JP4518655B2 - Tires for motorcycles - Google Patents

Description

【００８３】
なお、カーカス層は、１Ｐと２Ｐとを交差したものであり、また実施列１、２及び従来タイヤに充填されている発泡ゴムのゴム基材は同質である。
【００８４】
本試験の結果では、上記表１に示すように、実施例１及び実施例２の本発明のタイヤでは、発泡ゴムの温度は従来タイヤ（１９８℃）と比較してそれぞれ１４５℃、１３３℃に低下しており、発泡ゴムの耐熱耐久性が２００％以上向上したことが判明した。
【００８５】
【発明の効果】
本発明の二輪車用タイヤによれば、タイヤ内腔部に充填した発泡ゴムの耐熱耐久性を向上させると同時に、走行性能の低下を防止することができる。
【図面の簡単な説明】
【図１】本発明の第１実施形態に係る二輪車用タイヤの断面図である。
【図２】本発明の第１実施形態に係る二輪車用タイヤのトレッド部の展開図を示す。
【図３】本発明の第２実施形態に係る二輪車用タイヤの断面図である。
【符号の説明】
１０、５０ 二輪車用タイヤ
１６ カーカス層
１８、５２ トレッド部
２８ トレッドゴム
３０ 補強バンド層
３２ 発泡ゴム（弾性発泡体）
６２ Ｂａｓｅゴム[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motorcycle tire particularly for on-road or off-road, and more particularly to a motorcycle tire excellent in heat resistance and durability of foamed rubber filled in a tire lumen.
[0002]
[Prior art]
In general, in a tire for a motorcycle in which a tire rubber is filled with foam rubber, a tire crown region of the foam rubber is easily damaged by heat, and as a measure for improving its heat resistance and durability, a rubber base used for foam rubber is used. Means are used such as improving the heat resistance and durability of the material, or suppressing the expansion ratio that has the greatest influence on heat generation and heat storage.
[0003]
However, there is a certain limit in terms of rubber compounding technology to improve the heat resistance and durability of rubber base materials used for foamed rubber.
[0004]
On the other hand, keeping the foaming ratio low leads directly to an increase in the weight of the filler, a decrease in impact resistance, and the like, which may lead to a decrease in running performance during normal running (non-puncture).
[0005]
[Problems to be solved by the invention]
In view of the above, the present invention has an object to provide a tire for a motorcycle that can improve the heat resistance and durability of the foamed rubber filled in the tire cavity portion and at the same time prevent a decrease in running performance. And
[0006]
[Means for Solving the Problems]
The two-wheeled vehicle tire according to claim 1, wherein at least one carcass layer, a reinforcing band layer provided on the outer side in the tire radial direction of the carcass layer and dispersing an external impact force at least in the tire circumferential direction, and reinforcement A tread rubber provided on the outer side in the tire radial direction of the band, and an elastic foam having a foaming ratio of 500% or more and 1500% or less filled in a tire lumen portion on the inner side in the tire radial direction of the carcass layer, A center block row having a width of 20 to 45% of the width of the tread portion along the tire circumferential direction is provided at a substantially center in the tire axial direction of the tread portion made of the tread rubber, and the reinforcing band layer is The center block row width is 80 to 120% .
[0007]
Next, the function and effect of the motorcycle tire according to claim 1 will be described.
[0008]
A reinforcing band layer is provided on the outer side in the tire radial direction of the carcass layer, and an elastic foam having an expansion ratio of 500% to 1500% is filled in the tire lumen portion on the inner side in the tire radial direction of the carcass layer.
[0009]
Therefore, since the impact force acting on the tread rubber from the outside is dispersed in the tire circumferential direction and the like by the reinforcing band layer, the impact force received by the elastic foam in contact with the inner surface of the tire crown portion can be particularly reduced. As a result, the elastic foam The heat resistance and durability of can be improved.
