JP6366137B2 - Method for evaluating tire rolling resistance - Google Patents

Description

  The present invention relates to a method for evaluating tire rolling resistance. More specifically, the present invention relates to a method for evaluating the temperature dependence of tire rolling resistance.

  In recent years, the demand for lower fuel consumption of vehicles has become particularly strong due to environmental considerations. In order to achieve low fuel consumption with tires, it is important to reduce tire rolling resistance. Various properties such as hardness, elongation, and strength of rubber constituting the tire vary depending on the temperature. Tire rolling resistance also varies with temperature. It is required to accurately measure the rolling resistance of a tire including fluctuation due to temperature.

A method for measuring rolling resistance is defined in ISO 28580. According to this rule, the rolling resistance of the tire is measured at an ambient temperature of 20 ° C. or higher and 30 ° C. or lower. The measured value at an ambient temperature of 25 ° C. is the rolling resistance F _{r25 at} 25 ° C. The rolling resistance F _r at an atmospheric temperature t _amb other than 25 ° C. is calculated using the following temperature correction formula.
F _r25 = F _r × {1 + k _t × (t _amb −25)}
In this equation, _kt is a temperature correction coefficient and takes the following values.
k _t = 0.008 (° C. ⁻¹ ): In the case of a tire for passenger cars = 0.010 (° C. ⁻¹ ): In the case of a tire for trucks and buses (LI ≦ 121) = 0.006 (° C. ⁻¹ ) : For truck and bus tires (LI ≧ 122) In the above formula, LI is a tire road index. The road index LI is a symbol representing the maximum mass that can be loaded on the tire under the use conditions defined by the JATMA standard.

  Japanese Patent Application Laid-Open No. 2014-66608 discloses an apparatus for measuring the temperature dependence of tire performance. This apparatus includes a drum and an air conditioner that adjusts the temperature of the drum. With this apparatus, it is said that the temperature dependence of rolling resistance can also be measured.

JP 2014-66608 A

  Furthermore, there is a strong demand for measuring the temperature dependency of rolling resistance accurately. In order to measure the temperature dependence of rolling resistance, a method using a dedicated rolling resistance tester compliant with ISO28580 and a method using a general-purpose drum type tester for measuring various characteristics of tires are considered. . The dedicated rolling resistance tester has a narrow range of atmospheric temperatures at which rolling resistance can be measured with high accuracy. For example, it is difficult to accurately measure rolling resistance at an ambient temperature lower than 20 ° C. On the other hand, a general-purpose drum type testing machine has a wide operable temperature range. However, a general-purpose drum type testing machine cannot satisfy the rolling resistance measurement accuracy (error ± 1.0 N or less) required by ISO 28580. In order to develop a new device capable of measuring rolling resistance with high accuracy in a wide temperature range, a large cost and time are required.

  An object of the present invention is to provide an evaluation method for accurately measuring the temperature dependence of rolling resistance using existing equipment.

The method for evaluating the temperature dependence of the rolling resistance of the tire according to the present invention is as follows:
(1) A step of measuring a tire temperature Tt when the tire is in an equilibrium state by rolling the tire with a drum type tester in an environment of a constant atmospheric temperature Ta (2) Step of cooling to temperature Ti equal to or lower than Tt (3) For the cooled tire, temperature measurement and rolling resistance measurement by a rolling resistance tester are continuously performed in time series, so that the tire temperature and rolling resistance are (4) From the relationship between the temperature of the tire obtained in the step (3) and the rolling resistance, the rolling resistance at the temperature Tt is obtained, and the value of the rolling resistance is determined as the ambient temperature Ta. A step of setting the rolling resistance to a value when the tire is rolled in the environment.

  Preferably, the temperature Ti is not more than 10 ° C. lower than the temperature Tt and not less than the glass transition temperature of rubber used in the tire.

  Preferably, the temperature of the atmosphere when measuring the rolling resistance in the step (3) is 20 ° C. or higher and 30 ° C. or lower, and the humidity of this atmosphere is 60% or lower.

  Preferably, when measuring the temperature of the tire in the step (3), the temperature is measured at a plurality of locations on the tire, and the average temperature of these is the tire temperature.

  Preferably, the temperature is measured at at least one place on the tread surface, groove bottom, sidewall surface, inner surface and inside of the tire.

