JP2018202727A - Creation method of raw tire model - Google Patents

Abstract

To create a raw tire model stably.SOLUTION: A method is for preparing a raw tire model for numerical analysis of a raw tire including a bead core and a carcass ply using a computer. In this creation method, flash parts 30a and 30b of carcass ply models 26A and 26B protruding outward in an axial direction from a bead core model 25 are folded back around the bead core model 25, and a turn-up step of overlapping main body portions 29a and 29b which are an inner portion of the axial direction of the bead core model 25 of the carcass ply models 26A and 26B is included. The turn-up step includes a first step of pressing a side of a bottom 35 of the flash parts 30a and 30b against a side surface on an axially outer side of the bead core model 25, and a second step of pressing the flash parts 30a and 30b towards the main body portions 29a and 29b in time series from the bottom 35 side to an outer edge 26a after the first step.SELECTED DRAWING: Figure 14

Description

  The present invention relates to a method for creating a raw tire model used for numerical analysis (computer simulation).

  The following Patent Document 1 proposes a method for creating a raw tire model for numerical analysis of a raw tire using a computer. The method of creating the following Patent Document 1 is a turn-up in which the protruding portion of the carcass ply model that protrudes outward in the axial direction from the bead core model is folded around the bead core model and overlapped with the main body portion in the axial direction of the bead core model of the carcass ply model. It includes a process.

JP 2017-027383 A

  In the turn-up process of Patent Document 1, an evenly distributed load is defined over the entire radial inner peripheral surface of the protruding portion based on the pressure of the bladder used in the actual raw tire manufacturing process. However, in such a method, there is a problem that a gap is easily generated between the base portion of the protruding portion, which is a severely bent portion, and the bead core model, and the movement of the protruding portion becomes unstable.

  The present invention has been devised in view of the actual situation as described above, and has as its main object to provide a method capable of stably producing a raw tire model.

  The present invention is a method for creating a raw tire model for numerical analysis of a raw tire including a bead core and a carcass ply using a computer, and the computer uses a finite number of elements around the tire axis. Defining a cylindrical carcass ply model; defining a bead core model so as to be mounted on the outer peripheral side of the carcass ply model at an axially inner position from an axial outer edge of the carcass ply model; A turn-up process in which the protruding portion of the carcass ply model that protrudes outward in the axial direction from the bead core model is folded around the bead core model and overlapped with the main body that is the inner portion of the carcass ply model in the axial direction of the bead core model. And the turn-up process includes a step of connecting the base side of the protruding portion to the bead. A first step of pressing against the axially outer side surface of the core model, and a second step of pressing the protruding portion toward the body portion from the root side to the outer edge in time series after the first step. It is characterized by that.

  In the production method of the raw tire model according to the present invention, the first step may be performed by pushing up a roller from a radially inner surface side of the protruding portion in a cross section including the tire shaft.

  In the method for producing a raw tire model according to the present invention, the second step moves the roller from the root side to the outer edge side along the inner peripheral surface of the protruding portion in a cross section including the tire shaft. The protrusion may be performed by pressing the protruding portion against the main body.

  In the production method of the raw tire model according to the present invention, the outer peripheral length of the roller may be 75% to 95% of the length from the root side to the outer edge along the inner peripheral surface.

  The raw tire model creation method of the present invention includes a first step of pressing a base side of the protruding portion against an axially outer side surface of the bead core model, and after the first step, the protruding portion is attached to the main body portion. And a second step of pressing in time series from the base side to the outer edge. Thus, in the method for producing a raw tire model of the present invention, the first step can prevent the occurrence of a gap between the base portion of the protruding portion, which is a severely bent portion, and the bead core model. . Further, in the method for creating a raw tire model of the present invention, the protruding portion and the main body portion can be overlapped while stably moving the protruding portion by the second step. Therefore, the raw tire model creation method of the present invention can stably create a raw tire model.

It is a perspective view which shows an example of the computer for performing the preparation method of a raw tire model. It is sectional drawing which shows an example of a raw tire. (A), (b) is sectional drawing explaining the process of shape | molding a casing. It is sectional drawing explaining the process of joining a casing and a tread ring. It is a flowchart which shows an example of the process sequence of the preparation method of a raw tire model. It is a flowchart which shows an example of the process sequence of a structural member model definition process. It is a figure which shows an example of the structural member model which comprises a casing model and a tread ring. It is a flowchart which shows an example of the process sequence of a raw tire model definition process. It is a flowchart which shows an example of the process sequence of a casing model definition process. It is a flowchart which shows an example of the process sequence of a 2nd conjugate | zygote model fixing process. It is a figure explaining the process of moving a bead core model inside a tire axial direction. It is a flowchart which shows an example of the process sequence of a turn-up process. It is a figure explaining an example of the 1st process. (A), (b) is a figure explaining an example of a 2nd process. It is a figure explaining an example of the process of fixing the 3rd zygote model. It is a flowchart which shows an example of the process sequence of a tread ring model definition process. It is a flowchart which shows an example of the process sequence of a shaping process. It is a figure explaining the process of expanding a casing model. It is a figure explaining an example of the process of transforming a tread ring model to the casing model side. It is a figure which expands and shows the bead part of the green tire model of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The raw tire model creation method of the present embodiment (hereinafter sometimes simply referred to as “creation method”) creates a raw tire model for numerical analysis of a raw tire including a bead core and a carcass ply using a computer. It is a way for.

  FIG. 1 is a perspective view showing an example of a computer 1 for executing the creation method. The computer 1 includes a main body 1a, a keyboard 1b, a mouse 1c, and a display device 1d. The main body 1a is provided with an arithmetic processing unit (CPU), a ROM, a working memory, a storage device such as a magnetic disk, and disk drive devices 1a1, 1a2. Note that a processing procedure (program) for executing the creation method of the present embodiment is stored in the storage device in advance.

  FIG. 2 is a cross-sectional view showing an example of the raw tire 2. The raw tire 2 of the present embodiment includes a bead core 5, a carcass ply 6, a belt ply 7, and a rubber member 11.

  The bead core 5 is formed by, for example, covering a spirally wound steel bead wire with rubber. The bead core 5 of the present embodiment is formed in a rectangular cross section.

