JP5894318B1 - Wheel alignment inspection method - Google Patents

Abstract

An object of the present invention is to appropriately inspect the cause of a defect in wheel alignment. The setback and the caster angle γ1 of the right front wheel and the caster angle γ2 of the left front wheel are measured in a state where Tf1 and Tf2 are approximately equal and Tr1 and Tr2 are approximately equal. When the setback is greater than or equal to a predetermined size, either of the front suspension device 10 and the rear suspension device 20 has a cause of setback based on the fact that | γ1−γ2 | is greater than or equal to the predetermined size. To evaluate. Further, based on whether γ1 or γ2 is abnormal, it is evaluated which of the left side part and the right side part of the parts of the front suspension device 10 has a problem. [Selection] Figure 1

Description

The present invention relates to a wheel alignment inspection method.

  Adjustment of wheel alignment in a vehicle having four wheels such as an automobile is important in order to ensure stability during traveling and to suppress uneven wear of tires. In Patent Document 1, the steering wheel is positioned in a horizontal position and attached to the steering shaft while adjusting the direction of the front wheel based on the assumed direction of the rear wheel, and then the toe of the front wheel and the rear wheel is adjusted.

JP2012-122900A

  The present inventor has realized that even when the wheel alignment is adjusted as in Patent Document 1, stability during traveling may not be ensured. And even if it seems that wheel alignment can be adjusted properly at first glance, the reason why the stability during driving cannot be secured is that the cause of the wheel alignment failure cannot be properly grasped, The reason is that the cause cannot be properly eliminated.

  An object of the present invention is to provide a wheel alignment inspection method capable of appropriately inspecting the cause of a defect in wheel alignment.

  The present inventor, when there is a defect in the wheel alignment in the past, apparently adjusts the front wheel or rear wheel toe, setback, caster, etc. to the normal value range without examining the cause in detail. I thought there was a problem. Therefore, as a result of intensive research to appropriately inspect the cause of the wheel alignment defect, the following invention has been achieved.

In the wheel alignment inspection method according to the present invention, when there is a left / right difference in at least one individual toe of the front wheel and the rear wheel , the toe is adjusted so as to eliminate the left / right difference, and then the individual toe of the front wheel and the rear wheel is adjusted . Measure the setback and the casters of the left front wheel and the right front wheel in a state where there is no difference between the left and right, and the setback is larger than a predetermined size , and there is a difference between the left and right casters. If there is a problem, the left front wheel or right front wheel caster is evaluated to determine whether the cause of the setback is in the left or right part of the front suspension.

  According to the conventional concept of wheel alignment adjustment, the toe, setback, and casters are apparently adjusted for the time being. For this reason, even if the cause of the setback appears on the caster, the cause cannot be obtained by adjusting the caster to the normal value by mistake. On the other hand, according to the wheel alignment inspection method of the present invention, it is assumed that there is no difference between the left and right front wheels and rear wheels, while the setback and casters are measured as they are. And, when the size of the setback is equal to or larger than a predetermined value, whether or not there is a difference between the left and right casters, and at least one of the casters of the left front wheel and the right front wheel is abnormal. Based on this, evaluate the cause of the occurrence of setback. The difference between the left and right casters on the front wheels indicates whether there is a problem with the front or rear suspension. Whether the caster of the left front wheel or the right front wheel deviates from the reference value indicates whether there is a problem in the right side portion or the left side portion of the part included in the front suspension device. For this reason, it is possible to grasp the cause of the setback. In this way, it is assumed that there is no difference between the left and right toe for the front and rear wheels, but setback and casters are not adjusted unnecessarily, and the setback is generated by measuring the current situation. The cause can be properly grasped. Note that “the state in which there is no difference between the left and right individual toes of the front wheels and the rear wheels” may indicate a state in which the difference in right and left of the individual toes is zero, or a state where the difference is equal to or less than a predetermined reference value. Also good.

