JP2004037286A - Indoor tire durability testing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indoor tire durability testing method capable of reproducing and accurately evaluating tire failures on the market, using an indoor tire durability machine. <P>SOLUTION: By measuring tire's inner temperature for an arbitrary tire at in-vehicle commercial running and then making a tire T actually having the same structure with the above tire running on a condition equivalent to the speed loading condition at the commercial running using an indoor tire durability testing machine, the method conducts a tire durability test under a condition with the tire's inner temperature at the indoor test meeting that at the commercial running by decreasing the testing temperature in a temperature-controlled room 2 at that time even to a temperature below that at the commercial running. <P>COPYRIGHT: (C)2004,JPO

Description

（３）室内試験（本試験）
試験タイヤを室内タイヤ耐久試験機に装着し、空気圧７００ｋＰａ、荷重２５００ｋｇの条件で、種々異なる速度で室内試験を行い、２時間走行後のタイヤ内部温度（タイヤ内部に充填された空気の温度）を計測し、その結果を表２に示した。このとき、試験室温を仮試験で得られた温度差に基づいて試験速度毎に異ならせた。そして、市場走行時のタイヤ内部温度と室内タイヤ耐久試験機を用いた本試験でのタイヤ内部温度との温度差を求め、これを表２に併せて示した。
【００２５】
【表２】

