JP2006290290A - Tire balance device and tire balance adjusting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide tire balance device and tire balance adjusting method for determining peripheral direction and cross section direction positions of a lightest part of a tire. <P>SOLUTION: Distances up to internal surface and external surface of the tire of tire cross section direction and tire peripheral direction are measured by a thickness distribution measuring machine 1. The distance data is inputted into a thickness arithmetic part 13 of a distance data processing device 12 to calculate thickness of each part of the tire of the tire cross section direction and tire peripheral direction. In a weight arithmetic part 14, weight of each part of the tire of the tire cross section direction and tire peripheral direction is calculated from thickness of each part of the tire, and the position of a center gravity of the tire is determined from weight of each part of the tire. Peripheral direction and cross section direction positions of light part and heavy part of the tire are determined from a thickness distribution, weight distribution and the position of the center of gravity of the tire. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tire balance device and a tire balance adjustment method that can determine the positions of the lightest and heaviest parts of a tire that are unbalanced positions of the tire.

  Tires have a non-uniform weight distribution in the circumferential direction of the tire due to external factors such as the vulcanization temperature in the tire manufacturing or viscoelastic characteristics of the rubber material. The tire balance has been improved to increase the uniformity of the tire. However, in order to improve the tire balance, it is necessary to know which part of the tire is light and which part is heavy. Therefore, the lightest and heaviest parts in the weight distribution in the circumferential direction of the tire are detected by a static balance measuring device.

  FIG. 12 is a cross-sectional view of the static balance measuring apparatus. In the static balance measuring device 20, load cells 21 and 22 (23 and 24) are disposed on the main body 28, and a weighing table 26 is disposed on the load cell. The tire T is set on the weighing table 26 after being aligned so that the center axis position of the tire T becomes the center position of the weighing table 26. The tire T here is not incorporated in the wheel, but in a single state after vulcanization.

FIG. 13 is a plan view of the static balance measuring device when the weighing table 26 is removed. On the main body 28, two load cells 21 and 22 are arranged in the X direction, and two load cells 23 and 24 are arranged in the Y direction. When the tire T is set on the weighing table 26, the unbalanced force in the X direction of the tire T is detected from the difference in force applied to the two load cells 21, 22 arranged in the X direction, and the tire T is arranged in the Y direction. The unbalanced force in the Y direction of the tire T is detected from the difference in force applied to the two load cells 23 and 24. Each detected unbalance force is read and calculated by a calculation control unit (not shown), and the lightest portion and the heaviest portion of the tire T are synthesized by combining the unbalance force in the X direction and the unbalance force in the Y direction. The position in the circumferential direction is obtained.
Japanese Patent Application No. 2003-50123

  However, in the conventional static balance measuring device, the position of the lightest part and the heaviest part in the circumferential direction as the resultant force of the entire tire is known, but it is not known which part in the tire cross-sectional direction is light and which part is heavy. For this reason, there is a problem that it is difficult to determine the means for improving the tire balance without knowing which process of the tire manufacturing should be improved.

  The present invention has been made in view of such problems, and an object of the present invention is to determine the positions in the circumferential direction and the cross-sectional direction of the lightest and heaviest parts of the tire that are unbalanced positions of the tire. An object of the present invention is to provide a tire balance device and a tire balance adjustment method that can be used.

  In order to achieve the above object, a tire balance device according to the present invention includes a thickness distribution measuring machine that measures the distance to the inner surface of the tire and the distance to the outer surface of the tire along the circumferential direction and the cross-sectional direction, and the thickness distribution measurement. Thickness distribution data in the tire circumferential direction and cross-sectional direction is obtained based on the distance data from the machine, and the tire circumferential direction based on the tire thickness distribution data in the circumferential direction and the cross-sectional direction and preset specific gravity distribution data. And a distance data processing device for obtaining weight distribution data in the cross-sectional direction, outputting the weight distribution data, obtaining the center of gravity of the tire from the tire weight distribution data, and outputting the direction and magnitude of the tire unbalance. It is characterized by providing.

