JP2001191765A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire that ensures weight, rolling resistance performance, ride comfort performance, and road noise performance while keeping levels equivalent to or above conventional ones, and ensures appreciably improved steering stability performance. SOLUTION: The pneumatic tire comprises a radial carcass with turnup portions, bead filler rubber with a triangular section, and two or more reinforcing cord layers in a side region spreading from a portion to a sidewall portion. One of the reinforcing cord layers is a spiraled cord layer of at least one rubber covered cord about the tire axis. At least one of the rest of the reinforcing cord layers is a layer where a multitude of rubber covered cord are arrayed at a slant to the cord of the spiraled cord layer. The slantingly arrayed cord layer is adjacent to the bead filler rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire, and more particularly to a pneumatic radial tire for use in relatively small vehicles such as passenger cars and similar vans and pickups, and more particularly to tire weight and rolling resistance. The present invention relates to a pneumatic tire that has particularly improved handling stability while maintaining the current excellent level of performance, ride comfort and road noise (hereinafter referred to as R / N) performance.

[0002]

2. Description of the Related Art In recent years, along with the emergence of environmental problems and global warming problems on a global scale and the advancement of automobile performance, pneumatic tires for automobiles, especially tires used in relatively small vehicles mentioned at the beginning, have become increasingly popular. In addition to the need for further improvements in weight reduction, fuel economy performance (low rolling resistance performance), etc., it is necessary to improve a wide variety of performances such as steering stability performance, ride comfort performance, vehicle interior noise performance, especially R / N performance. There is a tendency that demands for simultaneously improving these various performances are increasing.

With respect to this demand, means for individually improving each performance have been established as described below. (1) Means for improving steering stability performance: securing cornering power, improving tire stiffness, and reducing tread rubber hysteresis loss. (2) Means for improving ride comfort and R / N performance: reducing tire rigidity. (3) Means for reducing weight and improving rolling resistance performance: reducing tire rigidity and reducing hysteresis loss of tread rubber.

[0004]

As described above, it is possible to improve individual performance. However, for example, means for improving steering stability and means for improving ride comfort and R / N performance are completely contradictory. For this reason, at present, it is necessary to rely on the application of glue-like means such as adjusting the gauge of the tread rubber. Further, as is apparent from the above, the improvement direction of the steering stability performance and the low rolling resistance performance are opposite because one of the improvement means is to improve the tire rigidity and the other is to reduce the tire rigidity.

For example, in order to improve the steering stability performance, a rubber-coated steel cord layer or a rubber-coated organic fiber cord layer called a bead insert ply is disposed as a reinforcing cord layer in a side surface region from a bead portion to a sidewall portion. Specific means for increasing the tire rigidity are applied. Since these reinforcing cord layers are a large number of cord arrangement layers inclined in the tire circumferential direction, the tire longitudinal direction (load loading direction), lateral direction (tire axis direction) and front-rear direction (direction orthogonal to the tire axis). As a result, the rigidity of the side surface in each direction is increased, which results in a problem that the riding comfort performance, the R / N performance and the rolling resistance performance are reduced. In particular, in order to significantly improve the steering stability, it is necessary to increase the width of the reinforcing cord layer in the radial direction of the tire.
The degree of decrease in N performance and rolling resistance performance increases.

Therefore, according to the present invention, the tire weight, rolling resistance performance, ride comfort performance and R / N performance are based on the current tire to which the bead portion insert ply is applied. It is an object of the present invention to provide a pneumatic tire that has substantially improved the steering stability performance while securing the same level or higher.

[0007]

According to a first aspect of the present invention, there is provided a tread portion having a pair of sidewall portions and a pair of bead portions connected to both sides of the tread portion. A radial carcass that reinforces each of these portions between bead cores embedded in the bead portion, the radial carcass has a folded portion that turns around each bead core from the inside of the tire to the outside, and the bead portion extends from the bead core to the end of the tread portion. A pneumatic tire comprising a bead filler rubber having a triangular cross section extending in a tapered shape toward the side and having two or more reinforcing cord layers in a side surface region from a bead portion to a sidewall portion, wherein one of the reinforcing cord layers is , Consisting of one or more rubber-coated cords, spirally wound cord layers around the tire axis, with at least a residual reinforcing cord layer One layer comprises an arrangement layer of a number of rubber-coated cords inclined with respect to the cord of the spirally wound cord layer, and the inclined arrangement code layer is arranged adjacent to the bead filler rubber. Tires.

