JP2014104881A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire excellent in durability of a toe of bead.SOLUTION: The pneumatic tire has a rubber layer 18 on an inner surface steel chafer end 6a of a toe of bead 13. The rubber layer 18 is covered by a hard rubber chafer 7 to prevent generation of inner surface separation and air inclusion at the inner surface steel chafer end 6a. Thereby, durability of the toe of bead is improved.

Description

  The present invention relates to an improvement in a bead portion of a pneumatic tire, particularly a heavy duty pneumatic tire.

  Conventionally, there has been known a pneumatic tire in which durability of the bead portion is improved in order to prevent occurrence of air entry and separation in the bead portion of the pneumatic tire.

  In Patent Document 1 below, a bead core provided in a pair of left and right bead parts, and a carcass that extends from one bead part to the other bead part and is wound around the bead core from the inside to the outside and moored in the bead part. A ply, a bead reinforcing layer wound around a bead core via a carcass ply, and a rubber chacher disposed at least on the surface of the bead portion in contact with the rim, wherein the bead reinforcing layer is a single steel cord layer with rubber The bead reinforcement layer has a tire axially inner wrapping portion and a tire axially outer wrapping portion extending radially outward beyond the bead core, and the rubber chacher is formed of a two-piece hard and soft rubber chacher made of different blended rubbers. Hard rubber chacher with excellent fracture characteristics on the side and soft rubber with excellent adhesion characteristics on the bead toe side A heavy-duty pneumatic radial tire is shown which has a configuration in which the soft rubber chacher extends radially outward beyond the edge so that the soft rubber chacher directly covers the axially inner winding end edge of the bead reinforcement layer. .

  That is, the pneumatic tire shown in the following Patent Document 1 includes a bead reinforcing layer (corresponding to the first chacher in the present invention) wound up so as to wrap the carcass ply around the carcass ply beyond the bead core, and the bead. A rubber chacher (corresponding to the second chacher in the present invention) placed on the surface of the bead portion that is overlaid on the reinforcing layer and is in contact with the rim, and is formed of two different types of hard and soft rubber chachers In the hard and soft rubber chacher, a hard rubber chacher having excellent creep resistance characteristics is disposed on the bead heel side, and a soft rubber chafer having excellent adhesiveness and fracture characteristics is disposed on the bead toe side. By comprising in this way, since the said soft rubber chacher directly covers the edge part of the tire width direction inner side of a bead reinforcement layer, it has an effect which can prevent generation | occurrence | production of air.

  Patent Document 2 below includes a pair of bead cores and a carcass straddling a pair of bead cores in a toroidal shape, and the carcass is composed of a single carcass ply, and the carcass plies are arranged in parallel with each other. A plurality of ply cords are embedded in the coating rubber, and the carcass ply is folded around the bead core from the inner side to the outer side in the tire axial direction. Between them, a stiffener is provided to ensure the rigidity of the bead portion, and a wire chacher is disposed in close contact along the outer peripheral surface of the carcass ply in the bead portion (the surface opposite to the bead core side). Chaer has multiple steel wires arranged in parallel to each other, and these multiple cords are applied to the coating rubber. An inner liner is provided on the inner surface side of the carcass ply via a tie rubber layer, and the rubber gauge between the cord and the ply cord measured at the tire inner end of the wire chacher is the inner end of the tire. Pneumatic tire set smaller than the rubber gauge measured at the other part inside the tire radial direction (at least a part further away from the position along the wire chacher 20 mm away from the inner end of the tire) is shown. ing.

  That is, in the pneumatic tire shown in Patent Document 2 below, internal shear strain is generated at the inner end in the tire width direction of the wire chacher (corresponding to the first chacher in the present invention). By reducing the rubber gauge between the wire chacher cord and the carcass ply ply cord at the inner end, the strain can be reduced, and cracks originate from the inner end in the tire width direction. Can be suppressed. In addition, a tie rubber layer (corresponding to the second chacher in the present invention) is disposed between the inner end in the tire width direction and the inner liner disposed inside the tire of the carcass ply. As the rubber deteriorates with the environment and the running period, the rubber in the carcass layer can no longer support the internal pressure, and the inner liner disposed in the inner layer of the tire blows out from between the rough carcass cords) to prevent failure and gas Transmission can also be suppressed.

