JP2002116119A - Grounding part measuring device for tire tread and grounding part measuring method of tire tread - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grounding part measuring device for tire tread capable of highly accurately and automatically measuring force and a slding quantity acting on measuring points. SOLUTION: Position coordinates of the whole measuring points (marks) of a tire are read and stored by a coordinate measuring camera of a road surface 92 with built-in measuring instrument. A control means automatically adjusts at least one of a start position of a test tire 82 and a position of a force sensor on the basis of the stored position coordinates so that the measuring points abut to the force sensor of the road surface 92 with built-in measuring instrument. Afterwards, when the test tire 82 is rolled and passed through onto the force sensor, the measuring points of the tire tread abut to the force sensor, and the magnitude of force is measured along the road surface. Since at least one of the start position of the test tire 82 and the position of the force sensor is automatically adjusted on the respective measuring points, even if there are a large number of measuring points, precise measurement can be performed without taking labor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring a contact area of a tire tread and a tire tread for measuring at least the amount of slip of the tire tread on a road surface and the magnitude of a force along the road surface during rolling of the tire. In particular, the present invention relates to a ground contact measuring device and a tire tread surface measuring method capable of efficiently measuring a large number of measurement points.

[0002]

2. Description of the Related Art The distribution of abrasion of a tread substantially corresponds to the distribution of abrasion work, and the abrasion work is determined by the product of the amount of slip and the stress on a tread in a ground contact surface.

As a device for obtaining the work of wear by the product of the amount of slip and the stress, for example, there is a device for measuring the contact portion of a tire tread described in JP-A-7-63658.

The device for measuring a tread on a tread of a tire includes a television camera for photographing a displacement of the tread and a three-component sensor (three-component transducer) for measuring a force in three directions acting on a tread of the tire. Is what it is.

[0005] Then, a calculation is performed based on the measured values (force and slip amount) obtained by the device for measuring the contact portion of the tire tread to obtain the work of wear.

[0006]

(1) In the conventional device for measuring the contact area of the tread of a tire, a mark (round point) is formed on a measurement point in the tread with a white pen, and the mark and the three-component force sensor make good contact. In this case, the measurer adjusts the rolling start position of the tire by pressing the positioning button on the operation panel.

However, these operations require skill and patience, and it is difficult to cope with many measurement points, input conditions, and many tires. (2) Conventionally, as shown in FIG. 13, a mark 202 smaller than the size of the contact portion 200 of the three-component sensor is marked on the tread 204.

The contact part 2 between the mark 202 and the three-component sensor
The accuracy of the position where 00 contacts is greatly affected by the measurement result. However, when the mark 202 on the tread and the contact portion 200 of the three-component sensor overlap, the mark 202 is hidden by the three-component sensor, so that the mark 202 is hidden. The deviation amount (Δx, Δy) between the sensor and the three-component force sensor cannot be determined, and it is difficult to control the accuracy. That is, the accuracy with which the mark 202 is applied to the center of the contact portion 200 of the three-component sensor depends on human factors, and it has been difficult to improve the measurement accuracy. (3) In the conventional mark method using a white pen, since a commercially available writing instrument such as a felt-tip pen or a ball-point pen is used, the area and shape of the mark 202 are uneven, and the measurement result tends to vary.

If the area and the shape of the mark 202 hit at the measurement point vary, the center position of the mark 202 becomes unclear and it is difficult to match the center position of the three-component sensor.

In view of the above facts, the present invention provides a tire tread contact surface measuring device and a tread surface contact measuring method capable of automatically and automatically measuring the force and the amount of slip applied to a measuring point. The purpose is to provide.

[0011]

According to the first aspect of the present invention, a test tire is rolled on a road surface, and at least a road surface acting on the measurement point when the measurement point in the tire tread contacts the road surface. A tire ground contact measuring device for detecting the magnitude of the force along the direction using a force sensor, and detecting the amount of slip of the measurement point with respect to the road surface using a reading sensor, comprising a plurality of measurement points. When sequentially detecting the magnitude of the force and the amount of slip for each of the positions, the position coordinates of all the measurement points are read and stored in advance, and the start position and the start position of the test tire are set based on the read position coordinates. Control means for automatically adjusting at least one of the positions of the force sensor is provided, and when the magnitude of the force and the amount of slip are detected for each of the measurement points, the measurement point comes into contact with the force sensor As described above, the control means automatically adjusts at least one of the start position of the test tire and the position of the force sensor, and thereafter, the magnitude of the force acting on the measurement point by rolling the test tire on a road surface. It is characterized in that the slip amount is detected.

