JP2006293631A - Method of and device for predicting tire performance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of and device for predicting tire performance for shortening a time to be spent on numerical calculation while maintaining precision for predicting the performance of a tire. <P>SOLUTION: The method includes: a step A for preparing a tire model by modeling a tire by the finite number of elements; and a step B for predicting the performance of the tire model prepared by the step A by using a finite element method, wherein a cross-sectional model as the width direction cross-section of the tire model corresponding to the width direction cross-section of the tire prepared by the step A has a shape which corresponds from the position outside the tire diameter direction of one bead core of the tire via a side wall and a tread section to the position outside the tire diameter direction of the other bead core. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tire performance prediction method and a tire performance prediction apparatus that predict tire performance.

  Conventionally, by using a finite element method (Finite Element Method (FEM)) or the like to simulate a tire model in which a pneumatic tire (hereinafter referred to as a tire) is modeled with a finite number of elements, the tire performance (for example, running) It is known to predict (performance).

  Specifically, the tire model performance, that is, the tire performance is correctly predicted by synthesizing the tread pattern model modeled with a finite number of elements at the position corresponding to the tire tread pattern into the tire model described above. Techniques are disclosed (for example, see Patent Documents 1 and 2).

This eliminates the need to design / manufacture prototype tires, test them with the prototype tires mounted on a vehicle or drum tester, and save a lot of time, money, and labor for designing / manufacturing and testing prototype tires. In addition, facilities and the like can be reduced.
Japanese Patent No. 3314082 Japanese Patent No. 3363442

  However, the current situation is that it is desired to further reduce the time required for analyzing the performance of the tire model (that is, the time required for numerical analysis) as compared with the conventional technique. For this reason, it is conceivable to reduce the time required for numerical analysis by making the size of the above-described element larger (coarse) than the size of a normal element, but the performance of the tire cannot be predicted correctly.

  Therefore, the present invention has been made in view of the above-described problems, and a tire performance prediction method and a tire performance prediction apparatus capable of reducing the time required for numerical calculation while maintaining the accuracy of predicting tire performance. The purpose is to provide.

  As a result of intensive studies to solve the above situation, the inventors have omitted the shape corresponding to the inner side in the tire radial direction from the position outside the tire radial direction of the bead core in the tire from the tire model, and thereby the time required for the numerical analysis It was found that can be greatly shortened.

  The bead core in this tire model meshes with the rim wheel during deformation due to the load of the tire or rolls during simulation and acts as a rigid body. Therefore, even if the shape corresponding to the inside in the tire radial direction from the position outside the tire radial direction of the bead core in the tire is omitted from the tire model, it has been found that the performance of the tire model, that is, the performance of the tire can be correctly predicted. .

  First, the feature of the present invention is that a step A for creating a tire model (tire model 100) in which a tire is modeled by a finite number of elements (elements 10a, 10b, 10c...) And a finite element method are used. The tire performance prediction method includes step B for predicting the performance of the tire model created in step A, and a cross-section model (cross-section model) that is a cross-section in the width direction of the tire model corresponding to the cross-section in the width direction of the tire created in step A 10) is the outer side in the tire radial direction of the other bead core from the position (position P) on the outer side in the tire radial direction of one bead core in the tire via the sidewall (side wall SW) and the tread part (tread part TR). The gist is that the shape corresponds to the position (position P).

  According to such an invention, a cross-sectional model that is a cross-section in the width direction of the tire model corresponding to a cross-section in the width direction of the tire is from the position on the tire radial direction outer side of one bead core in the tire via the sidewall and the tread portion, The shape corresponding to the outer position in the tire radial direction of the other bead core, that is, the shape corresponding to the inner side in the tire radial direction from the position in the tire radial direction of the bead core in the tire is omitted from the tire model. The time required can be greatly reduced. That is, the efficiency of tire development can be improved.

