Ebe K, Griffin M J
Chemical Products Division, Bridgestone Corporation, Yokohama, Japan.
Ergonomics. 2001 Aug 15;44(10):901-21. doi: 10.1080/00140130110064685.
To improve the understanding of factors affecting automobile seat cushion comfort in static conditions (i.e. without vibration), relationships between the static physical characteristics of a seat cushion and seat comfort have been investigated. The static seat comfort of four automobile cushions, with the same foam hardness but different foam compositions, was investigated using Scheffe's method of paired comparisons. The comfort judgements were correlated with sample stiffness, given by the gradient of a force-deflection curve at 490 N (= 50 kgf). Samples with lower stiffness were judged to be more comfortable than samples with greater stiffness. A similar comfort evaluation was conducted using five rectangular foam samples of the same composition but different foam hardness (and a wider range than in the first experiment). There was no linear relationship between the sample stiffness and seat comfort for these samples. Static seat cushion comfort seemed to be affected by two factors, a 'bottoming feeling' and a 'foam hardness feeling'. The bottoming feeling was reflected in the sample stiffness when loaded to 490 N, while the foam hardness feeling was reflected in foam characteristics at relatively low forces. The pressures underneath the buttocks of subjects were compared with the comfort judgements. The total pressure over a 4 cm x 4 cm area beneath the ischial bones was correlated with static seat comfort, even when the differences among samples were great; samples with less total pressure in this area were judged to be more comfortable than samples with greater total pressure. It is concluded that the pressure beneath the ischial bones may reflect both comfort factors: the bottoming feeling and the foam hardness feeling.
为了增进对静态条件下(即无振动时)影响汽车座垫舒适性因素的理解,已对座垫的静态物理特性与座椅舒适性之间的关系展开研究。采用谢弗成对比较法,对四种泡沫硬度相同但泡沫成分不同的汽车座垫的静态座椅舒适性进行了研究。舒适性判断与样品刚度相关,样品刚度由490牛(=50千克力)时力-挠度曲线的斜率给出。刚度较低的样品被判定比刚度较高的样品更舒适。使用五个成分相同但泡沫硬度不同(且范围比第一个实验更广)的矩形泡沫样品进行了类似的舒适性评估。对于这些样品,样品刚度与座椅舒适性之间不存在线性关系。静态座垫舒适性似乎受两个因素影响,即“触底感”和“泡沫硬度感”。触底感在加载至490牛时的样品刚度中有所体现,而泡沫硬度感在相对较低力时的泡沫特性中有所体现。将受试者臀部下方的压力与舒适性判断进行了比较。坐骨下方4厘米×4厘米区域的总压力与静态座椅舒适性相关,即使样品之间差异很大;该区域总压力较小的样品被判定比总压力较大的样品更舒适。得出的结论是,坐骨下方的压力可能反映了两个舒适性因素:触底感和泡沫硬度感。