JP2010120479A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of improving durability in high-speed traveling, while maintaining driving stability in high-speed traveling well, under a condition wherein a large negative camber is set. <P>SOLUTION: Wing chip rubber layers 1C and 1D are arranged to be adjacent to cap tread rubber layers 1A and 1B in both shoulder regions of a tread part 1, and tan δ of a rubber composition, which structures the wing chip rubber layer 1C arranged outside a vehicle in installation in the vehicle, at 60°C is set to be higher than tan δ of a rubber composition, which structures the wing chip rubber layer 1D arranged inside the vehicle in installation in the vehicle, at 60°C. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pneumatic tire having a carcass layer having a one-ply structure and a winding portion extending to a lower region of the belt layer so as to overlap an end portion of the belt layer, and more specifically, a large negative camber is set. It is related with the pneumatic tire which made it possible to improve high-speed durability, maintaining favorable steering stability at the time of high-speed driving | running | working on conditions.

  In recent years, the demand for weight reduction of pneumatic tires mounted on vehicles that are expected to run at high speed, such as sports cars, has become stricter. It is required to ensure the handling stability.

  On the other hand, a carcass layer having a one-ply structure is mounted between a pair of bead portions, a belt layer is disposed on the outer peripheral side of the carcass layer in the tread portion, and the carcass layer is disposed around each bead core disposed on each bead portion. The bead filler disposed on the bead core is sandwiched between the body portion and the winding portion of the carcass layer, and the lower portion of the belt layer is overlapped with the end portion of the belt layer. A pneumatic tire extended to the region has been proposed (see, for example, Patent Documents 1 to 3).

  A pneumatic tire having a carcass layer that extends to the lower region of the belt layer so as to overlap the end portion of the belt layer with a one-ply structure as described above is lightweight by using the carcass layer as one ply. In the sidewall portion, excellent steering stability can be exhibited by overlapping the main body portion and the winding portion of the carcass layer. Further, when a side reinforcing layer is embedded in the pair of left and right bead portions, it is possible to ensure a higher level of steering stability.

  However, a large negative camber is usually set for a vehicle that is assumed to run at high speed, and when a side reinforcing layer is embedded in the bead portion of a pneumatic tire mounted on such a vehicle, the tire flex zone is sufficient. Therefore, there is a problem that deterioration of high-speed durability is deteriorated.

Also, a pneumatic tire having a carcass layer with a one-ply structure that extends to the lower region of the belt layer so that the winding portion overlaps the end of the belt layer, for example, when the tire runs continuously on a circuit, As a result, the steering stability tends to decrease. Therefore, it is also required to suppress a change in performance of steering stability due to continuous running for a pneumatic tire that achieves both weight reduction and steering stability based on the above structure.
JP-A-5-238208 JP-A-6-16609 JP 2000-52709 A

  An object of the present invention is to provide a pneumatic tire capable of improving high-speed durability while maintaining good steering stability during high-speed driving under conditions where a large negative camber is set. is there.

  In order to achieve the above object, the pneumatic tire of the present invention is a pneumatic tire in which the mounting direction of the front and back of the tire is specified when the vehicle is mounted, and the cord angle between the pair of bead portions with respect to the tire circumferential direction is 75 °. A carcass layer having a one-ply structure in a range of ˜90 ° is mounted, a belt layer is disposed on the outer periphery side of the carcass layer in the tread portion, and the carcass layer is disposed on the inner side of the tire around the bead core disposed in each bead portion. The bead filler disposed on the bead core is sandwiched between the body portion and the winding portion of the carcass layer, and the winding portion of the carcass layer is overlapped with the end portion of the belt layer. In the pneumatic tire extended to the lower region, both shoulder regions of the tread part are adjacent to the cap tread rubber layer, respectively. The rubber composition constituting the wing tip rubber layer on the inner side of the vehicle when the vehicle is mounted is defined as tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer on the outer side of the vehicle at the time of wearing the vehicle. It is characterized by being higher than tan δ at 60 ° C.

