The Yokohama Rubber Co., Ltd.

Sony Corporation

Tamron Company, Ltd.

Kenichi Matsumoto

Kenichi Sato

Junichiro Misawa

Hidekazu Kamon

Sumio Otsuka

Masaaki Kamoda

Toshimitsu Iwai

Kenji Ishimatsu

Kikuo Kotake

A tread pattern of a tire includes: a circumferential main groove extending in a tire circumferential direction; a plurality of sipes extending in a tire width direction within a region of a land portion in contact in the tire width direction with the circumferential main groove; and a chamfered surface having a tread surface of the land portion inclined toward the circumferential main groove in an end portion in the tire width direction on a circumferential main groove side of the land portion, the chamfered surface being provided in a plurality in the tire circumferential direction, and the sipes opening to the plurality of the chamfered surfaces without reaching a groove wall of the circumferential main groove. The length of the chamfered surface in the tire circumferential direction is greater than the length thereof in the tire width direction.

Tire

A tire tread includes a pair of first circumferential main grooves in a first half-tread region on one side in a tire width direction, a pair of second circumferential main grooves in a second half-tread region, first sipes provided in a first region between the first circumferential main grooves, a circumferential narrow groove having a groove width smaller than a groove width of the first circumferential main groove and extending in the tire circumferential direction within the first region, and sipes in a second region between the second circumferential main grooves, extending in the tire width direction, and closing within the second region. The number of intervals of the second sipes mutually adjacent is larger than the number of intervals of the first sipes mutually adjacent.

A tire tread pattern includes: first sipes in a first land portion between first and second circumferential main grooves; first chamfered surfaces in which a tread surface of the first land portion is inclined toward a first circumferential main groove side in an end portion in a width direction, the first sipes opening to the first chamfered surfaces; second sipes in a second land portion on an opposite side of the first land portion with respect to the second circumferential main groove; and second chamfered surfaces in which a tread surface of the second land portion is inclined toward a second circumferential main groove side in an end portion in the width direction, the second sipes opening to the second chamfered surfaces. The first and second chamfered surfaces are greater in length in the circumferential direction than in the width direction.

A tread pattern of a pneumatic tire includes a pair of circumferential grooves and a plurality of siped lug grooves extending in a tire width direction between the pair of circumferential grooves and disposed at intervals in the tire circumferential direction. Each of the siped lug grooves includes a lug groove extending from a first circumferential groove of the pair of circumferential grooves and closed, and a sipe extending from a closed end of the lug groove toward a second circumferential groove and connected to the second circumferential groove. The plurality of siped lug grooves include at least one first siped lug groove extending while bending with an extension direction of the lug groove differing from an extension direction of the sipe, and at least one second siped lug groove extending linearly with the extension direction of the lug groove aligning with the extension direction of the sipe.

Pneumatic tire

In a tread pattern of a tire, a main groove side of a shoulder lug groove in a side of a first circumferential main groove inclines with respect to the width direction. In each of first intermediate lug grooves and inner lug grooves, a direction from one side toward the other side in the width direction is inclined to a side identical to a side to which the main groove side is inclined. The first intermediate lug grooves overlap with extension lines of each of the shoulder lug grooves extending from a closed end of each of the shoulder lug grooves along an inclination direction of the main groove side toward each of closed ends of the inner lug grooves. A second intermediate lug groove extends between two of the extension lines adjacent in the circumferential direction, in a direction along the extension lines.

A tread pattern of a pneumatic tire includes: first and second circumferential main grooves; a first circumferential narrow groove between the first and second circumferential main grooves, the first circumferential narrow groove having a narrower width than the first and second circumferential main grooves; an intermediate lug groove extending from the second circumferential main groove toward the first circumferential narrow groove, the intermediate lug groove being closed without reaching the first circumferential narrow groove; and a sipe extending from the closed end of the intermediate lug groove to connect the closed end with the first circumferential narrow groove. No lug grooves are between the first circumferential main groove and the first circumferential narrow groove, and a groove wall of the first circumferential main groove on a side of the first circumferential narrow groove circumnavigates without interruption in the tire circumferential direction.

A tire mold comprises sector molds for forming a tread portion of a tire and mold pins provided on the sector molds for forming insertion holes in the tread portion. The insertion holes each comprise a first hole portion with a first inner diameter where a body portion of a stud pin is disposed and a second hole portion with a second inner diameter greater than the first inner diameter where a bottom flange portion of the stud pin is disposed. The mold pins each comprise a trunk portion with a first outer diameter for forming the first hole portion and a tip portion with a second outer diameter greater than the first outer diameter for forming the second hole portion.

Tire mold and pneumatic tire

Automobile tire

A stud pin for mounting in a pneumatic tire includes a tip including a tip end surface configured to come into contact with a road surface, and a body portion configured to house the tip. An end surface of the tip configured to come into contact with a road surface comprises an axis of symmetry which defines a line symmetrical shape of the end surface; a centroid of a shape of the end surface offset to a first side in an axial direction from a center position of a range the end surface covers in the axial direction of the axis of symmetry; and a recessed portion recessed inward of the end surface, the recessed portion being provided on, of peripheries of the end surface, a periphery of the end surface running between a first most distal end portion and a second most distal end portion.

Pneumatic tire and stud pin

A stud pin includes a tip and a body portion provided around a center axis of the stud pin. The body portion includes an upper flange, a lower flange, and a shank portion connecting the upper flange and the lower flange. A first side surface of the lower flange includes a first curved surface recessed inward in relation to the body portion. A second side surface of the upper flange includes a second curved surface bulging toward a periphery of the body portion, and a pair of flat surfaces configured to connect the second curved surface to interpose the second curved surface. A trough portion where the first curved surface is most recessed and a peak portion where the second curved surface is most bulged are located at an identical orientation position about the center axis as viewed from the axial direction.

Stud pin and studded tire

A stud pin and a pneumatic tire are provided. A tip portion of the stud pin includes an end surface with a concave polygonal profile shape including one recessed portion and one protrusion portion on a side opposite the recessed portion. The stud pin is mounted in a stud pin installation hole with the protrusion portion facing a leading side in a tire circumferential direction and the recessed portion face a trailing side.

Stud pin and pneumatic tire

A stud pin includes a tip including a tip end surface configured to come into contact with a road surface and a trunk portion that supports the tip and extends in one direction. The trunk portion includes an upper flange disposed at a first end of the trunk portion, the tip being fixed to the upper flange, and a lower flange disposed at a position to a side opposite the upper flange of the trunk portion. An upper end surface of the upper flange from which the tip protrudes includes a recessed surface, the recessed surface including a smooth inclined surface recessing in a curved manner or a linear manner toward the lower flange with advancement toward a protruding base portion of the tip.

Stud pin, and pneumatic tire

A stud pin includes a buried base portion embedded in a tread portion of a pneumatic tire and a tip portion protruding from the road contact surface of the tread portion when the buried base portion is embedded in the tread portion. A tip surface of the tip portion includes: a first protrusion portion and a second protrusion portion longer in the tire width direction than in the tire circumferential direction and protruding toward one side in the tire circumferential direction; a first recessed portion disposed between the first and second protrusion portions and recessed toward the other side in the tire circumferential direction; a third protrusion portion and a fourth protrusion portion protruding toward the other side in the tire circumferential direction; and a second recessed portion disposed between the third and fourth protrusion portions and recessed toward the one side in the tire circumferential direction.

Growing community of inventors

Hiratsuka, Japan

Kenichi Matsumoto