JP7315818B2 - pneumatic tire - Google Patents

Description

The present invention relates to pneumatic tires.

Conventionally, pneumatic tires are known that maintain low tire weight and low rolling resistance while improving steering stability on dry road surfaces (for example, Patent Document 1).

JP 2018-008620 A

By the way, in a pneumatic tire, depending on the thickness of the inner liner, air in the inner cavity may permeate the inner liner. When the air passing through the inner liner reaches the belt layer, the moisture in the air may cause rust on the metal parts of the belt layer. If the metal portion of the belt layer is rusted, separation is likely to occur between the members forming the belt layer, resulting in deterioration of durability. In many cases, the wear of the tread portion increases before such separation occurs, and it is time to replace the tire.

However, in hot regions with relatively high temperatures, the tread wears less than in regions with relatively low temperatures, so there is a possibility that the above-mentioned separation will occur before the time to replace the tire. be. Increasing the thickness of the innerliner reduces the possibility of lumen air permeating the innerliner. However, when the thickness of the inner liner is large, there arises a problem that the weight of the pneumatic tire becomes large. Moreover, it is not preferable to reduce the steering stability performance.

The present invention has been made in view of the above, and an object thereof is to provide a pneumatic tire that can achieve weight reduction and improved steering stability performance while improving durability performance in high-temperature regions.

In order to solve the above-described problems and achieve the object, a pneumatic tire according to one aspect of the present invention includes a tread portion extending in the tire circumferential direction and forming an annular shape, and a pair of tread portions disposed on both sides of the tread portion. a pair of sidewall portions, a pair of bead portions arranged radially inward of the pair of sidewall portions, a carcass layer mounted between the pair of bead portions, and each bead core of the pair of bead portions In the space formed by folding the carcass layer outward in the tire width direction at the position of , a bead filler disposed on the outer side of each bead core in the tire radial direction and a bead filler disposed on the outer peripheral side of the carcass layer in the tread portion an inner liner layer disposed on the inner surface of the tire along the carcass layer; and between the carcass layer and the inner liner layer, at a position radially inside the tire at the bead portion A pneumatic tire having a tie rubber layer disposed in a region excluding a certain tip, the bead of the tie rubber layer with respect to a perpendicular P drawn from the outermost end of the belt layer in the tire width direction toward the inner liner layer. The ratio L1/L2 of the protrusion amount L1 toward the side of the tire to the periphery length L2 along the tire inner surface from the intersection point A between the perpendicular line P and the tire inner surface to the tip point B of the bead toe is 0.25 or more and 0 0.90 or less, and the ratio Fh/SH of the height Fh from the tire seating position on the rim to the tire radial direction outer side of the bead filler with respect to the tire section height SH is 0.20 or more and 0.45 or less. The width in the tire width direction of the bead filler at a position intermediate the height Fh in the tire radial direction of the bead filler with respect to the width Fbw in the tire width direction at the innermost position in the tire radial direction of the bead filler. The Fmw ratio Fmw/Fbw is 0.4 or more and 0.8 or less, and the total gauge TGa, which is the sum of the thickness of the inner liner layer and the tie rubber layer, is 0.6 mm or more and 1.0 mm or less. There is .

The ratio D/SH of the distance D between the innermost end of the tie rubber layer in the tire radial direction and the outermost end of the bead filler in the tire radial direction to the tire section height SH is -0.2 or more. It is preferably 2 or less.

The inner liner layer with respect to the total thickness K1 of the sidewall portion at the tire maximum width position at a position 5 mm inward in the tire radial direction along the tire radial direction from the innermost end in the tire radial direction of the tie rubber layer. The ratio K2/K1 of the thickness K2 of the constituent butyl rubber is preferably 0.05 or more and 0.30 or less.

The hardness of the cap rubber used in the tread portion is preferably 60 or more and 75 or less.

Preferably, the belt layer includes a plurality of reinforcing cords inclined with respect to the tire circumferential direction, and the inclination angle of the reinforcing cords with respect to the tire circumferential direction is 24 degrees or more and 32 degrees or less.

The rubber compound used for the tread portion preferably contains 1 part by weight or more of an antioxidant.

ADVANTAGE OF THE INVENTION The pneumatic tire concerning this invention can implement|achieve weight reduction and steering-stability improvement, improving the durability in a high temperature area.

