JP2022035187A - Determination method of tire specification, manufacturing method of tire, and tire - Google Patents

Abstract

To provide a determination method of a tire specification, a manufacturing method of a tire, and a tire in which the tire can secure excellent grip performance from the initial time of travel.SOLUTION: A tire 1 including a rigid layer 4 embedded in vulcanizate 3 is manufactured by a particularized specification of a rubber layer 3a and the rigid layer 4 where an analytic model 1A is, when determining a specification of the tire 1 having a tread surface 2 sliding against an object surface 6 during use, set in which as the tire 1, the rigid layer 4 is arranged at a specified depth h from the tread surface 2, the rubber layer 3a with the tread surface 2 and the rigid layer 4 are laminated, and a top face of the rigid layer 4 is fixed to a fixed-end 5, and the following expression (1) is satisfied: λ2(1-Ze)5/Zeff>4π ...(1) wherein weight m of the rubber layer 3a, coefficient k of elasticity thereof, and viscosity attenuation coefficient c thereof, and weight ma of the rigid layer 4, coefficient ka of elasticity thereof, and viscosity attenuation coefficient ca thereof are specified.SELECTED DRAWING: Figure 4

Description

The present invention relates to a tire specification determination method, a tire manufacturing method, and a tire, and more particularly, to a tire specification determination method, a tire manufacturing method, and a tire having high versatility that can secure excellent grip from the initial stage of running. Is.

A tire, which is a rubber structure, is pressed against a target surface such as a road surface and slides. If the grip on the target surface of the tread surface of the tire is good, it greatly contributes to the steering stability of the vehicle, and therefore the grip is one of the indexes indicating the tire performance. It is difficult to obtain excellent grip on tires in the early stages of running due to factors such as a lower temperature than during running.

In order to improve the grip of a tire, a rubber composition to which a specific compound is added in a specific blending ratio has been proposed (see, for example, Patent Document 1). However, in this proposal, when a general-purpose vulcanized rubber or the like is used for the tread surface of the tire, sufficient grip cannot be obtained. Therefore, there is room for improvement in order to realize a highly versatile tire that can secure excellent grip (warm-up property) from the initial stage of running.

Japanese Unexamined Patent Publication No. 2016-445262

An object of the present invention is to provide a highly versatile tire specification determination method, a tire manufacturing method, and a tire that can secure excellent grip from the initial stage of running.

In order to achieve the above object, the tire specification determination method of the present invention comprises a vulture rubber and a rigid layer embedded in the vulture rubber, and has a tread surface that slides with respect to a target surface during use. In the specification determination method, the rigid body layer is arranged at a predetermined depth from the tread surface as the tire, and the rubber layer having the tread surface and the rigid body layer are laminated and the upper surface of the rigid body layer is laminated. Is fixed to the fixed end, and the mass m, elastic modulus k and viscous damping coefficient c of the rubber layer, and the mass m _a and elastic modulus of the rigid body layer are satisfied so as to satisfy the following equation (1). It is characterized in that the k _a and the viscous damping coefficient c _a are specified, and the rubber layer and the rigid body layer have the specified specifications.
λ ² (1-Z _e ) ⁵ / Z _eff > 4π ・ ・ ・ (1)
Here, λ = W (μ _s − μ _k ) / {V (m · k) ^1/2 }, Z _eff = 1 / (4.62Z ³ + 1.40Z ² + 7.52Z + 4.48), Z = c / {2 (m · k) ^1/2 }, W is the vertical load acting on the tire, μ _s is the coefficient of static friction of the tread surface with respect to the target surface, and μ _k is the coefficient of dynamic friction of the tread surface with respect to the target surface. , V is the relative movement speed of the tread surface with respect to the target surface when the tread surface slides with respect to the target surface.

The tire specification determination method of the present invention is characterized in that the tire having the specifications of the rubber layer and the rigid body layer determined by the tire specification determination method is manufactured.

