JP6750433B2 - Pneumatic tire - Google Patents

Description

The present invention relates to a pneumatic tire.

With heavy-duty bias tires, so-called multi-bead type bias tires in which the bead portion is reinforced with a plurality of bead cores are used to withstand the increase in the load capacity, the increase in vehicle size, and the increase in torque. There is. In particular, in recent years, low-flat multi-bead type bias tires are desired. Such a multi-bead type heavy load bias tire is mounted on a wheel loader (excavator loader or tire dozer) used at, for example, a construction site, a mining site such as a mine, or a quarry. The wheel loader is a vehicle for loading earth and sand and crushed stone on an excavator and transporting it at a low speed. Since the vehicle starts and stops repeatedly under a high load condition, the wheel loader receives a large number of rotation torques at that time very often. Therefore, peeling occurs between the bead core and the carcass layer, a peeling failure in which this peeling expands in the tire radial direction and the tire circumferential direction and progresses, and a bead burst in which the carcass cord breaks around the bead core occurs. There is a problem in terms of durability. In particular, a tire having a low flatness is likely to cause bead bursts.

The carcass layer peeling failure and the bead burst are likely to occur in the innermost bead core (closest to the tire equator line) in the tire width direction and the carcass layer closest to the bead core in the multi-bead type bias tire.

Conventionally, in order to suppress the peeling of the carcass layer and the bead burst, measures such as increasing the number of carcass layers wound around one bead core, increasing the number of bead cores, or increasing the strength of the carcass layer have been taken.

For example, a pneumatic tire having the following configuration is known (Patent Document 1). That is, in a multi-bead type heavy load bias tire, at the bead heel portion of the outermost carcass layer or the bead reinforcing cord layer of the bead heel portion, at least the bead heel auxiliary having a tapered cross-section with a tapered tip from the lower end to the upper end of the outermost bead core. A rubber layer is placed. The hardness of the bead heel auxiliary rubber layer is 70 to 80 (JIS hardness), and the inclination angle of the width center line of at least the outermost bead core of the plurality of bead cores with respect to the tire equatorial plane is 20 to 35 degrees.

JP, 2006-111074, A

According to the multi-bead type heavy load bias tire having the above structure, it is possible to prevent the peeling of the carcass layer around the bead core. However, in the above-mentioned heavy load bias tire, a bead heel auxiliary rubber layer is newly provided, and the inclination angle of the width center line of the outermost bead core with respect to the tire equatorial plane is 20 to 35 degrees, so there are many restrictions on the configuration.

Therefore, an object of the present invention is to provide a pneumatic tire having a structure different from the conventional one, which can prevent the carcass layer around the bead core from peeling off and further suppress bead burst.

One form of the present invention is a pneumatic tire.
The pneumatic tire is
A plurality of bead cores provided in a row in the tire width direction on each of the bead portions on both sides of the pneumatic tire,
A plurality of carcass layers wrapped around each of the bead cores and folded back,
In the tread portion of the pneumatic tire, with respect to the carcass layer, a plurality of belts provided outside the tire radial direction of the pneumatic tire,
The tread portion includes a tread rubber provided outside the belt in the tire radial direction.
Each of the bead cores is a laminated bead core having a configuration in which a bead wire row in which a plurality of bead wires are arranged in a direction along a bead base surface of the bead portion makes one round on a tire circumference and a surrounding layer is stacked in a plurality of stages in a tire radial direction. Is.
In a tire cross section obtained by cutting the pneumatic tire in a plane including the tire rotation axis of the pneumatic tire, with respect to the innermost bead core located at the innermost side in the tire width direction among the bead cores, the bead wire row of the bead portion One of the inner bead wire rows inside the outermost bead wire row located on the outermost side in the tire radial direction in the tire radial direction has more bead wires arranged than the outermost bead wire row, and among the plurality of bead wire rows. Is the maximum bead wire row with the maximum number of bead wires arranged.
The width of the innermost bead core, of the carcass layer located closest to the innermost bead core of the carcass layer, of the portion approaching the innermost bead core in order to wind the innermost bead core from the inner side in the tire width direction. The inclination angle with respect to the center line is 10 degrees or more.

It is preferable that the maximum bead wire row is located at a step of 0.3 times or more the total number of steps of the bead wire row, and a step distant from the outermost bead wire row.

It is preferable that the number of arranged bead wires in the maximum bead wire row is 1.2 times or more the number of arranged bead wires in the outermost bead wire row.

