Urban Rail Vehicle Body Weighing Load System Research

With the acceleration of urbanization, the urban mass transit is developing rapidly, which demands metro vehicle’s promotion in terms of manufacture and running quality. The distribution of vehicle wheel (axle) load is of great importance to the improvement of vehicle running quality. The load test and spring adjustment system for metro car body is a necessary technological device for the level test which is an important method to balance the wheel (axle) load within the standard range.Based on the analysis of the level test process, actual requirements in the development of the load test and spring adjustment system for metro car body have been studied. According to the system function and the relevant technical specifications, the overall components are defined with their interrelations; The lifting units which are the main executive mechanism for measure-control system have been designed and analyzed. Some key parts are analyzed by finite element method (FEM), and the results show that the lifting units is designed wiht good stiffness and strength; On the research of the classical contact analysis and FEM contact analysis, contact calculations are carried out on the components of lifting units. By analyzing the cumulation and amplification of the deformation by mechanical structure, an empirical formula for the vertical displacement of the bearing surface is established; The results of the static load test show that the structure of lifting units meets the requirements. The vertical displacement of the ram is obtained during the test, and the maximum error between the measurement and finite element analysis is 3.35%, which prove the usability of the empirical formula; On the basis of studying the measurement and calculation of static loads on car body in DIN 25045, an algorithm for the load test and spring adjustment is proposed, via using the algorithm, the adjustment to the tension free position will be carried out by moving the lifting points of the car body until the force difference is less then the standard.The system has been put into use after installation and commissioning, it stands for the highest levels on automation, intelligence and reliability in the similar productions which are large-scale special devices in the manufacture of metro car body.