JP2013180740A - Tire performance simulation method, tire performance simulation device, and tire performance simulation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate the pattern noise performance of a modified tread pattern in which the positions of tread block trains in a tire peripheral direction are shifted, with less manhours and relatively good accuracy.SOLUTION: A tire performance simulation method includes calculating an in-contact-area fluctuating force waveform as a time history of in-contact-area fluctuating force generated in a contact area where a tire has ground contact with a road surface V, with respect to each of a plurality of tread block trains arranged in a tire peripheral direction, setting a plurality of shift patterns in which the shift amounts of the plurality of tread block trains from prefixed reference positions in the peripheral direction are set, respectively, adding the in-contact-area fluctuating force waveforms shifted depending on the shift amounts of the plurality of tread block trains from the prefixed reference positions in the peripheral direction, for the plurality of shift patterns, respectively, and finding differences between a maximum value and a minimum value for the in-contact-area fluctuating force from the added in-contact-area fluctuating force waveforms for the plurality of shift patterns, respectively, to select the shift pattern in which the found difference is a prefixed threshold value or smaller.

Description

  The present invention relates to a tire performance simulation method, a tire performance simulation device, and a tire performance simulation program, and more particularly, a tire performance simulation method, a tire performance simulation device, and a tire for analyzing tire performance by a finite element method. It relates to a performance simulation program.

  One of the phenomena that is a problem among the noises caused by tire tread patterns is pattern noise (vehicle interior noise during traveling). For example, as described in Patent Document 1, the pattern noise is caused by fluctuations in the tire axle force that occurs in a rigid discontinuous portion such as a lug groove.

  In order to predict and evaluate the pattern noise performance, for example, as described in Patent Document 2, variation in axle force obtained by FEM rolling calculation using a tire model with a pattern, contact for each rib (each tread block row), and so on. Predicted from the rolling time-series waveform of the fluctuating force in the ground (the sum of the fluctuating forces in the ground plane of all tread block rows corresponds to the axle force fluctuation).

  In order to improve pattern noise, the geometrical relationship between the ground shape and groove is changed by shifting the circumferential position of each tread block row, and the time series waveform of the in-plane variation force for each tread block row is changed. A method of shifting the phase and canceling each of them is used.

JP 2003-219916 A Japanese Patent No. 4087193

  However, in order to confirm the pattern noise performance of the corrected pattern in which the tire circumferential direction position of the tread block row is shifted, it is necessary to perform FEM rolling calculation from pattern modeling again, or to actually measure using an actual tire, There was a problem that man-hours and costs increased.

  The present invention has been made in view of the above facts, and the pattern noise performance of the modified tread pattern in which the tire circumferential direction position of the tread block row is shifted can be evaluated with a small number of man-hours and relatively good accuracy. An object of the present invention is to provide a tire performance simulation method, a tire performance simulation device, and a tire performance simulation program.

  In order to achieve the above object, the tire performance simulation method according to the first aspect of the present invention is generated in a contact surface where the tire contacts the road surface for each of a plurality of tread block rows arranged in the circumferential direction of the tire. A calculation step for calculating a fluctuation force waveform in the contact surface that is a time history of the change force in the contact surface, and a plurality of shift patterns in which a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows is set. For each of the plurality of shifting patterns, the in-plane fluctuating force waveform is shifted in accordance with a shift amount of the plurality of tread block rows with respect to a predetermined reference position in the circumferential direction. And adding each of the plurality of shifting patterns from the added ground surface fluctuation force waveform in the ground plane. Obtains the difference between the maximum value and the minimum value of the power, selecting a shifting pattern obtained difference is equal to or less than a predetermined threshold, characterized in that it comprises a.

  According to the present invention, without creating a tire model in which the position of the tread block row in the tire circumferential direction is shifted, the contact force of the entire tread block row is obtained by shifting and adding the in-plane variation force waveform of each tread block row. Since the in-ground fluctuating force waveform can be obtained, the pattern noise performance of the corrected tread pattern can be evaluated with relatively little accuracy and relatively good accuracy.

  In addition, as described in claim 2, the shift amount is preferably set in a range of 5 to 15% with respect to a maximum pitch among the pitches of the plurality of tread block rows.