[0010]
On the other hand, by filling the tire lumen with the elastic foam having the above expansion ratio, it is possible to prevent an increase in the weight of the elastic foam and at the same time prevent a decrease in impact resistance. For this reason, the fall of driving performance can be prevented.
[0011]
As a result, the heat resistance and durability of the elastic foam can be improved, and a decrease in running performance can be prevented.
[0012]
As a specific example of the elastic foam, foamed rubber is most preferable, and an elastic porous synthetic resin such as sponge may be used.
[0013]
By the way, when the expansion ratio of the elastic foam is less than 500%, the weight of the elastic foam is increased and the impact resistance is decreased. As a result, the running performance may be deteriorated, which is inappropriate.
[0014]
On the other hand, if the expansion ratio exceeds 1500%, the proportion of the air chamber portion in the elastic foam becomes too large, the partition walls between the air chambers become too thin, and the load supporting ability is lowered, which is inappropriate.
[0015]
In the present invention, the tire lumen portion refers to a space surrounded by the tire inner surface and the rim.
[0016]
Further, the expansion ratio V of the elastic foam means that the density d0 of the solid layer portion and the density d1 of the elastic foam (foamed rubber) are expressed as a percentage of (d0 / d1-1).
[0017]
In the motorcycle tire according to claim 2, the dynamic elastic modulus Eb when measured by applying a tire circumferential direction tension to the reinforcing band layer, and the dynamic modulus when measured by applying a tire circumferential direction tension to the tread rubber. The ratio Eb / Et to the elastic modulus Et is 1.05 or more.
[0018]
Next, functions and effects of the motorcycle tire according to claim 2 will be described.
[0019]
The ratio Eb / Et between the dynamic elastic modulus Eb measured by applying a tire circumferential direction tension to the reinforcing band layer and the dynamic elastic modulus Et measured by applying a tire circumferential direction tension to the tread rubber is Since it is 1.05 or more, the impact force that has acted on the tread rubber from the outside can be effectively dispersed in the tire circumferential direction and the like.
[0020]
As a result, the impact force transmitted to the elastic foam in the tire cavity can be reduced, and the heat generation amount of the elastic foam can be reduced, so that the heat resistance and durability of the elastic foam can be improved.
[0021]
On the other hand, if Eb / Et is less than 1.05, the impact force from the outside cannot be effectively dispersed in the tire circumferential direction, which is inappropriate.
[0022]
Here, the measurement conditions of the dynamic elastic modulus will be described below.
[0023]
After attaching a rubber test piece having a length of 20 mm, a width of 4.7 mm, and a thickness of 2 mm to a spectrometer (L-IR type) manufactured by Toyo Seiki Co., Ltd., an initial tension of 1.7 kgf / cm ² was applied to the rubber test piece. In this state, the rubber test piece was given a strain of 1% and a frequency of 50 Hz, and the measurement was performed at room temperature of 20 ° C.
[0024]
Further, in the tire for a motorcycle according to claim 1 , a center having a width of 20 to 45% of the width of the tread portion along the tire circumferential direction is substantially at the center in the tire axial direction of the tread portion made of tread rubber. A block row is provided, and the reinforcing band layer has a width of 80 to 120% of a center block row width.
[0025]
Next, the function and effect of the motorcycle tire according to claim 1 will be described.
[0026]
The reason why the width of the center block row is limited to 20 to 45% of the width of the tread portion is that if the width is smaller than 20%, the rigidity of the block becomes too small and the traction is lowered, which is not preferable. On the other hand, if it is greater than 45%, the traction during straight traveling is improved, but the bending rigidity of the tread becomes higher than necessary, and the riding comfort deteriorates. Moreover, the edge effect with respect to radial direction input falls (it is too far from the center until the next block of the center block), and the cornering property deteriorates, which is not preferable.
[0027]
The reason why the width of the reinforcing band layer is limited to 80 to 120% of the center block row width is that if the width is smaller than 80%, the reinforcing effect is reduced, which is not preferable. On the other hand, if it exceeds 120%, the rigidity of the tread portion becomes too large, and the steering stability is lowered, which is not preferable.