Next, the operation of the tire ground contact measuring device according to the first aspect will be described.

When the test tire is rolled on a road surface and passed over a force sensor in the device for measuring a contact portion of a tire, when the tire tread touches the road surface, at least the magnitude of the force along the road surface is measured. It can be measured with a sensor.

Further, the reading sensor can measure the amount of slip of the measurement point with respect to the road surface.

In the measurement procedure, first, the control means reads and stores the position coordinates of all the measurement points.

Next, the control means automatically adjusts at least one of the start position of the test tire and the position of the force sensor based on the stored position coordinates so that the measurement point comes into contact with the force sensor.

Then, the test tire is rolled on the road surface,
When the tire passes over the force sensor, the measurement point on the tire tread contacts the force sensor, and the magnitude of the force along the road surface is measured.

At least one of the start position of the test tire and the position of the force sensor is automatically adjusted for each of the measurement points, so that even if there are a large number of measurement points, accurate measurement can be performed without any trouble. .

According to a second aspect of the present invention, in the device for measuring a tread of a tire tread according to the first aspect, a relative distance between the measuring point and the force sensor when the measuring point contacts the force sensor. If is larger than a predetermined reference size, at least one of the start position of the test tire and the position of the force sensor is automatically adjusted again, and then the measurement is performed again.

Next, the operation of the tire ground contact measuring device according to the second aspect will be described.

In the tire contact measuring device according to the second aspect, the relative distance between the measurement point and the force sensor at the time of contact with the force sensor is detected by the position adjusting means. When the relative distance is larger than a predetermined reference dimension, at least one of the start position of the test tire and the position of the force sensor is automatically adjusted again, and the measurement is performed again. Thus, the force sensor and the measurement point can always be made to coincide with each other, so that more accurate measurement can be performed.

According to a third aspect of the present invention, when a test tire is rolled on a road surface and a measurement point in the tire tread is in contact with the road surface, a force acting on the measurement point at least in a direction along the road surface surface. A method for measuring the tire ground contact portion, wherein the magnitude of the tire is detected using a force sensor, and the slip amount of the measurement point with respect to the road surface is detected using a reading sensor.
When sequentially detecting the magnitude of the force and the amount of slip for each of the plurality of measurement points, the position coordinates of all the measurement points are stored in advance, and the magnitude of the force and the magnitude of the force are measured for each of the measurement points. When detecting the amount of slip, after automatically adjusting at least one of a start position of the test tire and a position of the force sensor so that the measurement point contacts the force sensor, the test tire is It is characterized by detecting the magnitude of the force acting on the measurement point and the slip amount by rolling on a road surface.

Next, the operation of the method for measuring a contact portion of a tire according to the third aspect will be described.

When the test tire is rolled on a road surface and passes over a force sensor, the magnitude of the force at least along the road surface when the tire tread touches the road surface is measured by the force sensor.

The reading sensor measures the slip amount of the measurement point with respect to the road surface.

In the measurement procedure, first, the control means reads and stores the position coordinates of all the measurement points.

Next, the control means automatically adjusts at least one of the start position of the test tire and the position of the force sensor based on the stored position coordinates so that the measurement point comes into contact with the force sensor.

Then, the test tire is rolled on the road surface,
When the tire passes over the force sensor, the measurement point on the tire tread contacts the force sensor, and the magnitude of the force along the road surface is measured.

Since at least one of the starting position of the test tire and the position of the force sensor is automatically adjusted for each of the measuring points, accurate measurement can be performed without much trouble even if there are many measuring points. .

According to a fourth aspect of the present invention, in the method for measuring a contact portion of a tire tread according to the third aspect, a relative distance between the measuring point and the force sensor when the measuring point contacts the force sensor. Is larger than a predetermined reference size, the control means automatically adjusts at least one of the start position of the test tire and the position of the force sensor again, and then performs re-measurement.

Next, the operation of the method for measuring a contact portion of a tire according to the fourth aspect will be described.

According to the fourth aspect of the present invention, the relative distance between the measurement point at the time of contact with the force sensor and the force sensor is detected by the position adjusting means. When the relative distance is larger than a predetermined reference dimension, at least one of the start position of the test tire and the position of the force sensor is automatically adjusted again, and the measurement is performed again. Thus, the force sensor and the measurement point can always be made to coincide with each other, so that more accurate measurement can be performed.

