| 摘要 |
PROBLEM TO BE SOLVED: To enhance a pneumatic tire in its operational stability on both dry and wet road surfaces by arranging longitudinal grooves at slant angles within a range of specific angles in relation to a tread surface circle and providing rising parts on the groove bottoms of both grooves as well as arranging lateral grooves formed on the tread surface of a tread part at slant angles within a range of a specific angle in relation to the tread surface width direction. SOLUTION: In the central range of both sides for pinching the equatorial surface E of the tread surface 2 of a tread part 1 in a pneumatic tire, many lines of lateral groove 3 for crossing this tread surface 2 from one side end edge S to the other side end edge S and many lines of longitudinal grooves 4 which cross those lateral grooves 3 and mutually connect and extend are formed. In this case, lateral grooves 3 are arranged at 10 to 50 deg. slant angle in relation to the lateral direction of the tread surface 2 and the longitudinal grooves 4 are arranged at 0 to 40 deg. slant angle in relation to the circle of the tread surface 2. Meanwhile, grooves 3, 4 mutually cross and communicate with each other at positions 5 and rising parts 6 are provided on the groove bottoms of grooves 3, 4 that include these positions 5 and extend from the positions 5 in four directions. By means of these rising parts 6, any damaging force caused by biting foreign matters is relaxed owing to an increase in the thickness of rubber. |
