JP2010163009A - Tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire increasing the rigidity of its bead part and improving the controllability and stability of a vehicle without impairing a ride comfort. <P>SOLUTION: The pneumatic tire 1 includes: a pair of bead parts 10 including at least a bead core 10a and a bead filler 10b; and a carcass 12 toroidally connecting the pair of bead parts 10 with each other, and further includes a side reinforcement layer 8 provided along the bead filler 10b. The side reinforcement layer 8 is provided on the outside in the tread width direction of the carcass 12 in a cross section along the tread width direction W and along the tire radial direction, and is composed of rubber which is the same material as the bead filler. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tire including a pair of bead portions including at least a bead core and a bead filler and a carcass that connects the pair of bead portions in a toroidal shape.

  Conventionally, in a tire mounted on an automobile, various methods for increasing the rigidity of the tire have been used in order to improve steering stability.

  For example, a method of increasing the rigidity in the tire radial direction by extending a bead filler to the vicinity of a belt layer provided below the tread in a cross section of the tire along the tread width direction is known.

  However, in the tire including such a bead filler, rigidity in the tire radial direction is increased, but on the other hand, a longitudinal spring component is increased and riding comfort is reduced.

  Accordingly, tires having a reinforcing cord layer in the sidewall portion are widely used (for example, Patent Document 1). Such a reinforcing cord layer has a configuration in which the reinforcing cord is wound along the tire circumferential direction. The reinforcing cord layer reduces the strength of the outer side in the tire radial direction by decreasing the density of the reinforcing cord as it goes outward in the tire radial direction. As a result, the tire can improve the steering stability of the vehicle by reducing the rigidity of the bead portion without reducing the riding comfort.

JP 2002-347414 A (2nd page, FIG. 2)

  However, the conventional method described above, that is, the method of improving the steering stability of the vehicle without reducing the ride comfort by using the reinforcing cord layer in the sidewall portion has the following problems. . That is, with the improvement of so-called sports running performance such as high-speed stability performance and turning performance of vehicles, further steering stability performance for tires is required.

  That is, in the tire described above, the tire has low rigidity, and further improvement in handling stability performance is required.

  Therefore, the present invention has been made in view of such a situation, and an object thereof is to provide a tire that can further improve the steering stability of a vehicle without reducing ride comfort.

  In order to solve the above-described problems, the present invention has the following features. First, a first feature of the present invention is that a pair of bead parts (bead part 10) including at least a bead core (bead core 10a) and a bead filler (bead filler 10b), and a carcass that connects the pair of bead parts in a toroidal shape ( And a side reinforcing layer (side reinforcing layer 8) provided along a bead filler, the side reinforcing layer extending along the tread width direction and the tire radial direction. In the cross section, the tire is provided on the outer side in the tread width direction of the carcass and is made of rubber made of the same material as the bead filler.

  According to such a tire, since the side reinforcing layer is provided on the outer side in the tread width direction of the carcass along the bead filler, the front and rear springs can be improved while suppressing an increase in the vertical spring. In other words, the side reinforcing layer can suppress a decrease in tire riding comfort by suppressing an increase in the vertical spring. Further, the side reinforcing layer improves the rigidity of the bead portion by improving the front and rear springs.

  Furthermore, since the side reinforcement layer is made of the same material rubber as the bead filler, it is effective because it is formed in a harder and thinner shape than the reinforcement cord layer in which the reinforcement cord is wound along the tire circumferential direction. The front and rear springs can be improved.

  Therefore, the tire can improve the steering stability of the vehicle without reducing the riding comfort.

  The second feature of the present invention is related to the first feature of the present invention, wherein the side reinforcing layer has a cross section along the tread width direction and the tire radial direction, at least from the outer side in the tire radial direction of the bead filler. The gist is that it is provided between the inner sides in the tire radial direction.

