JP5882814B2 - Tire wear evaluation method - Google Patents

Description

  The present invention relates to a tire wear evaluation method. In particular, the present invention relates to a method for evaluating wear of a shoulder region of a tread of a tire.

  A wear energy measuring and testing machine is used for tire wear evaluation. In this wear evaluation method, the tire contact pressure and the slip amount are measured. The wear energy is calculated from the product of the contact pressure and the slip amount. Based on this wear energy, tire wear is evaluated.

  The wear evaluation method using the wear energy measuring and testing machine saves time, labor and cost as compared with wear evaluation in an actual vehicle. An example of such a tire wear evaluation method is disclosed in JP-A-11-177410.

JP 11-177410 A

  In this evaluation method, it is necessary to measure the contact pressure and the slip amount in order to obtain the wear energy. It is difficult to simultaneously measure the contact pressure and the slip amount at the same location of the tire. If the contact pressure is measured and the slip amount is measured at different times, multiple measurements are required. In any measurement, in the measurement of the contact pressure, it is necessary to accurately align the position of the measurement point of the tire and the contact pressure sensor.

  The wear situation of the tire varies depending on the use environment of the tire. In general, the center area of a tire is easily worn on a drive wheel. In the driven wheel, the shoulder region is easily worn. Furthermore, the wear situation of the tire differs depending on various conditions such as turning and braking. Even in such different usage environments, tires are required to have an improved wear resistance and a uniform wear progression on the tread surface.

  As one of the evaluations of the uniform wear progress, the shoulder region is evaluated for wear. Also in the wear evaluation of the shoulder region, the wear evaluation is performed based on the wear energy. As described above, in the evaluation based on the wear energy, it is necessary to measure the contact pressure at the measurement point. Accuracy is required to align the position of the tire measurement point with the contact pressure sensor.

  An object of the present invention is to provide a simple method for evaluating wear of a shoulder region of a tire.

  The tire wear evaluation method according to the present invention includes a tire preparation step for preparing a tire, a slip amount acquisition step for obtaining the slip amount of the tire, and a wear evaluation step for evaluating the wear amount from the obtained slip amount. I have. In this slip amount acquisition step, the slip amount of the tire is obtained with at least two different camber angles. In this wear evaluation step, an inclination that is the magnitude of the amount of change of the slip amount with respect to the amount of change of the camber angle is obtained from the slip amount of the two or more different camber angles. When this inclination is equal to or less than a predetermined inclination reference value, the tire wear evaluation is determined to be good.

  Preferably, the inclination reference value is 0.03.

  Preferably, in the wear evaluation step, it is determined that the slip is good when the slip amount is equal to or less than a predetermined slip reference value. Preferably, the slip reference value is determined based on a slip amount of a master tire that has been determined to be good in the market.

  Preferably, the different camber angles are all from -5 ° to 0 °.

  In the evaluation method according to the present invention, wear evaluation is performed based on the slip amount. Even if the contact pressure is not measured, the tire wear can be evaluated.

FIG. 1 is a front view showing a wear tester used in a wear evaluation method according to the present invention. FIG. 2 is a side view seen from the direction of arrow II in FIG. FIG. 3 is an explanatory diagram of the camber angle of the tire in the wear evaluation method according to the present invention. FIG. 4 is an explanatory view showing an image of a tire contact surface obtained by the wear tester of FIG. FIG. 5 is an explanatory diagram of the wear evaluation method according to the present invention. FIG. 6 is a flowchart illustrating an embodiment according to the present invention. FIG. 7 is a flowchart showing another embodiment of the present invention. FIG. 8 is a graph showing the effectiveness of the wear evaluation method according to the present invention. FIG. 9 is another graph showing the effectiveness of the wear evaluation method according to the present invention.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  1 and 2 show a wear energy measurement tester used as the wear tester 2. FIG. The wear test machine 2 includes a control device 4, an information processing device 5, a base 6 and a traveling platform 8. Here, for convenience of explanation, the direction of the arrow X in FIG. 1 is assumed to be forward in the front-rear direction, the direction of the arrow Z is assumed to be upward in the vertical direction, and the direction of the arrow Y in FIG.

