delta X_{\mathrm{one}}+{\mathrm{<figure-callout\; id="2"\; label="A"\; filenames="00000017.png"\; state="\{\{state\}\}">A</figure-callout>}}_2\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_2+A_3\cdot \Delta X_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_2+A_{\mathrm{four}}\cdot \Delta X_{\mathrm{one}}^2+A_5\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_2^2+A_6\cdot \Delta X_{\mathrm{one}}^2\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_2+A_7\cdot \Delta X_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_2^2\\ \Delta \gamma ={\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_0\cdot \Delta M+B_{\mathrm{one}}\cdot \Delta X_{\mathrm{one}}+{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="00000017.png"\; state="\{\{state\}\}">B</figure-callout>}}_2\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_2+B_3\cdot \Delta X_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_2+B_{\mathrm{four}}\cdot \Delta X_{\mathrm{one}}^2+{\mathrm{<figure-callout\; id="5"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_5\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_2^2+B_6\cdot \Delta X_{\mathrm{one}}^2\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_2+B_7\cdot \Delta X_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; X"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_2^2\end{array}\},\left(\mathrm{one}\right)$$

where Δα is the magnitude of the change in camber;

Δγ is the magnitude of the change in the longitudinal angle of inclination of the axis of rotation of the wheel;

ΔM is the deviation of the actual average value of the thickness of the gaskets under the front and rear bolts of the fork arm from their adopted standard average value;

A _k - sensitivity coefficients of the equations of the system for changing the camber of the wheel;

B _k - sensitivity coefficients of the equations of the system for changing the longitudinal angle of inclination of the axis of rotation of the wheel;

ΔX _i - the amount of change in the thickness of the gaskets under the i-th adjusting bolt

wheel devices.

A simulation model of the process of joint adjustment of the camber and the longitudinal angle of inclination of the axis of rotation of the wheel for suspensions with fork arms with upper or lower arrangement of adjusting elements and various configuration of the suspension arms for both wheels of one axis is described by a system of equations

$$\begin{array}{c}\Delta {\alpha }_{\mathrm{one}}={\mathrm{<figure-callout\; id="0"\; label="A"\; filenames="00000018.png"\; state="\{\{state\}\}">A</figure-callout>}}_0\Delta M_{\mathrm{one}}+A_{\mathrm{one}}\cdot \Delta X_{\mathrm{eleven}}+A_2\cdot \Delta X_{21}+A_3\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}+A_{\mathrm{four}}\cdot \Delta X_{\mathrm{eleven}}^2+A_5\cdot \Delta X_{21}^2+A_6\cdot \Delta X_{\mathrm{eleven}}^2\cdot \Delta X_{21}+A_7\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}^2\\ \Delta {\gamma }_{\mathrm{one}}={\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_0\cdot \Delta M_{\mathrm{one}}+B_{\mathrm{one}}\cdot \Delta X_{\mathrm{eleven}}+{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="00000017.png"\; state="\{\{state\}\}">B</figure-callout>}}_2\cdot \Delta X_{21}+B_3\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}+B_{\mathrm{four}}\cdot \Delta X_{\mathrm{eleven}}^2+{\mathrm{<figure-callout\; id="5"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_5\cdot \Delta X_{21}^2+B_6\cdot \Delta X_{\mathrm{eleven}}^2\cdot \Delta X_{21}+B_7\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}^2\\ \mathrm{<figure-callout\; id="2"\; label="\Delta \; \alpha "\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{\alpha }_{}{}_2={\mathrm{<figure-callout\; id="0"\; label="A"\; filenames="00000018.png"\; state="\{\{state\}\}">A</figure-callout>}}_0\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; M"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{M}_{}{}_2+A_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}+A_2\cdot \Delta X_{22}+A_3\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}\cdot \Delta X_{22}+A_{\mathrm{four}}\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_{12}^2+A_5\cdot \Delta X_{22}^2+A_6\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_{12}^2\cdot \Delta X_{22}+A_7\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}\cdot \Delta X_{22}^2\\ \mathrm{<figure-callout\; id="2"\; label="\Delta \; \gamma "\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{\gamma }_{}{}_2={\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_0\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; M"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{M}_{}{}_2+B_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}+{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="00000017.png"\; state="\{\{state\}\}">B</figure-callout>}}_2\cdot \Delta X_{21}+B_3\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}\cdot \Delta X_{22}+B_{\mathrm{four}}\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_{12}^2+{\mathrm{<figure-callout\; id="5"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_5\cdot \Delta X_{22}^2+B_6\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}^{}{}_{12}^2\cdot \Delta X_{22}+B_7\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}\cdot \Delta X_{22}^2\end{array}\}\left(2\right)$$

where Δα is the change in the collapse of the j-th wheel;

