高速铁路道岔尖轨不足位移控制方法

为模拟运营条件下高速铁路道岔转辙器的转换过程，根据高速铁路道岔转辙器的转换特点，在道岔生产车间内建立了客专线18号道岔转辙器转换原型试验平台，采用轴销式称重传感器测量转辙器扳动力，以直、曲尖轨支距实际值与理论值之差为尖轨不足位移；通过转辙器转换试验探索了尖轨预弯、尖轨可动段长度、尖轨固定端扣件支距、滑床板摩擦因数、辊轮高度等因素对尖轨不足位移的影响机制和特征。试验结果表明:现有设计尖轨预弯可使尖轨不足位移下降30%以上；缩短尖轨可动段长度可减小尖轨不足位移，但同时会减小转辙器最小轮缘槽宽，并增大第3牵引点扳动力，尖轨最小轮缘槽宽和最后一个牵引点扳动力是缩短尖轨可动段长度的控制因素；小范围调整固定端所有扣件支距后，尖轨不足位移变化较小，仅减小固定端第1组扣件支距时，尖轨靠近固定端1.2 m范围内不足位移略有降低，其余部分不足位移变化较小；在滑床板上安装辊轮或涂覆润滑剂等减小尖轨与滑床板摩擦因数的措施可有效降低尖轨扳动力和不足位移，实施减摩措施后，扳动力减幅约为30%，不足位移减幅超过20%；改变辊轮高度对尖轨不足位移的影响并不明显，但辊轮高度不宜过低，以防转换过程中辊轮失效导致扳动力和不足位移激增。研究结果可为高速铁路道岔转辙器结构优化和新一代400 km·h-1高速铁路道岔的研发提供参考。 

Control method for insufficient displacement of switch rail in high-speed railway turnout

To simulate the switching process of high-speed railway turnout switch under operating conditions, according to the switching characteristics of high-speed railway turnout switch, an experimental platform of the switching prototype of passenger dedicated railway No.18 turnout switch was established in a production workshop of turnout. The shaft pin type load cell was used to measure the switching force of the switch, and the difference between the actual and theoretical offset distances of straight and curved switch rails was taken as the insufficient displacement of switch rails. Switching experiments were carried out to explore the influence mechanism and characteristics of switch rail pre-bending, movable section length of switch rail, offset distance of fasteners at the fixed end of switch rail, friction coefficient of slide plate, and height of roller on the insufficient displacement of switch rail. Experimental results show that the designed switch rail pre-bending can reduce the insufficient displacement of switch rail by more than 30%, and the shortening of the movable section length of switch rail can reduce the insufficient displacement of switch rail, but decrease the minimum wheel flangeway width of the switch and increase the switching force at the third traction point. The minimum wheel flangeway width of swith rail and the switching force at the last traction point are the control factors for shortening the movable section length of switch rail. After the adjustment of the offset distances of all fasteners at the fixed end in a small range, the change of insufficient displacement of switch rail is small. When only reducing the offset distance of the first group of fasteners at the fixed end, the insufficient displacement of switch rail decreases slightly within the range of 1.2 m close to the fixed end, and the insufficient displacements at other sections change slightly. The measures of reducing the friction coefficient between the switch rail and the slide plate, such as the roller installation and lubricant coating on the slide plate, can effectively reduce the switching force and insufficient displacement of switch rail. After the implementation of these antifriction measures, the switching force decreases by about 30%, and the insufficient displacement decreases by more than 20%. The influence of changing the height of roller on the insufficient displacement of switch rail is not obvious, but the height of roller should not be too low, in order to avoid a surge in the switching force and insufficient displacement caused by the failure of roller in the switching process. The research results can provide important references for the structure optimization of high-speed railway turnout switch and the development of a new generation of 400 km·h-1 high-speed railway turnout. 7 tabs, 20 figs, 31 refs.