この表２から判るように、室内タイヤ耐久試験機を用いた本試験で得られたタイヤ内部温度は、実車による市場走行時のタイヤ内部温度と略同じであった。従って、市場でのタイヤ故障を精度良く再現可能であることが明らかである。
【００２６】
なお、室内試験時のタイヤ内部温度を実車による市場走行時のタイヤ内部温度に更に正確に合わせるために、表１に示す温度差をそのまま室温から減じるのではなく、両者のタイヤ内部温度がより正確に一致するような室温を選択することが望ましい。
【００２７】
【発明の効果】
以上説明したように本発明によれば、任意のタイヤについて実車による市場走行時のタイヤ内部温度を計測し、その後、室内タイヤ耐久試験機を用いて上記タイヤと実質的に同一構造を有するタイヤを市場走行時の速度荷重条件に相当する条件で走行させ、この時の試験室温を市場走行時の気温よりも下げることによって、室内試験時のタイヤ内部温度を市場走行時のタイヤ内部温度に合わせた状態でタイヤ耐久試験を実施するから、室内タイヤ耐久試験機を用いて市場でのタイヤ故障を精度良く再現して評価することができる。
【図面の簡単な説明】
【図１】本発明の室内タイヤ耐久試験方法を実施するための室内タイヤ耐久試験機を示す側面図である。
【符号の説明】
１　空調装置
２　恒温室
３　支持台
４　モータ
５　ベルト
６　ドラム
７　台車
８　重量体
９　試験荷重負荷部
１０　冷風供給装置
Ｔ　タイヤ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an indoor tire endurance test method, and more particularly, to an indoor tire endurance test method that makes it possible to accurately reproduce and evaluate a tire failure in a market using an indoor tire endurance tester.
[0002]
[Prior art]
Conventionally, when performing a tire durability test using an indoor tire durability tester, the test room temperature is kept constant, but the running environment of the test room differs greatly in the air cooling effect compared to the running environment in the market Therefore, the internal temperature of the tire particularly under high-speed running conditions is significantly different from the market.
[0003]
In contrast, tire failure in the market is often caused by a combination of a mechanical destruction factor and a thermal destruction factor due to an increase in internal temperature. Therefore, when reproducing a tire failure in the market using an indoor tire durability tester, it is an obstacle that the internal temperature of the tire at the time of the indoor test is higher than the internal temperature of the tire at the time of driving in the market. There was a problem that it could not be reproduced well.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide an indoor tire durability test method which makes it possible to accurately reproduce and evaluate a tire failure in a market using an indoor tire durability test machine.
[0005]
[Means for Solving the Problems]
The indoor tire durability test method of the present invention for achieving the above object measures the internal temperature of the tire at the time of running the market with an actual vehicle for an arbitrary tire, and then, substantially using the indoor tire durability tester and the tire The tire having the same structure is run under the conditions corresponding to the speed load condition during market running, and the test room temperature at this time is made lower than the temperature during market running, so that the tire internal temperature during the indoor test during the market running is reduced. The tire durability test is performed in a state where the temperature is adjusted to the tire internal temperature.
[0006]
More specifically, the indoor tire durability test method of the present invention measures the tire internal temperature of a given tire when the vehicle is running on the market with an actual vehicle, and then uses an indoor tire durability tester to have substantially the same structure as the tire. A tire having a tire is driven under the conditions corresponding to the speed load condition during the market running, and the tire internal temperature during the indoor test is measured.The measured tire internal temperature during the market running and the tire internal temperature during the indoor test are The tire endurance test shall be performed in a state where the internal temperature of the tire during the indoor test matches the internal temperature of the tire during market operation by lowering the test room temperature during the indoor test from the air temperature during the market operation based on the difference It is characterized by the following.
[0007]
In this way, the internal temperature of the tire during the indoor test is adjusted to the internal temperature of the tire during market operation by adjusting the test room temperature during the indoor test after measuring the internal temperature of the tire during market operation with the actual vehicle. Using a tire durability tester, it is possible to accurately reproduce and evaluate a tire failure in the market.
[0008]
In the present invention, if necessary, in addition to lowering the test room temperature at the time of the indoor test than the temperature at the time of driving on the market, by applying cold air controlled to a temperature lower than the test room temperature to the tires, It is preferable that the internal temperature of the tire at the time of the test is adjusted to the internal temperature of the tire during running on the market. In addition, it is preferable to use an indoor tester provided with a constant temperature room for controlling the room temperature by an air conditioner, and to perform a tire durability test in the constant temperature room.
[0009]
In order to reproduce the market driving environment, it is preferable to perform a tire durability test by giving a slip angle and a camber angle to the tire at the time of the indoor test. Further, it is preferable to set a plurality of driving modes for reproducing the market driving environment at the time of the indoor test, and perform the tire durability test while repeating these driving modes.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
[0011]
FIG. 1 shows an indoor tire durability tester for performing the indoor tire durability test method of the present invention. As shown in FIG. 1, the indoor tire durability tester of the present embodiment includes a constant temperature chamber 2 that controls a room temperature by an air conditioner 1. A support table 3 is provided in the constant temperature chamber 2. A motor 4, a drum 6 driven by the motor 4 via a belt 5, and a cart 7 having a tire supporting portion for rotatably supporting the tire T are mounted on the support 3. The trolley 7 is movable in a direction perpendicular to the rotation axis of the drum 6, and receives a load from a test load load unit 9 having a weight body 8 so as to press the tire T against the outer peripheral surface of the drum 6. Has become. In the vicinity of the tire T, a cool air supply device 10 that blows a cool air controlled to a temperature lower than the test room temperature on the tread surface of the tire T is arranged.
[0012]
When a tire durability test is performed using the indoor tire durability tester, a load on the tire T is set based on the weight of the weight body 8, and a running speed of the tire T is set based on the rotation speed of the motor 4. The test room temperature in the constant temperature room 2 is set by the air conditioner 1. If necessary, the cool air supply device 10 may be used to blow cool air to the tread surface of the tire T. Further, by adjusting the angle of the support shaft of the tire T, a desired slip angle and camber angle are given to the tire T.