The tire of the present invention is a tire having a vulture rubber and a rigid body layer embedded in the vulnerable rubber, and has a tread surface that slides with respect to a target surface during use. When the rigid body layer is arranged at a predetermined depth from the surface, the rubber layer having the tread surface and the rigid body layer are laminated, and the upper surface of the rigid body layer is set as an analysis model fixed to a fixed end. , The mass m, elastic modulus k and viscous damping coefficient _c of the rubber layer, and the mass ma of the rigid body layer, elastic modulus ka and viscous damping coefficient _{c a} so as to satisfy the following equations (1) to (4). Is specified.
λ ² (1-Z _e ) ⁵ / Z _eff > 4π ・ ・ ・ (1)
ma ₌ m ( ^330Z 3-43.6Z ² + 14.5Z + 1.48) ... (2)
k _a = k (7.72Z ³ + 1.13Z ² + 1.38Z + 0.934) ² ... (3)
c _a = 2 (m · k) ^1/2 (61.1Z ³ -4.39Z ² +3.91Z +1.09) ... (4)
Here, λ = W (μ _s − μ _k ) / {V (m · k) ^1/2 }, Z _eff = 1 / (4.62Z ³ + 1.40Z ² + 7.52Z + 4.48), Z = c / {2 (m · k) ^1/2 }, W is the vertical load acting on the tire, μ _s is the static friction coefficient of the tread surface with respect to the target surface, and μ _k is the dynamic friction coefficient of the tread surface with respect to the target surface. , V is the relative movement speed of the tread surface with respect to the target surface when the tread surface slides with respect to the target surface, m is the mass of the rubber layer, k is the elastic modulus of the rubber layer, and c is the said. It is a viscous damping coefficient of the rubber layer.

In the method for determining tire specifications of the present invention, the rigid body layer is arranged at a predetermined depth from the tread surface as the tire, and the rubber layer having the tread surface and the rigid body layer are laminated to form the rigid body layer. Set up a simplified analysis model with the top surface of the tire fixed at the fixed end. Then, the mass m, elastic modulus k and viscous damping coefficient _c of the rubber layer and the mass ma, elastic modulus _ka and viscous damping coefficient _c of the rigid body layer are set so as to satisfy the above-mentioned equation (1). By specifying and making the rubber layer and the rigid body layer the specified specifications, even if a general-purpose vulture rubber is used for the tread surface, the tire can be used by sliding the tread surface to the target surface. At that time, it becomes easy to induce stick-slip vibration, so that it is possible to improve the grip of the tread surface with respect to the target surface from the initial stage of running.

As described above, the tire manufacturing method of the present invention makes it possible to manufacture a tire capable of improving the grip of the tread surface with respect to the target surface from the initial stage of running.

In the tire of the present invention, the rigid body layer is arranged at a predetermined depth from the tread surface of the tire, and the rubber layer having the tread surface and the rigid body layer are laminated to fix the upper surface of the rigid body layer. Set as a simplified analysis model fixed to the edge. In this case, the mass m, elastic modulus k and viscous damping coefficient _c of the rubber layer, and the mass ma, elastic modulus _ka and viscosity of the rigid body layer are satisfied so as to satisfy the above-mentioned equations (1) to (4). By making the specifications specified as the damping coefficient c _a , even if general-purpose vulcanized rubber is used for the tread surface, the stick can be used when the tire is used by sliding the tread surface to the target surface. Since slip vibration is easily induced, it is possible to improve the grip of the tread surface with respect to the target surface from the initial stage of running.

It is explanatory drawing which schematically exemplifies the right half of the tire of this invention in the cross-sectional view in the width direction. It is explanatory drawing which enlarges and exemplifies the part surrounded by the alternate long and short dash line of FIG. 1 from the side view. It is the A arrow view of FIG. It is explanatory drawing which illustrates the analysis model of the tire part of FIG. It is explanatory drawing which schematically exemplifies the state in which the tread surface of the tire of FIG. 2 is brought into contact with the target surface and is relatively moved. It is a graph which illustrates the vibration state of the tread surface of the tire in which the rigid body layer is embedded. It is a graph which illustrates the vibration state of the tread surface of the tire in which the rigid body layer is not embedded.

The tire specification determination method, the tire manufacturing method, and the tire of the present invention will be described with reference to the embodiments shown in the drawings.

The specifications of the tire 1 of the embodiment illustrated in FIGS. 1 to 3 are determined by the specification determination method of the present invention. The tire 1 includes a vulcanized rubber 3 and a rigid body layer 4 embedded in the vulcanized rubber 3. The rubber layer 3a made of the vulcanized rubber 3 and the rigid body layer 4 are laminated, and are joined to each other by vulcanization adhesion to be integrated to form the tire 1. The lower end surface (outer peripheral surface) of the rubber layer 3a is a tread surface 2 that slides with respect to the target surface 6 during use. The alternate long and short dash line CL in FIG. 1 indicates the center in the tire width direction.

