pneumatic tires

Abstract

To improve durability performance of a bead part.SOLUTION: A pneumatic tire 1 is given in which a first apex rubber 8 is arranged at a bead part 4. The first apex rubber 8 extends from an outer face 5a of a bead core 5 in a tire radial direction to an outer side in the tire radial direction. An outer end 8e of the first apex rubber 8 in the tire radial direction is not positioned within a first region 10 when the pneumatic tire 1 is attached to the rim R and filled with predetermined inner pressure. The first region 10 is formed between a first tire radial direction line n1 passing through an outer end 11e of a contact area 11 in the tire radial direction where a rim flange Rf of the rim R contacts with the bead part 4 and a second tire radial direction line n2 passing through a separated position which is separated by 10 mm from the outer end 11e of the contact area 11 to an outer side in a tire axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to pneumatic tires. [Background technology]

[0002] Patent Document 1 listed below describes a pneumatic tire for small shuttle buses with a total vehicle weight exceeding 3 tons. This type of pneumatic tire has a small diameter to ensure a large passenger space. Furthermore, the pneumatic tire of Patent Document 1 has an increased load-bearing capacity due to the circumferential groove arrangement, the ratio of the tire outer diameter to the rim diameter, and other factors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 122240 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned pneumatic tires have a small diameter, which reduces the air volume required to support the vehicle weight and also reduces the tire cross-sectional height, which causes strain to concentrate in the bead portion during high-load driving, which in turn causes damage that originates from the bead portion.

[0005] The present disclosure has been devised in view of the above circumstances, and has as its main object to improve the durability of the bead portion in a pneumatic tire mounted on a rim having a rim diameter of 12 to 17 inches. [Means for solving the problem]

[0006] The present disclosure relates to a pneumatic tire mounted on a rim having a rim diameter of 12 to 17 inches, wherein the ratio (SH / SW) of the tire section height SH to the tire section width SW is 0.30 to 0.45, the ratio (RW / SW) of the rim width RW to the tire section width SW of the rim is 0.78 to 0.99, and the tire has a pair of bead portions each having a bead core embedded therein, and at least one of the pair of bead portions has a first apex extending from the outer surface of the bead core in the tire radial direction to the outside in the tire radial direction. When the pneumatic tire is mounted on the rim and inflated to a specified internal pressure, the radially outer end of the first apex rubber is not located inside the first region, where a first tire radial line passes through the radially outer end of the contact area where the rim flange of the rim and the bead portion contact the ground, and a second tire radial line passes through a position 10 mm axially outward from the outer end of the contact area. [Effects of the Invention]

[0007] By employing the above-described configuration, the pneumatic tire of the present disclosure can improve the durability performance of the bead portion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a tire meridian cross-sectional view of a pneumatic tire according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a bead portion in FIG. [Figure 3] FIG. 2 is an enlarged view of a bead portion in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a tire meridian cross-sectional view including the tire rotation axis (not shown) of a pneumatic tire (hereinafter sometimes simply referred to as "tire") 1 of this embodiment. The tire 1 of the present disclosure is used, for example, in a new small shuttle bus that is primarily intended for transporting people and goods within cities. This type of bus requires a large passenger space, and some have a total vehicle weight exceeding 3 tons. The bus may also be an electric vehicle with an autonomous driving function and an in-wheel motor (not shown). The tire 1 of the present disclosure may also be used as a tire 1 for passenger cars or heavy loads.

[0010] FIG. 1 shows tire 1 mounted on rim R and inflated to a specified internal pressure. The "specified internal pressure" refers to the internal pressure at which tire 1 performs optimally, for example, 400 to 1100 kPa or 500 to 900 kPa. When tire 1 is for passenger cars or heavy loads, the "specified internal pressure" refers to the air pressure specified for each tire by the respective standards in the standard system that includes the standard on which tire 1 is based. For example, JATMA uses "maximum air pressure," TRA uses the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES," and ETRTO uses "INFLATION PRESSURE." Unless otherwise specified, the dimensions of each part of tire 1 are values ​​measured when inflated to the specified internal pressure and in an unloaded state.

[0011] The "rim R" adopted is one that is compatible with the tire 1. When the tire 1 is for a passenger car or a heavy load, the "rim R" is the rim determined for each tire by the standard system that includes the standard on which the tire is based, such as a "standard rim" for JATMA, a "design rim" for TRA, or a "measuring rim" for ETRTO.

