JP2012236499A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of improving both lateral grip performance and traction performance in a high level.SOLUTION: An asymmetric tread pattern includes an inner lateral groove in which an angle θi relative to a tire axis direction is small in a tread half part inside the vehicle, and an outer lateral groove in which an angle θo relative to the tire axis direction is large in a tread half part outside the vehicle. Folding height inside the vehicle of a second carcass ply 6b is smaller than the folding height outside the vehicle. An apex height of bead apex rubber 8i inside the vehicle is smaller than an apex height of bead apex rubber 8o outside the vehicle. A radial distance from a tread end TE to an outer end of a cutting protector 11o outside the vehicle is a smaller than the radial distance from the tread end TE to the outer end of a cutting protector 11i inside the vehicle.

Description

  The present invention relates to a pneumatic tire that is suitable as a rally tire or the like and has improved both grip performance and traction performance during cornering in rough terrain traveling.

  For rough terrain tires used for rough terrain driving, the traction performance for gripping the road surface firmly and transmitting the driving force to the road surface is suppressed, and the skidding of the tire during cornering is suppressed. Grip performance (lateral grip performance) is required.

  Therefore, various proposals have been made regarding tread patterns. For example, Patent Documents 1 and 2 below propose asymmetric tread patterns in which patterns are different on both sides of the tire equator. In this pattern, in the tread half inside the vehicle, which has a large contribution to traction performance, a horizontally long block is formed that is divided by lateral grooves with a small angle to the tire axial direction. Conversely, grip performance (lateral grip performance) In the tread half part on the vehicle outer side that greatly contributes to the vehicle, a longitudinal block is formed that is divided by an outer lateral groove having a large angle with respect to the tire axial direction.

  On the other hand, in the tire for running on rough terrain, in order to further improve the grip performance (lateral grip performance) during cornering on a hard road surface, it is required to increase the side rigidity of the tire. For this reason, for example, a bead apex is required. Increasing the radial height (apex height) of the rubber and increasing the radial height (folded height) of the folded portion of the carcass ply is performed.

  However, when the side rigidity of the tire is increased, the deformation of the tire is reduced on an uneven terrain surface with many irregularities, and therefore, the ground contact area is reduced particularly at a low load. Further, since the spring constant of the tire increases due to the increase in the side rigidity, the spring of the tire increases and the contact time is reduced. The reduction in the contact area and the contact time results in a decrease in traction performance, and there is a problem that even when the asymmetric pattern is employed in order to improve the traction performance, the effect is not sufficiently exhibited.

Japanese Patent Laid-Open No. 11-268506 JP 2001-180230 A

  Therefore, the present invention is based on reducing the apex height of the bead apex rubber and the folding height of the carcass ply on the inner side of the vehicle as compared with the apex height of the bead apex rubber and the folding height of the carcass ply on the outer side of the vehicle. The object of the present invention is to provide a pneumatic tire that can sufficiently exhibit the effect of an asymmetric pattern and can improve the grip performance (lateral grip performance) and traction performance at the time of cornering on rough terrain. .

