JP7098510B2 - Methods, systems and programs for calculating the in-belt flexural rigidity of tires - Google Patents

Description

The present disclosure relates to methods, systems and programs for calculating the in-belt lateral bending stiffness of a tire.

The rigidity of each part related to the kinetic performance of the tire has been proposed by various physical models and used as a reference for design. Of the rigidity of each of these parts, the various rigidity of the sidewall (modal elastic modulus, axial elastic modulus, circumferential elastic modulus) can be measured by a dedicated testing machine that restrains the tread of the actual tire. However, there are various names such as tire circumferential in-belt lateral bending rigidity (tire circumferential in-plane lateral bending rigidity, belt rigidity, ring in-plane lateral bending rigidity, etc.), which are important rigidity related to tire cornering performance. There is no way to actually measure).

Japanese Patent Publication No. 2012-171467 discloses a physical theory model of a tire called a neofiara model, and describes that the transient response (dynamic tire characteristics) of the tire is evaluated. The relational expression of the theoretical model of the neofiara model is expressed by a transfer function, and is a transient with multiple sample points such as SA-CF (slip angle-cornering force) and SA-SAT (slip angle-self-aligning torque). Response data is required. In order to use this theoretical model, complicated fitting of the equation to a plurality of sample points is required, which is not easy.

Japanese Unexamined Patent Publication No. 2012-171467

The present disclosure focuses on such issues, and an object thereof is to provide a method, a system and a program for simply calculating the lateral bending rigidity in the belt surface of a tire without requiring complicated fitting. To provide.

The method of calculating the lateral bending rigidity in the belt surface of the tire of the present disclosure is
Obtained measured values of tire radius r, ground contact length L, ground contact width W, sidewall axial elastic modulus Ksy by side rigidity test, self-aligning torque SAT at a predetermined slip angle SA by cornering test, and tire lateral force Fy. Steps to take and
A step of calculating the self-aligning torque power As of the net based on the self-aligning torque SAT at the predetermined slip angle SA, and
A step of calculating the sidewall ground contact patch outer torsional rigidity Gmz based on the sidewall axial elastic modulus Ksy and the tire radius r, and
A step of calculating the gross self-aligning torque power As0 based on the net self-aligning torque power As and the sidewall grounding surface torsional rigidity Gmz.
A step of calculating the tread rubber shear rigidity Cy based on the gloss line lining torque power As0, the ground contact width W, and the ground contact length L.
A step of calculating the gloss cornering power Ky0 based on the tread rubber shear rigidity Cy, the ground contact width W, and the ground contact length L.
A step of calculating the cornering power Ky of the net based on the tire lateral force Fy and the predetermined slip angle SA, and
The compliance ep of lateral bending deformation is calculated based on the grounding length L, the self-aligning torque power As0 of the gloss, the torsional rigidity Gmz outside the contact patch of the sidewall, the cornering power Ky of the net, and the cornering power Ky0 of the gloss. Steps and
A step of calculating the lateral bending rigidity Eiz in the belt surface based on the compliance ep of the lateral bending deformation and the lateral elastic modulus Ksy in the sidewall direction, and
including.

By doing so, it is possible to simply calculate the lateral bending rigidity in the belt surface of the tire without requiring complicated fitting. In Japanese Patent Publication No. 2012-171467, fitting based on one or two types of data is required, but in the method of this disclosure, seven types can be simply calculated based on one data of each type. Yes, the procedure is easy.

A block diagram showing a system for calculating the lateral bending rigidity of the tire in the belt surface of the present disclosure. Flowchart showing the in-belt flexural rigidity calculation processing routine executed by the system Diagram of SA-Fy and SA-SAT The figure which shows the measured value and the calculated value of SA, SAT and Fy. Side view showing a tire ground contact state measuring device

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[System for calculating the lateral bending rigidity of the tire in the belt surface]
The system 1 of the present embodiment accepts the measured values of the side rigidity test and the cornering test, and calculates the lateral bending rigidity Eiz in the belt surface of the tire. As shown in FIG. 1, the system 1 includes an acquisition unit 10 that acquires measured values of a side rigidity test and a cornering test from the outside, a net self-aligning torque power calculation unit 11, and a sidewall ground contact surface external torsional rigidity calculation. Section 12, the gloss self-aligning torque power calculation unit 13, the tread rubber shear rigidity calculation unit 14, the gloss cornering power calculation unit 15, the net cornering power calculation unit 16, and the lateral bending deformation compliance calculation unit. It has 17 and an in-plane lateral bending rigidity calculation unit 18. In each of these parts 10 to 18, software and hardware cooperate by executing the in-belt lateral bending rigidity calculation processing routine shown in FIG. 2, which is stored in advance in a computer equipped with a processor, memory, various interfaces, and the like. It works and is realized.