  According to a third aspect of the present invention, there is provided the tire performance simulation apparatus according to the first aspect of the present invention, wherein for each of the plurality of tread block rows arranged in the circumferential direction of the tire, the time history of the in-ground fluctuating force generated in the contact surface where the tire contacts the road surface. Calculating means for calculating the in-plane fluctuating force waveform, and setting means for setting a plurality of shift patterns each setting a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows, For each of the plurality of shifting patterns, according to the amount of shifting with respect to the predetermined reference position in the circumferential direction of the plurality of tread block rows, adding means for shifting and adding the in-plane fluctuating force waveform, and For each of the plurality of shifting patterns, a difference between the maximum value and the minimum value of the in-surface fluctuating force is obtained from the added in-surface fluctuating force waveform, and the difference is obtained. Selection means for differences to select the shifting pattern becomes less than a predetermined threshold value which, characterized in that it comprises a.

  According to a fourth aspect of the present invention, there is provided a tire performance simulation program that records, for each of a plurality of tread block rows arranged in a circumferential direction of a tire, a time history of a fluctuating force in a contact surface that is generated in a contact surface on which the tire contacts the road surface. A calculation step for calculating the in-plane fluctuating force waveform, and a setting step for setting a plurality of shift patterns each setting a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows, For each of the plurality of shifting patterns, an adding step of shifting and adding the ground surface fluctuation force waveform according to the amount of shifting with respect to the predetermined reference position in the circumferential direction of the plurality of tread block rows, and For each of the plurality of shifting patterns, the maximum value and the minimum value of the in-surface fluctuating force are calculated from the added in-surface fluctuating force waveform. Obtains the difference between, characterized in that to execute the steps of selecting a shifting pattern obtained difference is equal to or less than a predetermined threshold, the process including the computer.

  According to the present invention, there is an effect that the pattern noise performance of the modified tread pattern in which the position in the tire circumferential direction of the tread block row is shifted can be evaluated with a small number of man-hours and relatively good accuracy.

It is the schematic of the computer for implementing performance prediction of a tire. It is a schematic block diagram of a computer. It is a flowchart of a tire performance simulation program. It is a partial top view of a tire model. It is a figure which shows an example of the fluctuating force waveform in the contact surface of each tread block row | line | column. It is a figure which shows the in-plane fluctuating force waveform which added the in-surface fluctuating force waveform of each tread block row | line | column. It is a figure which shows an example of the fluctuation force waveform in a contact surface when the circumferential direction position of the tire of each tread block row | line | column is shifted. It is a figure which shows the in-ground fluctuating force waveform which added the in-surface fluctuating force waveform when the circumferential direction position of the tire of each tread block row | line | column is shifted.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows, as an example, an outline of a computer as a tire performance simulation apparatus for creating and designing a tire model of a pneumatic tire, performing performance analysis, and the like. This computer includes a keyboard 10 for inputting data and the like, a computer 12 for creating and designing a three-dimensional tire model in accordance with a pre-stored processing program, and a display for displaying calculation results and various screens by the computer 12. 14 and a mouse 16 for performing an operation of moving the cursor displayed on the display 14 to a desired position, selecting, deselecting, or dragging a menu item or object at the cursor position. Has been.

  As shown in FIG. 2, the computer 12 includes a CPU (Central Processing Unit) 12A, a ROM (Read Only Memory) 12B, a RAM (Random Access Memory) 12C, a non-volatile memory 12D, and an input / output interface (I / O) 12E. Are connected to each other via a bus 12F.

  Connected to the I / O 12E are a keyboard 10, a display 14, a mouse 16, a hard disk 18, and a CD-ROM drive 22 into which a CD-ROM 20 as a recording medium can be inserted and removed.

  The hard disk 18 stores a tire performance simulation program, which will be described later, and various parameters and data necessary for the execution thereof. The CPU 12A reads and executes a tire performance simulation program stored in the hard disk 18.

  Note that a tire performance simulation program, which will be described later, can be read from and written to the CD-ROM 20 using, for example, the CD-ROM drive 22, so that a tire performance simulation program, which will be described later, is recorded in the CD-ROM 20 in advance. The tire performance simulation program recorded on the CD-ROM 20 may be read and executed via the CD-ROM drive 22. Further, the recording medium is not limited to the CD-ROM, but includes an optical disk such as a DVD-ROM and a magneto-optical disk such as an MD or MO. A DVD-ROM drive, MD drive, MO drive or the like may be used.

  Next, as a function of the present embodiment, a processing routine of a tire performance simulation program executed by the computer 12 will be described with reference to a flowchart shown in FIG.