[0013]
Next, the indoor tire durability test method of the present invention will be described. According to the present invention, prior to the indoor test, the internal temperature of each tire to be tested when the vehicle is running on the market is measured. Thereafter, a tire having substantially the same structure as that of the tire is run under the conditions corresponding to the speed load conditions during market running using an indoor tire durability tester, and the tire internal temperature during the indoor test is measured.
[0014]
Here, the market is an area where the tire is mainly used, and is classified, for example, by country or continent. In addition, the tire having substantially the same structure as the tire used during running on the market may be the tire actually used during running on the market, or may be another tire having substantially the same structure as that of the tire used during running on the market. Is also good. Note that the structure of the tire actually used at the time of running on the market may be different from the structure of the tire used for the indoor tire durability test as long as the heat generation characteristic is not substantially affected. For example, a slight change in the tread pattern has little effect on the heat generation characteristics. As the running conditions at the time of the indoor test, the speed and load during market driving may be selected as they are, but considering that the tire internal temperature is represented by a function of the product of speed and load, based on the function, By adjusting the speed and load during the indoor test, the tire durability test can be performed efficiently.
[0015]
When performing the endurance test, the test room temperature during the indoor test based on the difference between the tire internal temperature during the market run and the tire internal temperature during the indoor test measured as described above is lower than the air temperature during the market run. By lowering the tire temperature, the tire durability test is performed in a state where the temperature inside the tire at the time of the indoor test is adjusted to the temperature inside the tire during running on the market. That is, when the driving conditions are common, the tire internal temperature during the indoor test becomes higher than the tire internal temperature during the market driving, so the test room temperature during the indoor test is reduced by the rise in temperature.
[0016]
When the test room temperature at the time of the indoor test is lowered in this way, the temperature drop is reflected in the tire internal temperature, and the internal temperature of the tire at the time of the indoor test and the internal temperature of the tire at the time of running on the market substantially match. As a result, the tire failure in the market can be accurately reproduced and evaluated using the indoor tire durability tester.
[0017]
The location for measuring the internal temperature of the tire is not particularly limited, and it is sufficient to measure the temperature of the portion where durability is to be evaluated. For example, the temperature of the air filled in the tire may be used.
[0018]
As described above, in addition to lowering the test room temperature at the time of the indoor test than the temperature at the time of driving in the market, if the cold air controlled to a temperature lower than the test room temperature is applied to the tire, the tire in the market can be obtained. The failure can be reproduced with higher accuracy. In addition, if a tire durability test is performed by giving a slip angle and a camber angle to the tire during the indoor test, it is possible to reproduce the market running environment and reproduce the tire failure in the market with higher accuracy. By setting a plurality of driving modes for reproducing the market driving environment during the indoor test and performing the tire durability test while repeating these driving modes, it becomes possible to more accurately reproduce the tire failure in the market. The variation factors in the plurality of traveling modes include camber angle, slip angle, speed, and the like.For example, repetition of acceleration and deceleration, repetition of braking and driving, and repetition of straight traveling and cornering traveling are described. Just do it.
[0019]
According to the present invention, it is possible to reproduce a tire failure when traveling on a market at a specific temperature, but the market is not limited by the specific temperature. As the temperature at the time of driving in the market, it is preferable to select the season that is the harshest for the tires, that is, the average temperature in summer (July and August) in the area where use is assumed.
[0020]
In addition, the normal traveling by the actual vehicle is not strictly a constant speed, but involves acceleration, deceleration, and stopping. However, a severe condition for the tire durability performance is that the vehicle continuously runs at a substantially constant speed. Therefore, in the present invention, in order to perform the tire durability test with higher accuracy, it is desirable that the vehicle is continuously driven at a substantially constant speed in the market running by the actual vehicle.
[0021]
【Example】
The indoor tire durability test method of the present invention was performed on a pneumatic tire having a tire size of 11R22.5.
[0022]
(1) Actual vehicle test The test tire was mounted on an actual vehicle, and the vehicle was run at various speeds in the market under the conditions of air pressure 700 kPa and load 2500 kg, and the tire internal temperature after running for 2 hours (the air filled in the tire). Temperature), and the results are shown in Table 1. The temperature at the time of driving on the market was 28 ° C.
[0023]
(2) Laboratory test (temporary test)
The test tire was mounted on an indoor tire durability tester, and indoor tests were performed at various speeds under the conditions of an air pressure of 700 kPa and a load of 2500 kg, and the inside temperature of the tire after 2 hours of running (temperature of the air filled inside the tire) was measured. The measurement was performed and the results are shown in Table 1. Then, the temperature difference between the tire internal temperature during running on the market and the tire internal temperature in the provisional test using the indoor tire durability tester was determined, and this is also shown in Table 1. However, the test room temperature was 38 ° C.
[0024]
[Table 1]