The acquisition unit 10 shown in FIG. 1 acquires the measured values of the tire radius r, the contact length L, the contact width W, the side rigidity test and the cornering test by user operation or via a network. The acquisition unit 10 stores the acquired measurement data in the memory. The tire radius r may be measured by a side rigidity test or a cornering test. The measured value obtained in the side stiffness test is the sidewall axial elastic modulus Ksy. The side rigidity test is known as a test for measuring the rigidity of a sidewall by moving the axis of a tire while the tread of a pneumatic tire assembled with a rim is clamped. In the sidewall stiffness test, in addition to the sidewall axial elastic modulus, the sidewall radial elastic modulus and the sidewall circumferential elastic modulus can be measured, but the sidewall radial elastic modulus and the sidewall circumferential elastic modulus are used in the present disclosure. do not do. Examples of the measured values in the cornering test include the self-aligning torque SAT at a predetermined slip angle SA and the tire lateral force Fy. The cornering test can be carried out by setting the test road surface to a predetermined slip angle SA [degree] by rolling the tire by driving the tire shaft provided with the load cell. The distance from the test road surface to the tire axis is the tire radius r, and the tire lateral force Fy [N] and the self-aligning torque SAT [Nm] can be measured by the load cell. The ground contact length L [mm] and the ground contact width W [mm] can be obtained by the ground contact surface observation test. The ground contact surface observation test is a method of acquiring the ground contact length L and the ground contact width W by making the road surface transparent and optically observing the ground contact surface, and a method of providing a pressure sensor on the road surface and using the pressure value to obtain the ground contact length L and the ground contact width. A method of acquiring W can be mentioned. In the present embodiment, the cornering test and the ground plane observation test are simultaneously performed by the apparatus shown in FIG. 5, but they may be performed by different testing machines. In this specification, the unit is shown in curly braces.

ＳＡ^＋＝ＳＡ^－ ×－１である。Ｆｙ^＋はＳＡ^＋のときのＦｙである。Ｆｙ^－はＳＡ^－のときのＦｙである。ＳＡＴ^＋はＳＡ^＋のときのＳＡＴである。ＳＡＴ^－はＳＡ^－のときのＳＡＴである。Ｆｙは平均値である。ＳＡＴは平均値である。 As shown in FIG. 3, the cornering characteristics (SA-Fy, SA-SAT) of the tire have an offset when SA is 0 degrees, so that Fy ⁺ and SAT ⁺ at SA ^{+ and} SA- Acquires Fy- ^and SAT ^- at the time. The acquisition unit 10 acquires the average value of Fy from Fy ⁺ and Fy ⁻ and the average value of SAT from SAT ⁺ and SAT ⁻ so that Fy and SAT become 0 when SA is 0 degrees. The averaging process executed by the acquisition unit 10 is represented by the following equation (1).

SA ⁺ = SA- × ^-1 . Fy ⁺ is Fy at the time of SA ⁺ . Fy ⁻ is Fy at the time of SA ⁻ . SAT ⁺ is the SAT at the time of SA ⁺ . SAT ^- is the SAT at the time of ^SA- . Fy is an average value. SAT is an average value.

ＳＡ＝１度の場合には、次の式（２－１）のように式を簡略化可能となる。
Ａｓ＝ＳＡＴ／ｔａｎ（π／１８０） …（２－１） The net self-aligning torque power calculation unit 11 shown in FIG. 1 calculates the net self-aligning torque power As [Nm / tan (rad)] based on the self-aligning torque SAT at a predetermined slip angle SA. .. Specifically, it is carried out by the following equation (2).

When SA = 1 degree, the equation can be simplified as in the following equation (2-1).
As = SAT / tan (π / 180)… (2-1)

The sidewall contact patch outer torsional rigidity calculation unit 12 shown in FIG. 1 calculates the sidewall ground contact patch outer torsional rigidity Gmz [Nm / rad] based on the sidewall axial elastic modulus Ksy and the tire radius r. Specifically, it is carried out by the following equation (3).