  A third feature of the present invention relates to the first or second feature of the present invention, and is a fiber extending outward in the tire radial direction along the bead filler in a cross section along the tread width direction and the tire radial direction. A reinforcing layer (fiber reinforcing layer 18) is provided, the fiber reinforcing layer is provided on the inner side in the tread width direction than the bead filler, and the height of the fiber reinforcing layer along the tire radial direction (fiber reinforcing layer H18) is the rim base. The gist is that it is formed at a height of 45% or less with respect to the height from the line to the tire maximum width (section height SH).

A fourth feature of the present invention relates to any one of the first to third features of the present invention, wherein the belt layer includes two crossing belt layers (crossing belt layer 24), the tread width direction and the tire diameter. In the cross section along the direction, the carcass is folded outward in the tread width direction by the bead core,
The carcass folded outward in the tread width direction extends outward in the tire radial direction, and the end portion of the carcass in the tire radial direction (carcass end portion 12a) folded outward in the tread width direction is a tire of a cross belt layer. It is located on the inner side in the radial direction and is covered by the crossing belt layer.

  A fifth feature of the present invention relates to the second feature of the present invention, wherein the side reinforcing layer is formed from the end of the bead filler on the inner side in the tire radial direction in the cross section along the tread width direction and the tire radial direction. The gist of the invention is that it is provided between the ends of the layers on the inner side in the tire radial direction.

  According to the characteristics of the present invention, the tire can improve the steering stability of the vehicle by increasing the rigidity of the bead portion without reducing the ride comfort.

1 is a partially exploded perspective view of a pneumatic tire 1 according to an embodiment of the present invention. It is sectional drawing of the tire width direction of the pneumatic tire 1 which concerns on embodiment of this invention. It is sectional drawing of the tire width direction of the pneumatic tire 1 which concerns on embodiment of this invention.

  Next, embodiments according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Embodiment]
In this embodiment, (1) overall configuration of tire, (2) detailed configuration of side reinforcing layer, (3) detailed configuration of fiber reinforcing layer, (4) comparative evaluation, 5) action and effect, (6) other The embodiment will be described.

(1) Overall Configuration of Tire FIG. 1 is a partially exploded perspective view including a cross section in the tread width direction of a pneumatic tire 1 in an embodiment of the present invention. Hereinafter, each part which comprises the pneumatic tire 1 is demonstrated.

  Specifically, (1.1) bead portion, (1.2) carcass, (1.3) bead reinforcing layer, (1.4) side reinforcing layer, (1.5) fiber reinforcing layer, (1. 6) Crossing belt layer, (1.7) Layer layer will be described.

(1.1) Bead part As shown in Drawing 1, pneumatic tire 1 has a pair of bead parts 10 containing at least bead core 10a and bead filler 10b. Specifically, a steel cord or the like is used for the bead core 10a constituting the bead unit 10.

  In the cross section along the tread width direction W and the tire radial direction, the thickness of the bead filler 10b along the tread width direction W becomes thinner toward the inner side in the tire radial direction.

  The height of the bead filler 10b along the tire radial direction is 45% or less with respect to the section height SH that is the height from the rim base line to the tire maximum width.

  The section height SH is a distance from the outer end in the radial direction of the pneumatic tire 1 to the rim base line. The rim baseline is defined as the tire axial line that determines the rim diameter defined by the rim standards of JATMA (Japan Automobile Tire Association), TRA (American Tire and Rim Association) and ETRTO (European Tire and Rim Technical Organization). The

(1.2) Carcass
The pneumatic tire 1 includes a carcass 12 that connects a pair of bead portions 10 to each other in a toroidal shape.

  The carcass 12 is composed of a carcass cord and rubber, and forms a skeleton of the pneumatic tire 1.

  In the cross section along the tread width direction W and the tire radial direction, the carcass 12 is folded back from the tread width direction inner side to the tread width direction outer side by the bead core 10a.