[0012] The tire 1 is mounted on a rim R having a rim diameter RD of 12 to 17 inches. In this way, the tire 1 of the present disclosure is one having a small diameter.

[0013] The tire 1 has a ratio (SH / SW) of the tire section height SH to the tire section width SW of 0.30 to 0.45. The tire 1 also has a ratio (RW / SW) of the rim width RW of the rim R to the tire section width SW of 0.78 to 0.99. As such, the tire 1 of the present disclosure has a low aspect ratio and ensures an air volume sufficient to support the vehicle weight. Suitable sizes for such a tire 1 are, for example, 205 / 40R15 or 215 / 45R12. The rim width of the rim R that is compatible with the tire 1 of these sizes is 7.0J or 7.5J. The tire 1 of the present disclosure preferably has a large storage space within the rim R to accommodate the in-wheel motor.

[0014] The rim diameter RD is the outer diameter of the rim body portion Rh of the rim R and does not include the rim flange Rf. The tire section width SW is the maximum axial width of the tire 1 excluding the rim guard (not shown). The tire section height SH is the radial distance between the rim diameter position (not shown) that determines the rim diameter RD and the radially outermost end of the tire 1 (obtained by filling in a groove if one is provided at the tire equator). In addition, when the tire 1 is for passenger cars or heavy load vehicles, the axial line passing through the rim diameter position is called the bead baseline. The rim width RW is the axial distance between the axially inner ends of the rim flanges Rf on both sides. When the tire 1 is for passenger cars or heavy load vehicles, the rim diameter RD and rim width RW are determined in accordance with the JATMA standard on which the rim R is based.

[0015] The tire 1 includes a pair of bead portions 4, 4 each having a bead core 5 embedded therein. A first apex rubber 8 is disposed in at least one of the pair of bead portions 4, extending radially outward from the radially outer surface 5a of the bead core 5. In this embodiment, the first apex rubber 8 is disposed in each of the pair of bead portions 4. Due to its structure, strain is likely to concentrate at the radially outer end 8e of the first apex rubber 8.

[0016] FIG. 2 is an enlarged view of the bead portion 4 in FIG. 1. As shown in FIG. 2, in the present disclosure, a first region 10 is defined in the bead portion 4. The first region 10 is formed between a first tire radial line n1 and a second tire radial line n2. The first tire radial line n1 is a straight line extending in the tire radial direction through the tire radial outer end 11e of the contact patch 11 where the rim flange Rf of the rim R and the bead portion 4 come into contact with the tire. The second tire radial line n2 is a straight line extending in the tire radial direction through a separation position 12 that is 10 mm axially outward from the outer end 11e of the contact patch 11. This first region 10 is a region where large strain concentrates during high-load running. In this embodiment, the outer end 11e of the contact patch 11 is located radially inward of the tire radial outer end 5j of the bead core 5.

[0017] In the present disclosure, the outer end 8e of the first apex rubber 8 is not located inside the first region 10. Therefore, damage originating from the outer end 8e is suppressed, and the durability of the bead portion 4 is improved.

[0018] 1, in this embodiment, the tire 1 includes a carcass 6 extending between the bead cores 5, 5. The tire 1 also includes a belt layer 7, a second apex rubber 9, a sidewall rubber 3G, a clinch rubber 4G, and a chafer 13.

[0019] The carcass 6 includes a carcass ply 6A including a main body portion 6a extending between the bead cores 5, 5 and a pair of turned-up portions 6b folded back around each bead core 5 from the inner side in the tire axial direction to the outer side and extending radially outward in the tire. In this embodiment, the carcass 6 is formed of two carcass plies 6A, 6B arranged radially inside and outside the tire. Each carcass ply 6A, 6B includes a main body portion 6a and a pair of turned-up portions 6b, and is formed in a well-known structure in which carcass cords (not shown) are covered with a rubber material. In this embodiment, the radially outer end 6e of each turned-up portion 6b extends radially outward beyond the outer end 8e of the first apex rubber 8. Note that the carcass 6 may be formed of, for example, a single carcass ply 6A (not shown).

[0020] In this embodiment, the belt layer 7 is composed of an inner belt ply 7a and an outer belt ply 7b disposed radially outward of the inner belt ply 7a. An outer end 7h of the inner belt ply 7a is positioned axially outward of an outer end 7k of the outer belt ply 7b. Each of the belt plies 7a, 7b includes a belt cord (not shown) made of, for example, a steel cord, and has the same configuration as a belt layer in a typical truck or bus tire.

