| 摘要 |
PROBLEM TO BE SOLVED: To provide a radial tire, which suppresses the formation of cracks on the bottoms of sub-grooves of shoulder block lines and the heel-and-toe partial wear of the shoulder blocks. SOLUTION: On the tread of the radial tire, at least three main grooves extending in the tire circumference direction are formed, and a plurality of sub-grooves, which extend almost in the tire width direction to connect respective main grooves together and the main grooves to the tread ends, are formed to demarcate more than four of block lines. Raised parts are formed on the bottom of the sub-grooves of the block lines other than the shoulder block lines, respectively, to connect blocks adjacent to each other in the tire circumference direction. Each raised part is formed to have a section of semi-cylindrical shape along the sub-groove, and the maximum height of the raised part is 0.2-0.5 times as large as the maximum depth of the sub-groove. The depth of the sub-grooves of the shoulder block lines is smaller than the maximum depth of the sub-grooves of the block lines other than the shoulder block lines. COPYRIGHT: (C)2004,JPO&NCIPI |
