JPH06273284A - Measurement of wheel alignment of automobile - Google Patents

Abstract

PURPOSE:To make possible the toe adjustment in consideration of the value of camber by measuring the toe and camber of each wheel by a measurement unit which is individually installed in correspond to each wheel of an automobile and carrying out the wheel alignment adjustment. CONSTITUTION:Each measurement unit 1A-1D presses a roller supporting body 6 equipped with a plurality of rollers 5 to a wheel W, and measures the tilt of the supporting body 6 by revolving the wheel W, and the actual measurement values of the toe and camber are outputted into a personal computer 2 for calculating the toe and camber. The personal computer 2 judges the correctness by comparing and collating if each of the actual measurement value of chamber, the calculated optimum toe value, lateral difference between the left and right wheels of the actual measurement value of camber, and the lateral difference between the left and right wheels of the optimum value of toe is within each allowable limit or not. A personal computer 3 for instructing the targe toe adjustment value carries out the graphic processing for the incorrect items among the actual measurement value of camber, optimum toe value, and the result of the correctness judgement of each value, and the result of the processing is outputted on a target toe adjustment value display monitor 4 and displayed in a visible manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wheel alignment adjustment of an automobile, and more particularly to a wheel alignment measuring method for measuring the toe and camber of each wheel prior to the toe adjustment.

[0002]

2. Description of the Related Art For measuring and adjusting wheel alignment in an automobile assembly line, many types of automobiles have a structure in which only the toe can be adjusted. Even if it is measured, only the toe is often adjusted based on the measured value (for example, Vol. 19 of Automotive Engineering, "Manufacturing Method of Automobile", April 20, 1980, Sankaido Co., Ltd., P227-). 228, “9.2.8 Tester Line”
See section).

Further, even in a structure in which the camber can be adjusted as in some vehicle types, the toe adjustment and the camber adjustment are completely independent, and the measured values of the toe and the camber are the respective target values. However, there is no established method for measuring and adjusting the wheel alignment so as to mutually correct the toe and the camber by simply performing the adjustment work independently.

Therefore, although the toe and camber of an automobile are ideally adjusted so that all of them are at the designed values, most automobiles that do not have the camber adjusting mechanism as described above have a component error. Due to the accumulation of the assembly error and the assembly error, the left and right cambers of the front and rear wheels are different from each other. Further, even in some cars having a camber adjustment mechanism, a left-right difference occurs within the allowable range. Generally, a camber tolerance of a passenger car is about ± 45 to ± 60 minutes, so that the left-right difference of the camber is about 100 minutes at maximum.

In such a case, it is necessary to change the toe value of each wheel according to the camber amount of each wheel. However, since this is impossible at present, the balance of the wheel alignment of the entire vehicle is not always sufficient. Not
The desired performance may not be obtained in terms of tire life and steering stability.

That is, FIGS. 5 and 6 show the outline of the conventional measurement and adjustment work of the wheel alignment, but after measuring the toe θ and the camber ψ of each wheel W of the vehicle B by each measuring unit 1. , Toe θ is adjusted by the toe adjustment mechanism so that θ _R = θ _L without any left-right difference.
When the camber adjusting mechanism is not provided, the value of the camber ψ becomes ψ _R ≠ ψ _L and the left and right difference remains.

Also, for a small number of automobiles having a camber adjusting mechanism, the camber ψ is ψ _R ≠ ψ _L within the allowable range.
Therefore, the toe adjustment at this time is ideally adjusted so that θ _R ≠ θ _L in consideration of the respective cambers ψ _R and ψ _L , while the toe θ _R and θ _L Will be adjusted to θ _R = θ _L irrespective of the values of camber ψ _R and ψ _L.

The present invention has been made in view of the above problems, and an object thereof is to provide a wheel alignment measuring method capable of performing toe adjustment in consideration of the camber value.

[0009]

The vehicle wheel alignment measuring method of the present invention is a method of measuring the wheel alignment of each wheel prior to the toe adjustment of the vehicle, and individually for each wheel of the vehicle. Based on the correlation data which predefines the step of measuring the toe and camber of each wheel by the provided measuring unit and the relationship between a certain camber value and the ideal toe value for the camber value, A step of calculating an optimum toe value corresponding to the actual camber value, a step of comparing and collating the actual camber value and the optimum toe value with allowable limit values for camber and toe, respectively, and determining whether the result is acceptable or not; And based on the pass / fail judgment result regarding toe,
When each value is within the allowable limit, a step of visually displaying the optimum toe value as a toe adjustment target value on the display device together with the toe actual measurement value is included.