In the present invention, based on whether there is an abnormality in any of the caster of left front wheel and the right front wheel, so the cause assessing whether the right or left of the site in front of the suspension system, the front side of the suspension system It is possible to appropriately evaluate whether there is a problem in the right side portion or the left side portion of the contained part. If there is a left / right difference in the individual toe, the caster is measured after correcting the difference. Therefore, it is possible to obtain an appropriate measurement value for evaluating the cause of setback.

  Further, in the present invention, it is preferable to evaluate that the cause is the rear suspension when there is no difference between the left and right casters. According to this, when there is no left-right difference in the front wheel casters, it can be appropriately evaluated that there is a problem with the rear suspension device.

1 is a schematic plan view of an automobile to be inspected by a wheel alignment inspection method according to an embodiment of the present invention. It is the figure which looked at the right front wheel from the left, and is a figure showing a caster angle. It is a flowchart which shows the flow of the test | inspection method of this wheel alignment.

  A wheel alignment inspection method (hereinafter referred to as the present inspection method) according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of an automobile 1 that is an object of this inspection method. The automobile 1 includes a left front wheel 2L and a right front wheel 2R, a left rear wheel 3L and a right rear wheel 3R, a front suspension device 10, and a rear suspension device 20.

  The front suspension device 10 is, for example, an independent suspension device, and includes a knuckle that rotatably supports the front wheels 2L or 2R, and left and right wheel support portions including an upper arm and a lower arm that connect and support the knuckle with a vehicle body frame, A stabilizer that connects the left and right wheel support portions, a tension rod that has a rear end connected to each of the left and right sides of the wheel support portion, and a front end connected to the vehicle body frame. In addition, the stabilizer and the tension rod may be configured separately as described above, or may be configured integrally, and one member may have both functions.

  The rear suspension device 20 is, for example, an axle suspension type suspension device, and includes left and right axle support portions including torque rods and lower arms that support an axle fixed to the rear wheel 3L or 3R by connecting to a vehicle body frame. Have. Members constituting the rear suspension device 20 may be supported by the vehicle body frame via suspension members.

  The left front wheel 2L and the right front wheel 2R are disposed at the same position in the front-rear direction in a normal state. The left rear wheel 3L and the right rear wheel 3R are also arranged at the same position in the front-rear direction in a normal state. On the other hand, if a part of the front suspension device 10 or the rear suspension device 20 is deformed due to an accident or the like, setback may occur due to the wheel being displaced in the front-rear direction. For example, a broken line A in FIG. 1 indicates a setback when the front wheel 2R is shifted backward from a normal position, and a broken line B in FIG. 1 indicates a setback when the front wheel 2R is shifted forward from a normal position. As a result, the angle α or β between the horizontal straight line L0 orthogonal to the geometric center line C of the automobile 1 and the straight line L1 or L2 connecting the same positions of the front wheels 2L and 2R as shown in FIG. (Α> 0, β> 0) occurs. Hereinafter, such an angle is referred to as a setback angle.

  In this inspection method, the setback angle or the like is measured using an alignment tester device (hereinafter referred to as a tester). In the present embodiment, in addition to the setback angle, a tester capable of measuring the individual toes Tf1 and Tf2 of the front wheels 2L and 2R, the individual toes Tr1 and Tr2 of the rear wheels 3L and 3R, and the caster angle γ is used.

  The tester of this embodiment measures the setback angle as follows. This tester outputs the setback angle as a shift in the front-rear direction of only the right front wheel 2R, regardless of which of the front wheels 2L and 2R and the rear wheels 3L and 3R is shifted in the front-rear direction. Specifically, the tester has a longer distance in the front-rear direction between the right front wheel 2R and the right rear wheel 3R, based on the distance W in the front-rear direction between the left front wheel 2L and the left rear wheel 3L. Or whether it is short. When the distance in the front-rear direction between the right front wheel 2R and the right rear wheel 3R is shorter than W by ΔW1 (> 0), only the right front wheel 2R is virtually shifted backward by ΔW1. After that, the setback angle of the right front wheel 2R is output. At this time, the tester outputs the output value as a negative value. For example, when the virtual position of the right front wheel 2R is the position indicated by the broken line A in FIG. 1, -α is output. Further, when the distance in the front-rear direction between the right front wheel 2R and the right rear wheel 3R is longer than W by ΔW2 (> 0), only the right front wheel 2R is virtually shifted to the virtual position forward by ΔW2. After that, the setback angle of the right front wheel 2R is output. At this time, the tester outputs the output value as a positive value. For example, when the virtual position of the right front wheel 2R is the position indicated by the broken line B in FIG. 1, + β is output.

