truck tire

Abstract

PROBLEM TO BE SOLVED: To suppress stone trapping while minimizing the deterioration of wear life. SOLUTION: A tread part includes a zigzag main groove in which each of groove walls on both sides is extended in a zigzag shape by alternately repeating an external corner-side bent point which is protruded toward the groove width center and an internal corner-side bent point which is recessed toward the groove width center. The zigzag main groove includes an inner zigzag main groove on a tire equatorial surface side. In the groove walls on both sides of the internal zigzag main groove, an external corner-side tapered surface portion is provided at an external corner-side bent portion including the external corner-side bent point by cutting a corner part where the groove wall and the tread surface are crossed by an inclined surface, and an internal corner-side tapered surface portion is provided at an internal corner-side bent portion including the internal corner-side bent point by cutting a corner part where the groove wall and the tread surface are crossed by an inclined surface. The tire circumferential length La of the external corner-side tapered surface portion is different from the tire circumferential length Lb of the internal corner-side tapered surface portion.

Description

technical field [0001] The invention relates to a load-carrying tire, in particular to a load-carrying tire with improved stone trapping resistance. Background technique [0002] In recent years, with the standardization of the road network and the development of high-performance vehicles, many truck tires used for trucks, buses, etc. are used tires that have a plurality of circumferential main grooves extending in the tire circumferential direction on the tread portion. Ribs are used to improve high-speed driving performance, and the above-mentioned circumferential main grooves adopt zigzag grooves to improve traction and braking. [0003] However, when such a truck tire is used to drive on non-paved roads such as gravel roads, stone inclusions are likely to occur in the above-mentioned circumferential main groove, and if the tires are driven with the stone inclusions generated, there is a possibility of damage. The bottom of the ditch will cause tire damage. In particula...

AI Technical Summary

Problems solved by technology

[0005] However, in the case of such two-step tapered grooves, since the rubber volume of the tread portion is reduced by the portion where the tread side wall portion b2 is gently inclined, there is a problem that the wear life of the tire is shortened.

In addition, especially in order to suppress stone inclusion in the curved portion of the zigzag groove, it is necessary to set the angle θ of the tread side wall portion b2 relative to the normal line of the tread tread Ts to be large, for example, 40° or more. In this case, the rubber volume will be further reduced, so the reduction in wear life becomes a bigger problem

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