JPH07198371A - Abnormal sound generating tire judgement method - Google Patents

Abstract

PURPOSE:To obtain the abnormal sound generating tire judgment method which increases the efficiency of the judgment operation of a tire generating an abnormal sound and which judges the tire always with good accuracy without causing an irregularity in judgment accuracy. CONSTITUTION:In an abnormal sound generating tire judgment method, uneven parts on a tread face are measured continuously along the circumferential direction of a tire, and the tire generating an abnormal sound is judged on the basis of data on the measured uneven parts. A section C for the data on the uneven parts is set in such a way that the length of the circumferential length of the tire is at a measuring interval of 80 to 100mm. A difference DELTAbetween the maximum value M and the minimum value N of the data on the uneven parts in every section is found over the whole circumference of the tire by shifting the section by one data each. When the difference DELTA is larger than a reference value even in one section, the tire is judged to be a tire generating the abnormal sound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of determining an abnormal noise-producing tire which produces an abnormal noise during running of an actual vehicle.
The present invention relates to an abnormal noise generation tire determination method that always accurately determines an abnormal noise generation tire without causing variations in determination accuracy.

[0002]

2. Description of the Related Art While a vehicle equipped with a pneumatic tire is running, an abnormal noise may be generated from the tire. Examination of such tires has revealed that the tread surface has local unevenness, which causes the abnormal noise. When finding the abnormal noise generating tire having such local unevenness, the operator visually observes and makes a determination by finding the local unevenness by the tactile sensation, but the accuracy of the determination is different for each operator. There is a problem that it is difficult to always accurately and accurately determine the abnormal noise generating tire. Further, there is a problem that it takes a long time to make a determination, the efficiency of the determination work is poor, and the worker is required to have a considerable degree of skill.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to improve the work efficiency of determining a tire that produces an abnormal noise, and to always make an accurate determination without causing variations in the determination accuracy. It is to provide a tire determination method.

[0004]

SUMMARY OF THE INVENTION To achieve the above object, the present invention continuously measures the unevenness of the tread surface along the tire circumferential direction, and determines the tire generating the abnormal noise based on the measured unevenness data. A method for determining a tire that generates abnormal noise,
The section of the unevenness data has a tire circumference of 80 to 10
The measurement interval is set to 0 mm, the section is shifted by 1 data, and the difference between the maximum value and the minimum value of the unevenness data in each section is obtained over the entire circumference of the tire, and the difference and a predetermined reference value are respectively obtained. In comparison, when the difference is larger than the reference value even in one section, the tire is determined to be an abnormal noise generating tire.

[0005]

The present invention is configured as described above and has a measurement interval of 8
It is set so as to be in the range of 0 to 100 mm, and the difference between the maximum value and the minimum value of the unevenness data in each section is calculated over the entire circumference by shifting by 1 data in the section corresponding to this setting range, and the difference Since it is determined by the above, it is possible to always determine the abnormal noise generating tire with high accuracy without being affected by the shake of the tread pattern and without causing the variation in the determination accuracy among the operators. Further, since the abnormal noise tire is determined based on the measured unevenness data, automation can be performed by the device, and the determination by the visual observation or the tactile sensation of the operator can be eliminated. It is possible to greatly improve the determination work efficiency of.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an example of an apparatus used in the method for determining a tire with abnormal noise according to the present invention. Reference numeral 1 denotes a tire mounted on a rim 2 and rotatably supported. The tire 1 rotates at a constant speed during measurement. An unevenness detection sensor (laser, differential transformer, load cell, etc.) 3 detects unevenness of the tread surface 1a of the tire 1. The unevenness detection sensor 3 outputs an analog signal corresponding to the unevenness of the tread surface 1a. The analog signal of the unevenness is input to the computing computer 8 via the amplifier 5, the low-pass filter 6.

The computing computer 8 includes an A / D converter 9, a computing unit 10, a standard determination unit 11, and a marking command unit 1.
2, the analog signal that has passed through the low-pass filter 6 is input to the arithmetic unit 10 via the A / D converter 9 as digitized irregularity data. In the arithmetic unit 10, the irregularity data in each predetermined measurement interval is input. The difference between the maximum value and the minimum value of is calculated. The standard determination unit 11
It is determined whether or not each difference data obtained by the arithmetic unit 10 is larger than a preset reference value. If the difference data is larger than the preset reference value, the control means 1 is output by the output signal of the marking instruction unit 12.
The marking device 14 is driven via 3 to mark the abnormal noise generating portion of the tire 1. The control means 13 is capable of adjusting the contact pressure of the detection roller 4 of the unevenness detection sensor 3 with respect to the tread surface 1a by an external operation and controlling the rotation of the tire 1.

In the method for determining a tire generating abnormal noise according to the present invention, first, the tread surface 1a of the tire 1 rotated at a constant speed.
The detection roller 4 is brought into contact with the center portion in the width direction of the tire at a predetermined pressure, and the unevenness state of the tread surface 1a is continuously detected by the unevenness detection sensor 3 along the tire circumferential direction. The unevenness detection sensor 3 outputs an analog signal corresponding to the unevenness state, is amplified by the amplifier 5, and is supplied to the low-pass filter 6
Then, a frequency equal to or higher than a predetermined frequency is cut and an analog signal as shown in FIG. 2 is input to the computing computer 8. In the computer 8 for calculation, it is digitized after being sampled by the A / D converter 9 at intervals of 1 msec.

The calculation unit 10 obtains the difference Δ between the maximum value M and the minimum value N of the unevenness data in the unit calculation section C where the length of the tire circumference is a measurement interval of 80 to 100 mm,
Further, the unit operation section C is shifted by 1 data corresponding to the sampling interval, and as shown in FIG. 2, while overlapping with the unit operation sections C _1, C ₂ , C _3, ...
The difference between the maximum value and the minimum value of the unevenness data in that section is calculated.

