JP2021172105A - Tire measuring method and tire display method - Google Patents

Abstract

To provide a method for measuring a shape of a rotated tire in detail, and a tire display method.SOLUTION: There is provided a method for measuring a profile shape of a tire 1. The method includes: a first step S1 of acquiring first information F1 on the profile shape of the tire 1 in a state in which the tire 1 is rotated or stopped at first velocity V1; a second step S2 of acquiring second information F2 on the profile shape of the tire 1 in a state in which the tire 1 is rotated at second velocity V2 different from the first velocity V1; and a third step S3 of acquiring third information F3 on the profile shape of the tier 1 on the basis of the first information F1 and the second information F2.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for measuring a tire profile shape and a method for displaying a tire shape.

Conventionally, a method for measuring the profile shape of a tire has been known. For example, in Patent Document 1 below, the outer peripheral surface of a rotating tire is scanned by a laser displacement meter at a large number of points for each small circumference pitch of the circumference line, and the predicted positions of the outer circumference surface of each small circumference pitch are connected. Describes a measuring method for obtaining a rotating tire profile.

Japanese Unexamined Patent Publication No. 2002-116012

However, since the measuring method of Patent Document 1 measures the tire at one point on the opposite side of the ground contact surface of the tire, it is not possible to measure the deformation of the tread surface of the tire that occurs at the time of ground contact.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a method capable of measuring the shape of a rotating tire in detail and a method of displaying the tire.

The present invention is a method for measuring the profile shape of a tire, the first step of acquiring the first information regarding the profile shape of the tire in a state where the tire is rotated or stopped at the first speed, and the above-mentioned. Based on the second step of acquiring the second information regarding the profile shape of the tire in a state where the tire is rotated at a second speed different from the first speed, and the first information and the second information, the said It is characterized by including a third step of acquiring a third information regarding the profile shape of the tire.

In the tire measuring method of the present invention, it is desirable that the third step obtains the third information based on the difference between the first information and the second information.

In the tire measuring method of the present invention, it is desirable that the first information and the second information are a first image and a second image obtained by photographing the tread surface of the tire, respectively.

In the tire measuring method of the present invention, it is desirable that in the first step and the second step, the first image and the second image are photographed by a stereo method with two cameras, respectively.

In the tire measuring method of the present invention, the first step and the second step each acquire the first image and the second image so as to include a plurality of marks provided in advance on the tread surface. In the third step, it is desirable to acquire the third information based on the difference between the position of the mark in the first image and the position of the mark in the second image.

In the tire measuring method of the present invention, the first step and the second step synchronize the shooting timings of the first image and the second image based on the marks provided on the rotation shaft to which the tire is attached. Is desirable.

The present invention is a method for displaying the shape of a tire, the first step of acquiring a first image of the tread surface of the tire in a state where the tire is rotated or stopped at the first speed, and The difference between the second step of acquiring a second image of the tread surface in a state where the tire is rotated at a second speed different from the first speed and the difference between the first image and the second image. Based on this, it is characterized by including a third step of acquiring a third image relating to the shape of the tire and a fourth step of displaying the third image.

In the tire display method of the present invention, it is desirable that the third image is the difference between the land portion of the tread surface in the first image and the second image.

The method for measuring a tire of the present invention is different from the first step of acquiring the first information regarding the profile shape of the tire in a state where the tire is rotated or stopped at the first speed, and the tire of the tire at the first speed. Based on the second step of acquiring the second information regarding the profile shape of the tire in the state of being rotated at the second speed, and the first information and the second information, the third information regarding the profile shape of the tire is obtained. Includes a third step to acquire.

In such a tire measuring method, since the third information is acquired by comparing the first information and the second information, it is possible to accurately measure the change in the profile shape in the tire circumferential direction. Therefore, the tire measuring method of the present invention can measure the shape of a rotating tire in detail.

The tire display method of the present invention includes a first step of acquiring a first image of a tread surface of the tire in a state where the tire is rotated or stopped at the first speed, and the tire is referred to as the first speed. Is related to the shape of the tire based on the difference between the second step of acquiring the second image of the tread surface in a state of being rotated at different second speeds and the first image and the second image. The third step of acquiring the three images and the fourth step of displaying the third image are included.

In such a tire display method, since the first image and the second image are compared and the third image is acquired, the change in the shape in the tire circumferential direction can be displayed as a surface. Therefore, the tire display method of the present invention can display the shape of the rotating tire in detail.

It is a conceptual diagram which shows one Embodiment of the state which carries out the tire measuring method of this invention. It is a flowchart of a tire measurement method. It is a flowchart of a tire display method. It is a schematic diagram which shows an example of the 3rd image.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual diagram showing a state in which the method for measuring the tire 1 of the present embodiment is being implemented. As shown in FIG. 1, the method for measuring the tire 1 of the present embodiment is a method for measuring the profile shape of the tire 1. In the method for measuring the tire 1 of the present embodiment, the tire 1 in the normal state is attached to the rotating shaft 3 of the measuring device 2, and the rotating drum 4 is grounded with a normal load applied.