[0028]
The tread width means a dimension measured along the tire tread surface along the tire axial direction.
[0029]
In the motorcycle tire, the reinforcing band layer can be a highly elastic rubber layer containing organic fibers .
[0030]
Next, the function and effect of the motorcycle tire described above will be described.
[0031]
By making the reinforcing band layer a highly elastic rubber layer containing organic fibers, it can be effectively reinforced.
[0032]
In the motorcycle tire, the organic fiber of the high-elasticity rubber layer can be a short fiber oriented in the tire circumferential direction.
[0033]
Next, the function and effect of the motorcycle tire described above will be described.
[0034]
If the organic fiber of the high elastic rubber layer is a short fiber such as nylon, polyester, PEN, rayon, aromatic polyamide, etc., Eb / Et can be set to 1.05-1.10. Can be effectively dispersed in the tire circumferential direction and the like.
[0035]
Moreover, the tire for two-wheeled vehicles can be made into a nonwoven fabric using a short fiber .
[0036]
Next, the function and effect of the motorcycle tire described above will be described.
[0037]
If short fibers such as nylon, polyester, PEN, rayon, aromatic polyamide, etc. are used for the nonwoven fabric, Eb / Et can be 1.20 to 2.00, so the impact force from the outside is more effective. Can be dispersed in the tire circumferential direction.
[0038]
The tire for a motorcycle according to claim 3 is provided with at least one carcass layer, a reinforcing band layer that is provided outside the carcass layer in a tire radial direction, and disperses an external impact force at least in the tire circumferential direction, and the reinforcement. A tread rubber provided on the outer side in the tire radial direction of the band, and an elastic foam having a foaming ratio of 500% or more and 1500% or less filled in the tire lumen portion on the inner side in the tire radial direction of the carcass layer. The tread portion composed of the tread rubber is a Cap / Base type tread in which different types of rubber are laminated in the tire radial direction, and the center block in the tire axial direction center of the tread portion extends along the tire circumferential direction. A row is provided, and the reinforcing band layer is a Base rubber located on the inner side in the tire radial direction, the tire axial direction of the center block row And having a width of 80% to 120% of the width.
[0039]
Next, functions and effects of the motorcycle tire according to claim 3 will be described.
[0040]
The cap rubber located on the outer side in the tire radial direction is softer than the base rubber, so that the grip can be improved and the handling stability can be improved, and the base rubber is relatively hard so that the movement of the tread can be suppressed and the elastic foam filled inside the tire It can limit the fever of the body.
[0041]
In the tire for a motorcycle according to claim 4 , the tread rubber has a JIS hardness of 50 to 80 degrees.
[0042]
Next, the function and effect of the motorcycle tire according to claim 4 will be described.
[0043]
The reason why the JIS hardness of the tread rubber is limited to 50 to 80 degrees is that the rigidity of the tread portion cannot be obtained sufficiently even if the reinforcing band layer is provided if it is less than 50 degrees. Conversely, if it exceeds 80 degrees, the tread portion becomes too hard and the steering stability is impaired.
[0044]
In addition, JIS hardness means the rubber hardness measured by the spring type hardness test (A type).
[0045]
The two-wheeled vehicle tire according to claim 5 , wherein the carcass layer includes at least two carcass plies each having a carcass cord inclined by 20 ° to 60 ° with respect to the tire equator line, and the carcass cord of each of the carcass plies. Are crossing layers intersecting each other.
[0046]
Next, functions and effects of the motorcycle tire according to claim 5 will be described.
[0047]
When a radial carcass tire using a so-called radial structure carcass layer is used off-road, the tire is generally highly flat, so that the lateral rigidity is reduced and steering stability cannot be ensured.
[0048]
Therefore, steering stability can be ensured by using a so-called biased carcass layer as in the present invention.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a motorcycle tire according to a first embodiment of the present invention will be described with reference to the accompanying drawings.
