列车空气制动均衡速度的局部稳定性

Local Stability of Balancing Speed of Train under Condition of Air Brake

为了研究空气制动工况下列车均衡速度的稳定性，分析了列车均衡速度与单位合力函数单调性的关系．当单位合力函数单调递减时，列车均衡速度稳定，否则，其均衡速度不稳定．因此，在空气制动工况下，单位合力函数在部分速度区间单调递减，均衡速度存在局部稳定性，并采用二分法计算了均衡速度稳定的速度区间．以SS4型机车牵引中磷闸瓦空货车为例，列车运行限速和制动初速度为100km／h，其临界速度为53．5km／h，当列车速度为53．5-100km／h时，空气制动下均衡速度是稳定的．

In order to probe into the stability of train＇s balancing speed under the condition of air brake, the relationship between its balancing speed and the monotonicity of the function of train unit resultant force was investigated. When the function of train unit resultant force is monotonously decreasing, the balancing speed is stable, otherwise it is instable. Therefore, under the condition of air brake the function of train unit resultant force is monotonously decreasing in some speed range, and the balancing speed is stable locally. The speed range in which the balancing speed is stable was calculated by using the dichotomy. To an empty freight train with an initial brake speed of 100 km/h equal to its limit running speed, drawn by an SS4 locomotive with medium phosphor cast iron brake shoes, its critical speed is 53.5 km/h. So when its running speed is between 53.5 and 100 km/h, the balancing speed is stable under the condition of air brake.