Here, the "normal state" is a state in which the tire 1 is rim-assembled on the normal rim R and is adjusted to the normal internal pressure without load. "Regular rim R" is a rim defined for each tire in the standard system including the standard on which tire 1 is based. For example, "standard rim" for JATTA and "Design Rim" for TRA. ", If it is ETRTO, it is" Measuring Rim ".

"Regular internal pressure" is the air pressure defined for each tire in the standard system including the standard on which Tire 1 is based. For JATMA, "maximum air pressure", for TRA, the table "TIRE LOAD LIMITS" The maximum value described in "AT VARIOUS COLD INFLATION PRESSURES", or "INFLATION PRESSURE" for ETRTO.

"Regular load" is the load defined for each tire in the standard system including the standard on which Tire 1 is based. For JATMA, "maximum load capacity", and for TRA, the table "TIRE LOAD". The maximum value described in "LIMITS AT VARIOUS COLD INFLATION PRESSURES", or "LOAD CAPACITY" for ETRTO.

FIG. 2 is a flowchart of the measurement method of the tire 1 of the present embodiment. As shown in FIGS. 1 and 2, in the method of measuring the tire 1 of the present embodiment, first, in a state where the tire 1 is rotated or stopped at the first speed V1, the first information F1 regarding the profile shape of the tire 1 is obtained. The first step S1 is performed.

The method for measuring the tire 1 of the present embodiment is a second method of acquiring second information F2 regarding the profile shape of the tire 1 in a state where the tire 1 is rotated at a second speed V2 different from the first speed V1. Step S2 is performed. In such a second step S2, the second information F2 in a state different from that of the first information F1 can be acquired.

In the method for measuring the tire 1 of the present embodiment, a third step S3 for acquiring the third information F3 regarding the profile shape of the tire 1 is then performed based on the first information F1 and the second information F2. In such a method of measuring the tire 1, since the first information F1 and the second information F2 are compared and the third information F3 is acquired, it is possible to accurately measure the change in the profile shape in the tire circumferential direction. can. Therefore, the method for measuring the tire 1 of the present embodiment can measure the shape of the rotating tire 1 in detail.

In a more preferred embodiment, the measuring device 2 includes a camera 5 capable of photographing the tread surface 1a near the ground contact surface of the tire 1. It is desirable that the camera 5 includes two cameras 5 capable of photographing by the stereo method. The camera 5 includes, for example, a first camera 5A and a second camera 5B separated by a predetermined distance in the axial direction of the rotation axis 3. Such a camera 5 can grasp the shape of the tread surface 1a three-dimensionally.

The camera 5 captures, for example, the tread surface 1a immediately after touchdown in the tire circumferential direction. It is desirable that the shooting position of the camera 5 can be changed to an arbitrary position in the tire circumferential direction. Such a camera 5 can grasp the shape of the tire 1 in the tire circumferential direction at an arbitrary position. The camera 5 may be, for example, a sensor capable of recognizing a three-dimensional shape of a surface.

The first information F1 and the second information F2 of the present embodiment are the first image G1 and the second image G2 obtained by photographing the tread surface 1a of the tire 1, respectively. Since such a first image G1 and a second image G2 can be photographed by using the camera 5, acquisition is easy.

In the first step S1 of the present embodiment, the first image G1 is photographed by the stereo method with two cameras 5. Further, in the second step S2 of the present embodiment, the second image G2 is photographed by the stereo method with two cameras 5. It is desirable that the first step S1 and the second step S2 take pictures using a high-speed camera or a stroboscope as the camera 5. In such a first step S1 and a second step S2, the shape of the tread surface 1a of the rotating tire 1 can be three-dimensionally photographed.

In the first step S1 and the second step S2, it is desirable to acquire the first image G1 and the second image G2 so as to include a plurality of marks 6 provided in advance on the tread surface 1a, respectively. The mark 6 is, for example, a paint randomly sprayed on the tread surface 1a. The mark 6 is formed in a mottled pattern, for example. Such a mark 6 is useful for grasping the shape of the tread surface 1a in detail.

In the third step S3 of the present embodiment, the third information F3 is acquired based on the difference between the first information F1 and the second information F2. Such a third step S3 shows the amount of displacement or the amount of strain between the tread surface 1a in the state where the tire 1 is rotated or stopped at the first speed V1 and the tread surface 1a in the state where the tire 1 is rotated or stopped at the second speed V2. The third information F3 can be acquired.

In the third step S3, it is desirable to acquire the third information F3 based on the difference between the position of the mark 6 of the first image G1 and the position of the mark 6 of the second image G2. The third information F3 is, for example, a displacement amount indicating unevenness at the position of the mark 6. The third information F3 may be, for example, a strain amount which is a movement amount in the three axial directions at the position of the mark 6. In such a third step S3, the same positions of the first image G1 and the second image G2 can be compared, so that the profile shape of the tread surface 1a can be measured accurately.