  The carcass ply 6 of the present embodiment includes, on the tire equator C, an inner carcass ply 6A disposed on the inner side in the tire radial direction and an outer carcass ply 6B disposed on the outer side in the tire radial direction of the inner carcass ply 6A. Has been. The inner carcass ply 6A and the outer carcass ply 6B include main body portions 9a and 9b that extend from the tread portion 2a through the sidewall portion 2b to the bead core 5 of the bead portion 2c, and are connected to the main body portions 9a and 9b and pivot around the bead core 5. It includes protruding portions (folded portions) 10a and 10b that are folded back from the inside in the direction.

  The belt ply 7 of the present embodiment includes, on the tire equator C, an inner belt ply 7A disposed on the inner side in the tire radial direction and an outer belt ply 7B disposed on the outer side in the tire radial direction of the inner belt ply 7A. Has been. The inner belt ply 7A and the outer belt ply 7B are arranged on the outer side in the tire radial direction of the carcass ply 6 (the inner carcass ply 6A and the outer carcass ply 6B) and inside the tread portion 2a. The inner belt ply 7A and the outer belt ply 7B are provided with belt cords (not shown).

  The rubber member 11 includes a tread rubber 11a, a side wall rubber 11b, a clinch rubber 11c, a bead apex rubber 11d, an inner liner rubber 11e, a chafer rubber 11f, and a side reinforcing rubber 11g.

  Next, a method for forming the raw tire 2 (hereinafter, simply referred to as “forming method”) will be described. FIGS. 3A and 3B are cross-sectional views illustrating a process of forming the casing 13. FIG. 4 is a cross-sectional view illustrating a process of joining the casing 13 and the tread ring 14 together.

  As shown in FIG. 3A, in the molding method of the present embodiment, first, the first joined body 13A and the second joined body 13B are formed on a cylindrical drum (not shown) as in the conventional molding method. The third joined body 13C is wound around the tire axis and joined together. Thereby, as shown in FIG. 3B, a cylindrical casing 13 is formed.

  As shown in FIG. 3A, the first joined body 13A includes an unvulcanized inner liner rubber 11e, an unvulcanized chafer rubber 11f, and a carcass ply 6 (inner carcass ply 6A and The outer carcass ply 6B) and the side reinforcing rubber 11g are joined. The second joined body 13B is obtained by joining the bead core 5 and the unvulcanized bead apex rubber 11d. The third bonded body 13C is formed by bonding an unvulcanized clinch rubber 11c and an unvulcanized sidewall rubber 11b.

  In the step of forming the casing 13, first, the bead core 5 of the second bonded body 13 </ b> B is disposed on the outer peripheral side of the carcass ply 6 at a position on the inner side in the axial direction with respect to the axial outer edge 6 o of the carcass ply 6 of the first bonded body 13 </ b> A. Is installed. Next, the side reinforcing rubber 11 g, the inner liner rubber 11 e, and the carcass plies 6 </ b> A and 6 </ b> B arranged on the inner side in the axial direction from the bead core 5 are raised to the outer side in the tire radial direction from the bead core 5. The raising of these members can be performed by expanding a segment (not shown) of the forming drum outward in the tire radial direction. By raising these members, the bead core 5 can be moved inward in the axial direction. Then, the protruding portions 10a and 10b of the carcass plies 6A and 6B that protrude outward in the axial direction from the bead core 5 are folded around the bead core 5 by a bladder or the like (not shown). Thereby, in this embodiment, the protrusion part 10a of the inner side carcass ply 6A is overlapped on the main body part 9b which is the inner part in the axial direction of the bead core 5 of the outer side carcass ply 6B, as shown in FIG. The first joined body 13A and the second joined body 13B are joined.

  Next, in the step of forming the casing, the third joined body 13C is joined to the integrated body of the first joined body 13A and the second joined body 13B. In this step, the third joined body 13C is joined to the radially outer side of the protruding portion 10a of the inner carcass ply 6A. Thereby, the cylindrical casing 13 is formed.

  Next, in the molding method of the present embodiment, as shown in FIG. 4, for example, an unvulcanized tread rubber 11 a and an inner belt are formed on a drum (not shown) having a larger diameter than the drum forming the casing 13. The ply 7A and the outer belt ply 7B are joined together and wound. Thereby, the cylindrical tread ring 14 is formed.

  Next, in the molding method of the present embodiment, the casing 13 is bulged (shaped) in a toroidal shape while the axial distance of the bead cores 5 and 5 is reduced by the bead holding portion 15 that holds the bead cores 5. The expansion of the casing 13 is realized, for example, by directly applying the internal pressure P1 to the inner liner rubber 11e side that forms the inner cavity surface of the casing 13. The inner peripheral surface of the tread ring 14 that has been waiting in advance on the radially outer side is attached to the outer peripheral surface of the bulged casing 13. Thereby, the green tire 2 shown in FIG. 2 is molded. The raw tire 2 is put into a vulcanization mold (not shown) and vulcanized to produce a tire (not shown).

  FIG. 5 is a flowchart illustrating an example of a processing procedure of the creation method. In the raw tire model created by the creation method of the present embodiment, only one side in the tire axial direction with respect to the tire equatorial plane Cs is modeled with respect to the meridional section of the raw tire 2 shown in FIG. The other side as well as the side may be modeled. Moreover, although the case where the raw tire model of this embodiment is a three-dimensional model which has thickness in a tire peripheral direction is illustrated, a two-dimensional model may be sufficient. In addition, about the thickness of the tire circumferential direction of a raw tire model, it can set suitably. In the present embodiment, the thickness corresponding to, for example, 0.1 to 2.0 ° (0.4 ° in the present embodiment) is set at the rotation angle about the axis of the raw tire. The raw tire model may be continuous in the tire circumferential direction based on the actual raw tire 2 (shown in FIG. 2).

  In the creation method of the present embodiment, first, the constituent members of the raw tire model in which the constituent members of the raw tire 2 are modeled on the computer 1 by a finite number of elements F (i) (i = 1, 2,...). A model is defined (component member model defining step S1). FIG. 6 is a flowchart illustrating an example of a processing procedure of the constituent member model definition step S1. FIG. 7 is a diagram illustrating an example of a component model constituting the casing model and the tread ring.

  In the component member model defining step S1 of the present embodiment, first, a cylindrical rubber member model 31 around the tire axis is defined in the computer 1 using a finite number of elements F (i) (step S11). As shown in FIGS. 3 and 4, the rubber member 11 of the present embodiment includes a tread rubber 11a, a sidewall rubber 11b, a clinch rubber 11c, a bead apex rubber 11d, an inner liner rubber 11e, a chafer rubber 11f, and a side reinforcing rubber. 11g is included. The rubber member model 31 is defined based on the cross-sectional shape including the tire shaft of each rubber member 11 with respect to the sheet-like rubber member 11 (11a to 11g) wound in a cylindrical shape around the tire shaft.