According to a fifth aspect of the present invention, in the method for measuring a tread surface of a tire tread according to the third or fourth aspect, a mark readable by the reading sensor is added to the measurement point using a template. It is characterized by doing.

Next, the operation of the method for measuring a contact portion of a tire according to the fifth aspect will be described.

According to the fifth aspect of the present invention, since a mark that can be read by a reading sensor is provided to a measurement point using a template, a highly accurate mark having a uniform shape can be accurately applied to the measurement point. And it can be given with high precision. Therefore, the position of the measurement point can be accurately read by the reading sensor.

According to a sixth aspect of the present invention, in the method of the fifth aspect, the shape and size of the mark are the same as the shape and size of a portion where the force sensor contacts the tread. It is characterized by being.

Next, the operation of the method for measuring a contact portion of a tire according to the sixth aspect will be described.

In the method for measuring a contact portion of a tire according to the sixth aspect, the shape and size of the mark are the same as the shape and size of the portion where the force sensor contacts the tread surface. In the case where the position of the portion contacting the camera is shifted, the shift amount and the shift direction can be accurately and accurately detected by image processing.

If the shape of the mark is the same as the portion where the force sensor contacts the tread, the size of the mark may be larger than the shape of the portion where the force sensor contacts the tread.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the apparatus for measuring a tread of a tire tread according to the present invention will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the grounding section measuring device 10 includes a long base frame 12.

As shown in FIGS. 1 to 3, on both sides of the base frame 12 in the width direction (the direction of the arrow F and the direction of the arrow B), along the longitudinal direction of the base frame 12 (the direction of the arrow L and the direction of the arrow R). A slide rail 14 extending is attached, and a road surface 16 extending in the longitudinal direction is provided at a substantially middle portion in the width direction.

A tire traveling device 20 is slidably mounted on the slide rail 14 via a linear motion guide 18.

On a side surface of the base frame 12, a ball screw 24 rotated by a servo motor 22 is supported by a bearing 26.

A nut 30 to which a ball screw 24 is screwed is fixed to a frame 28 of the tire traveling device 20. By rotating the ball screw 24, the tire traveling device 20 can be moved along the slide rail 14. it can.

The frame-like frame 28 is provided with an encoder 21 (see FIG. 6) for detecting the position of the tire traveling device 20. As shown in FIG. 6, the servo motor 22 and the encoder 21 are connected to a control device 23 including a computer.

A slide rail 32 extending along a direction perpendicular to the longitudinal direction of the base frame 12 is attached to the upper part of the frame-shaped frame 28, and the slide rail 32 is connected to the slide rail 32 via a linear motion guide 34. A movable base 36 is slidably mounted.

A ball screw 40 rotated by a servomotor 38 is supported by a bearing 42 on the upper portion of the frame 28.

A nut (not shown) with which the ball screw 40 is screwed is fixed to the moving base 36, and the moving base 36 can be moved along the slide rail 32 by rotating the ball screw 40.

The frame-like frame 28 is provided with an encoder 43 (see FIG. 6) for detecting the position of the moving base 36, and the servomotor 38 and the encoder 43 are connected to the controller 23.

A frame-like frame 46 is rotatably provided at the upper center of the movable base 36 via a thrust bearing 44.

At the center of the frame 46, a bearing 48 is mounted.

A shaft 50 is slidably supported by the bearing 48 in the vertical direction.

A screw jack 51 for changing a slip angle, which is driven by a servo motor 49, is mounted on the upper part of the moving base 36.
Pin 56 provided on the bearing 54 at the tip of the screw 52
Is inserted into a hole (not shown) at the distal end of a lever 58 protruding outside the bearing 42.

Therefore, by moving the screw 52 in the axial direction, the shaft 5 supported by the bearing 42 is moved.
0 is rotatable within a certain range with respect to the moving base 36.

On the upper part of the frame 46, a servo motor 6
A screw jack 64 for loading a load powered by 2 is attached, and a screw 66 of the screw jack 64 is connected to the shaft 50.

Therefore, by moving the screw 66 in the axial direction, the shaft 5 supported by the bearing 42 is moved.
0 moves up and down.