FIG. 1 is a cross-sectional view of a pneumatic tire according to an embodiment of the present invention taken along the tire meridian line. FIG. 2 is an enlarged view of a portion of FIG. 1; FIG. 3 is an enlarged view of a portion of FIG. 1; FIG. 4 is a cross-sectional view of a tire meridian direction showing a pneumatic tire according to a modification of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail based on the drawings. In the description of each embodiment below, the same reference numerals are given to components that are the same as or equivalent to those of other embodiments, and description thereof will be simplified or omitted. The present invention is not limited by each embodiment. In addition, the components of each embodiment include those that can be easily replaced by those skilled in the art, or those that are substantially the same. A plurality of modifications described in this embodiment can be arbitrarily combined within the scope obvious to those skilled in the art. Also, omissions, substitutions, or changes in configuration can be made without departing from the scope of the invention.

[Pneumatic tire]
FIG. 1 is a cross-sectional view of a pneumatic tire according to an embodiment of the present invention taken along the tire meridian line. FIG. 1 shows a cross-sectional view of one side region in the tire radial direction. Moreover, FIG. 1 shows a radial tire for a passenger car as an example of a pneumatic tire.

A cross section in the tire meridian direction is a cross section obtained by cutting the tire along a plane including the tire rotation axis (not shown). Further, the symbol CL is the tire equatorial plane, which is a plane perpendicular to the tire rotation axis passing through the center point of the tire in the tire rotation axis direction. The tire radial direction refers to a direction orthogonal to the rotation axis (not shown) of the pneumatic tire 100, the tire radial direction inner side is the side facing the rotation axis in the tire radial direction, and the tire radial direction outer side is the tire radial direction. The side away from the rotation axis in In addition, the tire circumferential direction refers to a circumferential direction around the rotation axis. Moreover, the tire width direction refers to a direction parallel to the rotation axis. The inner side in the tire width direction refers to the side toward the tire equatorial plane CL in the tire width direction, and the outer side in the tire width direction refers to the side away from the tire equatorial plane CL in the tire width direction. The tire equatorial plane CL is a plane perpendicular to the rotation axis of the pneumatic tire 100 and passing through the center of the tire width of the pneumatic tire 100 . The tire width is the width in the tire width direction between portions positioned on the outside in the tire width direction, that is, the distance between the portions furthest from the tire equatorial plane CL in the tire width direction. The tire equator line is a line that is on the tire equatorial plane CL and extends along the tire circumferential direction of the pneumatic tire 100 . In this embodiment, the tire equatorial line is given the same symbol "CL" as the tire equatorial plane.

As shown in FIG. 1, a pneumatic tire 100 of this embodiment includes a tread portion 1 extending in the tire circumferential direction and forming an annular shape, and a pair of sidewall portions 2, 2 arranged on both sides of the tread portion 1. and a pair of bead portions 3 , 3 arranged radially inward of the sidewall portions 2 .

A carcass layer 4 is mounted between the pair of bead portions 3,3. The carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction. The carcass layer 4 is folded back from the inner side to the outer side in the width direction of the tire around the bead core 5 arranged in each bead portion 3 . That is, the end portion of the carcass layer 4 extends from the tread portion 1 to the bead portion 3 via the sidewall portion 2 and is folded outward in the tire width direction at the bead portion 3 .

A bead filler 6 is arranged on the outer circumference of the bead core 5 of the bead portion 3 . The bead filler 6 is arranged outside each bead core 5 in the tire radial direction. The bead filler 6 is made of a rubber composition having a substantially triangular cross section. The bead filler 6 is arranged in a space formed by folding the carcass layer 4 outward in the tire width direction at the position of the bead core 5 . A rim cushion rubber (not shown) is arranged outside the bead filler 6 in the tire width direction. The rim cushion rubber constitutes the contact surface of the bead portion 3 against the rim flange (not shown).

A plurality of (two layers in the example of FIG. 1) belt layers 7 are embedded in the outer peripheral side of the carcass layer 4 in the tread portion 1 . Each belt layer 7 includes a plurality of reinforcing cords inclined with respect to the tire circumferential direction. A steel cord is preferably used as the reinforcing cord for the belt layer 7 .

At least one belt cover layer 8 formed by arranging reinforcing cords at an angle of, for example, 5 degrees or less with respect to the tire circumferential direction is arranged on the outer peripheral side of the belt layer 7 for the purpose of improving high-speed durability. there is Organic fiber cords such as nylon and aramid cords are preferably used as the reinforcing cords for the belt cover layer 8 .