  As described above, the magnitude of the setback angle output by the tester of the present embodiment indicates the magnitude of any deviation between the front wheels 2L and 2R and the rear wheels 3L and 3R. The sign of the setback angle indicates which of the distance between the left front wheel 2L and the left rear wheel 3L and the distance between the right front wheel 2R and the right rear wheel 3R is greater. On the other hand, it is not possible to specify which of the front wheels 2L and 2R and the rear wheels 3L and 3R is displaced only by the setback measurement value output by the tester of the present embodiment. For example, it is understood that the distance between the left front wheel 2L and the left rear wheel 3L is shorter than the distance between the right front wheel 2R and the right rear wheel 3R only from the fact that the setback is positive. In this state, only the left front wheel 2L is displaced backward, only the left rear wheel 3L is displaced forward, only the right front wheel 2R is displaced forward, and only the right rear wheel 3R is rearward. It is established in any of the states that are deviated. Further, it can be understood from the fact that the setback is negative only that the distance between the left front wheel 2L and the left rear wheel 3L is longer than the distance between the right front wheel 2R and the right rear wheel 3R. In this state, only the left front wheel 2L is displaced forward, only the left rear wheel 3L is displaced backward, only the right front wheel 2R is displaced backward, and only the right rear wheel 3R is forward. It is established in any of the states that are deviated.

  The individual toes Tf1 and Tf2 measured by this tester are distances between the front ends of the front wheels 2L and 2R and the geometric center line as shown in FIG. The individual toes Tr1 and Tr2 are distances between the front ends of the rear wheels 3L and 3R and the geometric center line. The caster angle γ corresponds to an angle between the central axis of the kingpin and the vertical axis when the wheel is viewed from the lateral direction (left-right direction). In many cases, the kingpin is not actually provided. For example, when a strut-type suspension device is employed, as shown in FIG. 2, the angle between the central axis of the strut and the vertical axis corresponds to the caster angle γ. When a suspension device such as a double wishbone type is employed, the angle between the rotation center axis and the vertical axis when the wheel is rotated by cutting the handle corresponds to the caster angle γ.

  In this inspection method, first, the automobile 1 is installed on a tester as shown in S1 of FIG. Next, the individual toe Tr1 and Tr2 of the rear wheels 3L and 3R are measured by a tester (S2). Then, it is determined whether or not the magnitude of the left-right difference of the individual toe measured in S2 is 0.5 mm or more, that is, whether or not | Tr1-Tr2 | ≧ 0.5 mm is satisfied (S3). That is, it is determined whether or not there is a left / right difference in the individual toes of the rear wheels 3L and 3R. Note that whether or not there is a left-right difference in the individual toe may be determined based on a numerical value other than 0.5 mm. When it is determined that there is a left-right difference in the individual toes of the rear wheels 3L and 3R (S3, Yes), the toes of the rear wheels 3L and 3R are adjusted so as to satisfy | Tr1-Tr2 | <0.5 mm (S4). That is, the toe of the rear wheels 3L and 3R is adjusted so that there is no difference between the left and right individual toes. At this time, it is preferable to adjust the toe so that | Tr1-Tr2 | is as zero as possible. Toe adjustment is performed, for example, by repeatedly changing the toe of the rear wheels 3L and 3R and measuring the individual toe with a tester until there is no difference between the left and right of the individual toe. On the other hand, if it is determined in S3 that there is no difference between the left and right individual toes of the rear wheels 3L and 3R (S3, No), S4 is not executed and the process proceeds to S5. Even if it is determined that | Tr1-Tr2 | ≧ 0.5 mm is not satisfied, the toe may be adjusted so that | Tr1-Tr2 | is as zero as possible.

