JP2000346755A - Measuring method for abrasion of tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring method, for the abrasion of a tire, in which the abrasion degree of the tire can be measured objectively and precisely. SOLUTION: In this measuring method for the abrasion of a tire, a vehicle on which a reference tire Wa is mounted is run at a set speed per hour (km/h) on a test drum in an anechoic room so that a sound pressure level at every frequency in the pattern noise of the reference tire Wa can be measured in advance, and the sound pressure level at every frequency in the noise pattern of the reference tire Wa at this time is input to a data bank 3 inside a sourn- pressure-level measuring device 2. Then, a tire Wx to be measured is mounted on the vehicle, a sound-pressure level at every frequency in the pattern noise of the tire Wx, to be measured, is measured under the same condition so as to be input to the data bank 3 inside the measuring device 2. The sound pressure level, at every frequency of the tire Wa to be measured which is input to the data bank 3 inside the measuring device 2 is compared with the sound pressure level at every frequency of the reference tire Wa so as to be computed. Thereby, the abrasion amount of the tire is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring tire wear. The present invention relates to a method for measuring tire wear measured by comparing sound pressure levels for each tire.

[0002]

2. Description of the Related Art Conventionally, the measurement of the degree of wear of a tire (the degree of wear such as the amount of wear, the form of wear, the degree of uneven wear, etc.) is performed by measuring the tread grooves on the circumference of the tire W as shown in FIGS. Depth Y, step X between tread blocks, groove step Z
The wear state is determined by measuring such dimensions.

[0003]

However, in the above-described measuring method, the work of measuring the fine dimensions of the tread portion is very difficult, and when this work is performed on the circumference of the tire, it is quite troublesome. It is a laborious task,
Moreover, there is a problem that it is difficult to perform an accurate measurement.

Further, as shown in FIGS. 6A to 6G,
When a plurality of wear forms occur simultaneously in the tire circumferential direction, or as shown in FIGS. 7A to 7D, feather edge wear (a type of uneven wear in the tire circumferential direction, which is a deformation of cupping wear). When it is raised, the measurement itself of the groove depth, the step between blocks, the step of the groove, and the like is a difficult operation, and there is a problem that the measurement is difficult.

Therefore, the inventors of the present application have determined the level of the pattern noise (pitch noise) in a new tire,
It was discovered that there was a certain correlation between the level of pattern noise and the level of pattern noise in a worn tire, and the degree of wear was measured by comparing the sound pressure levels of the pattern noise of both tires with each other. It was made.

An object of the present invention is to objectively measure the degree of tire wear by comparing and calculating the sound pressure level of tire pattern noise or the sound pressure level for each frequency.
Moreover, it is an object of the present invention to provide a method for measuring tire wear, which makes it possible to accurately measure the degree of wear of the tire.

[0007]

According to the present invention, in order to achieve the above object, the sound pressure level of each frequency in the pattern noise of a reference tire is previously input to a data bank in a measuring instrument, and the pattern noise of the measured tire is measured. The gist is to measure the amount of tire wear by measuring the sound pressure level for each frequency in and comparing the sound pressure level with the sound pressure level of the reference tire input to the data bank.

Further, according to the present invention, the sound pressure level for each frequency of several types of pattern noise having different types of tire wear is previously input to a data bank in the measuring machine, and the sound pressure level for each frequency of the pattern noise of the measured tire is input. The gist of the present invention is to measure the level of tire wear by measuring the level and comparing it with the sound pressure levels of several types of pattern noise having different types of wear input to the data bank.

The present invention is constituted as described above, and has a reference sound pressure level or a sound pressure level of each pattern noise of a tire, and a sound pressure level of a pattern noise or a sound of each frequency of a measurement tire. By comparing and calculating the pressure level, the amount of wear of the tire and the form of wear of the tire can be objectively and accurately measured.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram of a method for measuring tire wear according to the present invention, and shows a test drum 1 in an anechoic chamber.
A measuring tire Wx is placed on the upper side, and a sound absorbing microphone 4 connected to a data bank 3 of a measuring device 2 for measuring a sound pressure level is installed near the measuring tire Wx. Also,
Reference numeral 5 denotes a wear amount display device connected to the measuring device 2.

The conditions at the time of measuring the pattern noise of the tire may be different depending on the type of the tire or the vehicle, but the measurement between the tires to be compared is performed under the same condition.

According to the method for measuring tire wear of the present invention, a vehicle equipped with a reference tire Wa is first installed in an anechoic chamber in order to previously measure a sound pressure level for each frequency in pattern noise of a reference tire Wa (new tire). Is run at a constant speed V (km / h) on the test drum 1, and the sound pressure level at each frequency in the pattern noise of the reference tire Wa at that time is input to the data bank 3 in the measuring device 2 and stored.

The number of reference tires Wa is not limited to one, and the sound pressure level of each pattern noise of several types of reference tires Wa can be input to the data bank 3 in the measuring device 2. .

