JP2006199155A - Tire model creation method, creation device and tire model creation program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire model creation method, a tire model creation device, and a tire model creation program capable of quickly creating the tire model when desiring to change the shape of the tire. <P>SOLUTION: A mesh split tread pattern 20 includes mesh split tread blocks 22A to 22K. A user can set a plurality of control points 26 respectively a profile lines of respective tread blocks while referring the tread pattern 20 displayed on a CRT. An arbitrary control point is selected among a plurality of control points 26 set to the tread block to desire to change the shape, and the selected control point 26 is moved to the desired position. The shape of the peripheral mesh is changed and the tread pattern is changed from the moving direction and moving amount of the selected control point 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tire model creation method, a tire model creation device, and a tire model creation program. More specifically, the present invention relates to a tire model creation method, a tire model creation device, and a tire model creation that analyze tire performance by a finite element method. Regarding the program.

  Conventionally, in the development of pneumatic tires, tire performance is obtained by actually designing and manufacturing tires, mounting them on automobiles, and performing performance tests. I have taken the steps of starting over.

  Recently, methods of analyzing tire performance by computer simulation have been proposed due to the development of numerical analysis methods and computer environments.

  In the numerical analysis method, a known method such as a so-called finite element method in which the entire tire including the tread portion of the tire or only the tread portion is divided into a finite number of elements for analysis can be used. In the finite element method, analysis can be performed with high accuracy by reducing the size of the element to be divided. For example, Patent Literature 1 and Patent Literature 2 disclose a tire model creation method for simulating tire performance by a finite element method.

  Conventionally, when a tire is divided into a finite number of elements (mesh division), mesh division based on CAD data is widely performed. For example, as shown in FIG. 16A, the shape of a tread pattern for one pitch based on CAD data of a tire can be divided into meshes as shown in FIG. The performance of a single tread pattern can be analyzed by a finite element method using the tread pattern model divided into meshes.

  Since the actual tire tread pattern is composed of a plurality of pitches, mesh division can be performed based on the CAD data of the plurality of pitches. FIG. 17A shows a tread pattern for five pitches based on CAD data, and FIG. 17B shows an example in which the tread pattern of FIG. The tread pattern of FIG. 16A can be created by copying CAD data for one pitch of the tread pattern of FIG. 16A on a CAD system and enlarging or reducing as necessary.

In order to divide the tread pattern of FIG. 17 (A) into meshes as shown in FIG. 17 (B), for example, CAD data of a plurality of pitches is created on the CAD system and meshed, or created on the CAD system. The mesh data may be divided after copying one pitch of CAD data to a plurality of pitches by a predetermined program, or the one pitch CAD data created on the CAD system may be divided and then copied to the plurality of pitches. At this time, it is also possible to change the pitch size of the tire in the circumferential direction. FIG. 18 shows an example in which a tire model based on CAD data for one tire is divided into meshes.
Japanese Patent No. 3314082 JP 2004-142503 A

  However, conventionally, when a tire model is created by dividing the tread pattern based on CAD data into a mesh and simulating the performance of the tire, the shape of the tire is changed and the simulation is performed again. Thus, there is a problem that it takes a long time for development because it is necessary to divide the mesh again after recreating the tread pattern.

  The present invention has been made to solve the above problems, and a tire model creation method, a tire model creation device, and a tire model creation program capable of quickly creating a tire model when it is desired to change the shape of the tire The purpose is to provide.

  In order to achieve the above object, a tire model creating method according to claim 1 is a tire model creating method for creating a tire model by dividing a tire tread pattern based on design data into a finite number of elements. Then, in conjunction with movement of some of the plurality of elements, the shape of the tread pattern is directly changed by changing the shape of surrounding elements including the element.

  According to the present invention, the tire tread pattern based on the design data is divided into a finite number of elements to create a tire model, and then the tread pattern shape is changed to recreate the tire model. Rather than changing the shape of the tread pattern by changing the data and dividing it again into multiple elements, the part of the multiple elements, that is, the movement of the element in the area whose shape is to be changed, The shape of the tread pattern is directly changed by changing the shape of surrounding elements including the element. As a result, the tire model can be re-created without changing the design data and without re-dividing the elements, so that the time required for development can be greatly reduced.

