Research On Side Surface Flatness Oversize Of Railway Box Car

This paper describes the research on side surface flatness oversize of railway box car, introduces several dozens years railroad boxcar side surface structure changes in the past several dozens years, various improvement programs to solve surface quality problems of the box car as well. Based on the site examination data, the related test data and the pressing and group welding theory, the cause, the development and the solution have been studied regarding to the problem of side surface oversize of the box car, then the relative work has been carried out adhering to the principle of PDCA. Several typical types of box car have been studied in terms of P64GK box car and P70 box car regarding to side surface flatness quality.Firstly, through the research box car history, the people can understand evolution of the box car side surface structure, as well as various change of side surface flatness following the change of the relative structure and the manufacturing process. The paper also briefly introduces the manufacturing process and surface quality condition for P60, P62, P62N, P64, P64A, P65, P64GK and P70 box car after 70's, describes Russian P63 box car and the box car for Tanzanian Railways manufactured by QRRS. Due to unavailability of conclusive information for previous box cars before 1997, information about the side surface flatness is available for P64GK box car from the year of 2000.Secondly, the paper introduces the main points for selection of the topic. Based on the statistics and analysis, the area for the max. side surface flatness is located, then change trend for the side surface flatness in the process of manufacturing various parts to track down the work sequence mostly affecting the flatness. The theoretical analysis and mechanical engineering is performed in terms of various manufacturing process and deformation of the side surface.The cause and consequences of the flatness and pressing structure of the side sheet is analyzed, the relationship between the side surface flatness and the flatness of various parts as well.The proper welding process and data is finalized on the basis of analysis regarding to the structure, assembly and deformation after welding.Thirdly, according to the above analysis, the proper process is set up to solve the problem of the side surface flatness in terms of structure optimization in design, design and manufacture the pressing tools and fixtures, modification of assembly welding.