In order to solve the above-mentioned problem, the invention of claim 1 of the present application is directed to a main body part extending from the tread part through the sidewall part to the bead core of the bead part, and the circumference of the bead core from both ends of the main body part on the inner side in the tire axial direction. A carcass having a folded portion folded back to the outside,
A bead apex rubber that extends from the bead core to the outside in the radial direction through the space between the body portion and the folded portion;
And a pneumatic tire provided with a rib-shaped cut protector that is arranged in an upper sidewall region extending from the tire maximum width position to the tread edge, and that rises from the sidewall outer surface and continuously extends in the tire circumferential direction,
The tread portion has an asymmetric tread pattern with different patterns on both sides of the tire equatorial plane, and the inner half of the tread half that is inside the vehicle from the tire equatorial plane when the vehicle is mounted extends from the tread edge toward the tire equatorial plane. The lateral grooves of the outer side of the vehicle and the outer half of the tread on the outer side of the vehicle are respectively provided with outer lateral grooves extending from the tread end toward the tire equatorial plane in the circumferential direction, and the angle θi of the inner lateral groove with respect to the tire axial direction It is smaller than the angle θo of the outer lateral groove with respect to the tire axial direction,
The carcass is composed of a plurality of carcass plies including a first carcass ply arranged closest to the tire lumen side and a second carcass ply placed on the outside thereof,
Moreover, the folding height in the radial direction from the bead base line of the folded portion of the second carcass ply is such that the folded height of the folded portion on the vehicle inner side is smaller than the folded height of the folded portion on the vehicle outer side, and In other carcass plies, the folding height of the folding part inside the vehicle is the same as the folding height of the folding part outside the vehicle,
The apex height in the radial direction from the bead base line of the bead apex rubber is such that the apex height of the bead apex rubber inside the vehicle is smaller than the apex height of the bead apex rubber outside the vehicle,
The radial distance from the tread end at the radially outer end of the cut protector is characterized in that the radial distance of the cut protector outside the vehicle is smaller than the radial distance of the cut protector inside the vehicle.

In the invention of claim 2, the asymmetric tread pattern is a block pattern,
The tread half portion on the vehicle inner side includes a row of horizontally long blocks in which a horizontally long block whose block length on the tire axial direction side is larger than the block length on the circumferential side is arranged in the circumferential direction,
The tread half portion outside the vehicle includes a row of vertically long blocks in which a longitudinal block whose block length on the tire axial direction side is smaller than a block length on the circumferential side is arranged in the circumferential direction, and does not include a row of horizontally long blocks. It is characterized by.

  According to a third aspect of the invention, an aramid reinforcing layer in which aramid fiber cords are arranged is arranged on the sidewall portion outside the vehicle, and an aramid reinforcing layer is not arranged on the sidewall portion inside the vehicle. Yes.

  In this specification, unless otherwise specified, the dimensions and the like of each part of the tire are values specified when the bead part is held in accordance with the rim width defined by the tire size in a non-rim assembled state. .

  As described above, the present invention employs an asymmetric pattern in which the angle θi of the inner lateral groove with respect to the tire axial direction is smaller than the angle θo of the outer lateral groove, while the apex height of the bead apex rubber and the carcass inside the vehicle The folding height of the ply is set to be smaller than the apex height and the folding height on the outside of the vehicle to reduce the side rigidity on the inside of the vehicle.

  As described above, the side rigidity is reduced to facilitate deformation with respect to the vehicle inner side that greatly contributes to the traction performance in the asymmetric pattern. For this reason, the ground contact area can be increased inside the vehicle even when the ground contact center moves to the vehicle interior and the load is low. In addition, the spring constant can be reduced to suppress tire bounce due to road surface irregularities, so it is possible to increase the contact time on the inside of the vehicle, and coupled with the increase in the contact area, the effect of improving the traction performance due to the asymmetric pattern Can be fully exhibited.

  On the other hand, for the outside of the vehicle, which has a large contribution to the grip performance (lateral grip performance) during cornering in the asymmetric pattern, the side rigidity is maintained, so that the effect of improving the grip performance by the asymmetric pattern should be fully exhibited. Can do. Thus, the pneumatic tire of the present invention can sufficiently exhibit the effect of the asymmetric pattern and improve the grip performance and the traction performance at a higher level.

It is sectional drawing which shows one Example of the pneumatic tire of this invention. It is sectional drawing which shows the tire half part inside a vehicle. It is sectional drawing which compares and shows the bead part of a vehicle inner side and a vehicle outer side. It is sectional drawing which compares and shows the buttress part of a vehicle inner side and a vehicle outer side. It is an expanded view which shows a tread pattern.