The gross self-aligning torque power calculation unit 13 shown in FIG. 1 is based on the net self-aligning torque power As and the sidewall grounding surface torsional rigidity Gmz, and the gross self-aligning torque power As0 [Nm / tan (Nm / tan) rad)] is calculated. Specifically, it is carried out by the following equation (4). The net SAT is a net (actually, net) SAT that can be measured by a testing machine. The gloss SAT is a SAT in which the torsional loss of the sidewall is added to the SAT of the net. The average value of SAT when SA = ± 1 degree is equivalent to SAP (self-aligning torque power).

The tread rubber shear rigidity calculation unit 14 shown in FIG. 1 calculates the tread rubber shear rigidity Cy [N / m ³ ] based on the gloss dialogue lining torque power As0, the contact width W, and the contact length L. Specifically, it is carried out by the following equation (5). The front-rear direction in which the tire advances is the x direction, and the ground contact length L is the length of the ground contact surface in the x direction. The lateral direction of the tire is the y direction, and the ground contact width W is the length of the ground contact surface in the y direction.

The gloss cornering power calculation unit 15 shown in FIG. 1 calculates the gloss cornering power Ky0 [N / tan (rad)] based on the tread rubber shear rigidity Cy, the ground contact width W, and the ground contact length L. Specifically, it is carried out by the following equation (6). The average value of the tire lateral force Fy when SA = ± 1 degree is equivalent to the cornering power. Gross cornering power is a force that takes into account the cornering power of the net, the twisting of the sidewalls, and the lateral bending loss of the belt.

ＳＡ＝１度の場合には、次の式（７－１）のように式を簡略化可能となる。
Ｋｙ＝Ｆｙ／ｔａｎ（π／１８０） …（７－１） The net cornering power calculation unit 16 shown in FIG. 1 calculates the net cornering power Ky [N / tan (rad)] based on the tire lateral force Fy and the predetermined slip angle SA. Specifically, it is carried out by the following equation (7).

When SA = 1 degree, the equation can be simplified as in the following equation (7-1).
Ky = Fy / tan (π / 180)… (7-1)

The compliance calculation unit 17 for lateral bending deformation shown in FIG. 1 is based on the ground contact length L, the gross self-aligning torque power As0, the sidewall grounding surface outer torsional rigidity Gmz, the net cornering power Ky, and the gross cornering power Ky0. Compliance ep [1 / (Nm)] for lateral bending deformation is calculated. Specifically, it is carried out by the following equation (8).

The belt in-plane lateral bending rigidity calculation unit 18 shown in FIG. 1 calculates the belt in-plane lateral bending rigidity EIz [Nm ² ] based on the lateral bending deformation compliance ep and the sidewall axial elastic modulus Ksy. Specifically, it is carried out by the following equation (9).

That is, SA, Fy, SAT, Ksy, r, W, and L are obtained as measured values by the side rigidity test, the cornering test, and the ground plane observation. There are eight unknown values, As, Gmz, As0, Cy, Ky0, Ky, ep, and Eiz, and the unknown values can be calculated by the eight equations (2) to (9).

If SA, Fy, SAT, W, and L are measured at once using the tire ground contact state measuring device 5 shown in FIG. 5, errors due to different test conditions can be suppressed as compared with the case of measuring in separate tests. Is possible. The tire ground contact state measuring device 5 is described in Japanese Patent Publication No. 2018-096808. Specifically, the device 5 is mounted on the traveling surface 51, the tire driving device 52 for grounding and rolling the tire T on the traveling surface 51, and a part of the traveling surface 51, and the tire T is in contact with the ground. It has a pressure sensor sheet 53 for measuring the tire, a protective sheet 54 that covers the sheet 53, and a front-rear tension applying mechanism that applies tension to the protective sheet 54 along the tire traveling direction MD. The ground contact length L and the ground contact width W are obtained from the pressure sensor sheet 53, Fy and SAT are obtained from the load cell provided on the tire shaft supporting the tire T, and SA is obtained depending on the test conditions.

Explain that the calculation method of the present disclosure is correct. FIG. 4 is a diagram showing SAT [Nm] and Fy [N] when SA is changed from 0 degree to 1 degree. The solid line plots the measured values. Each value shown in the equations (2) to (9) is calculated from the measured value, and the result of calculating SAT and Fy using each value is shown as a dotted line. The lateral bending rigidity in the belt surface can be calculated, and it can be seen that the SAT and Fy can be reproduced without any problem by the calculation.