The moving base 36 is provided with a rotary encoder 61 (see FIG. 6) for detecting the angle (slip angle) of the bearing 42 (shaft 50) and an encoder 63 for detecting the vertical position of the shaft 50. The motor 49, the rotary encoder 61, the servomotor 62, and the encoder 63 are connected to the control device 23.

At the lower end of the shaft 50, a T-shaped horizontal rotating frame 68 is attached so as to be suspended.

The horizontal rotating frame 68 has a horizontal portion 68A extending in the horizontal direction and a vertical portion 68B extending downward from the center of the horizontal portion 68A, and the shaft 50 is fixed to one end of the horizontal portion 68A.

At the lower end of the vertical portion 68B of the horizontal rotating frame 68, a shaft 70 is mounted horizontally.

The shaft 70 has a tire support frame 7
2 is swingably supported.

A screw jack 74 for changing the camber angle, which is driven by a servo motor 73, is attached to a horizontal portion 68 A of the horizontal rotating frame 68. A bearing 78 at the tip of a screw 76 of the screw jack 74.
Are inserted into holes (not shown) of the tire support frame 72.

Therefore, by moving the screw 76 in the axial direction, the tire support frame 72 swings about the shaft 70.

The horizontal rotation frame 68 is provided with a rotary encoder 81 (see FIG. 6) for detecting the angle (camber angle) of the tire support frame 72. The servo motor 73 and the rotary encoder 81 are connected to the control device 23.

The tire support frame 72 is provided with a hub shaft 84 on which the test tire 82 is mounted, a braking / driving servomotor 86 for rotating the hub shaft 84, and a rotary encoder 87 for detecting the rotational position of the hub shaft 84. .

The hub axle 84 has a load cell 89 for detecting a force (load or the like) acting on the test tire 82.
(See FIG. 6).

The braking / driving servomotor 86, rotary encoder 87, and load cell 89 are connected to the controller 23.

A part of the road surface 16 has a recess 8
8 are provided. A slide rail 90 extending along a direction perpendicular to the longitudinal direction of the road surface 16 is attached to the bottom surface of the concave portion 88.
, A measuring instrument built-in road surface 92 is slidably mounted via a linear motion guide 91.

A ball screw 97 rotated by a servomotor 95 is supported by a bearing 99 on the bottom surface of the concave portion 88.

A nut (not shown) with which a ball screw 97 is screwed is fixed to the measuring instrument built-in road surface 92. By rotating the ball screw 97, the measuring instrument built-in road surface 92 is orthogonal to the longitudinal direction of the road surface 16. Can be moved in any direction.

The road surface 16 is provided with an encoder 93 (see FIG. 6) for detecting the position of the measuring device built-in road surface 92, and the encoder 93 is connected to the control device 23.

A slip measuring section 94 is provided on the road surface 92 with a built-in measuring instrument.
And a coordinate measuring unit 96 are provided.

The slip measuring section 94 has a transparent road surface plate 98 made of a transparent synthetic resin (acrylic or the like).

The measuring instrument built-in road surface 92 has a concave portion 100 below the transparent road surface plate 98.

The transparent road surface plate 98 can measure the magnitude of the force in each of three directions (longitudinal direction of the road surface 16, width direction of the road surface 16, and vertical direction of the road surface 16) received from the tread surface of the test tire 82 for three minutes. A force sensor 102 is attached, and a contact portion (upper end) 102 </ b> A of the three-component force sensor 102 protrudes from a hole 104 of the transparent road surface plate 98. Note that the shape of the contact portion 102A is circular.

A turtle (CCD camera) 10 for displacement measurement is provided on the concave portion 100 on both sides of the three-component force sensor 102 in the road surface width direction.
6 is arranged toward the hole 104, and a slip measurement camera (CCD camera) 108 is arranged upward in the direction of the arrow L.

The concave portion 100 has a light source 11 for photographing.
0 is provided upward.

On the other hand, the coordinate measuring section 96 includes a transparent road surface plate 112 made of a transparent synthetic resin (such as acrylic).

A coordinate measuring camera (CCD camera) 116 and a light source 118 are arranged upward in a concave portion 114 provided below the transparent road surface plate 112.

The three-component sensor 102, the displacement measuring camera 106, the slip measuring camera 108, and the coordinate measuring camera 116 are connected to the control device 23.

The control device 23 is connected with a television monitor 120, a keyboard 122 for performing various settings, a storage device 124, and the like. (Operation) Next, the operation of the grounding section measuring device 10 of the present embodiment will be described with reference to the flowchart of FIG.