Hereinafter, embodiments of the present invention will be described in detail.
In FIG. 1, a pneumatic tire 1 according to this embodiment includes a main body portion 6A that extends from a tread portion 2 through a sidewall portion 3 to a bead core 5 of a bead portion 4, and the bead core 5 from both ends of the main body portion 6A. Is provided with a carcass 6 having a folded portion 6B folded from the inner side to the outer side in the tire axial direction, and a belt layer 7 disposed on the outer side in the radial direction of the carcass 6 and inside the tread portion 2.

  Each bead portion 4 is provided with a bead apex rubber 8 that tapers radially outward from the bead core 5 and has a sidewall in the upper sidewall region 3U from the tire maximum width position Pm to the tread end TE. A rib-shaped cut protector 11 is formed which protrudes from the outer surface 3S and extends continuously in the tire circumferential direction.

  The tread portion 2 is formed with an asymmetric tread pattern having different patterns on both sides of the tire equatorial plane Co. This asymmetric tread pattern has a so-called land ratio of 40 to 65%. As shown in FIG. 5, when the vehicle is mounted, the tread half TE 2i that is on the inner side of the vehicle with respect to the tire equatorial plane Co is placed on the tread edge TEi on the inner side of the vehicle. A plurality of lateral grooves 12 extending from the tire toward the tire equatorial plane Co and spaced apart in the circumferential direction are arranged, and the tread half portion 2o on the vehicle outer side extends from the tread end TEo on the vehicle outer side to the tire equatorial plane Co. A plurality of outer lateral grooves 13 extending in the circumferential direction and spaced apart in the circumferential direction are arranged. In this example, the inner and outer lateral grooves 12 and 13 communicate with each other.

  The angle θi of the inner lateral groove 12 with respect to the tire axial direction is set smaller than the angle θo of the outer lateral groove 13 with respect to the tire axial direction. As a result, in the tread half portion 2i inside the vehicle, which greatly contributes to the traction performance, the circumferential force received from the road surface is relatively increased, and the traction performance can be improved, and the grip performance (lateral grip performance) can be improved. In the tread half portion 2o outside the vehicle that greatly contributes to the tire, the force in the tire axial direction received from the road surface is relatively increased, and the grip performance (lateral grip performance) can be improved.

  Specifically, in the asymmetric tread pattern of the present example, the tread half portion 2i on the vehicle inner side is provided with outer longitudinal joint grooves 14a and 14b in the tire axial direction that join between the inner lateral grooves 12 and 12 adjacent in the circumferential direction. In addition, the tread half portion 2o outside the vehicle has three longitudinally connecting grooves 15a, 15m, and 15b in the tire axial direction that connect between the outer lateral grooves 13 and 13 adjacent in the circumferential direction. Arranged. In this example, the longitudinal joint groove 14b extends in the circumferential direction, and the other longitudinal joint grooves 14a, 15a, 15m, and 15b are formed as inclined grooves that are inclined with respect to the circumferential direction. The inclination angle of the inclined groove with respect to the tire axial direction is at least larger than the angle θo, and is usually larger than 45 ° and further larger than 60 °. Further, a sub horizontal groove 16 substantially parallel to the inner horizontal groove 12 is formed between the longitudinal connecting grooves 14b and 15a.

  As a result, a longitudinal block row Rib divided by the inner lateral groove 12 is formed between the tread end TEi and the longitudinal groove 14b, and between the longitudinal grooves 14b and 14a and the longitudinal groove. Between the horizontal grooves 14a and 15a, rows Rim and Ria of horizontally long blocks divided by the inner horizontal grooves 12 and the sub horizontal grooves 16 are formed. A row Rob of substantially triangular blocks divided by the outer lateral groove 13 is formed between the tread end TEo and the longitudinal groove 15b, and between the longitudinal grooves 15b and 15m and the longitudinal groove. Between 15 m and 15 a, rows of vertically long blocks Rom and Roa divided by the outer lateral grooves 13 are formed.