  In step S11, first, design data (for example, CAD data) of a sheet-like rubber member 11 (11a to 11g (shown in FIGS. 3 and 4)) wound around a drum (not shown) is transferred to the computer 1. Entered. The design data includes, for example, numerical data related to the contour of each rubber member 11 (11a to 11g). Next, in step S11, a two-dimensional model modeled (discretized) with a finite number of elements F (i) is set based on the design data of each rubber member 11 (11a to 11g). In step S11, these two-dimensional models are copied in the tire circumferential direction at a predetermined angular pitch and developed three-dimensionally. Thereby, a three-dimensional tread rubber model 31a, a sidewall rubber model 31b, a clinch rubber model 31c, a bead apex rubber model 31d, an inner liner rubber model 31e, a chafer rubber model 31f, and a side reinforcing rubber model 31g are set. The

  Element F (i) can be handled by a numerical analysis method. As the numerical analysis method, for example, a finite element method, a finite volume method, a difference method, or a boundary element method can be appropriately employed. In this embodiment, the finite element method is adopted.

  The element F (i) expanded three-dimensionally is defined as a three-dimensional solid element or beam element. Each element F (i) includes an element number, a node number 23, a coordinate value of the node 23, and material characteristics (for example, density, tensile rigidity, compression rigidity, shear rigidity, bending rigidity, or torsional rigidity). Etc.) is defined.

  In addition, as a material characteristic of unvulcanized rubber, for example, literature (Hiroshi Hiroma, “Large deformation behavior of unvulcanized rubber under a constant elongation rate”, Journal of the Japanese Society of Rheology, Japanese Society of Rheology, 1976) , Vol.4, p.3-9) and literature (Konio Tozaki, 3 others, “Green Strength Index, Viscoelastic Treatment of Yield Stress”, Journal of the Japan Rubber Association, Japan Rubber Association, 1969. Year, Vol. 42, No. 6, p. 433-438). In the present embodiment, the material characteristics of the unvulcanized rubber are defined based on these documents. Each rubber member model 31 (31 a to 31 g) is input to the computer 1.

  Next, in the component member model defining step S1 of the present embodiment, a cylindrical carcass ply model 26 around the tire axis is defined in the computer 1 using a finite number of elements F (i) (step S12). The carcass ply model 26 includes a sheet-like carcass ply 6 (in this embodiment, the inner carcass ply 6A and the outer carcass ply 6B shown in FIG. 3A) wound in a cylindrical shape around the tire axis. Defined based on cross-sectional shape including tire axis.

  In step S12, first, design data (for example, CAD data) of sheet-like inner carcass ply 6A and outer carcass ply 6B (shown in FIG. 3A) wound around a drum (not shown) Input to the computer 1. This design data includes, for example, numerical data relating to the arrangement of carcass cords (not shown) and the contour of topping rubber (not shown) covering the carcass cords. Next, in step S12, a two-dimensional model modeled (discretized) with a finite number of elements F (i) is set based on the design data of the inner carcass ply 6A and the outer carcass ply 6B. In step S12, the two-dimensional model is copied in the tire circumferential direction at a predetermined angular pitch and developed in three dimensions. Thereby, the three-dimensional inner carcass ply model 26A and the outer carcass ply model 26B are set.

  The element F (i) developed three-dimensionally may be the same as the element F (i) of each rubber member model 31 (31a to 31g). In this element F (i), the coordinate value of the node 23 and the material characteristics of the inner carcass ply 6A and the outer carcass ply 6B shown in FIG. 3A (including the material characteristics of the unvulcanized rubber described above) are included. Numeric data including etc. are defined. The inner carcass ply model 26 </ b> A and the outer carcass ply model 26 </ b> B are input to the computer 1.

  Next, in the component member model defining step S1 of this embodiment, a bead core model 25 modeled using a finite number of elements F (i) is defined in the computer 1 (step S13). The bead core model 25 is defined based on the cross-sectional shape including the tire axis of the bead core 5 (shown in FIG. 3A) mounted on the outer peripheral side of the carcass ply 6. In step S <b> 13, first, design data (for example, CAD data) of the bead core 5 is input to the computer 1. This design data includes, for example, numerical data related to the contour of the bead core 5. Next, in step S13, a two-dimensional model modeled (discretized) with a finite number of elements F (i) is set based on the design data of the bead core 5. In step S13, the two-dimensional model is copied in the tire circumferential direction at a predetermined angular pitch and developed in three dimensions. Thereby, the three-dimensional bead core model 25 formed in a rectangular cross section is set.

  As the element F (i) developed three-dimensionally, the same element F (i) as each of the rubber member models 31 (31a to 31g) can be adopted. In this element F (i), numerical data including the coordinate value of the node 23 and the material characteristics of the bead core shown in FIG. The bead core model 25 is input to the computer 1.

  Next, in the component member model defining step S1 of the present embodiment, a cylindrical belt ply model 27 around the tire axis is defined in the computer 1 using a finite number of elements F (i) (step S14). The belt ply model 27 includes a tire shaft of a sheet-like belt ply (in this embodiment, the inner belt ply 7A and the outer belt ply 7B shown in FIG. 4) wound in a cylindrical shape around the tire shaft. Defined based on cross-sectional shape.

  In step S14, first, design data (for example, CAD data) of the sheet-like inner belt ply 7A and outer belt ply 7B (shown in FIG. 4) wound around a drum (not shown) is transferred to the computer 1. Entered. This design data includes, for example, numerical data relating to the arrangement of belt cords (not shown) and the contour of a topping rubber (not shown) covering the belt cords. Next, in step S14, a two-dimensional model modeled (discretized) with a finite number of elements F (i) is set based on the design data of the inner belt ply 7A and the outer belt ply 7B. In step S14, the two-dimensional model is copied in the tire circumferential direction at a predetermined angular pitch and developed in three dimensions. As a result, the inner belt ply model 27A and the outer belt ply model 27B are set.

  As the element F (i) developed three-dimensionally, the same element F (i) as each of the rubber member models 31 (31a to 31g) can be adopted. In the element F (i), numerical data including the coordinate value of the node 23 and material characteristics of the inner belt ply 7A and the outer belt ply 7B (including the above-described material characteristics of the unvulcanized rubber) are defined. The The inner belt ply model 27A and the outer belt ply model 27B are input to the computer 1.