As shown in FIG. 7, first, at step 100
Then, marks are given to all measurement points on the tread of the test tire 82 using a template 130 as shown in FIG.

The template 130 has a plurality of round holes 132 corresponding to the measurement points. The template 130 is attached to a tread, and a white paint (at least a color other than the tire color) is applied from above the template 130. Is sprayed with a spray gun or the like, and the template 130 is peeled off.

As a result, as shown in FIG. 9, a circular mark 134 of the same size, which is not deformed, is accurately marked at each measurement point of the tread.

This mark 134 indicates that the three-component sensor 10
It is a circle of the same size as the second contact portion 102A.

If the mark 134 has a thickness, a measurement error of the three-component sensor 102 occurs, so that the mark 13
Preferably, the thickness of 4 is as thin as possible.

As the paint, a paint spray (white) for Asahi leather shoes having a thin coating film after drying is preferable.

In step 102, the test tire 82 is mounted on the hub axle 84. At this time, the tire traveling device 20 is located at the start position of the tire traveling device 20 (the position on the arrow L direction side as shown in FIG. 1).
Shaft 50 is in the raised position.

In step 104, test conditions are set. The test conditions include slip angle (SA), camber angle (CA), load, braking force, driving force, etc.
Each can be set multiple times. These values are stored on the keyboard 122
More input.

By adjusting the moving speed of the tire traveling device 20 and the rotation speed of the braking / driving servomotor 86, the braking / driving force can be applied to the test tire 82 traveling on the road surface 16.

In step 106, the coordinate measuring camera 1
16 are arranged below the running trajectory of the test tire 82, and the slip angle (SA), camber angle (CA), load, braking / driving force, etc. determined under the initial test conditions are determined by the test tire 82.
The tire traveling device 20 is moved in the direction of arrow R in a state where the test tire 82 is in contact with the road surface 16, and the marks 134 of all measurement points are photographed by the coordinate measuring camera 116.

Then, based on the data of the photographed image (see FIG. 9), the control device 23 coordinates the positions of all the marks 134 (the position (X axis) in the tire width direction from a certain reference position of the device and the tire). Position in the circumferential direction (Y axis))
The rotational position of the test tire 82 at the time of photographing the mark is stored.

The mark 134 has a circular shape.
Since the shapes are all uniform, the position of the mark 134 can be accurately coordinated.

In step 108, the start position for measuring the three-component force is determined. Specifically, based on the diameter of the test tire 82, the coordinates of the mark 134, and the rotational position of the test tire 82 which are input in advance, the first mark 134 to be measured first is in contact with the contact portion 102A of the three-component sensor 102. The start position (rotation position) of the test tire 82 and the arrangement position of the three-component sensor 102 (and / or the arrangement position of the moving base 36) are calculated so as to match.

Then, the tire traveling device 20 is moved in the reverse direction (the direction of the arrow L) to stop the tire traveling device 20 at the start position, and at the same time, the test tire 82 is raised and separated from the road surface 16 once to obtain the calculated value. The test tire 82 is stopped at the start position (rotation position) for the three-component force measurement (positioning of the mark 134), and the three-component force sensor is moved to the position obtained by calculation by moving the measuring instrument built-in road surface 92. Position 102 (and / or position moving base 36).

In step 110, the test tire 82 is again brought into contact with the road surface 16, and the tire traveling device 20 is moved in the direction of arrow R. Thereby, the test tire 82 rolls on the road surface 16 and the road surface 92 with the built-in measuring instrument.

When the test tire 82 passes through the road surface 92 with a built-in measuring instrument, the camera 106 for measuring the displacement is used until at least the mark 134 contacts and separates from the three-component sensor 102 and the treads of the tire treads before and after it. Take a picture.

Further, the tread of the test tire 82 comes into contact with the contact portion 102A of the three-component sensor 102, and the three-component sensor 102 measures the magnitude of the force acting on the measurement point in three directions. Then, the control device 23 controls the shift measuring camera 1
In addition, the coordinates of the mark 134 are stored based on the data transmitted from the sensor 06, and the magnitudes of the forces in the three directions are stored with time based on the data transmitted from the three-component sensor 102 (see FIG. 11). Fx represents the force in the width direction of the road surface, Fy represents the force in the longitudinal direction of the road surface, and Fz represents the force in the vertical direction of the road surface.)