[0021] 2, the first apex rubber 8 is disposed between the main body portion 6a and the turned-up portion 6b of the outer carcass ply 6B. In other words, the first apex rubber 8 comes into contact with the main body portion 6a and the turned-up portion 6b of the outer carcass ply 6B.

[0022] In this embodiment, the outer end 8e of the first apex rubber 8 is located axially inward of the first region 10. In other words, the first apex rubber 8 is not disposed within the first region 10. As a result, an interface between the first apex rubber 8 and the carcass ply 6B is not formed in the first region 10, and damage caused by peeling between them does not occur, further improving the durability of the bead portion 4. In the case where the outer end 8e of the first apex rubber 8 is located axially outward of the first region 10, the interface is formed, but damage originating from the outer end 8e is suppressed, thereby improving the durability of the bead portion 4.

[0023] The distance La in the tire axial direction between the outer end 8e of the first apex rubber 8 and the outer end 11e of the contact patch 11 is preferably 2 mm or less. If the outer end 8e of the first apex rubber 8 is spaced more than 2 mm axially inward from the outer end 11e of the contact patch 11, it may not be possible to increase the rigidity near the outer end 11e where particularly large strain occurs, and this may prevent improvement in durability.

[0024] The complex modulus E* of such first apex rubber 8 is, for example, preferably 25 MPa or more, more preferably 30 MPa or more, and preferably 40 MPa or less, and even more preferably 35 MPa or less. The complex modulus E* is measured for each test vulcanized rubber sheet in accordance with the provisions of "JIS K 6394" using a spectrometer manufactured by Ueshima Seisakusho Co., Ltd. under the conditions of a dynamic strain amplitude of 1%, a frequency of 10 Hz, and a temperature of 70°C.

[0025] The first apex rubber 8 includes an outer portion 8A located axially outward of the axially outer end 5e of the bead core 5. In a tire meridian cross section, the ratio (So / S) of the cross-sectional area S of the first apex rubber 8 to the cross-sectional area So of the outer portion 8A is preferably 0.2 or greater. A ratio (So / S) of 0.2 or greater maintains the rigidity of the portion axially outward of the bead core 5, thereby suppressing distortion due to running and improving durability. To enhance this effect, the ratio (So / S) is more preferably 0.25 or greater. If the ratio (So / S) is too large, a large load due to running may act on the radially inner portion of the first apex rubber 8, potentially reducing durability. Therefore, the ratio (So / S) is preferably 0.35 or less, and more preferably 0.30 or less.

[0026] 1, the height HA of the first apex rubber 8 in the tire radial direction is preferably 175% or more, more preferably 200% or more, and more preferably 275% or less, and even more preferably 250% or less of the height HC of the bead core 5 in the tire radial direction. This allows the above-mentioned effects to be effectively exhibited.

[0027] For example, the outer end 8e of the first apex rubber 8 is located more inward in the tire axial direction than the outer end 7h of the inner belt ply 7a. In this embodiment, the outer end 8e of the first apex rubber 8 is located more outward in the tire axial direction than the outer end 7k of the outer belt ply 7b.

[0028] In this embodiment, the second apex rubber 9 is disposed axially outward of the pair of turned-up portions 6b and is adjacent to the turned-up portion 6b of the inner carcass ply 6A on the axially outer side thereof.

[0029] In this embodiment, the second apex rubber 9 has the same complex modulus of elasticity E* as the first apex rubber 8. This reduces the difference in strain between the first apex rubber 8 and the first apex rubber 9, making it difficult for strain to occur in the entire bead portion, thereby improving durability.

[0030] Fig. 3 is an enlarged view of the bead portion 4. As shown in Fig. 3, the second apex rubber 9 is formed in a sheet shape with a thickness d that is, for example, 40% or less of the maximum axial width Wa of the first apex rubber 8. Such a second apex rubber 9 maintains the width of the bead portion 4 small to ensure deformation (deflection) during running and distributes the load, thereby improving durability.

[0031] The inner end 9i of the second apex rubber 9 in the tire radial direction is located more inward in the tire radial direction than a position P1 that is 2 mm outwardly in the tire radial direction from the outer end 5j of the bead core 5 in the tire radial direction. This reduces the rigidity difference in the vicinity of the bead core 5, further improving the durability of the bead portion 4. In this embodiment, the inner end 9i of the second apex rubber 9 is located more outward in the tire radial direction than the outer end 5j of the bead core 5. Furthermore, the inner end 9i of the second apex rubber 9 is located more outward in the tire radial direction than the outer end 11e of the contact patch 11.