  The thickness distribution measuring machine includes a base that is configured so that both ends are opposed to each other, has a non-contact type displacement sensor on both ends, and is rotatable about one end, and is rotatable. One end side of the tire is inserted into the tire, the other end side of the base is positioned outside the tire, and the distance to the inner surface of the tire is measured by a displacement sensor provided on one end of the base. It is preferable that the distance to the outer surface of the tire is measured by a displacement sensor provided in the vehicle.

  Further, the tire balance adjusting method of the present invention measures the distance to the inner surface of the tire and the distance to the outer surface of the tire along the circumferential direction and the cross-sectional direction, and based on the measured distance data, the circumferential direction and the cross-sectional direction of the tire Tire thickness distribution data, tire circumferential direction and cross section direction thickness distribution data and preset specific gravity distribution data to obtain tire circumferential direction and cross section direction weight distribution data, and tire weight The position of the center of gravity of the tire is obtained from the distribution data, and the direction and magnitude of the tire unbalance are output.

  When setting the specific gravity distribution data, for the reference tire whose position of the center of gravity is known, the distance to the inner surface of the tire and the distance to the outer surface of the tire along the circumferential direction and the cross-sectional direction were measured, and the measured distance data Based on the thickness distribution data of the reference tire in the circumferential direction and the cross-sectional direction, the thickness distribution data of the reference tire in the circumferential direction and the cross-sectional direction and the specific gravity distribution data set temporarily are used. Is obtained from the weight distribution data of the reference tire, the position of the center of gravity of the reference tire is obtained from the weight distribution data of the reference tire, and the position of the center of gravity of the reference tire calculated from the set specific gravity distribution data is calculated from the known position of the center of gravity of the reference tire. It is preferable to set by modifying the specific gravity distribution data set so as to be within the predetermined allowable range.

  The present invention determines the positions of the lightest and heaviest parts of the tire including not only the circumferential direction of the tire but also the cross-sectional direction from the tire thickness distribution and the tire weight distribution, as well as the position of the center of gravity of the tire. Can be used to improve the tire balance.

  Next, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the tire balance device of the present invention calculates a thickness distribution measuring machine 1 that measures the distance to the inner surface and the outer surface of the tire, and distance data obtained by the thickness distribution measuring machine 1. The distance data processing device 12 calculates the thickness and weight of each portion of the tire and obtains the tire thickness distribution, weight distribution, and center of gravity.

  First, the thickness distribution measuring machine 1 will be described. FIG. 2 is a diagram illustrating an example of the thickness distribution measuring machine 1. As shown in FIG. 2, the thickness distribution measuring machine 1 includes a support 3 on one end 2 a side of the base 2, and the support base 3 is irradiated with a laser beam toward the other end 2 b of the base 2. A non-contact type laser displacement sensor 5 provided with a non-contact type laser displacement sensor 5 attached to the other end 2b of the base 2 so as to irradiate the laser beam toward the one end 2a of the base 2 5 is provided. In addition, the thickness distribution measuring machine 1 is attached to a support arm 6 and can freely rotate around the rotation shaft 4 of the support base 3.

  FIG. 3 is a diagram illustrating a state in which the thickness distribution measuring machine is measuring the thickness of the bead portion T1 of the tire T. The tire T is attached to the rotating machine 7 and is rotatable. When measuring the thickness of the bead portion T1 of the tire T, the position of the rotating shaft 4 of the support base 3 that supports the laser displacement sensor 5 is equal from the bead portions on both sides of the tire T, and the tread of the tire T is measured. The support arm 6 is inserted into the tire T so that the base 2 is not in contact with the bead portion T1 of the tire T when the thickness of the portion (center portion of the tire) T3 is measured, and the support arm 6 is fixed. . And while rotating the tire T with the rotating machine 7, the distance D1 to the inner surface of the bead portion T1 is measured by the laser displacement sensor 5 provided on the one end 2a side of the base body 2, and provided on the other end 2b side of the base body 2 The measured laser displacement sensor 5 measures the distance D4 to the outer surface of the bead portion T1. Since the distance D5 between the laser displacement sensors 5 and 5 is known, the thickness D of the bead portion T1 of the tire T is known by D5- (D1 + D4).