  The carcass 12 folded back outward in the tread width direction extends outward in the tire radial direction. Specifically, the carcass 12 folded back outward in the tread width direction is a bead core 10a and extends outward in the tire radial direction along the bead filler 10b. The folded carcass 12 extends to the outer end of the bead filler 10b in the tire radial direction, and then extends along the carcass 12 (the carcass 12 before being folded) positioned on the inner side in the tread width direction.

  A carcass end portion 12 a that is an end portion of the folded carcass 12 on the outer side in the tire radial direction is located on the inner side in the tire radial direction of the crossing belt layer 24 and is covered with the crossing belt layer 24.

(1.3) Bead reinforcement layer Between the bead core 10a and the carcass 12, a bead reinforcement layer 14 is disposed around the bead core 10a and folded back from the tire radial inner side to the tire radial outer side.

  Specifically, the bead reinforcement layer 14 is configured by impregnating a predetermined organic fiber cord with a rubber component. The predetermined organic fiber cord is preferably an aramid fiber.

  An inner liner 16 that is a highly airtight rubber layer corresponding to a tube is provided on the inner side in the tire radial direction of the carcass 12 and the bead reinforcing layer 14.

(1.4) Side reinforcement layer The pneumatic tire 1 is provided with the side reinforcement layer 8 provided along the bead filler 10b. The side reinforcing layer 8 reinforces the bead filler 10b.

(1.5) Fiber reinforcement layer
The pneumatic tire 1 includes a fiber reinforcement layer 18 that extends outward in the tire radial direction along the bead filler 10b.

(1.6) Cross belt layer
The pneumatic tire 1 includes two intersecting belt layers 24 (a belt layer 20a and a belt layer 20b). The crossing belt layer 24 includes a belt layer 20a coupled to the outer side of the bead reinforcing layer 14 in the tire radial direction and a belt layer 20b disposed on the outer side of the belt layer 20a in the tire radial direction. The belt layer 20a and the belt layer 20b are configured by impregnating a predetermined organic fiber cord with a rubber component. The arrangement directions of the cords of the belt layer 20a and the belt layer 20b are different.

(1.7) Layer Layer The pneumatic tire 1 includes a pair of layer layers 32 that cover both ends of the intersecting belt layer 24 in the tread width direction.

  The layer layer 32 has the 1st layer layer 30a and the 2nd layer layer 30b provided in the tire radial direction outer side of the 1st layer layer 30a. The layer layer 32 is configured by impregnating a rubber component into a hybrid belt reinforcing cord including at least a highly elastic organic fiber cord and a low elasticity organic fiber cord.

(2) Detailed configuration of side reinforcing layer The detailed configuration of the side reinforcing layer 8 provided along the bead filler 10b will be described with reference to FIGS. FIG. 2 is a cross-sectional view of the pneumatic tire 1 in the tread width direction. FIG. 3 is an enlarged cross-sectional view of a part of the pneumatic tire 1 in the tread width direction.

  The side reinforcing layer 8 is provided on the outer side in the tread width direction of the carcass 12 in the cross section along the tread width direction W and the tire radial direction, and is made of rubber made of the same material as the bead filler 10b.

  The rubber made of the same material as the bead filler 10b constituting the side reinforcing layer 8 does not mean that the material of the bead filler 10b is all the same. For example, the main component of the constituting rubber is the same. It means that there is. However, the rubber constituting the side reinforcing layer 8 can reduce the manufacturing cost when all of the material of the bead filler 10b is the same.

  The side reinforcing layer 8 is provided between at least the outer side in the tire radial direction of the bead filler 10b and the inner side in the tire radial direction of the belt layer in the cross section along the tread width direction W and the tire radial direction. Specifically, the side reinforcing layer 8 has a cross section along the tread width direction and the tire radial direction, from the end portion on the inner side in the tire radial direction of the bead filler 10b to the end portion on the inner side in the tire radial direction of the crossing belt layer 24. Between.