  An apparatus for evaluating the temperature dependency of rolling resistance of a tire according to the present invention includes a drum type tester that can be operated in a predetermined atmospheric temperature, a cooler that cools the tire, and a rolling resistance test that measures the rolling resistance of the tire. And a temperature measuring device for measuring the temperature of the tire. In this apparatus, a tire is rolled by the drum-type testing machine in an environment of a constant atmospheric temperature Ta, and the temperature Tt of the tire when the tire is in an equilibrium state is measured. The tire is cooled to a temperature Ti that is equal to or lower than the temperature Tt in the cooler. The relationship between the temperature of the tire and the rolling resistance is measured by continuously performing temperature measurement by the temperature measuring device and rolling resistance measurement by the rolling resistance tester in time series. From the relationship between the temperature of the tire and the rolling resistance, the rolling resistance at the temperature Tt is obtained, and the value of the rolling resistance is the value of the rolling resistance when the tire is rolled in the environment of the ambient temperature Ta. .

  In the method for measuring rolling resistance according to the present invention, first, a tire is rolled by a drum type tester in an environment of a predetermined atmospheric temperature Ta, and the temperature Tt of the tire when the tire is in an equilibrium state is measured. The Next, the tire is cooled to a temperature equal to or lower than the temperature Tt. For this tire, temperature measurement and rolling resistance measurement by a rolling resistance tester are continuously performed in time series. During the measurement, the temperature of the cooled tire gradually increases. Thereby, the relationship between tire temperature and rolling resistance is measured. The rolling resistance at the tire temperature Tt is obtained. The value of this rolling resistance is the rolling resistance when the tire is rolled in the environment of the ambient temperature Ta. According to this method, in order to obtain the rolling resistance at the atmospheric temperature Ta, it is not necessary to set the atmospheric temperature at which the rolling resistance tester is operated to the temperature Ta. The rolling resistance tester can be operated at an ambient temperature at which it can operate accurately. The rolling resistance at the atmospheric temperature Ta can be measured while operating the rolling resistance tester at an atmospheric temperature at which the rolling resistance testing machine can be operated with high accuracy. According to this method, the temperature dependency of the rolling resistance can be measured with high accuracy.

FIG. 1 is a graph showing changes in tire temperature over time when a tire is rolled in a constant ambient temperature environment in the method for measuring the temperature dependence of rolling resistance according to an embodiment of the present invention. It is. FIG. 2 is a schematic diagram showing a state in which the rolling resistance is measured in the method for measuring the temperature dependence of the rolling resistance according to the embodiment of the present invention. FIG. 3 is a graph showing changes with time in the tire temperature and the rolling resistance coefficient obtained by the measurement in FIG. 2. FIG. 4 is a graph showing the relationship between the rolling resistance coefficient and the tire temperature in FIG. FIG. 5 is a graph showing a change in tire temperature over time when the tire is rolled in an environment having a constant ambient temperature, measured in an example of the present invention. FIG. 6 is a diagram showing the change over time of the rolling resistance coefficient measured in the example of the present invention. FIG. 7 is a graph showing changes with time in the tire temperature measured in the example of the present invention. FIG. 8 is a graph showing the relationship between the rolling resistance coefficient of FIG. 6 and the tire temperature of FIG.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings. In the following embodiment, the rolling resistance coefficient of the tire at the atmospheric temperature Ta is measured. The ambient temperature Ta is a temperature lower than the lower limit temperature at which the rolling resistance tester can operate with high accuracy.

The method for measuring the temperature dependence of the rolling resistance according to the present invention is as follows:
(1) A step of measuring the tire temperature when the tire is rolled and brought into an equilibrium state in an environment having an atmospheric temperature Ta,
(2) a step of cooling the tire,
(3) measuring the relationship between rolling resistance and tire temperature;
And (4) a step of obtaining a value of rolling resistance when the tire is rolled in an environment having an atmospheric temperature Ta.