[0010]

According to this method, the optimum toe value visually displayed as the target value for the toe adjustment takes into consideration the actual camber value in advance, so that a well-balanced wheel alignment adjustment can be performed. become.

[0011]

FIG. 2 is a schematic view of a system to which the present invention is applied, which is roughly classified into four measuring units 1A to 1D individually provided corresponding to the front and rear wheels W of a vehicle B, respectively.
Personal computer for toe-camber calculation (hereinafter referred to as personal computer for toe-camber calculation) 2, personal computer for indicating toe adjustment target value (hereinafter referred to as personal computer for indicating toe adjustment target value) 3, and toe adjustment as a display device It is composed of a target value display monitor 4.

In the measuring units 1A to 1D, for example, a roller support 6 having three or more rollers 5 is pressed against the tire side surface of each wheel W, and each wheel W is driven by a drive roller (not shown). By rotating the roller support member 6, the inclination of the roller support member 6 is continuously measured at multiple points, and finally the average value of these values is output as the measured values of the toe θ and the camber ψ. Of course, as the measurement units 1A to 1D, non-contact type units using a laser distance measuring sensor or the like can be used.

When the vehicle B to be measured is driven to a predetermined measurement position and the measurement start button is operated as shown in FIG. 1 (step S1 in FIG. 1), each wheel W
The corresponding measurement units 1A to 1D measure the toe θ and the camber ψ (step S2), and the measured values of the toe θ and the camber ψ for each wheel W are taken into the toe-camber computing personal computer 2.

On the other hand, as shown in FIG. 3, there is a correlation (theoretical characteristic value) between the value of a certain camber ψ and the ideal value of the toe θ for it, This relationship is expressed by the correlation function θ = f between the toe θ and the camber ψ.
(Ψ) is stored in advance in the storage unit of the toe-camber calculation personal computer 2 for each vehicle type.

Then, as described above, when the measured values regarding the toe θ and the camber ψ are input to the toe-camber calculation personal computer 2 together with the vehicle type information (step S2,
S3), in the toe-camber calculation personal computer 2, the actual camber value for each wheel W is applied to the correlation function formula θ = f (ψ) of the corresponding vehicle type, and is made ideal for the actual camber value. The optimum toe value is calculated for each wheel W (step S4).

As shown in FIG. 4, the toe-camber computing personal computer 2 has a maximum design value ψ _max and a minimum designable value ψ _min regarding the camber ψ for each vehicle type, and a design regarding the toe. The maximum allowable value θ _max and the minimum allowable value θ _min , the maximum allowable value ψ _D of the camber left-right difference, and the maximum allowable value θ _D of the toe left-right difference are stored in advance.

When the ideal optimum toe value is calculated with respect to the actual camber value for each wheel W as described above, the toe-camber calculation personal computer 2 calculates the actual camber value. The optimum toe value, the left and right difference between the left and right wheels of the actual camber value, and the left and right difference between the left and right wheels of the toe optimum value are compared and compared to determine whether the results are acceptable or not. (Step S5).

For example, the measured actual camber value of the right front wheel W (FRRW) is ψ _R , the measured actual camber value of the left front wheel W (FRLW) is ψ _L, and the optimum toe value of the right front wheel W obtained by calculation is θ. _R , similarly, when the optimum toe value of the left front wheel W is θ _L , in the toe-camber calculation personal computer 2, the actual camber measured values ψ _R and ψ _L are ψ in FIG.
Whether or not it is in the range from _max to ψ _min is checked, and the left-right difference between the camber measured values ψ _R and ψ _L is ψ _d = ψ _R − ψ _L
Check whether is less than or equal to the maximum allowable value ψ _D. Furthermore, it is checked whether the values of the optimum toe values θ _R = f (ψ _R ) and θ _L = f (ψ _L ) are in the range of θ _max to θ _min , and the optimum toe values θ _R and θ _L Left-right difference θ _d = θ _R −
Check if θ _L is less than the maximum allowable value θ _D.

In this way, when each value is compared with the allowable limit value, the toe-camber computing personal computer 2 is
The pass / fail judgment result is output to the personal computer 3 for instructing the toe adjustment target in FIG. 2 together with the toe actual measurement value for each wheel W obtained by the measurement and the optimum toe value for each wheel W obtained by the calculation. .