  In the present invention, in order to achieve both weight reduction and steering stability, an air having a carcass layer having a one-ply structure in which a winding portion extends to a lower region of the belt layer so as to overlap an end portion of the belt layer. Even when the large negative camber is set, it is possible to make the tire layer and the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer inside the vehicle relatively low. Heat generation near the edge can be suppressed and high-speed durability can be improved. On the other hand, by making tan δ of the wing tip rubber layer outside the vehicle relatively high, it is possible to maintain good steering stability during high-speed traveling.

In the present invention, the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer outside the vehicle is set to 0.10 to 0.30, and the rubber composition constituting the wing tip rubber layer inside the vehicle at 60 ° C. The tan δ is preferably 0.15 or less. The difference between the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer outside the vehicle and the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer inside the vehicle shall be 0.05 or more. Is preferred. Then, the cross-sectional area of the tire meridian section of each wing tip rubber layer is preferable to be 20mm ² ~50mm ^2. Thereby, based on the asymmetric structure of the wing tip rubber layer, it becomes possible to achieve both higher handling stability and high speed durability at high speeds.

  Furthermore, in the present invention, the height of the bead filler from the bead heel is preferably 30% or less of the tire cross-sectional height, and the tan δ at 60 ° C. of the rubber composition constituting the bead filler is preferably 0.20 or less. Thus, by reducing the bead filler that is repeatedly deformed during rolling of the tire and reducing the tan δ at 60 ° C. of the rubber composition constituting the bead filler, the heat generation of the tire due to continuous running on the circuit is suppressed. , The performance change of the steering stability can be suppressed. Thereby, it is possible to maintain the initial steering stability for a long time in continuous running.

  In the tread portion, at least two kinds of cap tread rubber layers having different rubber compositions are arranged adjacent to each other in the tire width direction, and tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer on the vehicle outer side is determined. It is preferable to make it higher than tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer on the inside of the vehicle. Generally, when the tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer is increased, the steering stability is improved, but the performance of the steering stability due to heat generation is likely to occur. On the other hand, as described above, tan δ is relatively high on the outside of the vehicle and tan δ is relatively low on the inside of the vehicle, thereby improving the steering stability and changing the performance of the steering stability by continuous running. Can be suppressed.

  The ratio of the maximum value tan δH and the minimum value tan δL (tan δH / tan δL) of tan δ at 60 ° C of the rubber composition constituting at least two kinds of cap tread rubber layers is preferably in the range of 1.05 to 1.80. . Thereby, the effect which suppresses the performance change of the steering stability by continuous driving | running | working can be fully acquired, improving steering stability.

  It is preferable that the boundary between at least two types of cap tread rubber layers is disposed below the main groove extending in the tire circumferential direction at the tread portion. Thereby, even if it is a case where it is a case where it is going to acquire the effect which suppresses the performance change of steering stability by continuous run, improving steering stability, it can control the occurrence of uneven wear by the difference in rubber composition. it can.

  Further, at least one main groove extending in the tire circumferential direction is provided in the tread portion, and the groove area ratio GAo from the tread center to the ground contact area outside the vehicle is the groove area ratio GAi from the tread center to the ground contact area inside the vehicle. It is preferable to form an asymmetric tread pattern that is smaller than that. Thereby, the effect which suppresses the performance change of the steering stability by continuous driving | running | working can be fully acquired, improving steering stability.

  In the asymmetric tread pattern, the groove area ratio GA in the entire ground contact area is in the range of 20% to 40%, and the groove area ratio GAo in the ground contact area outside the vehicle and the groove area ratio GAi in the ground contact area inside the vehicle are The difference (GAi−GAo) is preferably in the range of 1% to 15%. Thereby, the effect which suppresses the performance change of the steering stability by continuous driving | running | working can be fully acquired, improving steering stability.