[0008] The present invention described in claim 1 relates to claim 2.
As in the invention described in the above, the spirally wound cord layer is arranged along the tire outer side of the radial carcass folded portion,
Alternatively, as in the invention described in claim 3, the spirally wound cord layer is arranged along the inside of the radial carcass folded portion.

According to the first to third aspects of the present invention, as in the fourth aspect of the present invention, the spirally wound cord layer has a tire radial height within a range of 10 to 60% of a tire sectional height. And the radially inner end of the spirally wound cord layer in the tire radial direction is located at one of the periphery and the vicinity of the bead core.
Here, the section height of the tire means JATMA YEAR BOOK (199
In relation to the outer diameter of the tire described in 9), among them, `` Attach the tire to the applicable rim, make it the specified air pressure,
"1/2" of the difference between the tire outer diameter and the rim diameter under no load.
Hereinafter, a straight line parallel to the tire axis passing through the rim diameter position is referred to as a rim diameter line.

According to the invention described in claims 1 to 4, as in the invention described in claim 5, the turning portion of the radial carcass has a tire radial height within a range of 5 to 45% of the tire sectional height. And in relation to this folded portion height, as in the invention according to claim 6, the spirally wound cord layer has:
It has a height in the tire radial direction that exceeds the height of the radial carcass turnover portion.

According to the invention described in claims 1 to 6, as in the invention described in claim 7, the cord of the spirally wound cord layer is selected from nylon cord, polyester cord, rayon cord, Kevlar cord and steel cord. It is a kind of code to choose.

Further, according to the invention described in claims 1 to 7, as in the invention described in claim 8, the spirally wound cord layer has a number of cords in a range of 15 to 60/5 cm. .

[0013] Further, according to the invention described in claims 1 to 8, as in the invention described in claim 9, the inclined arrayed code layer is arranged between a radial carcass main body and a bead filler rubber, In this regard, as in the tenth aspect of the present invention, the inclined arrangement cord layer is a detachment cord layer composed of a number of rubber-coated cord arrangements having both ends separated in the axial direction of the cord.

Further, according to the invention described in claims 1 to 10, as in the invention described in claim 11, the inclined arrangement cord layer has a height in the tire radial direction within a range of 10 to 60% of the tire sectional height. The radially inner end of the inclined arrayed code layer in the tire radial direction is located at one of the vicinity and the periphery of the bead core.

Further, according to the invention described in claims 1 to 11, as in the invention described in claim 12, the cord of the inclined arrangement cord layer is made of nylon cord, polyester cord, rayon cord, Kevlar cord and steel cord. These codes are arranged in such a manner that, as in the invention described in claim 13, each of the codes in the inclined array code layer is 0 to 75 with respect to the tire radial direction.
It has a tilt angle in the range of °.

Further, according to the invention described in claims 1 to 13, as in the invention described in claim 14, the bead filler rubber has a JIS hardness at 30 ° C. of 65 to 83.
Has a value within the range.

Further, as a modification of the invention described in claims 1 to 14, as in the invention described in claim 15, the bead filler rubber is a reinforcing sheet extending toward the end of the tread portion in contact with the tapered tip portion. Rubber is separately provided, and the sheet rubber has a uniform thickness of 2 mm or less. According to the invention described in claim 15, as in the invention described in claim 16, the reinforcing sheet rubber has a tire sectional height. 30-75% of the
In the radial direction of the tire.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view of a pneumatic tire of the present invention, FIG. 2 is a perspective side view of a spirally wound cord layer of the present invention and other members, and FIG. FIG. 4 is an enlarged cross-sectional view of a main part of the tire shown in FIG. 1, and FIG. 5 is an enlarged cross-sectional view of a main part of a tire different from the tire shown in FIG. FIG. 6 is an enlarged sectional view of a main part of a modified example of the tire shown in FIG.