Inner side in the tire width direction with respect to the carcass layer wound around the innermost bead core, an organic fiber reinforced layer in which organic fibers are coated with rubber, the tire radial direction with respect to the outermost bead wire row of the innermost bead core. Is preferably provided in a region outside the.

According to the pneumatic tire described above, peeling of the carcass layer around the bead core can be prevented, and bead burst can be suppressed.

It is a tire sectional view showing an example of a section of a pneumatic tire of this embodiment. It is a figure explaining an example of structure around a bead part of a tire of this embodiment. It is a figure explaining an example of composition of a laminated bead core used for a bead core of a tire of this embodiment. It is a figure explaining in detail an example of composition of an innermost bead core in a tire of this embodiment. (A) is a figure explaining the behavior of the carcass cord of the carcass layer used for the tire of this embodiment at the time of braking/driving (starting or stopping), and (b) is a diagram of the carcass cord used for the conventional tire. FIG. 6 is a diagram for explaining behavior during braking/driving (starting or stopping).

Hereinafter, the pneumatic tire of this embodiment will be described. FIG. 1 is a diagram showing an example of a cross section of a pneumatic tire (hereinafter referred to as a tire) 1 of the present embodiment. The tire 1 is a multi-bead type heavy load bias tire, and is for one type (dump truck, scraper) tire and two types (grader) described in Chapter D of JATMA (Japan Automobile Tire Manufacturers Association Standard) YEAR BOOK 2014. Tires, tires for three types (excavator loaders, etc.), tires for four types (tire rollers), tires for mobile cranes (truck cranes, wheel cranes), or vehicles listed in SECTION 4 or SECTION 6 of TRA 2013 YEAR BOOK It can be applied to tires for use.

In this specification, each direction and side are defined as follows.
The tire width direction is a direction parallel to the rotation axis of the pneumatic tire. The outer side in the tire width direction is the side away from the tire equatorial line CL representing the tire equatorial plane with respect to the position to be compared in the tire width direction. The inner side in the tire width direction is the side closer to the tire equator line CL in the tire width direction with respect to the position to be compared. The tire circumferential direction is the direction in which the pneumatic tire rotates about the rotation axis of the pneumatic tire. The tire radial direction is a direction orthogonal to the rotation axis of the pneumatic tire. The outer side in the tire radial direction refers to the side away from the rotation axis along the tire radial direction with respect to the position to be compared. Further, the inner side in the tire radial direction refers to the side closer to the rotation axis along the tire radial direction with respect to the position to be compared.

(Tire structure)
The tire 1 is a bias tire, and has a carcass 3, a belt 4, and a plurality of pairs of bead cores 5 as a skeleton material, and a tread rubber 6, a side rubber 7, an inner liner 9, etc. around these skeleton materials. Of each rubber layer. The belt 4 is also called a breaker in a bias tire. In FIG. 1, since the carcass 3 has a plurality of carcass layers, it is shown as a region in which the plurality of carcass layers are arranged in a laminated structure.
The belt 4 is, in the tread portion where the tread rubber 6 of the tire 1 is provided, outside the plurality of carcass layers forming the carcass 3 in the tire radial direction of the tire 1 and in the tire radial direction with respect to the tread rubber 6. A plurality of them are provided inside. The belt 4 has an intersecting layer in which two layers of belt material are laminated. In the present embodiment, the belt 4 is a two-layer cross belt, but may be three or more cross belts.
The tread rubber 6 is provided on the tread portion outside the belt 4 in the tire radial direction.