[0032] The radially outer end 9e of the second apex rubber 9 is located at a position axially outwardly spaced from the first region 10 by 10 mm or more. This reinforces the rigidity of the bead portion 4, further improving durability. The axial length Lb between the radially outer end 9e of the second apex rubber 9 and the first region 10 (spaced position 12 (shown in FIG. 2)) is preferably 160% or more of the maximum width Wa of the first apex rubber 8, more preferably 180% or more, more preferably 240% or less, and even more preferably 220% or less. The radially outer end 9e of the second apex rubber 9 is located, for example, radially outwardly of the radially outer end 4e of the clinch rubber 4G.

[0033] The distance L1 in the tire radial direction between the outer end 9e of the second apex rubber 9 and the outer end 8e of the first apex rubber 8 is preferably 50% or more, more preferably 55% or more, and more preferably 70% or less, and even more preferably 65% ​​or less of the height HB of the second apex rubber 9 in the tire radial direction. The height HB of the second apex rubber 9 is preferably 200% or more, more preferably 20% or more, and more preferably 280% or less, and even more preferably 260% or less of the height HA (shown in FIG. 1) of the first apex rubber 8 in the tire radial direction. This allows the above-mentioned effects to be effectively exhibited.

[0034] The sidewall rubber 3G and the clinch rubber 4G of this embodiment are formed from various well-known constituent materials. The clinch rubber 4G is adjacent to the sidewall rubber 3G on the radially inner side of the tire. In this embodiment, the clinch rubber 4G includes a portion that comes into contact with the rim. The radially inner end 4i of the clinch rubber 4G is located radially inward of the radially inner end 5i of the bead core 5 (shown in FIG. 2).

[0035] The chafer 13 of this embodiment is formed in a U-shape including a first portion 13a, a second portion 13b, and a third portion 13c. The third portion 13c, for example, contacts the rim R and is located radially inward of the inner end 5i of the bead core 5. The first portion 13a of this embodiment extends radially outward from the axially inner end of the third portion 13c to form the inner cavity of the tire 1. In this embodiment, the second portion 13b extends radially outward from the axially outer end of the third portion 13c. The second portion 13b extends, for example, between the turned-up portion 6b of the inner carcass ply 6A and the second apex rubber 9.

[0036] Although one embodiment of the present disclosure has been described in detail above, the present disclosure is not limited to the above specific embodiment and can be modified and implemented in various aspects. [Example]

[0037] Pneumatic tires having the basic structure shown in Figure 1 were prototyped based on the specifications in Table 1. The durability performance of the bead portion of each test tire was then tested. The common specifications and test methods for each test tire are as follows:

[0038] <Durability> Each test tire was run under the following conditions, and the running distance until damage to the bead portion was measured. The test results were expressed as an index, with the result of Example 1 being 100. A score of 95 or higher was considered a pass. Tire size: 205 / 40R15 Rim: 7.0J Internal pressure: 520kPa Ratio (SH / SW):0.40 Ratio (RW / SW):0.87 Vehicle: Toyota Motor Corporation's E-Pallet The test results are shown in Table 1. In Table 1, "-" for La means that the outer end of the first apex rubber is located axially outside the outer end of the contact patch. *1 means that the radially inner end of the second apex rubber is located 5 mm radially outward from the radially outer end of the bead core. *2 means that the radially outer edge of the second apex rubber is located 5 mm axially outward from the outer edge of the contact area.

[0039] [Table 1]

[0040] As a result of the test, it is understood that the tires of the examples have improved durability performance in the bead portions compared to the tires of the comparative examples.

[0041] [Note] The present disclosure includes the following aspects.

