固定辙叉心轨轨顶降低值优化

为合理选取固定辙叉心轨轨顶降低值,基于车轮踏面在翼轨和心轨间过渡时的轮轨接触几何关系和动力相互作用,提出了心轨关键断面降低值的选取及评价方法.以LMA型车轮踏面列车直逆向通过60 kg/m钢轨12号固定辙叉式道岔为例,用该方法对心轨轨顶降低值进行了优化.结果表明:心轨关键断面降低值的确定,在满足固定辙叉区轮载过渡的安全性和心轨承载断面强度要求的同时,应提高列车运行的稳定性;断面降低值越小,产生的轮轨相互作用越小,有利于提高行车性能,但需考虑此时轮轨作用位置是否超出心轨结构承载能力范围;60 kg/m钢轨12号固定辙叉心轨顶宽20和50 mm断面处,可分别取3和0 mm降低值作为优选方案. 

Optimization of Nose Depth for Rigid Frog

Based on wheel-rail contact relationship and dynamic interaction when wheel treads pass from wing rail to nose rail, a design and evaluation method for nose depth selection of key cross-sections was proposed to select reasonable nose depths for rigid frog. A train with LMA wheel treads passing over No.12 turnout of rigid frog in the facing move of the straight direction was taken as an example, and the optimization of nose depths was carried out by this method. The research results show that the nose depths of key cross-sections should not only satisfy the safety of wheel-load transition and the strength of nose rail, but also improve the train running stability. The smaller the nose depth, the smaller the wheel-rail interaction, which is helpful to improve the running performance, but whether the wheel-rail interaction location exceeds the scope of nose bearing capability should be taken into account. To a No.12 turnout of rigid frog, the optimal nose depths of the cross-sections with railhead widths of 20 and 50 mm should be 3 and 0 mm respectively.