JP2007216752A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve run-flat durability without obstructing various performance such as driving comfortability, etc. and deteriorating uniformity. <P>SOLUTION: A folding-back end 16b of a carcass layer 16 is arranged at a position separated by more than 5mm and less than 15mm in a straight line distance from an end part 15c in the cross direction of a belt layer 15 arranged on an end part in the cross direction of a tread part 12, and at the position where a distance P in the tire diametrical direction from a rim base B becomes more than 65% and less than 85% of a distance SH in the tire diametrical direction of the rim base B and a tread part 12a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pneumatic tire used as a run-flat tire that can travel a predetermined distance even when an abnormal decrease in tire internal pressure occurs or during a puncture.

This type of pneumatic tire generally includes a pair of left and right bead portions as shown in, for example, Patent Documents 1 to 4 below, and a tread portion that is disposed on the outer side in the tire radial direction of the bead portion and includes a tread surface portion of the tire. And a buttress portion provided at each of both ends in the width direction of the tread portion, and a sidewall portion connecting the buttress portion and the bead portion, the bead portion, the sidewall portion, the buttress portion, and the tread portion. A carcass layer extending in a toroidal manner between the bead cores embedded in the pair of left and right bead portions is provided inside each of these portions, and both ends of the carcass layer are connected to the tire width via the bead cores. It is a folded end that is folded back from the inner side to the outer side, and the width direction end is between the crown portion of the carcass layer and the tread surface portion. There is a belt layer is provided so as to be arranged in the widthwise direction end portions of the tread portion, crescent cross-sectional shape of the reinforcing rubber in the tire width direction inner side of the carcass layer is known arrangement provided in the side wall portion.
In recent years, in order to increase the distance in which run-flat traveling is possible, that is, to improve the run-flat durability, for example, the thickness of the reinforcing rubber is increased, or the width of the carcass layer is increased to increase the distance. By increasing the height and making the folded end reach just below the end in the width direction of the belt layer, it is possible to suppress the amount of deflection toward the outside in the tire width direction of the sidewall during run-flat running. It is being considered. Here, when the folded end is disposed at a position where the distance in the tire radial direction from the rim base is greater than 85% of the distance in the tire radial direction between the rim base and the tread surface portion, the folded end substantially becomes a belt. It will reach even directly below the widthwise end of the layer.
Japanese Patent Laid-Open No. 02-283508 JP 2000-168319 A JP 2003-154821 A JP 09-58229 A

However, when the thickness of the reinforcing rubber is increased as described above, the elastic coefficient in the direction in which the tire receives the load of the vehicle, that is, the tire radial direction increases, and the ratio of the viscous characteristic to the mechanical properties of the tire decreases. As a result, the tires cannot absorb shocks and vibrations from the road surface, hindering a comfortable ride, increasing the load on the vehicle, reducing the durability of the vehicle, and increasing the generated noise. There was a risk of causing it. Furthermore, in this case, the thickness of the reinforcing rubber is increased, so the dimensional accuracy is likely to vary in the tire circumferential direction, making it difficult to ensure rigidity and weight uniformity throughout the tire circumferential direction (deterioration of uniformity). ), There is a risk of increasing the above-described impediment to comfortable riding.
On the other hand, when the folded end of the carcass layer reaches just below the end in the width direction of the belt layer, the folded end of the carcass layer can improve the rigidity against the deformation of the side wall portion. On the other hand, since the folding height of the carcass layer becomes high, it is difficult to make the folding height uniform over the entire circumference of the tire, and there is a possibility that the uniformity is deteriorated. Furthermore, the rigidity becomes too high, and there is a possibility that the comfortable riding comfort is hindered.

  The present invention has been made in consideration of such circumstances, and a pneumatic tire capable of improving run-flat durability without impairing a comfortable riding comfort or deteriorating uniformity. The purpose is to provide.

