JP2001056215A - Wear amount measuring device for tire and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wear amount measuring device for a tire capable of grasping a wear amount quantitatively. SOLUTION: This wear amount measuring device for a tire consists of a tread face measuring device 2 having a displacement sensor 4 which is arranged toward a tread face Ta of the held tire T and can detect a distance up to the tread face Ta and a travel means 5 capable of moving this displacement sensor 4 relatively with the tire T in at least peripheral direction of the tire and a controller 3 which receives data of the displacement sensor 4 to judge a three-dimensional shape of a tread pattern including a groove depth in a measurement scope of the tread face Ta by computation and stores this pattern data. Moreover, the controller 3 compares pattern data of a new tire with pattern data of used tire to calculate a wear amount of the tire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for measuring the amount of wear of a tire, which can quantitatively determine the amount of wear of the tire.

[0002]

2. Description of the Related Art The amount of tire wear can be determined by determining the optimal tire rotation time,
This data is valuable in improving tire life, and in developing tread rubber compounding and tread patterns. Conventionally, as a method of measuring the amount of wear on the land portion (block, rib, etc.) of such a tire, it is common to measure the remaining amount of a tread groove adjacent to the land portion using a depth gauge or the like. Was.

[0003] However, in the measurement with a depth gauge, the measuring method, position, and the like differ depending on the measurer,
Also, there is a tendency for a difference in the reading of the gauge. In addition, as for uneven wear of the land portion, the quality is usually judged based on the sense of the measurer, so that it tends to be difficult to quantitatively grasp the wear amount.

The present invention has been devised in view of the above-mentioned problems, and a tire wear amount measuring apparatus and method capable of uniformly measuring the wear amount of a land portion of a tire and quantitatively grasping the same. It is intended to provide.

[0005]

According to a first aspect of the present invention, there is provided a displacement sensor arranged toward a tread surface of a held tire and capable of detecting a distance to the tread surface; A tread surface measuring tool having a moving means for moving a sensor relative to the tire in the tire circumferential direction and the tire axial direction, and measuring and measuring the tread surface by receiving data from the displacement sensor of the tread surface measuring tool The control device determines a three-dimensional shape of the tread pattern including the groove depth in the range, and stores the pattern data. The control device compares the pattern data of a new tire with the pattern data of a used tire. A tire wear amount measuring device, wherein the tire wear amount is calculated.

[0006] The invention according to claim 2 is characterized in that the amount of wear of the tire is calculated based on the volume of the land portion of the tire obtained from the pattern data of the new tire and the volume of the land portion obtained from the pattern data of the used tire. The tire wear amount measuring device according to claim 1, wherein the tire wear amount measurement device is calculated as a difference from a volume.

According to a third aspect of the present invention, there is provided a displacement sensor disposed toward a tread surface of a held tire and capable of detecting a distance to the tread surface. Acquiring the data of the tread surface in the measurement range by relatively moving, and determining the three-dimensional shape of the tread pattern including the groove depth in the measurement range of the tread surface by receiving and calculating the data; Calculating a tire wear amount by comparing the pattern data of the new tire with the pattern data of the used tire.

According to a fourth aspect of the present invention, in the step of calculating the amount of wear of the tire, the step of calculating a wear amount of the tire includes obtaining a land volume of the tire obtained from pattern data of a new tire and pattern data of a used tire. The tire wear amount measuring method according to claim 3, wherein the tire wear amount is obtained as a difference from the volume of the land portion.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a tire wear amount measuring device 1 of the present embodiment includes a tread surface measuring tool 2 and a control device 3.

[0010] The tread surface measuring device 2 includes a displacement sensor 4 disposed toward a tread surface Ta of a held tire T and capable of detecting a distance to the tread surface Ta. And moving means 5 for moving around the rotation axis CL of the tire in the circumferential direction and relatively to the tire T. In the present embodiment, the tire T is mounted and held on a vertically adjustable support shaft 6 whose height can be adjusted.

As the displacement sensor 4, a non-contact type two-dimensional displacement sensor is used in this embodiment. This non-contact type two-dimensional displacement sensor includes a light emitting unit that emits detection light such as laser light toward a tread surface Ta of a tire T, and a light receiving unit that receives light reflected by the tread surface Ta. (Neither is shown), and the distance to the tread surface Ta can be measured in a state away from the tread surface Ta. Further, the two-dimensional displacement sensor 4 of the present embodiment uses a plurality of pairs of measuring units each having a pair of the light emitting unit and the light receiving unit arranged in the width direction of the tread surface Ta. Therefore, the distance to the tread surface Ta can be measured over a predetermined width W of the tread surface Ta.