[System for calculating the lateral bending rigidity of the tire in the belt surface]
The method of calculating the lateral bending rigidity in the belt surface of the tire performed by the system 1 will be described with reference to FIG. Steps ST1-9 are in no particular order unless the later steps use the output values of the previous step.

First, in step ST1, the acquisition unit 10 shown in FIG. 1 has a tire radius r, a contact length L, a contact width W, a sidewall axial elastic modulus Ksy by a side rigidity test, and a self-alignment at a predetermined slip angle SA by a cornering test. The measured values of the lining torque SAT and the tire lateral force Fy are acquired.

In step ST2, the net self-aligning torque power calculation unit 11 shown in FIG. 1 calculates the net self-aligning torque power As based on the self-aligning torque SAT at a predetermined slip angle SA.

In step ST3, the sidewall ground contact patch outer torsional rigidity calculation unit 12 calculates the sidewall ground contact patch outer torsional rigidity Gmz based on the sidewall axial elastic modulus Ksy and the tire radius r.

In step ST4, the gross self-aligning torque power calculation unit 13 shown in FIG. 1 calculates the gross self-aligning torque power As0 based on the net self-aligning torque power As and the sidewall grounding surface torsional rigidity Gmz. ..

In step ST5, the tread rubber shear rigidity calculation unit 14 shown in FIG. 1 calculates the tread rubber shear rigidity Cy based on the gloss dialogue lining torque power As0, the ground contact width W, and the ground contact length L.

In step ST6, the gloss cornering power calculation unit 15 shown in FIG. 1 calculates the gloss cornering power Ky0 based on the tread rubber shear rigidity Cy, the ground contact width W, and the ground contact length L.

In step ST7, the net cornering power calculation unit 16 shown in FIG. 1 calculates the net cornering power Ky based on the tire lateral force Fy and the predetermined slip angle SA.

In step ST8, the compliance calculation unit 17 for lateral bending deformation shown in FIG. 1 has a grounding length L, a gross self-aligning torque power As0, a sidewall grounding surface outer torsional rigidity Gmz, a net cornering power Ky, and a gross cornering power. The compliance ep of the lateral bending deformation is calculated based on Ky0.

In step ST9, the belt in-plane lateral bending rigidity calculation unit 18 shown in FIG. 1 calculates the belt in-plane lateral bending rigidity Eiz based on the lateral bending deformation compliance ep and the sidewall axial elastic modulus Ksy.

As described above, the method for calculating the lateral bending rigidity in the belt surface of the tire of the present embodiment is
A method executed by one or more processors.
Obtained measured values of tire radius r, ground contact length L, ground contact width W, sidewall axial elastic modulus Ksy by side rigidity test, self-aligning torque SAT at a predetermined slip angle SA by cornering test, and tire lateral force Fy. Step ST1 and
Step ST2 for calculating the self-aligning torque power As of the net based on the self-aligning torque SAT at a predetermined slip angle SA, and
Step ST3 to calculate the sidewall ground contact patch outer torsional rigidity Gmz based on the sidewall axial elastic modulus Ksy and the tire radius r, and
Step ST4 to calculate the gross self-aligning torque power As0 based on the net self-aligning torque power As and the sidewall grounding surface torsional rigidity Gmz,
Step ST5 to calculate the tread rubber shear rigidity Cy based on the gloss line alignment torque power As0, the ground contact width W, and the ground contact length L,
Step ST6 to calculate the gloss cornering power Ky0 based on the tread rubber shear rigidity Cy, the ground contact width W, and the ground contact length L,
Step ST7 to calculate the cornering power Ky of the net based on the tire lateral force Fy and the predetermined slip angle SA,
Step ST8 to calculate the compliance ep of lateral bending deformation based on the grounding length L, the gross self-aligning torque power As0, the sidewall grounding surface torsional rigidity Gmz, the net cornering power Ky, and the gross cornering power Ky0.
It includes step ST9 for calculating the lateral bending rigidity Eiz in the belt surface based on the compliance ep of the lateral bending deformation and the sidewall axial elastic modulus Ksy.