The tire 1 shown in FIG. 1 is a pneumatic radial tire for use in a relatively small vehicle described at the beginning. The tire 1 has a pair of beads 2, a pair of sidewalls 3, And a tread portion 4 connected thereto. Each of these portions 2 to 4 is reinforced by a radial carcass 6 of one or more ply extending between the bead cores 5 embedded in the bead portion 2, in the illustrated example, one ply. Further, the tread portion 4 is reinforced by a belt 7 disposed on the outer periphery of the radial carcass 6. The tread portion 4 has a tread rubber 8 on the outer peripheral side of the belt 7.

The radial carcass 6 has at least one
The ply has a folded portion 6t that folds around each bead core 5 from the inside of the tire 1 to the outside. As the ply cord of the radial carcass 6, an organic fiber cord such as a nylon cord, a polyester cord, a rayon cord, a Kevlar cord, or an inorganic fiber cord or a steel cord such as a carbon fiber cord is applied. In addition, bead part 2
Is provided with a bead filler rubber 9 extending in a tapered shape from the bead core 5 toward the end of the tread portion 4, and the bead filler rubber 9 has a triangular cross section.

The tire 1 is provided with two or more layers, in the illustrated example, two reinforcing cord layers 10 in a pair of side surface areas from the bead portion 2 to the sidewall portion 3. Here, as shown in FIG.
One or more layers, in the illustrated example, one continuous rubber-coated cord 1
It consists of a cord layer 10HW that is helically wound around one axis X of 0HWC. In FIG. 2, for convenience of explanation, adjacent rubber-coated cords 10HWC from the winding start end 10HWs to the winding end 10HWe are shown separated from each other, but at least the adjacent rubber-coated cords 10HWC in the tire 1 are joined to each other, The spirally wound cord layer 10HW has a complete layer shape.

Further, as shown in FIG.
The remaining at least one layer of zero (one layer in the illustrated example) is composed of an array layer 10AR of a number of rubber-coated cords 10ARC inclined with respect to the cord 10HWC of the spirally wound cord layer 10HW. The inclined arrangement code layer 10AR is arranged adjacent to and bonded to the bead filler rubber 9. Like FIG. 2, FIG.
For convenience of explanation, the adjacent rubber-coated cords 10ARC are shown separated from each other, but at least the adjacent rubber-coated cords 10ARC in the tire 1 are joined to each other, and the inclined arrangement cord layer 10AR has a complete layer shape.

First, the ride comfort performance and R / N performance are taken into consideration from the viewpoint of the tire mechanism. (1) The tire 1 that rolls under a load is transferred from the uneven portion of the running road surface to the ground tread portion 4. The impact force is input, (2) the impact force is transmitted to the belt 7 via the tread rubber 8, and the belt 7 vibrates. (3) The vibration of the belt 7 is
And transmitted from the bead portion 4 to the rim (indicated by a two-dot chain line in FIG. 1), and (4) the vibration of the rim causes the vehicle to vibrate. Leads to poor / good ride comfort and R / N performance. Therefore, reducing the rigidity of the sidewall portion 3 in the radial direction of the tire 1 (hereinafter referred to as the radial direction) is effective for improving the riding comfort performance and the R / N performance.

Next, the steering stability performance does not depend on the degree of the overall rigidity of the tire which is largely determined, but rather the rigidity of the side surface region from the bead portion 2 to the sidewall portion 3 and the rigidity of the tread portion 4. Is determined by the degree of rigidity of each of them. Above all, the stiffness of the side surface area plays an important role in the steering stability, and the stiffness is also determined by the lateral stiffness substantially orthogonal to the traveling direction of the tire 1 and the stiffness in the traveling direction, that is, the longitudinal stability. Good or bad. Steering stability can be improved by increasing the lateral rigidity and the longitudinal rigidity.

Lastly, the rolling resistance is determined by the viscoelastic material,
It is mainly caused by the hysteresis loss of the rubber, and thus of the organic fiber cord, which is converted to heat. The outer rubber of the side wall portion 3 has physical properties of low hysteresis loss, and the inorganic fiber cord including the organic fiber cord or the steel cord has much more physical properties of low hysteresis loss. Therefore, the lower the radial rigidity of the side wall portion 3, the lower the rolling resistance.

