JP2019116172A - Pneumatic tire - Google Patents

Abstract

To provide a pneumatic tire which can improve braking performance and durability of a bead part while improving steering stability by arranging a side reinforcing layer.SOLUTION: A pneumatic tire 1 includes a pair of side reinforcing layers which are arranged so as to extend to an outer side in a tire radial direction adjacently to a tire width direction with respect to a pair of bead fillers. In both of the pair of side reinforcing layers, a reinforcing cord 22 inclines to a tire circumferential direction so that an outer end 22b in the tire radial direction is positioned on a front side of a rotating direction than an inner end 21a of the tire radial direction. Rubber hardness of a rubber layer of a side reinforcing layer on an inner side is lower than rubber hardness of a rubber layer 23 of a side reinforcing layer 21A on an outer side.SELECTED DRAWING: Figure 2A

Description

  The present invention relates to a pneumatic tire.

  Patent Document 1 discloses a pneumatic tire provided with a side reinforcing layer disposed adjacent to the bead filler in the tire width direction and extending outward in the tire radial direction. The side reinforcing layer has a plurality of reinforcing cords aligned and a rubber layer covering these reinforcing cords. The reinforcing cords extend obliquely with respect to the tire radial direction and the tire circumferential direction.

  By providing the side reinforcing layer, mainly, the rigidity in the tire width direction of the sidewall portion is increased. Due to the increase in rigidity in the tire width direction, deformation of the sidewall portion when a force acts in the tire width direction, such as lane change and turning, is suppressed, and steering stability is improved.

Unexamined-Japanese-Patent No. 5-270218

  Pneumatic tires having conventional side reinforcement layers, including those disclosed in Patent Document 1, have room for further improvement in braking performance, durability of bead portions, and turning performance.

  An object of the present invention is to provide a pneumatic tire capable of improving braking performance, durability of a bead portion, and turning performance while providing a side reinforcing layer to improve steering stability.

  According to one aspect of the present invention, a bead core is disposed on a pair of sidewall portions extending inward in the tire radial direction from both ends of the tread portion, and an end portion on the tire radial direction inner side of the pair of sidewall portions; And a pair of bead portions including bead fillers extending outward in the tire radial direction, and adjacent to the bead fillers in the pair of bead portions in the tire width direction and extending outward in the tire radial direction, respectively A pair of side reinforcements, comprising a plurality of arranged and aligned reinforcement cords and a rubber layer covering the plurality of reinforcement cords, the plurality of reinforcement cords being spaced apart in the circumferential direction of the tire A layer, a rotational direction is designated, and a regular wearing in / out of the vehicle is designated, and the pair of side reinforcing layers is Also in the case of misalignment, each of the reinforcing cords is inclined with respect to the tire radial direction so that the outer end in the tire radial direction is positioned on the front side in the rotational direction with respect to the inner end in the tire radial direction. The side reinforcement layer includes an outside side reinforcement layer located outside when the vehicle is properly mounted on the vehicle, and an inside side reinforcement layer located inside when the vehicle is properly mounted on the vehicle, The pneumatic tire is provided, wherein the rubber hardness of the rubber layer of the layer is lower than the rubber hardness of the rubber layer of the outside side reinforcing layer.

  By providing the side reinforcing layer disposed adjacent to the bead filler in the tire width direction and extending outward in the tire radial direction, deformation of the sidewall portion is suppressed. As a result, steering stability is improved.

  In the pair of side reinforcing layers, that is, the out-side side reinforcing layer and the in-side side reinforcing layer, the reinforcing cords are inclined in the same direction with respect to the tire radial direction. That is, in any of the out-side and in-side side reinforcing layers, the reinforcing cords are located in the tire radial direction so that the outer end in the tire radial direction is positioned forward of the inner end in the tire radial direction. It is inclined. Therefore, the direction of the force received by the pneumatic tire from the road surface at the time of braking of the vehicle is not the direction in which the individual reinforcing cords are expanded or contracted, but the reinforcing cords are further inclined in the tire circumferential direction or the reinforcing cords are bent. As a result, the contact length at the time of braking of the vehicle can be extended, and the braking performance is improved.

