BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a pneumatic tire.

Description of the Related Art

A pneumatic tire has a tread, and beads, and has sidewalls arranged between the tread and the beads. There are pneumatic tires in which a rim protector is formed along the entire circumference at a portion of the sidewall that is located toward the exterior in the tire radial direction from the region contacted by the rim flange. It is often the case that the cross-sectional shape of the rim protector is trapezoidal or triangular, being the same every here along the entire circumference of the sidewall.

Japanese Patent Application Publication Kokai No. 2002-59712 discloses that arrangement of a plurality of recesses with spaces therebetween in the tire circumferential direction at a rim protector reduces the thickness of the rim protector and suppresses generation of heat, and that the recesses also cause increase in surface area and improvement in heat dissipation characteristics.

With structures in which there is a rim protector that has recesses which extend continuously in the tire circumferential direction, because thinned regions will be present in continuous fashion in the tire circumferential direction due to the recesses, rigidity will be insufficient and the tire will be susceptible to flexing in the tire radial direction. Structures in which there is a rim protector that has a plurality of recesses which are arranged continuously without gaps therebetween in the tire circumferential direction will likewise have insufficient rigidity.

On the other hand, where a plurality of recesses are arranged with spaces therebetween in the tire circumferential direction as indicated at Patent Reference No. 1, because the spaces between the recesses will constitute projections, it will be possible to suppress decrease in rigidity. However, where a plurality of recesses are arranged with spaces therebetween at a rim protector, it will be the case that the thinned regions and thickened regions from which the recesses are formed will be arranged in alternating fashion along the tire circumferential direction. Strain tends to be concentrated at thinned regions; strain tends not to be concentrated at thickened regions where recesses are not provided. For this reason, regions at which strain tends to be concentrated are therefore arranged with spaces therebetween in the tire circumferential direction.

SUMMARY OF THE INVENTION

It is an object of the present disclosure to provide a pneumatic tire for which decrease in rigidity is suppressed while concentration of strain at recesses of a rim protector is at the same time also suppressed.

According of the present disclosure, there is provided a pneumatic tire having a tread and a bead, a sidewall arranged between the tread and the bead, and a rim protector which is formed at the sidewall and which constitutes an annular protrusion that extends in a tire circumferential direction;

wherein the rim protector has a first protruding edge which extends in the tire circumferential direction and which is toward an exterior in a tire radial direction, a second protruding edge which extends in the tire circumferential direction and which is toward an interior in the tire radial direction, a plurality of recesses arranged in the tire circumferential direction, and a plurality of ridges;

wherein the plurality of ridges respectively connect the first protruding edge and the second protruding edge, and are respectively formed between pairs of the plurality of recesses that are adjacent in the tire circumferential direction;

wherein each of the plurality of ridges comprises a first ridge that extends from the first protruding edge so as to be directed in a first direction in the tire circumferential direction to reach the second protruding edge, and a second ridge that extends from the second protruding edge so as to be directed in the first direction in the tire circumferential direction to reach the first protruding edge; and

wherein the first ridges and the second ridges are arranged in alternating fashion along the tire circumferential direction.

In accordance with this constitution, because not less than two recesses are arranged with spaces therebetween in the tire circumferential direction at rim protector which constitutes an annular protrusion, projections will be formed between pairs of mutually adjacent recesses, and it will be possible to suppress decrease in rigidity more than would be the case with a structure in which pairs of mutually adjacent recesses are arranged without gaps therebetween in the tire circumferential direction. And yet, because mutually adjacent pair(s) of recesses are in positional relationship(s) such that the members of the pair partially overlap as seen when projected onto a virtual plane perpendicular to the tire radial direction, thickened region(s) will be present at said overlapping portion(s), permitting decrease in locations at which only a thinned region is present as viewed in the tire radial direction, and making it possible to decrease locations at which strain is concentrated and to cause strain to be distributed.

