Patent ID: 8261793
Filing Date: 2012-09-11
Classification: B60C,Y10T

Abstract:
1. A pneumatic tire comprising: a pair of bead portions in which a bead filler is arranged; side wall portions extending to an outer side in a tire diametrical direction from the bead portions; a tread portion connected to an outer side end in the tire diametrical direction of each of the side wall portions; and a carcass ply rolled up in its end portion in such a manner as to pinch the bead filler, wherein an outer surface of the side wall portion is provided with a concavo-convex region formed by arranging a lot of projecting lines extending in a tire circumferential direction in parallel in the tire diametrical direction, a pitch of the projecting lines is between 0.4 and 3.0 mm, and the height of the projecting lines is the distance from a reference profile line of the side wall portion to a vertex of the projecting lines and is between 0.2 and 2.0 mm, and an arranged density of the projecting lines becomes larger toward the outer side in the tire diametrical direction, and wherein an outer peripheral end of the concavo-convex region is positioned in the outer side in the tire diametrical direction than a position where an interface between a tread rubber arranged in the tread portion and a side rubber arranged in the side wall portion is exposed, and an inner peripheral end of the concavo-convex region is positioned in an inner side in the tire diametrical direction than a leading end of the bead filler, and further comprising a first region at a first position where the interface formed by the tread rubber and the side rubber are exposed, a second region at a second position where the rolled up end portion of the carcass ply pinches the bead filler, the second position being at an inner side in the tire diametrical direction from the first position, and a third region at a third position where the leading end of the bead filler terminates, the third position being at an inner side in the tire diametrical direction from the second position each of the first second and third regions having cross sectional heights of 10 mm around their respective first, second and third positions, wherein the pitch of the projecting lines in the first region is between 0.4 and 1.0 mm, the pitch of the projecting lines in the second region is between 1.0 and 2.0 mm and the pitch of the projecting lines in the third region is between 2.0 and 3.0 mm.