JP3559399B2 - Radial tire - Google Patents

Description

【００４０】
【表２】

【００４１】
上記の表１，２に示されるように、本発明の適用された実施例１〜２０のタイヤは比較例のタイヤに比較してタイヤノイズが大幅に低減していることがわかる。
【００４２】
【発明の効果】
請求項１に記載のラジアルタイヤは上記構成としたので、タイヤノイズを大幅に低減できる、という優れた効果を有する。
【００４３】
また、請求項２に記載のラジアルタイヤは上記構成としたので、タイヤノイズを大幅に低減できる、という優れた効果を有する。
【図面の簡単な説明】
【図１】本発明のラジアルタイヤの第１の実施形態を示す断面図である。
【図２】図１に示すベルト補強層の一部を断面にした平面図である。
【図３】本発明のラジアルタイヤの第２の実施形態を示す断面図である。
【図４】図３に示すベルト補強層の一部を断面にした平面図である。
【図５】ベルト補強層の他の実施形態を示す斜視図である。
【符号の説明】
１０ ラジアルタイヤ
１２ ビードコア
１４ カーカス
１６ トレッド部
１８ サイドウォール部
２０ ベルト層
２２ ベルト補強層
２４ ベルト補強層
２４Ａ 第１の繊維層
２４Ｂ 第２の繊維層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radial tire, and more particularly to a radial tire in which tire noise is significantly reduced.
[0002]
[Prior art]
With the recent sophistication and quality improvement of vehicles, particularly in passenger cars, vehicle vibration and ride comfort have been rapidly improving in recent years. .
[0003]
In particular, it is desired to reduce noise transmitted to the interior of the vehicle. One of such noises is noise generated based on vibration of the tread when the tread of the tire leaves the road surface. It is known to happen.
[0004]
As a conventional tire noise reduction method, there is a method of softening rubber in a tire tread portion.
[0005]
[Problems to be solved by the invention]
However, in the method for reducing tire noise according to the above-described method, even if the tire noise can be reduced by softening the tread rubber, the wear resistance is greatly reduced, and the steering stability is also significantly deteriorated, so that it is practical. Not.
[0006]
Therefore, it is conceivable to improve the rigidity of the tread by providing a belt reinforcing layer in which the fiber direction is the circumferential direction of the tire at portions where the rigidity of the tread is low, that is, near the both ends of the belt. Further, in order to increase the rigidity, it is necessary to use a highly elastic fiber such as aramid fiber. However, since high elastic fibers usually have a direction of extremely low elongation, if high elastic fibers are used for the belt reinforcing layer, the green tire will not expand sufficiently in the vulcanization mold, and Since it does not adhere to the inner surface of the mold, there is a possibility that molding failure may occur. Therefore, in order to avoid molding defects, only low-elasticity fibers that allow elongation necessary for expansion can be used, and tire noise cannot be reduced.
[0007]
The present invention has been made in view of the above-described circumstances, and has as its object to provide a radial tire that can significantly reduce tire noise without causing a problem during tire manufacturing.
[0008]
[Means for Solving the Problems]
The present inventor has focused on the structure of the belt reinforcing layer in order to solve the above-described problems, and as a result, has found that the tire manufacturing problem and the reduction of tire noise can be satisfied at the same time, leading to the completion of the present invention. Was.
[0009]
The invention according to claim 1 includes a pair of beat portions, a toroidal carcass extending over both beat portions, a tread portion located at a crown portion of the carcass, and a belt disposed inside the tread portion. A radial tire comprising a layer and a belt reinforcing layer covering at least both end portions of the belt layer, wherein the belt reinforcing layer has a mesh structure composed of a plurality of fibers, and the fibers are formed around the tire periphery. It is characterized by being inclined with respect to the direction.
[0010]
Next, the operation of the radial tire according to claim 1 will be described.
Since the network structure is pantograph-deformable, even if the fibers have high elasticity and low cutting elongation, they can be sufficiently expanded in the longitudinal direction (tire circumferential direction). That is, since the elongation of the belt reinforcing layer itself can be increased even if the belt reinforcing layer itself is set to high elasticity, the belt reinforcing layer using high elastic fibers and having high elasticity is provided near both ends of the belt layer. By arranging, the rigidity of the tread portion near both ends of the belt layer can be increased. Thereby, vibration of the tread portion near both ends of the belt layer can be reduced, and tire noise can be reduced.
[0011]
In addition, since the belt reinforcement layer has high elongation even with high elasticity, even when using fibers with high elasticity and low elongation, the green tire can be expanded sufficiently without cutting the fibers during vulcanization molding. Therefore, molding defects do not occur.
[0012]
It is needless to say that the belt reinforcing layer can not only reduce tire noise but also improve the durability of the end portion of the belt layer.
[0013]
The invention according to claim 2 is characterized in that a pair of beat portions, a toroidal carcass extending over both beat portions, a tread portion located at a crown portion of the carcass, and a belt disposed inside the tread portion And a belt reinforcing layer that covers at least both end portions of the belt layer, wherein the belt reinforcing layer includes a plurality of fibers inclined in a predetermined direction with respect to the tire circumferential direction. A first fiber layer arranged along the direction, and a second fiber in which a plurality of fibers inclined in the opposite direction to the tire circumferential direction are arranged along the tire circumferential direction. And a fiber layer.