FIG. 4 shows data obtained from such a displacement sensor 4 as two-dimensional (X-
Y) The display on the coordinates is illustrated. As described above, the displacement sensor 4 can detect a predetermined width in the tire axial direction, in this example, a width in the tire axial direction larger than the width of one block B disposed on the tread surface Ta. Can be detected including the grooves G on both sides in the tire axial direction. Therefore, one block B can be efficiently scanned in a shorter time than in the case where detection is performed using a one-dimensional sensor. Such data corresponds to a part of the contour of the tire meridian section.

In the present embodiment, the moving means 5 moves the displacement sensor 4 around the rotation axis CL of the held tire T. That is, the moving means 5 includes a traveling body 5A that can travel by the electric motor M1, one end of which is fixed to the traveling body 5A, and the other end of which is the support shaft 6A.
Arm 5 having a bearing portion 7 pivotally mounted on the arm 5
B. Accordingly, by causing the traveling body 5A to travel, the displacement sensor 4 can move around the tread surface Ta around the tire rotation axis CL. The swing arm 5B
A gear 9 is fixed to the bearing portion 7 and a detection gear 11 of a rotation sensor 10 such as an encoder is meshed with the gear 9. Therefore, when the traveling body travels, the rotation amount corresponding to the movement is detected by the rotation sensor 1.
0 is detected.

As shown in FIG. 2, for example, the control device 3 previously stores an arithmetic processing unit 3a for performing various operations and various existing data such as a processing procedure of the arithmetic processing unit 3a. A first storage unit 3b composed of a ROM or the like, a second storage unit 3c composed of a RAM or the like as a temporary storage memory for work, and an input port 3d and an output port 3e are shown. Are appropriately linked by a data bus. The input port 3d receives signals from the displacement sensor 4, the rotation sensor 10, and input means 17 such as a keyboard for performing various operations and instructions.
The output port 3e is, for example, C
A monitor 19 such as an RT, a printer 20 capable of printing measurement results and the like are appropriately connected, and are configured to output various signals to them. Note that, for the control device 3, for example, various types of computers, particularly, personal computers and the like can be suitably used.

The operation procedure of the apparatus of this embodiment having the above-mentioned configuration will be described with reference to the flowchart shown in FIG. First, the used tire T is attached to the support shaft 6 of the tread surface measuring tool 2. The measurement range of the tread surface 2a of the displacement sensor 4 is adjusted by appropriately changing the height of the support shaft 6. Next, the traveling body 5A is caused to travel around the rotation axis of the tire. Thereby, the displacement sensor 4 also moves around the tread surface Ta (Step S).
1). The amount of movement of the displacement sensor 4 around the rotation axis CL of the tire at this time is input from the rotation sensor 10 to the control device 3.

The control device 3 determines whether or not the rotation amount has reached a predetermined amount (equal pitch) (step S2). When it is determined that the pitch has reached the same pitch (Y in step S2), the control device 3 takes in the data from the displacement sensor 4 at that timing and stores it in the second storage unit 3c. In the present embodiment, this process is repeated until data on one round of the tire is captured (step S4). The number of times of data sampling from such a displacement sensor 4 is, for example, 3000 to
It is preferable to determine the equal pitch so as to be about 40,000 times.

Next, the control device 3 receives the data from the displacement sensor 4 and performs a predetermined calculation to determine the three-dimensional shape of the tread pattern including the groove depth in the measurement range of the tread surface Ta. The data obtained from the displacement sensor 4 is
It is a set of many point data on the outer surface of the tread surface Ta. Regarding a method of three-dimensionally forming the pattern of the tread surface Ta from these many point data, for example, data at the same distance in the X direction (in this example, the tire axis direction) is connected at a data capture pitch interval (mutually). By associating), the two-dimensional data can be made three-dimensional. Thereby, as shown in FIG. 5, the pattern of the tread surface Ta is specified in three dimensions (XYZ) in the measurement range, and this is stored in the second storage unit 3c as pattern data,
It is displayed on a monitor or the like as needed.

Next, by comparing the pattern data of the new tire with the pattern data of the used tire, which is obtained and stored in advance in the same manner as described above,
The wear amount of the tire is measured (Step S5). For example,
In such a comparison, as shown in FIG. 6, by displaying the difference between the patterns on the monitor 19, that is, by displaying the worn portion N by coloring or the like, the worn portion N can be visually represented in three dimensions. .

In this embodiment, the volume of the block B is calculated from the determined three-dimensional shape of the block B as the amount of wear of the tire, and the volume of the block B obtained in advance for a new tire is calculated. FIG. 4 illustrates an example in which the amount of wear per block is quantitatively grasped as a wear volume by subtracting the wear amount from each block. The volume of the block B can be defined, for example, as a region located outside a plane passing through the lowest point of the depth of the groove G dividing the four sides of the block. The calculation of the volume is performed by the arithmetic processing unit 3a based on the three-dimensional pattern data.