  Here, the horizontally long block means a block whose block length Lx on the tire axial direction side is larger than the block length Ly on the circumferential direction side, and the vertically long block means a block length Lx on the tire axial direction side. Means a block smaller than the block length Ly on the circumferential side. The block length Lx is a width between the block side edges on the tire axial direction side, and is defined as an average when the width is not constant. The block length Ly is a width between the block side edges on the tire circumferential direction side, and is defined as an average when the width is not constant.

  Therefore, the asymmetric tread pattern of this example is formed of a block pattern, and two horizontally long blocks Rim and Ria are arranged in the tread half portion 2o inside the vehicle. The tread half 2o outside the vehicle is provided with two vertically long blocks Rom and Roa and does not include a horizontally long block. By setting it as such a block pattern, both grip performance (lateral grip performance) and traction performance can be improved more.

  Note that the width, depth, and the like of the lateral grooves 12, 13, the longitudinal joint grooves 14a, 14b, 15a, 15m, 15b, and the auxiliary lateral groove 16 are not particularly limited. Those having a width of about 4 to 20 mm and a groove depth of about 9 to 15 mm can be suitably used.

  Next, the carcass 6 is composed of a plurality of carcass plies including a first carcass ply 6a arranged closest to the tire lumen and a second carcass ply 6b placed on the outer side thereof. In this example, a case of two carcass plies 6a and 6b is shown. Each of the carcass plies 6a and 6b includes a carcass cord arranged at an angle of, for example, 75 to 90 ° with respect to the tire equatorial plane Co. As the carcass cord, an organic fiber cord such as polyester, nylon, or rayon is suitably employed.

  In the second carcass ply 6b, as shown in FIG. 3, the folding height Hbi in the radial direction from the bead base line BL of the folding portion 6Bbi inside the vehicle is equal to the bead baseline BL of the folding portion 6Bbo outside the vehicle. Is set to be smaller than the folding height Hbo in the radial direction. In the other carcass ply, in this example, the first carcass ply 6a, as shown in FIG. 1, the folding height Hai of the folding portion 6Bai on the vehicle inner side and the folding height Hao of the folding portion 6Bao on the vehicle outer side are the same. Set to height. In this example, the folding heights Hai and Hao of the first carcass ply 6a are larger than the folding heights Hbi and Hbo of the second carcass ply 6b, whereby the folding end of the second carcass ply 6b is set. The coating is protected to prevent damage from the folded end. The folded portion 6Ba itself of the first carcass ply 6a is preferably terminated under the buttress portion where the tire is less deformed or under the belt layer 7 to prevent damage from the folded end.

  The folding height difference (Hbo-Hbi) in the second carcass ply 6b is preferably in the range of 20 to 60 mm, and the folding height difference Hbo on the outside of the vehicle is preferably in the range of 55 to 95 mm. It is.

  The bead apex rubber 8 is made of hard rubber having a rubber hardness of 70 to 90 °, and extends from the bead core 5 between the main body portion 6A and the folded portion 6B in a tapered manner outward in the radial direction. The rubber hardness Hs is a durometer A hardness measured in a 23 ° C. environment by a durometer type A based on JIS-K6253.

  Also in this bead apex rubber 8, the apex height 8Hi in the radial direction from the bead base line BL of the bead apex rubber 8i inside the vehicle is the radial apex height from the bead base line BL in the bead apex rubber 8o outside the vehicle. It is smaller than 8Ho. The apex height difference (8Ho-8Hi) is preferably in the range of 5 to 30 mm, and the apex height 8Ho outside the vehicle is preferably in the range of 45 to 65 mm.

  The belt layer 7 is formed of two or more belt plies 7a and 7b having a belt cord arranged at an angle of, for example, 10 to 45 ° with respect to the tire equatorial plane Co, in this example. This belt layer 7 has a belt cord that crosses between plies to increase belt rigidity, and substantially reinforces substantially the entire width of the tread portion 2 with a tagging effect. As the belt cord, a steel cord is used in this example, but a high modulus organic fiber cord such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyamide, or the like can be used as necessary.