  The base 6 includes a road surface 10, a first rail 12, a first ball screw 14, a measuring unit 16, a measuring unit rail 18, and a measuring unit ball screw 20. The base 6 extends in the longitudinal direction in the front-rear direction. The road surface 10 is formed on the upper surface of the base 6. The road surface 10 is a flat surface extending in the front-rear direction. The first rail 12 is located on the left and right of the road surface 10 and extends in the front-rear direction. The first ball screw 14 is located on the side surface of the base 6 and extends in the front-rear direction. The measurement unit 16 is embedded in the road surface 10. The upper surface of the measuring unit 16 is located on the same plane as the road surface 10.

  The measuring unit rail 18 is located below the measuring unit 16. The measuring unit rail 18 extends in the left-right direction. The measuring unit 16 is placed on the measuring unit rail 18. The measuring unit ball screw 20 extends in the left-right direction in parallel with the measuring unit rail 18. The measuring unit 16 includes a nut (not shown). The nut is screwed onto the measuring unit ball screw 20. By rotating the measuring unit ball screw 20, the measuring unit 16 can be moved and positioned in the left-right direction. The measuring unit ball screw 20 is rotated by a servo motor. The position of the measurement unit 16 in the left-right direction is detected by the encoder. The servo motor and the encoder are connected to the control device 4.

  The traveling table 8 includes a frame 22, a second rail 24, a second ball screw 26, a moving table 28, a bearing 30, a rotating device 32, a shaft 34, a third ball screw 36, a support frame 38, a head 40, a drive motor 42, and a swinging motor. A moving ball screw 44 is provided.

  The frame 22 is placed on the first rail 12 of the base 6. The frame 22 is movable in the front-rear direction with respect to the base 6. Although not shown, the frame 22 includes a nut screwed into the first ball screw 14. As the first ball screw 14 rotates, the frame 22 is movable in the front-rear direction. The first ball screw 14 is rotated by a servo motor. The longitudinal position of the frame 22 is detected by the encoder. The servo motor and the encoder are connected to the control device 4.

  The pair of second rails 24 are disposed in front of and behind the upper surface of the frame 22. The second rail 24 extends in the left-right direction. The second ball screw 26 extends in the left-right direction in parallel with the pair of second rails 24. A moving table 28 is placed on the second rail 24. The moving table 28 includes a nut screwed into the second ball screw 26. As the second ball screw 26 rotates, the moving table 28 is movable in the left-right direction. The second ball screw 26 is rotated by a servo motor. The position in the left-right direction of the moving table 28 is detected by the encoder. The servo motor and the encoder are connected to the control device 4.

  The bearing 30 is attached to the movable table 28. The bearing 30 is rotatably attached with its axis as a rotation axis. The rotation device 32 is connected to the outer periphery of the bearing 30. The bearing 30 is rotated with respect to the movable table 28 by the rotation device 32. The rotational position of the bearing 30 is detected by a sensor (not shown). The rotation device 32 and the sensor are connected to the control device 4.

  The shaft 34 is held by the bearing 30. The shaft 34 is movable in the vertical direction with respect to the bearing 30. A third ball screw 36 is connected to the upper end of the shaft 34. As the third ball screw 36 rotates, the shaft 34 is movable in the vertical direction. The third ball screw 36 is rotated by a servo motor. The vertical position of the shaft 34 is detected by the encoder. The servo motor and the encoder are connected to the control device 4.

  The support frame 38 is fixed to the lower end of the shaft 34. The head 40 is swingably attached to the support frame 38. The head 40 is swingable with respect to the support frame 38 with the front-rear direction as a rotation axis. The drive motor 42 is attached to the head 40. One end of the swing ball screw 44 is connected to the head 40. Although not shown, the support frame 38 includes a nut screwed into the swing ball screw 44. As the swing ball screw 44 rotates, the head 40 can swing with respect to the support frame 38. The swing ball screw 44 is rotated by a servo motor. The swing position of the head 40 is detected by the encoder. The servo motor and the encoder are connected to the control device 4.

  Although not shown, the head 40 includes a hub shaft to which a tire is attached. The hub shaft can be switched between a driving rolling state connected to the driving motor 42 and rotating by the driving motor 42 and a free rolling state separated from the driving motor 42 and freely rotatable. . The drive motor 42 is connected to the control device 4. The rotation speed of the drive motor 42 can be controlled.