The system for calculating the lateral bending rigidity of the tire in the belt surface of the present embodiment is
Obtained measured values of tire radius r, ground contact length L, ground contact width W, sidewall axial elastic modulus Ksy by side rigidity test, self-aligning torque SAT at a predetermined slip angle SA by cornering test, and tire lateral force Fy. Acquisition unit 10 and
The net self-aligning torque power calculation unit 11 that calculates the net self-aligning torque power As based on the self-aligning torque SAT at a predetermined slip angle SA,
The sidewall ground plane outer torsional rigidity calculation unit 12 that calculates the sidewall ground plane outer torsional rigidity Gmz based on the sidewall axial elastic modulus Ksy and the tire radius r, and
The Gloss self-aligning torque power calculation unit 13 that calculates the gross self-aligning torque power As0 based on the net self-aligning torque power As and the sidewall grounding surface torsional rigidity Gmz,
The tread rubber shear rigidity calculation unit 14 that calculates the tread rubber shear rigidity Cy based on the gloss line alignment torque power As0, the ground contact width W, and the ground contact length L, and
The gloss cornering power calculation unit 15 that calculates the gloss cornering power Ky0 based on the tread rubber shear rigidity Cy, the ground contact width W, and the ground contact length L,
The net cornering power calculation unit 16 that calculates the net cornering power Ky based on the tire lateral force Fy and the predetermined slip angle SA,
Compliance for lateral bending deformation ep is calculated based on the grounding length L, the self-aligning torque power As0 of the gloss, the torsional rigidity Gmz outside the sidewall grounding surface, the cornering power Ky of the net, and the cornering power Ky0 of the gross. Calculation unit 17 and
The belt in-plane flexural rigidity calculation unit 18 that calculates the belt in-plane lateral bending rigidity EZ based on the lateral bending deformation compliance ep and the sidewall axial elastic modulus Ksy,
To prepare for.

By doing so, it is possible to simply calculate the lateral bending rigidity in the belt surface of the tire without requiring complicated fitting. In Japanese Patent Publication No. 2012-171467, fitting based on one or two types of data is required, but in the method of this disclosure, seven types can be simply calculated based on one data of each type. Yes, the procedure is easy.

In the present embodiment, the predetermined slip angle SA is preferably 1 degree.
As described above, if the SA is once, the equation can be simplified as in the equation (2-1), and the measurement cost can be reduced by reducing the number of cornering test conditions.

In the present embodiment, the measured values of the ground contact length L, the ground contact width W, the self-aligning torque SAT and the tire lateral force Fy at a predetermined slip angle SA are preferably measured by one test device.

In this way, if SA, Fy, SAT, W, and L are measured at once, it is possible to suppress an error due to different test conditions as compared with the case of measuring in separate tests. Of course, there is a possibility that an error may be included by making the test different, but the self-aligning torque SAT and the tire lateral force Fy at a predetermined slip angle SA are measured in the cornering test, and another test, the ground contact surface observation test. It is also possible to measure the ground contact length L and the ground contact width W at.

The program according to this embodiment is a program that causes one or more processors to execute the above method. By executing this program, it is possible to obtain the effects of the above method. In other words, it can be said that the above method is used.

Although the embodiments of the present disclosure have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present disclosure is set forth not only by the description of the embodiment described above but also by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

For example, the execution order of each process such as operation, procedure, step, and step in the device, system, program, and method shown in the claims, specification, and drawings may be the output of the previous process. Unless used in processing, it can be realized in any order. Even if the scope of claims, the specification, and the flow in the drawings are explained using "first", "next", etc. for convenience, it does not mean that it is essential to execute in this order. ..

For example, although each part 10 to 18 shown in FIG. 1 is realized by executing a predetermined program on the CPU of a computer, each part may be configured by a dedicated circuit. In the present embodiment, the processors in one computer implement each part 10 to 18, but they may be distributed and implemented in at least one or a plurality of processors.

It is possible to adopt the structure adopted in each of the above embodiments in any other embodiment. The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present disclosure.