The plurality of bead cores 5 are provided in the same number in a row in the tire width direction on each of the bead portions on both sides. FIG. 2 is a diagram illustrating an example of the structure around the bead portion of the tire according to the present embodiment. In this embodiment, three bead cores 5a, 5b, 5c are provided. In FIGS. 1, 2, 4, and 5, the outline shape of the bead cores 5a, 5b, and 5c is represented by a hexagonal shape or a quadrangular shape, but there is no such shape, and the bead wire located outside is a hexagonal shape. It means that they are arranged in a shape or a rectangular shape.
The carcass 3 includes a plurality of carcass layers, and the plurality of carcass layers are wound around each of the bead cores 5a, 5b, 5c so as to be folded back from the tire width direction inner side to the outer side. Thereby, a plurality of pairs of bead cores 5 around which the same carcass layer is wound are formed. In FIG. 2, regions of a plurality of carcass layers wound around each bead core 5 are represented by 3a, 3b, 3c. Region 3a includes a bundle of carcass layers that wraps around bead core 5a, region 3b includes a bundle of carcass layers that wraps around bead core 5b, and region 3c includes a bundle of carcass layers that wraps around bead core 5c. .. Each of the regions 3a, 3b, 3c includes a plurality of carcass layers, for example, 14 carcass layers. The carcass cord in each carcass layer extends obliquely with respect to the tire radial direction or the tire width direction. Among the carcass cords, the carcass cords of adjacent carcass layers are laminated so that the carcass cords are laminated so as to be inclined on different sides with respect to the tire radial direction or the tire width direction, and thus are intersecting layers. That is, the tire 1 has a bias tire structure.
Bead fillers 8a, 8b, 8c are arranged on the outer sides of the bead cores 5a, 5b, 5c in the tire radial direction, and the bead fillers 8a, 8b, 8c are wrapped by the main body portion and the folded portion of the carcass 3. The bead 8 is formed by the bead cores 5a, 5b, 5c and the bead fillers 8a, 8b, 8c.
A belt 4 including a plurality of belts is provided on the tread rubber 6 on the outer side of the carcass 3 in the tire radial direction.

FIG. 3 is a diagram illustrating an example of the configuration of the laminated bead core 50 used for the bead cores 5a, 5b, 5c of the present embodiment. The laminated bead core 50 includes a plurality of bead wire rows 52a to 52g in which a plurality of bead wires 51 are arranged in a direction along the bead base surface 10 (see FIG. 2), each of which has a plurality of circumferential layers in the tire radial direction. A laminated bead core having a stacked structure. The laminated bead core having such a configuration is different from the one-winding bead core in which one bead wire is densely arranged and wound around the tire circumference to have a predetermined bead core cross-sectional shape (for example, hexagonal shape). In a single-winding bead core, the bead wires are densely arranged and wound, so that the laminated bead core has a lower filling rate of the bead wire than the single-winding bead core, and as a result, is deformed by external force as compared with the single-winding bead core. easy. Since the carcass 3 wound around the bead cores 5a, 5b, 5c has a bias structure, it largely deforms and displaces when the tire 1 is braking/driving. Therefore, the bead cores 5a, 5b, 5c are formed of laminated bead cores 50 that allow deformation so that the bead cores 5a, 5b, 5c can also be deformed in response to the deformation and displacement of the carcass 3. The laminated bead core 50 shown in FIG. 3 has seven laminated layers, but is not limited to seven layers. Further, the number of bead wires arranged in each bead wire row is not limited. Although the maximum number of bead wires arranged in the bead wire row 52d in the middle row (fourth row from the top row) in FIG. 3 is larger than that in other bead wire rows, the bead wire in the middle row. The row is not limited to being the largest bead wire row.

The belt 4 includes two layers of cross belts 4a and 4b.
The cross belts 4a and 4b are provided so as to be laminated in the tire radial direction. The cords (organic fiber cords or steel cords) forming the cross belts 4a and 4b are inclined to one side in the tire width direction with respect to the tire circumferential direction. The crossing belts adjacent to each other in the tire radial direction have different cord inclination directions, and specifically, the cords are inclined from the tire circumferential direction to different sides in the tire width direction. Therefore, the cross belts 4a and 4b exert a hoop effect on the tire that is going to be expanded by the internal pressure filling. The inclination angle of the steel cords of the cross belts 4a and 4b with respect to the tire circumferential direction is set in the range of 20° to 40°, for example.
A protective belt may be provided outside the cross belts 4a and 4b in the tire radial direction.

The tire 1 has the tire structure described above, but is not limited thereto, and the carcass layer has a bias structure and the bead structure in which a plurality of laminated bead cores are provided in a row in the tire width direction is provided. The tire structure is not particularly limited as long as it has a structure.