In the first step S1 and the second step S2 of the present embodiment, the shooting timings of the first image G1 and the second image G2 are synchronized based on the mark 7 provided on the rotating shaft 3 to which the tire 1 is attached. The mark 7 is, for example, a reflective tape attached to the rotating shaft 3. In the first step S1 and the second step S2, it is desirable that the imaging timing is synchronized by a sensor (not shown) capable of detecting the mark 7. Such a mark 7 makes it easy to photograph the same position in the first image G1 and the second image G2, and is useful for accurately measuring the profile shape of the tread surface 1a.

FIG. 3 is a flowchart of a display method of the tire 1 of the present embodiment. As shown in FIGS. 1 and 3, in the display method of the tire 1 of the present embodiment, first, the tread surface 1a of the tire 1 is photographed in a state where the tire 1 is rotated or stopped at the first speed V1. 1 The first step S1A for acquiring the image G1 is performed.

Next, in the display method of the tire 1 of the present embodiment, a second image G2 obtained by photographing the tread surface 1a in a state where the tire 1 is rotated at a second speed V2 different from the first speed V1 is acquired. Step S2A is performed. In such a second step S2A, the second image G2 in a state different from that of the first image G1 can be acquired.

Next, in the display method of the tire 1 of the present embodiment, a third step S3A for acquiring a third image G3 regarding the shape of the tire 1 is performed based on the difference between the first image G1 and the second image G2. Such a third step S3A shows the amount of displacement or the amount of strain between the tread surface 1a in the state where the tire 1 is rotated or stopped at the first speed V1 and the tread surface 1a in the state where the tire 1 is rotated or stopped at the second speed V2. The third image G3 can be acquired.

In the display method of the tire 1 of the present embodiment, the fourth step S4A for displaying the third image G3 is then performed. In such a display method of the tire 1, since the first image G1 and the second image G2 are compared and the third image G3 is acquired, the change in the shape in the tire circumferential direction can be displayed as a surface. .. Therefore, the display method of the tire 1 of the present embodiment can display the shape of the rotating tire 1 in detail.

FIG. 4 is a schematic view showing an example of the third image G3. As shown in FIG. 4, the third image G3 of the present embodiment is the difference between the land portion of the tread surface 1a in the first image G1 and the second image G2. In such a third image G3, the calculation of the groove portion can be omitted, so that the calculation time can be shortened. Further, the third image G3 has good visibility because the display of the groove portion is omitted.

In the third image G3 of the present embodiment, the size of the unevenness of the tread surface 1a is divided and displayed according to the level 8 of the unevenness. The level 8 of the unevenness is, for example, the amount of displacement between the tread surface 1a in the state where the tire 1 is rotated or stopped at the first speed V1 and the tread surface 1a in the state where the tire 1 is rotated at the second speed V2. In FIG. 4, the level 8 of the unevenness is divided into 6 stages and displayed, but it is desirable that the level 8 of the unevenness is displayed by changing the color steplessly. Such a third image G3 is useful for visually grasping the change in the shape in the tire circumferential direction.

Although the particularly preferable embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and can be modified into various embodiments.

1 tire

Claims (8)

A method for measuring the profile shape of a tire,
The first step of acquiring the first information regarding the profile shape of the tire while the tire is rotated or stopped at the first speed, and
A second step of acquiring the second information regarding the profile shape of the tire in a state where the tire is rotated at a second speed different from the first speed, and
A third step of acquiring a third information regarding the profile shape of the tire based on the first information and the second information is included.
How to measure tires. The tire measuring method according to claim 1, wherein the third step acquires the third information based on the difference between the first information and the second information. The method for measuring a tire according to claim 1 or 2, wherein the first information and the second information are a first image and a second image obtained by photographing the tread surface of the tire, respectively. The method for measuring a tire according to claim 3, wherein in the first step and the second step, the first image and the second image are photographed by a stereo method with two cameras, respectively. In the first step and the second step, the first image and the second image are acquired so as to include a plurality of marks provided in advance on the tread surface, respectively.
The tire according to claim 3 or 4, wherein the third step acquires the third information based on the difference between the position of the mark in the first image and the position of the mark in the second image. Measuring method. The first step and the second step are any of claims 3 to 5, wherein the shooting timings of the first image and the second image are synchronized based on the mark provided on the rotation shaft to which the tire is attached. The method for measuring a tire according to item 1. It ’s a way to display the shape of a tire.
The first step of acquiring a first image of the tread surface of the tire with the tire rotated or stopped at the first speed, and
A second step of acquiring a second image of the tread surface in a state where the tire is rotated at a second speed different from the first speed, and
A third step of acquiring a third image relating to the shape of the tire based on the difference between the first image and the second image, and
Including a fourth step of displaying the third image.
How to display tires. The method for displaying a tire according to claim 7, wherein the third image is a difference between the land portion of the tread surface in the first image and the second image.

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