[0050]
As shown in FIG. 1, a motorcycle tire 10 includes a first carcass ply 12 and a second carcass ply 14 that are rubber-coated with carcass cords that are disposed at an angle of 20 ° to 60 ° with respect to the tire equator line. A carcass layer 16 composed of two carcass plies is provided.
[0051]
Here, the carcass cord of the first carcass ply 12 and the carcass cord of the second carcass ply 14 are provided so as to cross each other.
[0052]
The carcass layer 16 reinforces the tread portion 18 and the sidewall portion 20, and both end portions thereof are wound up around the bead core 24 embedded in the bead portion 22 toward the outer side in the tire rotation axis direction.
[0053]
A carcass reinforcing layer 26 is provided outside the carcass layer 16 in the tire radial direction.
[0054]
Organic short fibers (short fiber reinforced cords) such as nylon, polyester, PEN, rayon, and aromatic polyamide extending in the tire circumferential direction between the tread rubber 28 and the outer side of the carcass reinforcing layer 26 in the tire radial direction. A reinforcing band layer 30 formed by rubber coating is provided.
[0055]
When an impact force is applied to the tread portion 18 from the outside, the reinforcing band layer 30 disperses the impact force in the tire circumferential direction or the like, thereby transmitting to the foamed rubber 32 filled in the tire lumen, which will be described later. It has a function to reduce the impact force.
[0056]
Further, the tire axial direction width SW of the reinforcing band layer 30 is 80% to 120% of the tire axial direction width BW (measured in the tire axial direction along the block surface) of the center block 28A provided in the tread portion 18. Is set to
[0057]
The tread portion 18 on the outer side in the tire radial direction of the reinforcing band layer 30 is composed of a tread rubber 28 having a JISA hardness of 50 to 80 degrees. The durability of the tread portion 18 can be improved by using the tread rubber 28 having a JISA hardness of 50 to 80 degrees.
[0058]
On the contrary, if the JIS hardness is less than 50 degrees, the block rigidity of the tread portion 18 is greatly deteriorated and the traction property is inferior, which is inappropriate. On the other hand, if the hardness exceeds 80 degrees, the block of the tread portion 18 becomes too hard and block breakage occurs. It is easy and unsuitable because there is a problem with the durability of the tread portion 18.
[0059]
As shown in FIG. 2, a block pattern is formed on the tread portion 18. In the center of the block pattern in the tire axial direction (arrow A direction in FIG. 2), there is a center block row in which a plurality of center blocks 28A are arranged at substantially equal intervals along the tire circumferential direction (arrow B direction in FIG. 2). Is formed.
[0060]
The tire axial direction width BW (the dimension measured in the tire axial direction along the block surface) of the center block 28A is set to 20% to 45% of the tire axial direction width TW of the tread portion 18.
[0061]
In addition, as shown in FIG. 1, the tire axial direction width TW of the tread portion 18 is a dimension measured in the tire axial direction along the tire tread surface.
[0062]
On the other hand, a foamed rubber 32 as an elastic foam having a foaming ratio of 500% to 1500% is filled in a tire lumen, which is a space surrounded by the tire inner surface and the rim 34. As a specific example of the elastic foam, in addition to the foamed rubber 32, an elastic porous synthetic resin such as a sponge is suitable.
[0063]
Here, the dynamic elastic modulus of the tire 10 for a motorcycle according to the present invention will be described.
[0064]
A dynamic elastic modulus Eb when measured by applying a tire circumferential direction tension to the reinforcing band layer 30 and a dynamic elastic modulus Et when measured by applying a tire circumferential direction tension to the tread rubber 28 on the ground contact side. The ratio Eb / Et is set to 1.05 or more.
