高速道岔转辙器结构及牵引动程优化研究

Study on Optimization of Structure and Traction Range of High-speed Railway Turnout Switches

搭建18号高速道岔尖轨转换原型试验平台,并分析可动段长度、尖轨预弯、固定端扣件支距以及滑床板摩擦系数等因素对尖轨不足位移的特征及其影响机制。建议采用减小尖轨可动段长度的方法来控制不足位移,将尖轨固定端前移600 mm,不足位移可减小8.6%。对转辙器结构进行优化设计,将直、曲尖轨最后一块滑床板修改为固定垫板。底板尺寸保持不变,滑床台上方增设2个铁座扣压尖轨,铁座非工作边竖立面设计为斜面,减小底部宽度以适应滑床台上的有限空间;仍采用同规格弹性夹扣压基本轨,取消滑床台压舌缺口。针对优化结构对转辙器牵引动程进行匹配优化,基于有限元理论,充分考虑尖轨实际受力特征及空间变截面特性,建立转辙器区尖轨斥离状态弹性变形线形的精细化计算模型。基于数值试验结果,建议新型高速道岔转辙器区第1牵引点动程保持不变,第2牵引点动程由原来的118 mm增加至124 mm,第3牵引点动程由原来的71 mm增加至75 mm,可确保最小轮缘槽留有与既有高速道岔相同的安全裕量,同时可改善尖轨的变形协调性,有利于提升其长期服役状态及寿命,第3牵引点扳动力比既有高速道岔略有增加,但仍远小于限值要求。本文研究可为速度为400 km/h高速道岔研发提供理论依据和参考。

A prototype test platform for the switching of No.18 high-speed turnout switch rail was established to study the influence mechanism and characteristics of movable section length,switch rail pre-bending,fixed end fastener support offset,and slide baseplate friction coefficient on scant displacement.It is recommended to reduce the length of the movable section of the switch rail to control the scant displacement.Moving the fixed end of the switch rail forward by 600 mm can reduce the scant displacement by 8.6%.The structure of the switch was optimized by modifying the last slide baseplate plate of the straight and curved switch rail to a fixed baseplate.The size of the bottom plate remained unchanged,with two iron seat fastening switch rails added above the slide chair,and with the vertical elevation of nonworking side of the iron seat designed as a bevel,to reduce the bottom width to adapt to the limited space on the slide chair.The elastic clip of the same specification was still used to press the stock rail,with the tongue depressor notch of the slide chair eliminated.The traction displacement of the switch was matched and optimized for the optimized structure.Based on the finite element theory and full consideration of the actual force characteristics of the switch rail and the characteristics of the spatial variable section,a refined calculation model was established for the elastic deformation linear shape of the switch rail in non-working state in the switch rail repulsion state.Based on the numerical test results,it is suggested that the first traction point displacement of the new high-speed turnout switch area remain unchanged,with the second traction point displacement increasing from the original 118 mm to 124 mm,and the third traction point displacement increasing from the original 71 mm to 75 mm,which can ensure the same safety margin of the minimum flangeway as the existing high-speed turnout,as well as the improvement of the deformation coordination of the switch rail,which is conducive to improving its long-term service status and lifespan.Despite the slight increase of the trigger force of the third traction point compared to that of the existing high-speed turnout,it is still far less than the limit value requirement.This study can provide theoretical basis and reference for the development of the turnouts of high speed railways with a speed of 400 km/h.