  In the step (1), the tire is first assembled into the rim. The tire is filled with air. In this step, a general-purpose drum type tester (not shown) is used. The temperature of the room in which the drum type testing machine is installed is kept at a constant temperature Ta. The atmospheric temperature of the drum type tester is kept at a constant temperature Ta. The temperature Ta is an ambient temperature at which rolling resistance is to be measured. As described above, the ambient temperature Ta is at least lower than the lower limit temperature at which the rolling resistance tester can operate with high accuracy. The ambient temperature Ta is a temperature within a range where the drum type testing machine can operate normally. A temperature sensor is attached to the tire. The tire is held in this environment until the temperature Ta is reached. The tire is then set on a drum type testing machine. The outer peripheral surface of the drum of the testing machine is brought into contact with the tread surface of the tire. A constant load is applied to the tire toward the drum. This load is the same as the load Fz applied to the tire by a rolling resistance tester described later. The drum rotates at a constant speed. Along with this, the tire rolls at a constant speed. This rolling speed is the same as the speed V at which the tire rolls with a rolling resistance tester to be described later.

  The tire is rolled and the tire temperature is continuously measured in time series. An example of the measurement result is shown in FIG. As shown in the figure, as time elapses, the temperature of the tire rises due to heat generated by rolling. This rate of increase gradually decreases. Eventually this tire will be in equilibrium. At this time, the tire has a constant temperature Tt. In this drawing, it is shown that when the tire is rolled at a speed V with the load Fz applied in the environment of the ambient temperature Ta, the tire temperature becomes Tt in the tire equilibrium state.

  In the step (2), the tire is placed in a refrigerator. The tire is cooled until the entire tire reaches a temperature Ti equal to or lower than the temperature Tt. The temperature Ti is an initial temperature of the tire when the rolling resistance is measured in the following step (3). The temperature Ti is a lower limit value of the tire temperature in the relationship between the tire temperature measured in the step (3) and the rolling resistance.

  In the step (3), the tire cooled in the step (2) is mounted on a dedicated rolling resistance tester compliant with ISO28580. The atmospheric temperature at this time is set to a temperature at which the rolling resistance tester can operate with high accuracy. This temperature is usually around 25 ° C. A temperature sensor is attached to the tire. This temperature sensor can record the temperature of a tire at a constant time interval.

  FIG. 2 is a schematic diagram showing a state in which the rolling resistance is measured with a rolling resistance tester. The rolling resistance tester includes a drum 2. The outer peripheral surface 4 of the drum 2 and the tread surface of the tire 6 are brought into contact with each other. A constant load Fz is applied to the tire 6 toward the drum 2. The drum 2 rotates around the rotation axis O in the direction of arrow A at a constant speed. Accordingly, the tire 6 also rolls in the direction of arrow B at a constant speed V. A force Fx acting in the rotational direction on the tread surface of the tire 6 is measured. This force Fx is rolling resistance. With this rolling resistance tester, the rolling resistance can be measured with an accuracy of an error of ± 0.5 N or less. A value (Fx / Fz) obtained by dividing the rolling resistance Fx by the load Fz is a rolling resistance coefficient. In this specification, all measurement results are expressed as rolling resistance coefficients.

  The tire 6 is rolled, and the temperature of the tire 6 and the rolling resistance coefficient of the tire 6 are continuously measured in time series. An example of the measurement result is shown in FIG. In this figure, the time change of the tire 6 temperature and the rolling resistance coefficient is shown. As described above, the temperature of the tire 6 when the measurement is started is the initial temperature Ti. As shown in the figure, as time elapses, the temperature of the tire 6 gradually increases due to heat transmitted from the atmosphere and heat generated by rolling. As the temperature of the tire 6 increases, the rolling resistance coefficient decreases. FIG. 4 shows the result of plotting the relationship between the tire temperature and the rolling resistance coefficient. In this figure, the horizontal axis represents the tire temperature, and the vertical axis represents the rolling resistance coefficient at that temperature. By this method, the relationship between the tire temperature and the rolling resistance coefficient is measured. By this method, the tire temperature dependence of rolling resistance is measured.

  In the step (4), the rolling resistance coefficient at the tire temperature Tt measured in the step (1) is obtained from the relationship between the tire temperature measured in the above (3) and the rolling resistance coefficient. FIG. 4 shows this state. In this figure, the rolling resistance coefficient of the tire temperature Tt is Ct. The rolling resistance coefficient is the rolling resistance coefficient when the tire 6 is rolled in an environment where the atmospheric temperature Ta is Ct. Thereby, the relationship between the rolling resistance coefficient and the ambient temperature is obtained. Thereby, the atmospheric temperature dependence of rolling resistance is obtained.

  Hereinafter, the function and effect of the present invention will be described.