An inner liner layer 9 is provided along the carcass layer 4 on the inner surface of the tire. The inner liner layer 9 is composed of a rubber composition mainly composed of butyl rubber having air permeation prevention performance, and prevents permeation of the air filled in the tire to the outside of the tire. The total gauge TGa, which is the sum of the thickness of the inner liner layer 9 and the thickness of the tie rubber layer 10, is preferably 0.6 mm or more and 1.3 mm or less. If the total gauge TGa is less than 0.6 mm, the effect of preventing air from permeating out of the tire is reduced, which is not preferable. If the total gauge TGa exceeds 1.3 mm, it is not preferable because it hinders weight reduction of the tire. More preferably, the total gauge TGa is 0.6 mm or more and 1.0 mm or less.

[Tie rubber layer]
A tie rubber layer 10 is arranged between the inner liner layer 9 and the carcass layer 4 . The tie rubber layer 10 is a layer for preventing the cords of the carcass layer 4 from digging into the inner liner layer 9 when an unvulcanized pneumatic tire is inflated during tire manufacture. The tie rubber layer 10 contributes to air permeation prevention properties and steering stability on dry road surfaces in the manufactured tire. In the pneumatic tire 100 of this example, the tie rubber layer 10 is selectively provided not on the entire area between the carcass layer 4 and the inner liner layer 9 but on the area excluding the tip side of the bead portion 3 . That is, as shown in FIG. 1 , the tie rubber layer 10 is provided on both sides of the tire equatorial plane CL in the tire width direction from the center region of the tread portion 1 to the region of the sidewall portion 2 via the shoulder region. In the pneumatic tire 100 of this example, the tie rubber layer 10 is not provided on the tip side of the bead portion 3, so when the tie rubber layer 10 is provided in the entire area between the carcass layer 4 and the inner liner layer 9 Lighter weight can be achieved compared to

In order to improve durability in high temperature regions, the butyl rubber of the inner liner layer 9 should be made relatively thick. Even in that case, by selectively providing the tie rubber layer 10 in the region excluding the tip side of the bead portion 3, compared to the case where the tie rubber layer 10 is provided in the entire area between the carcass layer 4 and the inner liner layer 9 , weight reduction can be achieved. If the butyl rubber of the inner liner layer 9 is made thinner, the weight can be reduced. However, reducing the thickness of the butyl rubber is not preferable because it leads to a decrease in air permeation prevention performance and a decrease in durability of the tire especially in high temperature regions.

[Arrangement area of tie rubber layer]
In FIG. 1, the amount of protrusion of the tie rubber layer 10 toward the bead portion 3 with respect to a perpendicular line P drawn from the outermost end of the belt layer 7 in the tire width direction toward the inner liner layer 9 is defined as L1. L2 is the periphery length along the tire inner surface from the intersection point A between the perpendicular line P and the tire inner surface to the tip point B of the bead toe. At this time, the ratio L1/L2 of the protrusion amount L1 to the length L2 is preferably 0.25 or more and 0.90 or less. If the ratio L1/L2 is less than 0.25, it becomes difficult to maintain air permeability, which is not preferable. If the ratio L1/L2 exceeds 0.90, the effect of reducing the tire weight is reduced, which is not preferable. The ratio L1/L2 is more preferably 0.30 or more and 0.70 or less.

[Belt layer]
Each belt layer 7 is arranged so that the reinforcing cords intersect each other between the layers. The inclination angle of the reinforcement cords of the belt layer 7 with respect to the tire circumferential direction is preferably 24 degrees or more and 32 degrees or less. If the inclination angle of the reinforcing cords with respect to the tire circumferential direction is 24 degrees or more and 32 degrees or less, steering stability performance is improved. Furthermore, the inclination angle of the reinforcing cords of the belt layer 7 with respect to the tire circumferential direction is more preferably in the range of 26 degrees or more and 28 degrees or less, and most preferably 27 degrees.

[Bead part]
FIG. 2 is an enlarged view showing the vicinity of the bead portion 3 of the pneumatic tire of FIG. In FIG. 2, Fh is the height from the seated position of the tire on the rim to the position of the bead filler 6 on the outer side in the tire radial direction. At this time, the ratio Fh/SH of the height Fh to the tire section height SH is preferably 0.20 or more and 0.45 or less. If the ratio Fh/SH is less than 0.20, the rigidity of the sidewall portion 2 is insufficient, and if the ratio Fh/SH exceeds 0.45, the rigidity of the sidewall portion 2 becomes too large. is also not preferable from the viewpoint of improving steering stability performance. In addition , it is preferable that the height Fh is, for example, 25 mm or more and 50 mm or less.