Here, the spirally wound cord layer 10 described above is used.
By applying the HW and the inclined arrangement code layer 10AR, the following effects (1) to (3) can be obtained. That is, (1) the spirally wound cord layer 1 when filling the tire 1 with the internal pressure.
0HW has low radial stiffness, but high lateral stiffness and front-back stiffness (details will be described later). Therefore,
Originally, the radial arrangement width of the inclined arrangement code layer 10AR having high radial rigidity is kept within a narrower range than before, and instead the spirally wound cord layer 10HW is additionally provided, so that the increase in radial rigidity is suppressed. On the other hand, high levels of lateral rigidity and longitudinal rigidity can be secured.

As a result, each side surface region to which the spirally wound cord layer 10HW and the inclined arrangement code layer 10AR are applied is replaced with the conventional side surface region of the tire on which only the inclined arrangement code layer having a wide radial arrangement width is arranged. In comparison, the degree of bending increases,
As a result, the damping effect of the vibration acceleration is improved, the ability to absorb the vibration brought from the belt 7 is further improved, and the vibration transmission rate to the bead portion can be reduced,
Vibration comfort and R / N performance are greatly improved. Note that R / N is represented by the overall decibel (A) value.

(2) On the other hand, in the contact area of the tire 1 filled with internal pressure, the cord 10HWC of the spirally wound cord layer 10HW
As a result, the rigidity of the cord 10HWC itself is increased, so that the lateral rigidity of each side area along the arrangement direction of the cord 10HWC is increased, and the lateral rigidity of both areas is increased. The cornering power of the tire 1 is improved even if the radial arrangement width of the 10AR is reduced. Thereby, the steering stability performance is improved.

(3) As described above, the radial stiffness of each side surface region to which the spirally wound cord layer 10HW and the inclined arrangement code layer 10AR are applied is the same as that of the above-described conventional tire. The rigidity of the tread portion 4 is lower than that of the conventional tire, so that the side surface region has a greater amount of overhang deformation to the outside of the tire 1 than that of the conventional tire. As a result, the rolling resistance is reduced at least as compared with the conventional tire described above.

As is evident from the above description, simultaneous improvement of steering stability performance, ride comfort performance, R / N performance and rolling resistance performance is achieved. Further, the weight of the tire 1 can be suppressed to a weight equal to or less than that of the conventional tire described above.

Further, providing the spirally wound cord layer 10HW on each side surface region of the tire 1 is extremely anisotropic which cannot be obtained with the high hardness bead filler rubber 9 and the inclined arrangement cord layer 10AR. In other words, the tire 1 utilizes the property of high rigidity in the front-rear direction and low rigidity in the radial direction. By combining the tire 1 with the inclined arrangement code layer 10AR, the ride comfort and performance which have conventionally been sacrificed are improved. Improve R / N performance and rolling resistance performance,
It is possible to exhibit at least the same level of steering stability performance as that of a conventional tire having a radially wide arrangement width.

Hereinafter, the spirally wound cord layer 10HW, the inclined arrangement cord layer 10AR and the bead filler rubber 9 will be described in detail. First, as shown in FIGS. 1 and 4, the spirally wound cord layer 10HW is arranged along the outside of the tire 1 at the folded portion 6t, and at the inside of the tire 1 at the folded portion 6t as shown in FIG. Both the case where it arrange | positions along and it is permissible. In an asymmetric tire, the spirally wound cord layers 10HW may be arranged on the inside and outside of the folded portion 6t on both sides of the tire equatorial plane E.

Next, the spirally wound cord layer 10HW has a sectional height SH (as defined above, the same applies hereinafter) of the tire 1 of 10%.
The radially inner end 10HWie of the spirally wound cord layer 10HW is located near or around the bead core 5 with a radial height h10HW in the range of ６０60%. Under this condition, if the height h10HW is less than 10%, the desired steering stability cannot be obtained. If the height h10HW exceeds 60%, the effect hardly changes. The resulting failure occurs. Here, the radial height refers to a height from the rim diameter line (as defined above) RL, and is the same hereinafter.