JP-A-9-123715 JP 2005-297927 A

  However, in the pneumatic tire described in Patent Document 1, the use of a soft rubber chacher is effective as an improvement that can prevent the occurrence of pneumatic entry, but the end on the inner side in the tire width direction is the starting point. There is concern about the weakness in preventing the occurrence of separation.

  Further, in the pneumatic tire described in Patent Document 2, gas transmission can be suppressed by arranging the tie rubber layer, but the thickness of the tie rubber layer needs to be 1.0 mm to 2.5 mm. There is a problem that the distortion at the inner end tends to increase, and when the distortion increases, the occurrence of separation from the inner end in the tire width direction cannot be prevented.

  Therefore, as a result of intensive research, the present inventor has arranged a rubber layer at the inner steel chacher edge in the bead portion of the pneumatic tire, and covered the rubber layer with a hard rubber chacher, thereby Invented a pneumatic tire excellent in the durability of the bead portion by preventing the occurrence of internal separation and the occurrence of pneumatic entry.

  The pneumatic tire according to claim 1 of the present invention spans between a pair of bead portions, a bead core disposed in each bead portion, and each bead core, and on the outer side in the tire radial direction around the bead core. And in a pneumatic tire comprising a carcass ply whose end is wound up on the outer side in the tire width direction, and an inner liner constituting a tire inner peripheral surface disposed on the inner side in the tire width direction of the carcass ply, A first chacher that wraps the carcass ply from the inner side to the outer side in the tire width direction is disposed, and a second chafer that wraps around the first chacher is disposed. A rubber layer softer than the second chacher is interposed between an end portion on the inner side in the tire width direction and the second chacher, and the end portion is covered with the rubber layer. Is shall.

The first chacher is formed by covering a cord arranged obliquely with respect to the tire radial direction with a topping rubber. As the cord, an extensible cord having an elastic modulus of less than about 2500 kg / mm ² and a non-extensible cord having an elastic modulus of about 2500 kg / mm ² or more are generally used. Wherein the extensible cord, elastic modulus 300~500kg / mm ² approximately nylon cord or elastic modulus organic fiber cord of a polyester cord of approximately 700~900kg / mm ² is typical. Further, inextensible cord is commonly used in the heavy duty pneumatic tire, an organic aromatic polyamide cord etc. of about 2500~5000kg / mm ² is the elastic modulus 15000~20000kg / mm ² approximately of the steel cord and elastic modulus A fiber cord is used, and the steel cord covered with a topping rubber is called a steel chafer or a wire chacher.

  As said 2nd chafer, the hard rubber chacher excellent in the creep-proof characteristic is arrange | positioned. For example, a rubber composition in which the rubber components are butyl rubber and / or halogenated butyl rubber total 20 to 40% by weight, and cis-1,4-polyisoprene rubber and epoxidized cis, 4-polyisoprene rubber are total 80 to 60% by weight. There are things using things and those whose main part is composed of diene rubber with high elastic modulus, and it is simply called rubber chacher.

  Hereinafter, in the present specification, the “first chacher” is referred to as “steel chacher”, and the “end portion on the inner side in the tire width direction in the first chacher” is referred to as “inner steel chacher end”. The “second chacher” is called “hard rubber chacher”.

  Usually, the separation starting from the inner steel chaker end is large, but the inner steel chacher end is covered with a hard rubber chafer as described above, so that deformation of the steel chacher is suppressed, and the inner steel chaker end Since the thickness on the side increases, distortion at the end of the inner steel chacher is reduced, and separation between the steel chafer and the hard rubber chacher is suppressed by these actions.

  Also, in the case of only the above configuration, there is a risk that air will enter near the end of the inner steel chacher, and there is a risk of poor adhesion between the carcass ply and the hard rubber chacher. However, the construction of the rubber layer between the hard rubber chacher and the inner steel chacher edge prevents the air from entering, and the steel chafer and the rubber layer. The adhesion between the rubber layer and the hard rubber chafer is good, so that the integrity of the entire three layers is improved, and the contact between the inner steel chaker edge and the hard rubber chacher can be prevented.

  A pneumatic tire according to a second aspect of the present invention is the pneumatic tire according to the first aspect, wherein the rubber layer between the tip of the inner steel chacher end on the hard rubber chacher side and the hard rubber chacher is provided. The thickness is 0.4 mm to 1.0 mm.

  If the thickness of the rubber layer is less than 0.4 mm, cracks from the inner steel chacher edge may occur. On the other hand, when the thickness of the rubber layer exceeds 1.0 mm, the thickness becomes more than necessary, which increases the mass and increases the cost.

