发动机与整车动力性匹配的研究

Research of Engine and Vehicle Dynamic Performance Matching

通过整车动力性指标及其理论计算公式进行分析,同时对低速加速时间与最大扭矩起始转速的关系进行研究,引入了低速动力因子的概念。通过对样本车辆实际的加速时间进行收集并与其相应的低速动力因子关系进行分析,发0~60 km现低速动力因子与整车低速动力性存在线性的反比关系。低速动力因子越大,说明整车的低速动力性越好。由于实际的整车加速时间除与低速动力因子有关外还与变速器速比、行驶阻力等参数相关,故低速动力因子只能定性评价整车动力性的优劣。尤其在整车预研规划阶段,变速器速比、迎风面积、行驶阻力等基础参数尚未确定时,可通过低速动力因子来评价发动机与整车低速动力性匹配的优劣。通过低速动力因子比较,对整车预研阶段发动机与整车低速动力性匹配具有一定的参考及指导意义。

By analysis of the vehicle dynamic performance index and its calculation formula, this paper studies low-speed acceleration time and the relationship between the rotational speed of maximum torque starting, and introduces the concept of low power factor. By collection of the actual sample vehicle 0 - 60 km to accelerate time and analysis of their corresponding relationship with low power factor, low power factor and the vehicle dynamic performance at low speed is found a linear inverse relation. The greater the low power factor is, the better the vehicle＇s low speed performance is. As a resuh of the actual vehicle acceleration time related to parameters such as transmission ratio, driving resistance, besides to low power factor, the power factor can be evaluated qualitatively the vehicle dynamic performance at low speed. Especially in the vehicle preparatory planning stage, the transmission speed ratio, windward area, driving resistance, has not yet been determined, the merits of the matching of engine and vehicle dynamic performance at low speed can be evaluated through the low power factor. By comparing with low power factor, matching of engine and vehicle dynamic performance at low speed has certain reference and guidance significance for vehicle in preparatory phase.