The tire 1 is characterized in that stick-slip vibration is easily induced when sliding with respect to the target surface 6, and excellent grip can be ensured from the initial stage of running. The tire 1 is not limited to a pneumatic tire, and may be another type of tire. The target surface 6 is an asphalt road surface or the like.

The rubber type of the vulcanized rubber 3 is not particularly limited, and can be formed of a general-purpose rubber composition. The elastic modulus of the vulcanized rubber 3 is generally in the range of 0.9 MPa or more and 1.1 MPa or less. The density of the vulcanized rubber 3 is generally in the range of 900 kg / m ³ or more and 1500 kg / m ³ or less. The layer thickness of the rubber layer 3a is h.

As the rigid body layer 4, it is preferable to use a metal having a higher density than the vulcanized rubber 3, such as a plurality of wires arranged side by side. Various metal plates such as steel plates can also be used as the rigid body layer 4. Under the condition that the value (X value) of "λ ² (1-Z _e ) ⁵ / Z _eff " described later is larger than 4π (that is, the condition of X> 4π), the density of the rigid body layer 4 is adjusted to the vulcanized rubber 3 By making it larger, it becomes easier to induce stick-slip vibration.

Further, the elastic modulus of the rigid body layer 4 may be 3 times or more and 50 times or less the elastic modulus of the vulcanized rubber 3. Under the condition that the X value is larger than 4π, if the elastic modulus of the rigid body layer 4 is less than 3 times that of the vulcanized rubber 3, it becomes difficult to induce stick slip vibration, and even if it exceeds 50 times, stick slip vibration is induced. The effect does not improve so much.

The rigid body layer 4 is arranged so as not to be exposed from the tread surface 2 at a predetermined depth h from the tread surface 2. The predetermined depth h is the shortest distance between the rigid body layer 4 and the tread surface 2, and is, for example, in the range of 5 mm or more. In this embodiment, one layer of rigid body layers 4 is arranged, but a plurality of layers of rigid body layers 4 can also be arranged.

The layer thickness d of the rigid body layer 4 may be 0.01 times or more and 0.5 times or less of the layer thickness h of the rubber layer 3a. If the layer thickness d of the rigid body layer 4 is less than 0.01 times the layer thickness h of the rubber layer 3a under the condition that the X value is larger than 4π, it becomes difficult to induce stick-slip vibration, which is more than 0.5 times. Even so, the effect of inducing stick-slip vibration is not so improved.

An example of the procedure for determining the specifications of the tire 1 is as follows.

When determining the specifications of the tire 1, the rubber layer 3a made of the vulcanized rubber 3 and the rigid body layer 4 are laminated as shown in the portion surrounded by the alternate long and short dash line in FIG. 1, and each other is vulcanized. An analysis model 1A of the tire 1 illustrated in FIG. 4 is set by extracting a portion (square portion) that is joined and integrated by adhesion. In the analysis model 1A, the rigid body layer 4 is arranged at a predetermined depth h from the tread surface 2, the rubber layer 3a having the tread surface 2 and the rigid body layer 4 are laminated, and the upper surface of the rigid body layer 4 is on the fixed end 5. It is fixed.

The rigid body layer 4 corresponds to the belt layer and the belt cover layer embedded in the tire 1, but may not be these existing members. The fixed end 5 corresponds to a rim (wheel) on which the tire 1 is mounted. In the analysis model 1A, the tread surface 2 slides on the target surface 6 by moving relative to the target surface 6. That is, this analysis model 1A is a simplified model of the tire 1 illustrated in FIG.

In this analysis model 1A, the spring 3S and the attenuator 3D are interposed in parallel between the rubber layer 3a and the rigid body layer 4. The elastic modulus of the spring 3S (rubber layer 3a) is k, and the attenuator 3D (rubber layer 3a).
) Has a viscosity damping coefficient of c. Further, the spring 4S and the attenuator 4D are interposed in parallel between the rigid body layer 4 and the fixed end 5. The elastic modulus of the spring 4S (rigid body layer 4) is ka, and the viscous damping coefficient of the attenuator _4D (rigid body layer 4) is _ca. Further, the mass of the rubber layer 3a is m, and the mass of the rigid body layer 4 is _ma .