  First, in step 100, a tire tire model for creating a tire design proposal into a numerical analysis model is created. The creation of the tire model differs slightly depending on the numerical analysis method used. As a numerical analysis method, for example, a finite element method (FEM) can be used.

  Accordingly, the tire model created in step 100 is divided into a plurality of elements by element division corresponding to the finite element method (FEM), that is, mesh division, and the tire is created based on a numerical / analytical method. This is the numerical value of the input data format for the program. This element division means dividing an object such as a tire and a road surface (described later) into several small (finite) small parts, that is, elements. After calculating each element and calculating all the elements, the whole response can be obtained by adding all the elements.

  In creating a tire model, first, a tire radial section model (tire section model) is created. The outer shape of the tire cross-section model can be created, for example, using values obtained by measuring the tire outer shape with a laser shape measuring instrument or the like. In addition, an accurate value such as a design drawing and actual tire cross-section data can be used for the structure inside the tire.

  After the tire cross-section model is created, the tire cross-section model is developed in one round (360 degrees) in the circumferential direction to create a three-dimensional (3D) model of the tire. In this way, a tire model is created.

  FIG. 4 shows a plan view of a part of the created tire model. As shown in the figure, the tire model 30 includes tread block rows Rib1 to Rib4 in which a plurality of tread blocks are arranged along the circumferential direction S of the tire.

  After the tire model is created as described above, a road surface model is created in step 102. This road surface model is created by dividing the road surface on which the tire contacts the ground into a plurality of elements.

  After creating the tire model and the road surface model as described above, the routine proceeds to step 104, where boundary conditions are set. The boundary conditions are necessary for analysis of the tire model, that is, for simulating the behavior of the tire, and are various conditions given to the tire model.

  For example, in the case of tire rolling for rolling the tire model, the boundary condition setting in step 104 is determined in advance as at least one of internal pressure, rotational displacement, and straight displacement (displacement may be force or speed). Load.

  In the next step 106, rolling calculation of the tire model is performed. That is, deformation calculation of the tire model is performed. This tire model deformation calculation is based on the finite element method, and the tire model is subjected to deformation calculation given boundary conditions. In the present embodiment, for each of the tread block rows Rib1 to Rib4 shown in FIG. 4, the in-surface fluctuating force waveform that is the time history of the in-surface fluctuating force generated in the contact surface where the tire contacts the road surface is obtained. . FIG. 5 shows an example of the in-ground fluctuating force waveform of each of the tread block rows Rib1 to Rib4.

  In step 108, the in-ground fluctuating force waveforms of the tread block rows Rib1 to Rib4 are added. That is, the in-surface fluctuating force waveform in the entire tread block row Rib1 to Rib4 is obtained by adding the in-ground fluctuating force in each time of the tread block row Rib1 to Rib4. FIG. 6 shows the in-ground fluctuating force waveform obtained by adding all the in-ground fluctuating force waveforms of the tread block rows Rib1 to Rib4 shown in FIG. The ground surface variation force waveform obtained by adding all the ground surface variation force waveforms of the tread block rows Rib1 to Rib4 corresponds to the axle force variation waveform.

  In step 110, among the tread block rows Rib1 to Rib4, a tread block row that is shifted upward or downward with respect to a predetermined reference position in the circumferential direction S of the tire shown in FIG. 4, a shift pattern that includes a shift direction, and a shift amount. Set more than one. The setting of the shift pattern may be set by the user or may be determined in advance.

  An example of the shifting pattern is shown below.

なお、トレッドブロック列Ｒｉｂ１〜Ｒｉｂ４の各々をタイヤの周方向Ｓの予め定めた基準位置に配置したパターンを基本パターンとしている。すなわち、ステップ１００で作成したタイヤモデルにおけるトレッドブロック列Ｒｉｂ１〜Ｒｉｂ４の配置を基本パターンとして、ずらしパターン１は、基本パターンに対して、トレッドブロック列Ｒｉｂ１をタイヤの周方向Ｓに沿って図４において下方に２ｍｍずらすと共に、トレッドブロック列Ｒｉｂ４をタイヤの周方向Ｓに沿って図４において上方に２ｍｍずらしたパターンである。また、ずらしパターン２は、基本パターンに対して、トレッドブロック列Ｒｉｂ２をタイヤの周方向Ｓに沿って図４において下方に２ｍｍずらすと共に、トレッドブロック列Ｒｉｂ３をタイヤの周方向Ｓに沿って図４において上方に２ｍｍずらしたパターンである。また、ずらしパターン３は、基本パターンに対して、トレッドブロック列Ｒｉｂ１、Ｒｉｂ２をタイヤの周方向Ｓに沿って図４において下方に２ｍｍずらすと共に、トレッドブロック列Ｒｉｂ３、Ｒｉｂ４をタイヤの周方向Ｓに沿って図４において上方に２ｍｍずらしたパターンである。