  Next, in the creation method of the present embodiment, the computer 1 combines the constituent member models to create a raw tire model 22 (raw tire model definition step S2). FIG. 8 is a flowchart showing an example of the processing procedure of the raw tire model definition step S2.

  In the raw tire model defining step S2 of the present embodiment, first, a casing model obtained by modeling the cylindrical casing 13 (shown in FIG. 3B) is set (casing model defining step S21). FIG. 9 is a flowchart showing an example of the processing procedure of the casing model definition step S21.

  In the casing model defining step S21 of the present embodiment, first, boundary conditions that define contact are set so that the outer surface of the component member model constituting the casing model is a wall (step S211). The component model constituting the casing model of the present embodiment includes a bead core model 25, an inner carcass ply model 26A, an outer carcass ply model 26B, a side wall rubber model 31b, a clinch rubber model 31c, and a bead apex rubber shown in FIG. A model 31d, an inner liner rubber model 31e, a chafer rubber model 31f, and a side reinforcing rubber model 31g. The boundary condition defining contact is to prevent the models from slipping through each other even if they contact each other. The boundary condition is input to the computer 1.

  Next, in the casing model defining step S21 of the present embodiment, a first joined body model 43A that models the first joined body 13A (shown in FIG. 3A) is set (step S212). As shown in FIG. 7, in step S212 of the present embodiment, for example, based on the design data of the first joined body 13A (shown in FIG. 3A), the inner carcass ply model 26A and the outer carcass ply model 26B. An inner liner rubber model 31e, a chafer rubber model 31f, and a side reinforcing rubber model 31g are disposed. Then, in step S212, the element F between the models at each joint surface of the inner carcass ply model 26A, the outer carcass ply model 26B, the inner liner rubber model 31e, the chafer rubber model 31f, and the side reinforcing rubber model 31g. The element F (i) is redefined so that the nodes 23 of i) are shared with each other. Thereby, the 1st joined body model 43A which combined each model integrally without a gap is set up. The first joined body model 43 </ b> A is input to the computer 1.

  Next, in the casing model defining step S21 of the present embodiment, a second joined body model 43B obtained by modeling the second joined body 13B (shown in FIG. 3A) is set (step S213). In step S213 of the present embodiment, for example, the bead core model 25 and the bead apex rubber model 31d are arranged based on the design data of the second joined body 13B (shown in FIG. 3A). In step S213, the element F (i) is redefined so that the nodes 23 of the elements F (i) are shared with each other on the joint surface between the bead core model 25 and the bead apex rubber model 31d. Thereby, the 2nd conjugate | zygote model 43B which couple | bonded the bead core model 25 and the bead apex rubber model 31d integrally without gap is set. The second joined body model 43B is input to the computer 1.

  Next, in the casing model defining step S21 of the present embodiment, a third joined body model 43C obtained by modeling the third joined body 13C (shown in FIG. 3A) is set (step S214). In step S214 of the present embodiment, for example, the sidewall rubber model 31b and the clinch rubber model 31c are arranged based on the design data of the third joined body 13C (shown in FIG. 3A). In step S214, the element F (i) is redefined so that the nodes 23 of the elements F (i) are shared with each other on the joint surfaces of the sidewall rubber model 31b and the clinch rubber model 31c. Thereby, the 3rd joined body model 43C which joined the sidewall rubber model 31b and the clinch rubber model 31c integrally without gap is set. The third joined body model 43 </ b> C is input to the computer 1.

  Next, in the casing model defining step S21 of the present embodiment, the second joined body model 43B is fixed to the first joined body model 43A (second joined body model fixing step S215). FIG. 10 is a flowchart showing an example of the processing procedure of the second joined body model fixing step S215.

  In the second joined body model fixing step S215 of the present embodiment, first, the bead core model 25 is defined so as to be mounted on the outer peripheral side of the carcass ply models 26A and 26B (step S31). As shown in FIG. 7, in step S31, first, based on the design data of the unvulcanized casing 13 (shown in FIG. 3A), the carcass ply models 26A and 26B of the first joined body model 43A are displayed. The bead core model 25 of the second joined body model 43B is mounted (arranged) on the outer peripheral side of the outer carcass ply model 26B at a position on the inner side in the axial direction from the outer edge 26o in the axial direction. In step S31, boundary conditions including a fixed condition are set in the contact region 33 where the outer carcass ply model 26B and the bead core model 25 are in contact with each other. Accordingly, the carcass ply model 26 (the inner carcass ply model 26A and the outer carcass ply model 26B) is the protruding portions 30a and 30b that protrude outward in the axial direction from the bead core model 25 and the inner portion in the axial direction of the bead core model 25. It is divided into main body portions 29a and 29b.

  The fixing condition is defined based on the adhesive force between each member of the actual raw tire 2 (shown in FIG. 2). Further, in the contact region 33 between the outer carcass ply model 26B and the bead core model 25, the node 23 of each element F (i) is not shared. Accordingly, as shown in FIGS. 2 and 3, the outer carcass ply 6B (first joined body model 43A) in the turn-up process S33 described later, as in the outer carcass ply 6B and the bead core 5 of the actual raw tire 2. And bead core 5 (second joined body model 43B) are allowed to move relative to each other.

  Next, in the second joined body model fixing step S215 of the present embodiment, the main body 29a of the side reinforcing rubber model 31g, the inner liner rubber model 31e, and the inner carcass ply model 26A that are arranged on the inner side in the axial direction than the bead core model 25. Then, the main body 29b of the outer carcass ply model 26B is raised outward in the tire radial direction, and the bead core model 25 is moved inward in the tire axial direction (step S32). FIG. 11 is a diagram illustrating a process of moving the bead core model 25 inward in the tire axial direction.

  In step S32, the side reinforcing rubber model 31g, the inner liner rubber model 31e, and the inner carcass ply model arranged on the inner side in the axial direction from the bead core model 25 while maintaining the bead core model 25 and the outer carcass ply model 26B fixed. The main body 29a of 26A and the main body 29b of the outer carcass ply model 26B are raised outward in the tire radial direction. The raising of these models can be carried out, for example, by moving (expanding) a segment model 55 that models a segment of the forming drum outward in the tire radial direction. The segment model 55 is defined as a rigid body that cannot be deformed. As a result, the bead core model 25 can be moved inward in the tire axial direction. By such deformation calculation, the shape of the first joined body model 43A approximates the shape of the first joined body 13A immediately before the protruding portions 10a and 10b of the carcass plies 6A and 6B shown in FIG. Can be made. The thickness of the segment model 55 can be set as appropriate. The thickness in the tire circumferential direction of the segment model 55 of the present embodiment is set to be larger than the thickness in the tire circumferential direction of the raw tire model. Thereby, the segment model 55 can support a raw tire model stably.