  Furthermore, the pneumatic tire according to claim 3 according to the present invention is the pneumatic tire according to claim 1 or 2, wherein the distance between the tip on the hard rubber chacher side and the surface of the inner liner at the inner steel chaker end. Is 3.0 mm to 6.0 mm.

  If the distance is less than 3.0 mm, cracks may occur due to insufficient durability. Moreover, since it will become thickness more than necessary when said space | interval exceeds 6.0 mm, mass will increase and cost will become high.

  Furthermore, the pneumatic tire according to claim 4 according to the present invention is the pneumatic tire according to any one of claims 1 to 3, wherein the inner surface steel chaker edge and the uppermost end of the rubber layer are provided. The distance is 10 mm to 40 mm.

  If the above distance is less than 10 mm, the carcass ply and the hard rubber chacher are likely to be peeled off due to poor adhesion, and air may enter. By improving the adhesion by arranging a rubber layer of 10 mm or more Air entry can be suppressed. On the other hand, when the distance exceeds 40 mm, the thickness becomes more than necessary, the mass increases, and the cost increases.

  Moreover, the pneumatic tire of Claim 5 which concerns on this invention is a pneumatic tire of any one of the said Claims 1-4, The distance of an inner surface steel chacher edge and the lowest end of a rubber layer Is 10 mm to 40 mm.

  If the distance is less than 10 mm, the distortion between the hard rubber and the hard rubber of the steel chacher increases, and there is a risk of separation between the two chafers. By doing so, distortion deformation is suppressed. On the other hand, when the distance exceeds 40 mm, the thickness becomes more than necessary, the mass increases, and the cost increases.

  Furthermore, the pneumatic tire according to claim 6 according to the present invention is the pneumatic tire according to any one of claims 1 to 5, wherein the hard rubber chacher is a rubber material having a 100% modulus of 5 MPa or more. It is characterized by using.

  Since the pneumatic tire of the present invention is configured as described above, it is possible to prevent the occurrence of air entry and separation in the bead part without increasing the mass and cost more than necessary, so the durability of the bead part is improved. To do.

1 is a partially omitted half cross-sectional view in the tire radial direction of a tire according to Example 1 of the present invention. FIG. 2 is a partially omitted cross-sectional view of only a bead portion in FIG. 1. FIG. 3 is a partially enlarged omitted sectional view of FIG. 2. FIG. 6 is a partially omitted cross-sectional view of only a bead portion in a tire according to Example 2 of the present invention. FIG. 5 is a partially enlarged omitted sectional view of FIG. 4. 4 is a partially omitted cross-sectional view of only a bead portion in a tire of Conventional Example 1. FIG. 10 is a partially omitted cross-sectional view of only a bead portion in a tire of Comparative Example 3. FIG.

  Preferred embodiments of a pneumatic tire and rim assembly according to the present invention will be described below in detail with reference to the accompanying drawings.

  The steel chacher in the embodiment of the present invention is formed by coating a steel cord with a topping rubber, but is not limited to this. The hard rubber chacher in the embodiment of the present invention has a 100% modulus of 5 MPa, but is not limited thereto. Furthermore, although the rubber layer in the Example of this invention is 100% modulus 3.6MPa, it is not restricted to this, What is necessary is just a rubber layer softer than a hard rubber chacher.

  1 to 3 show a first embodiment. As shown in FIG. 1, the pneumatic tire T according to the present embodiment mainly includes a tread portion 1 that constitutes a tread surface that is a circumferential surface of the tire, and a tire radial direction inward from both ends in the tire width direction of the tread portion 1. A pair of sidewall portions 2 constituting the side surface of the tire continuously formed on the side, and a pair of bead portions 13 formed continuously on the inner side in the tire radial direction at the lower end of each sidewall portion 2 It consists of.

  The tire T incorporates a carcass ply 4 so as to straddle between the bead cores 3 a across the tread portion 1, the sidewall portion 2, and the bead portion 13, and in the bead portion 13, the carcass ply 4 corresponds to each bead core. The wind-up end 4a is positioned on the outer side in the tire radial direction of each bead core 3a and on the outer side in the tire width direction. The carcass ply 4 is formed by covering a carcass ply cord arranged in a direction substantially orthogonal to the tire circumferential direction with a topping rubber. As carcass ply cords, steel cords may be suitably used in heavy duty pneumatic tires, but are not limited to these, and organic fiber cords such as polyester, rayon, nylon, and aramid are used. There is also a case.