That is, the inventors of the present invention have conducted various experiments and conducted intensive studies, and as a result, the tires producing abnormal noise have a certain difference in circumferential length within a range of 80 to 100 mm. If unevenness is present, it was determined that abnormal noise would be generated from the tire when the vehicle was actually driven. If the length of the tire circumference is less than the above range, irregularities that generate abnormal noise may be overlooked, and if the length exceeds the above range, due to the influence of runout of the tread pattern, even if there are irregularities above the certain difference, It may not be the part that produces abnormal noise. Depending on the type of tire, the measurement interval has a range of 80 to 100 mm.

The difference data between the maximum value and the minimum value of the unevenness data obtained by the arithmetic unit 10 is given in advance by the standard determination unit 11 whether or not the difference exceeds the reference value of the unevenness that causes abnormal noise. By comparing with the reference data, it is determined whether or not the tire is an abnormal noise generating tire. That is, as shown in FIG. 3, if there is a local convex portion X that produces an abnormal noise on the tread surface 1a, a steep maximum value M ′ appears as shown in FIG. The difference Δ'between the maximum value M'and the minimum value N'becomes larger than a reference value at which no abnormal noise is generated within a measurement interval of 80 to 100 mm in length, and the standard determination unit 11 generates abnormal noise in the tire. It is determined to be a tire. 1
If there is a section that is larger than the reference value even in the section, it is determined that the tire is a noise generating tire.

In the calculation unit 10, the unit calculation section C is shifted by one data corresponding to the sampling interval and overlapped over the entire circumference, and the standard judgment unit 11 judges it. The part X does not become the boundary of the calculation section, and the difference between the maximum value and the minimum value of the maximum amplitude, which becomes the irregularities that generate abnormal noise, is not obtained. When the standard determination unit 11 determines that the tire 1 exceeds the reference value and is an abnormal noise generation tire, the marking command unit 12 causes the maximum value M ′ of the unevenness data in the unit calculation section having a difference exceeding the reference value. Is determined to be an abnormal noise generating section, and the control means 13
The abnormal noise generating portion of the tire 1 is stopped at a position corresponding to the marking device 14, and the marking device 14 is operated to set the sidewall portion of the tire 1 corresponding to the convex portion X which is the abnormal noise generating portion of the tread surface 1a. Mark it.

As described above, according to the present invention, the unevenness data of the tread surface 1a is measured in the section corresponding to the measurement interval of 80 to 100 mm.
By shifting each data, the difference Δ between the maximum value M and the minimum value N of the unevenness data in each section is obtained over the entire circumference of the tire,
When the difference Δ is larger than the predetermined reference value even in one section, the tire is determined to be an abnormal noise generation tire, so there is no influence of tread pattern runout, and there is no variation in determination by each operator. Therefore, it is possible to always accurately and accurately determine the tire with abnormal noise. Also, since the abnormal noise tire is determined based on the measured unevenness data, it can be automated by a device, and the determination by the operator's visual observation and tactile sensation is eliminated to shorten the determination time and determine the abnormal noise tire. The efficiency can be greatly increased.

In the present invention, in the above-described embodiment, the laser roller 4 or the sled-shaped detector may be used as the detector. Further, the low-pass filter 6 may be in a range that does not cut the irregularities that generate abnormal noise, and for example, a filter that passes low frequencies up to about 30 Hz is preferably used. Further, the sampling interval is not particularly limited as long as it is a range in which irregularities that generate abnormal noise can be picked up. For example, as described above, the sampling interval can be 1 msec.

[0015]

As described above, according to the present invention, the interval of the unevenness data is set to the measurement interval of the tire circumference of 80 to 100 mm, and the interval is shifted by one data, and the unevenness data in each interval is obtained. The difference between the maximum value and the minimum value of is calculated over the entire circumference of the tire, and if the difference is larger than the predetermined reference value even in one section, the tire is determined to be an abnormal noise, so the influence of the tread pattern deflection It is possible to always determine the abnormal noise generating tire with high accuracy without causing variations in determination accuracy, and to determine the abnormal noise generating tire based on the measured unevenness data, so automation can be performed by the device, and abnormal noise is generated. The efficiency of tire judgment work can be greatly improved.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram showing an example of an apparatus used in a method for determining a tire with abnormal noise according to the present invention.

FIG. 2 is a waveform diagram of the circumference of one rotation of a tire of an analog signal of unevenness that has passed through a low pass filter.

FIG. 3 is a main-portion cross-sectional view showing an example of a convex portion that generates abnormal noise on the tread surface.

[Explanation of symbols]

1 tire 1a tread surface 3 unevenness detection sensor 8 computing computer 9 A / D converter 10 computing unit 11 standard determination unit 12 marking command unit C section M maximum value N minimum value Δ difference

Claims (2)

[Claims] 1. An abnormal noise generation tire determination method for continuously measuring irregularities of a tread surface along a tire circumferential direction, and determining a tire generating an abnormal noise based on the measured irregularity data. The section of the tire circumference is 80 to 10
The measurement interval is set to 0 mm, the section is shifted by 1 data, and the difference between the maximum value and the minimum value of the unevenness data in each section is obtained over the entire circumference of the tire, and the difference and a predetermined reference value are respectively obtained. If the difference is larger than the reference value even in one section, the tire is determined to be the abnormal noise tire determination method. 2. A noise generation tire determination method in which, when it is determined that the tire is a noise generation tire, the maximum value of the unevenness data in the section having a difference exceeding a reference value is used as the noise generation portion. .