Pneumatic tire

Abstract

The invention provides a pneumatic tire which can improve the grounding performance of a land line. The tread face of the pneumatic tire is provided with a plurality of main grooves (10) extending ina tire circumferential direction, and a plurality of land lines (20) defined by the plurality of main grooves (10) on the tread face. At least one (22) of the plurality of land lines (20) protrudes outward in a tire diametrical direction from a profile line (PL). A top face (S1) of a central portion of the land line (22) in a width direction is formed in an arc shape protruding outward in the tirediametrical direction in a section along a tire meridian. Top faces (S2, S3) of opposite end portions of the land line (22) in the width direction are formed in arc shapes protruding inward in the tire diametrical direction in the section along the tire meridian.

Description

technical field [0001] The present invention relates to a pneumatic tire in which a land portion row protrudes to a position further outside in a tire radial direction than a contour line. Background technique [0002] Generally, a plurality of land portion rows are provided on the tread surface of a pneumatic tire, and the top surface of each land portion row is aligned with an arc-shaped outline on the tire meridian cross section. On the other hand, as described in Patent Documents 1 and 2, for example, there are known pneumatic tires in which the land portion row protrudes to a position further outside in the tire radial direction than the contour line. The purpose of this tread structure is to improve the ground contact performance of the tread surface, more specifically, to promote the uniformization of the ground contact pressure in the tread surface to improve uneven wear resistance and braking performance. [0003] In addition to improving the grounding performance ...

AI Technical Summary

Problems solved by technology

However, in the tires described in Patent Documents 1 and 2, since the entire top surface of the land portion row is formed in an arc shape convex outward in the tire radial direction, it has been found that there is still room for improvement in the grounding performance of the land portion row. room

This is because: compared with the central part in the width direction that does not face the main groove, the circumferential rigidity is lower at the end of the width direction of the land part row, and the degree of elongation during expansion (Inflet) is relatively large. If the top surface of the row is in the shape of an arc protruding outward in the radial direction of the tire as a whole, the ground contact at the end in the width direction will be excessively strengthened.