[0014]
Next, the operation of the radial tire according to claim 2 will be described.
In the belt reinforcing layer of the present invention, a network structure is formed by the first fiber layer and the second fiber layer. Since the reticulated structure is pantograph-deformable, it can be sufficiently expanded in the longitudinal direction (tire circumferential direction) even if the fiber has high elasticity and low cutting elongation. That is, since the elongation of the belt reinforcing layer itself can be increased even if the belt reinforcing layer itself is set to high elasticity, the belt reinforcing layer using high elastic fibers and having high elasticity is provided near both ends of the belt layer. By arranging, the rigidity of the tread portion near both ends of the belt layer can be increased. Thereby, vibration of the tread portion near both ends of the belt layer can be reduced, and tire noise can be reduced.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
As shown in FIG. 1, the radial tire 10 according to the first embodiment includes a carcass 14 that is folded around a bead core 12 from the inside to the outside of the tire and is locked, and a tread portion 16 located at a crown portion of the carcass 14. And a sidewall portion 18 of the carcass 14, at least two belt layers 20 disposed inside the tread portion 16, and a belt reinforcing layer 22 covering both end portions of the belt layer 20. Other than the above are known structures.
[0016]
As shown in FIG. 2, the belt reinforcing layer 22 is obtained by applying a rubber coating 32 to a net-like plain woven fabric in which a warp 28 and a weft 30 made of highly elastic fibers 26 are woven so as to be orthogonal to each other. It is obtained by cutting a plain woven fabric coated with the rubber coating 32 into a band shape having a constant width at 45 degrees with respect to the fiber direction. For this reason, the fiber direction is 45 degrees with respect to the tire circumferential direction (the direction of arrow A in FIG. 2).
[0017]
The fiber used for the belt reinforcing layer 22 is preferably a high elasticity fiber. Examples of the high elasticity fiber include a steel fiber, an aramid fiber, a polybenzoxazole fiber, a carbon fiber, and a glass fiber. It may be a fiber.
[0018]
Further, the fiber 26 may be a monofilant or a multifilament (or cord) in which a plurality of fibers are twisted.
[0019]
As described above, since the net-like plain woven fabric can be pantograph-deformed, even when the fiber 26 has high elasticity and low cutting elongation, the belt reinforcing layer 22 can sufficiently expand when tension is applied in the longitudinal direction (tire circumferential direction). It is in.
[0020]
That is, since the elongation of the belt reinforcing layer 22 itself can be increased even if the belt reinforcing layer 22 itself is set to high elasticity, the belt reinforcing layer 22 using high elastic fibers 26 and having high elasticity is used as the belt layer. By arranging them near both ends of the belt layer 20, the rigidity of the tread portion 16 near both ends of the belt layer 20 can be increased. Thereby, vibration of the tread portion 16 near both ends of the belt layer 20 can be reduced, and tire noise can be reduced.
[0021]
Further, since the belt reinforcing layer 22 of the present embodiment has a high elongation even if it has high elasticity, even if the fiber 26 having high elasticity and low elongation is used, the fiber 26 is cut without being cut during vulcanization molding. Since the tire can be expanded sufficiently with a margin, molding failure does not occur.
[0022]
The elastic modulus of the belt reinforcing layer 22 itself can be changed mainly by the thickness, arrangement pitch (density), and fiber direction (angle with respect to the elongation direction) of the fibers 26. It can also be changed by hardness, layer thickness, and the like.
[0023]
The elongation of the belt reinforcing layer 22 can be changed depending on the thickness of the fibers 26, the arrangement pitch (density), and the fiber direction.
[0024]
Further, in the belt reinforcing layer 22 of the present embodiment, the fibers 26 are plain-woven, but the invention is not limited to the plain weave as long as the mesh structure has at least a fiber direction inclined with respect to the tire circumferential direction.
[Second embodiment]
Next, a second embodiment of the radial tire of the present invention will be described with reference to FIGS. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0025]
As shown in FIG. 3, the belt reinforcing layer 24 of the present embodiment has a first fiber layer 24A and a second fiber layer 24B superimposed on the first fiber layer 24A.
[0026]
As shown in FIG. 4, each of the first fiber layer 24A and the second fiber layer 24B is obtained by applying a rubber coating 32 to a blind woven fabric in which a plurality of fibers 26 are woven in parallel to each other. A rubber woven fabric coated with a rubber coating 32 is cut into a band having a constant width at 45 degrees with respect to the fiber direction.
