Pneumatic tire

摘要

Provided is a pneumatic tire improved in on-ice friction properties of the tire, which is excellent in on-ice performance, in particular, on-ice braking performance. The pneumatic tire according to the present invention includes, in a tread portion surface located between both tread ends, a plurality of main grooves extending in a tire circumferential direction; a plurality of lateral grooves extending in a tire width direction, the lateral grooves each having one bent point so as to be in a convex shape in the tire circumferential direction between the main grooves and/or between the main groove and the tread end, the plurality of main grooves and the plurality of lateral grooves partition-forming a plurality of blocks each including a circumferential protrusion in a shape conforming to the convex shape of the lateral groove, the blocks each including at least one lateral sipe extending in the tire width direction in a shape conforming to the lateral grooves, in which the lateral sipe is equal in tire-width-direction dimension to the block having the lateral sipe disposed therein when both are projected onto the same plane which includes the tire rotation axis and is perpendicular to the block surface.

主权项

1. A pneumatic tire comprising , at least in part of a tread portion surface located between both tread ends:
a plurality of main grooves extending in a tire circumferential direction; and a plurality of lateral grooves extending in a tire width direction, the lateral grooves each having one bent point so as to be in a convex shape in the tire circumferential direction between the main grooves and/or between one of the main grooves and a tread end, the plurality of main grooves and the plurality of lateral grooves partition-forming a plurality of blocks each having a circumferential protrusion in a shape conforming to the convex shape of the lateral groove, the lateral grooves including a first lateral groove portion and a second lateral groove portion, the first lateral groove portion extending from the apex of the circumferential protrusion to one of the main grooves or the tread end, the second lateral groove portion extending from the apex of the circumferential protrusion to another main groove or the tread end, the blocks each having at least one pair of lateral sipes extending in the tire width direction in a shape conforming to the lateral grooves, the pair of lateral sipes includes a first sipe and a second sipe, the first sipe having one end thereof opened to one of the main grooves or to the tread end in the tire width direction and the other end thereof terminated within the block or opened to a lateral groove, the second sipe having one end thereof opened to another main groove located on an opposite side of the block from the main groove in the width direction or the tread end and the other end thereof terminated within the block or opened to a lateral groove, wherein the total length of the pair of lateral sipes is equal in tire-width-direction dimension to the block having the lateral sipe disposed therein when both are projected onto the same plane which includes the tire rotation axis and is perpendicular to the block surface, wherein the first sipe extends along the first lateral groove and the second sipe extends along the second lateral groove, the first sipe and the second sipe being non-parallel with each other, wherein the first sipe has a tire-width-dimensional component overlapping with a tire-width-dimensional component of the second sipe in an area where the apex is located in the tire width direction, in a projection view obtained by projecting the first sipe and the second sipe onto the same plane which includes the tire rotation axis and is perpendicular to the block surface, wherein the block has at least three lateral sipes formed therein, and at least one of the lateral sipes located between lateral sipes located on both ends of the block in the tire circumferential direction is formed as a bottom-enlarged sipe having an enlarged portion at the bottom thereof, and wherein the lateral sipes located on both ends of the block in the circumferential direction are not bottom-enlarged sipes.