Heavy duty tire

摘要

A heavy duty tire comprises a tread portion provided with a central circumferential groove, a crown circumferential groove on each side thereof and crown axial grooves extending therebetween so as to for crown blocks. The crown block is circumferentially subdivides into two block pieces by a crown narrow groove. The crown axial groove is provided in the groove bottom with a tie bar rising therefrom and connecting the circumferentially adjacent two crown blocks each other. The crown axial grooves are inclined at an angle α of from 10 to 30 degrees with respect to the tire axial direction.;The central circumferential groove and an axially inner part of the crown axial groove which part is axially inside the tie bar, are shallower than the crown circumferential groove.

主权项

1. A heavy duty tire comprising
a tread portion provided with a central circumferential groove disposed along the tire equator, a crown circumferential groove disposed on each side of the central circumferential groove, and a plurality of crown axial grooves disposed on each side of the central circumferential groove and extending axially from the central circumferential groove to said crown circumferential grooves so that portions between the central circumferential groove and the crown circumferential groove are circumferentially divided into crown blocks,wherein
each of the crown blocks is provided with a single crown narrow groove extending from the central circumferential groove to the crown circumferential groove so as to circumferentially subdivide the crown block into two block pieces, the crown axial grooves are each inclined at an angle α of from 10 to 30 degrees with respect to the tire axial direction, the central circumferential groove is a zigzag groove consisting of alternate oblique main parts and inflected parts shorter than the oblique main parts, the oblique main parts are each inclined at an angle β of from 1 to 15 degrees with respect to the tire circumferential direction, the inflected parts are each inclined at an angle larger than the angle β oppositely to the oblique main parts with respect to the tire circumferential direction, the inflected parts are each connected with one of the crown narrow grooves disposed on one side of the central circumferential groove and one of the crown narrow grooves disposed on the other side of the central circumferential groove, the oblique main parts are each connected with one of the crown axial grooves disposed on one side of the central circumferential groove and one of the crown axial grooves disposed on the other side of the central circumferential groove, the central circumferential groove has a depth less than the depths of the crown circumferential grooves, the crown axial grooves are each provided therein with a tie bar rising from the bottom of the crown axial groove so as to connect the circumferentially adjacent two crown blocks to each other, and the crown axial grooves each have an axially inner part which is axially inside the tie bar and has a depth less than the depth of the adjacent crown circumferential groove.