Simulation Analysis Of No.18 High-speed Turnout Conversion With Considering The Influence Of External Locking Device

With the development of high-speed rail technology,the running speed of railway trains has been continuously improved,and the insufficient displacement caused by the conversion of turnouts has become one of the main factors restricting the speed increase of high-speed trains.The insufficient displacement will directly affect the safety and stability of driving.In order to control the insufficient displacement within the limit range,it is necessary to ensure that the conversion force does not exceed the rated power of the switch,and the total power of the switch needs to have a certain margin,so that calculation of the conversion force can be controlled.In this paper,the No.18 high-speed turnout is taken as the research object.According to the structure of the turnout and the actual conversion action,the process of the conversion and the movement of the external locking device are combined to propose a more accurate method for solving the switch conversion force.The conversion calculation model is used to study the variation law of turnout conversion force with time,and the influencing factors of turnout conversion force are explored and analyzed.In this paper,based on the finite element theory,the turnout pulling model and the external locking device motion and force analysis model are established respectively.The turnout pulling model is simulated by the elastic two-dimensional cantilever beam according to the turnout structure,and the equilibrium equation is using variational principle of minimum potential form to establish.The model,in addition to the rebound force,the adhesion force,the top iron reaction force,the sliding plate friction and other factors generated during the turnout conversion process,also considers the conversion speed,the peak start time of each traction point,and the unlocking time of the external lock.The curve of the turntable dynamics with respect to time is obtained after the solution;the motion and force model of the external locking device considers the motion of each key component according to the force transfer process between the tip rail or the core rail and the locking rod.With the state of force,the corresponding finite element two-dimensional model is established,and the function of the force at the waist of the turnout is determined has a function with the force at the locking bar.Through the model,the paper analyzes the influence of the difference of the action time,and the existence of foreign objects between the tip and the rail on the switching force of the turnout.Computational analysis shows that the starting time difference of the traction point has a significant influence on the switching force.The conversion force required to complete the locking when the traction points are synchronized is the smallest,and the larger the movement time difference,the conversion force also increases.The foreign matter is attracted to the traction point in the vicinity of the traction point and the conversion force is significantly increased,and is proportional to the size of the foreign object.To ensure the turnout can be converted and locked in place,the foreign object cannot be too close to the traction point.And the size needs to be controlled within a certain range.