  There is a strong demand for more accurately determining the temperature dependence of rolling resistance. In a dedicated rolling resistance tester compliant with ISO28580, the range of the atmospheric temperature at which the rolling resistance can be measured with high accuracy is narrow. For example, it is difficult to accurately measure rolling resistance at an ambient temperature lower than 20 ° C. On the other hand, a general-purpose drum type testing machine has a wide operable temperature range. However, a general-purpose drum type testing machine cannot satisfy the rolling resistance measurement accuracy (error ± 1.0 N or less) required by ISO 28580.

    In the method for measuring rolling resistance according to the present invention, first, a tire is rolled by a drum type tester in an environment of a predetermined atmospheric temperature Ta, and the temperature Tt of the tire when the tire is in an equilibrium state is measured. . Next, the tire 6 is cooled to a temperature equal to or lower than the temperature Tt. For the tire 6, the temperature measurement and the measurement of the rolling resistance coefficient by a rolling resistance tester are continuously performed in time series. During the measurement, the temperature of the cooled tire 6 gradually increases. Thereby, the relationship between tire temperature and rolling resistance is measured. A rolling resistance coefficient Ct at the temperature Tt of the tire 6 is obtained. This rolling resistance coefficient Ct is set as the rolling resistance coefficient Ct when the tire 6 is rolled in the environment of the ambient temperature Ta. According to this method, in order to obtain the rolling resistance at the atmospheric temperature Ta, it is not necessary to set the atmospheric temperature at which the rolling resistance tester is operated to the temperature Ta. The rolling resistance tester can be operated at an ambient temperature at which it can operate accurately. The rolling resistance at the atmospheric temperature Ta can be measured while operating the rolling resistance tester at an atmospheric temperature at which the rolling resistance testing machine can be operated with high accuracy. According to this method, the temperature dependency of the rolling resistance can be measured with high accuracy.

  In this method, first, the temperature Tt is measured in the step (1), and the initial temperature Ti of the tire 6 is set to be equal to or lower than the temperature Tt in the step (2). By setting the initial temperature Ti to be equal to or lower than the temperature Tt, the temperature Tt can be within the temperature range measured in the step (3). The rolling resistance coefficient at the tire temperature Tt can be measured with high accuracy. Thereby, the rolling resistance coefficient when rolling the tire 6 at the atmospheric temperature Ta can be obtained with high accuracy.

  A method of carrying out step (1) after step (3) is also conceivable. In this case, when the tire 6 is cooled in (2), the temperature Tt has not been measured yet. In order to obtain the rolling resistance coefficient at the atmospheric temperature Ta with high accuracy, the temperature Tt needs to fall within the temperature range measured in the step (3). In order to make the temperature Tt fall within this temperature range, a value sufficiently smaller than the assumed temperature Tt is selected as the initial temperature Ti. As the temperature at which the measurement is finished in the step (3), a value sufficiently larger than the assumed temperature Tt is selected.

  In the method for measuring rolling resistance according to the present invention, first, the temperature Tt is measured in step (1). The initial temperature Ti can be set to a temperature lower than the temperature Tt and close to the temperature Tt. In step (3), the measurement can be terminated when the tire temperature exceeds the temperature Tt. That is, in the step (3), only the vicinity of the temperature Tt can be measured. Thereby, the measurement time of a process (3) can be shortened.

  The equipment used in this method is a general-purpose drum type tester, a dedicated rolling resistance tester compliant with ISO28580, a cooler for cooling tires, and a temperature measuring device. These are existing devices. In this method, the rolling resistance coefficient at the atmospheric temperature Ta lower than the lower limit temperature at which the rolling resistance tester can operate with high accuracy can be measured with high accuracy using existing equipment.

  The initial temperature Ti is more preferably 10 ° C. or lower than the temperature Tt. The tire 6 is cooled to the temperature Ti in the step (1). The temperature of the tire 6 may rise before the measurement of the rolling resistance coefficient is started in step (2). By setting the initial temperature Ti to 10 ° C. or lower than the temperature Tt, the temperature Tt can be included in the measurement range in the step (2). Thereby, the rolling resistance coefficient at the tire temperature Tt can be accurately measured. Thereby, the rolling resistance coefficient when rolling the tire 6 at the atmospheric temperature Ta can be obtained with high accuracy.

  The initial temperature Ti is preferably equal to or higher than the glass transition temperature Tg of the rubber used for the tire 6. By setting the initial temperature Ti to be equal to or higher than the glass transition temperature Tg, the tire 6 is prevented from being damaged by this measurement. The tire 6 maintains high quality even after the measurement.