(Detailed description around the bead)
FIG. 4 is a diagram illustrating in detail an example of the configuration of the innermost bead core in the tire 1 of the present embodiment. The innermost bead core is a bead core 5a located on the innermost side in the tire width direction. Hereinafter, the innermost bead core will be described with reference numeral 5a. As shown in FIG. 4, in a tire cross section obtained by cutting the tire 1 along a plane including the tire rotation axis of the tire 1, the innermost bead core 5a, which is a laminated bead core, is located on the outermost side in the tire radial direction among the bead wire rows of a plurality of stages. One of the inner bead wire rows on the inner side in the tire radial direction of the outermost bead wire row 14 located has a larger number of bead wires arranged than the outermost bead wire row 14 and has the largest number of bead wires arranged among a plurality of bead wire rows. The maximum bead wire row 16.
Therefore, the maximum bead wire row 16 is provided so as to be located inside the outermost bead wire row 14 in the tire radial direction.
The outline shape of the bead core 5a shown in FIG. 4 is a hexagonal shape, but the shape is not limited to this. As long as the maximum bead wire row 16 is one of the inner bead wire rows on the inner side in the tire radial direction from the outermost bead wire row 14, the contour shape is not limited and may be a circular shape, an elliptical shape, a triangular shape, a pentagonal shape, or the like. Good.

Further, on the innermost bead core 5a, the innermost portion of the carcass layer 17 located closest to the innermost bead core 5a of the carcass 3 that is close to the innermost bead core 5a for being wound on the innermost bead core 5a from the inner side in the tire width direction. The inclination angle θ (see FIG. 4) of the bead core 5a with respect to the width center line X is 10 degrees or more. The inclination angle θ is more preferably 15 degrees or more. The inclination angle θ is preferably 30 degrees or less. Here, the width center line X of the innermost bead core 5a refers to the position of the bead wire in the middle of the bead wire in the middle of the bead wire array in the array of the bead wire array of each stage (when the number of bead wires is odd), the position of the bead wire in the middle, When there is no bead wire in the middle of a row in a row (when the number of arranged bead wires is an even number), it is a line that connects the intermediate positions of the positions of the two bead wires closest to the middle for each step, and the line is a curve or In the case of a bending line, it is an approximate straight line obtained by approximating a curve or a bending line with a straight line so as to minimize the error.

As described above, in the present embodiment, the inclination angle θ is set to 10 degrees or more, and the maximum bead wire row 16 is provided on the inner side of the outermost bead wire row 14 in the tire radial direction, whereby the carcass layer 17 is provided around the innermost bead core 5a. Can be prevented, and bead burst can be suppressed.

FIG. 5A is a diagram for explaining the behavior of the carcass cord 19 of the carcass layer used in the tire 1 of the present embodiment during braking/driving (starting or stopping), and FIG. It is a figure explaining the behavior of the carcass cord used for a tire at the time of braking/driving (starting or stopping).
Due to the bias structure, the carcass cord 19 extends in a direction inclined with respect to the tire radial direction, as shown in FIG. Therefore, when the tire 1 is braking/driving (starting or stopping), the carcass cord 19 is deformed so as to move in the tire circumferential direction around the innermost position Y of the innermost bead core 5a in the tire radial direction. .. Therefore, the portion of the carcass cord 19 before being wound close to the innermost bead core 5a is easily displaced so as to rub against the innermost bead core 5a. Due to this displacement, the carcass layer 17 including the carcass cord 19 is easily peeled off. However, in the present embodiment, since the carcass layer 17 including the carcass cord 19 is close to the position Z1 of the maximum bead wire row 16 which is relatively close to the position Y, the displacement amount of the carcass layer 17 with respect to the innermost bead core 5a in this portion is small. Get smaller.

On the other hand, as shown in FIG. 5B, in the bead core of the conventional tire, the carcass layer including the carcass cord is close to the bead core at the position Z2 farther from the position Y than the position Z1. The displacement amount of the carcass layer becomes larger than that in the case shown in FIG.

As described above, in the present embodiment, the maximum bead wire row 16 is provided on the inner side in the tire radial direction with respect to the outermost bead wire row 14, so that the relative displacement amount of the carcass layer 17 with respect to the innermost bead core 5a of the carcass cord 19 is reduced. Since it is possible to reduce the shear strain, peeling of the carcass layer 17 around the innermost bead core 5a can be prevented, and bead burst can be suppressed. By setting the inclination angle θ to 10 degrees or more, when the carcass layer 17 is displaced in the tire circumferential direction, it is suppressed that the carcass layer 17 is strongly pressed against the innermost bead core 5a and rubbed at the position Z1 close to the innermost bead core 5a. Therefore, the effect of preventing peeling of the carcass layer 17 and the effect of suppressing bead burst are further improved.

In the innermost bead core 5a of the present embodiment, the maximum bead wire row 16 is provided on the inner side in the tire radial direction from the outermost bead wire row 14 is that the carcass layer located closest to the innermost bead core 5a rubs against the innermost bead core 5a. This is because peeling easily occurs between the carcass layer and the innermost bead core 5a, which easily leads to the occurrence of bead bursts. Therefore, the inclination angle θ is also an inclination with respect to the width center line X of the carcass layer located closest to the innermost bead core 5a.