  Particularly when the pneumatic tire is mounted on a vehicle so as to have a negative camber, the contact pressure on the in side tends to be higher than the contact pressure on the out side. Due to this tendency, the load on the in-side bead portion tends to be higher than the load on the out-side bead portion. By setting the rubber hardness of the in-side side reinforcing layer to be lower than the rubber hardness of the out-side side reinforcing layer, the tire circumferential rigidity of the in-side side reinforcing layer is compared to the tire circumferential rigidity of the out-side side reinforcing layer. Lower. As a result, when the pneumatic tire is mounted on a vehicle so as to have a negative camber, ease of deformation of the in-side bead portion to which a relatively high load is applied is ensured (the deformation is easier than the out-side bead portion) Since the property is high), the bead durability of the inward bead portion is improved.

  When the vehicle turns, the contact pressure on the in side of the pneumatic tire tends to be higher than the contact pressure on the out side. By setting the rubber hardness of the in-side side reinforcing layer to be lower than the rubber hardness of the out-side side reinforcing layer, the tire circumferential rigidity of the in-side side reinforcing layer is compared to the tire circumferential rigidity of the out-side side reinforcing layer. Lower. As a result, at the time of turning of the vehicle, the contact length on the in side where the ground contact pressure is relatively high is secured (the contact length is longer than on the out side), so the turning performance is improved.

  The inclination angle of each of the reinforcement cords with respect to the tire circumferential direction may be set to 15 degrees or more and 45 degrees or less in any of the out-side and in-side side reinforcement layers.

  The inclination angle of the reinforcing cord is defined as an angle (acute angle) formed by the reinforcing cord with respect to a reference line which is tangent to the tire circumferential direction at the tire radial inner end of the reinforcing cord. If the inclination angle of the reinforcing cord is less than 15 degrees, the rigidity in the tire radial direction of the sidewall portion is insufficient, and the steering stability can not be sufficiently improved. When the inclination angle of the reinforcing cord exceeds 45 degrees, the rigidity in the tire radial direction of the sidewall portion becomes excessively high, and the necessary ride comfort can not be obtained.

  The inclination angles of the individual reinforcing cords of the outer side reinforcing layer may be equal to the inclination angles of the individual reinforcing cords of the inner side reinforcing layer.

  By equalizing the inclination angles of the reinforcing cords of the out-side and in-side side reinforcing layers, the contact length is made uniform between the in-side and the out-side at the time of braking of the vehicle, so that the braking performance is further improved.

  The inner end in the tire radial direction of the out side and in side side reinforcing layers is located on the outer side in the tire radial direction from the outer end in the tire radial direction of the bead core, and the tire radial direction of the out side and in side side reinforcing layers The outer end of the tire may be located between the tire radial outer end of the bead filler and the end of the belt disposed in the tread portion.

  The outer ends of the out-side and in-side side reinforcing layers in the tire radial direction may be located inward of the tire maximum width position in the tire radial direction.

  Since the bead core itself is highly rigid, no further rigidity improvement can be expected even if the out-side and in-side side reinforcement layers are arranged adjacent to the bead core in the tire width direction, and only the weight increase is required. It can be invited. Therefore, it is preferable that the tire radial direction inner ends of the out-side and in-side side reinforcing layers be located on the outer side in the tire radial direction from the tire radial direction outer end of the bead core.

  When the outer side and the inner side reinforcing layer are provided up to the region close to the tread portion of the sidewall portion, the deformation of the sidewall portion in the tire width direction is excessively prevented, and the riding comfort may be lowered. The outer ends of the out-side and in-side reinforcing layers are located at the end of the belt disposed in the tread portion, preferably on the inner side in the tire radial direction with respect to the tire maximum width position. Deformation is secured, and the necessary ride comfort can be obtained.

  The thickness of the out side and in side side reinforcing layers may be set to 1.05 mm or more and 1.70 mm or less.

  The reinforcing cord may be a steel cord for any of the outboard and inboard side reinforcing layers.