  The deformation calculation of each component member model including the side reinforcing rubber model 31g and the like is performed for a short time (unit time Tx (x = 0, 1) based on the shape and material characteristics of each element F (i) shown in FIG. , ...)) is performed every time. Such deformation calculation can be performed using commercially available finite element analysis application software such as LS-DYNA manufactured by JSOL, for example.

  Next, in the second joined body model fixing step S215 of the present embodiment, the protruding portions 30a and 30b of the carcass ply models 26A and 26B are folded back around the bead core model 25 (turn-up step S33). In the turn-up process S33 of the present embodiment, the folded over protruding portion 30a is overlapped with the main body portions 29a and 29b of the carcass ply models 26A and 26B. In the turn-up process S33, the chafer rubber model 31f is folded back together with the protruding portions 30a and 30b. FIG. 12 is a flowchart illustrating an example of a processing procedure of the turn-up process S33.

  In the turn-up process S33 of the present embodiment, first, as shown in FIG. 11, the radially inner peripheral surface 32 of the inner liner rubber model 31e and the side reinforcing rubber model 31g on the inner side in the axial direction from the bead core model 25, It is defined as immovable (step S331). In the present embodiment, the inner peripheral surface 32 in the radial direction of the inner liner rubber model 31e and the side reinforcing rubber model 31g is defined so as not to move by contact with the segment model 55. Thereby, in the turn-up process S33, even if the protruding portions 30a and 30b of the carcass ply models 26A and 26B are pressed toward the main body portions 29a and 29b, as in the casing 13 shown in FIG. The shape of the inner peripheral surface 32 of the inner liner rubber model 31e and the side reinforcing rubber model 31g can be maintained.

  Next, in the turn-up process S33 of the present embodiment, the base 35 side of the protruding portions 30a and 30b is pressed against the side surface 25s on the outer side in the axial direction of the bead core model 25 (first process S332). 1st process S332 of this embodiment is performed by pushing up the roller 51 which makes | forms a circle from the radial inner peripheral surface 37 side of the protrusion parts 30a and 30b in the cross section containing a tire shaft (illustration omitted).

  As with each component model, the roller 51 is a three-dimensional model in which a two-dimensional model modeled (discretized) with a finite number of elements G (i) is copied in the tire circumferential direction at a predetermined angular pitch. Expanded to The thickness of the roller 51 in the tire circumferential direction can be set as appropriate. The thickness of the roller 51 of this embodiment is set larger than the thickness of the raw tire model in the tire circumferential direction. Thereby, the inner peripheral surface 37 side in the radial direction of the protruding portions 30a and 30b can be pushed up stably. As the element G (i) expanded three-dimensionally, the same element G (i) of each constituent model shown in FIG. 7 can be adopted. In addition, in the element G (i), the coordinate value of the node 52 and numerical data including material characteristics as a rigid body that does not allow deformation are defined.

  The roller 51 is defined with boundary conditions defining contact so that the outer surface of each component model becomes a wall. Furthermore, slip conditions are defined for the roller 51 of the present embodiment so that the coefficient of friction with the outer surface of each component model becomes zero. Thereby, in this embodiment, each structural member model can be pressed, sliding the roller 51 smoothly on the outer surface of each structural member model. In the present embodiment, the circular roller 51 is illustrated in the front view, but the present invention is not limited to such a mode. For example, depending on the shape of each component model, for example, a roller 51 having a shape such as an ellipse can be employed. The roller 51 is stored in the computer 1.

  In the first step S332 of the present embodiment, first, the roller 51 is disposed on the radially inner side of the inner peripheral surface 37 of the protruding portions 30a and 30b. In the present embodiment, the inner end portion 51 i in the axial direction of the roller 51 is disposed on the outer side in the axial direction with respect to the side surface 25 s on the outer side in the axial direction of the bead core model 25.

  FIG. 13 is a diagram illustrating an example of the first step S332. Next, in the first step S332, the roller 51 is pushed up radially outward. Thereby, the base 35 side of the protruding portions 30 a and 30 b is lifted outward in the radial direction and folded around the bead core model 25. Then, the base 35 side of the protruding portions 30 a and 30 b is pressed against the side surface 25 s of the bead core model 25. In the first step S332 of the present embodiment, the roller 51 is moved until the radial outer peripheral surface 38 (the root 35 side) of the protruding portions 30a and 30b is pressed (contacted) to the entire region of the side surface 25s of the bead core model 25. Has been pushed up.

  Thus, in 1st process S332 of this embodiment, the base 35 side of the protrusion parts 30a and 30b can be return | folded around the bead core model 25, and can be pressed on the side surface 25s of the bead core model 25. FIG. Therefore, in the creation method of the present embodiment, for example, compared to the conventional method in which a uniform distributed load is defined over the entire inner peripheral surface 37 of the protruding portions 30a and 30b, the protruding portions 30a and It is possible to prevent a gap (not shown) from being generated between the root 35 side of 30b and the bead core model 25.

  Further, in the first step S332 of the present embodiment, since the roller 51 is used for folding the protruding portions 30a and 30b on the base 35 side, an equally distributed load is defined over the entire inner peripheral surface 37 of the protruding portions 30a and 30b. Compared to the conventional method, the base 35 side of the protruding portions 30a and 30b can be stably moved. Therefore, the creation method of the present embodiment can effectively prevent a gap (not shown) from being generated between the base 35 side of the protruding portion 30 that is a portion where bending is severe and the bead core model 25. .

  In the first step S332, as shown in FIG. 11, the distance L1 in the tire axial direction between the inner end portion 51i of the roller 51 and the side surface 25s of the bead core model 25 prior to pushing the roller 51 outward in the radial direction. Is preferably equal to the thickness W1 on the base 35 side of the component member model folded around the bead core model 25 (that is, the protruding portions 30a and 30b and the cheffer rubber model 31f). As a result, in the first step S332, as shown in FIG. 13, by simply pushing the roller 51 outward in the radial direction, it smoothly folds while maintaining the thickness of the component member model including the protruding portions 30a and 30b. Can do. Therefore, in the first step S332, since the component member model including the protruding portions 30a and 30b can be prevented from being compressed with a large force, the abnormal termination of the calculation due to element collapse or the like can be prevented.