  As described above, the ambient temperature when measuring the rolling resistance coefficient in step (3) is set to a temperature at which the rolling resistance tester can operate with high accuracy. The atmospheric temperature at this time is preferably 20 ° C. or higher and 30 ° C. or lower. By setting the atmospheric temperature to 20 ° C. or higher and 30 ° C. or lower, the rolling resistance coefficient can be accurately measured. From this viewpoint, the atmospheric temperature is more preferably 23 ° C. or higher and 27 ° C. or lower, and further preferably 25 ° C.

  The humidity of the atmosphere when measuring the rolling resistance in the step (3) is preferably 60% or less. By setting the humidity of the atmosphere to 60% or less, it is possible to suppress the condensation from adhering to the surface of the tire 6 when measuring the rolling resistance measurement coefficient. Thereby, a rolling resistance coefficient can be measured more accurately.

  When measuring the temperature of the tire 6 in the step (3), it is preferable to measure the temperature at a plurality of locations of the tire 6 and set the average of the temperatures as the temperature of the tire 6. In the step (3), the temperature of the cooled tire 6 gradually increases with time. At this time, the degree of rise of the tire 6 may vary depending on the portion of the tire 6. By measuring the temperature of the tire 6 at a plurality of locations and taking the average, the relationship between the tire temperature and the rolling resistance coefficient can be measured more accurately.

  The place where the temperature of the tire 6 is measured preferably includes at least one of the tread surface of the tire 6, the groove bottom of the tire 6, the sidewall surface of the tire 6, the inner surface of the tire 6, and the inside of the tire 6. . By including these, the relationship between the tire temperature and the rolling resistance coefficient can be measured more accurately.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Specifications of rolling resistance tester]
In this example, a rolling resistance tester compliant with ISO28580 was used. The measurement error of the rolling resistance Fx of this testing machine is ± 0.5 N or less. This satisfies the required accuracy of rolling resistance measurement specified in ISO28580. The temperature range in which this apparatus can operate with high accuracy is 18 ° C. or higher and 30 ° C. or lower. It is not possible to measure rolling resistance at an ambient temperature exceeding this temperature range with this testing machine alone.

[Specifications of drum type tester]
In this example, a general-purpose drum type tester was used. This drum type testing machine is an inside type. The operating temperature range of this testing machine is −10 ° C. or more and 40 ° or less. The measurement error of the rolling resistance Fx of this drum type tester is ± 20 N or less. This does not satisfy the required accuracy of the rolling resistance measurement specified in ISO28580. In addition, the skim load (about 100 N) that needs to be loaded in order to accurately measure the rolling resistance cannot be loaded because it is too small. With this drum type tester alone, it is impossible to measure rolling resistance that satisfies the required accuracy.

[Tire preparation]
Tires used for evaluation were prepared. The size of this tire is 195 / 65R15 91S. This tire was incorporated into a standard rim (size = 15 × 6.0). The internal pressure of this tire was 210 kPa.

[Example 1]
The temperature dependency of rolling resistance was evaluated by the method according to the present invention. First, the tire temperature Tt was measured when the tire was rolled in an environment where the ambient temperature was Ta using the drum-type testing machine and the equilibrium state was reached. The test conditions at this time are as follows.
Atmosphere temperature Ta: 0 ° C
Load: 4.82kN
Rolling speed: 80km / h

Next, the tire was cooled in a refrigerator until the initial temperature Ti became −10 ° C. The rolling resistance coefficient of the tire was measured using the above rolling resistance tester. Along with the measurement of the rolling resistance coefficient, the tire temperature was measured. The tire temperature was measured on the tread surface, tire groove bottom, sidewall surface, tire inner surface and inside the tire, and the average value was defined as the tire temperature. As a result, the relationship between the tire temperature and the rolling resistance coefficient was measured. The tire temperature dependence of rolling resistance was measured. The test conditions for measuring the rolling resistance coefficient are as follows.
Atmospheric temperature: 25 ° C
Load Fz: 4.82kN
Rolling speed V: 80 km / h

  The rolling resistance coefficient Ct at the tire temperature Tt was determined from the relationship between the tire temperature and the rolling resistance coefficient. This value was taken as the rolling resistance coefficient when the tire was rolled in an environment where the ambient temperature Ta was 0 ° C.

