| 摘要 |
PROBLEM TO BE SOLVED: To design a mold which satisfies conditions of the life prediction of members such as sipes and bones and of their desired lives by using specified formulas. SOLUTION: Formulas I and formula II are used, whereinΔεt : the total strain width received by a member by a repeated load,σB: strength at break (kgf/mm<2> ), E: a Young' modules (kgf/mm<2> ),εf : a true strain width at break, Nf: a repeated fatigue life (cycle), Z: a cross-sectional coefficient (mm<3> ), h: a height (mm),θ: a mold release angle (deg.), e: the Young' modules of a rubber material for tires (kgf/mm<2> ), an attached letter A: a standard member, an attached letter B: represents a member to be predicted. In the formula I, the total strain widthΔε1 A is obtained by substituting the repeated fatigue life NfA obtained from the measured value of a used material A and each value of physical properties. Next, in the formula II, the total strain widthΔε1 B is obtained by substituting this value and each value of physical properties of the used material A and a new material B. Finally, using this value, again, a repeated fatigue life NfB in which the new material B is used from the formula I. |