(3) Laboratory test (main test)
The test tire was mounted on an indoor tire durability tester, and indoor tests were performed at various speeds under the conditions of an air pressure of 700 kPa and a load of 2500 kg, and the inside temperature of the tire after 2 hours of running (temperature of the air filled inside the tire) was measured. The measurement was performed and the results are shown in Table 2. At this time, the test room temperature was varied for each test speed based on the temperature difference obtained in the preliminary test. Then, a temperature difference between the tire internal temperature at the time of running on the market and the tire internal temperature in the present test using the indoor tire durability tester was obtained, and this is also shown in Table 2.
[0025]
[Table 2]

As can be seen from Table 2, the internal temperature of the tire obtained in this test using the indoor tire durability tester was substantially the same as the internal temperature of the tire when the vehicle was running on the market. Therefore, it is clear that a tire failure in the market can be accurately reproduced.
[0026]
In order to more accurately match the tire internal temperature at the time of the indoor test with the tire internal temperature at the time of driving on the market with an actual vehicle, the temperature difference shown in Table 1 is not directly reduced from room temperature, but both tire internal temperatures are more accurate. It is desirable to select a room temperature that matches
[0027]
【The invention's effect】
As described above, according to the present invention, a tire having substantially the same structure as the above tire is measured using an indoor tire endurance tester by measuring the internal temperature of the tire when the vehicle runs on the market with an actual vehicle for an arbitrary tire. The vehicle was run under conditions equivalent to the speed load conditions during market driving, and by lowering the test room temperature at this time than the temperature during market driving, the tire internal temperature during the indoor test was adjusted to the tire internal temperature during market driving. Since the tire durability test is performed in the state, the tire failure in the market can be accurately reproduced and evaluated using the indoor tire durability tester.
[Brief description of the drawings]
FIG. 1 is a side view showing an indoor tire durability tester for performing an indoor tire durability test method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Constant temperature room 3 Support stand 4 Motor 5 Belt 6 Drum 7 Dolly 8 Weight body 9 Test load loading part 10 Cold air supply device T Tire

Claims (6)

Measure the internal temperature of the tire at the time of running on the market with an actual vehicle for an arbitrary tire, and then use an indoor tire durability tester to apply a tire having substantially the same structure as the tire to a condition corresponding to the speed load condition at the time of running on the market. The indoor tire durability test is performed by lowering the test room temperature at this time from the temperature at the time of market driving, so that the tire internal temperature at the time of the indoor test matches the tire internal temperature at the time of market driving. Test method. Measure the internal temperature of the tire at the time of running on the market with an actual vehicle for an arbitrary tire, and then use an indoor tire durability tester to apply a tire having substantially the same structure as the tire to a condition corresponding to the speed load condition at the time of running on the market. The tire inside temperature at the time of the indoor test was measured, and the test room temperature at the time of the indoor test was measured at the time of the market operation based on the difference between the measured tire internal temperature at the time of the market drive and the tire internal temperature at the time of the indoor test. An indoor tire endurance test method in which a tire endurance test is performed in a state where the internal temperature of the tire during the indoor test is adjusted to the internal temperature of the tire during running on the market by lowering the air temperature of the tire. In addition to lowering the test room temperature during the indoor test than the market temperature during the driving, the internal temperature of the tire during the indoor testing is controlled by applying cold air to the tires at a temperature lower than the test room temperature. The indoor tire endurance test method according to claim 1 or 2, wherein the tire endurance test is performed in a state adjusted to the internal temperature of the tire at that time. The indoor tire endurance test method according to any one of claims 1 to 3, wherein a tire endurance test is performed in an indoor tire endurance tester provided with a constant temperature room whose room temperature is controlled by an air conditioner. The indoor tire durability test method according to any one of claims 1 to 4, wherein a tire endurance test is performed by giving a slip angle and a camber angle to the tire during the indoor test. The indoor tire durability test method according to any one of claims 1 to 5, wherein a plurality of travel modes for reproducing a market traveling environment are set during the indoor test, and the tire durability test is performed while repeating the travel modes.

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