On the other hand, the personal computer 3 for instructing the toe adjustment target value carries out a graphic process for the rejected items of the actual camber value, the optimum toe value, and the pass / fail judgment result of each value (step S6). The result is output to the toe adjustment target value display monitor 4 of FIG. 2 to be visually displayed (step S7).

That is, in the toe adjustment target value instructing personal computer 3, the input optimum toe value is provided with a certain permissible range within the permissible limit value of FIG. When graphic-processed and sent to the toe adjustment target value display monitor 4, a band-shaped toe adjustment target value mark 7 having a certain width is displayed on the screen of the toe adjustment target value display monitor 4, as shown in FIG. Each wheel W is visually displayed, and at the same time, a finger-line toe actual measurement mark 8 is visually displayed for each wheel W.

In this case, as a result of comparing the above-mentioned actual camber value, optimum toe value, camber left / right difference, and toe left / right difference with the allowable limit values, if any of the items deviates from the allowable range, that is, In the example, θ _L , θ _R , ψ
_{If any of L} , ψ _R , θ _d , and ψ _d fails, the above toe adjustment target value and toe actual measurement value are not displayed, and the items and contents of the failure are displayed. As shown in 7, the toe adjustment target value display monitor 4 visually displays. For example, when ψ _L exceeds ψ _min , the display as shown in FIG. 7A is made, and ψ _R exceeds ψ _max and θ _R exceeds θ _max . In this case, the display as shown in FIG. 7B is displayed.

While looking at the screen of the toe adjustment target value display monitor 4, the worker makes an adjustment so that the actual toe adjustment value falls within the range of the toe adjustment target value (step S8,
S9). At this time, since the toe actual measurement value mark 8 on the screen of the toe adjustment target value display monitor 4 moves in real time as the toe is adjusted, the operator sets the toe actual measurement value mark 8 to the toe adjustment target value mark 7. It should be adjusted so that it falls within the range.

On the other hand, the toe adjustment target value display monitor 4
If specific items that deviate from the permissible limit value and their contents are displayed on the screen, the operator needs to adjust the toe because the vehicle needs to be repaired, such as parts replacement. Instead, the worker attaches a label or the like to the vehicle B as a marking process indicating that the vehicle correction work is necessary (steps S8 and S10).

[0025]

As described above, according to the present invention, the toe and camber of each wheel are measured, and the optimum toe value that is ideal with respect to the actual measured camber value is defined as correlation data in advance. After calculating the optimum toe value as the toe adjustment target value together with the toe actual measurement value, the left and right sides are blindly the same for the camber in which a left-right difference is inevitable during toe adjustment. Adjust the toe value so that the balance of the vehicle is not lost, and the toe value is adjusted after knowing the optimum toe value for the actual camber value of each wheel. As a result, the wheel alignment of the entire vehicle is well balanced, and the tire life and steering stability can be improved.

[Brief description of drawings]

FIG. 1 is a flowchart of a measurement processing procedure showing an embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of a wheel alignment measurement / adjustment system that executes the procedure of FIG.

FIG. 3 is an explanatory diagram showing a correlation between a camber value and an ideal toe value for the camber value.

FIG. 4 is an explanatory diagram showing a relationship between each value of a toe, a camber, and their left-right difference and an allowable limit value.

FIG. 5 is an explanatory plan view of a conventional wheel alignment measurement / adjustment system.

FIG. 6 is a front explanatory view of FIG.

FIG. 7 is an explanatory diagram of a display state of a toe adjustment target value display monitor.

[Explanation of symbols]

 1A, 1B, 1C, 1D ... Measuring unit 2 ... Toe camber calculation personal computer 3 ... Toe adjustment target value instruction personal computer 4 ... Toe adjustment target value display monitor (display device) 7 ... Toe adjustment target value mark 8 ... Toe actual measurement mark B ... Vehicle (automobile) W ... Wheel

Claims (1)

[Claims] 1. A method for measuring the wheel alignment of each wheel prior to adjusting the toe of the vehicle, wherein the toe and camber of each wheel are measured by a measuring unit individually provided for each wheel of the vehicle. And a step of calculating an optimum toe value corresponding to the actual camber value based on correlation data that predefines a relationship between a certain camber value and an ideal toe value for the camber value, Comparing and collating the actual camber value and the optimum toe value with allowable limit values for camber and toe, respectively, and determining pass / fail; and based on the result of pass / fail judgment for the camber and toe, each value is an allowable limit. If it is within the range, the step of visually displaying the optimum toe value together with the actual toe value on the display device as the toe adjustment target value, Wheel alignment measurement method of a motor vehicle, wherein the Mukoto.