[Example 2]
The tire temperature Tt when the equilibrium state was reached was measured in the same manner as in Example 1 except that the atmospheric temperature Ta was set to 10 ° C. Further, the rolling resistance coefficient Ct at the tire temperature Tt was determined from the relationship between the tire temperature measured in Example 1 and the rolling resistance coefficient. This value was taken as the rolling resistance coefficient when the tire was rolled in an environment where the ambient temperature Ta was 10 ° C.

[Tire temperature at equilibrium]
FIG. 5 shows a change in the tire temperature with time when the tire is rolled in an environment of the atmospheric temperature Ta. In this figure, the case where the atmospheric temperature Ta is 0 ° C. and 10 ° C. is shown. Table 1 shows the tire temperature Tt in an equilibrium state obtained from the measurement result.

[Tire temperature dependence of rolling resistance coefficient]
The change with time of the rolling resistance coefficient measured in Example 1 is shown in FIG. FIG. 7 shows the change in tire temperature with time when measuring the rolling resistance. FIG. 8 shows the relationship between the tire temperature and the rolling resistance coefficient obtained from these measurement results. FIG. 8 shows the tire temperature dependence of the rolling resistance coefficient.

[Ambient temperature dependence of rolling resistance coefficient]
Table 1 shows the rolling resistance coefficient at the atmospheric temperature Ta obtained by the above method. Table 1 shows the atmospheric temperature dependence of the rolling resistance coefficient.

  As shown in Table 1, in the method of the example, the temperature dependency of the rolling resistance coefficient can be measured in a wide temperature range. From this evaluation result, the superiority of the present invention is clear.

  The method described above can be used for evaluating the rolling resistance of various tires.

2 ... Drum 4 ... Outer peripheral surface 6 ... Tire 8 ... Tread surface

Claims (6)

(1) A step of measuring a tire temperature Tt when the tire is in an equilibrium state by rolling the tire with a drum type tester in an environment of a constant atmospheric temperature Ta (2) Step of cooling to temperature Ti equal to or lower than Tt (3) For the cooled tire, temperature measurement and rolling resistance measurement by a rolling resistance tester are continuously performed in time series, so that the tire temperature and rolling resistance are (4) From the relationship between the temperature of the tire obtained in the step (3) and the rolling resistance, the rolling resistance at the temperature Tt is obtained, and the value of the rolling resistance is determined as the ambient temperature Ta. A method for evaluating the temperature dependency of rolling resistance of a tire, including a step of setting a rolling resistance value when the tire is rolled in the environment described above.   The method for evaluating temperature dependency of rolling resistance according to claim 1, wherein the temperature Ti is not higher than a temperature lower by 10 ° C. than the temperature Tt and not lower than a glass transition temperature of rubber used in the tire.   The temperature dependence of the rolling resistance according to claim 1 or 2, wherein the temperature of the atmosphere when measuring the rolling resistance in the step (3) is 20 ° C or higher and 30 ° C or lower, and the humidity of the atmosphere is 60% or lower. Evaluation method of sex.   When measuring the temperature of a tire at the process of said (3), temperature is measured in several places of this tire, These average temperature is made into the temperature of this tire. To evaluate the temperature dependence of rolling resistance.   The method for evaluating temperature dependency of rolling resistance according to claim 4, wherein the temperature is measured at at least one place on the tread surface, groove bottom, sidewall surface, inner surface and inside of the tire. A drum type tester that can be operated in a predetermined atmospheric temperature, a refrigerator that cools the tire, a rolling resistance tester that measures the rolling resistance of the tire, and a temperature measuring instrument that measures the temperature of the tire,
The tire is rolled with the drum-type testing machine in an environment of a constant atmospheric temperature Ta, and the temperature Tt of the tire when the tire is in an equilibrium state is measured.
The tire is cooled to the temperature Ti that is equal to or lower than the temperature Tt in the above-described refrigerator,
Measuring the temperature measurement by the temperature measuring instrument and the rolling resistance measurement by the rolling resistance tester continuously in time series to measure the relationship between the temperature of the tire and the rolling resistance,
From the relationship between the temperature of the tire and the rolling resistance, the rolling resistance at the temperature Tt is obtained, and the rolling resistance value is set as the rolling resistance value when the tire is rolled in the environment of the ambient temperature Ta. Evaluation device for temperature dependence of resistance.

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