  Specifically, as described in claim 2, for example, a plurality of control points are set on the outline of the tread block included in the tread pattern, and a region whose shape is to be changed is set from the set control points. The selected control point can be selected, and the moving direction and moving amount of the selected selected control point can be input, and the shape of the tread pattern can be changed based on the moving direction and moving amount of the selected control point. .

  As described above, the shape of the tread pattern can be easily changed simply by setting the control points and moving the desired control points.

  According to a third aspect of the present invention, when a plurality of control points are associated and registered in the storage means, and one of the registered plurality of control points is selected as the selected control point, the movement of the plurality of control points is performed. The direction and the movement amount may be the same.

  Thereby, a plurality of control points can be simultaneously moved in the same direction with the same movement amount, and convenience can be improved. Further, for example, by registering all of the plurality of control points set on the outline of the tread block in association with the storage means, the tread block can be moved without changing its shape.

  Further, as described in claim 4, the selection control point may be configured to be movable in the height direction of the tread block. Thereby, a shape can be easily changed with respect to the height direction of a tread block.

  Note that, as described in claim 5, the shape can be changed by morphing. By changing the shape using morphing in this manner, it is not necessary to divide the elements again, and the tire model creation time can be greatly reduced.

  Further, as described in claim 6, design data may be created based on a tire model after changing the shape of the tread pattern. Thereby, a design change etc. can be easily performed using a CAD system etc.

  A tire model creation device according to a seventh aspect of the invention is a tire model creation device that creates a tire model by dividing a tire tread pattern based on design data into a plurality of finite elements. A change means for directly changing the shape of the tread pattern by changing the shape of a peripheral element including the element in conjunction with the movement of a part of the element is provided.

  The tire model creation program according to claim 8 is a tire model creation program for causing a computer to execute a tire model creation method for creating a tire model in which a tire tread pattern based on design data is divided into a finite number of elements. A program that includes a process of directly changing the shape of the tread pattern by changing the shape of a peripheral element including the element in conjunction with movement of a part of the plurality of elements. Features.

  As described above, according to the present invention, there is an effect that a tire model can be quickly created when it is desired to change the shape of the tire.

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

  FIG. 1 shows an outline of a personal computer for performing performance prediction of the pneumatic tire of the present invention. This personal computer is displayed on a keyboard 10 for inputting data, a computer main body 12 for predicting tire performance according to a pre-stored processing program, a CRT 14 for displaying calculation results of the computer main body 12, and the CRT. The mouse 16 is used to move the cursor to a desired position, and to select, deselect, or drag the menu item or object at the cursor position.

  The computer main body 12 includes a flexible disk unit (FDU) into which a flexible disk (FD) as a recording medium can be inserted and removed. Note that processing routines and the like described later can be read from and written to the flexible disk FD using the FDU. Therefore, a processing routine to be described later may be recorded in the FD in advance and the processing program recorded in the FD may be executed via the FDU. Further, the processing program may be stored (installed) in a mass storage device (not shown) such as a hard disk device provided in the computer main body 12 and executed. As recording media, there are optical discs such as CD-ROM and DVD-ROM, and magneto-optical discs such as MD and MO. When these are used, a CD-ROM device or DVD-ROM is used instead of or in addition to the FDU. A ROM device, MD device, MO device, or the like may be used.

  The hard disk of the computer main body 12 stores a plurality of types of tire CAD data (design data such as tire shape, structure, and material) and a tire performance analysis program described later.

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

  In step 100, the operator selects the type of tire to be analyzed. In the next step 102, CAD data of the selected tire is read from the hard disk.

  In step 104, mesh data obtained by dividing the tire shape based on the CAD data into meshes is generated in order to create a tire model for numerical analysis by the finite element method based on the CAD data read from the hard disk. This mesh division means to divide the tire into a large number of (finite) elements, and a known method can be used. Each element can be, for example, a tetrahedral element, a pentahedral element, a hexahedral element, or the like. After numerical calculation is performed for each of the divided elements and calculation is performed for all elements, an overall response can be obtained by combining all the elements. The numerical analysis method is not limited to the finite element method, and other known numerical analysis methods such as a difference method, a finite volume method, and a discrete element method (DEM) may be used.

  In the creation of the tire model in step 104, a tire cross-section model is created and then developed in the tire circumferential direction to create a three-dimensional tire model. As a creation method, a known finite element method modeling method can be used.