  In the present invention, the height of the bead filler from the bead heel is a height measured under the tire dimension measurement conditions defined in the standard on which the tire is based, and the height of the bead filler from the bead heel corresponding to the reference position of the rim diameter. This is the dimension in the tire radial direction up to the top. Tan δ at 60 ° C. is measured using a viscoelastic spectrometer (manufactured by Toyo Seiki Seisakusho) under the conditions of temperature 60 ° C., frequency 20 Hz, initial strain 10%, and dynamic strain ± 2%. The groove area ratio is the ratio (%) of the groove area in the ground contact area to the total area of the ground contact area measured under the tire static load radius measurement condition defined by the standard on which the tire is based.

  The present invention can be applied to various types of pneumatic tires. However, when the present invention is applied to a pneumatic tire having a tire size having a flatness ratio of 50% or less with a narrow flex zone, a remarkable effect can be obtained. In particular, when applied to a pneumatic tire mounted on a vehicle having a camber angle of −0.5 ° to −4.0 °, a remarkable effect can be obtained.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a pneumatic tire according to an embodiment of the present invention. This pneumatic tire is a tire in which the mounting direction of the tire front and back when the vehicle is mounted is designated. In FIG. 1, IN is the inside of the vehicle when the vehicle is mounted, and OUT is the outside of the vehicle when the vehicle is mounted.

  In FIG. 1, 1 is a tread portion, 2 is a sidewall portion, and 3 is a bead portion. As shown in FIG. 1, a single carcass layer 4 composed of a plurality of aligned carcass cords is mounted between a pair of bead portions 3 and 3. As the carcass cord, an organic fiber cord made of rayon, polyester, nylon, aromatic polyamide or the like is preferably used. The cord angle of the carcass layer 4 with respect to the tire circumferential direction is set in the range of 75 ° to 90 °, preferably in the range of 80 ° to 87 °. The cord angle of the carcass layer 4 with respect to the tire circumferential direction is, for example, a high angle when the load factor is low, and a low angle when the load factor is high. The performance can be maintained. The carcass layer 4 is wound up around the bead core 5 from the inside of the tire to the outside. That is, the carcass layer 4 includes a main body portion 4a and a winding portion 4b with the bead core 5 as a boundary.

  In each bead portion 3, a bead filler 6 made of a rubber composition having a high hardness is disposed on the outer periphery of the bead core 5, and the bead filler 6 is sandwiched between the main body portion 4 a and the winding portion 4 b of the carcass layer 4. . Each bead portion 3 is embedded with a side reinforcing layer 7 including a reinforcing cord inclined with respect to the tire circumferential direction. In order to obtain a good reinforcing effect, the cord angle of the side reinforcing layer 7 with respect to the tire circumferential direction is desirably set to 15 ° to 65 °. As the reinforcing cord of the side reinforcing layer 7, a steel cord can be used in addition to an organic fiber cord made of polyester, nylon, aromatic polyamide or the like. When an organic fiber cord is used as the reinforcing cord of the side reinforcing layer 7, the side reinforcing layer 7 is preferably arranged so as to wrap the bead core 5 and the bead filler 6 as illustrated. When using a steel cord as the reinforcing cord of the side reinforcing layer 7, the side reinforcing layer 7 may be disposed between the bead filler 6 and the winding portion 4 b of the carcass layer 4.

  On the other hand, a plurality of belt layers 8 including reinforcing cords inclined with respect to the tire circumferential direction are disposed on the outer peripheral side of the carcass layer 4 in the tread portion 1. Further, a belt cover layer 9 including reinforcing cords oriented in the tire circumferential direction is disposed on the outer peripheral side of the belt layer 8. And the winding part 4b of the carcass layer 4 mentioned above is extended to the downward area of this belt layer 8 so that it may overlap with the edge part of the tire width direction of the belt layer 8. FIG.