A basic pattern is a pattern in which each of the tread block rows Rib1 to Rib4 is arranged at a predetermined reference position in the circumferential direction S of the tire. That is, using the arrangement of the tread block rows Rib1 to Rib4 in the tire model created in step 100 as a basic pattern, the shift pattern 1 is shown in FIG. 4 along the circumferential direction S of the tire with respect to the basic pattern. This is a pattern in which the tread block row Rib4 is shifted 2 mm upward in FIG. 4 along the circumferential direction S of the tire while being shifted 2 mm downward. Further, in the shifting pattern 2, the tread block row Rib2 is shifted 2 mm downward in FIG. 4 along the circumferential direction S of the tire with respect to the basic pattern, and the tread block row Rib3 is shifted along the circumferential direction S of the tire in FIG. The pattern is shifted upward by 2 mm. Further, the shifting pattern 3 shifts the tread block rows Rib1 and Rib2 downward by 2 mm in FIG. 4 along the circumferential direction S of the tire with respect to the basic pattern, and the tread block rows Rib3 and Rib4 in the circumferential direction S of the tire. 4 is a pattern shifted by 2 mm upward in FIG.

  In addition, if the range of shift amount is enlarged, calculation time will increase in connection with it and prediction accuracy will deteriorate. For this reason, the shift amount is set to an amount (length) within a range of 5 to 15% with respect to the maximum pitch among the pitches of the tread block rows Rib1 to Rib4 (distance between the tread blocks in the tire circumferential direction). It is preferable to do.

  In step 112, for each of the set shifting patterns, the in-plane fluctuating force waveform of each of the tread block rows Rib1 to Rib4 of the basic pattern is shifted according to the shifting amount of each tread block row, and these are added (summed). .

  For example, in the shift pattern 1, since the tread block row Rib1 is shifted downward by 2 mm with respect to the basic pattern, the in-plane fluctuating force waveform shown in FIG. Shift to. Further, in the shifting pattern 1, since the tread block row Rib4 is shifted upward by 2 mm, the in-plane fluctuating force waveform shown in FIG. 5 is shifted to the right by the time corresponding to the amount shifted by 2 mm upward. Thereafter, the in-ground fluctuating force waveforms of the tread block rows Rib1 to Rib4 are added. Similarly, with respect to the shifting patterns 2 and 3, the in-plane fluctuating force waveform is shifted according to the shift amount, and the in-ground fluctuating force waveforms of the tread block rows Rib1 to Rib4 are added.

  FIG. 7 shows the in-ground fluctuating force waveform when the tread block rows Rib1 to Rib4 are shifted by the shift pattern 3. Further, FIG. 8 shows a ground surface variation force waveform obtained by adding the ground surface variation force waveforms of the tread block rows Rib1 to Rib4 shown in FIG.

  In step 114, a pattern in which the difference between the maximum value and the minimum value of the in-plane variation force is equal to or less than a predetermined threshold is selected from the basic pattern and the shift pattern in-ground variation force waveform calculated in step 112. . If there are a plurality of patterns in which the difference between the maximum value and the minimum value of the in-plane fluctuating force is less than or equal to a predetermined threshold (for example, 5 N or less), the difference between the maximum value and the minimum value of the in-surface fluctuating force is Select the smallest pattern.

  For example, as shown in FIG. 6, when the in-ground fluctuating force waveform of the entire tread block row Rib1 to Rib4 in the basic pattern is seen, the difference between the maximum value and the minimum value of the in-ground fluctuating force is about 10N. As shown in FIG. 8, when the in-ground fluctuating force waveform of the entire tread block row Rib1 to Rib4 in the shifting pattern 3 is seen, the difference between the maximum value and the minimum value of the in-ground fluctuating force is reduced to 5N or less. I understand that. Therefore, in this case, the pattern noise can be reduced with the shifted pattern 3 than with the basic pattern.