  As described above, when the creation of the tire model is completed, the process proceeds to step 106, and the road surface state is input together with the creation of the road surface model. In this step 106, the road surface is modeled and input to set the modeled road surface to an actual road surface state. The road surface shape is divided into elements to model the road surface, and the friction coefficient μ of the road surface is calculated. The road surface condition is input by selecting and inputting. That is, depending on the road surface condition, there is a friction coefficient μ of the road surface corresponding to a dry state, a wet state, on ice, on snow, non-paved, etc., so by selecting an appropriate value for the friction coefficient μ, the actual road surface state can be changed. Can be reproduced.

  In this way, when the road surface condition is input, the boundary condition is set in the next step 108. The boundary condition is set by applying an internal pressure, a load, a displacement, a rotational speed, a torque, or the like to the tire model, or a straight traveling speed or a road surface speed.

  In step 110, the tire deformation calculation is performed by the finite element method under the boundary condition set in step 108 to simulate tire distortion and the like.

  In step 112, a simulation result based on the tire deformation calculation in step 110, for example, the tire shape or the like is displayed on the CRT.

  In step 114, it is determined whether or not an operation for instructing the end of the simulation has been performed. If an operation for instructing the end is performed, this routine is ended. If an operation for instructing the end is not performed, the step is performed. 116.

  In step 116, it is determined whether or not an operation for instructing execution of re-simulation has been performed. If an operation for instructing execution of re-simulation has not been performed, the process proceeds to step 114.

  On the other hand, if an operation to instruct execution of re-simulation has not been performed, the process proceeds to step 118, and a mesh shape changing process as shown in FIG. 3 is performed.

  In the mesh shape changing process, first, in step 200, a control point setting process for changing the mesh shape is performed.

  Specifically, a case where a tread pattern for one pitch of a tire to be simulated is expressed in a shape as shown in FIG. 4 based on CAD data will be described.

  The tread pattern 20 shown in FIG. 4 includes tread blocks 22 </ b> A to 22 </ b> K, and groove portions 24 are formed between the tread blocks. When such a tread pattern 20 is divided into meshes by the process of step 104, as shown in FIG. 5, a tread pattern 20 in which the tread blocks 22A to 22K and the groove portions 24 are divided into meshes is obtained.

  In step 200, it is determined whether or not an operation for instructing the setting of the control point has been performed by the user. If an operation for instructing the setting of the control point has been performed, the process proceeds to step 201 to instruct the setting of the control point. If no operation has been performed, the process proceeds to step 202.

  In step 201, first, a plan view of the tread pattern 20 divided into meshes as shown in FIG. The user can set control points at nodes of any mesh existing on the outlines of the tread blocks 22A to 22K by operating the mouse 16 while referring to the tread pattern 20 displayed on the CRT 14. When the control point 26 is set, for example, a coordinate table representing the correspondence between the number of the control point 26 and the coordinates is stored in the hard disk of the computer main body 12.

  Moreover, although the example which displayed the top view of the tread pattern 20 was shown in FIG. 5, it can change to other display methods, such as displaying not only this but three-dimensional like a perspective view. .

  FIG. 6 shows an example of the set control points. As shown in FIG. 6, a plurality of control points 26 indicated by black dots in the figure are set on the outlines of the tread blocks 22A to 22K.

  This control point 26 is located on the tread block contour line and represents the feature of the tread block shape, that is, the shape of one closed region formed when adjacent control points are connected by a line. Set to a position that approximates the shape of the block.

  Accordingly, as shown in FIG. 6, the rectangular tread blocks 22 </ b> A to 22 </ b> D, 22 </ b> F and 22 </ b> H to 22 </ b> K set control points 26 at the four corners of the shape. For the tread block 22E, as shown in FIG. 7, in addition to the corners of the shape, control points 26 are also set on the smooth contour line 28. The same applies to the tread block 22G.

  The control point 26 may be set by a user operation, but the shape of each of the tread blocks 22A to 22K is detected by a known feature extraction process or the like, and a plurality of contours on the detected shape are displayed. The control point 26 may be set automatically. In this case, the number of control points 26 to be set may be set to an arbitrary number.

  The user refers to the tread pattern 20 shown in FIG. 6 displayed on the CRT 14, and drags and drops an arbitrary control point with the mouse 16 among the plurality of control points 26 set in the tread block whose shape is to be changed. Can do.

  Therefore, in step 202, it is determined whether or not an operation for moving any of the control points 26 has been performed. If an operation for moving the control points 26 has been performed, the process proceeds to step 204 to move the control points 26. If no operation has been performed, the process proceeds to step 206.