  In the tread portion 1, two types of cap tread rubber layers 1A and 1B having different rubber compositions are disposed adjacent to each other in the tire width direction. Wing tip rubber layers 1C and 1D are disposed in both shoulder regions of the tread portion 1 so as to be adjacent to the cap tread rubber layers 1A and 1B, respectively.

  In the pneumatic tire described above, in order to achieve both weight reduction and steering stability, a carcass having a one-ply structure in which the winding portion 4b extends to the lower region of the belt layer 8 so as to overlap the end portion of the belt layer 8. Although the layer 4 is provided, the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer 1C that becomes the outside of the vehicle when the vehicle is mounted is the rubber constituting the wing tip rubber layer 1D that becomes the inside of the vehicle when the vehicle is attached. It is higher than tan δ at 60 ° C. of the composition.

  Thus, in the pneumatic tire in which the mounting direction of the tire front and back when the vehicle is mounted is specified, by relatively reducing the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer 1D on the vehicle inner side, Even under conditions where a large negative camber is set, heat generation near the edge of the belt layer 8 can be suppressed and high-speed durability can be improved. For example, when a high-speed durability test with a camber is performed, separation between the belt layer 8 and the carcass layer 4, between the belt layer 8 and the cap tread rubber layer, and between the carcass layer 4 and the side rubber layer. Can be suppressed and the level of durability can be increased. On the other hand, by relatively increasing the tan δ of the wing tip rubber layer 1C on the outside of the vehicle, it is possible to maintain good steering stability during high-speed driving, and particularly to improve high-speed lane change performance. .

  Here, the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer 1C on the outside of the vehicle is set in the range of 0.10 to 0.30, and the rubber composition constituting the wing tip rubber layer 1D on the inside of the vehicle. The tan δ at 60 ° C. of the product is set in the range of 0.15 or less. If the tan δ of the wing tip rubber layer 1C on the outside of the vehicle is less than 0.10, the grip difference from the cap tread rubber layer 1A becomes large, so it becomes difficult to ensure the driving stability on the dry road surface, and conversely 0.30 Exceeding this makes it difficult to ensure high-speed durability due to heat generation. On the other hand, if tan δ of the wing tip rubber layer 1D inside the vehicle exceeds 0.15, it becomes difficult to ensure high-speed durability due to heat generation. Further, in order to achieve both the handling stability and the high speed durability during high speed running, the difference between the two tan δ is preferably 0.05 or more.

Cross-sectional area of each wing tip rubber layer 1C, 1D of the tire meridian section is set in a range of 20mm ² ~50mm ^2. When the cross-sectional areas of the wing tip rubber layers 1C and 1D are less than 20 mm ² , the effect based on the physical properties becomes insufficient. Further, the cross-sectional area of the wing tip rubber layers 1C and 1D is 50 mm ² or less, and is distinguished from the side rubber layer 2A disposed on the sidewall portion 2.

  In the pneumatic tire, the height FH of the bead filler 6 from the bead heel is set to 30% or less of the tire cross-section height SH, and the tan δ at 60 ° C. of the rubber composition constituting the bead filler 6 is 0.20 or less. Is set to

  In a pneumatic tire, the deformation of the bead filler 6 is repeated at the time of rolling. When the amount of heat generated due to the bead filler 6 increases thereby, a change in performance of steering stability becomes remarkable. Therefore, by lowering the bead filler 6 and reducing its cross-sectional area, the tan δ at 60 ° C. of the rubber composition constituting the bead filler 6 is reduced to suppress the heat generation of the tire due to continuous running on the circuit. , The performance change of the steering stability can be suppressed. As a result, it is possible to maintain the initial steering stability for a long time in continuous running.

  Here, if the height FH of the bead filler 6 is more than 30% of the tire cross-section height SH, the effect of suppressing change in performance of steering stability becomes insufficient. The lower limit value of the height FH of the bead filler 6 is preferably 10 mm.