[0065]
The dynamic elastic modulus was measured by attaching a rubber test piece having a length of 20 mm, a width of 4.7 mm, and a thickness of 2 mm to a spectrometer (L-IR type) manufactured by Toyo Seiki Co., Ltd. An initial tension of 1.7 kgf / cm ² is applied to the test piece, and in this state, a strain of 1% and a frequency of 50 Hz are applied to the rubber test piece, and the measurement is performed at a room temperature of 20 ° C.
[0066]
The motorcycle tire 10 of the present invention can be used for either on-road or off-road.
[0067]
Next, functions and effects of the motorcycle tire will be described.
[0068]
In conventional motorcycle tires in which foamed rubber is filled in the tire bore, the tire crown region of the foamed rubber is easily damaged by heat, and as a general measure for improving its heat resistance and durability, a rubber base material is used. Since it is difficult in terms of rubber compounding technology to improve the heat resistance durability, means such as keeping the foaming ratio of foamed rubber low have been used. However, there is a possibility that the running performance may be reduced due to an increase in the weight of the foamed rubber itself and a decrease in shock absorption.
[0069]
Therefore, as in the present invention, by providing the reinforcing band layer 30 on the outer side in the tire radial direction of the carcass layer 16, impact force from the outside is dispersed by the reinforcing band layer 30 in the tire circumferential direction and the like. The impact force received by the foamed rubber 32 in contact with the inner surface of the crown portion can be reduced. For this reason, the impact force transmitted to the foamed rubber 32 in the tire lumen can be reduced, and the heat resistance durability of the foamed rubber 32 can be improved.
[0070]
On the other hand, by filling the tire lumen with the foamed rubber 32 having the above-mentioned expansion ratio, the weight of the foamed rubber 32 can be prevented from being increased, and at the same time, the impact resistance can be prevented from being lowered. Can be prevented.
[0071]
As a result, the heat resistance and durability of the foam rubber 32 can be improved, and a decrease in running performance can be prevented.
[0072]
Here, the dynamic elastic modulus Eb when measured by applying tension in the tire circumferential direction of the reinforcing band layer 30 and the dynamic elastic modulus when measured by applying tension in the tire circumferential direction of the tread rubber 28 on the ground contact side. By setting the ratio Eb / Et to Et to be 1.05 or more, the impact force from the outside can be effectively dispersed in the tire circumferential direction and the like. As a result, the impact force transmitted to the foamed rubber 32 can be reduced, and the heat generation amount of the foamed rubber 32 can be reduced. As a result, the heat resistance and durability of the foamed rubber 32 can be improved.
[0073]
In particular, Eb / Et is set to 1.05 to 1.10. By using organic fibers of the high elastic rubber layer constituting the reinforcing band layer 30 as short fibers such as nylon, polyester, PEN, rayon, and aromatic polyamide. Therefore, the impact force from the outside can be effectively dispersed in the tire circumferential direction and the like.
[0074]
In addition, since Eb / Et can be 1.20-2.00 by using a short fiber as a nonwoven fabric, the impact force from the outside can be more effectively disperse | distributed to a tire peripheral direction.
[0075]
Next, a motorcycle tire according to the second embodiment will be described.
[0076]
In the following description, the same components as those of the two-wheeled vehicle tire 10 of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
[0077]
As shown in FIG. 3, in the motorcycle tire 50 of the present embodiment, the tread portion 52 is a Cap / Base type tread in which different types of rubber are laminated in the tire radial direction.
[0078]
Here, at the position on the inner side in the tire radial direction of the Cap rubber 60 and in the approximate center in the tire axial direction, the tire block axial width BW (the dimension measured in the tire axial direction along the surface of the block 58A) of the center block row is 80. A Base rubber 62 having a tire axial width SW of ~ 120% (a dimension measured in the tire axial direction along the surface of the Base rubber) is provided. This Base rubber 62 has the same operation and effect as the reinforcing band layer 30 in the first embodiment, and disperses the impact force from the outside in the tire circumferential direction and the like.
[0079]
According to the present invention, the steering stability can be secured by the Cap rubber 60, and the reinforcing effect can be secured by the Base rubber 62.