  Also, since the bead core in the tire model corresponding to the bead core in the tire meshes with the rim wheel and works as a rigid body at the time of deformation due to the load of the tire during rolling, it works from the position radially outside the bead core in the tire. Even if the shape corresponding to the inner side in the tire radial direction is omitted from the tire model, the performance of the tire model, that is, the performance of the tire can be correctly predicted.

  In the present invention, step A includes step A-1 for creating a cross-sectional model, and step A- for creating the tire model by developing the cross-sectional model in the tire model circumferential direction corresponding to the tire circumferential direction in the tire. 2 is preferable.

  As a result, tire modeling, that is, creation of a tire model can be easily performed, so that the time required for creating the tire model can be shortened. That is, the efficiency of tire development can be improved.

  In the present invention, a tread pattern model (tread pattern model 300) modeled by a finite number of elements (elements 300a, 300b, 300c,...) Is arranged at a position corresponding to the tread pattern of the tire. It is preferable that

  As a result, even in the tire model in which the tread pattern model is arranged, the time required for the numerical analysis is shortened as compared with the tire model in which the tire radial outer side is modeled from the position in the tire radial inner side of the bead core in the tire. be able to. Moreover, it is possible to predict the performance close to that of an actual tire, that is, the performance of the tire correctly, in particular, the running performance, drainage performance, snow performance, noise performance, etc. among the tire performance.

  Further, in the present invention, the position of the bead core in the tire radial direction of the tire model corresponding to the position of the bead core in the tire radial direction in the tire has a displacement or speed applied to the bead core, acceleration, rotational displacement, angular velocity, angular acceleration, Information including at least one of the forces is preferably held.

  This makes it possible to correctly predict tire performance. Specifically, the bead core in the tire works from the position outside the tire radial direction to the inner side in the tire radial direction because it engages with the rim wheel during the simulation due to the load of the tire during rolling and acts as a rigid body. Since the information on the bead core is held at the position on the outer side in the tire radial direction of the bead core in the tire model corresponding to the position on the outer side in the tire radial direction, the performance of the tire can be predicted more correctly.

  In the present invention, a tire model creating means (tire model creating unit 212b) for creating a tire model obtained by modeling a tire with a finite number of elements, and a tire model created by the tire model creating means using a finite element method. The tire performance prediction device is provided with a performance prediction means (performance prediction unit 212d) for predicting the performance of the tire, and a cross-sectional model that is a cross section in the width direction of the tire model corresponding to the cross section in the width direction of the tire created by the tire model creation means is The gist of the present invention is that the shape corresponds to the position on the outer side in the tire radial direction of the other bead core through the sidewall and the tread portion from the position on the outer side in the tire radial direction of one bead core in the tire.

  According to such a feature, a cross-sectional model that is a cross-section in the width direction of the tire model corresponding to the cross-section in the width direction of the tire, from the position on the tire radial direction outer side of one bead core in the tire, via the sidewall and the tread portion, The shape of the other bead core corresponding to the outer position in the tire radial direction, that is, the shape corresponding to the inner side in the tire radial direction from the position of the tire bead core in the tire radial direction is omitted from the tire model. It is possible to reduce the time required for numerical calculation while maintaining the accuracy of predicting.

  ADVANTAGE OF THE INVENTION According to this invention, the tire performance prediction method and tire performance prediction apparatus which can shorten the time concerning numerical calculation can be provided, maintaining the precision which estimates the performance of a tire.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Configuration of tire performance prediction device)
A tire performance prediction apparatus 200 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a tire performance prediction apparatus 200 in the present embodiment.

  As shown in FIG. 1, the tire performance prediction apparatus 200 includes an input unit 211, a processing unit 212 (CPU), a storage unit 213, a display unit 214, and a program holding unit.

  The input unit 211 is a device such as a keyboard and a mouse, and inputs information (such as various information and boundary conditions described later) necessary for simulating the tire model 100 (not shown in FIG. 1, see FIG. 4). The Information necessary for the simulation input to the input unit 211 is transmitted to the processing unit 212.