In the tire 1 of the present embodiment, it is preferable that the maximum bead wire row 16 is located at a step number 0.3 times or more the total step number of the bead wire row and at a step away from the outermost bead wire row 14. For example, when the total number of bead wire rows is 16, it is preferable that the maximum bead wire row 16 is provided at a position separated by 5 or more steps from the outermost bead wire row 14. By doing so, the effect of preventing peeling of the carcass layer 17 is further improved. The maximum bead wire row 16 is more preferably 0.4 times or more the total number of steps of the bead wire row, further 0.5 or more steps of the total number of steps, and more preferably located at a step distant from the outermost bead wire row 14.

Further, in the tire 1 of the present embodiment, the number of bead wires arranged in the maximum bead wire row 16 is preferably 1.2 times or more the number of bead wires arranged in the outermost bead wire row 14 in the tire cross section. More preferably, it is 1.4 times or more. The upper limit of the number of bead wires arranged in the maximum bead wire row 16 is not limited as long as it is equal to or less than the upper limit of the bead width which is restricted by the rim to be mounted. For example, the number of bead wires arranged in the outermost bead wire row 14 is 1.8. It is preferably not more than double. By doing so, the effect of preventing peeling of the carcass layer 17 is further improved.

Furthermore, it is preferable that the tire 1 of the present embodiment is provided with nylon chafers 20 and 22 (see FIG. 2) which are organic fiber reinforcing layers in which organic fibers are covered with rubber. In this case, the nylon chafers 20 and 22 are located inside the carcass layer 17 wound around the innermost bead core 5a in the tire width direction and outside the outermost bead wire row 14 of the innermost bead core 5a in the tire radial direction. It is provided in the area. When the tire 1 is assembled to the rim, the nylon chafers 20 and 22 preferably extend higher than the height of the rim flange and extend outward in the tire radial direction. Thereby, the deformation of the carcass layer 17 around the innermost bead core 5a can be suppressed, so that the carcass layer 17 around the innermost bead core 5a can be prevented from peeling and the bead burst can be suppressed. In this embodiment, two nylon chafers 20 and 22 are provided, but the number of nylon chafers is not limited as long as the bead width is not larger than the bead base width. For example, the number of nylon chafers is preferably 4 or less.

In addition, regarding the bead cores 5b and 5c of this embodiment, a maximum bead wire row in which the number of bead wires arranged is larger than other bead wire rows may be provided, but may not be provided. As in the past, the number of bead wires arranged in the bead wire row may be the same in all stages. In the bead cores 5b and 5c, peeling of the carcass layer and bead burst hardly occur.

(Experimental example)
In order to investigate the effect of the tire of this embodiment, various tires were produced and the bead durability of the tire was evaluated. The tire size of the manufactured tire is 29.5-25 22PR. The produced tire was mounted on a rim conforming to TRA, and this wheel was mounted on the front wheel of the wheel loader. The air pressure was set to 425 kPa under a high pressure condition, and when the tire was used at a crushed stone site, the time until a bead failure due to peeling of the carcass layer occurred was examined. The bead failure caused by the peeling of the carcass layer can be visually confirmed. The front wheel load at the crushed stone site was 160% of the regular load determined by the standard during chipping and 100% during traveling.
The bead durability of a tire was evaluated on the basis of the time until the occurrence of a bead failure, in four grades divided into the following four grades.

Time until bead failure ・Level A: over 4000 hours ・Level B: over 2500 hours and under 4000 hours ・Level C: over 1000 hours and under 2500 hours ・Level D: under 1000 hours

Regarding the manufactured tires, the structure of the innermost bead core and the presence/absence of the nylon chafer were variously changed based on the tire having the structure shown in FIGS.
In the conventional example, since the inner bead core has a quadrangular outline shape, there is no maximum bead wire row. On the other hand, in Comparative Examples and Examples 1 to 8, the inner bead core 5a had a hexagonal shape, and in Examples 9 to 12, the inner bead core 5a had a triangular shape and the maximum bead wire row was provided. The number of bead wires arranged was gradually changed so that the sides of the hexagonal shape and the triangular shape of the contour were substantially straight lines. The contour shapes of the bead cores 5b and 5c in the comparative example and Examples 1 to 12 were quadrangular shapes.
In Example 12, as shown in FIG. 2, nylon chafers 20 and 22 were provided.
The number of stages of the bead wire row of the inner bead core in the conventional example, the comparative example, and Examples 1 to 12 was 16, and the number of bead wires arranged in the maximum bead wire row was 16.
Tables 1 to 3 below show the tire specifications and the evaluation results.

