Sumitomo Rubber Industries

A pneumatic tire has a profile including a ground contact surface and a first side outer surface. The ground contact surface has a first virtual line inclined at a first angle of 74 to 80 degrees relative to a tire radial direction. The first side outer surface has a second virtual line inclined at a second angle of 36 to 40 degrees relative to the tire radial direction. The tread portion has a belt layer including belt cords arranged therein at an angle λ relative to a tire circumferential direction. A ride comfort index (λ×t/TW) is from 1.0 to 2.0. The ride comfort index is defined by the angle λ in degree, a first distance (t) in millimeter in the tire radial direction from a first ground contact edge to a tire equator on the ground contact surface, and a ground contacting width (TW) in millimeter.

A pneumatic tire (1) includes a first ground contact edge (Te1), a ground contact surface (3a) extending therefrom to a second ground contact edge (Te2), a first side outer surface (6a) extending radially inward therefrom, and a tread portion (3) having a first shoulder land region (5A) demarcated by a first shoulder circumferential groove (4A) and the first ground contact edge. A first virtual line (L1) is a tangent line at an axial midpoint (Pm) of the first shoulder land region inclined at an angle from 74 to 80° and a second virtual line (L2) is a tangent line at a first position (P1) of the first side outer surface inclined at an angle from 36 to 40° relative to the tire radial direction. A radial first distance (t) from the first ground contact edge to the tire equator (C) is 2% to 6% of a ground contacting width (TW).

The present invention provides a tire having both dry grip performance and grip performance on snow improved in a well-balanced manner, and the tire comprises a tread portion (2) and a belt layer (8) provided on an inner side of the tread portion in a tire radial direction, the tread portion is formed from a rubber composition containing styrene-butadiene rubber having a styrene content of 25% by mass or less as a rubber component, the belt layer includes a metal cord as a reinforcing cord, in at least one layer, the metal cords is arranged to form an angle of 30 degrees or more with respect to a tire circumferential direction, and a ratio (St/AG), calculated from a value of the styrene content St (% by mass) of the styrene-butadiene rubber and a value of the angle AG (degrees) formed by the metal cord with respect to the tire circumferential direction, is less than 0.8.

A heavy duty tire 2 includes a tread 4 having one or more center circumferential grooves 16. A center portion 28 of the tread 4 includes center land portions 22 each including lateral grooves 32 arranged in the center portion 28 such that a reference lateral groove and a corresponding lateral groove respectively located on one side and another side in a circumferential direction constitute one lateral groove pair. Second and first ends Es and Ef of the reference lateral groove and the corresponding lateral groove in the lateral groove pair are at the same position in the circumferential direction. The one or more center circumferential grooves 16 include at least one circumferential narrow groove 44 having a pair of wall surfaces 44S that come into contact with each other at a narrow groove portion 48 when the tread 4 comes into contact with a road surface and becomes deformed.

A pneumatic tire 1 includes, on a first side portion 3A, first side blocks 11 arranged on a first tire circumferential line Y1 and second side blocks 12 arranged on a second tire circumferential line Y2. The first side blocks 11 and the second side blocks 12 are spaced apart in a tire circumferential direction, but overlap in tire radial and circumferential directions. An overlapping length Ha in the tire radial direction by which the first side block 11 and the second side block 12 overlap is 30% to 60% of a maximum length H2 in the tire radial direction of the second side block 12. An overlapping length La in the tire circumferential direction by which the first side block 11 and the second side block 12 overlap is 5% or more of a maximum length L2 in the tire circumferential direction of the second side block 12.

A motorcycle tire (1) includes crown blocks (4) including first crown blocks (6) and second crown blocks (7). Each of the first crown blocks (6) has a heel-side edge (11) formed in a V-shape and inclined at an angle (α1) of 10 degrees or less on both axial sides with respect to the tire axial direction. A total number of the first crown blocks (6) is 30% or more of a total number of the crown blocks (4). A first ground contacting surface shape (6a) of each of the first crown blocks (6) has a maximum length (W1) in the tire axial direction from 60% to 70% of a tread width. Each of the second crown blocks (7) has a second ground contacting surface shape (7a) having a maximum length (WC) in the tire axial direction smaller than the maximum length (W1) of the first ground contacting surface shape (6a).

A tire 2 includes a tread 4 and a band 16. The tread 4 has an outer surface 4G including a crown portion 64, a pair of middle portions 66, and a pair of shoulder portions 68. The crown portion 64 has a contour represented by an arc having a radius TR1 not less than 5 times and not greater than 7 times an axial width Wa of a ground-contact surface of the tire 2 in a standard state. The band 16 includes a band cord 56 composed of an organic fiber cord. At a position corresponding to 70% of a maximum width SW of the tire 2 in the standard state, the band cord 56 has a contraction ratio SRs not less than 70% and not greater than 130% of a contraction ratio SRc of the band cord 56 on an equator plane of the tire 2.

Provided is a technique for detecting the rotation of attachment positions of tires in a vehicle. A tire position rotation detection device includes an acquisition unit, a first calculation unit, a second calculation unit, and a rotation determination unit. The acquisition unit acquires a rotational speed of each of tires while a vehicle is traveling. The first calculation unit calculates a first indicator. The second calculation unit calculates a second indicator. The rotation determination unit determines whether or not rotation of attachment positions of the tires has been performed before the vehicle starts traveling based on the first indicator and the second indicator. The rotation determination unit determines that the rotation of the tires has been performed before the vehicle starts traveling when a change in the first indicator from an initial value exceeds a predetermined first threshold value and a change in the second indicator from an initial value is equal to or below a predetermined second threshold value.

Provided is a pneumatic tire comprising a carcass, a reinforcing layer, and a cap tread, wherein the following inequalities are satisfied, (1) A 2 − A 1 > 0 (2) L 1 / L 2 > 0.30 (3) 30 ° CE * c > K / A 2 − A 1 × L 1 − L 2 × 0.3 <img class="EMIRef" id="9a0e1778-f6ea-4b29-9d88-9fa5e978fda3-ia03" /> (where K is 310) where A<1> represents an angle, in degrees, at which a carcass cord inclines from a tire circumferential direction at a position on a tire center line, A<2> represents an angle, in degrees, at which the carcass cord inclines from the tire circumferential direction at a tire maximum width position, L<1> represents a land ratio, in %, of a region including a tire equator, L<2> represents a land ratio, in %, of a pair of regions including tread ends, 30°CE*c represents a complex elastic modulus at 30°C of a rubber composition constituting the cap tread, and K represent a constant.

A tire having a tread portion including circumferential grooves and land regions each provided with groove-shaped portions (31) each having a first end on a first side and a second end on a second side in a tire circumferential direction. In each pair of the groove-shaped portions circumferentially adjacent to each other, the first end of one groove-shaped portion and the second end of the other groove-shaped portion of the pair are formed at the same circumferential position in the same land region or different land regions. In at least one land region in a 70% loaded state, an absolute value of a difference between one of angles θa of both circumferential edges of the at least one land region and an angle θb of one of the groove-shaped portions formed therein with respect to the tire axial direction is 5 degrees or more.