[0027]
Here, the fibers 26 of the first fiber layer 24A are inclined, for example, 45 degrees upward to the right with respect to the tire circumferential direction (the direction of arrow A in FIG. 4), and the fibers 26 of the second fiber layer 24B are It is inclined 45 degrees to the left with respect to the circumferential direction. Note that the fibers 26 of the first fiber layer 24A may be tilted to the left and the fibers 26 of the second fiber layer 24B may be tilted to the right. The belt reinforcing layer 24 may have two or more fiber layers.
[0028]
Thus, similarly to the belt reinforcing layer 22 of the first embodiment, the fiber direction of the belt reinforcing layer 24 of the present embodiment is inclined with respect to the tire circumferential direction, and the fibers 26 of the first fiber layer 24A are formed. And the fibers 26 of the second fiber layer 24B intersect with each other, so that the belt reinforcing layer 24 can be sufficiently extended in the tire circumferential direction. The raw tire can be expanded sufficiently with a margin without cutting.
[0029]
Moreover, in the vulcanized product tire, the high elastic belt reinforcement layer 24 can sufficiently increase the tread stiffness near both ends of the belt layer 20 similarly to the above-described embodiment, so that tire noise can be reduced. it can.
[0030]
In the present embodiment, the fibers 26 have good durability because they have a structure in which the fibers 26 do not contact each other.
[0031]
Although the belt reinforcing layer 24 of the present embodiment is obtained by overlapping the first fiber layer 24A and the second fiber layer 24B, the same is true without overlapping the two fiber layers. Things can be formed. For example, as shown in FIG. 5, the same thing can be obtained by applying a rubber coating 32 to a blind woven cloth so that the fibers 26 are parallel to each other, and folding it in two so that the fibers 26 intersect.
[0032]
In the above-described embodiment, the belt reinforcing layer 22 (24) is disposed on the belt layer 20 (outside in the tire radial direction) so as to cover both ends of the belt layer 20. The belt reinforcing layer 22 (24) may be disposed on the belt layer 20, or may be disposed so as to cover the entire surface of the belt layer 20.
(Test example)
In order to confirm the effect of the present invention, one kind of a tire of a comparative example and 20 kinds of tires of an example to which the present invention was applied were prepared, and tire noise was measured using a drum tester.
[0033]
Tires used in Examples 1 to 20 and Comparative Example are as follows.
Each tire size is 195 / 65R14, the belt layer is composed of two belts using steel cords of 1 × 5 × 0.23 structure, and the driving angles of the cords are 24 ° each on the left and right sides with respect to the tire circumferential direction. ± 2 °, the number of cords to be driven is 34/50 mm.
[0034]
In Examples 1 to 20, a belt reinforcing layer was used in which a single filament of steel was plain-woven and rubber-coated, and the belt reinforcing layer was arranged as shown in FIG. The width of each of the belt reinforcing layers was 30 mm.
[0035]
On the other hand, the tire of the comparative example is a tire having no belt reinforcing layer.
The tire noise was measured as follows.
[0036]
Using a drum tester with an outer diameter of 3m with irregularities on the drum surface, controlling the ambient temperature to 30 ± 3 ° C, and placing a test tire of size 195 / 65R14 on a standard rim specified by JAMTA under standard internal pressure and standard load. And the noise level (100 to 400 Hz) at a running speed of 60 km / h was measured.
[0037]
Tables 1 and 2 show the results of the evaluation of the specifications and tire noise of each test tire.
[0038]
Next, each item in Tables 1 and 2 will be described.
Crossing angle: The crossing angle between the diameter yarn and the weft before expansion of the belt reinforcing layer.
Filament diameter: the outer diameter of the filament.
IM: initial modulus per filament.
Filament spacing: The spacing between filaments before expansion of the belt reinforcement layer.
Belt reinforcement layer elongation margin: The percentage of elongation of the belt reinforcement layer when the belt reinforcement layer is pulled and pantograph-deformed until adjacent fibers contact each other.
-Belt reinforcement layer expansion rate: The ratio of elongation of the belt reinforcement layer in the longitudinal direction (tire circumferential direction).
-Belt reinforcement layer width shrinkage: Shrinkage ratio in the width direction of the belt reinforcement layer when the belt reinforcement layer is expanded by the belt reinforcement layer expansion rate (a minus sign indicates contraction).
The angle of the filament after expansion: The angle of the filament with respect to the width direction of the belt reinforcing layer when the belt reinforcing layer is expanded by the belt reinforcing layer expansion rate.
IM of belt reinforcement layer: The initial modulus of the belt reinforcement layer when the belt reinforcement layer is expanded by the belt reinforcement layer expansion rate.
[0039]
[Table 1]