  The processing unit 212 includes various information setting units 212a, a tire model creation unit 212b (tire model creation means), a boundary condition setting unit 212c, a performance prediction unit 212d (performance prediction unit), and a result output unit 212e. ing.

  The various information setting unit 212a sets (stores) various information input to the input unit 211 as data in the storage unit 213. “Various information” refers to the characteristics of materials such as the density and elasticity of rubber and cords provided in the tire, the characteristics of the tire such as the properties and rigidity of the material, the amount of strain, the tire shape and structure, and the tread pattern. Design data, information including at least one of displacement or velocity applied to the bead core, acceleration, rotational displacement, angular velocity, angular acceleration, and force.

  The tire model creation unit 212b creates a tire model 100 obtained by modeling a tire with a finite number of elements based on data (various information) set by the various information setting unit 212a.

  The “element” indicates a region when a structure such as the tire model 100 is divided into a large number of regions with a finite size, and the above-described various pieces of information are associated with each other. For example, each element includes a two-dimensional triangular / tetragonal membrane element and the like, and a three-dimensional tetrahedral / pentahedral / hexahedral solid element.

  Here, in the tire model 100, the cross-sectional model 10 (not shown in FIG. 1, refer to FIG. 3) which is a cross-section in the width direction of the tire model 100 corresponding to the cross-section in the width direction of the tire is the tire diameter of one bead core in the tire. The shape corresponds to the position P on the outer side in the tire radial direction of the other bead core via the side wall SW and the tread portion TR. That is, the shape corresponding to the inner side in the tire radial direction from the position P on the outer side in the tire radial direction of the bead core in the tire is omitted from the tire model 100.

  The boundary condition setting unit 212c sets (stores) the boundary condition input to the input unit 211 in the storage unit 213 as data. The “boundary conditions” include road surface conditions such as a dry road surface or a wet road surface, tire conditions such as air pressure, load, camber angle, slip angle, and speed.

  The performance predicting unit 212d uses the finite element method (FEM) to simulate the tire model 100 created by the tire model creating unit 212b, and predicts the performance of the tire model 100 (hereinafter referred to as tire performance).

  The “finite element method (FEM)” is a method for analyzing the entire system (tire model 100) by associating various information with the above-described elements. “Tire performance” refers to overall performance such as running performance, handling stability, riding comfort, and crack resistance.

  The result output unit 212e outputs an instruction (signal) for causing the display unit 214 to display the prediction result of the tire performance predicted by the performance prediction unit 212d.

  The storage unit 213 stores various information and boundary conditions input to the input unit 211, that is, data of various information set by the various information setting unit 212a and boundary condition data set by the boundary condition setting unit 212c. .

  The display unit 214 displays the performance of the tire according to the instruction to display the prediction result of the performance of the tire from the result output unit 212e. The display unit 214 can display various information and boundary conditions input by the input unit 211.

  The program storage unit 215 is a storage medium that stores a tire model 100 creation program for causing the processing unit 212 to execute a complex replacement process or the like. For example, examples of the storage medium include a RAM, a hard disk, a flexible disk, a compact disk, an IC chip, and a cassette tape. According to the recording medium holding such a program, the program can be easily held, transported, sold, and the like.

  In the present embodiment, the various information setting unit 212a and the boundary condition setting unit 212c have been described separately. However, the information setting unit 212a and the boundary condition setting unit 212c are the same setting unit. There may be.

(Tire performance prediction method)
Next, a tire performance prediction method will be described with reference to FIG. FIG. 2 is a flowchart showing a tire performance prediction method in the present embodiment.

  As shown in FIG. 2, first, in step 10, the processing unit 212 (various information setting unit 212 a) performs processing for setting (storing) various information input to the input unit 211 as data in the storage unit 213.

  Next, in step 20, the processing unit 212 (tire model creation unit 212b) creates the tire model 100 in which the tire is modeled with a finite number of elements based on the data (various information) set in step 10. Process.

