Patent ID: 8646498
Filing Date: 2014-02-11
Classification: B60C

Abstract:
1. A pneumatic tire having a tread pattern in a tread section, wherein in each of two regions disposed on opposite sides of a tire centerline in the tread section, the tread pattern includes: two circumferential main grooves that are provided side-by-side along a tire widthwise direction of the tire and configured to extend along a tire circumferential direction of the tire in a zigzag shape such that they are slanted at a slant angle with respect to the tire circumferential direction and exhibit a position variation in a widthwise direction of the tire; a plurality of first lug grooves that are arranged along the tire circumferential direction and configured to extend from an inner circumferential main groove, which is the circumferential main groove of the two circumferential main grooves that is located closer to the tire centerline, and each of the first lug grooves being slanted with respect to the tire circumferential direction, with an angle at an intermediate portion of each of the first lug grooves being larger than another angle at a portion of each of the first lug grooves other than the intermediate portion, and reaching a pattern end of the tread pattern; and a plurality of second lug grooves that are arranged along the tire circumferential direction, and configured to extend toward the pattern end from an outer circumferential main groove, which is the circumferential main groove of the two circumferential main grooves that is located more toward an outside of the pneumatic tire in a tire widthwise direction, and at least one of the second lug grooves is arranged between two of the first lug grooves that are adjacent to each other along the tire circumferential direction; a side wall of the inner circumferential main groove that is located closer to the tire centerline including a groove-wall-angle varying wall surface configured such that a groove wall angle with respect to a tire radial direction increases in the tire circumferential direction; an outside land section that is demarcated by the inner circumferential groove, the outer circumferential groove, and two of the first lug grooves arranged adjacent to each other in the tire circumferential direction being positioned facing opposite a portion of the groove-wall-angle varying wall surface with the inner circumferential groove disposed in-between, the outside land section including a notched lug groove that extends in the tire widthwise direction from either the inner circumferential main groove or the outer circumferential main groove and closes in a region within the outside land section; a groove depth of the notched lug groove is shallower than a groove depth of the first lug grooves where they pass by adjacently to the outside land section and shallower than a groove depth of the second lug grooves where they extend from the outer circumferential main groove; a groove width of the first lug grooves is 1.2 to 2.5 times larger than a groove width of the second lug grooves; and a groove depth of the second lug grooves at positions where the second lug grooves extend from the outer circumferential main groove is shallower than a groove depth of the first lug grooves at positions where the first lug grooves intersect the outer circumferential main groove.