(Test example)
Next, a durability test was performed on a drum having a diameter of 1.7 m using the tire of the present invention and the conventional tire.
[0080]
Here, the measurement conditions are as follows: tire pressure 0 (a state in which a tire filled with an elastic body in the tire lumen is punctured), drum rotation speed (converted to the tire running speed when the vehicle is mounted) 120 Km / h, load load 190 Kg, The temperature of the foamed rubber inside the tire is measured every hour with the atmospheric temperature set to room temperature (38 ° C.). The conventional tire is not provided with a reinforcing band layer.
[0081]
Detailed measurement conditions and measurement results of this test are shown in Table 1 below.
[0082]
[Table 1]

[0083]
The carcass layer intersects 1P and 2P, and the rubber bases of foamed rubber filled in the rows 1 and 2 and the conventional tire are the same.
[0084]
In the results of this test, as shown in Table 1 above, in the tires of the present invention of Example 1 and Example 2, the temperature of the foam rubber was 145 ° C. and 133 ° C., respectively, as compared with the conventional tire (198 ° C.). It was found that the heat resistant durability of the foamed rubber was improved by 200% or more.
[0085]
【The invention's effect】
According to the motorcycle tire of the present invention, it is possible to improve the heat resistance and durability of the foamed rubber filled in the tire lumen, and at the same time, prevent a decrease in running performance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a tire for a motorcycle according to a first embodiment of the present invention.
FIG. 2 is a development view of the tread portion of the motorcycle tire according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view of a motorcycle tire according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10, 50 Two-wheeled vehicle tire 16 Carcass layer 18, 52 Tread part 28 Tread rubber 30 Reinforcement band layer 32 Foam rubber (elastic foam)
62 Base rubber

Claims (5)

At least one carcass layer;
A reinforcing band layer provided on the outer side in the tire radial direction of the carcass layer, and for dispersing an external impact force at least in the tire circumferential direction;
A tread rubber provided on the outer side in the tire radial direction of the reinforcing band;
An elastic foam having a foaming ratio of 500% or more and 1500% or less filled in a tire lumen inside the tire radial direction of the carcass layer;
Comprising
A center block row having a width of 20 to 45% of the width of the tread portion along the tire circumferential direction is provided at the approximate center in the tire axial direction of the tread portion made of the tread rubber.
The tire for motorcycles , wherein the reinforcing band layer has a width of 80 to 120% of the center block row width .   Ratio Eb / of the dynamic elastic modulus Eb measured by applying a tire circumferential tension to the reinforcing band layer and the dynamic elastic modulus Et measured by applying a tire circumferential tension to the tread rubber The tire for a motorcycle according to claim 1, wherein Et is 1.05 or more. At least one carcass layer;
A reinforcing band layer provided on the outer side in the tire radial direction of the carcass layer, and for dispersing an external impact force at least in the tire circumferential direction;
A tread rubber provided on the outer side in the tire radial direction of the reinforcing band;
An elastic foam having a foaming ratio of 500% or more and 1500% or less filled in a tire lumen inside the tire radial direction of the carcass layer;
Comprising
The tread portion composed of the tread rubber is a Cap / Base type tread in which different types of rubber are laminated in the tire radial direction,
In the center of the tread portion in the tire axial direction, a center block row is provided along the tire circumferential direction,
The tire for motorcycles , wherein the reinforcing band layer is Base rubber located on the inner side in the tire radial direction and has a width of 80 to 120% of a width in the tire axial direction of the center block row . Said tread JIS hardness of rubber, motorcycle tire according to any one of claims 1 to 3, characterized in that 50 to 80 degrees. The carcass layer includes at least two carcass plies having carcass cords inclined by 20 ° to 60 ° with respect to the tire equator line, and the carcass cords of the carcass plies are crossing layers intersecting each other. The tire for a motorcycle according to any one of claims 1 to 4 .

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