  Specifically, as shown in FIG. 3, first, the processing unit 212 has a tire model 100 (in FIG. 3) corresponding to a cross section in the tire width direction by a finite number of elements (elements 10 a, 10 b, 10 c...). Is a cross-sectional model 10 that is a cross-section in the width direction (not shown, see FIG. 4).

  Here, the cross-sectional model has a shape corresponding to a position P on the outer side in the tire radial direction of one bead core in the tire from a position P on the outer side in the tire radial direction of the other bead core via the sidewall SW and the tread portion TR. is there. That is, the shape corresponding to the inner side in the tire radial direction from the position P on the outer side in the tire radial direction of the bead core in the tire is omitted from the tire model 100.

  In addition, a displacement or speed applied to a predetermined bead core, acceleration, rotational displacement, angular velocity, angular acceleration at a position P outside the tire radial direction of the bead core in the tire model 100 corresponding to a position outside the tire radial direction of the bead core in the tire. It is preferable that information including at least one of the forces is held (associated).

  Next, as illustrated in FIG. 4, the processing unit 212 creates the tire model 100 by developing the cross-sectional model 10 in the tire model circumferential direction corresponding to the tire circumferential direction in the tire. This development means that the cross-sectional model 10 is rotated in the tire model circumferential direction about the rotation axis of the tire model 100 corresponding to the rotation axis of the tire.

  Here, as shown in FIG. 5, the tire model 100 includes a tread pattern model 300 modeled with a finite number of elements (elements 300a, 300b, 300c...) At positions corresponding to the tread pattern of the tire. It is preferable. The tire model 100 preferably includes a rim model 400 modeled with a finite number of elements (elements 400a, 400b, 400c,...) At positions corresponding to the rim wheel.

  Next, in step 30, the processing unit 212 (boundary condition setting unit 212 c) performs processing for setting (storing) the boundary condition input to the input unit 211 as data in the storage unit 213.

  In the present embodiment, the order in which the processes of Step 10 to Step 30 are performed is not necessarily performed in the order of Step 10 to Step 30, and the order may be changed. Moreover, the process of step 10 and step 30 may be performed simultaneously.

  Next, in step 40, the processing unit 212 (performance prediction unit 212d) uses the finite element method (FEM) to simulate the tire model 100 created in step 20 and perform processing to predict tire performance. .

  Specifically, the processing unit 212 is based on various information and boundary conditions input to the input unit 211, that is, data of various information set in step 10 and boundary condition data set in step 30. Using the finite element method (FEM), the tire model 100 created in step 20 is simulated, and processing for predicting the tire performance is performed.

  Next, in step 50, the processing unit 212 (result output unit 212e) performs a process of outputting an instruction (signal) for displaying the prediction result of the performance of the tire model 100 predicted in step 40 on the display unit 214.

(Action / Effect)
According to the tire performance prediction device 200 and the tire performance prediction method according to the present embodiment described above, the cross-sectional model 10 includes the sidewall SW and the tread portion TR from the position P on the outer side in the tire radial direction of one bead core in the tire. The shape corresponding to the position P on the outer side in the tire radial direction of the other bead core, that is, the shape corresponding to the inner side in the tire radial direction from the position P on the outer side of the tire radial direction in the tire is omitted from the tire model 100. As a result, the time required for numerical analysis can be greatly reduced. That is, the efficiency of tire development can be improved.

  Further, since the bead core in the tire model corresponding to the bead core in the tire meshes with the rim wheel during the deformation due to the load of the tire or rolls during the simulation and works as a rigid body, the position P on the tire radial outer side of the bead core in the tire Even if the shape corresponding to the inner side in the tire radial direction is omitted from the tire model 100, the performance of the tire model, that is, the performance of the tire can be correctly predicted.