Here, the tire cross-sectional height SH is a distance of half the difference between the tire outer diameter and the rim diameter, and is measured in a non-loaded state with the tire mounted on a specified rim and given a specified internal pressure. The stipulated rim means the "applied rim" specified by JATMA, the "design rim" specified by TRA, or the "measuring rim" specified by ETRTO. In addition, the prescribed internal pressure means the "maximum air pressure" prescribed by JATMA, the maximum value of "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" prescribed by TRA, or "INFLATION PRESSURES" prescribed by ETRTO. In addition, the specified load means the "maximum load capacity" specified by JATMA, the maximum value of "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" specified by TRA, or the "LOAD CAPACITY" specified by ETRTO. However, according to JATMA, in the case of passenger car tires, the specified internal pressure is 180 [kPa] and the specified load is 88 [%] of the maximum load capacity.

In FIG. 2, the width of the bead filler 6 in the tire width direction at the innermost position in the tire radial direction is defined as Fbw. Further, Fmw is the width of the bead filler 6 in the tire width direction at an intermediate height between the height Fh from the seated position on the tire rim to the radially outer position of the bead filler 6 . At this time, the ratio Fmw/Fbw of the width Fmw to the width Fbw is preferably 0.4 or more and 0.8 or less. The fact that the ratio Fmw/Fbw is 0.4 or more and 0.8 or less means that the bead filler 6 has a cross-sectional shape that elongates outward in the tire radial direction. Since the bead filler 6 has such a cross-sectional shape, the rigidity of the sidewall portion 2 can be ensured, and the steering stability performance is improved. The ratio Fmw/Fbw is more preferably 0.55 or more and 0.78 or less. The ratio Fmw/Fbw is more preferably 0.65 or more and 0.75 or less.

The innermost end of the tie rubber layer 10 in the tire radial direction is designated as 10T1. The outermost end of the bead filler 6 in the tire radial direction is 6T. Let D be the distance along the tire radial direction between the end 10T1 and the end 6T. The ratio D/SH of the distance D to the tire section height SH is preferably -0.2 or more and 0.2 or less. The fact that the ratio D/SH is a negative value means that part of the tie rubber layer 10 and part of the bead filler 6 overlap when viewed in the tire width direction. A positive value of the ratio D/SH means that the position of the end 10T1 and the position of the end 6T are separated from each other when viewed in the tire width direction. The fact that the ratio D/SH is zero means that the position of the end 10T1 and the position of the end 6T match when viewed from the tire width direction.

If the ratio D/SH is less than -0.2, the weight of the tie rubber layer 10 is large, which is not preferable from the viewpoint of achieving weight reduction. If the ratio D/SH exceeds 0.2, the rigidity of the sidewall portion 2 is lowered, which is not preferable. The fact that the ratio D/SH is -0.2 or more and 0.2 or less means that the position of the end 10T1 and the position of the end 6T are very close and substantially the same. Since the position of the end 10T1 and the position of the end 6T are very close to each other, the rigidity of the sidewall portion 2 can be secured while reducing the weight, and the steering stability performance can be improved.

It should be noted that the distance D is preferably -20 mm or more and 20 mm or less, for example. A negative value for the distance D means that a portion of the tie rubber layer 10 and a portion of the bead filler 6 overlap when viewed in the tire width direction. A positive value of the distance D means that the position of the end 10T1 and the position of the end 6T are separated when viewed in the tire width direction. If the distance D is less than -20 mm, the weight of the tie rubber layer 10 is large, which is not preferable from the viewpoint of achieving weight reduction. If the distance D exceeds 20 mm, the rigidity of the sidewall portion 2 is lowered, which is not preferable.

[Sidewall part]
FIG. 3 is an enlarged view showing the vicinity of the sidewall portion 2 of the pneumatic tire of FIG. In FIG. 3, the total thickness of the sidewall portion 2 at the tire maximum width position C is defined as K1. Let K2 be the thickness of the butyl rubber forming the inner liner layer 9 at a position 5 mm radially inward along the tire radial direction from the radially innermost end 10T1 of the tie rubber layer 10 . At this time, the ratio K2/K1 of the thickness K2 of the butyl rubber to the total thickness K1 is preferably 0.05 or more and 0.30 or less.