Δγ _j is the change in the longitudinal angle of inclination of the axis of rotation of the j-th wheel;

ΔM _j is the deviation of the actual average value of the thickness of the gaskets under the i-th bolts of the fork lever of the j-th wheel from their adopted standard average value;

A _k - sensitivity coefficients of the equations of the system for changing the camber of the wheel;

B _k - sensitivity coefficients of the equations of the system for changing the longitudinal angle of inclination of the axis of rotation of the wheel;

ΔX _ij is the amount of change in the thickness of the gaskets under the i-th bolt of the j-th wheel.

The deviation of the actual average value of the thickness of the gaskets under the i-th bolts of the forked arm of the j-th wheel from their adopted standard average value is determined by the formula

$$\Delta M_j=\frac{X_{\mathrm{one}j}-X_{2j}}{2}-M,\left(3\right)$$

where M is the accepted standard average value of the thickness of the shims under the fork lever bolts (half the average distance between the connectors of the fork lever adjustment device).

The proposed method is implemented as follows. The procedure for joint adjustment of the camber and the longitudinal angle of inclination of the axis of rotation of the wheels on the fork suspension arms for a specific car model consists in creating a simulation model, preparatory work for using a simulation model, using a simulation model to determine the parameters of technical effects and performing adjustment and fixing works.

Creating a simulation model:

- data collection on the ratio of changes in the thickness of the adjusting gaskets under the front and rear forks of the forked lever and changes in the camber and longitudinal angle of inclination of the axis of rotation with a known deviation of the average thickness of the adjusting gaskets under the front and rear bolts of the adjusting device of the fork lever from their adopted initial thickness;

- presentation of data in accordance with the plan of a full two-factor experiment with a central point. In this case, you can use the data of the car manufacturer (Table 1), or the data of experimental laboratory tests, or data obtained in real conditions of car service;

- data input into a computer and calculation of sensitivity coefficients in the equations of system (1) of the simulation model using a special program. The simulation model remains in the memory of the computer.

Preparatory work for using the simulation model:

- input into the computer of these specifications (standards of car manufacturers according to the installation parameters of the wheels indicating the preferred values and permissible ranges of their deviations). Data remains in computer memory;

- input into the computer data on conditions and restrictions.

When calculating the parameters of technical impacts, the following conditions and limitations are taken into account:

$${\alpha }_{\mathrm{one}}={\mathrm{<figure-callout\; id="2"\; label="\alpha "\; filenames="00000017.png"\; state="\{\{state\}\}">\alpha </figure-callout>}}_2\pm {\delta }_{\mathrm{one}};\left(\mathrm{four}\right)$$

$${\gamma }_{\mathrm{one}}={\mathrm{<figure-callout\; id="2"\; label="\gamma "\; filenames="00000017.png"\; state="\{\{state\}\}">\gamma </figure-callout>}}_2\pm {\mathrm{<figure-callout\; id="2"\; label="\delta "\; filenames="00000017.png"\; state="\{\{state\}\}">\delta </figure-callout>}}_2,\left(5\right)$$

where δ ₁ - permissible calculation error in determining changes in wheel camber;

δ ₂ - permissible calculation error when determining changes in the longitudinal angle of inclination of the axis of rotation of the wheel.

Permissible deviations of the camber from the standard (preferred) value:

$${\alpha }_{nij}\le {\alpha }_N\le {\alpha }_{verh},\left(6\right)$$

where α _nij is the lower acceptable limit of the deviation of the collapse;

α _verh is the upper permissible limit of camber deviation.

Permissible deviations of the longitudinal angle of inclination of the axis of rotation of the wheel from the standard (preferred) value:

$${\gamma }_{nij}\le {\gamma }_N\le {\gamma }_{verh},\left(7\right)$$

where γ _nij is the lower permissible deviation of the longitudinal angle of inclination of the axis of rotation of the wheel;

γ _verh is the upper permissible deviation limit of the longitudinal angle of inclination of the axis of rotation of the wheel.

