Patent classifications
B60C2011/0348
Heavy Duty Pneumatic Tire
A pneumatic tire with improved heat build-up resistance in a land portion in a tread center region. The pneumatic tire is provided with a tread pattern that includes a plurality of center lug grooves (14) disposed at intervals in a tire circumferential direction that cross a tire equator line; a plurality of shoulder lug grooves (12A, 12B) disposed in intervals between the plurality of center lug grooves in the tire circumferential direction extending outward in the tire width direction, an inner end in the tire width direction being disposed outward of an end of the center lug groove in the tire width direction; a pair of circumferential primary grooves (11A, 11B) extending around an entire circumference of the pneumatic tire in a wave-like shape with the ends of the center lug grooves and the inner ends of the plurality of shoulder lug grooves in the tire width direction alternately connecting to the pair of circumferential primary grooves (11A, 11B); and a circumferential secondary groove (10) disposed on the tire equator line around the entire circumference of the pneumatic tire that intersects the center lug grooves.
A straight line that joins an intersection portion between the center lug groove and the circumferential secondary groove and the end of the center lug groove has an inclination angle with respect to the tire circumferential direction ranging from 55° to 75°.
Tire
In a tire, plural outer side cutouts, which respectively correspond to block land portions and extend toward tire width direction outer sides and end midway along outer side land portions, are formed so as to be spaced apart in a tire circumferential direction in tire width direction inner-side side walls, which are exposed to central circumferential grooves, of the outer side land portions that are provided further toward tire width direction outer sides than the two central circumferential grooves respectively. Further, at least portions of tire width direction inner side openings of the outer side cutouts are positioned between maximum position A, at which a tire width direction distance of a corresponding block land portion is a maximum, and an intermediate point B of two vertices that are adjacent at a tire width direction outer-side side wall of the block land portion.
Pneumatic tire
A pneumatic tire includes circumferential grooves aligned in a lateral direction and extending in a circumferential direction, lateral grooves aligned in the circumferential direction and extending to cross the circumferential direction, communicating at ends with the circumferential grooves and defining a block-shaped land portion between the circumferential grooves, two narrow grooves aligned in the lateral direction and extending in the circumferential direction, communicating at ends with a lateral groove and dividing the land portion defined by each of the circumferential grooves and each of the lateral grooves into small land portions, the narrow grooves having a smaller groove width than the circumferential grooves and being formed with a bent portion in an intermediate portion, the bent portion being disposed inward in the lateral direction, and bend points of the bent portions being disposed at positions offset from one another in the circumferential direction.
Pneumatic tire
A pneumatic tire includes first and second main grooves, and first sipes and auxiliary grooves on second land portions between the first and second main grooves, the auxiliary grooves opening to the second main grooves and terminating in the second land portions. The auxiliary grooves bend at a bend point and include a first portion extending from an opening end to the bend point, and a second portion extending from the bend point to a terminating end. A groove width of the first portion gradually reduces from the opening end to the bend point. Second sipes have an end that opens to each of the second main grooves and another end that opens to each of the terminating ends. Third sipes have an end that opens to the first main grooves and another end that opens to the first portions. The sipes are parallel to each other.
Pneumatic tire
A center rib is formed by two circumferential main grooves. A main inclined groove and an auxiliary inclined groove are formed in the center rib. The main inclined groove is inclined with respect to the tire circumferential direction to become distanced from the tire equatorial plane from a leading side toward a trailing side in a tire rotational direction, a plurality of the main inclined grooves being juxtaposed in the tire circumferential direction and disposed alternately in the tire circumferential direction on both sides of the tire equatorial plane. The auxiliary inclined groove inclines with respect to the tire circumferential direction to become distanced from the tire equatorial plane from the leading side toward the trailing side in the tire rotational direction, a leading end and a trailing end terminating within the center rib while intersecting at least two of the main inclined grooves.
PNEUMATIC TIRE
A pneumatic tire includes a tread having a shoulder main groove, and a center main groove such that the tread is divided into a shoulder land portion and a middle land portion between the shoulder main groove and center main groove. The shoulder and center main grooves are formed such that a ratio W1/W2 of a tire axial direction width W1 of the shoulder land portion to a tire axial direction width W2 of the middle land portion is in range of 6 to 2.4. The shoulder land portion has a shoulder narrow groove formed on a shoulder main groove side and continuously extending in the tire circumferential direction such that the shoulder narrow groove has groove width smaller than groove width of the shoulder main groove, and the tread is formed such that a first camber amount is in range of 5.3% to 6.5% of tread ground contact width.
Pneumatic tire
A pneumatic tire is provided in the tread portion with a central land portion between two crown main grooves. The central land portion is provided with notches each having a depth of 55% to 65% of the depth of the crown main groove and having a closed end and an open end opening to the crown main groove. The maximum axial length of the central notch is 10% to 15% of the maximum axial length of the central land portion, and the circumferential length of the opening is 10% to 15% of one circumferential pitch of the shoulder block row 7R. The circumferential length of the opening is 15% to 25% of one circumferential pitch of the central notches.
PNEUMATIC TIRE
The disclosed pneumatic tire includes a plurality of circumferential main grooves and is configured to be mounted in a specified vehicle mounting direction. On the tread surface, an inner shoulder land portion does not substantially include a groove, and has only one or more inner circumferential sipe extending in the tread circumferential direction and a plurality of inner widthwise sipes extending in the tread width direction, and an outer shoulder land portion has a plurality of widthwise grooves communicating with the circumferential main groove and the tread edge and extending in the tread width direction and an outer widthwise sipe located between the widthwise grooves adjacent in the tread circumferential direction and extending in the tread width direction.
Pneumatic tire
A shoulder land portion includes a main body land portion formed between a thin groove extending in a tire circumferential direction on a tire width direction inner side of a ground contact end and a shoulder main groove, and the main body land portion includes a contact region adjacent to the shoulder main groove provided along the tire circumferential direction and a non-contact region provided along the tire circumferential direction between the thin groove and the contact region. The contact region contacts a road surface in a normal load state, and the non-contact region is recessed to a tire radial direction inner side from a tread surface. The non-contact region does not contact the road surface in the normal road state, and when a length of the non-contact region is W1 and a length of the main body land portion both along the tire width direction is Rw, 0.2Rw≤W1≤0.5Rw.
Pneumatic Tire
In a pneumatic tire, among land portions located on both sides of a center circumferential main groove, a first land portion includes a first circumferential narrow groove, and a second land portion includes a second circumferential narrow groove; among regions defined by the first circumferential narrow groove in the first land portion, a side adjacent to the center circumferential main groove is defined as a first-land-portion first region, and the other side is defined as a first-land-portion second region; among regions defined by the second circumferential narrow groove in the second land portion, a side adjacent to the center circumferential main groove is defined as a second-land-portion first region, and the other side is defined as a second-land-portion second region; the first-land-portion first region and the second-land-portion first region have plane regions; and lateral grooves are formed in the first-land-portion second region and the second-land-portion second region.