[0042] [Disclosure 1] A pneumatic tire mounted on a rim with a rim diameter of 12 to 17 inches, The ratio (SH / SW) of the tire section height SH to the tire section width SW is 0.30 to 0.45, The ratio (RW / SW) of the rim width RW to the tire section width SW is 0.78 to 0.99, The tire has a pair of bead portions each having a bead core embedded therein, a first apex rubber extending from an outer surface of the bead core in the tire radial direction to an outer side in the tire radial direction is disposed in at least one of the pair of bead portions; When the pneumatic tire is mounted on the rim and inflated to a specified internal pressure, the first region is defined as a region between a first tire radial line passing through the outer edge in the tire radial direction of a contact area where the rim flange of the rim and the bead portion contact the ground, and a second tire radial line passing through a position spaced 10 mm outward in the tire axial direction from the outer edge of the contact area, an outer end of the first apex rubber in the tire radial direction is not located inside the first region; Pneumatic tires. [Disclosure 2] The pneumatic tire according to Disclosure 1, wherein the outer end of the first apex rubber is positioned axially inward of the first region. [Disclosure 3] The pneumatic tire according to Disclosure 1, wherein the distance in the tire axial direction between the outer end of the first apex rubber and the outer end of the contact area is 2 mm or less. [Disclosure 4] the first apex rubber includes an outer portion located axially outward of an axially outer end of the bead core, The pneumatic tire according to any one of Disclosures 1 to 3, wherein in a tire meridian cross section, the ratio (So / S) of the cross-sectional area S of the first apex rubber to the cross-sectional area So of the outer portion is 0.2 or more. [Disclosure 5] a carcass extending between the bead cores; the carcass includes a carcass ply including a main body portion extending between the bead cores and a pair of turn-up portions turned around each of the bead cores from the inside to the outside in the tire axial direction and extending outward in the tire radial direction, The pneumatic tire according to any one of Disclosures 1 to 4, wherein a second apex rubber is disposed on the outer sides of the pair of turned-up portions in the tire axial direction. [Disclosure 6] The pneumatic tire according to Disclosure 5, wherein the second apex rubber is in a sheet shape with a thickness of 40% or less of the maximum width of the first apex rubber in the tire axial direction. [Disclosure 7] A pneumatic tire as described in Disclosure 5 or 6, wherein the radially inner end of the second apex rubber is located radially inward of a position 2 mm away from the radially outer end of the bead core. [Disclosure 8] The pneumatic tire according to any one of Disclosures 5 to 7, wherein the outer end of the second apex rubber in the tire radial direction is disposed at a position spaced 10 mm or more outward from the first region in the tire axial direction. [Explanation of symbols]

[0043] 1 pneumatic tire 4 Bead section 5 bead core 5a Exterior 8. First Apex Rubber 8e outer edge R rim Rf rim flange 10 First area 11 Grounding area 11e Outer edge n1 First tire radial line n2 Second tire radial line

Claims

1. A pneumatic tire mounted on a rim with a rim diameter of 12 to 17 inches, The ratio (SH / SW) of the tire section height SH to the tire section width SW is 0.30 to 0.45, a ratio (RW / SW) of a rim width RW of the rim to a tire section width SW is 0.78 to 0.99, The tire has a pair of bead portions each having a bead core embedded therein, a first apex rubber extending from an outer surface of the bead core in the tire radial direction to an outer side in the tire radial direction is disposed in at least one of the pair of bead portions; When the pneumatic tire is mounted on the rim and inflated to a specified internal pressure, the first region is defined as a region between a first tire radial line passing through the outer edge in the tire radial direction of a contact area where the rim flange of the rim and the bead portion contact the ground, and a second tire radial line passing through a position spaced 10 mm outward in the tire axial direction from the outer edge of the contact area, an outer end of the first apex rubber in the tire radial direction is not located inside the first region, a distance in the tire axial direction between the outer end of the first apex rubber and the outer end of the contact area is 2 mm or less; Pneumatic tires.

2. A pneumatic tire mounted on a rim with a rim diameter of 12 to 17 inches, The ratio (SH / SW) of the tire section height SH to the tire section width SW is 0.30 to 0.45, a ratio (RW / SW) of a rim width RW of the rim to a tire section width SW is 0.78 to 0.99, The tire has a pair of bead portions each having a bead core embedded therein, a first apex rubber extending from an outer surface of the bead core in the tire radial direction to an outer side in the tire radial direction is disposed in at least one of the pair of bead portions; When the pneumatic tire is mounted on the rim and inflated to a specified internal pressure, the first region is defined as a region between a first tire radial line passing through the outer edge in the tire radial direction of a contact area where the rim flange of the rim and the bead portion contact the ground, and a second tire radial line passing through a position spaced 10 mm outward in the tire axial direction from the outer edge of the contact area, an outer end of the first apex rubber in the tire radial direction is not located inside the first region, the first apex rubber includes an outer portion located axially outward of an axially outer end of the bead core, In a tire meridian cross section, a ratio (So / S) of a cross-sectional area S of the first apex rubber to a cross-sectional area So of the outer portion is 0.2 or more. Pneumatic tires.