  Although not shown, the measuring unit 16 includes a camera and a triaxial load cell as a ground pressure sensor. The camera and the three-axis load cell are arranged in the left-right direction. The measuring unit 16 is positioned at a position where the tread surface of the tire contacts the ground. A part of the upper surface of the measuring unit 16 is made of a transparent plate such as a transparent synthetic resin. The camera is arranged so as to be able to photograph the tread surface that contacts the transparent plate. When the tire passes through the upper surface of the measuring unit 16, the triaxial load cell is disposed so as to contact the tire surface. In the wear testing machine 2 of the present invention, the measuring unit 16 may not include a triaxial load cell.

  Although not shown, the information processing apparatus 5 includes a monitor as an output unit, an interface board as a data input unit, a memory, a CPU, and a hard disk. The information processing apparatus 5 may include a keyboard and a mouse. A general-purpose computer may be used as the information processing apparatus 5 as it is.

  The hard disk stores a program. The memory is rewritable, and constitutes a storage area and a work area for programs called from the hard disk and various data. The CPU can read a program stored in the hard disk. The CPU can expand the program in the work area of the memory. The CPU can execute various processes according to the program.

  A signal can be input from the control device 4 to the interface board. A signal obtained by the control device 4 can be input to the interface board. The CPU of the information processing device 5 calculates predetermined data from the input signal. These data are output to the monitor. These data are stored in the hard disk.

  A one-dot chain line VL in FIG. 3 indicates a vertical line. A two-dot chain line CL indicates the equator plane of the tire. A double arrow γ is an angle formed by the vertical line VL and the equator plane CL. This angle γ represents the camber angle. With respect to the vertical line VL, the camber angle γ is expressed with a negative direction from the outside of the vehicle body toward the inside from the bottom to the top and a negative direction from the inside to the outside of the vehicle body as a positive. In the wear tester 2, the direction inclined toward the head 40 from the lower side to the upper side is expressed as negative. The camber angle γ is given by the head 40 being swung with respect to the support frame 38.

  FIG. 4 shows an image obtained by photographing the tread surface that contacts the transparent plate of the measurement unit 16. Point P and point Q in FIG. 4 indicate slip amount measurement points. In FIG. 4, the measurement point P and the measurement point Q are located at the axial end of the ground contact surface. This axial end is an end on the axially outer side of the shoulder region. This shoulder region is a shoulder region located on the side pressed against the road surface 10 when the camber angle γ is applied and tilted. The measurement point P is located at the first end of the block B divided by the groove G. The measurement point Q is located at the rear end of the block B.

  A point P0 in FIG. 5 indicates the position of the theoretical measurement point P on the image in FIG. This point P0 is obtained by calculation from the position of the measurement point P when the traveling platform 8 is at the original position, for example. Point P1 indicates the position of the actual measurement point P photographed by the camera. A double-headed arrow dx indicates the distance between the point P0 and the point P1 in the X-axis direction. This distance dx is the slip amount in the X-axis direction. Similarly, the double arrow dy indicates the distance between the point P0 and the point P1 in the Y-axis direction, and the distance dy is the slip amount in the Y-axis direction.

  FIG. 6 shows a flowchart of the tire wear evaluation method according to the present invention. The wear evaluation method according to the present invention will be described using the wear tester 2 illustrated in FIGS. 1 and 2.

  A tire is prepared for wear evaluation. This is a tire preparation step (STEP 10). Next, the process proceeds from the tire preparation step (STEP 10) to the slip amount acquisition step (STEP 20). The slip amount acquiring step (STEP 20) includes a mark sticking step (STEP 21), a tire mounting step (STEP 22), a test condition setting step (STEP 23), a slip amount measuring step (STEP 24), and a total camber angle measurement determining step (STEP 25). ing.

  A mark is affixed to the tire. This is a mark sticking step (STEP 21). As shown in FIG. 4, marks are attached to measurement points P and Q on the tread surface. For example, the tread surface is masked with a template in which holes are formed at the positions of the measurement points P and Q. With this mask on, the paint is sprayed to attach the mark. This tire is attached to the wear tester 2. This is a tire attachment step (STEP 22). This tire is attached to the hub shaft of the head 40.

  Test conditions are input to the control device 4 of the wear tester 2. This is a test condition setting step (STEP 23). As test conditions, travel speed, load, and the like are input. These test conditions may be input from the information processing device 5 to the control device 4. At this time, the test conditions may be input to the information processing apparatus 5 in advance, or may be input to the information processing apparatus 5 each time. In this test condition setting step (STEP 23), at least two or more camber angles γ, for example, camber angles γ1 and γ2 are input as test conditions.