  Further, if the tan δ at 60 ° C. of the rubber composition constituting the bead filler 6 is more than 0.20, the effect of suppressing the performance change of the steering stability becomes insufficient. The lower limit value of tan δ at 60 ° C. of the rubber composition constituting the bead filler 6 is preferably 0.03.

  In the tire in which the tire front and back mounting directions are specified as described above, as shown in FIG. 1, two types of cap tread rubber layers 1A and 1B having different rubber compositions are adjacent to the tread portion 1 in the tire width direction. Is arranged. The tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer 1A on the vehicle outer side is higher than the tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer 1B on the vehicle inner side. Yes. By providing a difference in the tan δ of the rubber composition of the cap tread rubber layers 1A and 1B, it is possible to suppress the heat generation in the tread portion 1 and to suppress the change in performance of the steering stability while improving the steering stability. become. The range of tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer is preferably 0.10 to 0.50.

  The ratio of tan δH at 60 ° C. of the rubber composition constituting the cap tread rubber layer 1A to tan δL at 60 ° C. of the rubber composition constituting the cap tread rubber layer 1B (tan δH / tan δL) is 1.05-1.80. More preferably, it is set in the range of 1.10 to 1.50. If this ratio (tan δH / tan δL) is too small, the effect of suppressing the change in performance of steering stability is reduced, and conversely, if it is too large, the originally required grip force cannot be obtained. Note that the boundary between the cap tread rubber layers 1A and 1B is preferably disposed below the main groove 60 extending in the tire circumferential direction in the tread portion 1. Thereby, generation | occurrence | production of the partial wear by the difference in a rubber composition can be suppressed.

  In this embodiment, two types of cap tread rubber layers 1A and 1B having different rubber compositions are arranged in the tread portion 1, but two or more types of cap tread rubber layers are arranged adjacent to each other in the tire width direction. be able to.

  In this embodiment, an SOC (side-on-crown) structure in which the side rubber layer 2A is disposed so as to cover the wing chip rubber layers 1C and 1D is employed, but the wing chip rubber layer is covered so as to cover the side rubber layer 2A. It is also possible to adopt a COS (crown on side) structure in which 1C and 1D are arranged (see FIG. 3). In the case of the SOC structure, it is particularly effective for preventing belt edge separation. On the other hand, in the case of the COS structure, since the wing tip rubber layers 1C and 1D are exposed on the outer surface of the tire, it is possible to improve grip performance based on the wing tip rubber layers 1C and 1D.

  FIG. 2 shows a tread pattern of a pneumatic tire according to an embodiment of the present invention. In FIG. 2, CL is a tread center. As shown in FIG. 2, a plurality of main grooves 60 extending in the tire circumferential direction are formed in the tread portion 1, and a plurality of land portions 10, 20, 30 are formed by the main grooves 60 from the vehicle outer side toward the vehicle inner side. , 40, 50 are partitioned. The land portion 10 located on the outermost side of the vehicle has a narrow groove 11 extending in the tire circumferential direction, a plurality of lateral grooves 12 extending in the tire width direction on the tread shoulder side from the narrow groove 11, and at least the tread than the narrow groove 11. A plurality of narrow grooves 13 extending in the tire width direction on the center side are formed. The land portion 20 is formed with narrow grooves 21 extending in the tire circumferential direction and a plurality of cutout grooves 22 extending in the tire width direction. The land portion 30 is formed with a plurality of curved grooves 31 extending while being curved in the tire circumferential direction, and a plurality of cutout grooves 32 extending in the tire width direction. The land portion 40 has a tire circumferential direction. A plurality of curved grooves 41 extending while being curved are formed. A plurality of lateral grooves 51 extending in the tire width direction and a plurality of narrow grooves 52 extending in the tire width direction are formed between the lateral grooves 51 in the land portion 50 located on the innermost side of the vehicle.