  In step 204, based on the moving direction and moving amount of the moved control point 26, the shape (mesh shape) of the tread block and the adjacent groove is changed, and the changed shape is developed in the circumferential direction of the tire. Data is generated and the changed tread pattern is displayed on the CRT 14. For changing the shape of the mesh, for example, a so-called morphing technique can be applied. As morphing techniques, there are, for example, a method of changing the shape by directly defining the shape, and a method of changing the shape by defining the region divided by the domain. By applying such a morphing technique, the shape of the mesh can be changed without changing the CAD data, and the number of steps for changing the shape can be greatly reduced.

  In addition, you may make it display the whole tire which expand | deployed the tread pattern after a change in the tire circumferential direction. As the control point 26 moves, the coordinate table is also updated.

  The movement of the control point 26 may be performed independently or may be associated with a plurality of control points 26 as will be described later, and the associated plurality of control points 26 may be moved in the same direction with the same movement amount.

  FIG. 8 shows a control point 26B of the tread block 22B, a control point 26D of the tread block 22D, two control points 26E of the tread block 22E, two control points 26G of the tread block 22G, a control point 26H of the tread block 22H, and a tread. A total of eight control points (indicated by large black dots in the figure) of the control points 26J of the block 22J are slightly moved independently to change the mesh shape of each tread block and the groove 24. Thus, the user can select and move an arbitrary control point 26, change the shape of the mesh around the moved control point 26, and easily change the shape of the tread block.

  Although a method of changing the mesh shape one by one is also conceivable, in this case, for example, a smooth contour line 28 as shown in FIG. 7 may be jagged, and the accuracy of simulation deteriorates. Can be considered. On the other hand, in this embodiment, a control point is set at a position representing the characteristic of the shape of the tread block, and the shape of the tread block is changed in conjunction with the movement to the control point. The shape of the tread block can be changed while the smooth contour line 28 remains smooth.

  Thus, since the shape can be changed without changing the number of elements (number of meshes) from the original tire model, the tire model is analyzed without greatly changing the analysis time determined by the number of elements. In addition, it is not necessary to change the number assigned to each element, and the performance of the tire models can be easily compared.

  If it is desired to change the shape in detail, a large number of control points may be set in the portion where the shape change is desired. Also, check the quality of each mesh by checking the Jacobian and skew of the mesh after changing the shape, the inner angle of the mesh, etc., and if necessary, recreate the mesh or poor quality The analysis accuracy may be improved by changing the mesh.

  Alternatively, CAD data may be generated based on the mesh data after changing the shape and stored in the hard disk. Thereby, a design change etc. can be easily performed using a CAD system etc.

  Next, when moving a plurality of control points 26 simultaneously, it is necessary to associate the plurality of control points 26 first.

  Therefore, in step 206, it is determined whether or not an operation for associating a plurality of control points 26 has been performed by the user's operation. If the operation has been performed, the process proceeds to step 208, and if the operation has not been performed, Control goes to step 210.

  In step 208, processing for associating a plurality of control points 26 selected by the user is performed. Specifically, for example, a correspondence table in which numbers of a plurality of control points 26 selected by the user are associated is stored in the hard disk of the computer main body 12.

  In step 210, it is determined whether or not an operation for releasing the association of the control points 26 has been performed by the user's operation. If the operation has been performed, the process proceeds to step 212. If the operation has not been performed, The process proceeds to step 214.

  In step 212, a process for releasing the association is performed. Specifically, the number of the control point 26 whose association is to be canceled is deleted from the correspondence table.

  In this way, a plurality of arbitrary control points 26 can be associated or dissociated. A plurality of control points may be associated within the same tread block, or a plurality of control points may be associated between different tread blocks. The number of control points 26 to be associated is not particularly limited.

  FIG. 9 shows an example of the shape of the tread pattern 20 when a plurality of control points 26 are associated and moved simultaneously. In FIG. 9, as indicated by the dotted frame in the figure, the control point 26A of the tread block 22A, the control point 26C of the tread block 22C, the control point 26B of the tread block 22B, the control point 26D of the tread block 22D, and the tread block 22E. Associating a total of three control points (indicated by large black dots in the figure) of the two control points 26E1, moving each of these groups slightly, and moving the control point 26E2 of the tread block 22E alone slightly, The example which changed the shape of each tread block and the mesh of the groove part 24 was shown.