In step 112, the camera 1 for measuring the displacement
Mark 134 obtained from the data sent from 06
From the coordinates of the contact portion 102A and the coordinates of
Mark 1 for contact portion 102A of component force sensor 102
The shift amounts (.DELTA.x and .DELTA.y in FIG. 10) are calculated, and it is determined whether or not the shift amounts are within a predetermined reference. In the present embodiment, the shape and size of the mark 134 are the same as the shape and size of the contact portion 102A of the three-component sensor 102. Therefore, when the position of the mark 134 and the position of the The amount and the direction of displacement can be accurately and accurately detected by image processing.

Here, when it is determined that the value is within the standard, the process proceeds to step 114, and when it is determined that the value is not within the standard, the process proceeds to step 116.

In step 116, the start position of the test tire 82 and the arrangement position of the three-component sensor 102 (and / or the arrangement position of the moving base 36) are recalculated so as to make the above-mentioned displacement amount zero.

In step 114, a start position for slip measurement is determined.

More specifically, the diameter of the test tire 82 and the test tire 8 stored in advance and stored so that the first mark 134 coincides with the optical axis of the slip measurement camera 108.
2, the position of the slip measurement camera 108, the position of the movable base 36, and the like.
Start position (rotational position), slip measurement camera 108
And / or the position of the moving base 36 is calculated.

Then, the tire traveling device 20 is moved in the reverse direction (the direction of the arrow L) to stop the tire traveling device 20 at the start position, and at the same time, the test tire 82 is raised and separated from the road surface 16 once, and is obtained by calculation. The test tire 82 is stopped at the start position (rotational position) for slip measurement, and the positioning of the slip measurement camera 108 and / or the movement base 36 is performed.

In step 118, the test tire 82 is again brought into contact with the road surface 16, and the tire traveling device 20 is moved in the direction of arrow R. Thereby, the test tire 82 rolls on the road surface 16 and the road surface 92 with the built-in measuring instrument.

When the test tire 82 passes on the road surface 92 with a built-in measuring instrument, the slip measuring camera 108
The photographing of the tire tread (mark 134) is performed until and after the tire is separated from the ground.

[0108] Then, the control device 23 makes the mark 134 based on the data sent from the slip measurement camera 108.
Are stored over time (see FIG. 12. Sx indicates the slip amount in the road surface width direction, and Sy indicates the slip amount in the road surface longitudinal direction).

In step 120, the controller 23 calculates and stores the wear energy at the measurement point based on the magnitude of the force on the road surface and the amount of slip of the mark 134.

The wear energy (EW) can be calculated based on the following equation, for example.

[0111]

(Equation 1) L: Contact length (see FIG. 9; distance between two points ab where the line KL passing through the mark 134 and parallel to the tire equatorial plane CL and the outer contour line of the footprint intersect)

In step 122, it is determined whether the calculation and storage of the wear energy has been completed for all the measurement points. If it is determined that the calculation and storage of the wear energy has not been completed for all the measurement points, the process returns to step 108, and the same processing is performed for the next measurement point. On the other hand, if it is determined that the calculation and storage of the wear energy has been completed for all the measurement points, step 124
Proceed to.

In step 124, it is determined whether or not the measurement has been completed under all the measurement conditions. If it is determined that the measurement has not been completed under all the measurement conditions, the process returns to step 106, and the process is changed to the next measurement condition and the process proceeds. On the other hand, when it is determined that the measurement has been completed under all the measurement conditions, the process is terminated.

As described above, in the present embodiment, the three-component force at each measurement point of the test tire 82 is measured under various test conditions in which the slip angle (SA), camber angle (CA), load, braking / driving force, etc. are variously changed. Measurement of slip and slip, and calculation of wear energy can be performed fully automatically.

In the above embodiment, all the marks 1
34 was photographed by a camera 116 for coordinate measurement, and each mark position was converted to coordinates.
4 may be taken.

Further, a force measured by a change in the road surface temperature,
In order not to cause an error in the amount of slip, for example, the temperature near the measuring instrument built-in road surface 92 is measured by a temperature sensor, and the air conditioner is controlled so that the road surface temperature at the time of the test does not change. The blowing wind may be applied to the road surface.

[0117]

As described above, in the tire tread tread measuring device and the tread tread measuring method of the present invention, the force and the amount of slip acting on a number of measurement points on the tire tread are automatically determined. In addition, there is an excellent effect that measurement can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a plan view of an apparatus for measuring a tread of a tire tread according to an embodiment of the present invention.