On the other hand, the folded portion 6t of the radial carcass 6 has a height h6t in the range of 5 to 45% of the sectional height SH of the tire 1. And the spirally wound cord layer 10
The height h10HW of the HW is greater than the height h6t of the folded portion 6t. If the height h6t is less than 5%, the ply member of the radial carcass 6 cannot maintain tension during tire production. For example, if the height h6t exceeds 45%, the rigidity of the tire 1 becomes excessively high. This impairs compatibility between steering stability performance, ride comfort performance (R / N performance), and rolling resistance performance.

Next, the cord 1 of the spirally wound cord layer 10HW
0HWC is a type of cord selected from nylon cord, polyester cord, rayon cord, Kevlar cord and steel cord. Which code is selected depends on the setting of the required steering stability performance, ride comfort performance, R / N performance, and rolling resistance performance.

Next, the cord 1 of the spirally wound cord layer 10HW
The number of shots of 0HWC is 15 to 60 pieces / 5 cm. Here, the number of hits is a unit length measured in a direction orthogonal to the cord axis, here, the number of cords 10HWC per 5 cm. The number of shots is set in accordance with the type of the code 10HWC in which the performance is entangled.

Next, it is assumed that the inclined arrangement code layer 10AR is disposed between the radial carcass main body 6b and the bead filler rubber 9. In the illustrated example, the inclined arrangement code layer 10AR includes the outside of the radial carcass body 6b and the
Join with the inside. Further, the cord 10ARC constituting the inclined arrangement code layer 10AR has both ends separated in the axial direction. That is, the inclined arrangement code layer 10AR is a separation code layer composed of an arrangement of a number of rubber-coated code cords 10ARC.

Next, the inclined arrangement cord layer 10AR has a radial height h10AR within the range of 10 to 60%, preferably within the range of 10 to 40% of the sectional height SH of the tire 1.
Further, the radially inner end 10AR of the inclined arrangement code layer 10AR.
ie is located near or around the bead core. Under this condition, if the height h10AR is less than 10%, the desired steering stability cannot be obtained. If the height h10AR exceeds 60%, the desired ride comfort, R / N performance and rolling resistance can be obtained. Are not applicable, and all are incompatible.

Next, the code 1 of the inclined arrangement code layer 10AR
0ARC selects one kind of cord from nylon cord, polyester cord, rayon cord, Kevlar cord and steel cord. Which code is selected depends on the setting of the required steering stability performance, ride comfort performance, R / N performance, and rolling resistance performance.

Next, each cord 10ARC of the inclined arrangement code layer 10AR has an inclination angle in the range of 0 to 75 °, preferably in the range of 40 to 70 ° with respect to the radiation direction of the tire 1.

Finally, the bead filler rubber 9 is heated at 30 ° C.
Is in the range of 65 to 83, preferably in the range of 70 to 80. Outside this range, simultaneous improvement of ride comfort, R / N performance and rolling resistance performance is impeded. In addition, the radial height h of the bead filler rubber 9
9 is in the range of 10 to 75% of the tire section height SH, and both heights are acceptable.

Hereinafter, a modified example of the tire 1 will be described. FIG.
As shown in the figure, the bead filler rubber 9 having a relatively low height h9 in the radial direction separately has a reinforcing sheet rubber 11 extending toward the end of the tread portion 4 in contact with the tip including the tapered tip 9p. The sheet rubber 11 has a uniform thickness of 2 mm or less, preferably in the range of 0.3 to 1.0 mm.
The height h11 of the radially outer end 11oe of the reinforcing sheet rubber 11 is in the range of 30 to 75%, preferably 45 to 60% of the sectional height SH of the tire 1. This configuration is adapted to prioritize steering stability performance over ride comfort performance and R / N performance.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A radial ply tire 1 for a passenger car, having a size of 195 / 65R15, has a configuration according to the embodiment shown in FIG. Cord 10HW of spiral wound cord layer 10HW
Nylon cord is applied to C, and the inclined arrangement cord layer 10
A steel cord was applied to each AR 10 cord of the AR.
The number of hits of the cord 10HWC is 45 / 5cm, and the number of hits of the cord 10ARC is 35 / 5cm. Tire 1
Has a sectional height SH of 125 mm.