  Next, in the turn-up process S33 of the present embodiment, after the first process S332, the protruding portions 30a and 30b of the carcass ply models 26A and 26B are directed from the root 35 side to the outer edge 26o toward the main body portions 29a and 29b. It is pressed in time series (second step S333). In the second step S333 of the present embodiment, in the cross section including the tire shaft (not shown), the roller 51 protrudes while moving from the base 35 side to the outer edge 26o side along the inner peripheral surface 37 of the protruding portions 30a and 30b. The parts 30a and 30b are pressed toward the main body parts 29a and 29b. 14A and 14B are diagrams illustrating an example of the second step S333.

  In the second step S333, between the radially outer peripheral surface 38 of the protruding portions 30a, 30b and the axially outer side surface 39 of the bead apex rubber model 31d, and between the outer peripheral surface 38 of the protruding portions 30a, 30b and the outer carcass ply. The protruding portions 30a and 30b are pressed toward the main body 29 so that no gap is formed between the model 26B and the outer peripheral surface 41 in the radial direction of the main body 29b. Further, in the second step S333, deformation calculation of the bead apex rubber model 31d is performed so that the axially inner side surface 40 of the bead apex rubber model 31d is pressed against the outer peripheral surface 41 of the main body portion 29b.

  As described above, in the second step S333 of the present embodiment, the protruding portions 30a and 30b are sequentially pressed in time series from the root 35 side to the outer edge 26o toward the main body portions 29a and 29b. Compared to the conventional method in which an evenly distributed load is defined over the entire inner peripheral surface 37 of 30b, the protrusions of the inner carcass ply model 26A are protruded while stably moving the protrusions 30a and 30b (controlling the movement). The portion 30a and the main body portion 29b of the outer carcass ply model 26B can be overlapped.

  Furthermore, in the second step S333 of the present embodiment, the roller 51 is moved from the base 35 side to the outer edge 26o side along the inner peripheral surface 37 of the protruding portions 30a and 30b, so that the protruding portion of the inner carcass ply model 26A The entire region 30a can be reliably overlapped with the main body 29b of the outer carcass ply model 26B. Therefore, in the creation method of this embodiment, the raw tire model 22 (shown in FIG. 19) can be created stably.

  In this embodiment, since the slip condition in which the friction coefficient is zero is defined between the roller 51 and the outer surface of the component member model, the roller 51 is moved along the inner peripheral surface 37 of the protruding portions 30a and 30b. Even without rolling, the roller 51 can be smoothly slid (slid) from the root 35 side toward the outer edge 26o side. Accordingly, in the second step S333, the protruding portions 30a and 30b can be stably moved while preventing wrinkles and the like caused by friction between the roller 51 and the outer surface of the component member model.

  The inner peripheral surface 32 of the inner liner rubber model 31e and the side reinforcing rubber model 31g on the inner side in the axial direction from the bead core model 25 is defined with a fixing condition for making it immovable. Under such fixing conditions, in the turn-up process S33, the casing 13 shown in FIG. 3 (b) can be obtained even when the protruding portions 30a, 30b of the carcass ply models 26A, 26B are pressed toward the main body portions 29a, 29b. Similarly to the above, it is possible to maintain the shapes of the inner surfaces of the inner liner rubber model 31e and the side reinforcing rubber model 31g.

  The outer peripheral length of the roller 51 can be set as appropriate. If the outer peripheral length of the roller 51 is small, the outer edge 26o side of the carcass ply models 26A, 26B is greatly loosened, and the adhesion between the protruding portions 30a, 30b and the chafer rubber model 31f may be calculated. In addition, when the outer peripheral length of the roller 51 is large, the protruding portions 30a and 30b pushed up by the roller 51 slide down from the roller 51 to the main body portions 29a and 29b, and wrinkles occur in the protruding portions 30a and 30b. There is. From such a viewpoint, the outer peripheral length of the roller 51 is such that the outer edges of the protrusions 30a and 30b (in this embodiment, the protrusions 30a of the inner carcass ply model 26A) extend from the root 35 along the radially inner peripheral surface 37. It is desirable to set based on a length L3 (shown in FIG. 11) up to 26o. In the present embodiment, the outer peripheral length of the roller 51 is preferably 75% or more of the length L3 of the protruding portions 30a and 30b, and preferably 95% or less. When the lengths of the protruding portions 30a and 30b are different, the length L3 is specified by the length of the longest protruding portion.

  Further, the pressure of the roller 51 to the component member model can be set as appropriate. When the pressure is small, there is a possibility that a gap is formed between the constituent member models. On the contrary, even if the pressure is large, there is a possibility that the calculation may be abnormally terminated due to element collapse or the like. From such a viewpoint, the pressure is preferably set to 0 to 10 MPa. Moreover, you may change a pressure according to the structural member model to press. For example, until overcoming the bead apex rubber model 31d (shown in FIG. 14A), for example, the pressure P2 inward in the tire axial direction is set to about 0 to 1 MPa, and the pressure P3 inward in the tire radial direction is set. Is preferably set to 0 MPa. Further, after overcoming the bead apex rubber model 31d (shown in FIG. 14 (b)), for example, the pressure P2 to the inner side in the tire axial direction is set to about 0.5 to 10 MPa, and the inner side in the tire radial direction is set. It is desirable that the pressure P3 is set to about 0 to 0.5 MPa. Note that the pressure P2 inward in the tire axial direction is set to an element G (i) disposed on the outer surface of the roller 51 in the tire axial direction. Further, the pressure P3 inward in the tire radial direction is set to the surface element G (i) of the roller 51 arranged on the outer side in the tire radial direction.

  Next, as shown in FIG. 10, in the second joined body model fixing step S215 of the present embodiment, the protruding portions 30a and 30b of the carcass ply models 26A and 26B are fixed (step S34). As shown in FIG. 14B, in step S34 of the present embodiment, the protrusions 30a and 30b and the bead apex are provided between the protrusion 30a of the inner carcass ply model 26A and the main body 29b of the outer carcass ply model 26B. Boundary conditions for preventing relative movement are set between the rubber model 31d and between the protruding portion 30b of the outer carcass ply model 26B and the bead core model 25. Accordingly, the protruding portions 30a and 30b of the carcass ply models 26A and 26B can be fixed to the main body portion 29b, the bead apex rubber model 31d, and the bead core model 25 of the outer carcass ply model 26B. Accordingly, in the second bonded body model fixing step S215, the second bonded body model 43B can be fixed to the first bonded body model 43A. The boundary condition is defined based on the adhesive force between the members of the actual raw tire 2 (shown in FIG. 2), and the node 23 (shown in FIG. 7) of each element F (i) is not shared. .