Permissible values of the thickness of the shims:

$$0\le X_{ij}\le X_{verh},\left(8\right)$$

where X _verh is the upper allowable thickness of the shims.

Enter data on the permissible range of changes in the thickness of the adjusting gaskets, data on the allowable difference in the thickness of the adjusting gaskets under the front and rear bolts of the adjusting device of the fork lever, data on the allowable difference in camber and longitudinal angle of inclination of the axis of rotation between the wheels of one axle of the car, data on the required accuracy of the results calculations for the collapse, the angle of inclination of the axis of rotation of the wheels and the thickness of the shims. Data remains in computer memory.

Using a simulation model to determine the parameters of technical influences:

- place the car at the control station for the installation parameters of the car wheels and install the front wheels in the middle of the rotary platforms of the stand;

- measure by any known method and enter into the computer the actual data on the camber and the longitudinal angle of inclination of the axis of rotation of the wheels of one axis of the car;

- measure by any known method and enter into the computer the actual data on the thickness of the adjusting gaskets under the bolts of the adjusting devices of the wheels of one axis of the car;

- calculate the necessary changes in the camber and the longitudinal angle of inclination of the axis of rotation of the wheels of one axis of the car as the difference between the actual values of these parameters and their preferred values (automatically done using the simulation model).

For the camber of the wheel, the required change is determined from the expression:

$$\Delta {\alpha }_j={\alpha }_{jf}-{\alpha }_N,\left(9\right)$$

where α _jf is the actual measured value of the collapse of the j-th wheel;

α _N - regulatory (preferred) value of the camber.

The required change in the longitudinal angle of inclination of the axis of rotation of the wheel is determined from the expression:

$$\Delta {\gamma }_j={\gamma }_{jf}-{\gamma }_N,\left(10\right)$$

where γ _if is the actual measured value of the collapse of the j-th wheel;

γ _N - normative (preferred) value of the longitudinal angle of inclination of the axis of rotation of the wheel.

When calculating the parameters of technical impacts, the conditions and restrictions on the expressions (4) - (8) are taken into account.

Using a simulation model to determine the parameters of technical impacts.

The calculation of the necessary change in the thickness of the adjusting gaskets under the front and rear bolts of the adjusting device of the fork lever for the wheels of one axle of the car is carried out by selecting on a computer using a simulation model such values of the thickness of the adjusting gaskets under the front and rear bolts of the adjusting device of the lever, at which the left and right side of the equations of system (2).

For forked control levers with a symmetrical configuration of the hinged suspension arms, the simulation model of the process of adjusting the camber and the longitudinal angle of the axis of rotation of the wheels of one axis when calculating the coefficients A _k , B _k according to the system of equations (2) is simplified to the system of equations

$$\begin{array}{c}\Delta {\alpha }_{\mathrm{one}}=A_0\cdot \Delta M_{\mathrm{one}}++A_{\mathrm{one}}\cdot \Delta X_{\mathrm{eleven}}+A_2\cdot \Delta X_{21}\\ \Delta {\gamma }_{\mathrm{one}}={\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_0\cdot \Delta M_{\mathrm{one}}+B_{\mathrm{one}}\cdot \Delta X_{\mathrm{eleven}}+{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="00000017.png"\; state="\{\{state\}\}">B</figure-callout>}}_2\cdot \Delta X_{21}\\ \Delta {\mathrm{<figure-callout\; id="2"\; label="\alpha "\; filenames="00000017.png"\; state="\{\{state\}\}">\alpha </figure-callout>}}_2=A_0\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; M"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{M}_{}{}_2+A_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}+A_2\cdot \Delta X_{22}\\ \Delta {\mathrm{<figure-callout\; id="2"\; label="\gamma "\; filenames="00000017.png"\; state="\{\{state\}\}">\gamma </figure-callout>}}_2={\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="00000018.png"\; state="\{\{state\}\}">B</figure-callout>}}_0\cdot \mathrm{<figure-callout\; id="2"\; label="\Delta \; M"\; filenames="00000017.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{M}_{}{}_2+B_{\mathrm{one}}\cdot \mathrm{<figure-callout\; id="12"\; label="\Delta \; X"\; filenames="00000018.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{X}_{}{}_{12}+{\mathrm{<figure-callout\; id="2"\; label="B"\; filenames="00000017.png"\; state="\{\{state\}\}">B</figure-callout>}}_2\cdot \Delta X_{22}\end{array}\},\left(\mathrm{eleven}\right)$$

where Δα _j is the change in the collapse of the j-th wheel;