  FIG. 4 is a diagram showing a state when the thickness distribution measuring instrument is measuring the thickness of the shoulder T2 of the tire T. FIG. 5 is a diagram illustrating a state in which the thickness distribution measuring machine is measuring the thickness of the tread portion (the center portion of the tire) T3 of the tire T. As shown in FIGS. 4 and 5, the thickness distribution measuring machine rotates so that the position of the laser displacement sensor 5 on the other end 2b side of the base 2 is the position of the shoulder portion T2 and the tread portion T3 of the tire. By rotating about the shaft 4, the distance to the inner surface of the tire and the distance to the outer surface of the tire in the shoulder portion T2 and the tread portion T3 can be measured.

  As described above, the thickness distribution measuring machine rotates the thickness distribution measuring machine in the tire cross-sectional direction around the rotation shaft 4, so that the inner surface of the tire extends from one bead portion in the cross-sectional direction of the tire T to the tread portion. And the distance to the outer surface of the tire can be measured. Further, the tire T is inverted and attached to the rotating machine 7, and the distance from the other bead portion in the cross-sectional direction of the tire T to the inner surface of the tire and the distance to the outer surface of the tire are measured. The distance to the inner surface of the tire and the distance to the outer surface of the tire can be measured over the entire cross-sectional direction.

  Moreover, in this thickness distribution measuring machine, by measuring while rotating the tire T with the rotating machine 7, the distance to the inner surface of the tire over the entire circumferential direction of the tire T and the tire for a predetermined portion in the cross-sectional direction of the tire T The distance to the outer surface of can be measured.

  Next, the distance data processing device 12 shown in FIG. 1 will be described. As shown in FIG. 1, the distance data processing device 12 includes a thickness calculator 13, a weight calculator 14, an image processor 15, and a display unit 16. The data of the distances D1 and D4 obtained by the laser displacement sensors 5 and 5 are input as data signals to the thickness calculator 13 of the distance data processing device 12 realized by software control using a computer, and the thickness calculation is performed. In section 13, the calculation of D5- (D1 + D4) is performed to calculate the tire thickness D.

  Further, from the distance data from the laser displacement sensors 5 and 5 obtained while rotating the thickness distribution measuring machine around the rotating shaft 4 in the tire cross-sectional direction, the thickness calculating unit 13 performs the above-described process. The tire thickness is calculated, and the thickness distribution data in the tire cross-sectional direction is obtained. Further, the thickness distribution in the cross-sectional direction of the tire is displayed on the display unit 16 via the image processing unit 15.

  FIG. 6 is a diagram for explaining a cross-sectional direction, a thickness direction, and a circumferential direction of the tire. The cross-sectional direction of the tire is the X direction, the thickness direction of the tire is the Y direction, and the circumferential direction of the tire is the Z direction. FIG. 7 is a diagram illustrating an example of the thickness distribution in the tire cross-sectional direction (X direction) at a certain angular position in the circumferential direction of the tire.

  Further, the tire thickness is calculated by the thickness calculator 13 as described above while rotating the tire T by the rotating machine 7, and the tire thickness distribution data is obtained. Further, the tire thickness distribution in the circumferential direction is displayed on the display unit 16 via the image processing unit 15. FIG. 8 is a diagram showing an example of the thickness distribution in the circumferential direction (Z direction) of the tire obtained as described above while rotating the tire T with the rotating machine 7 at a position in the tire cross-sectional direction. .

  Further, if necessary, in order to make the tire thickness distribution more visually understandable, the image processing unit 15 uses the tire cross-sectional thickness distribution data and the tire circumferential thickness distribution data. Are two-dimensionally processed, and a two-dimensional distribution of tire thickness is displayed on the display unit 16. FIG. 9 is a diagram showing the tire thickness as a two-dimensional distribution in the cross-sectional direction (X direction) and the circumferential direction (Z direction), where the tire thickness direction is the Y direction.