  In order to solve the above-described problems and achieve such an object, the pneumatic tire of the present invention includes a pair of left and right bead portions and a tire tread surface portion disposed radially outward of the bead portions. Having a tread portion, buttress portions provided at both ends in the width direction of the tread portion, and sidewall portions connecting the buttress portion and the bead portion, the bead portion, the sidewall portion, and the buttress portion. A carcass layer extending in a toroid shape is provided between the bead cores embedded in the pair of left and right bead parts, and both ends of the carcass layer are respectively interposed via the bead cores. The folded end portion is folded back from the inner side to the outer side in the tire width direction, and the width direction between the crown portion of the carcass layer and the tread surface portion is A pneumatic tire in which a belt layer is provided so that a portion is disposed at an end in a width direction of a tread portion, and a crescent-shaped reinforcing rubber is provided in a tire width direction inside of a carcass layer in a sidewall portion, The folded end of the folded end is a position where the distance in the tire radial direction from the rim base is 65% to 85% of the distance in the tire radial direction between the rim base and the tread surface, and the width direction of the belt layer It is arranged at a position away from the end by a straight line distance of 5 mm or more and 15 mm or less.

In the present invention, the folded end of the carcass layer is such that the distance in the tire radial direction from the rim base is 65% to 85% of the distance in the tire radial direction between the rim base and the tread portion (hereinafter referred to as “section height”). And a bead core in the carcass layer without excessively increasing the folded height of the carcass layer. The part located on the outer side in the tire width direction can effectively increase the rigidity against the deflection deformation of the sidewall part toward the outer side in the tire width direction, suppressing the deterioration of the tire uniformity and the run-flat durability. Can be improved. Furthermore, an increase in the weight of the pneumatic tire can be suppressed.
Further, since the rigidity of the sidewall portion can be increased by the carcass layer, the contribution of the reinforcing rubber to the rigidity is reduced by this reinforced amount, for example, the thickness of the reinforcing rubber is reduced. In addition, the elastic modulus of the reinforcing rubber can be reduced, and the proportion of the viscosity characteristic in the mechanical properties of the tire can be prevented from being reduced. Therefore, it becomes possible to make the tires easily absorb shocks and vibrations from the road surface, preventing a comfortable ride comfort, reducing the durability of the vehicle, and further increasing the generated noise. be able to. Furthermore, when the thickness of the reinforcing rubber is reduced as described above, it becomes possible to suppress variation in the dimensional accuracy in the tire circumferential direction, and it is possible to more reliably suppress deterioration of uniformity. it can.

  Here, in the bead portion, a fiber reinforced layer folded back from the inner side in the tire width direction so as to surround the inner side in the tire radial direction of the bead core is embedded, and a rim base and a folded end on the outer side in the tire width direction of the fiber reinforced layer, The distance in the tire radial direction is 30% to 50% of the distance in the tire radial direction between the rim base and the tread surface portion, and the distance in the tire radial direction between the rim base and the inner end of the fiber reinforced layer in the tire width direction. May be 60% or more and less than 75% of the distance between the rim base and the tread surface portion in the tire radial direction.

