道岔区轮轨间隙动态变化特性研究

轮轨间隙对车辆顺利通过道岔具有十分重要的作用．在车辆-道岔系统动力学模型基础上，利用道岔区钢轨空间布置和轮轨接触几何关系，分析了护轨对轮轨间隙的限制作用和对轮对冲击心轨的防护机理，研究了道岔区轮轨间隙动态变化特性，轮轨间隙与轮对横移量、轮轨横向冲击力、轮轨接触角之间的关系，以及轮轨间隙变化对车辆过岔运行安全性和道岔系统稳定性的影响特性．结果表明，轮轨间隙不仅与轨距和钢轨动态横移量有关，而且与轮对横移量密切相关，且当间隙过小时轮轨间将发生横向冲击振动；设置护轨有利于防止轮对冲击心轨，并使得轮对能够顺利通过岔心；另外，为使车辆能够顺利通过道岔，在允许的情况下可以适当增大转辙区轨距，但心轨区轨距最好保持标准值．

Dynamic Characteristics of Wheel/Rail Clearance in Turnout Zone

The wheel/rail clearance plays an important role in promoting railway vehicle to successfully pass through the turnout zone.Based on a vehicle-turnout spatial couple model and the wheel/rail geometrical contact theories,the dynamic characteristics of the wheel/rail clearance and the relationship between the clearance and the lateral displacements of the wheelset and rails,wheel/rail lateral impacting forces and the wheel/rail contact angle are presented in this paper.Moreover,the safeguard mechanism of the guard rail to the nose rail and the effects of the wheel/rail clearance to the system stability and operating safety are analyzed.It is shown that the wheel/rail clearance is tightly correspondent with the lateral displacement of the wheelset,and the intense lateral impacts between the wheels and rails would take place if the clearance is in much shortage.In order to promote the vehicle successfully pass through the turnout zone,the clearance in the switch area should be reasonably boarded if it is possible,and the clearance in the frog area should be retained standard figure.Additionally,it is very helpful of guard rail setting to protect the nose rails.