  Further, the side wall 3 has an upper side wall region 3U extending from the tread edge TE to the tire maximum width position Pm in order to protect it from contact with crushed stones, rubble, vegetation, etc. when traveling on rough terrain. A rib-shaped cut protector 11 is formed which protrudes from 3S and extends continuously in the tire circumferential direction. The cut protector 11 protects the sidewall portion 3 from contact with crushed stone, rubble, vegetation, and the like when traveling on rough terrain. Although the height h1 of the cut protector 11 protruding from the sidewall outer surface 3S is not particularly restricted, a range of 2 to 6 mm can be suitably employed as in the case of a conventional rally tire. In the present embodiment, the cut protector 11 is formed with at least one, preferably a plurality of concave grooves 17 extending continuously in the tire circumferential direction, thereby imparting flexibility to the cut protector 11 and reducing ride comfort. Is suppressed. The concave groove 17 has a substantially U-shaped cross section, and its depth h2 is set in a range of 0.5 to 1.0 times the height h1.

  In the present embodiment, as shown in FIG. 4, also in the cut protector 11, the cut protector 11 o outside the vehicle has a radial distance from the tread end TEo at the radially outer end (hereinafter referred to as protector outer end distance). 11Lo is smaller than the radial distance 11Li from the tread end TEi at the radially outer end of the cut protector 11i inside the vehicle. The distance difference (11Li-11Lo) is preferably in the range of 7 to 20 mm, and the distance 11Lo from the outer tread edge of the cut protector outside the vehicle is preferably 20 to 30 mm.

  Thus, in the tire of this embodiment, the folding height of the second carcass ply 6b, the apex height of the bead apex rubber 8, and the protector outer end distance of the cut protector 11 are different between the vehicle outer side and the vehicle inner side, respectively. I am letting.

  As a result, it is possible to reduce the side rigidity and facilitate deformation on the inside of the vehicle that greatly contributes to the traction performance in the asymmetric pattern. Therefore, the ground contact area can be increased on the vehicle inner side even when the load is low. In addition, since the inside of the vehicle is easily deformed, it is possible to increase the contact time on the inside of the vehicle, such as suppressing the spring of the tire due to the unevenness of the road surface. And, by the synergistic effect of the increase in the contact time and the increase in the contact area, the effect of improving the traction performance by the asymmetric pattern can be sufficiently exhibited.

  On the other hand, on the outside of the vehicle, where the contribution to the grip performance (lateral grip performance) during cornering is large in the asymmetric pattern, the side rigidity is maintained higher than that on the inside of the vehicle. High performance can be achieved. Thus, in the pneumatic tire of the present invention, the structure of the carcass 6, the bead apex rubber 8, and the cut protector 11 is asymmetric between the vehicle outer side and the vehicle inner side in accordance with the tread pattern. It is possible to fully exhibit the grip performance (lateral grip performance) and the traction performance at a high level.

  Here, it is important to make the three of the folding height, apex height, and protector outer end distance different between the vehicle outer side and the vehicle inner side, respectively. If one is missing, the rigidity balance between the bead side and the buttress side deteriorates and the deformation tends to be partially biased. As a result, it is difficult to ensure a large amount of deformation of the entire sidewall portion 3 on the vehicle inner side, and it is difficult to maintain high side rigidity on the vehicle outer side, so that the above effects can be effectively exhibited. Becomes difficult.

  Regarding the folding height, as described above, the folding height difference (Hbo-Hbi) is preferably in the range of 20 to 60 mm, and when the difference (Hbo-Hbi) is less than 20 mm, the difference between the vehicle inner side and the vehicle outer side. In the meantime, the difference in side rigidity and the difference in deformation amount are excessively small, and it is difficult to effectively exhibit the above effects. On the other hand, if the difference (Hbo-Hbi) exceeds 60 mm, the stress tends to be concentrated at the folded end of the second carcass ply 6b, which is disadvantageous for durability.

