Research On Cutting Technology Of Thin Wall Weak Rigid Intermediate Box Foundation Of New Transmission System

The thin-walled complex structure box represented by the middle box is an important part of the new transmission system.Its processing accuracy restricts the improvement of the transmission system performance and directly affects the performance of a certain type of special vehicle and other key technical indicators.The overall quality of a certain type of special vehicle has a huge impact.In this paper,the basic cutting characteristics of the box material ZAL114 high-strength aluminum alloy are studied.Through process cutting optimization and static analysis under box cutting load,combined with systematic research in cutting machining vibration test and box surface residual stress analysis,the machining accuracy of the weakly rigid intermediate box is significantly improved,and the box end face is optimized.And the process control ability of the box body’s multi-type hole axial runout has improved the stability and reliability of the processing quality of the middle box body.The combination of cutting parameters obtained in this research is:feed rate f=0.1mm/r,back-cutting amount(cutting depth)ap=0.5mm,and cutting speed vc=300m/min.Under this cutting parameter combination condition,the steady-state cutting force in the X direction is 120N,the steady-state cutting force in the Y-direction is 80N,and the steady-state cutting temperature is 261℃.Through static analysis under static load,the parameter combination of the optimal milling plane is obtained.The rotation speed is n=4000r/min,the cutting amount per tooth fz=0.25mm/z,the radial depth of cut ae=5mm,and the axial depth of cut ap=3mm.Under the guidance of the optimized process obtained in this article,the processing accuracy of the intermediate box body meets the requirements of the design drawing,and the processing efficiency is increased by 20%;the measurement result of the outer circle size tolerance of the intermediate box body shows that the optimized process size error is 0.036mm,which is less than the drawing requirements 0.04mm,which is higher than the original process size error of 0.076mm;the upper and lower end faces and the spigot of the box have a coaxiality of Φ0.04mm.The optimized process processing coaxiality error is 0.041mm,which is better than the original process coaxiality error The measurement result is 0.096mm,and the detection result of the maximum residual stress of the middle box with the end face machining surface is close to the stress value of 131.4Mpa obtained by the Abaqus cutting simulation,which proves that the simulation model is consistent with the actual machining situation.The test results meet the technical requirements of the drawings.