FIG. 2 is a front view of the grounding section measuring device shown in FIG.

FIG. 3 is a right side view of the grounding section measuring device shown in FIG. 1;

FIG. 4 is a plan view of a road surface with a built-in measuring instrument.

FIG. 5 is an explanatory diagram for explaining a start position.

FIG. 6 is a block diagram illustrating a configuration of a control system.

FIG. 7 is a control flowchart.

FIG. 8 is a plan view of a template used when performing marking.

FIG. 9 is a footprint of a test tire.

FIG. 10 is an explanatory diagram illustrating a relationship between a mark and a contact portion of a three-component force sensor.

FIG. 11 shows measurement data of forces in three directions.

FIG. 12 shows measurement data of a slip amount of a mark.

FIG. 13 is an explanatory diagram showing a relationship between a conventional mark and a contact portion of a three-component force sensor.

[Explanation of symbols]

 Reference Signs List 10 ground contact measuring device 16 road surface 21 encoder (control means) 22 servo motor (control means) 23 control device (control means) 38 servo motor (control means) 43 encoder (control means) 49 servo motor (control means) 61 rotary encoder (Control means) 63 Encoder (Control means) 72 Servo motor (Control means) 81 Rotary encoder (Control means) 82 Test tire 86 Suppression drive servomotor (Control means) 87 Rotary encoder (Control means) 89 Load cell (Control means) 92 Road surface with built-in measuring instrument 94 Servo motor (control means) 93 Encoder (control means) 102 3-component force sensor (force sensor) 106 Camera for measuring deviation (control means) 108 Camera for measuring slip (reading sensor) 116 Camera for measuring coordinate ( Control means) 134 mark (measurement point)

Claims (6)

[Claims] 1. A test tire is rolled on a road surface, and when a measurement point in the tire tread is in contact with the road surface, a magnitude of a force acting on the measurement point in at least a direction along the road surface is measured by a force sensor. A tire contact portion measuring device for detecting and measuring the amount of slip of the measurement point with respect to the road surface by using a reading sensor, wherein the magnitude of the force and the slip are measured for each of a plurality of measurement points. Control means for reading and storing the position coordinates of all the measurement points in advance when sequentially detecting the amounts, and automatically adjusting at least one of the start position of the test tire and the position of the force sensor based on the read position coordinates; When detecting the magnitude of the force and the amount of slip for each of the measurement points, the control unit controls the test tire so that the measurement point comes into contact with the force sensor. Automatically adjusting at least one of a start position and a position of the force sensor, and thereafter, rolling the test tire on a road surface to detect the magnitude of the force acting on the measurement point and the slip amount. Treading device for tire tread. 2. When the relative distance between the measurement point and the force sensor when the measurement point contacts the force sensor is larger than a predetermined reference dimension, the control means starts the test tire. The tire tread tread measuring device according to claim 1, wherein re-measurement is performed after at least one of the position and the position of the force sensor is automatically adjusted again. 3. A test tire is rolled on a road surface, and a force sensor is used to measure a magnitude of a force acting at least at a direction along the road surface when the measurement point in the tire tread contacts the road surface. A method for measuring the contact area of a tire, wherein the magnitude of the force and the slip are measured for each of a plurality of measurement points by using a reading sensor to detect the amount of slippage of the measurement point with respect to the road surface. When sequentially detecting the amount, the position coordinates of all the measuring points are stored in advance, and when detecting the magnitude of the force and the amount of slip for each of the measuring points, the measuring point is the force sensor. After automatically adjusting at least one of the start position of the test tire and the position of the force sensor so as to contact the test tire, the magnitude of the force acting on the measurement point by rolling the test tire on a road surface is adjusted. And said Grounding portion measuring method of the tire tread which is characterized by detecting the amount of Ri. 4. If the relative distance between the measurement point and the force sensor when the measurement point contacts the force sensor is larger than a predetermined reference dimension, the control means starts the test tire. The method for measuring a contact portion of a tire tread according to claim 3, wherein the measurement is performed again after automatically adjusting at least one of the position and the position of the force sensor again. 5. The method according to claim 3, wherein a mark readable by the reading sensor is provided to the measurement point using a template. 6. The method according to claim 5, wherein a shape and a size of the mark are the same as a shape and a size of a portion where the force sensor contacts the tread surface.