Δγ _j is the change in the longitudinal angle of inclination of the axis of rotation of the j-th wheel;

ΔM _j is the deviation of the actual average value of the thickness of the gaskets under the i-th bolts of the fork arm of the j-th wheel from their adopted standard average value of M;

A _k - sensitivity coefficients of the equations of the system for changing the camber of the wheel;

B _k - sensitivity coefficients of the equations of the system for changing the longitudinal angle of inclination of the axis of rotation of the wheel;

ΔX _ij is the amount of change in the thickness of the gaskets under the i-th bolt of the j-th wheel.

Wheel alignment and longitudinal tilt adjustment:

- weaken the fastening of the bolts of the adjusting device and change the thickness of the adjusting gaskets under the front and rear bolts (Figure 3) of the forked levers of the wheels of one axle of the car by setting additional gaskets or removing them in accordance with the calculations (it is convenient to carry out the work when the wheels of the car are suspended);

- perform fixing work in compliance with the requirements of technical conditions;

- if the adjustment was performed on the posted wheels of the front axle, then lower the car and set the front wheels of the car in the middle of the turntable of the stand;

- measure the values of the camber and the longitudinal angle of inclination of the axis of rotation for the wheels of one axis of the car and record the results of the camber, the longitudinal angle of inclination of the axis of rotation, the thickness of the shims under the fork arm bolts before and after the adjustment work using one of the known methods.

When performing adjustment work for both axles, the adjustment for the rear wheels of the vehicle is first performed.

The method is suitable for automobiles having adjusting elements of various designs with measurable numerical values of their geometric parameters. It can be used for cars with McPherson suspension, in which the axles of rotation of the wheels are changed using longitudinal braces. In this case, it is enough to have the established dependencies between the change in the total thickness of the gaskets in the front and rear parts of the stretch marks and the change in the longitudinal angle of inclination of the axis of the rotary strut, since the camber of the wheel is controlled by turning the eccentric belt of the bolt at the junction of the shock absorber strut with the steering knuckle.

An example of calculations using a simulation model.

The parameters were determined for fork levers with insert washers. The simulation model was compiled according to the initial data of Table 1, under the assumption that these data were obtained at ΔМ = 0.75.

A simulation model of the relationship between the change in the thickness of the adjusting shims ΔX _ij and the change in the installation parameters of the wheels Δα _{j is} described by the system of equations:

$$\begin{array}{c}\Delta {\alpha }_{\mathrm{one}}=-2\cdot \Delta M-10.0\cdot \Delta X_{\mathrm{eleven}}+\mathrm{20,4}\cdot \Delta X_{21}-2.6\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}+2.6\cdot \Delta X_{\mathrm{eleven}}^2+2.6\cdot \Delta X_{21}^2+\mathrm{3,1}\cdot \Delta X_{\mathrm{eleven}}^2\cdot \Delta X_{21}-\mathrm{1,0}\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}^2\\ \Delta {\alpha }_2=-2\cdot \Delta M-10.0\cdot \Delta X_{12}+\mathrm{20,4}\cdot \Delta X_{22}-2.6\cdot \Delta X_{12}\cdot \Delta X_{22}+2.6\cdot \Delta X_{12}^2+2.6\cdot \Delta X_{22}^2+\mathrm{3,1}\cdot \Delta X_{12}^2\cdot \Delta X_{22}-\mathrm{1,0}\cdot \Delta X_{12}\cdot \Delta X_{22}^2\\ \Delta {\gamma }_{\mathrm{one}}=\mathrm{1,1}\cdot \Delta M+\mathrm{27,2}\cdot \Delta X_{\mathrm{eleven}}-33.7\cdot \Delta X_{21}+\mathrm{1,5}\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}-\mathrm{1,5}\cdot \Delta X_{\mathrm{eleven}}^2-\mathrm{1,5}\cdot \Delta X_{21}^2+10.6\cdot \Delta X_{\mathrm{eleven}}^2\cdot \Delta X_{21}+\mathrm{1,0}\cdot \Delta X_{\mathrm{eleven}}\cdot \Delta X_{21}^2\\ \Delta {\gamma }_2=\mathrm{1,1}\cdot \Delta M+\mathrm{27,2}\cdot \Delta X_{12}-33.7\cdot \Delta X_{22}+\mathrm{1,5}\cdot \Delta X_{12}\cdot \Delta X_{22}-\mathrm{1,5}\cdot \Delta X_{12}^2-\mathrm{1,5}\cdot \Delta X_{22}^2+10.6\cdot \Delta X_{12}^2\cdot \Delta X_{22}+\mathrm{1,0}\cdot \Delta X_{12}\cdot \Delta X_{22}^2\end{array}\},\left(12\right)$$