  According to the pneumatic tire of the present invention, by providing the side reinforcing layer, it is possible to improve the braking performance, the durability of the bead portion, and the turning performance while improving the steering stability.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a meridional cross-sectional view of a pneumatic tire according to an embodiment of the present invention. The side view of the pneumatic tire seen from arrow A 1 of FIG. 1 which penetrates and shows a side reinforcement layer. The side view of the pneumatic tire seen from arrow A 2 of FIG. 1 which penetrates and shows a side reinforcement layer. The elements on larger scale of FIG. 2A. The elements on larger scale of FIG. 2B. BRIEF DESCRIPTION OF THE DRAWINGS The typical partial side view of the pneumatic tire concerning the embodiment of the present invention for explaining the contact length at the time of braking. The typical side view of the pneumatic tire concerning a comparative example for explaining the contact length at the time of braking. The schematic diagram which looked at a pneumatic tire from the vehicle front side for demonstrating a negative camber. The meridian sectional view near a bead part of the pneumatic tire concerning the modification of the present invention.

  Hereinafter, an embodiment according to the present invention will be described according to the attached drawings. The following description is merely illustrative in nature, and is not intended to limit the present invention, its applications, or its applications. In addition, the drawings are schematic, and ratios of respective dimensions and the like are different from actual ones.

  FIG. 1 is a meridional half sectional view of a pneumatic tire 1 according to an embodiment of the present invention, that is, a sectional view in a plane orthogonal to the tire equatorial plane. The rotation direction is designated for the pneumatic tire 1. Further, the pneumatic tire 1 is specified to be properly fitted in and out with respect to a vehicle (not shown). In FIG. 1, arrow B indicates the traveling direction (forward direction) of the pneumatic tire 1 when the pneumatic tire 1 is attached to the vehicle as designated in-out. Further, the rotation direction of the pneumatic tire 1 at the time of forward movement shown by the arrow B is shown by the arrow C in FIG. Furthermore, as shown in FIG. 1, when the pneumatic tire 1 is mounted on a vehicle with specified regular in-out, the side wall portion 3A, the bead portion 4A, the chafer layer 13A, and the side reinforcing layer 21A The sidewall portion 3B, the bead portion 4B, the chafer layer 13B, and the side reinforcing layer 21B are positioned inward with respect to the vehicle.

  The pneumatic tire 1 includes a tread portion 2, a pair of sidewall portions 3A and 3B extending inward in the tire radial direction from both ends of the tread portion 2 in the tire width direction, and tire diameters of the pair of sidewall portions 3A and 3B. It has a pair of bead portions 4A and 4B respectively disposed at the end portions in the inside of the direction.

  A toroidal carcass ply 5 is disposed between the pair of bead portions 4A and 4B on the inner side in the tire radial direction of the tread portion 2 and the sidewall portions 3A and 3B. An inner liner 6 is disposed on the inner side in the tire radial direction of the carcass ply 5. In the tread portion 2, a plurality of belt layers 7 and a belt reinforcing layer 8 (belts) are provided on the outer side in the tire radial direction of the carcass ply 5.

  Each of the bead portions 4A and 4B includes a bead core 11 and a bead filler 12 made of rubber continuous with the bead core 11 and extending outward in the tire radial direction. The bead core 11 is formed by bundling a plurality of bead wires into an annular shape. An annular bead filler 12 having a substantially triangular sectional shape is disposed along the outer end surface (outer end) 11 a of the bead core 11 in the tire radial direction.

  Chafer layers 13A and 13B are disposed around the bead portions 4A and 4B. The chafer layers 13A and 13B are disposed adjacent to the outer surface side of the carcass ply 5 (opposite to the bead portions 4A and 4B), and along with the carcass ply 5, in the tire width direction around the bead portions 4A and 4B. It is folded back from the inside to the outside in the radial direction of the tire.

  Further, in the bead portions 4A and 4B, the side reinforcing layers 21A and 21B are disposed between the rolled up portion of the carcass ply 5 and the bead filler 12. Hereinafter, when the pneumatic tire 1 is properly attached to the vehicle in the specified in-out as shown in FIG. 1, the side reinforcing layer 21A located on the out side with respect to the vehicle is referred to as the outside side reinforcing layer 21A. The side reinforcing layer 21B located inward with respect to the vehicle will be referred to as the in-side side reinforcing layer 21B.