  After associating the control points 26, for example, by dragging and dropping any one of the control points 26 to a desired position, the associated control points 26 can be moved simultaneously.

  In this way, the user can easily move the control points 26 in the same direction with the same movement amount by associating a plurality of control points 26 with each other.

  Basically, the mesh that is closer to the moved control point 26 is greatly affected by the movement, and the shape is greatly changed. The mesh that is farther from the moved control point 26 is less affected by the movement, and the change in the shape is smaller. However, for example, by associating all the control points 26 set in the tread block, the tread block can be moved without changing the mesh shape of the tread block. For example, by moving all four control points 26 set at the four corners of the tread block 22A in association with each other, the entire tread block 22A can be obtained without changing the shape of the tread block 22A and the shape of each mesh of the tread block 22A. It is possible to move in a direction with a desired movement amount.

  Although the case where the shape of the two-dimensional plane of the tread pattern is changed has been described above, the shape can also be changed in the height direction of the tread block. In this case, in step 201, the tread pattern 20 may be switched to be displayed in a perspective view, and the desired control point 26 may be dragged and dropped to move in the height direction. FIG. 10 shows an example in which two control points, the control point 26E1 at the tip of the tread block 22E and the control point 26G1 at the tip of the tread block 22G, are moved in the direction of arrow A, which is the height direction of the tread block. Indicated. Here, since the two control points 26E2 and 26G2 are set in the vicinity of the control points 26E1 and 26G1, respectively, the control points 26E1 and 26G1 are bent downward with these two control points as fulcrums.

  Thus, by moving an arbitrary control point in the height direction of the tread block, the shape of the tread block in the height direction, that is, the shape of the side surface of the tread block can be easily changed. The movement of the control point is the same as that in the case where the plane shape of the tread pattern is changed except that the control point is moved in the height direction.

  Then, after changing the shape of the tread block in the height direction in this way, the generation of the mesh is developed in the tread block height direction (arrow A direction) according to a predetermined condition. Thus, even when the shape is changed in the height direction of the tread block, the tire model can be easily recreated only by changing the surface shape of the tread block.

  Conventionally, for example, when creating the shape of the tread block 30 as shown in FIG. 11, a top view is created in the two-dimensional CAD system, and a model of the three-dimensional shape of the tread block is created by the three-dimensional CAD system using this data. A first method of creating and dividing a mesh, a second method of creating a model of a three-dimensional shape of a tread block using a three-dimensional CAD system, and a top view of the two-dimensional CAD system are created, and 2 A second method for dividing a mesh on a three-dimensional plane, developing mesh generation in the height direction of the tread block, and correcting the tip of the tread block to be lowered in the height direction of the tread block; and a two-dimensional CAD system A top view is created at, and the mesh is divided on a two-dimensional plane based on this, and the tip of the tread block is treaded. A fourth method to deploy mesh generation in the height direction of the tread blocks in consideration to lower the height direction of the lock, there was.

  However, the first method and the second method have a problem that it is necessary to create a tire model using a three-dimensional CAD system, and the operation is complicated and it takes time to create the tire model. In the method 3, it takes a long time to correct the tip portion of the tread block for the entire tire, and in the fourth method, the generation of the mesh is developed while considering the shape of the tip portion of the tread block for the entire tire. Had the problem of requiring a long time.

  Further, as shown in FIG. 12A, the tread block 30 is divided into meshes, control points 32 are set on the mesh, and the control points 32A at the tip of the tread block 30 are moved in the height direction of the tread block. Thus, a model in which the tip of the tread block is lowered as shown in FIG.

  However, when this is done for the entire tire, it is very time consuming. For example, when creating a tire model in which the tread pattern is symmetrical and the tread pattern including two tread blocks as shown in FIG. 12B has 60 pitches in the circumferential direction of the tire, The operation of reducing the height must be performed 120 (= 2 × 60) times.

  On the other hand, in the present embodiment, as shown in FIG. 10, for example, the control point 26E1 at the tip of the tread block 22E and the control point 26G1 at the tip of the tread block 22G are set to the height of the tread block. Since the mesh generation is automatically developed in the height direction of the tread block after moving in the direction of the arrow A, the operation of lowering the tip of the tread block need only be performed twice. Thereby, the creation time of the tire model can be significantly shortened.