The tires of Conventional Example 1 having neither the spirally wound code layer 10HW nor the inclined arrangement code layer 10AR, and the tires of Conventional Examples 2 and 3 having only the inclined arrangement code layer 10AR,
A comparative tire provided with the spirally wound code layer 10HW but not provided with the inclined arrangement code layer 10AR was prepared. Table 1 shows the essential structure of the example tire, the tires of Conventional Examples 1 to 3, and the comparative tire. All of the tires of Conventional Examples 1 to 3 and Comparative Example Tire were matched with the Example Tire except for the portions shown in Table 1. In Table 1, the bead filler rubber 9 is abbreviated as BF rubber, and the radial height h10AR of the obliquely arranged cord layer 10AR.
The difference between the height and the radial height of the inner end 10ARie of the same layer 10AR is shown as the inclined arrangement code layer 10AR width (mm).

[0045]

[Table 1]

Each tire shown in Table 1 was used as a test tire.
An indoor test and an actual vehicle test were performed. In the indoor test, first, the tire weight was measured. The measurement results are shown in Conventional Example 1.
Of the tire weight of 100. The smaller the value, the better. Next, the radial stiffness is the longitudinal spring constant,
The lateral stiffness was represented by a lateral spring constant, and the longitudinal rigidity was represented by a longitudinal spring constant, and these constants were measured.
The measurement results were represented by an index with the spring constant of Conventional Example 1 being 100. The higher the value, the higher the rigidity.

Next, the rolling resistance was measured, and the resistance was divided by the applied load to obtain a rolling resistance coefficient. This rolling resistance coefficient was represented by an index with Conventional Example 1 being 100.
The larger the value, the better.

In the actual vehicle test, a skilled test driver runs on a predetermined course on a test course, and the tire of the conventional example 1 is set as a reference point (zero) by feeling of steering stability performance and ride comfort. Additional points within the range of ± 5 points,
The deduction system was used. Of course, the larger the value of the additional point (plus point), the better. Also, the overall value of dB (A) is measured as the R / N performance using the in-vehicle noise when traveling on the R / N generating road surface. A) Value, less than minus dB
(A) was calculated. The larger the value of minus dB (A), the better. Table 1 shows the results.

From the results shown in Table 1, with respect to the steering stability performance, the tires of the example maintain substantially the same tire weight as the tires of Conventional Examples 2 and 3, which are actual comparative tires, and exhibit a rolling resistance performance. Excellent, individually, the ride comfort performance and R / N performance were almost equivalent to the tire of Conventional Example 2, and the steering stability performance was greatly improved. It can be seen that the ride comfort performance and the R / N performance are significantly improved after the performance is made equal. On the other hand, the comparative example tire is compared with the tires of Conventional Examples 2 and 3,
Although the riding comfort performance and the R / N performance are improved, the steering stability performance remains at the same level or less, and in this regard, it can be seen that the effectiveness of combining the spirally wound cord layer 10HW with the inclined arrangement cord layer 10AR.

[0050]

According to the invention described in claims 1 to 16 of the present invention, the weight of a conventional lightweight tire is maintained, and
To provide a pneumatic tire capable of simultaneously improving rolling resistance performance, steering stability performance, ride comfort performance, and R / N performance while maintaining bead durability at a level that is not problematic in the market. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pneumatic tire according to the present invention.

FIG. 2 is a perspective side view of the spirally wound cord layer and other members of the present invention.

FIG. 3 is a perspective side view of the inclined arrangement code layer and other members of the present invention.

FIG. 4 is an enlarged sectional view of a main part of the tire shown in FIG.

FIG. 5 is an enlarged sectional view of a main part of a tire different from the tire shown in FIG.

