表面塗装が本革ステアリングホイールの「握り心地」評価に及ぼす影響

摘要

We investigated how the surface coating of leathers influenced 'touch feeling' and 'grip comfort' of leather steering wheels. Four leather sheets coated by different urethane coating materials and four steering wheels covered by these leathers were used as samples. Both 'touch feeling' of the leather sheets and 'grip comfort' of the steering wheels were evaluated by the paired comparison method. Then each mean preference score of 'touch feeling' and 'grip comfort' was examined by the principal component analysis. From the result, it was found that 'moisture' and 'smoothness' were identified as principal factors of 'touch feeling' and 'grip comfort'. And the physical properties (i.e. compression, friction, surface roughness, and q-max) of the leather sheets were measured. The relationship between the subjective evaluation (i.e. 'touch feeling' and 'grip comfort') and these measured physical properties were investigated. From the result, it was found that 'moisture' was correlated significantly with 'MIU/MMD' (MIU: mean coefficient of friction, MMD: mean deviation of MIU) and 'dry' was correlated significantly with 'Ra' (arithmetic mean deviation of the roughness profile). The measuring method of the physical properties was viable approach for the quantitative evaluation of 'grip comfort'.%自動車に求められる性能には,安全性や環境負荷の低減,走行性能などが挙げられるが,新たな付加価値として車内の居住空間の快適性が求められている.特に,ドライバーが運転中に保持するドライビングポジションはフットペダル,シート，ステアリングホイールによって決定される.その中で,ドライバーが運転中に常時手で触れて意図する方向へ自動車を走行させるマンーマシンインタフェースとして重要な役割を担うのはステアリングホイール（以下S／W と呼ぶ）である.