3. A pneumatic tire mounted on a rim with a rim diameter of 12 to 17 inches, The ratio (SH / SW) of the tire section height SH to the tire section width SW is 0.30 to 0.45, a ratio (RW / SW) of a rim width RW of the rim to a tire section width SW is 0.78 to 0.99, The tire has a pair of bead portions each having a bead core embedded therein, a first apex rubber extending from an outer surface of the bead core in the tire radial direction to an outer side in the tire radial direction is disposed in at least one of the pair of bead portions; When the pneumatic tire is mounted on the rim and inflated to a specified internal pressure, the first region is defined as a region between a first tire radial line passing through the outer edge in the tire radial direction of a contact area where the rim flange of the rim and the bead portion contact the ground, and a second tire radial line passing through a position spaced 10 mm outward in the tire axial direction from the outer edge of the contact area, an outer end of the first apex rubber in the tire radial direction is not located inside the first region, a carcass extending between the bead cores; the carcass includes a carcass ply including a main body portion extending between the bead cores and a pair of turn-up portions turned around each bead core from the inside to the outside in the tire axial direction and extending outward in the tire radial direction, a second apex rubber is disposed on the outer side of the pair of folded-back portions in the tire axial direction, the second apex rubber is in a sheet shape with a thickness of 40% or less of the maximum width of the first apex rubber in the tire axial direction; Pneumatic tires.

4. A pneumatic tire mounted on a rim with a rim diameter of 12 to 17 inches, The ratio (SH / SW) of the tire section height SH to the tire section width SW is 0.30 to 0.45, a ratio (RW / SW) of a rim width RW of the rim to a tire section width SW is 0.78 to 0.99, The tire has a pair of bead portions each having a bead core embedded therein, a first apex rubber extending from an outer surface of the bead core in the tire radial direction to an outer side in the tire radial direction is disposed in at least one of the pair of bead portions; When the pneumatic tire is mounted on the rim and inflated to a specified internal pressure, the first region is defined as a region between a first tire radial line passing through the outer edge in the tire radial direction of a contact area where the rim flange of the rim and the bead portion contact the ground, and a second tire radial line passing through a position spaced 10 mm outward in the tire axial direction from the outer edge of the contact area, an outer end of the first apex rubber in the tire radial direction is not located inside the first region, a carcass extending between the bead cores; the carcass includes a carcass ply including a main body portion extending between the bead cores and a pair of turn-up portions turned around each bead core from the inside to the outside in the tire axial direction and extending outward in the tire radial direction, a second apex rubber is disposed on the outer side of the pair of folded-back portions in the tire axial direction, an inner end of the second apex rubber in the tire radial direction is located radially inward of a position spaced 2 mm radially outward from an outer end of the bead core in the tire radial direction; Pneumatic tires.

5. A pneumatic tire mounted on a rim with a rim diameter of 12 to 17 inches, The ratio (SH / SW) of the tire section height SH to the tire section width SW is 0.30 to 0.45, a ratio (RW / SW) of a rim width RW of the rim to a tire section width SW is 0.78 to 0.99, The tire has a pair of bead portions each having a bead core embedded therein, a first apex rubber extending from an outer surface of the bead core in the tire radial direction to an outer side in the tire radial direction is disposed in at least one of the pair of bead portions; When the pneumatic tire is mounted on the rim and inflated to a specified internal pressure, the first region is defined as a region between a first tire radial line passing through the outer edge in the tire radial direction of a contact area where the rim flange of the rim and the bead portion contact the ground, and a second tire radial line passing through a position spaced 10 mm outward in the tire axial direction from the outer edge of the contact area, an outer end of the first apex rubber in the tire radial direction is not located inside the first region, a carcass extending between the bead cores; the carcass includes a carcass ply including a main body portion extending between the bead cores and a pair of turn-up portions turned around each bead core from the inside to the outside in the tire axial direction and extending outward in the tire radial direction, a second apex rubber is disposed on the outer side of the pair of folded-back portions in the tire axial direction, an outer end of the second apex rubber in the tire radial direction is disposed at a position spaced 10 mm or more outward from the first region in the tire axial direction; Pneumatic tires.

6. A pneumatic tire described in any one of claims 1 to 5, wherein the outer end of the first apex rubber is located axially inward of the first region.

7. A tire including a carcass extending between the bead cores, the carcass includes a carcass ply including a main body portion extending between the bead cores and a pair of turn-up portions turned around each bead core from the inside to the outside in the tire axial direction and extending outward in the tire radial direction, The pneumatic tire according to claim 1 or 2, wherein a second apex rubber is disposed axially outward of the pair of turned-up portions.

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