  Based on the input test conditions, the amount of slip is measured. This is a slip amount measuring step (STEP 24). This tire is supported by the head 40 in a free rolling state. The tire is grounded on the road surface 10. A camber angle γ1 is given to the tire. The tire is pressed against the road surface 10 with a predetermined load. The traveling platform 8 travels forward.

  The tread surface of the tire passing through the upper surface of the measuring unit 16 is photographed by the camera. This photographing signal is transmitted to the control device 4. The control device 4 measures the positions of the measurement point P and the measurement point Q from this photographing signal. At this measurement point P and measurement point Q, the respective slip amounts are measured.

  Next, it is determined whether the slip amount has been measured for all the camber angles γ given under the test conditions. This is a total camber angle measurement determination step (STEP 25). Here, since the camber angle γ2 has not been measured, the process returns to the slip amount measurement step (STEP 24). In the slip amount measuring step (STEP 24), the slip amount at the camber angle γ2 is measured. Furthermore, when other camber angles are given, the slip amount measuring step (STEP 24) and the measurement completion determining step (STEP 25) are repeated until the slip amount is measured for all the camber angles γ. Slip amounts dx and dy at each camber angle γ are transmitted from the control device 4 to the information processing device 5. When the slip amount is measured for all the camber angles γ, the slip amount acquisition step (STEP 20) is completed.

  When the slip amount acquisition step (STEP 20) is completed, the process proceeds to the wear evaluation step (STEP 30). The wear evaluation step (STEP) 30 includes an inclination calculation step (STEP 31) and an inclination determination step (STEP 32).

  In the information processing apparatus 5, the inclination Ax in the X-axis direction and the inclination Ay in the Y-axis direction are calculated from the camber angle γ and the slip amount. This is an inclination calculation step (STEP 31). Here, the inclination in the front-rear direction (X-axis direction) and the inclination in the left-right direction (Y-axis direction) are obtained separately.

  An average slip amount dxa is calculated from the slip amount dx at the measurement point P and the slip amount dx at the measurement point Q. A slip slope Ax in the X-axis direction is obtained from a plurality of camber angles γ of 2 or more and an average slip amount dxa at each. Specifically, the inclination Ax is obtained as a change amount of the slip amount dxa when the camber angle γ changes by 1 °.

For example, when the horizontal axis is the camber angle and the vertical axis is the slip amount dxa, the following first-order approximation is obtained by the least square method.
dxa = Ax · γ + S
From this approximate expression, the slope Ax is obtained.

  Similar to the inclination Ax, the inclination Ay in the Y-axis direction is obtained. The average slip amount dya is calculated from the slip amount dy at the measurement point P and the slip amount dy at the measurement point Q. From the average slip amount dya and the camber angle γ, the change amount of the slip amount dya when the camber angle γ changes by 1 ° is obtained. This change amount is the slope Ay.

  The information processing apparatus 5 makes a pass / fail determination based on the inclination A (Ax and Ay). The information processing device 5 makes a good (pass) determination or a bad (fail) determination. This is an inclination determination step (STEP 32). For example, the information processing device 5 is given a slope reference value for pass / fail determination in advance. Here, it is determined whether each of the inclination Ax and the inclination Ay is equal to or less than a reference value. When the slopes Ax and Ay are equal to or less than the reference value, the tire is judged good. When the slope Ax or the slope Ay exceeds the reference value, the tire is determined to be defective. When the slope Ax or the slope Ay exceeds the reference value, the tire is determined to be defective. This evaluation method ends when the tire is determined to pass or fail.

  FIG. 7 shows a flowchart of a tire wear evaluation method according to another embodiment of the present invention. Here, a configuration different from the evaluation method shown in FIG. 6 will be described.

In this evaluation method, the wear evaluation step (STEP 30) includes an inclination calculation step (STEP 31), an inclination determination step (STEP 32), and a slip amount determination step (STEP 33).
In the same manner as in the evaluation method of FIG. 6, a pass / fail determination is made in the inclination determination step (STEP 32). Here, if a failure is determined, this evaluation method is completed. If it is determined to be good, the process proceeds to a slip amount determination step (STEP 33).