  Next, the individual toe Tf1 and Tf2 of the front wheels 2L and 2R are measured by a tester (S5). Then, it is determined whether or not the magnitude of the left-right difference of the individual toe measured in S5 is 0.5 mm or more, that is, whether or not | Tf1-Tf2 | ≧ 0.5 mm is satisfied (S6). That is, it is determined whether there is a left / right difference in the individual toes of the front wheels 2L and 2R. Note that whether or not there is a left-right difference in the individual toe may be determined based on a numerical value other than 0.5 mm. If it is determined that there is a left / right difference in the individual toes of the front wheels 2L and 2R (S6, Yes), the toes of the front wheels 2L and 2R are adjusted so as to satisfy | Tf1-Tf2 | <0.5 mm (S7). In other words, the toes of the front wheels 2L and 2R are adjusted so that there is no difference between left and right individual toes. At this time, it is preferable to adjust the toe so that | Tf1-Tf2 | is as zero as possible. The method of adjusting the front wheel toe is the same as the method of adjusting the rear wheel toe. On the other hand, when it is determined in S6 that there is no difference between the left and right individual toes of the front wheels 2L and 2R (S6, No), S7 is not executed and the process proceeds to S8. Even when it is determined that | Tf1−Tf2 | ≧ 0.5 mm is not satisfied, the toe may be adjusted so that | Tf1−Tf2 | is as zero as possible.

  Next, the caster angle γ1 of the front wheel 2L and the caster angle γ2 of the front wheel 2R are measured by a tester (S8), and the setback angle is measured (S9). Then, based on the measurement results of S8 and S9, if setback occurs, the cause is determined (S10).

  The determination method of S10 will be described in detail. First, based on whether or not the magnitude of the setback angle measured in S9 is 10 ′ (predetermined magnitude) or more, it is determined whether or not setback has occurred. It should be noted that another value other than 10 ′ may be used to determine whether or not setback has occurred. If it is determined that setback has occurred, it is based on whether or not the magnitude of the left-right difference in caster angle is 30 'or less, that is, whether | γ1-γ2 | ≦ 30' is satisfied. Then, it is determined whether the cause of the setback is in the front suspension device 10 or the rear suspension device 20. If | γ1-γ2 |> 30 ′ holds, it is determined that there is a high probability that there is a cause in the front suspension device 10, and if | γ1-γ2 | ≦ 30 ′ holds, the cause in the rear suspension device 20 It is determined that there is a high probability. The reason for adopting such conditions is as follows. According to the experience of many automobile maintenances conducted by the inventor in the past, a vehicle having (i) | γ1−γ2 | exceeding 30 ′ is more than 30 ′, even if it only exceeds 30 ′. There is a problem. (Ii) When | γ1-γ2 | is 30 ′ or less, there is no problem in the front suspension device 10. (Iii) | γ1-γ2 | may be close to 30 ′ even in a vehicle in which the front suspension 10 has no problem. From the above, whether or not | γ1−γ2 | exceeds 30 ′ is adopted as a condition for determining whether the cause of the setback is in the front suspension device 10 or the rear suspension device 20. .

  When there is a problem with the front suspension device 10, it is considered that the cause of the setback is that the right side portion or the left side portion of the tension rod, the stabilizer, or the like constituting the front suspension device 10 is stretched or damaged. When there is a problem with the front suspension device 10, the cause of the setback is acquired based on which caster angle of the left front wheel 2L or the right front wheel 2R is deviated from a normal value to a larger or smaller value. Specifically, the cause of the setback is acquired based on Table 1 below.

  The second column of Table 1 shows the sign of the measured value of the setback angle. The third column in Table 1 indicates which of the casters of the left front wheel 2L and the right front wheel 2R is abnormal.