  The side reinforcing layer H8, which is the height of the side reinforcing layer 8 along the tire radial direction, is formed higher than the height of the bead filler 10b along the tire radial direction.

(3) Detailed Configuration of Fiber Reinforcement Layer The fiber reinforcement layer 18 is provided on the outer side in the tread width direction than the carcass 12 and on the inner side in the tread width direction than the bead filler 10b. Specifically, the fiber reinforcement layer 18 is configured by impregnating a predetermined organic fiber cord with a rubber component. The predetermined organic fiber cord is preferably an aramid fiber.

  The fiber reinforcement layer H18, which is the height of the fiber reinforcement layer 18 along the tire radial direction, is formed at a height of 45% or less with respect to the section height SH, which is the height from the rim base line to the tire maximum width. The

(4) Comparative Evaluation Next, in order to further clarify the effect of the present invention, comparative evaluation performed using pneumatic tires according to the following comparative examples and examples will be described. Specifically, (4.1) Evaluation method and (4.2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(4.1) Evaluation method Using seven types of pneumatic tires, the steering stability performance and ride comfort were evaluated. Data on pneumatic tires were measured under the following conditions.

・ Tire size: 225 / 40R19 89Y
・ Rim wheel size: 19 × 8J
・ Internal pressure: 240 kPa
・ Vehicle type: Automobiles (Sports type with FR displacement 2000cc turbo)
・ Driving stability performance: Feeling evaluation by driver on high speed test course (circuit field) and general road ・ Riding comfort: Feeling evaluation by driver on high speed test course (circuit field) and general road Steering stability performance and riding comfort The sex evaluation results were evaluated on a 10-point scale and evaluated based on the following criteria (8; very good 7; good 6; neither can be said 5; not good).

  In addition, about the evaluation result of the longitudinal spring, the lateral spring, and the front and rear spring that affect the riding comfort, the measurement result in the pneumatic tire of Comparative Example 1 was set to 100 and displayed as an index. The numerical values indicating the evaluation results of the longitudinal spring, the lateral spring, and the longitudinal spring indicate that the larger the value, the better.

    In the pneumatic tires of Comparative Examples 1 to 4 and Examples 1 to 3, the position of the carcass end, the height of the bead filler, the presence / absence of a side reinforcing layer, and the presence / absence of a fiber reinforcing layer are different.

  The position of the carcass end indicates the percentage of the carcass end positioned from the rim base line side with respect to the section height SH of the pneumatic tire 1. When the carcass end is located on the inner side of the crossing belt layer in the tire radial direction and is covered with the crossing belt layer, the position of the carcass end is “just below the crossing belt layer”.

  The height of the bead filler indicates the height of the bead filler along the tire radial direction, and indicates the ratio to the section height SH.

  The pneumatic tire of Example 1 is greatly different from the pneumatic tires of Comparative Examples 1 to 4 in that a side reinforcing layer is provided.

  The pneumatic tire of Example 2 is different from the pneumatic tire of Example 1 in that the position of the end of the carcass is “just below the crossing belt layer”.

  The pneumatic tire of Example 3 is different from the pneumatic tire of Example 2 in that it includes a fiber reinforcing layer. In addition, the pneumatic tire 1 which concerns on this embodiment was used for the pneumatic tire of Example 3.

(4.2) Evaluation Results The evaluation results for each pneumatic tire will be described with reference to Table 1.

  In the pneumatic tires according to Comparative Examples 1 and 2, although the ride comfort meets the standard, the steering stability performance of the vehicle did not satisfy the standard.

  The pneumatic tire according to Comparative Example 3 was slightly improved in steering stability as compared with the pneumatic tire of Comparative Example 1, but the ride comfort was reduced.

  Compared with the pneumatic tires according to Comparative Examples 1 to 3, the pneumatic tires according to Examples 1 to 3 were confirmed to improve the steering stability performance of the vehicle without lowering the riding comfort.