  The tire T is provided with an inner liner 5 that constitutes the inner peripheral surface of the tire T on the inner side in the tire width direction of the carcass ply 4 in order to prevent the gas filled in the tire from passing therethrough. Yes.

  As shown in FIG. 2, the tire T according to the present embodiment wraps the carcass ply 4 in the bead portion 13 around the bead core 3 a from the inner side in the tire width direction to the outer side in the bead portion 13. The steel chafer (first chacher) 6 is provided. Reference numeral 6a denotes one end portion of the steel chacher 6 positioned on the inner side in the tire width direction, that is, an inner steel chacher end (an end portion on the inner side in the tire width direction of the first chacher). The steel chacher 6 is formed, for example, by covering a cord arranged at an angle of 20 to 50 ° with a topping rubber when the specified rim is mounted in the tire radial direction. As the cord, a steel cord is used from the viewpoint of enhancing the reinforcing effect, but an organic fiber cord may be used depending on the use of the tire.

  Further, the tire T in the present embodiment includes a hard rubber chacher (second chafer) 7 disposed in the bead portion 13 so as to wrap around the steel chacher 6. The hard rubber chacher 7 is composed of, for example, a diene rubber having a high elastic modulus at the main part, and a rubber having a 100% modulus of 5 MPa is used.

  A rubber layer 18 that is softer than the hard rubber chacher 7 is disposed between the inner surface steel chaker end 6 a and the hard rubber chafer 7, and the inner surface steel chaker end 6 a is covered with the rubber layer 18 by the rubber layer 18. In addition, the inner steel chacher end 6 a is configured not to contact the hard rubber chafer 7.

  As shown in FIG. 3, the rubber layer 18 in the present embodiment has a crescent-shaped cross section covering the inner surface steel chaker end 6a. Further, the thickness 1A of the rubber layer 18 between the tip 6b of the inner surface steel chaker end 6a on the hard rubber chacher 7 side and the hard rubber chacher 7 is 0.6 mm. The thickness 1A of the rubber layer 18 may be in the range of 0.4 mm to 1.0 mm. Further, the distance 1B between the tip 6b of the inner surface steel chaker end 6a and the surface of the inner liner 5 is 4.0 mm. The interval 1B may be in the range of 3.0 mm to 6.0 mm. A distance 1C between the inner surface steel chaker end 6a and the tire radial direction uppermost end 18a of the rubber layer 18 is 20 mm. The distance 1C may be in the range of 10 mm to 40 mm. The distance 1D between the inner surface steel chaker end 6a and the lowermost end 18b in the tire radial direction of the rubber layer 18 is 20 mm. The distance 1D may be in the range of 10 mm to 40 mm.

  Since the pneumatic tire T of the present embodiment is configured as described above, the inner steel chacher end 6a is covered with the hard rubber chacher 7, so that the deformation of the steel chacher 6 is suppressed, and the inner steel chacher end. Since the thickness on the 6a side is increased, the strain at the inner steel chacher end 6a is reduced, and the separation between the steel chafer 6 and the hard rubber chacher 7 is suppressed by these actions. Further, the rubber layer 18 is arranged between the hard rubber chafer 7 and the inner steel chacher end 6a, and the relative positional relationship between the rubber layer 18, the hard rubber chafer 7, the inner steel chaker end 6a and the inner liner 5 is as follows. By limiting the numerical values as in the embodiment, the mass and cost do not increase more than necessary, the occurrence of air entry is prevented, the adhesiveness between the steel chafer 6 and the rubber layer 18, and the rubber layer 18 and the hard rubber chafer 7 The adhesion of the three layers is improved, and the contact between the inner steel chacher edge 6a and the hard rubber chacher 7 can be prevented, so that the durability of the bead portion 13 is improved. It becomes a pneumatic tire T.

  The second embodiment is a modification of the rubber layer 18 in the bead portion 13 in the first embodiment. Therefore, since Example 2 is the same as that of Example 1 about structures other than the rubber layer 18, description of Example 1 is used and the description is abbreviate | omitted.