  With reference to FIGS. 2A and 2B together, the respective out-side and in-side side reinforcing layers 21A and 21B are in the form of a substantially annular band when viewed in the tire width direction. In addition, the respective out-side and in-side side reinforcing layers 21A and 21B have a plurality of aligned reinforcing cords 22 and a rubber layer 23 covering the plurality of reinforcing cords 22. In the present embodiment, the reinforcing cords 22 are steel cords. The reinforcing cords 22 may be resin cords such as aramid cords, as long as necessary properties including tensile strength can be obtained.

  Referring to FIG. 1, in the present embodiment, the outside side reinforcing layer 21 </ b> A and the inside side reinforcing layer 21 </ b> B have the same widths WS <b> 1 and WS <b> 2. Further, in the present embodiment, the position P1 in the radial direction of the inner end 21a in the tire radial direction and the position P2 of the outer end 21b in the tire radial direction of the outer side reinforcement layer 21A and the inner side reinforcement layer 21B are also the same. It is.

  The inner ends 21a (position P1) of the out-side and in-side side reinforcing layers 21A and 21B are located outside the tire radial direction end face 21b (position P3) of the bead core 11 in the tire radial direction. The outer end 21b (position P2) in the tire radial direction of the out-side and in-side side reinforcing layers 21A and 21B is the tire width in the tire radial direction of the bead filler 12 and the tire width of the belt reinforcing layer 8 It is located between the direction outer end 8a. In this embodiment, the outer end 21b (position P2) in the tire radial direction of the out-side and in-side side reinforcing layers 21A and 21B is the outer end 12a (position P4) in the tire radial direction of the bead filler 12 and the carcass plus 5 It is located between the end 5a (position P5) of the rolled up portion. More specifically, the outer end 21b (position P2) in the tire radial direction of the out-side and in-side side reinforcing layers 21A and 21B is located more inward in the tire radial direction than the tire maximum width position P6.

  In the present embodiment, the thicknesses of the out-side and in-side side reinforcing layers 21A and 21B are the same, and are set in the range of 1.05 mm to 1.70 mm.

  In the present embodiment, the plurality of reinforcing cords 22 are arranged at intervals in the tire circumferential direction for any of the outside side reinforcing layer 21A and the inside side reinforcing layer 21B. Further, in the present embodiment, each of the reinforcing cords 22 is linear as viewed from the tire width direction in any of the outside side reinforcing layer 21A and the inside side reinforcing layer 21B. Furthermore, each of the reinforcing cords 22 extends in a direction that does not correspond to either the tire circumferential direction or the tire radial direction in any of the outside side reinforcement layer 21A and the inside side reinforcement layer 21B. That is, each of the reinforcing cords 22 is inclined with respect to both the tire circumferential direction and the tire radial direction in any of the out-side side reinforcing layer 21A and the in-side side reinforcing layer 21B. The reinforcing cords 22 are not limited to linear shapes, and may be curved or bent.

  The reinforcing cords 22 are inclined in the same direction with respect to the tire circumferential direction in the out-side side reinforcing layer 21A and the in-side side reinforcing layer 21B. The inclination of the reinforcing cord 22 will be described in detail.

  Referring to FIGS. 2A and 3A, in the outer side reinforcing layer 21A, in the reinforcing cords 22 of the individual reinforcing cords 22, the outer end 22b is closer to the rotational direction C of the pneumatic tire 1 than the inner end 22a in the tire radial direction The vehicle is inclined with respect to the tire circumferential direction and the tire radial direction so as to be located on the front side of the rotation direction when moving forward as shown by arrow B in FIG. Similarly, with reference to FIGS. 2B and 3B, in the outer side reinforcing layer 21A, each reinforcing cord 22 has an outer end 22b ahead of the inner end 22a in the tire radial direction and a front in a rotational direction C of the pneumatic tire 1. It is inclined with respect to the tire circumferential direction and the tire radial direction so as to be located on the side.

  Referring to FIGS. 3A and 3B, in the present embodiment, the inclination angle θa of the reinforcing cords 22 of the outer side reinforcing layer 21A with respect to the tire circumferential direction and the inclination of the reinforcing cords 22 with the inward side reinforcing layer 21B with respect to the tire peripheral direction. The angle θb is set to be the same. The inclination angles θa and θb are defined as angles (acute angles) formed by the reinforcing cord 22 with respect to a reference line SL which is a tangent to the tire circumferential direction at the inner end 22a of the reinforcing cord 22 in the tire radial direction.