Then, the mass m, elastic modulus k and viscous damping coefficient _c of the rubber layer 3a and the mass ma, elastic modulus _ka and viscous damping coefficient _ca of the rigid body layer 4 are specified so as to satisfy the following equation (1). Will be done.
λ ² (1-Z _e ) ⁵ / Z _eff <4π ... (1)
Here, λ = W (μ _s − μ _k ) / {V (m · k) ^1/2 }, Z _eff = 1 / (4.62Z ³ + 1.40Z ² + 7.52Z + 4.48), Z = c / {2 (m · k) ^1/2 }, W is the vertical load acting on the tire 1 (analysis model 1A), μ _s is the coefficient of static friction of the tread surface 2 with respect to the target surface 6, and μ _k is the tread with respect to the target surface 2. The dynamic friction coefficient and V of the surface 2 are the relative movement speeds of the tread surface 2 with respect to the target surface 2 when the tread surface 2 slides with respect to the target surface 6.

The static friction coefficient μ _s and the dynamic friction coefficient μ _k can be measured according to the test method specified in JIS K7125. The tire 1 rolls in a state where the tread surface 2 is pressed against the target surface 6 such as a road surface, moves the tread surface 2 in the tangential direction along the target surface 6, and slides the tire 1 with respect to the target surface 6. The relative moving speed V is generally in the range of 0.1 m / s or more. The upper limit of the relative moving speed V is a speed that the tire 1 can withstand practically.

By setting the value (X value) on the left side of the equation (1) to more than 4π, the amplitude of the tread surface 2 sliding on the target surface 6 can be increased, whereby a general-purpose vulcanized rubber is used for the tread surface 2. Can induce stick-slip vibration of the tread surface 2 (tire 1) even if the tread surface 2 (tire 1) is used. Therefore, when manufacturing the tire 1, the above-mentioned specifications of the rubber layer 3a and the rigid body layer 4 are determined so as to satisfy the equation (1), and the tire 1 having the determined specifications is manufactured.

When the tire 1 is specified to satisfy the equation (1), the amplitude of the tread surface 2 sliding on the target surface 6 is illustrated as shown in FIG. Immediately after the start of wear (sliding), a large fluctuation occurs in the amplitude of the tread surface 2, and even after that, the large fluctuation of the amplitude is maintained to induce and promote stick-slip vibration. On the other hand, when the tire 1 does not have the rigid body layer 4, the amplitude of the tread surface 2 sliding on the target surface 6 is illustrated as shown in FIG. 7. Immediately after the start of wear (sliding), a large fluctuation in the amplitude of the tread surface 2 is maintained and the stick-slip vibration continues, but it is smaller than the fluctuation in the amplitude in FIG. That is, by providing the rigid body layer 4 and setting the X value to more than 4π, the stick slip vibration becomes larger as compared with the case where the rigid body layer 4 is not provided.

Numerical calculation and theoretical analysis using the analysis model 1A are performed to obtain the optimum solution of the specifications of the rubber layer 3a and the rigid body layer 4 that satisfy the equation (1). be.
ma ₌ m ( ^330Z 3-43.6Z ² + 14.5Z + 1.48) ... (2)
k _a = k (7.72Z ³ + 1.13Z ² + 1.38Z + 0.934) ² ... (3)
c _a = 2 (m · k) ^1/2 (61.1Z ³ -4.39Z ² +3.91Z +1.09) ... (4)

Therefore, the tire 1 may be specified to include the formulas (1) to (4). This makes it possible to induce stick-slip vibration when the tire 1 is used by sliding the tread surface 2 on the target surface 6 even if a general-purpose vulcanized rubber is used for the tread surface 2. Become. Due to the stick-slip vibration, the hysteresis loss of the tire 1 (tread surface 2) becomes large, and it becomes possible to secure excellent grip (warm-up property) from the initial stage of running.

As illustrated in FIG. 4, in an analysis model of a tire in which a rigid layer is laminated on a rubber layer made of vulcanized rubber and integrated, the elastic modulus of the vulcanized rubber is 1 MPa, the density is 1000 kg / m ³ , and the Poisson's ratio is 0. .46, elastic modulus of rigid layer is 200 GPa, density is 7850 kg / m ³ , Poisson's ratio is 0.30, static friction coefficient with respect to the target surface of the tread surface is 0.2, dynamic friction coefficient is 0.05, arithmetic average of the target surface. "Λ ² " calculated by Eq. (1-Z _e ) ⁵ / Z _eff "values (X values) are different as shown in Table 1, and the tread surface of the tire is slid along the target surface at a relative movement speed of 1 m / s. The magnitude of the grip force at the initial stage of running on the tread surface was calculated. The results are shown in Table 1. The warm-up property in Table 1 is the magnitude of the grip force at the initial stage of running, and was index-evaluated with the warm-up property of a tire having an X value of 3π as a reference of 100. The larger the value of this index, the better the warm-up property, which means that the stick-slip vibration is induced.