From the comparison of the conventional example, the comparative example, and the example 1, in the innermost bead core 5a, the inclination angle θ of the carcass layer 17 is set to 10 or more, and the maximum bead wire row 16 located inside the outermost bead wire row 14 in the tire radial direction. By providing, the bead durability level is improved.
Further, from the comparison of Examples 1 to 3, the bead durability level becomes higher as the inclination angle θ of the carcass layer 17 in the innermost bead core 5a is set to 10 degrees or more and the inclination angle θ is increased within the range of 10 degrees to 30 degrees. You can see that it will improve.
Further, from the comparison of Examples 4 to 9, it is found that the maximum bead wire row 16 is located at a step number 0.3 times or more the total number of steps of the bead wire row, and the step farther from the outermost bead wire row 14 is located. From the viewpoint of improving
Further, from the comparison of Examples 9 to 11, it is found that the number of bead wires arranged in the maximum bead wire row 16 is 1.2 times or more the number of arranged bead wires in the outermost bead wire row 14, which is an improvement in the bead durability level. From the point, it can be seen that it is preferable.
Furthermore, in the comparison between Examples 11 and 12, the bead durability level was not changed, but the running time until the occurrence of the bead failure was longer in Example 12. From this, it is understood that it is preferable to provide the nylon chafer in terms of improving the bead durability.

Although the pneumatic tire of the present invention has been described in detail above, the pneumatic tire of the present invention is not limited to the above-described embodiments or examples, and various improvements and changes are made without departing from the spirit of the present invention. Of course it is okay.

1 Pneumatic Tire 3 Carcass 3a, 3b, 3c Region 4 Belts 5, 5a, 5b, 5c Bead Core 6 Tread Rubber 7 Side Rubber 8a, 8b, 8c Bead Filler 9 Inner Liner 10 Bead Base Surface 14 Outermost Bead Wire Row 16 Maximum Bead Wire Row 17 carcass layer 18 part 19 carcass cord 50 laminated bead core 51 bead wires 52a to 52g bead wire row

Claims (4)

A pneumatic tire,
A plurality of bead cores provided in a row in the tire width direction on each of the bead portions on both sides of the pneumatic tire,
A plurality of carcass layers wrapped around each of the bead cores and folded back,
In the tread portion of the pneumatic tire, with respect to the carcass layer, a plurality of belts provided outside the tire radial direction of the pneumatic tire,
The tread portion, a tread rubber provided on the tire radial outside of the belt, and,
Each of the bead cores is a laminated bead core having a configuration in which a bead wire row in which a plurality of bead wires are arranged in a direction along a bead base surface of the bead portion makes one round on a tire circumference and a surrounding layer is stacked in a plurality of stages in a tire radial direction. And
In a tire cross section obtained by cutting the pneumatic tire in a plane including the tire rotation axis of the pneumatic tire, with respect to the innermost bead core located at the innermost side in the tire width direction among the bead cores, the bead wire row of the bead portion One of the inner bead wire rows inside the outermost bead wire row located on the outermost side in the tire radial direction in the tire radial direction has more bead wires arranged than the outermost bead wire row, and among the plurality of bead wire rows. The maximum number of bead wires in the maximum bead wire row is the maximum, the carcass layer closest to the innermost bead core of the carcass layer, in order to wind the innermost bead core from the inner side in the tire width direction. A pneumatic tire characterized in that an inclination angle of a portion approaching the innermost bead core with respect to a width center line of the innermost bead core is 10 degrees or more. The pneumatic tire according to claim 1, wherein the maximum bead wire row is located at a step of 0.3 times or more of the total number of steps of the bead wire row and at a step away from the outermost bead wire row. The pneumatic tire according to claim 1, wherein the number of arranged bead wires in the maximum bead wire row is 1.2 times or more the number of arranged bead wires in the outermost bead wire row. Inner side in the tire width direction with respect to the carcass layer wound around the innermost bead core, an organic fiber reinforced layer in which organic fibers are coated with rubber, the tire radial direction with respect to the outermost bead wire row of the innermost bead core. The pneumatic tire according to any one of claims 1 to 3, which is provided in a region outside of the.

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