  In the slip amount determination step (STEP 33), the information processing apparatus 5 makes a pass / fail determination based on the slip amounts dx and dy. For example, the information processing device 5 is previously given a reference value for the slip amount for the pass / fail determination. For example, the tire may be determined based on a tire whose wear in the shoulder region is well determined in a certain market use environment. Specifically, a tire having a track record in which no wear failure has occurred in a predetermined period of use in a certain market environment is prepared as a master tire. The reference value may be determined based on the slip amount of the master tire.

  Here, it is determined whether or not each of the slip amount dxa and the slip amount dya is equal to or less than a reference value. When the slip amount dxa and the slip amount dya are equal to or less than the reference value, the tire is judged good. When the slip amount dxa and the slip amount dya exceed the reference value, the tire is determined to be defective. When the slip amount dxa or the slip amount dya exceeds the reference value, the tire is determined to be defective. This evaluation method ends when the tire is determined to pass or fail.

  FIG. 8A shows the wear energy of the test tire S1 and the test tire S2. The tire S1 is a tire with a large shoulder wear. The tire S2 is a tire with small shoulder wear. The relationship between the camber angle and the wear energy is shown for the tire S1 and the tire S2. When the camber angle γ is 0 °, the wear energy between the tire S1 and the tire S2 does not change significantly. When the camber angle γ is −5 °, the wear energy of the tire S1 is greatly increased as compared with the wear energy of the tire S2.

  FIG. 8B shows the relationship between the camber angle and the slip amount among the relationship between the wear energy and the camber angle in FIG. FIG. 8C shows the relationship between the camber angle and the contact pressure. As shown in FIG. 8C, even when the camber angle γ is changed, the contact pressure of the tire S1 and the contact pressure of the tire S2 are not significantly changed. As shown in FIG. 8B, when the camber angle changes, the slip amount of the tire S1 greatly increases compared to the slip amount of the tire S2. In the tire S2, it can be seen that the increase in slip amount contributes greatly to the increase in wear energy due to the change in camber angle.

  FIG. 9A further shows the relationship between the camber angle and the slip amount for the test tires S3 to S7. FIG. 9B shows the relationship between the camber angle and the contact pressure for the test tires S3 to S7. As shown in FIG. 9 (b), the contact pressure does not change greatly even for the tire S3 to the test tire S7 even if the camber angle γ changes. As shown in FIG. 9A, in the tire S6 and the tire S7, even if the camber angle γ changes, the slip amount does not change greatly. On the other hand, in the tires S3 to S5, when the camber angle γ changes, the slip amount greatly changes.

  From the test results of the test tires S1 to S7, it can be seen that the increase in the slip amount greatly contributes to the increase in the wear energy due to the change in the camber angle. The wear evaluation method according to the present invention evaluates wear based on the relationship between an increase in wear energy due to a change in camber angle and an increase in slip amount. From the test results of the test tires S1 to S2, the effectiveness of this wear evaluation method is clear.

  According to this wear evaluation method, wear evaluation can be performed from the slip amount of the measurement points P and Q of the tire. In this wear evaluation method, it is not necessary to measure the contact pressure. The trouble of matching the positional relationship between the sensor for measuring the contact pressure and the measurement points P and Q with high accuracy is saved. If the positions of the actual measurement points P and Q photographed by the camera and the respective theoretical positions are specified, the wear evaluation can be performed. The present invention can evaluate the wear of the shoulder region by a simple method.

  Furthermore, since the wear evaluation method shown in FIG. 7 includes a slip amount determination step (STEP 33), wear evaluation is performed based on the amount of slip. Thereby, a tire with a large absolute value of a slip amount and a tire with a small slip can be more reliably determined. If the slip amount reference value is determined based on the slip amount of the master tire, a pass / fail determination can be made in the usage environment of the market where the master work is determined to be good.

  Here, the slip amount at two points of the measurement point P and the measurement point G is obtained, and the determination is made based on the slip amount of the average value. By using the average value of the two points, the influence of the positions on the first arrival side and the rear arrival side is offset. By using the average value of these two points, the influence due to the rotation direction of the tire is offset. In this evaluation method, any one of the measurement point P and the measurement point Q may be used as the slip amount measurement point. Further, measurement points other than the measurement point P and the measurement point Q may be used.