  4 and 5 show the second embodiment. As shown in FIG. 4, in this embodiment, a rubber layer 28 that is softer than the hard rubber chacher 7 is disposed between the inner surface steel chaker end 6a and the hard rubber chacher 7 in the bead portion 23. The inner steel chacher end 6 a is covered with the rubber layer 28 by the rubber layer 28, and the inner steel chacher end 6 a is configured not to contact the hard rubber chafer 7.

  As shown in FIG. 5, the rubber layer 28 in the present embodiment is in the form of a sheet that covers the inner surface steel chaker end 6a. That is, one end portion 28 c of the sheet-like rubber layer 28 is sandwiched between the carcass ply 4 and the hard rubber chafer 7, and the other end portion 28 d is interposed between the steel chafer 6 and the hard rubber chafer 7. The intermediate portion 28 e is sandwiched between the inner surface steel chaker end 6 a and the hard rubber chacher 7.

  Further, the thickness 2A of the rubber layer 28 between the end 6b of the inner steel chaker end 6a on the hard rubber chacher 7 side and the hard rubber chacher 7 is 0.6 mm. The rubber layer 28 may have a thickness 2A in the range of 0.4 mm to 1.0 mm. Further, the distance 2B between the tip 6b of the inner surface steel chaker end 6a and the surface of the inner liner 5 is 4.0 mm. The interval 2B may be in the range of 3.0 mm to 6.0 mm. The distance 2C between the inner surface steel chaker end 6a and the tire radial direction uppermost end 28a of the rubber layer 28 is 20 mm. The distance 2C may be in the range of 10 mm to 40 mm. The distance 2D between the inner surface steel chaker end 6a and the lowermost end 28b in the tire radial direction of the rubber layer 28 is 30 mm. The distance 2D may be in the range of 10 mm to 40 mm.

  Since the bead portion 23 of the pneumatic tire of the present embodiment is configured as described above, the inner steel chacher end 6a is covered with the hard rubber chacher 7, so that the deformation of the steel chacher 6 is suppressed, and the inner steel Since the thickness on the side of the chacher end 6a is increased, the distortion at the inner surface steel chacher end 6a is reduced, and the separation between the steel chafer 6 and the hard rubber chacher 7 is suppressed by these actions. Further, the rubber layer 28 is disposed between the hard rubber chafer 7 and the inner steel chacher end 6a, and the relative positional relationship between the rubber layer 28, the hard rubber chafer 7, the inner steel chaker end 6a and the inner liner 5 is shown. By limiting the numerical values as in the embodiment, the mass and cost do not increase more than necessary, the occurrence of air entry is prevented, the adhesiveness between the steel chafer 6 and the rubber layer 28, and the rubber layer 28 and the hard rubber chafer 7 The adhesion of the three layers is improved and the contact between the inner steel chacher edge 6a and the hard rubber chacher 7 can be prevented, so that the durability of the bead portion 23 is improved. It becomes a pneumatic tire.

  Next, with respect to Conventional Example 1, Comparative Examples 1 to 3, Example 1 and Example 2, a comparative test was performed as follows, and durability of bead portions 13 and 23 in Examples 1 and 2 was improved. Explain that.

[Configuration of Conventional Example 1]
The bead portion 103 of Conventional Example 1 shown in FIG. 6 has an inner steel chacher end 106a covered with an inner liner 105, and a lower portion 106b of the steel chacher on the outer side in the tire width direction from below the inner steel chacher end 106a It is covered with the hard rubber chacher 107a, and the rubber layer is not arranged.

[Configuration of Comparative Example 1]
Although not shown in the figure, the bead portion of Comparative Example 1 is covered with a soft rubber chacher from the inner steel chaker edge to the lower portion of the steel chacher on the outer side in the tire width direction, and no rubber layer is disposed. Is.

[Configuration of Comparative Example 2]
Although the illustration of the bead portion of Comparative Example 2 is omitted, the inner steel chaker end is covered with an inner liner, and the lower portion of the steel chacher on the outer side in the tire width direction from the lower side of the inner steel chacher end is a hard rubber chafer. It is covered and a rubber layer is arranged.

[Configuration of Comparative Example 3]
The bead portion 203 of Comparative Example 3 shown in FIG. 7 is covered with a hard rubber chafer 207a from the inner steel chacher end 206a to the lower portion 206b of the steel chacher on the outer side in the tire width direction, and the rubber layer is disposed. It is not.

[Comparison test]
Under the following conditions, a comparative test was performed on the above-described Conventional Example 1, Comparative Examples 1 to 3, Example 1 and Example 2.