  Whether there is an abnormality in the caster is determined as follows. The caster angle should be the initial setting value published by the manufacturer of the automobile 1 at the time of manufacture. Therefore, the closer the caster abnormality determination time is to the manufacturing time of the automobile 1, the closer the normal caster angle is to the initial set value. On the other hand, if the number of years elapsed from the time of manufacture of the automobile 1 is large, it is assumed that the caster angle is changed to a value different from the initial setting value even if there is no problem in the front suspension device 10 and the like. For example, when the usage period of the automobile 1 becomes longer, the caster may become larger as the vehicle body becomes lower due to the deterioration of the suspension over time. For this reason, it is necessary to consider that the normal value of the caster angle is larger than the initial set value depending on how much the time of the caster abnormality determination has elapsed from the time of manufacture of the automobile 1. Accordingly, in consideration of such a change in caster angle according to aging or the like, it is determined which caster angle of the front wheels 2L and 2R corresponds to a normal value. A front wheel having a different caster angle is a front wheel having an abnormal caster angle.

  According to the experience of many automobile maintenance conducted by the inventor in the past, in a normal change in caster angle due to aged deterioration or the like, the caster greatly changes so as to produce a difference of 30 'in the left-right difference of the caster angle. Absent. Therefore, when | γ1−γ2 | exceeds 30 ′, one of the casters of the left front wheel 2L and the right front wheel 2R shows a value that greatly exceeds the change in the normal caster angle due to deterioration over time. Therefore, even if the normal value prediction accuracy due to aging degradation or the like is not so high, it is easy to clarify which of the casters of the left front wheel 2L and the right front wheel 2R is abnormal. This is because the reference value of 30 'is larger than a normal caster change due to aging or the like.

  The fourth column in Table 1 indicates whether the caster having the abnormality is larger or smaller than the normal value. The fourth column of Table 1 shows whether there is a cause of setback in the left or right part of the parts of the front suspension device 10. The fifth column of Table 1 shows the direction of deviation of the front wheels due to the cause.

  The determination based on Table 1 is as follows. When the measured value of the setback angle is negative, as shown in Table 1, either the caster angle of the right front wheel 2R is smaller than the normal value or the caster angle of the left front wheel 2L is larger than the normal value. Conceivable. When the former is established, there is a high probability that the right front wheel 2R is displaced rearward due to the extension or damage of the right side part such as a tension rod or a stabilizer as a cause of setback. When the latter holds, there is a high probability that the left front wheel 2L is displaced forward due to bending or damage of the left part of the tension rod or the like as a cause of setback. When the measured value of the setback angle is positive, as shown in Table 1, it can be considered that the caster angle of the left front wheel 2L is smaller than the normal value and the caster angle of the right front wheel 2R is larger than the normal value. When the former is established, there is a high probability that the left front wheel 2L is displaced rearward due to the extension or damage of the left part of the tension rod or the like as a cause of setback. When the latter holds, there is a high probability that the right front wheel 2R is displaced forward due to bending or damage of the right side part such as a tension rod as a cause of setback. The above is the determination method when there is a problem with the front suspension device 10.

  On the other hand, when there is a problem with the rear suspension device 20, as a cause of the setback, the left side portion or the right side portion of the torque rod, the lower arm, the suspension member, etc. constituting the rear suspension device 20 is stretched or damaged. Can be considered. If there is a problem with the rear suspension device 20, the cause of the setback is acquired based on the sign of the measured value of the setback angle. If the measured value of the setback angle is negative, the cause is that the left rear wheel 3L has shifted backward due to the extension or damage of the left part of the torque rod or the like, or the right part of the right part such as the torque rod is bent or damaged. The probability that the rear wheel 3R is displaced forward is high. If the measured value of the setback angle is positive, the cause may be that the right rear wheel 3R has shifted backward due to the extension or damage of the right part of the torque rod or the like, or the left part of the left part of the torque rod or the like has been bent or damaged. The probability that the rear wheel 3L is displaced forward is high.