  In the present embodiment, the inclination angle θa of the reinforcing cord 22 in the outside side reinforcing layer 21A and the inclination angle θb of the reinforcing cord 22 in the in side side reinforcing layer 21B are both set to 15 degrees or more and 45 degrees or less There is.

  In the present embodiment, among the characteristics affecting the tire circumferential rigidity of the out-side and in-side side reinforcing layers 21A and 21B, the characteristics excluding the rubber hardness of the rubber layer 23 are the outside side reinforcing layer 21A and the inside side reinforcement. The same setting is made in the layer 21B. Thus, the characteristics set identically are the material of the reinforcing cord 22 described above, the inclination angles θa and θb, the widths WS1 and WS2 of the out-side and in-side side reinforcing layers 21A and 21B, and the out-side and in-side side. In addition to the thickness of the reinforcing layers 21A and 21B, the diameter (cord diameter) of the reinforcing cord 22 and the number of ends are included.

  In the present embodiment, the rubber hardness of the rubber layer 23 of the in-side side reinforcing layer 21B is set to be lower than the rubber hardness of the rubber layer 23 of the outside-side side reinforcing layer 21A, thereby the tire circumference of the in-side side reinforcing layer 21A. The directional rigidity is set to be lower than the circumferential rigidity of the outer side reinforcing layer 21A. Specifically, while the durometer hardness specified in JIS K6253-1-2012 is set to 55 or more and 75 or less in the rubber layer 23 of the in-side side reinforcing layer 21B, the outside side reinforcing layer 21A is The rubber layer 23 is set to 65 or more and 85 or less.

  Various features of the pneumatic tire 1 according to the present embodiment having the above configuration will be described.

  By providing out-side and in-side side reinforcing layers 21A and 21B disposed adjacent to the bead filler 12 of the pair of bead portions 4A and 4B in the tire width direction and extending outward in the tire radial direction, sidewall walls are provided. The deformation of the portions 3A and 3B is suppressed. As a result, steering stability is improved.

  Referring to FIGS. 2A to 3B, as described above, the reinforcing cords 22 have the same direction in the tire radial direction and the tire circumferential direction for both the outside side reinforcement layer 21A and the in-side side reinforcement layer 21B. That is, the outer end 22b in the tire radial direction is inclined in a direction located on the front side in the rotational direction C with respect to the inner end 22a in the tire radial direction (inclination angles θa and θb). The setting of the inclination of the reinforcing cords 22 of the out-side and in-side side reinforcing layers 21A and 21B improves the braking performance. Hereinafter, this point will be described in detail.

  Referring to FIG. 4, the force Fa received by the pneumatic tire 1 from the road surface during braking of the vehicle is a force Fb upward in the vertical direction derived from the weight of the vehicle and the pneumatic tire 1 itself, the tread portion 2 and the road surface G. It can be regarded as a resultant force of force Fc that is opposite to the traveling direction of the vehicle in the horizontal direction derived from the friction force between them. When the inclinations of the reinforcing cords 22 of the out side and in side side reinforcing layers 21A and 21B are set as in the present embodiment, the direction of the force Fa received by the pneumatic tire 1 from the road surface G The circumferential direction is further inclined, or the reinforcing cord 22 is bent. Therefore, the dimension (contact length L) in the vehicle traveling direction of the ground contact shape CC of the pneumatic tire 1 becomes significantly longer during braking (indicated by a solid line) as compared with that during normal travel (indicated by a broken line). The braking performance is improved by significantly extending the contact length L at the time of braking of the vehicle.

  In the comparative example shown in FIG. 5, the inclination of the reinforcing cords 22 of the out-side and in-side side reinforcing layers 21A and 21B with respect to the tire radial direction and the tire circumferential direction is opposite to that in the present embodiment. That is, in the comparative example of FIG. 5, the reinforcing cords 22 of the out-side and in-side side reinforcing layers 21A and 21B have the outer end 22b in the tire radial direction on the rear side in the rotational direction C than the inner end 22a in the tire radial direction. It inclines to the direction to be located. When the inclinations of the reinforcing cords 22 of the out-side and in-side reinforcing layers 21A and 21B are thus set, the direction of the force Fa received by the pneumatic tire 1 from the road surface G causes the individual reinforcing cords 22 to expand and contract. It becomes the direction. As a result, unlike the present embodiment, the contact length L is not so long during braking (indicated by a solid line) as compared with that during normal travel (indicated by a broken line), and braking performance is inferior to that of the present embodiment. .