Test tire: 295 / 75R22.5
A test tire with a rim size of 22.5 × 8.25 and an air pressure of 700 kPa was attached to the indoor test machine, and a running test was performed under conditions of a speed of 40 km / h and a load load of 5500 kg. Thereafter, the separation length of the inner steel chacher edge when the traveling distance is 8000 km is measured. The evaluation result means that when the conventional example 1 is “100”, the larger the index value is, the more the separation is suppressed.

As a result of the above comparative test, the inner steel chacher end is covered with a hard rubber chacher, that is, Comparative Example 3, Example 1 and Example 2 are not covered with the hard rubber chafer. Compared to Conventional Example 1 and Comparative Example 2, the separation was significantly suppressed. Moreover, although the comparative example 3 resulted in the suppression being significantly suppressed, since a rubber layer was not disposed between the end of the inner surface steel chacher and the hard rubber chacher, occurrence of inner surface air was confirmed.

  In addition, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

T ......... Pneumatic tire 1 ......... Tread part 2 ......... Side wall part 13 ... Bead part 3a ... Bead core 4 ......... Carcass ply 4a ... Carcass ply winding end 5 ... Inner liner 6 ……… Steel Chacher (First Chacher)
6a ...... Inner steel chacher end (end on the inner side in the tire width direction of the first chafer)
7 ……… Hard rubber chacher (second chacher)
18 ... Rubber layer 18a ... Rubber layer tire radial uppermost end 18b ... Rubber layer tire radial lowermost end 1A ... Rubber layer thickness 1B between inner steel chacher edge tip and hard rubber chafer ... Inner surface The distance between the tip of the steel chaker end and the surface of the inner liner is 1C. The distance between the inner steel chaker end and the top end of the rubber layer in the tire radial direction is 1D. Distance from lower end 23... Bead portion 28... Sheet-like rubber layer 28 c... One end portion of sheet-like rubber layer (between carcass ply and hard rubber chafer 7)
28d ... the other end of the sheet-like rubber layer (between the steel chafer and the hard rubber chacher)
28e ... Intermediate part of sheet-like rubber layer (between inner steel chaker edge and hard rubber chacher)
2A …… Rubber layer thickness between the tip of the inner steel chacher end and the hard rubber chafer 2B …… Distance between the tip of the inner steel chacher end and the inner liner surface 2C …… End of the inner steel chacher end and the rubber layer The distance 2D between the tire radial direction uppermost end of the tire and the inner steel chacher end and the rubber layer lowermost in the tire radial direction 103. The bead portion 106a. The inner steel chafer end 105. The inner liner 106b. The lower part 107a of the her ... Hard rubber chacher 203 ... The bead part 206a ... The inner steel chacher end 206b ... The lower part 207a of the steel chacher ... The hard rubber chacher

Claims (6)

A pair of bead portions, a bead core disposed in each beat portion, and a carcass ply that straddles between the bead cores, and ends are rolled up outward in the tire radial direction and outward in the tire width direction around the bead core. And a pneumatic tire comprising an inner liner that constitutes a tire inner peripheral surface disposed on the inner side in the tire width direction of the carcass ply,
A first chacher that wraps around the rolled-up portion of the carcass ply from the inner side to the outer side in the tire width direction in the bead portion;
Disposing a second chacher surrounding the first chacher;
A rubber layer softer than the second chacher is interposed between an end portion on the inner side in the tire width direction of the first chafer and the second chacher, and an end on the inner side in the tire width direction by the rubber layer Pneumatic tire characterized by covering the part.   The thickness of the rubber layer between the second chacher tip and the second chacher at the end on the inner side in the tire width direction of the first chacher is 0.4 mm to 1.0 mm. The pneumatic tire according to claim 1.   The distance between the tip on the second chacher side and the inner liner surface at the end on the inner side in the tire width direction of the first chacher is 3.0 mm to 6.0 mm. Pneumatic tire described in 2.   The distance between the end portion on the inner side in the tire width direction of the first chacher and the uppermost end in the tire radial direction of the rubber layer is 10 mm to 40 mm. 5. Pneumatic tire.   The distance between the end portion on the inner side in the tire width direction of the first chacher and the lowermost end in the tire radial direction of the rubber layer is 10 mm to 40 mm. 5. Pneumatic tire.   The pneumatic tire according to any one of claims 1 to 5, wherein the second chafer is made of a rubber material having a 100% modulus of 5 MPa or more.

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