As described above, in this embodiment, since the amount of wear of the tire can be quantitatively grasped as a physical volume, the method of measuring the amount of wear is independent of the subjectivity of the measurer. Can be made uniform, and the wear state can be grasped quantitatively. Therefore, it is possible to grasp valuable tire rotation time and the like for each tire, and to analyze valuable data such as abrasion characteristics based on tread rubber composition and tread pattern shape, thereby contributing to obtaining valuable data.

FIG. 7 shows another embodiment of the tread surface measuring device 2. The tread surface measuring tool 2 of the present embodiment is, for example, a first sensor for moving the displacement sensor 4 disposed on the base 2a and the tire T held on the horizontal support shaft 6 in the present embodiment around the rotation axis thereof. And the moving means 21 of FIG. The tire T is held by attaching its rim J to one end of the support shaft 6. The other end of the support shaft 6 is rotatably and cantilevered by a bearing 22. The displacement sensor 4
Is the same as that of the above embodiment.

In the present embodiment, the first moving means 21 comprises the support shaft 6 and an electric motor M2 for driving the support shaft 6 to rotate. The torque of the electric motor M2 is applied to the support shaft 6 via an endless string 23 such as a belt or a chain.
Is transmitted to the other end. Therefore, when the electric motor M2 is driven,
The tire T rotates around the rotation axis of the tire T together with the support shaft 6 and can form relative movement in the tire circumferential direction with the stationary displacement sensor 4. The rotation amount of the support shaft 6 is similarly detected by the rotation sensor 10.

The displacement sensor 4 is mounted on a mounting plate 25, and the base 2a is moved via the second moving means 27 for moving the mounting plate 25 in the axial direction of the held tire T. It is arranged in. As the second moving means 27, for example, a ball screw moving mechanism is employed.
That is, the screw shaft 29 and the guide shaft 30 arranged side by side,
The mounting plate 11 has a nut portion 31 and a slider 32 guided by these components, and the mounting plate 11 can be moved along the tire axial direction by rotating the screw shaft 29 with the electric motor M3. Therefore, relative displacement in the tire axial direction is formed between the displacement sensor 4 and the tire T at rest. As described above, the tread surface measuring tool 2 may have various configurations, and for example, may be configured to be able to measure a tire as it is mounted on an automobile.

Although the embodiment of the present invention has been described above, for example, the measurement range of the displacement sensor may be a part in the tire circumferential direction, and the wear amount of only a specific block may be detected. Also, a one-dimensional sensor can be used as the displacement sensor 4. In this case, the moving means 5 includes a configuration for finely moving the displacement sensor 4 in the X direction (tire axis direction) in this example.

[0025]

As described above, according to the apparatus and method of the present invention, the measurement of the wear amount of the land portion of the tire can be made uniform and can be quantitatively grasped. Therefore, it is possible to contribute to the improvement of the tire life by grasping the optimal tire rotation time for each tire, and to obtain valuable data on the blending of the tread rubber and the development of the tread pattern.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a wear amount measuring device according to an embodiment.

FIG. 2 is a block diagram illustrating a control device.

FIG. 3 is a flowchart illustrating a processing procedure of a control device.

FIG. 4 is a two-dimensional graph showing displacement sensor data.

FIG. 5 is a graph showing data of a displacement sensor in three dimensions.

FIG. 6 is an exemplary view showing a three-dimensional block (new or used) displayed on a monitor.

FIG. 7 is a perspective view showing another embodiment of the tread surface measuring tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wear amount measuring device 2 Tread surface measuring tool 3 Control device 4 Displacement sensor 5 Moving means

Claims (4)

[Claims] 1. A displacement sensor arranged toward a tread surface of a held tire and capable of detecting a distance to the tread surface, and moving the displacement sensor relative to the tire at least in a tire circumferential direction. A tread surface measuring tool having moving means, and receiving and calculating data of the displacement sensor of the tread surface measuring tool, determining a three-dimensional shape of a tread pattern including a groove depth in a measurement range of the tread surface; A tire wear amount measuring device, comprising: a control device for storing data; wherein the control device calculates a tire wear amount by comparing pattern data of a new tire with pattern data of a used tire. . 2. The tire wear amount is calculated as a difference between a land volume of the tire obtained from pattern data of a new tire and a volume of the land obtained from pattern data of a used tire. The tire wear amount measuring device according to claim 1, wherein: 3. A measurement range of a measurement range is set by moving a displacement sensor arranged toward a tread surface of a held tire and capable of detecting a distance to the tread surface relative to the tire at least in a tire circumferential direction. A step of obtaining data of the tread surface; a step of receiving and calculating the data to determine a three-dimensional shape of the tread pattern including the groove depth in the measurement range of the tread surface; and a step of using pattern data of a new tire. Calculating the amount of wear of the tire by comparing it with pattern data of the tire. 4. The step of calculating the amount of wear of the tire includes the step of calculating a volume of a land portion of the tire obtained from pattern data of a new tire and a volume of the land portion obtained from pattern data of a used tire. 4. The method according to claim 3, wherein the difference is obtained.