  Further, by creating the tire model 100 by developing the cross-sectional model 10 in the tire model circumferential direction corresponding to the tire circumferential direction in the tire, tire modeling, that is, the tire model 100 can be easily created. Therefore, the time required for creating the tire model 100 can be shortened. That is, the efficiency of tire development can be improved.

  Further, since the tread pattern model 300 is arranged in the tire model 100, the tire model 100 in which the tread pattern model 300 is arranged also models the outer side in the tire radial direction from the position inside the tire radial direction of the bead core in the tire. Compared to the tire model, the time required for numerical analysis can be shortened. Moreover, it is possible to predict the performance close to that of an actual tire, that is, the performance of the tire correctly, in particular, the running performance, drainage performance, snow performance, noise performance, etc. among the tire performance.

  In addition, the bead core in the tire model 100 from the position P outside the tire radial direction to the inner side in the tire radial direction meshes with the rim wheel during the simulation due to the load of the tire during the simulation and works as a rigid body. Information including at least one of displacement or velocity applied to the bead core, acceleration, rotational displacement, angular velocity, angular acceleration, and force at a position P on the tire radial direction outer side of the bead core in the tire model 100 corresponding to the position on the outer side in the tire radial direction. By holding the tire, the performance of the tire can be predicted more correctly.

  Thus, according to the present invention, it is possible to provide a tire performance prediction method and a tire performance prediction apparatus 200 that can reduce the time required for numerical calculation while maintaining the accuracy of predicting the performance of a tire.

  As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention.

  From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  Next, in order to further clarify the effect of the present invention, a simulation performed using tire models according to comparative examples and examples will be described. In the following, a flat push analysis of a tire model (see FIG. 4) according to a comparative example and an example in which no tread pattern model is arranged will be described.

  Each tire model has a size of 215 / 55R17, an internal pressure of 230 kPa, and a load of 4 kPa. Here, the flat push analysis indicates predicting the performance of the tire model when the tire model is pressed against a flat plate without rotating.

In Table 1, the structure of the tire model (bead core and tread pattern) according to Comparative Example 1 and Example 1 and the results of numerical analysis time (time required for numerical analysis) are shown.

  As shown in Table 1, in the tire model according to Comparative Example 1, elements are arranged at positions corresponding to the tire radial direction inner side from the tire radial direction outer side position of the tire bead core, and correspond to the tire tread pattern. The tread pattern model is not arranged at the position (omitted).

  Further, in the tire model according to Example 1, the shape corresponding to the tire radial inner side from the position on the tire radial outer side of the tire bead core is omitted, and the tread pattern model is arranged at a position corresponding to the tire tread pattern. Not done (omitted).

<Numerical analysis time>
The numerical analysis time of the tire model according to Comparative Example 1 when the flat pushing analysis was performed was set to “100”, and the numerical analysis time of the tire model according to Example 1 when the flat pushing analysis was performed was displayed as an index.

  As a result, since the numerical analysis time of the tire model according to Example 1 is “76”, it was found that the time required for numerical analysis can be shortened compared to the tire model according to Comparative Example 1. That is, the tire model in which the shape corresponding to the tire radial inner side from the position on the tire radial outer side of the tire bead core is omitted from the position on the tire radial outer side of the tire bead core on the position corresponding to the tire radial inner side. It was found that the time required for numerical analysis can be shortened compared to a tire model in which elements are arranged.

  6 and 7, the contact pressure distribution of the tire model according to Comparative Example 1 (FIG. 6) and the contact pressure distribution of the tire model according to Example 1 (FIG. 7) are almost the same. It turns out that the result is obtained. That is, it was found that the performance of the tire can be correctly predicted even in a tire model in which the shape corresponding to the inside in the tire radial direction from the position outside the tire radial direction of the bead core of the tire is omitted.

Next, flat push analysis of a tire model (see FIG. 5) according to a comparative example and an example in which a tread pattern is arranged will be described. Table 2 shows the structure (bead core and tread pattern) of the tire model according to Comparative Example 2 and Example 2, and the results of numerical analysis time (time required for numerical analysis).