In this case, the portion of the fiber reinforced layer located on the inner side in the tire width direction than the bead core extends outward in the tire radial direction to the position facing the reinforcing rubber in the tire width direction. It is possible to increase the rigidity against the bending deformation of the reinforcing rubber and the carcass layer not only by the portion positioned on the outer side in the tire width direction from the bead core but also by the fiber reinforced layer. Therefore, it is possible to further reduce the contribution of the reinforcing rubber to the rigidity, and the above-described operational effects are reliably exerted. Furthermore, since it is possible to reduce the size of the bending deformation of the sidewall portion, it becomes possible to suppress the shearing force generated in the carcass layer during run-flat traveling, and the carcass layer is made of reinforcing rubber or the like. Can be prevented from peeling off, and the run-flat durability can be further improved.
Here, when the distance in the tire radial direction between the rim base and the folded end on the inner side in the tire width direction of the fiber reinforced layer is smaller than 60% of the section height, the fiber reinforced layer increases the rigidity against the deflection deformation of the sidewall portion. I can't. Further, if the distance in the tire radial direction between the rim base and the folded end on the inner side in the tire width direction of the fiber reinforced layer is greater than 75% of the section height, the folded end of the fiber reinforced layer is caused to run on the side wall portion during run flat running. There is a risk of being located at a location where the shearing force is maximized.In this case, the folded end of the fiber reinforced layer or its peripheral portion is the starting point, and the side wall is likely to crack, and the uniformity may be deteriorated. is there.
If the distance in the tire radial direction between the rim base and the folded end on the outer side in the tire width direction of the fiber reinforced layer is smaller than 30% of the section height, the folded end of the fiber reinforced layer is mounted when the tire is mounted on a vehicle. Is positioned radially inward from the outer peripheral edge of the rim flange, and the folded end of the fiber reinforced layer is pressed toward the inner side in the width direction of the tire by the inner surface of the outer peripheral portion of the rim flange. In this case, the folded end on the outer side in the tire width direction of the fiber reinforced layer or its peripheral portion is likely to generate heat, and the run-flat durability may be reduced. Furthermore, if the distance in the tire radial direction between the rim base and the folded end on the outer side in the tire width direction of the fiber reinforced layer is larger than 50% of the section height, the rigidity of the side wall portion against the deflection deformation becomes excessively high. This may hinder a comfortable ride and increase the load on the vehicle, which may reduce the durability of the vehicle, increase the generated noise, and may deteriorate the uniformity.

  Further, in the carcass layer, a plurality of carcass cords extending in a certain direction are buried in a state of being arranged at predetermined intervals in a direction orthogonal to the certain direction, and the fiber reinforcing layer has a certain direction. The carcass cords and reinforcements that are embedded in a plurality of reinforced fibers extending in the direction perpendicular to the predetermined direction and arranged in a state spaced apart from each other at a predetermined interval and facing each other on the inner and outer sides in the tire width direction across the bead core The fibers may extend at an angle of 45 ° or more and 90 ° or less with respect to each other in a plan view of the carcass layer and the fiber reinforced layer.

  In this case, since the carcass cord and the reinforcing fiber extend at an angle of 45 ° or more and 90 ° or less as described above, the size of the mesh that the carcass cord and the reinforcing fiber define in the plan view. Becomes finer. Therefore, when the side wall portion tries to bend toward the outer side in the tire width direction, this bending deformation of the portion located on the inner side in the tire width direction than the bead core in the carcass layer located on the side wall portion is fiber reinforced. It becomes possible to suppress by the part located in the tire width direction inner side than the bead core in the layer, it becomes possible to further improve the rigidity with respect to the deflection deformation of the sidewall part, and the above-mentioned effects are surely exerted. It will be.

Further, the bead portion includes a bead filler extending from the bead core side toward the outer side in the radial direction of the tire, and the distance between the radially outer end of the bead filler and the rim base in the tire radial direction is the rim base and the tread surface portion. And 40% or more and 55% or less of the distance in the tire radial direction.
In this case, the above-described effects are surely achieved.

  According to the present invention, the run-flat durability can be improved without impairing a comfortable ride comfort or the like or deteriorating uniformity.

  Hereinafter, an embodiment of a pneumatic tire according to the present invention will be described with reference to FIG. FIG. 1 shows a part of a cross-sectional view of a pneumatic tire 10, which includes a pair of left and right bead portions 11 and a tread surface portion 12 a of the tire that is disposed outwardly in the tire radial direction of the bead portions 11. The tread portion 12 is provided, buttress portions 12b provided at both ends of the tread portion 12 in the width direction, and sidewall portions 13 that connect the buttress portions 12b and the bead portions 11 to each other.

