| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently even the grounding pressure of a surface of a tire over the whole of the tire by forming a surface of a block with a curvature radius smaller than the curvature radius of an outline of a tread surface in at least one of the circumferential direction and the axial direction of the tread. SOLUTION: In block lines 1, 2 arranged most close to the pattern center PC, surfaces 3a, 4a of each block 3, 4 are formed with a curvature radius r, r smaller than the curvature radius R of an outline 5 of the tread surface in the only cross direction B of the tread, and each block 3, 4 is formed into a semi-cylindrical shape having a vertex part extended in the circumferential direction A of the tread. At this stage, surfaces 3a, 4a of the blocks 3, 4 respectively have the same curvature radius with the curvature radius of the outline 8 of the tread surface, and the curvature radius R of the outline 8 passes a ridge of the vertex part positioned at a central part in the cross direction of the blocks 3, 4 of each block line 1, 2. |