[Tread rubber]
The rubber compound used for the tread portion 1 preferably contains 1 part by weight or more of an antioxidant. The pneumatic tire of this example can maintain durability performance in high-temperature regions by containing 1 part by weight or more of an anti-aging agent.

The hardness of the cap rubber used for the tread portion 1 is preferably 60 or more and 75 or less. If the hardness of the cap rubber is within this range, steering stability performance is improved. Further, the hardness of the tire cap rubber used for the tread portion 1 is more preferably 67 or more and 72 or less, and even more preferably 68 or more and 70 or less. The above hardness is JIS-A hardness, which is durometer hardness measured at a temperature of 20° C. using a type A durometer according to JIS K-6253.

[Modification]
The tire internal structure described above is a representative example of a pneumatic tire, but is not limited to this. FIG. 4 is a cross-sectional view in the tire meridian direction showing a modification of the pneumatic tire according to the embodiment of the present invention. In FIG. 4, the pneumatic tire of this example has butyl rubber arranged in the vicinity of the shoulder portion. In the pneumatic tire of this example, butyl rubber is not arranged in the center region of the tread portion 1 including the vicinity of the equatorial plane CL. Other parts of the pneumatic tire of this example are the same as those of the pneumatic tire described with reference to FIGS. In the pneumatic tire of this example, since butyl rubber is not arranged in the center region, it is possible to achieve further weight reduction.

Further, the pneumatic tire 100 may have a mounting direction indicator (not shown) that indicates the mounting direction with respect to the vehicle. The mounting direction display portion is configured by, for example, a mark or unevenness attached to the sidewall portion of the tire. For example, ECER30 (Economic Commission Regulations for Europe, Article 30) obliges the installation direction display portion to be provided on the side wall portion that is located outside in the vehicle width direction when the tire is installed in the vehicle.

The value of the ratio L1/L2 may be different between the inner side and the outer side with respect to the vehicle when mounted on the vehicle. Similarly, the value of the ratio Fh/SH may be different between the inner side and the outer side with respect to the vehicle when mounted on the vehicle. Similarly, the value of the above ratio Fmw/Fbw may differ between the inner side and the outer side with respect to the vehicle when mounted on the vehicle. Similarly, the value of the ratio D/SH may be different between the inner side and the outer side with respect to the vehicle when mounted on the vehicle. Similarly, the value of the ratio K2/K1 may be different between the inner side and the outer side with respect to the vehicle when mounted on the vehicle.

[Example]
Tables 1 to 5 are tables showing the results of performance tests of pneumatic tires according to the present invention. In this performance test, pneumatic tires different from each other, and in this example, a plurality of types of pneumatic tires under different conditions were evaluated with respect to durability performance, weight reduction, and steering stability performance (dry steering stability performance). . In these performance tests, a pneumatic tire (test tire) having a tire size of 185/60R15 84H (tire cross section height SH = 111 mm) was mounted on a regular rim of 15 x 6.0 J and filled with a regular internal pressure (240 kPa). .

Durability was evaluated by drum running tests in a constant temperature bath and indoors. After leaving the evaluation tire in a constant temperature bath at 80°C for one month, the running time until the tire breaks is measured under the condition that the load is equivalent to that of two passengers and the speed is 50 km/h. It was expressed as an index with the tire as the standard (100). The higher the index, the better the durability performance.

The weight reduction was evaluated by measuring the weight of a test tire mounted on a regular rim and expressing the weight as an index based on the weight of the pneumatic tire of Conventional Example 1 described later (100). The higher the index, the more weight reduction is achieved.

The steering stability performance was evaluated by mounting the test tire on a 1,500 cc FF (Front Engine Front Drive) compact car (test vehicle), running the test vehicle on a dry road test course, and measuring straightness and handling. was carried out by sensory evaluation by one experienced test driver. This sensory evaluation was expressed as an index based on the pneumatic tire of Conventional Example 1 (100). The higher the index, the better the steering stability performance.

In the pneumatic tires of Examples 1 to 38, the tie rubber layer is arranged between the carcass layer and the inner liner layer in a region excluding the tip of the bead portion, and the ratio L1/L2 is 0.25 or more. 0.90 or less, the ratio Fh/SH is 0.20 or more and 0.45 or less, and the ratio Fmw/Fbw is 0.4 or more and 0.8 or less.

In the pneumatic tire of Conventional Example 1, the tie rubber layer is provided over the entire area between the carcass layer and the inner liner layer, and does not contain an antioxidant. In the pneumatic tire of Conventional Example 2, the tie rubber layer is not provided in the center portion and the bead portion between the carcass layer and the inner liner layer, but is provided only in the shoulder portion, and does not contain an anti-aging agent.