[0040]
[Table 2]

[0041]
As shown in Tables 1 and 2, it can be seen that the tires of Examples 1 to 20 to which the present invention is applied have significantly reduced tire noise as compared with the tires of Comparative Examples.
[0042]
【The invention's effect】
The radial tire according to claim 1 has the above-described configuration, and thus has an excellent effect that tire noise can be significantly reduced.
[0043]
Further, since the radial tire according to claim 2 is configured as described above, it has an excellent effect that tire noise can be significantly reduced.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a first embodiment of the radial tire of the present invention.
FIG. 2 is a plan view showing a cross section of a part of the belt reinforcing layer shown in FIG.
FIG. 3 is a sectional view showing a second embodiment of the radial tire of the present invention.
FIG. 4 is a plan view showing a cross section of a part of the belt reinforcing layer shown in FIG. 3;
FIG. 5 is a perspective view showing another embodiment of the belt reinforcing layer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Radial tire 12 Bead core 14 Carcass 16 Tread part 18 Sidewall part 20 Belt layer 22 Belt reinforcement layer 24 Belt reinforcement layer 24A First fiber layer 24B Second fiber layer

Claims (2)

A pair of beat portions, a toroidal carcass extending over both beat portions, a tread portion located at a crown portion of the carcass, a belt layer disposed inside the tread portion, and at least both ends of the belt layer And a belt reinforcing layer that covers the part,
The radial tire, wherein the belt reinforcing layer has a network structure including a plurality of fibers, and the fibers are inclined with respect to a tire circumferential direction. A pair of beat portions, a toroidal carcass extending over both beat portions, a tread portion located at a crown portion of the carcass, a belt layer disposed inside the tread portion, and at least both ends of the belt layer And a belt reinforcing layer that covers the part,
The belt reinforcing layer has a first fiber layer in which a plurality of fibers inclined in a predetermined direction with respect to the tire circumferential direction are arranged along the tire circumferential direction, and the fibers of the first fiber layer are in the tire circumferential direction. A second fiber layer in which a plurality of fibers inclined in the opposite direction to the second fiber layer are arranged along the tire circumferential direction.

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