| 摘要 |
PROBLEM TO BE SOLVED: To suppress the rotation of a bead core, and to improve separation resistance properties of a bead heal.SOLUTION: A pneumatic tire for a heavy load is characterized in that, in a bead core having a polygonal shape, a metal material in a part or the whole region of a tire width inside region in changed to a metal material having a higher elasticity coefficient than steel with a perpendicular line which passes through the center O of the bead core and reaches the bottom of the bead core arranged substantially parallel with bead base face as a reference. When an area of the region in which the metal material is changed is set as A, an area of the region in which the metal material is not changed is set as B, the elasticity coefficient of the metal material not to be changed is set as Ea, and the elasticity coefficient of the region in which the metal material is not changed is set as E, an expression of 1.3≤(A×Ea+B×E)/{(A+B)×E}≤2.0 is satisfied. The metal material is tungsten (W), molybdenum (Mo), or an alloy having a higher elasticity coefficient than steel. |