  According to the present embodiment described above, when there is a left / right difference between the individual toes Tf1 and Tf2 of the front wheels 2L and 2R and a left / right difference between the individual toes Tr1 and Tr2 of the rear wheels 3L and 3R, these left / right differences are eliminated. Adjust as follows. On the other hand, the setback and caster angles are measured as they are without any adjustment. When setback occurs (when the setback angle is equal to or larger than a predetermined size (10 ′)), there is also a left-right difference in the caster angles of the front wheels 2L and 2R (| γ1−γ2 | ≧ It is evaluated whether the cause of the occurrence of the setback is in the front suspension device 10 or the rear suspension device 20 based on whether or not 30 ′ is established. Further, based on which of the caster angles of the front wheels 2L and 2R is abnormal, it is acquired which of the left part and the right part of the part included in the front suspension device 10 has a problem.

  In this way, the toe of the front wheels 2L and 2R and the toe of the rear wheels 3L and 3R are assumed to have no left-right difference, but the setback and casters are not adjusted unnecessarily and are measured as they are. By doing so, it is possible to appropriately grasp the cause of the setback.

  Hereinafter, modifications of the above-described embodiment will be described. In the above-described embodiment, the caster angle is measured in order to obtain the size of the caster. However, the size of the caster may be acquired by other methods. For example, the size of the caster may be acquired by measuring the heights of the caster rail and the axle center position. The caster angle can be obtained from the angle of a triangle with (caster rail) / (axle center position height) as a tangent. In addition, it may be determined that a difference between the left and right casters of the front wheels 2L and 2R is generated by directly using (cast rail) / (axle center position height). In this case, the reference value (30 ′ and the like in the above-described embodiment) used for the determination is replaced with a value corresponding to (cast rail) / (axle center position height).

  In the above-described embodiment, the individual toe is the distance between each wheel and the geometric center line. However, individual toes may be represented by the angle of each wheel. In this case, the reference value (0.5 mm in the above-described embodiment) used for the determination based on the individual toe is replaced with a value corresponding to the wheel angle.

  Further, in the above-described embodiment, when the left and right casters of the front wheels 2L and 2R are different from each other, there is a problem in which of the left and right parts of the parts of the front suspension device 10 based on which caster is abnormal. Evaluating whether there is. However, it may be carried out independently to evaluate which of the front suspension device 10 and the rear suspension device 20 has a problem based on whether or not there is a difference between left and right casters of the front wheels 2L and 2R. Moreover, it may be independently carried out to evaluate whether there is a problem in the left or right part of the parts of the front suspension device 10 based on which of the left and right casters is abnormal. If it is determined by comparison between the caster angle and the normal value that there is an abnormality in one of the front wheels 2L and 2R, the front suspension device 10 may be evaluated as having a problem. Moreover, when it is determined that there is no abnormality in any of the casters of the front wheels 2L and 2R by comparing the caster angle with the normal value, it may be evaluated that there is a problem with the rear suspension device 20.

1 Car 2L Front wheel (Left front wheel)
2R front wheel (right front wheel)
3L Left rear wheel 3L Rear wheel (Left rear wheel)
3R rear wheel (right rear wheel)
10 Front suspension 20 Rear suspension C Geometric centerline

Claims (2)

When there is a left / right difference in at least one of the individual toes on the front and rear wheels , after adjusting the toe so that there is no difference between the left and right, there is no difference between the left and right individual toes on the front and rear wheels. in addition to measuring the setback and the front left wheel and the right front wheel of the caster, even if setback is predetermined magnitude or more, when the difference between the left and right to the front wheel caster is occurring, the left front wheel and right front wheel A wheel alignment inspection method characterized in that , based on which caster has an abnormality, the cause of the occurrence of setback is in the left or right part of the front suspension device . If there is no difference between the left and right front wheels of the caster, the inspection method of the wheel alignment according to claim 1, characterized in that evaluating said cause is an suspension system of the rear.

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