  Next, in the casing model defining step S21 of the present embodiment, the third joined body model 43C is fixed to the first joined body model 43A and the second joined body model 43B (step S216). FIG. 15 is a diagram illustrating an example of a process of fixing the third joined body model 43C.

  In step S216, first, based on the design data of the unvulcanized casing 13 (shown in FIG. 3B), the protruding portion 30a of the inner carcass ply model 26A and the outer surface of the chafer rubber model 31f are determined in advance. The third joined body model 43C is disposed at the position. Next, in step S216, an evenly distributed load w1 is defined on the outer surface of the third joined body model 43C. Thereby, the 3rd conjugate | zygote model 43C can be made to contact | abut to the protrusion part 30a of the inner side carcass ply model 26A and the outer surface of the cheffer rubber model 31f. In the present embodiment, the fixing condition is defined on the inner peripheral surface 32 of the inner liner rubber model 31e and the side reinforcing rubber model 31g on the inner side in the axial direction from the bead core model 25 (step S331). Even if the equally distributed load is not defined, the third joined body model 43C can be brought into contact.

  In step S216, there are boundary conditions that prevent relative movement between the third joined body model 43C and the protruding portion 30a of the inner carcass ply model 26A, and between the third joined body model 43C and the Cheffer rubber model 31f. Is set. Thereby, in casing model definition process S21, the casing model 43 which fixed the 3rd conjugate | zygote model 43C to the 1st conjugate | zygote model 43A and the 2nd conjugate | zygote model 43B is set. The boundary condition is defined based on the adhesive force between the members of the actual raw tire 2 (shown in FIG. 2), and the node 23 (shown in FIG. 7) of each element F (i) is not shared. . Further, the fixing condition defined on the inner peripheral surface 32 of the inner liner rubber model 31e and the side reinforcing rubber model 31g on the inner side in the axial direction from the bead core model 25 is released. The casing model 43 is input to the computer 1.

  Next, as shown in FIG. 8, the raw tire model defining step S2 of the present embodiment sets a tread ring model that models the cylindrical tread ring 14 (shown in FIG. 4) (tread ring model defining step). S22). FIG. 16 is a flowchart illustrating an example of the processing procedure of the tread ring model definition step S22.

  In the tread ring model defining step S22 of the present embodiment, first, boundary conditions defining contact are set so that the outer surface of the component member model constituting the tread ring model is a wall (step S221). The constituent member models constituting the tread ring model are the inner belt ply model 27A, the outer belt ply model 27B, and the tread rubber model 31a shown in FIG. The boundary condition is input to the computer 1.

  Next, in the tread ring model defining step S22 of the present embodiment, the constituent member models constituting the tread ring model are joined to set the tread ring model (step S222). In step S222 of the present embodiment, first, as shown in FIG. 7, based on the design data of the unvulcanized tread ring 14 (shown in FIG. 4), the inner belt ply model 27A, the outer belt ply model 27B, And the tread rubber model 31a is arrange | positioned. In step S222 of the present embodiment, each element F (i) on the joining surface between the inner belt ply model 27A and the outer belt ply model 27B and the joining surface between the outer belt ply model 27B and the tread rubber model 31a. The element F (i) is redefined such that the nodes 23 of the same are shared. As a result, a tread ring model 44 in which the inner belt ply model 27A, the outer belt ply model 27B, and the tread rubber model 31a are coupled together without a gap is set. The tread ring model 44 is input to the computer 1.

  Next, in the raw tire model defining step S2 of the present embodiment, boundary conditions defining contact between the casing model 43 and the tread ring model 44 are set (step S23). In step S23, boundary conditions defining contact are set such that the outer surface 43o (shown in FIG. 15) of the casing model 43 in the tire radial direction and the inner surface 44i of the tread ring model 44 in the tire radial direction are walls. The The boundary condition is input to the computer 1.

  Next, in the raw tire model defining step S2 of the present embodiment, the computer 1 combines the casing model 43 and the tread ring model 44 to define the raw tire model 22 (shaping step S24). In the shaping step S24, the outer surface 43o (shown in FIG. 15) of the casing model 43 and the inner surface 44i of the tread ring model 44 are combined. FIG. 17 is a flowchart illustrating an example of a processing procedure of the shaping step S24. FIG. 18 is a diagram illustrating a process of expanding the casing model 43.

  In the shaping step S24 of the present embodiment, first, the tread ring model 44 is disposed outside the casing model 43 (step S241). The radial positions of the tread ring model 44 and the casing model 43 are set based on the actual tread ring 14 and the radial position of the casing 13 before bulging shown in FIG.

  Next, in the shaping step S24 of the present embodiment, the computer 1 performs a deformation calculation that causes the casing model 43 to bulge outward in the radial direction (step S242). In step S242, first, an evenly distributed load w2 is defined on the inner surface 43i of the casing model 43. Further, in step S242, the bead portion 43b of the casing model 43 is moved inward in the tire axial direction. The tire axial distance between the bead portion 43b and the tire equator C is set based on the tire axial distance between the bead portion 13b of the bulged casing 13 and the tire equator C shown in FIG. Thereby, in process S242, the deformation | transformation calculation which bulges the casing model 43 to radial direction outer side can be implemented. Due to the swelling of the casing model 43, the outer surface 43o of the casing model 43 and the inner surface 44i of the tread ring model 44 can be brought into contact with each other. The equally distributed load w2 corresponds to the pressure of high-pressure air that causes the casing 13 shown in FIG. The node 23 (shown in FIG. 7) of each element F (i) of the tread ring model 44 is fixed so as not to move.

  Next, in the shaping step S24 of the present embodiment, after the outer surface 43o of the casing model 43 and the inner surface 44i of the tread ring model 44 are in contact, the tread ring model 44 is deformed to the casing model 43 side (step S243). FIG. 19 is a diagram illustrating an example of a process of deforming the tread ring model 44 to the casing model 43 side.

