机械

为分析不同制动操作对现有2万吨重载列车纵向冲动的影响，基于重载列车纵向动力学理论和车辆动力学理论，考虑了2万吨重载列车的牵引与动力制动特性、空气制动系统以及钩缓装置等多方面因素，建立了一个适用于2万吨重载组合列车的纵向动力学计算模型，并通过现场测试数据对其进行了有效验证。该模型被进一步用于对比分析运行线路条件、空气制动压力、同步控制延时以及机车电制动力等多个参数对列车纵向冲动的影响程度。研究发现，当列车从陡坡过渡到缓坡的线路条件下制动时，纵向冲动的影响最为显著。此外，坡度差越大，产生的纵向压钩力也越大。同步控制延时的长度以及机车电制动力的大小也对列车的纵向冲动有显著影响：延时越短，电制动力越小，纵向冲动越小。在列车通过曲线轨道时，若将纵向冲动力控制在安全范围内，能有效提升重载列车的行车安全性。这一研究成果为重载列车制动策略的优化提供了重要的理论依据和实践指导。

To analyze the impact of different braking controls on the longitudinal impulse of the existing 20000-ton heavy-haul train, a longitudinal dynamic model of a 20000-ton heavy-haul train is established in MATLAB based on the theories of longitudinal dynamics and vehicle dynamics. In this model, the relevant factors of train longitudinal motion, including the traction and dynamic braking characteristics of the locomotive,the air braking system of the train and the characteristics of the coupler-buffer device are taken into account. The effects of line conditions, air braking pressure, synchronous control delay, the electric braking force of the locomotive and other parameters on the longitudinal impulse of the 20000-ton heavy-haul train are analyzed.The analysis results indicate that the line conditions of steep to gentle slopes have the most significant impact on the longitudinal impulse when the 20000-ton heavy-haul train employs braking. And the coupler compressive forces would increase with the increase of the slope difference. The synchronous control delay and the electric braking force of the locomotive have a significant impact on the longitudinal impulse of the 20000-ton heavy-haul train during braking. The longitudinal impulse would reduce with the decrease of the synchronous control delay and the electric braking force. And controlling the longitudinal coupler force within a safe range can enhance the safety of the vehicle operation. The result provides significant theoretical support and practical guidance for optimizing the braking strategies of heavy-haul trains.