  In particular, the pneumatic tire of Example 3 showed excellent values for ride comfort and handling stability.

  In addition, it was confirmed that the pneumatic tires according to Examples 1 to 3 improved the steering stability performance of the vehicle without reducing the riding comfort as compared with the pneumatic tires according to Comparative Examples 1 to 3.

(5) Action / Effect As described above, according to the pneumatic tire 1 according to the present embodiment, the side reinforcing layer 8 is provided on the outer side in the tread width direction of the carcass along the bead filler 10b. The front and rear springs can be improved while suppressing the springs from becoming higher. That is, the side reinforcing layer 8 can suppress the ride comfort of the pneumatic tire 1 from being reduced by suppressing the vertical spring from becoming high. Moreover, the side reinforcement layer 8 can raise the rigidity of the bead part 10 by improving a front-rear spring.

  Furthermore, since the side reinforcing layer 8 is made of the same material rubber as the bead filler 10b, it is formed in a hard and thin shape as compared with the reinforcing cord layer in which the reinforcing cord is wound along the tire circumferential direction. The front and rear springs can be improved effectively.

  Therefore, the pneumatic tire 1 can improve the steering stability of the vehicle without reducing the riding comfort.

  In the present embodiment, the side reinforcing layer 8 is provided between at least the outer side of the bead filler 10b in the tire radial direction and the inner side of the belt layer in the tire radial direction in the cross section along the tread width direction and the tire radial direction. In the tire 1, the rigidity of the portion where the load is most applied when the vehicle turns can be improved. Therefore, the pneumatic tire 1 can further improve the steering stability of the vehicle.

In this embodiment, since the fiber reinforcement layer 18 is provided along the bead filler 10b on the inner side in the tread width direction than the bead filler 10b, the pneumatic tire 1 has the side reinforcement layer 8 on the outer side in the tire radial direction of the bead filler 10b. The inner side in the tire radial direction is reinforced by the fiber reinforcing layer 18 to improve the rigidity of the pneumatic tire 1 and further improve the steering stability of the vehicle.

  In addition, since the fiber reinforcement layer 18 is configured by impregnating a predetermined organic fiber cord with a rubber component, the improvement in extreme rigidity is suppressed as compared with a reinforcement layer constituted by a reinforcement layer made of steel cord. Therefore, it is possible to suppress the vertical spring from becoming extremely high.

  The fiber reinforcement layer H18, which is the height of the fiber reinforcement layer 18 along the tire radial direction, is formed at a height of 45% or less with respect to the section height SH, which is the height from the rim base line to the tire maximum width. Therefore, the front and rear springs can be improved while suppressing an increase in the vertical spring.

  In other words, the fiber reinforcement layer 18 formed at a height of 45% or less with respect to the height from the rim base line to the maximum tire width improves the front and rear springs while suppressing the vertical springs from becoming higher. Thus, it is possible to improve the rigidity of the bead portion 10 and further improve the steering stability of the vehicle while suppressing the decrease in the riding comfort of the pneumatic tire 1.

  In the present embodiment, the carcass end portion 12a is located on the inner side in the tire radial direction of the crossing belt layer 24 and is covered with the crossing belt layer 24. Therefore, the carcass 12 folded back by the bead core 10a is in the tire radial direction of the bead filler 10b. It extends from the outer end to the inner side in the tire radial direction of the crossing belt layer 24. Therefore, the pneumatic tire 1 can reinforce the rigidity of the pneumatic tire 1 by reinforcing the outer side in the tire radial direction of the bead filler 10b with the carcass 12 folded back by the bead core 10a.

  The pneumatic tire 1 further including the carcass 12 extended to the inner side in the tire radial direction of the crossing belt layer 24 has a higher vertical spring than the case where the bead filler 10b is extended to the outer side in the tire radial direction. Therefore, the rigidity of the bead portion 10 can be improved and the steering stability of the vehicle can be further improved while suppressing the ride comfort of the pneumatic tire 1 from being lowered.