  In the pneumatic tire described above, at least one main groove 60 extending in the tire circumferential direction is formed in the tread portion 1, and in the entire ground contact region defined by the ground contact width TCW, in the ground contact region outside the vehicle from the tread center CL. Has an asymmetric tread pattern in which the groove area ratio GAo is smaller than the groove area ratio GAi in the ground contact region inside the vehicle from the tread center CL. Thereby, the effect which suppresses the performance change of the steering stability by continuous driving | running | working can be fully acquired, improving steering stability.

  Here, the groove area ratio GA in the entire ground contact area ranges from 20% to 40%, and the groove area ratio GAo in the ground contact area outside the vehicle from the tread center CL and the groove in the ground contact area inside the vehicle from the tread center CL. The difference from the area ratio GAi (GAi−GAo) is preferably in the range of 1% to 15%, more preferably in the range of 2% to 13%. If this difference (GAi−GAo) is too small, the effect of suppressing the change in performance of the steering stability is reduced. On the other hand, if it is too large, the steering stability is lowered due to insufficient block rigidity.

  With a tire size of 235 / 40R18, a carcass layer having a one-ply structure with a cord angle with respect to the tire circumferential direction of 85 ° is mounted between a pair of bead portions, and a belt layer is disposed on the outer peripheral side of the carcass layer in the tread portion, The carcass layer is wound around the bead core disposed on each bead portion from the inside to the outside of the tire, the bead filler disposed on the bead core is sandwiched between the main body portion and the wound portion of the carcass layer, and the wound portion of the carcass layer is belted In the pneumatic tire extended to the lower region of the belt layer so as to overlap the end of the layer, the height of the bead filler from the bead heel (ratio to the tire cross-section height), the rubber composition constituting the bead filler Tan δ at 60 ° C., t of the rubber composition constituting the wing tip rubber layer on the vehicle outer side and the vehicle inner side at 60 ° C. Comparative Examples 1 to 5 and Examples in which an δ, tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer on the vehicle outer side and the vehicle inner side, and the groove area ratio on the vehicle outer side and the vehicle inner side are set as shown in Table 1-4 tires were produced respectively.

  With respect to these test tires, performance changes in high speed durability, high speed lane change performance, and steering stability were evaluated by the following test methods, and the results are also shown in Table 1.

High speed durability:
The test tire is mounted on a drum testing machine, the load is 0.85 times the maximum load capacity, the air pressure is 250 kPa, the camber angle is -2.5 °, and the speed is from 200 km / h to 10 km / h every 10 minutes. We stepped up step by step and measured the distance traveled until the tire broke down. The evaluation results are shown as an index with Comparative Example 1 as 100. It means that high speed durability is excellent, so that this index value is large.

High-speed lane change performance:
A test tire is fitted to a wheel with a rim size of 18 x 8 J and mounted on a vehicle with a displacement of 4000 cc class (camber angle: -2.5 °). Sensory evaluation was performed on the lane change. The evaluation results are shown as an index with Comparative Example 1 as 100. The larger the index value, the better the high-speed lane change performance.

Steering stability performance change:
The test tire is fitted to a wheel with a rim size of 18 x 8 J and mounted on a vehicle with a displacement of 4000 cc (camber angle: -2.5 °). The test driver runs continuously for 200 km under the condition of air pressure of 250 kPa. The sensory evaluation was performed on the change between the driving stability at the beginning of driving and the driving stability at the end of driving. The evaluation results are indicated by an index with a pass level of 100. A larger index value means less performance change.

  As shown in Table 1, while the tires of Examples 1 to 4 are in good contrast with Comparative Example 1 while maintaining high steering stability during high-speed driving under the condition that a large negative camber is set, It exhibited excellent high-speed durability, and had little change in steering stability performance due to continuous running. On the other hand, Comparative Examples 2 to 5 could not obtain a sufficient improvement effect with respect to steering stability and high speed durability during high speed running.