  The measurement point P and the measurement point Q are provided at an end portion on the outer side in the axial direction of the shoulder region, which is located on the side pressed against the road surface 10 when the camber angle γ is given. At this end, the amount of slip appears remarkably. Further, the slip amount appears most noticeably at the first and second end portions of the block B divided by the groove G. By measuring at the measurement point P and the measurement point Q, it is easier to determine whether or not the shoulder region wears.

  The slip amount dx in the front-rear direction greatly contributes to the size of the tire radius, the shape of the tread surface in the axial direction, and the like. The slip amount dy in the left-right direction greatly contributes to tire deflection. Depending on the tread stiffness and side stiffness, the amount of tire deflection changes. In this evaluation method, since the slip amount dx in the front-rear direction and the slip amount dy in the left-right direction are obtained separately, the direction of improvement in tire wear reduction can be shown from the result of tire wear evaluation.

  Here, wear evaluation was performed using the slip amount dx and the slip amount dy, but instead of the slip amount dx and the slip amount dy, a combined slip amount (the square of the slip amount dx) with the slip amount dx and the slip amount dy. And the square root of the sum of the squares of the slip amount dy) may be used.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

  A master tire for shoulder region wear evaluation was prepared. This master tire has been confirmed to have good wear evaluation in the shoulder region in the market. About this master tire, as shown in FIG. 4, the measurement point P and the measurement point Q were determined, and the slip amount was measured. The camber angle γ at this time is 0 ° to −5 °. Table 1 shows measured values of the average value dxa of the slip amount in the front-rear direction and the average value dya of the slip amount in the left-right direction.

  Tires A to F were prepared as test tires. The wear evaluation according to the present invention shown in FIG. 7 was performed on the master tire and tires A to F described above.

  In this evaluation method, the inclination Ax and the inclination Ay were determined in the inclination determination step (STEP 32). The reference values were all 0.03.

  In the slip amount determination step (STEP 33), the slip amount of each camber angle was determined. For each camber angle, the ratio of the slip amount when the slip amount of the master work was set to 1 was obtained. The average value of the ratio of the slip amount of each camber angle was determined to be 1.5 or less as good.

  Table 2 shows the ratio of the slip amount in the front-rear direction of each camber angle γ of the tires A to F and the inclination Ax. Table 3 shows the ratio of the slip amount in the left-right direction of each camber angle of the tires A to F and the inclination Ax.

  In this evaluation method, tires A, B, and C were determined to be defective. Tires D, E, and F were judged good. This determination result was consistent with the conventional evaluation result based on wear energy. Also from this evaluation result, it is clear that the wear evaluation of the shoulder region of the tire is made effective by the evaluation method of the present invention.

DESCRIPTION OF SYMBOLS 2 ... Wear test machine 4 ... Control apparatus 5 ... Information processing apparatus 6 ... Base 8 ... Running stand 10 ... Road surface 12 ... First rail 14 ... First ball screw DESCRIPTION OF SYMBOLS 16 ... Measuring part 18 ... Measuring part rail 20 ... Measuring part ball screw 22 ... Frame 24 ... Second rail 26 ... Second ball screw 28 ... Moving stand 30 ... Bearing 32 ... Rotating device 34 ... Shaft 36 ... Third ball screw 38 ... Support frame 40 ... Head 42 ... Drive motor 44 ... Oscillating ball screw

Claims (5)

A tire preparation process for preparing a tire;
A slip amount acquisition step for acquiring the slip amount of the tire;
And a wear evaluation step for evaluating the wear amount from the obtained slip amount,
In this slip amount acquisition step, the slip amount of the tire is obtained with at least two different camber angles,
In this wear evaluation process, the slope which is the magnitude of the change amount of the slip amount with respect to the change amount of the camber angle is obtained from the slip amount of the two or more different camber angles.
A tire wear evaluation method in which the wear evaluation is determined to be good when the slope is equal to or less than a predetermined slope reference value.   The wear evaluation method according to claim 1, wherein the inclination reference value is 0.03.   The wear evaluation method according to claim 1 or 2, wherein in the wear evaluation step, a good determination is made when the slip amount is equal to or less than a predetermined slip reference value.   The wear evaluation method according to claim 3, wherein the slip reference value is determined based on a slip amount of a master tire that has been well determined in the market.   The wear evaluation method according to any one of claims 1 to 4, wherein each of the different camber angles is -5 ° or more and 0 ° or less.

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