  And inside the bead part 11, the side wall part 13, the buttress part 12b, and the tread part 12, the carcass extended in the toroid form between the bead cores 11a respectively embedded in the pair of left and right bead parts 11 over these parts. A layer 16 is provided, and both end portions of the carcass layer 16 are turned-back end portions 16a that are turned back from the inner side 10a to the outer side 10b via the bead core 11a. A belt layer 15 is provided between the crown portion 16 c of the carcass layer 16 and the tread surface portion 12 a so that the width direction end portion is disposed at the width direction end portion of the tread portion 12.

  Further, a reinforcing rubber 17 having a crescent-shaped cross section is provided on the inner side in the tire width direction of the carcass layer 16 in the side wall portion 13, thereby providing rigidity against bending deformation toward the outer side in the tire width direction of the side wall portion 13. This is a run-flat tire that is increased and can travel a predetermined distance even when the tire internal pressure is abnormally lowered or punctured.

  In the present embodiment, the belt layer 15 includes a first belt 15a disposed on the outer side in the tire radial direction, a width wider than the first belt 15a, and an inner side in the tire radial direction than the first belt 15a. And a second belt 15b. Further, a rim guard 19 that protrudes outward in the tire width direction is provided at the boundary between the bead portion 11 and the sidewall portion 13, and the rim guard 19 is positioned on the inner side in the tire radial direction so as to be outside the tire width direction. The outer peripheral portion of the rim flange 20 is fitted into a portion extending from the rising surface 19a rising toward the inner side in the tire radial direction of the bead portion 11 so that the pneumatic tire 10 is mounted on the vehicle. Yes.

  Here, the turning end 16b of the turning end portion 16a of the carcass layer 16 has a distance P in the tire radial direction from the rim base B that is a distance in the tire radial direction between the rim base B and the tread surface portion 12a (hereinafter referred to as "section height"). ) A linear distance from the width direction end 15c (width direction end of the belt layer 15) of the second belt 15b disposed at the position where the SH is 65% or more and 85% or less and is located at the width direction end of the tread portion 12. They are arranged at positions 5 mm or more and 15 mm or less (distance D) apart. The folded end 16b is located on the outer side 10b in the tire width direction and on the inner side in the tire radial direction than the end 15c in the width direction of the second belt 15b.

  Furthermore, in the present embodiment, a fiber reinforced layer 18 that is folded back from the tire width direction inner side 10a to the outer side 10b is embedded in the bead portion 11 so as to surround the inner side of the bead core 11a in the tire radial direction. Reinforcing fibers extending in a certain direction are embedded in the fiber reinforced layer 18 in a state in which a plurality of reinforcing fibers are arranged at predetermined intervals in a direction orthogonal to the certain direction. For example, an aramid fiber can be used as the reinforcing fiber.

  The distance L in the tire radial direction between the rim base B and the turn-back end 18a on the outer side 10b in the tire width direction of the fiber reinforced layer 18 is 30% to 50% of the section height SH. Further, the distance H in the tire radial direction between the rim base B and the folded end 18b on the inner side 10a in the tire width direction of the fiber reinforced layer 18 is 60% or more and less than 75% of the section height SH. That is, the fiber reinforced layer 18 has a folded end 18a on the outer side 10b in the tire width direction located on the outer side in the tire radial direction than the rim guard 19, and a folded end 18b on the inner side 10a in the tire width direction is the most in the crescent-shaped reinforcing rubber 17. It is located outside the tire radial direction than the thick part.

  Here, a plurality of carcass cords extending in a certain direction are embedded in the carcass layer 16 in a state in which a plurality of carcass cords are arranged at predetermined intervals in a direction orthogonal to the certain direction. In each of the tire inner side 10a and the outer side 10b sandwiching the bead core 11a, the carcass cord and the reinforcing fiber facing each other have an angle of 45 ° or more and 90 ° or less with respect to each other in a plan view of the carcass layer 16 and the fiber reinforcing layer 18. It doesn't extend.