It is meridian sectional drawing which shows the pneumatic tire which consists of embodiment of this invention. It is a top view which shows the tread pattern of the pneumatic tire which consists of embodiment of this invention. It is meridian sectional drawing which shows the pneumatic tire which consists of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tread part 1A, 1B Cap tread rubber layer 1C, 1D Wing chip rubber layer 2 Side wall part 3 Bead part 4 Carcass layer 4a Body part 4b Roll-up part 5 Bead core 6 Bead filler 7 Side reinforcement layer 8 Belt layer 9 Belt cover layer 60 Main groove

Claims (12)

  A pneumatic tire in which a tire front and back mounting direction is specified when the vehicle is mounted, and a carcass layer having a one-ply structure in which a cord angle with respect to the tire circumferential direction is in a range of 75 ° to 90 ° between a pair of bead portions. The belt layer is disposed on the outer peripheral side of the carcass layer in the tread portion, the carcass layer is wound around the bead core disposed in each bead portion from the inside of the tire to the outside, and the bead filler disposed on the bead core is provided. In the pneumatic tire in which the carcass layer is sandwiched between the main body portion and the winding portion, and the winding portion of the carcass layer is extended to the lower region of the belt layer so as to overlap the end portion of the belt layer, the tread portion Wing tip rubber layers are placed on both shoulder areas so as to be adjacent to the cap tread rubber layer, A pneumatic tire in which the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer outside the vehicle is higher than the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer inside the vehicle when mounted on the vehicle. .   The tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer outside the vehicle is set to 0.10 to 0.30, and the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer inside the vehicle is set. The pneumatic tire according to claim 1, wherein the tire is 0.15 or less.   The difference between the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer outside the vehicle and the tan δ at 60 ° C. of the rubber composition constituting the wing tip rubber layer inside the vehicle is 0.05 or more. The pneumatic tire according to claim 2. The pneumatic tire according to claim 1, the cross-sectional area in the tire meridian cross section of each wing tip rubber layers was 20mm ² ~50mm ^2.   The height from the bead heel of the bead filler is 30% or less of the tire cross-sectional height, and the tan δ at 60 ° C of the rubber composition constituting the bead filler is 0.20 or less. The pneumatic tire described in 1.   At least two kinds of cap tread rubber layers having different rubber compositions are arranged in the tread portion so as to be adjacent to each other in the tire width direction, and tan δ at 60 ° C. of the rubber composition constituting the cap tread rubber layer on the vehicle outer side is determined. The pneumatic tire according to any one of claims 1 to 5, which is higher than tan δ at 60 ° C of a rubber composition constituting a cap tread rubber layer on the vehicle inner side.   The ratio (tan δH / tan δL) of the maximum value tan δH and the minimum value tan δH of tan δ at 60 ° C of the rubber composition constituting the at least two kinds of cap tread rubber layers is in the range of 1.05-1.80. 6. The pneumatic tire according to 6.   The pneumatic tire according to claim 6 or 7, wherein a boundary between the at least two kinds of cap tread rubber layers is arranged under a main groove extending in a tire circumferential direction at a tread portion.   The tread portion is provided with at least one main groove extending in the tire circumferential direction, and the groove area ratio GAo from the tread center to the vehicle outer contact area is greater than the groove area ratio GAi from the tread center to the vehicle inner contact area. The pneumatic tire according to any one of claims 1 to 8, wherein an asymmetric tread pattern that becomes smaller is formed.   The difference between the groove area ratio GAo in the ground contact area outside the vehicle and the groove area ratio GAi in the ground contact area inside the vehicle (GAi−GAo) where the groove area ratio GA in the entire ground contact area is 20% to 40%. The pneumatic tire according to claim 9, wherein the range is 1% to 15%.   The pneumatic tire according to any one of claims 1 to 10, having a tire size with a flatness ratio of 50% or less.   The pneumatic tire according to any one of claims 1 to 10, which is mounted on a vehicle having a camber angle of -0.5 ° to -4.0 °.

Images