where A _K , B _K are the sensitivity coefficients of the equations;

Δx _IJ - change in the thickness of the shims under the i-th bolt of the j-th wheel.

All odds are significant. The data are presented in table.2-7.

table 2 The initial calculation data common to the left and right wheels of the car AN GN AVERH Anij Gverh GNJ M XVERH Xnij 40 180 70 10 210 150 5,0 10.0 0,0

Designations:

AN is the average standard value of the camber;

GN is the average normative value of the longitudinal tilt angle of rotation of the axis of the wheel;

AVERH - upper allowable value of camber;

ANIJ - lower allowable value of camber;

GVERH - upper allowable value of the longitudinal angle of inclination of the axis of rotation of the wheel;

GNJ - lower permissible value of the longitudinal angle of inclination of the axis of rotation of the wheel;

M is the normative value of half the thickness of the gaskets under the front and rear bolts of the fork lever;

XVERH - upper permissible value of the thickness of the gaskets;

XNIJ lower permissible value of the thickness of the gaskets;

Table 3 The initial calculation data common to the left and right wheels of the car DA Dg Dx Aosh Gosh 1,0 1,0 10.0 1,0 1,0

Designations:

DA is the permissible difference between the values of the collapse of the left and right wheels of the front axle of the vehicle;

DG is the allowable difference in the values of the longitudinal angle of inclination of the axis of rotation of the left and right wheels of the front axle of the vehicle;

DX - allowable difference in the thickness of the gaskets under the front and rear bolts of the fork lever;

AOSH - permissible error in calculating the definition of camber;

GOSH - permissible error in the calculation of determining the longitudinal angle of inclination of the axis of rotation of the wheel.

Table 4 Initial calculation data for the left wheel of the car A1F G1f X11F X21F 32 198 5.75 5.75

Table 5 Initial calculation data for the right wheel of the car A2F G2f X12F X22F 59 186 5.75 5.75

Designations:

A1F, A2F - the initial actual value of the collapse of the left and right wheels;

G1F, G2F - the initial actual value of the longitudinal angle of inclination of the axis of rotation of the left and right wheels;

X11F, X12F - initial actual value of the thickness of the gaskets under the front fork bolt for the left and right wheels;

X21F, X22F - initial actual value of the thickness of the gaskets under the rear fork lever bolt for the left and right wheels;

Table 6 Results of calculations for the left wheel Dx11 Dx21 X11R X21R DA1R DG1R A1R G1r -0.31 0.29 5.44 6.04 8.1 -17.9 40.1 180.1

Table 7 Right wheel calculation results Dx12 Dx22 X12R X22R DA2R DG2R A2R G2r -1.05 -1.34 4.70 4.41 -19.0 -6.09 40,0 180.0

Designations:

X11R, X21R - the estimated thickness of the gaskets under the front and rear bolts of the fork lever for the left wheel;

X12R, X22R - the estimated thickness of the gaskets under the front and rear fork lever bolts for the right wheel;

DA1R, DA2R - calculated change in the collapse of the left and right wheels, respectively;

DG1R, DG1R - calculated change in the longitudinal angle of inclination of the axis of rotation of the left and right wheels;

A1R, A2R - calculated value of the collapse of the left and right wheels, respectively;

G1R, G2R - calculated value of the longitudinal angle of inclination of the axis of rotation of the left and right wheels, respectively.