These pneumatic tires were evaluated for durability performance, weight reduction, and steering stability performance by the evaluation methods described above, and the results are shown in Tables 1 to 5.

As shown in Tables 1 to 5, when the total gauge TGa, which is the sum of the thickness of the inner liner layer and the thickness of the tie rubber layer, is 0.6 mm or more and 1.3 mm or less, the ratio D/SH is -0. When it is 2 or more and 0.2 or less, the ratio K2/K1 is 0.05 or more and 0.30 at a position 5 mm inward in the tire radial direction from the innermost end of the tie rubber layer in the tire radial direction. In the following cases, when the hardness of the cap rubber used in the tread portion is 60 or more and 75 or less, and when the inclination angle of the reinforcement cord of the belt layer with respect to the tire circumferential direction is 24 degrees or more and 32 degrees or less, the tread portion Good results were obtained with respect to durability performance, weight reduction and steering stability performance when the rubber compound used contained 1 part by weight or more of an anti-aging agent.

1 tread portion 2 sidewall portion 3 bead portion 4 carcass layer 5 bead core 6 bead filler 6T end 7 belt layer 8 belt cover layer 9 inner liner layer 10 tie rubber layer 10T1 end CL tire equatorial plane

Claims (6)

A tread portion extending in the tire circumferential direction and forming an annular shape, a pair of sidewall portions arranged on both sides of the tread portion, and a pair of bead portions arranged radially inward of the pair of sidewall portions. and a carcass layer mounted between the pair of bead portions, and a space formed by folding the carcass layer outward in the tire width direction at the position of each bead core of the pair of bead portions, in each of the bead cores. A bead filler disposed radially outward of the tire, a belt layer disposed on the outer peripheral side of the carcass layer in the tread portion, an inner liner layer disposed on the inner surface of the tire along the carcass layer, and the carcass A pneumatic tire having a tie rubber layer disposed between the layer and the inner liner layer and in a region excluding the tip of the bead portion , which is located radially inward of the tire,
The protrusion amount L1 of the tie rubber layer toward the bead portion with respect to the perpendicular P drawn from the outermost end in the tire width direction of the belt layer toward the inner liner layer, between the perpendicular P and the inner surface of the tire. A ratio L1/L2 to a peripheral length L2 along the tire inner surface from the intersection point A to the tip point B of the bead toe is 0.25 or more and 0.90 or less,
The ratio Fh/SH of the height Fh from the seating position on the rim of the tire to the tire radial direction outer side of the bead filler to the tire cross-sectional height SH is 0.20 or more and 0.45 or less,
The width Fmw in the tire width direction of the bead filler at a position intermediate the height Fh of the bead filler in the tire radial direction with respect to the width Fbw in the tire width direction at the innermost position in the tire radial direction of the bead filler The ratio Fmw/Fbw is 0.4 or more and 0.8 or less,
A pneumatic tire, wherein a total gauge TGa, which is the sum of the thickness of the inner liner layer and the thickness of the tie rubber layer, is 0.6 mm or more and 1.0 mm or less. The ratio D/SH of the distance D between the innermost end of the tie rubber layer in the tire radial direction and the outermost end of the bead filler in the tire radial direction to the tire section height SH is -0.2 or more. 2 or less, the pneumatic tire according to claim 1 . The inner liner layer with respect to the total thickness K1 of the sidewall portion at the tire maximum width position at a position 5 mm inward in the tire radial direction along the tire radial direction from the innermost end in the tire radial direction of the tie rubber layer. 3. The pneumatic tire according to claim 1, wherein the ratio K2/K1 of the thickness K2 of the constituent butyl rubber is 0.05 or more and 0.30 or less. The pneumatic tire according to any one of claims 1 to 3 , wherein the hardness of the cap rubber used in the tread portion is 60 or more and 75 or less. 5. The belt layer according to any one of claims 1 to 4 , wherein the belt layer includes a plurality of reinforcing cords inclined with respect to the tire circumferential direction, and the inclination angle of the reinforcing cords with respect to the tire circumferential direction is 24 degrees or more and 32 degrees or less. 1. A pneumatic tire according to 1. The pneumatic tire according to any one of claims 1 to 5 , wherein the rubber compound used for the tread portion contains 1 part by weight or more of an antioxidant.

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