  Further, the bead portion 11 includes a bead filler 11b extending from the bead core 11a toward the outer side in the radial direction of the tire. A distance X between the radial outer end 11c of the bead filler 11b and the rim base B in the tire radial direction is: , 40% or more and 55% or less of the section height SH.

  As described above, according to the pneumatic tire 10 according to the present embodiment, the distance P in the tire radial direction from the rim base B of the folded end 16b of the carcass layer 16 is 65% or more and 85% or less of the section height SH. And the carcass layer 16 without being excessively increased in the folded height of the carcass layer 16 because the carcass layer 16 is disposed at a position that is linearly spaced from the end 15c in the width direction of the second belt 15b by a distance of 5 mm to 15 mm. 16, the portion located on the outer side 10 b in the tire width direction than the bead core 11 a can effectively increase the rigidity of the sidewall portion 13 against the bending deformation toward the outer side 10 b in the tire width direction, and the tire uniformity is deteriorated. The run-flat durability can be improved while suppressing the above. Furthermore, an increase in the weight of the pneumatic tire 10 can be suppressed.

  Furthermore, since the rigidity of the sidewall portion 13 can be increased by the carcass layer 16, the contribution of the reinforcing rubber 17 to the rigidity is reduced by the amount of the reinforcement. For example, the thickness of the reinforcing rubber 17 It is possible to reduce the thickness of the tire and to reduce the elastic coefficient of the reinforcing rubber 17, and to prevent the proportion of the viscosity characteristic from being reduced in the mechanical properties of the tire. Therefore, it becomes possible to make the tires easily absorb shocks and vibrations from the road surface, preventing a comfortable ride comfort, reducing the durability of the vehicle, and further increasing the generated noise. be able to. Furthermore, when the thickness of the reinforcing rubber 17 is reduced as described above, the dimensional accuracy can be suppressed from varying in the tire circumferential direction, and the deterioration of uniformity can be more reliably suppressed. Can do.

  Further, the distance L in the tire radial direction between the rim base B and the folded end 18a of the outer side 10b in the tire width direction of the fiber reinforced layer 18 is 30% or more and 50% or less of the section height SH, and the rim base B and the fiber reinforced layer 18 The distance H in the tire radial direction from the turn-back end 18b of the tire width direction inner side 10a is set to 60% or more and less than 75% of the section height SH, and is located in the tire width direction inner side 10a in the fiber reinforced layer 18 from the bead core 11a. Since the portion extends outward in the tire radial direction to a position facing the reinforcing rubber 17 in the tire width direction, the rigidity against the deflection deformation toward the outer side 10b in the tire width direction of the sidewall portion 13 is reinforced. A portion of the rubber 17 and the carcass layer 16 located on the outer side 10b in the tire width direction from the bead core 11a. It is possible to increase by the fiber-reinforced layer 18 not.

  Therefore, it is possible to further reduce the contribution of the reinforcing rubber 17 to the rigidity, and the above-described operational effects are reliably exerted. Further, since the size of the deflection deformation of the sidewall portion 13 can be reduced, it is possible to suppress the shearing force generated in the carcass layer 16 during the run-flat running, and the carcass layer 16 Separation from the reinforcing rubber 17 and the like can be prevented, and run-flat durability can be further improved.

  Furthermore, in each of the tire width direction inner side 10a and the outer side 10b across the bead core 11a, the carcass cords and the reinforcing fibers facing each other are 45 ° or more and 90 ° or less with respect to each other in a plan view of the carcass layer 16 and the fiber reinforcing layer 18. Since it extends at an angle, the size of the meshes that the carcass cord and the reinforcing fiber define in the plan view can be reduced. Therefore, when the sidewall portion 13 tries to bend as described above, the deflection deformation of the portion located in the tire width direction inner side 10a than the bead core 11a in the carcass layer 16 located in the sidewall portion 13 The fiber reinforced layer 18 can be restrained by a portion located on the inner side 10a in the tire width direction than the bead core 11a, and the rigidity of the sidewall portion 13 with respect to the bending deformation can be further improved. The effect is surely achieved.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the configuration in which the first and second belts 15a and 15b are provided as the belt layer 15 is shown, but in addition to this, the second belt is located outside the first belt 15a in the tire radial direction. You may provide a belt reinforcement layer so that the width direction edge part may be arrange | positioned in the width direction edge part of the tread part 12 in the tire width direction outer side 10b rather than the width direction both ends of 15b. Then, the folded end 16b of the carcass layer 16 may be arranged at a linear distance of 5 mm or more and 15 mm or less from the width direction outer end of the belt reinforcing layer.

