| 摘要 |
PURPOSE:To improve mud removing and grip properties by widening a rise section of each knob on the bottom, making the cross section of tread section flat in such a way that the height of knob is large on the tire side, and providing a recessed section which has the bottom in a knob head section. CONSTITUTION:A knob 5 is provided with recessed sections 9L, 9R in a head section, and the section of a line 12 where a tilted flat section 10 and a curve section 11 which becomes deep sequentially cross is used as the bottom. A rise section of the knob 5 is wide on the bottom, and the angle alpha which is formed by a side wall section and the tangent line of tire carcass in the lower section is 40 to 75 degrees. Further, knobs 6L and 6R form a recessed section 13 in its head section by tilted faces 14 and 15, and the section of a line 16 where these faces cross is used as the bottom. The angle beta which is formed by faces 14 and 15 is 145 to 170 degrees. The height of knob becomes large on both sides in such a way that the cross section of tread section becomes flat. On the other hand, knobs 7L and 7R and 8L and 8R are formed in the same way as the above. |