FIG. 6 is an enlarged sectional view of a main part of a modified example of the tire shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Bead part 3 Side wall part 4 Tread part 5 Bead core 6 Radial carcass 6b Radial carcass body 6t Turnback part 7 Belt 8 Tread rubber 9 Bead filler rubber 9p Bead filler rubber tip 10 Reinforcement cord layer 10HW spirally wound cord layer 10HWC Spiral winding cord 10HWs Spiral winding cord start 10HWe Spiral winding cord end 10AR Inclined cord layer 10ARC Inclined cord 10HWie Radial inner end of spiral coiled cord layer 10ARie Radial inner end of inclined coil cord layer 11 Reinforcing sheet rubber E Tire equatorial plane X Tire axis line RL Rim diameter line SH Tire section height h6t Folding part height h9 Bead filler rubber height h10HW Spiral wound cord layer height h10AR Separation cord layer height h11 Reinforcement sheet rubber height

Claims (16)

[Claims] 1. A radial carcass comprising: a tread portion; a pair of sidewall portions and a pair of bead portions connected to both sides thereof; and a radial carcass for reinforcing these portions between bead cores embedded in the bead portions. Has a folded portion that folds around each bead core from the inside of the tire to the outside, and the bead portion includes a bead filler rubber having a triangular cross section extending from the bead core to the end of the tread portion, and from the bead portion to the sidewall portion. In a pneumatic tire having two or more reinforcing cord layers in the side surface region, one of the reinforcing cord layers is formed of a spirally wound cord layer of one or more rubber-coated cords around the tire axis. At least one remaining layer of the cord layer is formed of a number of rubber-coated cords inclined with respect to the cord of the spirally wound cord layer. Consist sequence layer, the pneumatic tire characterized by comprising the arrangement the inclined arrangement cord layer is adjacent to the bead filler rubber. 2. The tire according to claim 1, wherein the spirally wound cord layer is arranged along a radial carcass folded portion along the tire outside. 3. The tire according to claim 1, wherein the spirally wound cord layer is arranged along the inside of the radial carcass folded portion. 4. The spirally wound cord layer has a height in the tire radial direction within a range of 10 to 60% of a tire cross-sectional height, and a radially inner end of the spirally wound cord layer has a periphery of a bead core and The tire according to any one of claims 1 to 3, which is located in any one of the vicinity. 5. The tire according to claim 1, wherein the turning portion of the radial carcass has a height in a tire radial direction within a range of 5 to 45% of a tire cross-sectional height. 6. The tire according to any one of claims 1 to 5, wherein the spirally wound cord layer has a height in a tire radial direction exceeding a height of a radial carcass folded portion. 7. The tire according to claim 1, wherein the cord of the spirally wound cord layer is a kind of cord selected from nylon cord, polyester cord, rayon cord, Kevlar cord and steel cord. . 8. The spirally wound cord layer has a length of 15 to 60 wires / 5.
The tire according to any one of claims 1 to 7, wherein the number of cords is in a range of cm. 9. The tire according to claim 1, wherein the inclined arrangement cord layer is disposed between a radial carcass main body and a bead filler rubber. 10. The tire according to any one of claims 1 to 9, wherein the inclined arrangement cord layer is a detachment cord layer comprising a large number of rubber-coated cord arrangements having both ends separated in the cord axis direction. 11. The inclined arrangement cord layer has a tire radial height within a range of 10 to 60% of a tire cross-sectional height,
The tire radially inner end of the inclined arrangement cord layer is located at one of the vicinity and the periphery of the bead core.
0. The tire described in any one of 0. 12. The tire according to claim 1, wherein the cord of the inclined arrangement cord layer is a kind of cord selected from nylon cord, polyester cord, rayon cord, Kevlar cord and steel cord. 13. The tire according to claim 1, wherein each cord of the inclined arrangement cord layer has an inclination angle in the range of 0 to 75 ° with respect to the tire radial direction. 14. The tire according to claim 1, wherein the bead filler rubber has a JIS hardness at 30 ° C. within a range of 65 to 83. 15. The bead filler rubber further includes a reinforcing sheet rubber extending toward the end of the tread portion in contact with the tapered tip portion, and the sheet rubber has a uniform thickness of 2 mm or less. A tire according to any one of the preceding claims. 16. The tire according to claim 15, wherein the reinforcing sheet rubber has a height in a tire radial direction within a range of 30 to 75% of a tire sectional height.