  In step 214, when the user performs an operation to instruct execution of re-simulation, this routine is terminated and the process returns to step 110 shown in FIG. 2, and the tire deformation calculation is performed again. In step 112, the result is obtained. Output. On the other hand, if an operation to instruct execution of re-simulation has not been performed, the process returns to step 202 and the same processing as described above is repeated.

  As described above, in this embodiment, first, a tread pattern for one pitch is divided into meshes on a two-dimensional plane, control points are set at arbitrary positions, and the shape of the mesh is linked to the movement of the control points. By changing the shape of the tread pattern, the changed tread pattern was developed in the height direction of the tread block, and then developed in the tire circumferential direction to create a tire model. For this reason, since it is not necessary to use a three-dimensional CAD system and it is not necessary to perform the mesh division process again, the tire model creation time can be greatly reduced.

  Note that the present invention is also applicable to a case where the tread block is an AC block as described in Japanese Patent Application Laid-Open No. 2003-191718 and Japanese Patent Application Laid-Open No. 2000-71719, for example. The AC block eliminates uneven contact pressure by reducing the height of the block tread surface toward the block edge and the center of the block in the vicinity of the block edge. In addition, the wear resistance performance is improved. In the case of the AC block, it is necessary to repeat the formation and analysis of the tire model more frequently in order to obtain the optimum surface shape. However, by applying the present invention, it is possible to significantly reduce the time for creating the tire model.

  Next, examples of the present invention will be described.

  First, a tire model having a tire size of 205 / 55R16 and having 33 tread patterns 40 as shown in FIG. 13A in the circumferential direction of the tire is changed to a tread pattern 42 as shown in FIG. A case of re-creation will be described. In this example, the tire model was recreated by the following three methods.

  In the first method, as in the prior art, the shape of the tread pattern for one pitch is created by the CAD system and then divided into meshes, and a tread pattern 42 divided into meshes as shown in FIG. 13B is created. A tire model was re-created by developing this for 33 pitches in the circumferential direction of the tire.

  In the second method, as in this embodiment, control points are set on the mesh-divided tread pattern 40 shown in FIG. 13A, and the shape of the tread pattern 40 is changed by moving the control points. A tread pattern 42 shown in FIG. (B) was created, and this was developed by 33 pitches in the circumferential direction of the tire to recreate a tire model.

  In the third method, the tire model was re-created by changing the tread pattern for 33 pitches by the CAD system and dividing the mesh respectively, as in the conventional method.

  Below, the tire model creation time in each method is shown as an index with the result of the first method as 100.

表１から明らかなように、本発明に係る第２の方法によるタイヤモデルの作成時間が他の方法に比べて大幅に短いことがわかった。

As is apparent from Table 1, it was found that the tire model creation time by the second method according to the present invention was significantly shorter than other methods.

  Next, when the tread pattern 50 for one pitch shown in FIG. 14A is developed in the height direction of the tread block to create a tread pattern 53 as shown in FIG. A case where the tread pattern 60 as shown in FIG. In this example, tire models were recreated by the following four methods.

  In the tread pattern 60, as shown in FIG. 15B, the front end portion 62A of the tread block 62 and the front end portion 64A of the tread block 64 are compared with the corresponding portions of the tread pattern 52 shown in FIG. The shape is partially cut away.

  In the first method, a top view is created in a two-dimensional CAD system as in the prior art, and a model of a three-dimensional shape of a tread block is created by the three-dimensional CAD system using this data and divided into meshes. A tread pattern 60 as shown in FIG.

  In the second method, a tread pattern 60 as shown in FIG. 15B is created by creating a model of a three-dimensional shape of a tread block using a three-dimensional CAD system as in the prior art and dividing the model into meshes.

  In the third method, the tread block height of a tread pattern 50 as shown in FIG. 14A obtained by dividing the mesh on a two-dimensional plane based on the top view of the tread pattern in a two-dimensional CAD system as in the prior art. A tread pattern 60 as shown in FIG. 15B was created by expanding the generation of the mesh in the direction and modifying the tip of the tread block so as to be lowered in the height direction of the tread block.

  In the fourth method, a tip portion of a tread block is obtained with respect to a tread pattern 50 as shown in FIG. 14A obtained by dividing a mesh on a two-dimensional plane based on a top view of the tread pattern in a two-dimensional CAD system as in the prior art. The tread pattern 60 as shown in FIG. 15B was created by developing mesh generation in the tread block height direction in consideration of lowering the height in the tread block height direction.