From the presented example, we can conclude that the results of calculations using the proposed method for determining the parameters of technical impacts when adjusting the camber and the longitudinal tilt of the axis of rotation of the wheels of the car show its sufficient effectiveness: the results of adjusting the installation parameters of the wheels are close to the preferred values; the calculation results can be used when jointly adjusting the camber and the longitudinal angle of inclination of the axis of rotation of the wheels of the front axle of the car at one time technical impacts.

The proposed method has the following advantages:

- allows you to get the results of calculations of the parameters of technical effects when adjusting the installation parameters of the wheels with any degree of accuracy;

- takes into account the initial, adopted as a normative, thickness of the adjusting gaskets under the front and rear bolts of the adjusting device of the forked suspension arm of the vehicle;

- takes into account the limitations in the permissible thickness of the adjusting gaskets and their permissible difference under the front and rear bolts of the fork lever, as well as the permissible difference in the values of the installation parameters for the left and right wheels of the car;

- allows you to obtain information about the necessary specific technical influences when jointly adjusting the camber and the longitudinal angle of inclination of the axis of rotation to achieve the "preferred" values of the considered parameters at one time of technical influences for both wheels of the same vehicle axis;

- when the installation parameters of the wheels are beyond the specifications, and the values of the adjusting elements limited by their permissible thickness, the method allows to obtain information about the necessary operations in one step of technical actions for both wheels of one axis of the car;

- to obtain a simulation model to describe the process of adjusting the camber and the longitudinal angle of inclination of the axis of rotation of the wheels, it is enough to have the information of the car manufacturers according to the plan of the full factorial experiment “with a central point” (Table 1) with a known initial thickness of the shims;

- suitable for cars with adjustable wheel mounting parameters with a numerical assessment of the parameters of adjusting devices, for example, adjusting the fork levers of a symmetrical and asymmetric configuration of the front and rear axles of the car using insert washers, grooves, cams, cones, and also for adjusting the position of the longitudinal tilt angle shock absorber struts using stretch marks in the MacPherson struts of the car;

- obtaining and improving the simulation model by calculating the sensitivity coefficients of the equations, in the absence of the manufacturer’s experimental data, by entering into the computer actual reliable data on the correspondence of the change in the installation angles of the wheels from changes in the parameters of the adjusting elements obtained when servicing cars in real operating conditions;

- to implement the method on cars with adjustable wheel settings, you can use a PC with standard software or on specialized computer stands by entering additional software.

Claims (1)

The method of determining the parameters of technical actions when installing the wheels of a car, which consists in determining the necessary adjusting actions when changing the camber and the longitudinal angle of inclination of the axis of rotation of the wheel from the corresponding change in the values of the adjusting elements using computer software, characterized in that the set numerical values before adjustment the values of the installation parameters of the wheels are introduced into the simulation model and the numerical values of the parameters of the technical impacts are calculated adjusting a wheel suspension for a different arrangement of the adjustment elements and the configuration of the suspension arm in accordance with the decision equations:

where Δα is the magnitude of the change in camber;
Δγ is the magnitude of the change in the longitudinal angle of inclination of the axis of rotation of the wheel;
ΔM is the deviation of the actual average value of the thickness of the gaskets under the front and rear bolts of the fork arm from their adopted standard average value;
A _k - sensitivity coefficients of the equations of the system for changing the camber of the wheel;
B _k - sensitivity coefficients of the equations of the system for changing the longitudinal angle of inclination of the axis of rotation of the wheel;
ΔX _i is the amount of change in the thickness of the gaskets under the i-th bolt of the wheel adjusting device,
and when adjusting both wheels of one axis - in accordance with the solution of the system of equations:

where Δα _j is the change in the collapse of the j-th wheel;
Δγ _j is the change in the longitudinal angle of inclination of the axis of rotation of the j-th wheel;
ΔM _j is the deviation of the actual average value of the thickness of the gaskets under the i-th bolts of the fork lever of the j-th wheel from their adopted standard average value;
A _k - sensitivity coefficients of the equations of the system for changing the camber of the wheel;
B _k - sensitivity coefficients of the equations of the system for changing the longitudinal angle of inclination of the axis of rotation of the wheel;
ΔX _ij is the amount of change in the thickness of the gaskets under the i-th bolt of the j-th wheel.

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