Research On The Stamping Forming Of Railway Vehicle Bogie Cover Plate By Numerical Simulation

Railway transportation is the backbone industry in our country. The technology of railway vehicle is the main factor that constraints the development of urban railway transportation. With the rapid development of modern traffic and increasingly drastic market competition, the manufacture of railway vehicle requires much higher about esthetic appearance, comfort and high quality, so the requirement of stamping forming quality and precision of body parts need further improvement. At present, the most effective measure to decrease forming defects is the application of CAE software by numerical simulation of sheet metal before actual production to predict forming defects and shortcomings of mold designing. Then the defects can be controlled by means of optimizing the processing technological parameters and mold parameters. The stamping forming simulation technology of body parts in orbit vehicle is a very helpful technology, because it reduces engineering testing times of new products, thus it shortens the development cycle of the new product and lowers the cost of the new product.This paper takes railway vehicle bogie cover plate as the research object by using ABAQUS software. The lateral bending and springback under bending and drawing forming process by the finite element numerical simulation were analysized, and some control measures to reduce defects and springback during the production of components were provided. This provides a theoretical basis for the actual production.Firstly, the finite element model of bending process was created. The lateral bending and springback situation under bending process by the finite element simulation were analysized.The result shows that the large springback is the main flaw after cover plate bending forming. Additionally, adjusting coefficient of friction, die clearance and other parameters to reduce the springback are not effective. After the forming of parts, there is a certain amount of lateral bending, which is consistent with the lateral bending of the actual production.Secondly, Adding the blank holder on the bogie cover plate in drawing forming processes was proposed. Simulation results show that the drawing forming process can effectively reduce springback and improve the forming precision of thicker sheet. The influence rules of parameters, such as blank holder force, friction coefficient, die clearance and punch radius on the forming formability and springback of the cover plate were analysied.The springback is effectively reduced by increasing the blank holder force. But when the blank holder force increases to a certain extent, the change tendency tends to be stable. The bigger the friction coefficient is, the smaller springback wil be. But much too large friction coefficient will reduce surface quality of the forming parts; With the increasing of die gap, the springback increases. Therefore, it is necessary to choose a smaller and more suitable die clearance to control springback. At last, get the best process plan by orthogonal experiment: the punch die radius is 150 mm, the die clearance is 1.05 t, the friction coefficient is 0.05 and the blank holder force is 2000 KN. In the optimized scheme, the maximum springback is 19.67 mm after drawing forming process, the quality of the cover plate surface is good, and there is no crack or wrinkle defects.In order to further reduce the springback and improve the forming precision, in view of the lateral bending, adding the roof of the back pressure on the die, reverseing bending and amending mould surface were proposed to control the springback. After adding baffles on both sides of the mold, the amount of lateral bending was reduced. The parts are in accordance with the requirements of the forming accuracy.