  As shown in Table 2, in the tire model according to Comparative Example 2, the elements are arranged at positions corresponding to the inner side in the tire radial direction from the position outside the tire radial direction of the bead core of the tire, and correspond to the tread pattern of the tire. A tread pattern model is arranged at the position. Further, in the tire model according to Example 2, the shape corresponding to the tire radial inner side from the position on the tire radial inner side of the tire bead core is omitted, and the tread pattern model is arranged at a position corresponding to the tire tread pattern. Has been.

<Numerical analysis time>
The numerical analysis time of the tire model according to Comparative Example 2 when the flat pushing analysis was performed was set to “100”, and the numerical analysis time of the tire model according to Example 2 when the flat pushing analysis was performed was displayed as an index.

  As a result, since the numerical analysis time of the tire model according to Example 2 is “95”, it was found that the time required for numerical analysis can be shortened compared to the tire model according to Comparative Example 2. That is, the tire model in which the shape corresponding to the tire radial inner side from the position on the tire radial outer side of the tire bead core is omitted from the position on the tire radial outer side of the tire bead core on the position corresponding to the tire radial inner side. It was found that the time required for numerical analysis can be shortened compared to a tire model in which elements are arranged.

It is a figure showing the composition of the tire performance prediction device concerning this embodiment. It is a flowchart which shows the tire performance prediction method which concerns on this embodiment. It is a cross section in the width direction of the tire model according to the present embodiment. It is a figure which shows the tire model which concerns on this embodiment (the 1). It is a figure which shows the tire model which concerns on this embodiment (the 2). It is a figure showing the contact distribution of the tire model concerning a comparative example. It is a figure which shows the contact distribution of the tire model which concerns on an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Cross-section model, 100 ... Tire model, 200 ... Tire performance prediction apparatus, 211 ... Input part, 212 ... Processing part, 212a ... Various information setting part, 212b ... Tire model preparation part, 212c ... Boundary condition setting part, 212d ... Performance prediction unit, 212e ... result output unit, 213 ... storage unit, 214 ... display unit, 215 ... program holding unit, 300 ... tread pattern model, 400 ... rim model, 10a-10c, 300a-300c, 400a-400c ... element

Claims (5)

Creating a tire model that models a tire with a finite number of elements; and
Predicting the performance of the tire model created in step A using a finite element method,
A cross-sectional model that is a cross-section in the width direction of the tire model that corresponds to the cross-section in the width direction of the tire created in Step A includes a sidewall and a tread portion from a position on the outer side in the tire radial direction of one bead core in the tire. A method for predicting tire performance, characterized in that the shape corresponds to the position on the outer side in the tire radial direction of the other bead core. Step A includes
Creating the cross-sectional model, step A-1;
2. The tire according to claim 1, further comprising a step A- 2 of creating the tire model by developing the cross-sectional model in the tire model circumferential direction corresponding to the tire circumferential direction in the tire. Performance prediction method.   The tire performance prediction according to claim 1 or 2, wherein the tire model has a tread pattern model modeled with a finite number of elements at positions corresponding to the tread pattern of the tire. Method.   The displacement or speed, acceleration, rotational displacement, angular velocity, angular acceleration, force applied to the bead core at the position in the tire radial direction of the bead core in the tire model corresponding to the position in the tire radial direction of the bead core in the tire. The tire performance prediction method according to any one of claims 1 to 3, wherein information including at least any of the above is held. Tire model creation means for creating a tire model in which a tire is modeled by a finite number of elements;
Using a finite element method, and a performance prediction means for predicting the performance of the tire model created by the tire model creation means,
A cross-sectional model that is a cross-section in the width direction of the tire model corresponding to a cross-section in the width direction of the tire created by the tire model creation means is a sidewall and a tread from a position on the tire radial direction outside of one bead core in the tire. The tire performance prediction device, characterized by having a shape corresponding to the position on the other side of the other bead core in the tire radial direction via the portion.