Study On The Micro-deformation Of The Split Axle Box Bearing Hole

The axle box is installed on both ends of the railway vehicle axle,and connects the wheel set and bogie frame.It is one of the key components to ensure the comfort and safety of the railway train.An enterprise adopted the structure of the split axle box.However,the dimension of the axle box bearing hole was unstable and the bearing hole was deformed after processing,resulting in increased manufacturing costs and longer production cycle.Therefore,it is necessary to find out the reasons for the instability of bearing hole,and put forward measures to improve the qualification rate of the axle box.Firstly,the precision boring experiment of the split axle box bearing hole was carried out with different machining parameters.We measured the cutting force,and cutting temperature during processing,and used the three-coordinate measuring instrument to measure the size of the bearing hole after different aging time.we carried out the cutting simulation by using ABAQUS,and analyzed the influence of different cutting parameters and different tool parameters on cutting force and cutting temperature.Secondly,We used the X-ray diffraction method to test the residual stress of bearing hole of both after cutting and without cutting.We concluded that the residual stress is the main reason for the deformation of the bearing hole of the axle box after cutting.We used ABAQUS simulation to analyze the influence of different cutting parameters and different tool parameters on the residual stress of axle box.Moreover,we analyzed the method of reducing and eliminating the residual stress of the bearing hole so as to reduce the micro-deformation.Thirdly,We built a model for the split axle box by using UG,and imported the model to ANSYS to simulate the influence of sequence tightening,diagonal tightening and simultaneous tightening these three tightening sequences on the deformation of the axle box.Moreover,we studied the influence of tightening times on the deformation of the axle box under the same preload.Then,we carried out the tightening experiment ofthe axle box bolt group and verified the simulation results to obtain the tightening sequence of the bolt group to minimize the deformation of the axle box bearing hole.