Research on Technique for Correction of Running Resistance with Focus on Tire Temperature and Tire Thermal Balance Model

摘要

At present, measurements of running resistance are conducted outdoors as a matter of course. Because of this, the ambient temperature at the time of the measurements has a considerable impact on the measurement data. The research discussed in this paper focused on the temperature characteristic of the tires and developed a new correction technique using a special rolling test apparatus. Specifically, using a tire rolling test apparatus that made it possible to vary the ambient temperature, measurements were conducted while varying the levels of factors other than temperature that affect rolling resistance (load, inflation pressure, and speed). Next, a regression analysis was applied to the data for each factor, and coefficients for a relational expression were derived, making it possible to derive a quadratic equation for the tire rolling resistance correction formula. It was verified that the application of the new correction formula reduced variation in running resistance from 2.7% (in the case of regulation correction) to 1.0%. In addition, in order to offer a simpler method of realizing the same correction, a technique for correction using a conventional tire rolling test apparatus and based on the material characteristics of the tire tread rubber was also developed. It was verified that this method allowed the same degree of correction. Giving consideration to the application of the method to future tire modeling, the development of heat generation and dissipation models for tire rolling tests was also examined. The addition of terms for the temperature characteristic of the tread rubber and heat generation and dissipation between the tire and the drum reduced error between measured and predicted values to ±0.6%.