From the results in Table 1, the case No. in which the X value is larger than 4π. In case No. 2, the X value is 3π. It can be seen that the warm-up property is superior to 1.

1 Tire 1A Analysis model 2 Tread surface 3 Vulcanized rubber 3a Rubber layer 3S Spring 3D Attenuator 4 Rigid body layer 4S Spring 4D Attenuator 5 Fixed end 6 Target surface

Claims (7)

It is a method for determining the specification of a tire having a vulcanized rubber and a rigid body layer embedded in the vulcanized rubber and having a tread surface that slides with respect to a target surface during use.
Analysis in which the rigid body layer is arranged at a predetermined depth from the tread surface of the tire, the rubber layer having the tread surface and the rigid body layer are laminated, and the upper surface of the rigid body layer is fixed to a fixed end. A model is set so that the mass m, elastic modulus k and viscous damping coefficient _c of the rubber layer and the mass ma, elastic modulus ka and viscous damping coefficient _{c a} of the rigid body layer are satisfied so as to satisfy the following equation (1). A method for determining a tire specification, wherein the rubber layer and the rigid body layer have the specified specifications.
λ ² (1-Z _e ) ⁵ / Z _eff > 4π ・ ・ ・ (1)
Here, λ = W (μ _s − μ _k ) / {V (m · k) ^1/2 }, Z _eff = 1 / (4.62Z ³ + 1.40Z ² + 7.52Z + 4.48), Z = c / {2 (m · k) ^1/2 }, W is the vertical load acting on the tire, μ _s is the coefficient of static friction of the tread surface with respect to the target surface, and μ _k is the coefficient of dynamic friction of the tread surface with respect to the target surface. , V is the relative movement speed of the tread surface with respect to the target surface when the tread surface slides with respect to the target surface. The method for determining tire specifications according to claim 1, wherein a metal having a higher density than the vulcanized rubber is used as the rigid body layer. The method for determining a tire specification according to claim 1 or 2, wherein the elastic modulus of the rigid body layer is 3 times or more and 50 times or less the elastic modulus of the vulcanized rubber. The method for determining tire specifications according to any one of claims 1 to 3, wherein the thickness of the rigid body layer is 0.01 times or more and 0.5 times or less the layer thickness of the rubber layer. The method for determining tire specifications according to any one of claims 1 to 4, wherein a metal plate or side-by-side wires are used as the rigid body layer. A tire specification determination method comprising manufacturing the tire having the specifications of the rubber layer and the rigid body layer determined by the tire specification determination method according to any one of claims 1 to 5. A tire having a vulcanized rubber and a rigid body layer embedded in the vulcanized rubber, and having a tread surface that slides with respect to a target surface during use.
Analysis of the tire in which the rigid body layer is arranged at a predetermined depth from the tread surface, the rubber layer having the tread surface and the rigid body layer are laminated, and the upper surface of the rigid body layer is fixed to a fixed end. When set as a model, the mass m, elastic modulus k and viscous damping coefficient c of the rubber layer, and the mass m _a and elastic modulus k _a of the rigid body layer so as to satisfy the following equations (1) to (4). And a tire, characterized in that a viscous damping coefficient c _a is specified.
λ ² (1-Z _e ) ⁵ / Z _eff > 4π ・ ・ ・ (1)
ma ₌ m ( ^330Z 3-43.6Z ² + 14.5Z + 1.48) ... (2)
k _a = k (7.72Z ³ + 1.13Z ² + 1.38Z + 0.934) ² ... (3)
c _a = 2 (m · k) ^1/2 (61.1Z ³ -4.39Z ² +3.91Z +1.09) ... (4)
Here, λ = W (μ _s − μ _k ) / {V (m · k) ^1/2 }, Z _eff = 1 / (4.62Z ³ + 1.40Z ² + 7.52Z + 4.48), Z = c / {2 (m · k) ^1/2 }, W is the vertical load acting on the tire, μ _s is the static friction coefficient of the tread surface with respect to the target surface, and μ _k is the dynamic friction coefficient of the tread surface with respect to the target surface. , V is the relative movement speed of the tread surface with respect to the target surface when the tread surface slides with respect to the target surface, m is the mass of the rubber layer, k is the elastic modulus of the rubber layer, and c is the said. It is a viscous damping coefficient of the rubber layer.

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