  Moreover, although the structure which provided the fiber reinforcement layer 18 was shown in the said embodiment, it is applicable also to the structure which does not have this reinforcement layer 18. FIG. Furthermore, the fiber reinforced layer 18 is not limited to the above-described embodiment as long as the rigidity of the fiber reinforced layer 18 against the bending deformation toward the outer side 10b of the sidewall portion 13 is increased.

  Next, the verification test about the effect demonstrated above was implemented. In this test, the size is unified at 225 / 45R17, and the distance L in the tire radial direction between the rim base B and the turn-back end 18a of the outer side 10b of the fiber reinforced layer 18 is unified to 40% of the section height SH. The distance in the tire radial direction between the rim base B and the folded end 16b of the carcass layer 16 in a state where the distance H in the tire radial direction between the rim base B and the folded end 18b on the inner side 10a in the tire width direction is unified to 70% of the section height SH. P and a plurality of types of pneumatic tires having different linear distances D between the folded end 16b of the carcass layer 16 and the width direction end 15c of the second belt 15b were employed. Each of these pneumatic tires was mounted on a vehicle separately and a verification test was performed.

  Of the test items shown in Table 1, the run-flat durability, the elastic modulus of the tire, and the uniformity are 10 mm for the reinforcing rubber 18 in the pneumatic tire not having the fiber reinforced layer 18, and the distance Evaluation was performed using an index with the data obtained when a verification test was performed with a conventional tire having 55% of the section height SH mounted on the vehicle. When the run flat durability is larger than 100, it indicates that the durability is improved as compared with the conventional tire. When the elastic modulus of the tire is smaller than 100, the tire flat tire durability is smaller than that of the conventional tire. It shows that the elastic modulus in the radial direction has been reduced. When the uniformity is greater than 100, it indicates that the uniformity has deteriorated compared to the tire of the conventional example.

As a result, as shown in Table 1, the turn-back end 16b of the carcass layer 16 is located at a position where the distance P in the tire radial direction from the rim base B is 65% or more and 85% or less of the section height SH, and the tread portion 12 It has been confirmed that the above-described effects can be reliably achieved if the linear belt is disposed at a position 5 mm or more and 15 mm or less away from the width direction end 15c of the second belt 15b disposed at the width direction end. .
Note that when the turn-back end 16b of the carcass layer 16 is disposed at a position where the distance P in the tire radial direction from the rim base B is greater than 85% of the section height SH, the turn-back end 16b has a width of the second belt 15b. Since it reaches the position directly below the end of the direction, the turn-up height of the carcass layer 16 is increased, and it becomes difficult to make the turn-up height uniform over the entire circumference of the tire, thereby deteriorating uniformity. Or the elastic modulus becomes too high.

  Next, in a state where the distance P in the tire radial direction between the rim base B and the folded end 16b of the carcass layer 16 is unified to 80% of the section height SH, the folded end of the rim base B and the fiber reinforced layer 18 on the outer side 10b in the tire width direction. A plurality of types of pneumatic tires were used in which the distance L in the tire radial direction from 18a and the distance H in the tire radial direction between the rim base B and the turned-back end 18b of the inner side 10a in the tire width direction were different. Each of these pneumatic tires was mounted on a vehicle separately, and a verification test was performed in the same manner as described above.