  In the present embodiment, the side reinforcing layer 8 is between the end portion on the inner side in the tire radial direction of the belt layer and the end portion on the inner side in the tire radial direction of the bead filler 10b in the cross section along the tread width direction and the tire radial direction. Therefore, in the pneumatic tire 1, the rigidity on the outer side in the tire width direction from the bead filler 10b can be further improved. Therefore, the pneumatic tire 1 can further improve the front and rear springs while suppressing an increase in the vertical spring, and thus can further improve the steering stability of the vehicle.

(6) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows.

  In the embodiment described above, the side reinforcing layer 8 has an end portion on the inner side in the tire radial direction of the cross belt layer 24 from an end portion on the inner side in the tire radial direction of the bead filler 10b in a cross section along the tread width direction and the tire radial direction. However, the present invention is not limited to this, and it may be provided at least between the outer side of the bead filler 10b in the tire radial direction and the inner side of the belt layer in the tire radial direction.

  In the embodiment described above, the pneumatic tire 1 includes the fiber reinforcement layer 18, but the fiber reinforcement layer 18 does not necessarily need to be provided. Specifically, the pneumatic tire 1 should just be provided with the side reinforcement layer 8 provided along the bead filler 10b.

  In the embodiment described above, the pneumatic tire 1 includes the two crossing belt layers 24, and the carcass end portion 12a that is the end portion on the outer side in the tire radial direction of the carcass 12 folded back outward in the tread width direction is the crossing belt. The carcass end portion 12a is located on the inner side in the tire radial direction of the layer 24, but the carcass end portion 12a is about 55% of the section height SH that is the height from the rim baseline to the tire maximum width. What is necessary is just to be formed in height.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

SH: Section height, W: Tread width direction, 1 ... Tire,
8 ... side reinforcing layer, 10 ... bead part, 10a ... bead core,
10b ... bead filler, 12 ... carcass, 12a ... carcass end,
14 ... Bead reinforcement layer, 16 ... Inner liner, 18 ... Fiber reinforcement layer,
20a ... belt layer, 20b ... belt layer, 24 ... crossing belt layer,
30a ... 1st layer layer, 30b ... 2nd layer layer, 32 ... Layer layer

Claims (5)

A tire comprising a pair of bead parts including at least a bead core and a bead filler, and a carcass that connects the pair of bead parts in a toroidal shape,
A side reinforcing layer provided along the bead filler;
In the cross section along the tread width direction and the tire radial direction, the side reinforcing layer,
A tire provided on the outer side in the tread width direction of the carcass and made of rubber made of the same material as the bead filler.   2. The tire according to claim 1, wherein the side reinforcing layer is provided at least between the outer side in the tire radial direction of the bead filler and the inner side in the tire radial direction of the belt layer in a cross section along the tread width direction and the tire radial direction. In the cross section along the tread width direction and the tire radial direction,
Along with the bead filler, a fiber reinforcement layer extending outward in the tire radial direction,
The fiber reinforcement layer is provided on the inner side in the tread width direction than the bead filler,
The height of the fiber reinforcement layer along the tire radial direction is 45% or less with respect to the height from the rim base line to the maximum tire width. Item 3. The tire according to Item 2. The belt layer includes two intersecting belt layers,
In the cross section along the tread width direction and the tire radial direction, the carcass is folded back outward in the tread width direction by the bead core,
The carcass folded outward in the tread width direction extends outward in the tire radial direction,
4. The end of the carcass in the tire radial direction, which is folded back in the tread width direction, is located on the inner side in the tire radial direction of the crossing belt layer, and is covered with the crossing belt layer. Tire described in.   The side reinforcing layer is provided between a tire radial inner end of the bead filler and a tire radial inner end of the belt filler in a cross section along the tread width direction and the tire radial direction. Tire described in.

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