1 System 10 Acquisition unit 11 Net self-aligning torque power calculation unit 12 Sidewall ground plane torsional rigidity calculation unit 13 Gross self-aligning torque power calculation unit 14 Tread rubber shear rigidity calculation unit 15 Gross cornering power calculation unit 16 Net cornering power calculation unit 17 Lateral bending deformation compliance calculation unit 18 Belt in-plane lateral bending rigidity calculation unit r Tire radius Ksy Sidewall Axial elastic coefficient,
L Grounding length W Grounding width SA Predetermined slip angle SAT Self-aligning torque Fy Tire lateral force As Net self-aligning torque power Gmz Sidewall ground surface Torsion rigidity As0 Gross self-aligning torque power Cy Tread rubber Shear rigidity Ky0 Gross cornering power Ky Net cornering power ep Lateral bending deformation compliance EIz Belt in-plane lateral bending rigidity

Claims (7)

A method executed by one or more processors.
Obtained measured values of tire radius r, ground contact length L, ground contact width W, sidewall axial elastic modulus Ksy by side rigidity test, self-aligning torque SAT at a predetermined slip angle SA by cornering test, and tire lateral force Fy. Steps to take and
A step of calculating the self-aligning torque power As of the net based on the self-aligning torque SAT at the predetermined slip angle SA, and
A step of calculating the sidewall ground contact patch outer torsional rigidity Gmz based on the sidewall axial elastic modulus Ksy and the tire radius r, and
A step of calculating the gross self-aligning torque power As0 based on the net self-aligning torque power As and the sidewall grounding surface torsional rigidity Gmz.
A step of calculating the tread rubber shear rigidity Cy based on the gloss line lining torque power As0, the ground contact width W, and the ground contact length L.
A step of calculating the gloss cornering power Ky0 based on the tread rubber shear rigidity Cy, the ground contact width W, and the ground contact length L.
A step of calculating the cornering power Ky of the net based on the tire lateral force Fy and the predetermined slip angle SA, and
The compliance ep of lateral bending deformation is calculated based on the grounding length L, the self-aligning torque power As0 of the gloss, the torsional rigidity Gmz outside the contact patch of the sidewall, the cornering power Ky of the net, and the cornering power Ky0 of the gloss. Steps and
A step of calculating the lateral bending rigidity Eiz in the belt surface based on the compliance ep of the lateral bending deformation and the lateral elastic modulus Ksy in the sidewall direction, and
A method of calculating the lateral bending rigidity in the belt surface of a tire, including. The method according to claim 1, wherein the predetermined slip angle SA is 1 degree. The one according to claim 1 or 2, wherein the measured values of the ground contact length L, the ground contact width W, the self-aligning torque SAT at the predetermined slip angle SA, and the tire lateral force Fy are measured by one test device. Method. Obtained measured values of tire radius r, ground contact length L, ground contact width W, sidewall axial elastic modulus Ksy by side rigidity test, self-aligning torque SAT at a predetermined slip angle SA by cornering test, and tire lateral force Fy. Acquisition department and
A net self-aligning torque power calculation unit that calculates the net self-aligning torque power As based on the self-aligning torque SAT at the predetermined slip angle SA.
A sidewall ground contact patch outer torsional rigidity calculation unit that calculates the sidewall ground contact patch outer torsional rigidity Gmz based on the sidewall axial elastic modulus Ksy and the tire radius r.
A gloss self-aligning torque power calculation unit that calculates the gross self-aligning torque power As0 based on the net self-aligning torque power As and the sidewall grounding surface torsional rigidity Gmz.
A tread rubber shear rigidity calculation unit that calculates the tread rubber shear rigidity Cy based on the gloss line lining torque power As0, the ground contact width W, and the ground contact length L.
A gloss cornering power calculation unit that calculates a gloss cornering power Ky0 based on the tread rubber shear rigidity Cy, the ground contact width W, and the ground contact length L.
A net cornering power calculation unit that calculates a net cornering power Ky based on the tire lateral force Fy and the predetermined slip angle SA.
The compliance ep of lateral bending deformation is calculated based on the grounding length L, the self-aligning torque power As0 of the gloss, the torsional rigidity Gmz outside the contact patch of the sidewall, the cornering power Ky of the net, and the cornering power Ky0 of the gloss. Compliance calculation unit for lateral bending deformation and
A belt in-plane lateral bending rigidity calculation unit that calculates the belt in-plane lateral bending rigidity EZ based on the lateral bending deformation compliance ep and the sidewall axial elastic modulus Ksy.
A system that calculates the lateral bending rigidity of a tire in the belt surface. The system according to claim 4, wherein the predetermined slip angle SA is 1 degree. The fourth or fifth aspect of the present invention, wherein the measured values of the ground contact length L, the ground contact width W, the self-aligning torque SAT at the predetermined slip angle SA, and the tire lateral force Fy are measured by one test device. system. A program that causes one or more processors to execute the method according to any one of claims 1 to 3.

Images