  As a result, as shown in Table 2, the distance L in the tire radial direction between the rim base B and the turn-back end 18a of the outer side 10b of the fiber reinforced layer 18 is 30% or more and 50% or less of the section height SH, If the distance H in the tire radial direction between the rim base B and the folded end 18b on the inner side 10a in the tire width direction of the fiber reinforced layer 18 is 60% or more and less than 75% of the section height SH, the above-described effects can be further ensured. It was confirmed to be effective.

  The run-flat durability can be improved without impairing various performances such as comfortable riding comfort or deteriorating uniformity.

1 is a partial cross-sectional view of a pneumatic tire according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 10a Tire width direction inner side 10b Tire width direction outer side 11 Bead part 11a Bead core 11b Bead filler 11c Radial outer end 12 Tread part 12a Tread part 12b Buttress part 13 Side wall part 15 Belt layer 15c 2nd Belt width direction end (belt layer width direction end)
REFERENCE SIGNS LIST 16 carcass layer 16a folded end 16b folded end 16c carcass layer 16c crown 17 reinforcing rubber 18 fiber reinforced layer 18a folded end 18b of fiber reinforced layer in the tire width direction outer fold end B in the tire width direction of the fiber reinforced layer B rim base

Claims (4)

A pair of left and right bead portions, a tread portion disposed on the outer side in the tire radial direction of the bead portion and having a tread surface portion of the tire, buttress portions respectively provided at both ends in the width direction of the tread portion, and these buttresses And a sidewall portion connecting the portion and the bead portion,
Inside the bead portion, sidewall portion, buttress portion, and tread portion, a carcass layer extending in a toroid shape is provided between the bead cores embedded in each of the pair of left and right bead portions. Both end portions of the carcass are folded end portions that are folded back from the inner side to the outer side in the tire width direction via bead cores, and the end portions in the width direction are tread portions between the crown portion of the carcass layer and the tread surface portion. A pneumatic tire in which a belt layer is provided so as to be disposed at an end in the width direction, and a crescent-shaped reinforcing rubber is provided on the inner side in the tire width direction of the carcass layer in the sidewall portion,
The folded end of the folded end is a position where the distance in the tire radial direction from the rim base is 65% to 85% of the distance in the tire radial direction between the rim base and the tread surface, and the width direction of the belt layer A pneumatic tire characterized by being arranged at a position that is 5 mm or more and 15 mm or less away from the end portion by a linear distance. The pneumatic tire according to claim 1,
In the bead portion, a fiber reinforced layer folded from the inside in the tire width direction to the outside so as to surround the inside in the tire radial direction of the bead core is embedded,
The distance in the tire radial direction between the rim base and the folded end on the outer side in the tire width direction of the fiber reinforced layer is 30% to 50% of the distance in the tire radial direction between the rim base and the tread surface portion. A pneumatic tire characterized in that the distance in the tire radial direction from the inner end in the tire width direction is 60% or more and less than 75% of the distance in the tire radial direction between the rim base and the tread surface portion. The pneumatic tire according to claim 2,
A plurality of carcass cords extending in a certain direction are embedded in the carcass layer in a direction perpendicular to the certain direction with a predetermined interval, and the fiber reinforced layer extends in a certain direction. Reinforcing fibers are embedded in a state in which a plurality of reinforcing fibers are arranged at predetermined intervals in a direction orthogonal to the certain direction,
The carcass cords and reinforcing fibers facing each other on the inner and outer sides in the tire width direction across the bead core extend at an angle of 45 ° or more and 90 ° or less with respect to each other in plan view of the carcass layer and the fiber reinforcing layer. A pneumatic tire characterized by In the pneumatic tire according to any one of claims 1 to 3,
The bead portion includes a bead filler extending from the bead core side toward the radially outer side of the tire, and a distance between the radially outer end of the bead filler and the rim base in the tire radial direction is a distance between the rim base and the tread surface portion. A pneumatic tire characterized by being 40% to 55% of the distance in the tire radial direction.

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