Pneumatic tire

摘要

A pneumatic tire is provided in the outer surface of each sidewall portion with a serrated zone formed by a number of serration grooves extending at an angle of at most 45 degrees with respect to the tire radial direction. Each of the serration grooves has a variable depth such that the deepest point lies between the radially outermost end and innermost end of the serration groove. The deepest point is positioned in a range between 0.2 time and 0.4 times a radial distance Ha from the maximum carcass section width position to the radially outermost end of the tire. As a result, the rolling resistance of the tire can be reduced.

主权项

1. A pneumatic tire comprising
a tread portion, a pair of sidewall portions, a pair of bead portions, and a carcass which extends between the bead portions through the tread portion and the sidewall portions, defining a maximum carcass section width position at which the maximum section width of the carcass occurs, wherein the sidewall portions are each provided in the outer surface thereof with a serrated zone formed by a plurality of serration grooves all of which extend at an angle of not more than 45 degrees with respect to the tire radial direction, the serration grooves each have a variable depth so that its deepest point occurs between the radially outermost end and radially innermost end of the serration groove, the variable depth increasing gradually from the radially outermost end to said deepest point and increasing gradually from the radially innermost end to said deepest point, the deepest point is positioned in a range between 0.2 times and 0.4 times a radial distance Ha from the maximum carcass section width position to the radially outermost end of the tire, and in each sidewall portion, a thickness between the bottom of each serration groove and a main portion of the carcass becomes minimum at a radial position within a range between 5 mm radially outward and 5 mm radially inward of the deepest point.