  As described above, in this embodiment, instead of creating a tire model in which each tread block row is shifted and calculating the in-plane variation force waveform of the entire tread block row, the in-ground variation force of each tread block row is calculated. By shifting and adding the waveforms to calculate the in-plane fluctuating force waveform of the entire tread block row, the pattern noise performance of the modified tread pattern in which the tire circumferential position of the tread block row is shifted can be reduced with less man-hours and relatively It can be evaluated with good accuracy.

  Also, by changing the time-series shift amount of the in-plane fluctuating force waveform for each tread block row to various values and summing the in-surface fluctuating force for each tread block row, the axle force fluctuation can be easily calculated. By calculating and searching for a shift amount that minimizes this, optimization from the pattern noise performance aspect of the circumferential position of each tread block row can be easily performed.

  (Example)

  Next, examples of the present invention will be described. For the shifting patterns 1 to 3 shown in Table 1, when the simple calculation shown in FIG. 3 described in the present embodiment is executed, and the tire model in which the tread block row is shifted are respectively created and the FEM rolling calculation is executed. The time taken in each of the case and the case where a tire with a shifted tread block row is created and measured is shown below.

表２に示すように、本実施形態で説明した簡易計算を実行することにより、工数を大幅に短縮できることが判った。

As shown in Table 2, it was found that the number of man-hours can be significantly reduced by executing the simple calculation described in the present embodiment.

  In addition, the tire performance of the shift patterns 1 to 3 in the case where the tire performance of the basic pattern is normalized as 100 for each of the above simple calculation, FEM rolling calculation, and actual measurement is shown below.

表３に示すように、簡易計算の結果が、ＦＥＭ転動計算及び実測と定性的にほぼ一致することが判り、簡易計算においても十分にタイヤ性能を評価できることが判った。

As shown in Table 3, it was found that the result of the simple calculation almost qualitatively coincided with the FEM rolling calculation and the actual measurement, and it was found that the tire performance can be sufficiently evaluated even in the simple calculation.

10 Keyboard 12 Computer 14 Display 16 Mouse 18 Hard Disk 20 CD-ROM
22 CD-ROM drive

Claims (4)

A calculation step of calculating a ground-in-plane fluctuating force waveform that is a time history of a ground-in-plane fluctuating force generated in the ground contact surface where the tire contacts the road surface for each of a plurality of tread block rows arranged in the tire circumferential direction. When,
A setting step for setting a plurality of shift patterns each setting a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows;
For each of the plurality of shifting patterns, an adding step for shifting and adding the in-plane fluctuating force waveform according to a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows,
For each of the plurality of shifting patterns, a difference between the maximum value and the minimum value of the in-surface fluctuating force is obtained from the added in-surface fluctuating force waveform, and the obtained difference is equal to or less than a predetermined threshold value. A step of selecting
A tire performance simulation method including: The tire performance simulation method according to claim 1, wherein the shift amount is set within a range of 5 to 15% with respect to a maximum pitch among pitches of the plurality of tread block rows. Calculation means for calculating, for each of a plurality of tread block rows arranged in the circumferential direction of the tire, an in-ground fluctuating force waveform that is a time history of in-ground fluctuating force generated in a contact surface where the tire contacts the road surface When,
Setting means for setting a plurality of shift patterns, each of which sets a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows;
For each of the plurality of shifting patterns, an adding means that shifts and adds the in-plane fluctuating force waveform according to a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows, and
For each of the plurality of shifting patterns, a difference between the maximum value and the minimum value of the in-surface fluctuating force is obtained from the added in-surface fluctuating force waveform, and the obtained difference is equal to or less than a predetermined threshold value. A selection means for selecting
Tire performance simulation equipment including A calculation step of calculating a ground-in-plane fluctuating force waveform that is a time history of a ground-in-plane fluctuating force generated in the ground contact surface where the tire contacts the road surface for each of a plurality of tread block rows arranged in the tire circumferential direction. When,
A setting step for setting a plurality of shift patterns each setting a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows;
For each of the plurality of shifting patterns, an adding step for shifting and adding the in-plane fluctuating force waveform according to a shift amount with respect to a predetermined reference position in the circumferential direction of the plurality of tread block rows,
For each of the plurality of shifting patterns, a difference between the maximum value and the minimum value of the in-surface fluctuating force is obtained from the added in-surface fluctuating force waveform, and the obtained difference is equal to or less than a predetermined threshold value. A step of selecting
Tire performance simulation program for causing a computer to execute processing including

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