Next, the measurement tire Wx is mounted on the vehicle,
Under the same conditions, the sound pressure level for each frequency in the pattern noise of the measurement tire Wx is measured and input to the data bank 3 in the measurement device 2, and the measurement pressure is applied to the measurement tire Wx input to the data bank 3 in the measurement device 2. The wear amount of the tire is measured by comparing and calculating the sound pressure level for each frequency of the corresponding reference tire Wa.

As a specific measuring method, the reference tire W
a and the number of pitches (N) of the measurement tire Wx on the circumference of the tire, the speed V (km / h) of the vehicle, and the dynamic load radius R (m) of the tire during traveling, the pattern noise frequency is calculated by the following equation. Is calculated.

VN / 7.2πR (Hz) For example, the frequency Pa in the pattern noise of the reference tire Wa (new tire) and the frequency Px in the pattern noise due to the cupping wear of the measurement tire Wx are as follows.
As shown in FIG. 2, the sound pressure level N ₀ at the maximum position of the difference between the sound pressure levels for each of the frequencies Pa and Px (the maximum position of the wear amount) is defined as the sound pressure level with respect to the progress of the wear amount in FIG. By converting in the conversion graph, the measured tire Wx
Can be measured for the degree of wear X (amount of wear). The measured wear degree X (wear amount) is immediately displayed on the wear amount display device 5 connected to the measuring device 2 so that the wear amount of the measured tire Wx can be grasped.

As described above, according to the present invention, the measurement tire W
By measuring the sound pressure level for each frequency in the pattern noise of x and comparing it with the sound pressure level of the reference tire Wa measured in advance, the amount of wear of the measured tire Wx can be objectively and accurately measured in physical quantities. It can be measured.

Next, as a second embodiment of the present invention,
In addition to the amount of wear measured by the above sound pressure level, the wear pattern in uneven wear in the circumferential direction of the tire (cupping wear, feather edge wear, step wear, polygonal wear, etc.)
And uneven wear in the tire width direction (single shoulder wear, double shoulder wear, center wear, medium rib wear, etc.),
In addition, local uneven wear (eccentric wear, spot wear, etc.) of the tire can be measured.

That is, the data bank 3 in the measuring instrument 2
The sound pressure level for each frequency corresponding to the type of uneven wear is input in advance, and the sound pressure level for each frequency in the pattern noise of the measurement tire Wx is measured.
As in the embodiment, the waveforms of the frequencies as shown in FIG. 2 are compared to detect the tire wear mode at the maximum value of the sound pressure level, and the degree of wear (wear amount and wear mode) of the measured tire Wx is objectively determined. In addition, it can be measured accurately and accurately.

[0021]

According to the present invention, as described above, the sound pressure level for each frequency in the pattern noise of the reference tire is previously input to the data bank in the measuring instrument, and the sound pressure level for each frequency in the pattern noise of the measured tire is obtained. Since the tire wear amount is measured by measuring the level and performing a comparison operation with the sound pressure level of the reference tire input to the data bank, the following excellent effects are obtained. . This eliminates the need for fine dimension measurement of the tire tread portion, and makes it possible to easily and accurately measure the degree of wear. . It is possible to measure relatively easily even if it was difficult to measure before, such as when multiple wear forms are combined or when feather edge wear is caused Becomes . By objectively expressing the degree of wear of the tire (amount of wear, form of wear, degree of uneven wear progress, etc.) by a new physical quantity called sound, it becomes possible to examine tire wear at a new angle.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a method for measuring tire wear embodying the present invention.

FIG. 2 is an explanatory diagram of a sound pressure level with respect to a frequency of pattern noise in a cupping wear of a tire, in which a sound pressure level of a reference tire is compared with a sound pressure level of a measurement tire.

FIG. 3 is a graph illustrating the relationship between the degree of tire wear and the sound pressure level.

FIG. 4 is an explanatory view of a conventional method for measuring wear of a measurement tire.

FIG. 5 is an explanatory view showing a worn state of a portion A in the conventional measurement tire of FIG. 4;

6 (a) to 6 (g) are explanatory views of a conventional tire wear pattern.

FIGS. 7A to 7D are explanatory diagrams showing a state of feather edge wear in a conventional tire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Test drum 2 Measuring device 3 Data bank 4 Sound absorption microphone 4 5 Abrasion amount display device Wx Measurement tire Wa Reference tire

Claims (2)

[Claims] 1. A sound pressure level for each frequency in a pattern noise of a reference tire is previously input to a data bank in a measuring device, and a sound pressure level for each frequency in a pattern noise of a measured tire is measured. A tire wear measuring method for measuring a tire wear amount by performing a comparison operation with a sound pressure level of a reference tire input to a bank. 2. A sound pressure level for each frequency of several types of pattern noise having different types of tire wear is previously input to a data bank in the measuring machine, and a sound pressure level for each frequency of the pattern noise of the measured tire is measured. A tire wear measuring method for measuring a tire wear mode by performing a comparison operation with sound pressure levels of several types of pattern noises having different wear modes input to the data bank.