  Next, the weight calculator 14 obtains weight distribution in the circumferential direction and the cross-sectional direction of the tire. The tire weight distribution is obtained as follows. As shown in FIG. 10, the x-axis and y-axis are taken so as to pass through the center axis of the tire, the position in the circumferential direction of the tire T is represented by θ with reference to the x-axis, and the tire T is a minute portion in the circumferential direction. Further, as shown in FIG. 11, the x-axis and the y-axis are taken so as to pass through the rotating shaft 4 of the tire thickness measuring machine 1, and the tire is referenced to the x-axis. The position of T in the cross-sectional direction is represented by ψ, the tire is divided into minute portions dψ in the cross-sectional direction, the specific gravity per unit thickness set in advance at the position of the minute portion, and the thickness calculated as described above. The weight at this position is obtained by the product of.

  In this way, the weight is calculated for each minute portion dψ in the tire cross-sectional direction based on the thickness distribution data in the tire circumferential direction and the specific gravity distribution data set in advance, and the weight distribution data in the tire cross-sectional direction. Can be requested. Further, at an arbitrary position of ψ, the weight is calculated for each minute portion dθ in the circumferential direction of the tire based on the thickness distribution data in the tire cross-sectional direction and the specific gravity distribution data set in advance. Can be obtained.

  Further, the weight distribution in the cross-sectional direction of the tire and the weight distribution in the circumferential direction of the tire obtained as described above are displayed on the display unit 16 via the image processing unit 15. Further, if necessary, in order to make the weight distribution of the tire more visually understandable, the image processing unit 15 uses the weight distribution data in the tire cross-sectional direction and the weight distribution data in the circumferential direction of the tire. Are displayed on the display unit 16 in a two-dimensional distribution in the cross-sectional direction (X direction) and the circumferential direction (Z direction).

  Further, the weight calculation unit 14 obtains a moment about the x-axis from the weight for each minute portion dθdψ divided in the circumferential direction and the cross-sectional direction and the distance from the x-axis, and further, the fine portion divided in the circumferential direction and the cross-sectional direction. The moment about the y-axis is obtained from the weight for each dθdψ and the distance from the y-axis, and the moment around the x-axis and the moment about the y-axis are combined to obtain the position of the center of gravity of the tire. Further, the direction and size of the center of gravity position of the tire are displayed on the display unit 16.

  Based on the tire thickness distribution, the tire weight distribution, and the center of gravity position of the tire displayed on the display section 16, the circumferential direction and the cross-sectional direction of the lightest and heaviest part of the tire that is the unbalanced position of the tire Can be determined.

  Next, a method for obtaining preset specific gravity distribution data will be described. First, for a reference tire whose position of the center of gravity is known, as described above, the distance to the inner surface of the tire and the distance to the outer surface of the tire along the circumferential direction and the cross-sectional direction are measured, and based on the measured distance data Thickness distribution data in the circumferential direction and the cross-sectional direction of the reference tire is obtained. Next, based on the thickness distribution data in the circumferential direction and the cross-sectional direction of the reference tire and the specific gravity distribution data set temporarily, the weight distribution data in the circumferential direction and the cross-sectional direction of the tire are obtained, and from the weight distribution data of the reference tire As described above, the positions of the center of gravity of the reference tire are obtained by synthesizing moments about the x-axis and the y-axis.

  Compare the position of the center of gravity of the reference tire calculated from the specific gravity distribution data set to the known position of the center of gravity of the reference tire, and the position of the center of gravity of the reference tire calculated from the specific gravity distribution data set temporarily If it is not within the predetermined allowable range from the known position of the center of gravity of the tire, the value of the specific gravity distribution data is changed, the tire weight distribution data is obtained again as described above, and the position of the center of gravity of the tire is further obtained. . When the position of the center of gravity of the reference tire calculated from the changed specific gravity distribution data falls within a predetermined allowable range from the position of the known center of gravity of the reference tire, the changed specific gravity distribution data is determined. In this way, preset specific gravity distribution data can be obtained.

  As described above, the present invention is based on the tire thickness distribution and the tire weight distribution, and further, based on the position of the center of gravity of the tire, the lightest portion of the tire including not only the tire circumferential direction but also the cross-sectional direction, The position of the heavy part can be obtained, which can be used to improve the tire balance.