  Further, in the present embodiment, when the inclination angles θa and θb of the reinforcing cords 22 of the out-side and in-side side reinforcing layers 21A and 21B are equal, the ground contact length L is made uniform between the in and out sides at the time of braking of the vehicle. This also improves the braking performance.

  If the inclination angles θa and θb of the reinforcing cords 22 of the out-side and in-side side reinforcing layers 21A and 21B are smaller than 15 degrees, the rigidity in the tire radial direction of the sidewall portions 3A and 3B is insufficient, and steering stability is sufficient. It can not be improved. If the inclination angles θa and θb of the reinforcing cords 22 exceed 45 degrees, the rigidity in the tire radial direction of the sidewall portions 3A and 3B becomes excessively high, and the necessary ride comfort can not be obtained. Therefore, as described above, the inclination angles θa and θb of the reinforcing cords 22 of the out-side and in-side side reinforcing layers 21A and 21B are preferably 15 degrees or more and 45 degrees or less.

  Referring to FIG. 6, particularly when the pneumatic tire 1 is mounted on a vehicle so as to have the negative camber NC, the contact pressure on the in side tends to be higher than the contact pressure on the out side. Due to this tendency, the load on the in-side bead portion 4B tends to be higher than the load on the out-side bead portion 4A. By setting the rubber hardness of the in-side side reinforcing layer 21B to be lower than the rubber hardness of the out-side side reinforcing layer 21A, the tire circumferential rigidity of the in-side side reinforcing layer 21B is equal to the tire circumferential direction of the out-side side reinforcing layer 21A. It is lower than the stiffness. As a result, when the pneumatic tire 1 is mounted on a vehicle so as to have the negative camber NC, the deformability of the in-side bead portion 4B to which a relatively high load is applied is ensured (from the out-side bead portion) Also, since the ease of deformation is high), the bead durability of the in-side bead portion 4B is improved.

  When the vehicle turns, the contact pressure on the in side of the pneumatic tire 1 tends to be higher than the contact pressure on the out side. By setting the rubber hardness of the in-side side reinforcing layer 21B to be lower than the rubber hardness of the out-side side reinforcing layer 21A, the tire circumferential rigidity of the in-side side reinforcing layer 21B is equal to the tire circumferential direction of the out-side side reinforcing layer 21A. It is lower than the stiffness. As a result, at the time of turning of the vehicle, the contact length on the in side where the ground contact pressure is relatively high is secured (the contact length is longer than on the out side), so the turning performance is improved.

  As described above, according to the pneumatic tire 1 according to the present embodiment, the braking performance and the durability of the bead portion 4B are improved while the steering stability is improved by providing the out-side and in-side side reinforcing layers 21A and 21B. , And the turning performance can be improved.

  Since the bead core 11 itself has high rigidity, even if the out-side and in-side side reinforcing layers 21A and 21B are disposed adjacent to the bead core 11 in the tire width direction, no further improvement in rigidity can be expected. , Can only lead to weight gain. Therefore, as in the present embodiment, the inner end 21a of the out-side and in-side side reinforcing layers 21A and 21B in the tire radial direction is the outer end of the bead core 11 in the tire radial direction, that is, the outer side of the end surface 11a in the tire radial direction. It is preferred to be located in

  When the out side and in side side reinforcing layers 21A and 21B are provided up to the region close to the tread portion 2 of the side wall portions 3A and 3B, the deformation of the side wall portion 3 in the tire width direction is excessively impeded and the ride comfort Sex may be reduced. As in the present embodiment, the outer end 21b of the out-side and in-side side reinforcing layers 21A and 21B is preferably the tire at the tire width direction outer end 8a of the belt reinforcing layer 8, preferably at the tire maximum width position P6. By being located inside in the radial direction, the deformability of the sidewall portions 3A, 3B in the tire width direction is secured, and the necessary riding performance can be obtained.

