固定辙叉查照间隔及心轨加宽研究

Study on Guard Check Gauge of Fixed Frog and Design on Widening Nose Rail

针对我国铁路固定辙叉轮载过渡区域翼轨和心轨因总承载面积小而导致使用寿命短、更换极为频繁的问题,进行固定辙叉查照间隔合理取值及心轨加宽设计研究.根据现有的车辆轮对尺寸和容差,推导出现有行车条件下固定辙叉查照间隔应大于等于1388 mm,护背距离应小于等于1348 mm.经大秦线和朔黄线现场测试,验证了该修订后的查照间隔取值是正确的,并具有一定的安全余量.根据修订后的查照间隔值,心轨每侧可加厚4mm,心轨实际尖端至50 mm断面可加厚8mm,使心轨承压面积增加30％,从而提高了心轨薄弱断面的粗壮度,可防止心轨轨头宽20～40mm断面区段的压塌,降低磨耗,大大延长辙叉的使用寿命.在朔黄铁路西柏坡站铺设据此设计和试制的新型合金钢组合辙叉,进行现场试验,结果表明：该辙叉经逆向通过约20万个轮对后状态依然良好,辙叉区动态轮轨游间为2～3 mm,可保证行车安全.

The service life of fix frog is short and thus must be frequently replaced due to the small total load area of nose and wing rails near its wheel load transition region,so it is necessary to study the reasonable value for the guard check gauge of fixed frog and design on widening nose rail.According to the current wheelset size and tolerance,the guard check gauge of fixed frog is deduced,which should be greater than or equal to 1388 mm,and the guard rail face gage should be less than or equal to 1348 mm under current train operation conditions.The field tests of Datong-Qinhuangdao Line and Shuozhou-Huanghuagang Line have validated that the revised value for guard check gauge is correct and has some safety margins.Based on the revised value for guard check gauge,each side of nose rail can be widened about 4 mm.The nose rail can be thickened about 8 mm from its practical tip to 50 mm section,which can increase the bearing area of nose rail by 30％ and accordingly strengthen the weak section of nose rail.The collapse of 20～40 mm wide section zone of nose rail head can be prevented,the wear can be reduced and the service life of frog can be greatly extended.The new designed and trial-manufactured alloy steel frogs were laid on the Xibaipo Station of Shuozhou-Huanghuagang Railway and field tests were conducted.Results show that the frogs are still in good conditions after approximately 200 000 wheelsets passing through conversely.The dynamic clearance between wheel flange and gage line of the frog is 2～3 mm which is able to ensure train operation safety.