  As for the apex height, as described above, the apex height difference (8Ho-8Hi) is preferably in the range of 5 to 30 mm. If the difference (8Ho-8Hi) is less than 5 mm, the difference between the vehicle inner side and the vehicle outer side. In the meantime, the difference in side rigidity and the difference in deformation amount are excessively small, and it is difficult to effectively exhibit the above effects. On the other hand, if the difference (8Ho-8Hi) exceeds 30 mm, the stress tends to be concentrated on the outer end of the bead apex rubber 8 and damage is disadvantageous.

  As for the distance between the outer ends of the protectors, the difference (11Li-11Lo) is preferably in the range of 7 to 20 mm as described above, and when the difference (11Li-11Lo) is less than 7 mm, the distance between the vehicle inner side and the vehicle outer side is reduced. A difference in rigidity and a difference in deformation amount are excessively small, and it becomes difficult to effectively exhibit the above effects. On the other hand, if the difference (11Li-11Lo) exceeds 20 mm, it becomes difficult to achieve the original function of the cut protector 11 such that the cut damage from crushed stones cannot be sufficiently suppressed on the inside of the vehicle.

  In this example, in order to improve the grip performance (lateral grip performance) and the traction performance at a higher level, as shown in FIG. 1, an aramid fiber cord is arranged only on the sidewall portion 3 outside the vehicle. The aramid reinforcing layer 20 is provided. The aramid reinforcing layer 20 is composed of, for example, one reinforcing ply in which aramid fiber cords are arranged at an angle of 35 to 60 ° with respect to the tire circumferential direction, and as shown in FIGS. By being arranged on the outer side in the tire axial direction of 6A, it is possible to prevent large scratches caused by crushed stone or the like from penetrating through the sidewall portion 3 and reaching the main body portion 6A. However, in this example, in addition to the above-described damage prevention effect, the grip performance (side grip performance) is suppressed while suppressing an increase in side rigidity inside the vehicle, which greatly contributes to traction performance, by providing only in the sidewall portion 3 on the outside of the vehicle. The side rigidity on the outside of the vehicle, which greatly contributes to the vehicle), can be increased, and a higher level of both grip performance (lateral grip performance) and traction performance can be achieved.

  The aramid reinforcing layer 20 extends inward and outward in the radial direction from the maximum tire width position Pm, and the radial width is preferably 40 mm or more, more preferably 50 mm or more. In particular, as in this example, the radially inner end of the aramid reinforcing layer 20 forms an overlapping portion GL that overlaps with the bead apex rubber 8 in and out of the tire axial direction, and the radially outer end of the aramid reinforcing layer 20 extends in and out of the belt layer 7 in the radial direction. Arrangement so as to form overlapping overlapping portions GU is more preferable from the viewpoints of damage prevention effect and compatibility between grip performance (lateral grip performance) and traction performance.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  A rally passenger car tire (tire size 205 / 65R15) having the tire configuration shown in FIG. 1 and the tread pattern shown in FIG. 5 was prototyped based on the specifications shown in Table 1.

  Each sample tire was mounted on a domestic four-wheel drive vehicle (2000 cc), a time trial was performed on a dirt test course (about 1.5 km per round), and the best time of two runs was compared. In addition, the grip performance (lateral grip performance) and traction performance during cornering during a time trial were evaluated by a five-point method using Comparative Example 1 as three points by sensory evaluation of the driver. The higher the number, the better.

  Each tire employs the asymmetric pattern shown in FIG. 5 as a tread pattern, and the angle θi of the inner lateral groove with respect to the tire axial direction is 0 °, and the angle θo of the outer lateral groove with respect to the tire axial direction is 25 °.