  In step S243, after the fixation of the node 23 (shown in FIG. 7) of each element F (i) of the tread ring model 44 is released, the equally distributed load w3 is defined on the outer surface 44o of the tread ring model 44. Thereby, in step S243, deformation calculation of the tread ring model 44 can be performed so that the inner surface 44i of the tread ring model 44 is along the outer surface 43o of the casing model 43. The equally distributed load w3 is set based on the pressure of a stitching roller (not shown) that presses the outer peripheral surface 14o of the tread ring 14 shown in FIG.

  Next, in the shaping step S24 of the present embodiment, boundary conditions that prevent relative movement are set on the contact surface between the outer surface 43o of the casing model 43 and the inner surface 44i of the tread ring model 44 (step S244). Such a boundary condition makes it possible to integrate the casing model 43 and the tread ring model 44 without considering sharing of the node 23 (shown in FIG. 7) of each element F (i). After the boundary condition is set, the uniform load w2 defined on the inner surface 43i of the casing model 43 and the uniform load w3 defined on the outer surface 44o of the tread ring model 44 are released. By releasing these equally distributed loads w2 and w3, a raw tire model 22 in which the casing model 43 and the tread ring model 44 are combined is defined. The raw tire model 22 is input to the computer 1. Such a raw tire model 22 is a raw tire model at the time of vulcanization using, for example, a mold model (not shown) that models a vulcanization mold or a bladder model (not shown) that models a bladder. Can be used to evaluate 22 deformations.

  As described above, according to the creation method of the present embodiment, the raw tire model 22 is created based on the actual raw tire 2 forming process shown in FIGS. 3A, 3 </ b> B, and 4. Therefore, the production method of the present embodiment can approximate the raw tire model 22 to the actual shape of the raw tire 2.

  In the turn-up process S33 of the embodiments so far, the first process S332 and the second process S333 are performed using the roller 51 shown in FIGS. 13 and 14, but the present invention is not limited to such a mode. For example, in the first step S332, the pressure is defined only on the base 35 side of the protruding portions 30a and 30b, so that the root 35 of the protruding portions 30a and 30b is applied to the side surface 25s on the outer side in the axial direction of the bead core model 25. It may be pressed. Further, in the second step S333, the pressure from the base 35 side to the outer edge 26o of the protruding portions 30a, 30b is set in time series so that the protruding portions 30a, 30b are It may be pressed toward the main body portions 29a and 29b. Such a creation method can also overlap the protrusion part 30a and the main-body part 29b, moving the protrusion parts 30a and 30b stably.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  Raw tire models having a carcass ply model and a bead core model were created according to the processing procedures shown in FIGS. 5, 6, and 8 to 10 (Examples 1 to 3, Comparative Example). In the production methods of Examples 1 to 3 and the comparative example, a turn-up process of turning the protruding portion of the carcass ply model around the bead core model was performed.

  In the turn-up process of the first to third embodiments, according to the processing procedure shown in FIG. 12, the first step of pressing the base side of the protruding portion against the side surface on the outer side in the axial direction of the bead core model, and the protruding portion after the first step The second step of pressing in time series from the root side to the outer edge toward the main body was performed. In the first step and the second step of Examples 1 to 3, circular rollers were used.

  The outer peripheral length of the roller of Example 1 was set to 85% of the length L3 from the root side to the outer edge along the inner peripheral surface of the protruding portion. The outer peripheral length of the roller of Example 2 was set to 70% of the length L3. The outer peripheral length of the roller of Example 3 was set to 100% of the length L3.

In the turn-up process of the comparative example, an evenly distributed load is defined over the entire inner peripheral surface in the radial direction of the protruding portion, so that the protruding portion is folded around the bead core model, and the axis of the bead core model of the carcass ply model It was overlaid on the body part inside the direction. The common specifications are as follows.
Tire size: 195 / 55R16
Simulation software: LS-DYNA made by JSOL

  As a result of the test, in Examples 1 to 3, it was possible to prevent the generation of a gap between the base portion of the protruding portion, which is a portion where bending is severe, and the bead core model. On the other hand, in the comparative example, as shown in FIG. 20, wrinkles occurred in the gap between the root portion of the protruding portion and the bead core model, or in the root portion.

  Moreover, in Examples 1-3, the protrusion part and the main-body part were able to be piled up, moving a protrusion part stably. On the other hand, in the comparative example, the movement of the protruding portion became unstable, and the protruding portion violently collided with the main body portion due to the magnitude of the uniformly distributed load, and the calculation ended abnormally. As described above, in the production methods of Examples 1 to 3, it was possible to stably produce the raw tire model as compared with the production method of the comparative example.

  In Example 1, since the outer peripheral length of the roller is set to 75% or more of the length L3, the adhesion between the protruding portion and the Chefer rubber model is larger than that in Comparative Example 2 set to 70%. The calculation was effectively prevented. Further, in the first embodiment, since the outer peripheral length of the roller is set to 95% or less, it is possible to effectively prevent the occurrence of wrinkles in the protruding portion compared to the third embodiment in which the roller is set to 100%. I was able to.

25 bead core model 26A carcass ply model 26B carcass ply model 26o outer edge portion 29a main body portion 29b main body portion 30a protruding portion 30b protruding portion 35 root

Claims (4)

A method for creating a raw tire model for numerical analysis of a raw tire including a bead core and a carcass ply using a computer,
Defining, in the computer, a cylindrical carcass ply model around the tire axis using a finite number of elements;
Defining a bead core model to be mounted on the outer peripheral side of the carcass ply model at a position on the inner side in the axial direction from an outer edge in the axial direction of the carcass ply model;
A turn-up process in which the protruding portion of the carcass ply model that protrudes outward in the axial direction from the bead core model is folded around the bead core model and overlapped with the main body that is the inner portion of the carcass ply model in the axial direction of the bead core model. Including
The turn-up step includes a first step of pressing a base side of the protruding portion against an axially outer side surface of the bead core model;
After the first step, the second step of pressing the protruding portion toward the main body portion in time series from the root side to the outer edge,
How to create a raw tire model.   The raw tire model creating method according to claim 1, wherein the first step is performed by pushing up a roller from a radially inner peripheral surface side of the protruding portion in a cross section including the tire shaft.   In the second step, in the cross section including the tire shaft, the protruding portion is pressed against the main body portion while moving the roller from the base side to the outer edge side along the inner peripheral surface of the protruding portion. The method for producing a raw tire model according to claim 2, wherein the method is performed.   The method for creating a raw tire model according to claim 2 or 3, wherein an outer peripheral length of the roller is 75% to 95% of a length from the base side to the outer edge along the inner peripheral surface.

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