  The pneumatic tire 1 according to the modification shown in FIG. 7 has a side reinforcing layer 21A, which is disposed between the rolled up portion of the carcass ply 5 and the bead filler 12, that is, on the outer side in the tire width direction with respect to the bead filler 12. In addition to 21B, side reinforcement layers 21A 'and 21B' disposed on the inner side in the tire width direction with respect to the bead filler 12 are provided. Only the side reinforcing layers 21A and 21B disposed on the inner side in the tire width direction with respect to the bead filler 12 may be provided, and the side reinforcing layers 21A and 21B disposed on the outer side in the tire width direction with respect to the bead filler 12 may be eliminated.

Reference Signs List 1 pneumatic tire 2 tread portion 3A, 3B sidewall portion 4A, 4B bead portion 5 carcass ply 5a end portion 6 inner liner 7 belt layer 8 belt reinforcing layer 8a end portion 11 bead core 11a end surface (outer end)
12 bead filler 12a outer end 13A, 13B chafer layer 21A, 21B, 21A ', 21B' side reinforcing layer 21a inner end 21b outer end 22 reinforcing cord 22a inner end 22b outer end 23 rubber layer A1, A2 side view direction B Forward direction C Rotation direction WS1, WS2 Width of side reinforcement layer P1 Position of inner end of side reinforcement layer P2 Position of outer end of side reinforcement layer P3 Position of end face of bead core P5 Position of end of carcass ply P6 Tire maximum width position θa, θb Inclination angle SL Reference line Fa, Fb, Fc Force G Road surface CC Grounding shape L Grounding length NC Negative camber

Claims (7)

A pair of sidewall portions extending respectively inward in the tire radial direction from both ends of the tread portion;
A pair of bead portions, each disposed at a tire radial direction inner end portion of the pair of sidewall portions, and including a bead core, and a bead filler extending to the tire radial direction outer side continuously with the bead core;
With respect to the bead fillers of the pair of bead portions, a plurality of reinforcing cords arranged and aligned so as to be adjacent in the tire width direction and extend outward in the tire radial direction, and covering the plurality of reinforcing cords And a pair of side reinforcing layers spaced apart in the circumferential direction of the tire.
The rotation direction is specified,
The regular wearing in and out of the vehicle is specified.
In each of the pair of side reinforcing layers, each of the reinforcing cords is located in the tire radial direction such that the outer end in the tire radial direction is positioned on the front side in the rotational direction with respect to the inner end in the tire radial direction Inclined and
The pair of side reinforcement layers includes an outside side reinforcement layer positioned outside when the vehicle is properly mounted on the vehicle, and an inside side reinforcement layer positioned when the vehicle is properly mounted on the vehicle.
The pneumatic tire according to claim 1, wherein a rubber hardness of the rubber layer of the inner side reinforcing layer is lower than a rubber hardness of the rubber layer of the outer side reinforcing layer.   The pneumatic tire according to claim 1, wherein an inclination angle of each of the reinforcement cords with respect to the tire circumferential direction is 15 degrees or more and 45 degrees or less in any of the out-side and in-side side reinforcement layers.   The pneumatic tire according to claim 2, wherein the inclination angles of the individual reinforcing cords of the outer side reinforcing layer and the inclination angles of the individual reinforcing cords of the inner side reinforcing layer are equal. An inner end in a tire radial direction of the out-side and in-side side reinforcing layers is located on the outer side in the tire radial direction from an outer end of the bead core in the tire radial direction,
The tire radial direction outer ends of the outside and inside side reinforcing layers are located between the tire radial direction outer ends of the bead fillers and the ends of the belts disposed in the tread portion. The pneumatic tire according to any one of claims 1 to 3.   The pneumatic tire according to claim 4, wherein outer ends in the tire radial direction of the out-side and in-side side reinforcing layers are positioned inside the tire radial direction with respect to a tire maximum width position.   The pneumatic tire according to any one of claims 1 to 5, wherein a thickness of the out-side and in-side side reinforcing layers is 1.05 mm or more and 1.70 mm or less.   The pneumatic tire according to any one of claims 1 to 6, wherein the reinforcing cord is a steel cord in any of the outboard side and the inside side reinforcing layer.

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