The specifications are substantially the same except those listed in Table 1.
<Bead apex rubber>
-The rubber hardness of the bead apex rubber is 80 °:
-Apex height 8Ho outside the vehicle is 50mm:
<Carcass ply>
-The folding height Hbo of the second carcass ply is 70 mm:
-Folding heights Hai, Hao of the first carcass ply are 85 mm:
<Cut protector>
The distance 11Lo from the tread edge of the outer edge of the cut protector outside the vehicle is 25 mm:
The raised height h1 of the cut protector is 3 mm, and the depth h2 of the concave groove is 3 mm:
<Aramid reinforcement layer>
・ Cord angle is 45 ° (angle with respect to circumferential direction):
・ The radial width is 115mm:
The tires are the same.

  As shown in Table 1, it can be confirmed that the example products can improve both the grip performance (lateral grip performance) and the traction performance at a high level and can shorten the lap time.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 2i, 2o Tread half part 3 Side wall part 3U Upper side wall area | region 3S Side wall outer surface 4 Bead part 5 Bead core 6 Carcass 6A Main-body part 6B, 6Bbi, 6Bbo Folding part 6a 1st carcass ply 6b Second carcass ply 7 Belt layer 8, 8i, 8o Bead apex rubber 11, 11i, 11o Cross groove 13 in cut protector 12 Outer horizontal groove 20 Aramid reinforcement layer BL Bead base line Co Tire equatorial plane Lx, Ly Block length Pm Maximum tire width position TE, TEi, TEo Tread edge

Claims (3)

A carcass having a main body part that extends from the tread part through the sidewall part to the bead core of the bead part, and a turn-back part that turns around the bead core from both ends of the main body part outward from the inside in the tire axial direction;
A bead apex rubber that extends from the bead core to the outside in the radial direction through the space between the body portion and the folded portion;
And a pneumatic tire provided with a rib-shaped cut protector that is arranged in an upper sidewall region extending from the tire maximum width position to the tread edge, and that rises from the sidewall outer surface and continuously extends in the tire circumferential direction,
The tread portion has an asymmetric tread pattern with different patterns on both sides of the tire equatorial plane, and the inner half of the tread half that is inside the vehicle from the tire equatorial plane when the vehicle is mounted extends from the tread edge toward the tire equatorial plane. The lateral grooves of the outer side of the vehicle and the outer half of the tread on the outer side of the vehicle are respectively provided with outer lateral grooves extending from the tread end toward the tire equatorial plane in the circumferential direction, and the angle θi of the inner lateral groove with respect to the tire axial direction It is smaller than the angle θo of the outer lateral groove with respect to the tire axial direction,
The carcass is composed of a plurality of carcass plies including a first carcass ply arranged closest to the tire lumen side and a second carcass ply placed on the outside thereof,
Moreover, the folding height in the radial direction from the bead base line of the folded portion of the second carcass ply is such that the folded height of the folded portion on the vehicle inner side is smaller than the folded height of the folded portion on the vehicle outer side, and In other carcass plies, the folding height of the folding part inside the vehicle is the same as the folding height of the folding part outside the vehicle,
The apex height in the radial direction from the bead base line of the bead apex rubber is such that the apex height of the bead apex rubber inside the vehicle is smaller than the apex height of the bead apex rubber outside the vehicle,
The radial distance from the tread end of the cut protector in the radial direction to the radial end of the cut protector is such that the radial distance of the cut protector outside the vehicle is smaller than the radial distance of the cut protector inside the vehicle. tire. The asymmetric tread pattern is a block pattern,
The tread half portion on the vehicle inner side includes a row of horizontally long blocks in which a horizontally long block whose block length on the tire axial direction side is larger than the block length on the circumferential side is arranged in the circumferential direction,
The tread half portion outside the vehicle includes a row of vertically long blocks in which a longitudinal block whose block length on the tire axial direction side is smaller than a block length on the circumferential side is arranged in the circumferential direction, and does not include a row of horizontally long blocks. The pneumatic tire according to claim 1.   The aramid reinforcement layer in which aramid fiber cords are arranged is disposed on the sidewall portion on the vehicle outer side, and the aramid reinforcement layer is not disposed on the sidewall portion on the vehicle inner side. Pneumatic tire.

Images