| 摘要 |
PURPOSE: A measuring method of friction coefficient is provided to presume a frequency N of the vibration generated by contacting between a rubber block and a surface and to preciously measure a friction coefficient of a tire because a driving condition such as a condition of a surface and a driving speed are quantitatively organized. CONSTITUTION: A measuring method of friction coefficient comprises the next step. A sliding speed VS of a driving rubber block is measured. A height Z at a point X of the surface is measured through projecting lights by a surface roughness gauge so that a condition of the surface is digitized. A altitude difference correlation function Cz (λ) indicated by a formula(3) is calculated so that a longest horizontal correlation length ξ h is obtained. A dissipative function σ(x) indicated by a formula(1) and gamma function Γ z (λ) indicated by a formula(2), data including a location X and a height z(x) are used when longest horizontal correlation length ξ h is obtained. A frequency N of the vibration generated by contacting between a rubber block and a surface is presumed through dividing the sliding speed VS by the longest horizontal correlation length ξ h. A reference sample containing a rubber composition same with the contacted area with a surface of the rubber block is prepared. A master curve of a loss tangent is manufactured by measuring the loss tangent of a sample. The loss tangent corresponding to the frequency N of the vibration is presume. Formula(1) : σ(x)=[{z(x)-(z)}] Formula(2) : Γ=[{z(x+λ)z(x)}]-[z(x)] Formula(3) : C(λ)=2(σ-Γ(λ)) |