  In the fifth method, as in the present invention, first, on the tread pattern 50 as shown in FIG. 14 (A) obtained by dividing the mesh on the two-dimensional plane based on the top view of the tread pattern in the two-dimensional CAD system. The control points are set in the same manner as shown in FIG. 6, and the tip 51A of the tread block 51 and the tip 52A of the tread block 52 are lowered in the height direction of the tread block, as shown in FIG. Creating a tread pattern 54 in which the tip 56A of the tread block 56 and the tip 58A of the tread block 58 are lowered in the height direction of the tread block, and generating meshes in the height direction of the tread block based on this. Thus, a tread pattern 60 as shown in FIG.

  Below, the tire model creation time in each method is shown as an index with the result of the first method as 100.

表２から明らかなように、本発明に係る第５の方法によるタイヤモデルの作成時間が他の方法に比べて大幅に短いことがわかった。

As is apparent from Table 2, it was found that the tire model creation time by the fifth method according to the present invention was significantly shorter than other methods.

It is the schematic of the personal computer for implementing performance prediction of a tire. It is a flowchart of the main routine of a tire performance analysis program. It is a flowchart of a mesh shape change process. It is a top view of the tread pattern for 1 pitch. It is a top view of the tread pattern after the mesh division | segmentation for 1 pitch. It is a top view of the tread pattern after the mesh division | segmentation for 1 pitch by which the control point was set. It is a top view of a part of tread pattern after the mesh division | segmentation in which the control point was set. It is a top view of the tread pattern after a mesh shape change. It is a top view of the tread pattern after a mesh shape change. It is a perspective view of the surface of the tread pattern after mesh division. It is a perspective view of a tread block. (A) is a perspective view of the tread block before the mesh shape change, and (B) is a perspective view of the tread block after the mesh shape change. (A) is a plan view of the tread pattern before changing the mesh shape, and (B) is a plan view of the tread pattern after changing the mesh shape. (A) is a perspective view of the surface of the tread pattern before the mesh shape change, (B) is a perspective view of the tread pattern before the mesh shape change. (A) is a perspective view of the surface of the tread pattern after the mesh shape change, and (B) is a perspective view of the tread pattern after the mesh shape change. (A) is a plan view of the tread pattern for one pitch, and (B) is a plan view of the tread pattern after mesh division. (A) is a plan view of a tread pattern for 5 pitches, and (B) is a plan view of the tread pattern after mesh division. It is a figure showing the whole tire after mesh division.

Explanation of symbols

10 Keyboard 12 Computer body 14 CRT
16 mice

Claims (8)

A tire model creation method for creating a tire model by dividing a tire tread pattern based on design data into a finite number of elements,
A tire model creation method, wherein the shape of the tread pattern is directly changed by changing the shape of a peripheral element including the element in conjunction with movement of a part of the plurality of elements. A plurality of control points are set on the outline of the tread block included in the tread pattern,
From the set control points, select the control points included in the area whose shape is to be changed, and input the moving direction and moving amount of the selected selected control points.
The tire model creation method according to claim 1, wherein the shape of the tread pattern is changed based on a moving direction and a moving amount of the selected control point. Register multiple control points in association with storage means,
3. The tire model creation method according to claim 2, wherein when any one of the plurality of registered control points is selected as the selected control point, the movement direction and the movement amount of the plurality of control points are made the same.   The tire model creation method according to claim 2 or 3, wherein the selected control point is movable in a height direction of the tread block.   The tire model creation method according to any one of claims 1 to 4, wherein the shape change is performed by morphing.   The tire model creation method according to any one of claims 1 to 5, wherein design data is created based on a tire model after changing a shape of the tread pattern. A tire model creation device that creates a tire model by dividing a tire tread pattern based on design data into a finite number of elements,
A change means for directly changing the shape of the tread pattern by changing the shape of a peripheral element including the element in conjunction with the movement of a part of the plurality of elements is provided. Tire model creation device. A tire model creation program for causing a computer to execute a tire model creation method for creating a tire model in which a tire tread pattern based on design data is divided into a finite number of elements,
A tire model including a process of directly changing the shape of the tread pattern by changing the shape of a peripheral element including the element in conjunction with movement of a part of the plurality of elements. Creation program.

Images