It is a lineblock diagram of the tire balance device of the present invention. It is a figure which shows an example of a thickness distribution measuring machine. It is a figure which shows a state when the thickness distribution measuring machine is measuring the thickness of the bead part of a tire. It is a figure which shows a state when the thickness distribution measuring machine is measuring the thickness of the shoulder part of a tire. It is a figure which shows a state when the thickness distribution measuring machine is measuring the thickness of the tread part of a tire. It is a figure explaining the section direction, thickness direction, and circumferential direction of a tire. It is a figure which shows an example of the thickness distribution of the cross-sectional direction of a tire. It is a figure which shows an example of the thickness distribution of the circumferential direction of a tire. It is a figure which shows three-dimensional distribution of the thickness of a tire. It is a top view of a tire. It is sectional drawing of a tire. It is sectional drawing of a static balance measuring apparatus. It is a top view of a static balance measuring device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thickness distribution measuring machine 2 Base | substrate 3 Support stand 4 Rotating shaft 5 Laser displacement sensor 6 Support arm 7 Rotating machine 12 Distance data processing device 13 Thickness calculating part 14 Weight calculating part 15 Image processing part 16 Display part 16 Static balance measurement Equipment 21, 22, 23, 24 Load cell 26 Weighing table 28 Main body T Tire T1 Bead part T2 Shoulder part T3 Tread part

Claims (4)

A thickness distribution measuring machine for measuring the distance to the inner surface of the tire and the distance to the outer surface of the tire along the circumferential direction and the cross-sectional direction;
Based on the distance data from the thickness distribution measuring device, the tire thickness distribution data in the circumferential direction and the cross-sectional direction is obtained, and the thickness distribution data in the tire circumferential direction and the cross-sectional direction and the preset specific gravity distribution data are obtained. Based on the weight distribution data of the tire in the circumferential direction and the cross-sectional direction, the weight distribution data is output, and the center of gravity of the tire is determined from the tire weight distribution data, and the direction and magnitude of the tire unbalance are output. A distance data processing device,
A tire balance device comprising:   The thickness distribution measuring device includes a base that is configured so that both ends are opposed to each other, has a non-contact type displacement sensor on both ends, and is rotatable about one end, and is rotatable. One end side of the tire is inserted into the tire, the other end side of the base is positioned outside the tire, and the distance to the inner surface of the tire is measured by a displacement sensor provided on one end of the base. The tire balance device according to claim 1, wherein a distance to the outer surface of the tire is measured by a displacement sensor provided in the tire. Measure the distance to the inner surface of the tire and the distance to the outer surface of the tire along the circumferential direction and the cross-sectional direction,
Based on the measured distance data, thickness distribution data in the circumferential direction and the cross-sectional direction of the tire is obtained,
Based on the thickness distribution data in the circumferential direction and the cross-sectional direction of the tire and the specific gravity distribution data set in advance, the weight distribution data in the circumferential direction and the cross-sectional direction of the tire are obtained,
A tire balance adjusting method comprising: obtaining a position of a center of gravity of a tire from tire weight distribution data, and outputting a direction and a magnitude of tire unbalance. In setting the specific gravity distribution data,
For a reference tire whose position of the center of gravity is known, measure the distance to the inner surface of the tire and the distance to the outer surface of the tire along the circumferential direction and the cross-sectional direction,
Based on the measured distance data, the thickness distribution data in the circumferential direction and the cross-sectional direction of the reference tire are obtained,
Based on the thickness distribution data in the circumferential direction and the cross-sectional direction of the reference tire and the specific gravity distribution data set temporarily, the weight distribution data in the circumferential direction and the cross-sectional direction of the tire are obtained,
Find the position of the center of gravity of the reference tire from the weight distribution data of the reference tire,
Set by correcting the set specific gravity distribution data so that the position of the center of gravity of the reference tire calculated from the set specific gravity distribution data is within a predetermined allowable range from the known position of the center of gravity of the reference tire. The tire balance adjusting method according to claim 3.

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