Optimization Of Milling Process For Aeronautical Aluminum Alloy Grid Structure

With the rapid development of the aerospace industry,the design requirements for reducing the weight and improving the processing effect are put forward for the design of large aircraft.The aluminum alloy grid structure is widely used in the case structure of large aircraft,with light mass and stable structure,which is widely used for the structure stiffness,stability and quality,for example,large aircraft fuselage panels and rocket fuel tank panels.Therefore,higher requirements for the quality and efficiency of the grille structure are put forward.In order to meet the urgent needs of the development of space and space industry,it is of great theoretical significance and applied value to carry out the research on the optimization of the processing technology of large grid structure for the purpose of raising the quality.The panel structure of large aircraft is often subjected to high pressure and high load.If the wall thickness of the grid wall is not uniform,it can easily lead to the stress concentration,which will destroy the grid structure and make it invalid,which causes the parts to be discarded directly,which greatly affects the safety performance and service life of the structure parts.Therefore,keeping uniform wall thickness and reducing machining error of wall thickness is one of the effective means to reduce the phenomenon of stress concentration.At the same time,the surface roughness of the side wall also has a direct influence on the service life of the parts.As the surface roughness becomes larger,the corrosion resistance of the parts is reduced,the stability of the workpiece is greatly reduced,and the service life of the workpiece is reduced.Therefore,the good surface quality of the side wall can effectively improve the corrosion resistance and high pressure resistance of the workpiece,and then improve the working stability of the workpiece and prolong the service life of the workpiece.Due to the high density distribution of the grid structure,the efficiency of the grid structure is low.With the wide application of grille structure,improving its machining efficiency is one of the problems that must be solved in the production of grille structure.The reinforcement structure in the grid structure is the same,and the grid structure is simplified in the research.In this paper,theoretical analysis shows that the machining deformation of side milling is mainly affected by the cutting area.Under the condition of constant cutting area,the influence of different axial and radial feed configurations on the machining error of sidewall thickness is hypothesized and tested.When the cutting area is changed,the single factor test of the radial feed is designed,and the influence of the different axial and radial feed configuration on the wall thickness machining error is obtained.According to these laws of influence,the selection of radial feed of side milling grille is guided to reduce the machining error of side wall thickness and make the wall thickness uniform.By analyzing the cutting parameters that affect the surface roughness of the side wall and the processing time,the empirical formula of the surface roughness of the side wall is solved by the combination of theoretical analysis and test verification,and the effectiveness of the empirical formula is verified.The influence of each parameter on the surface roughness of the two sides of the side wall and the optimal cutting parameters are analyzed.And the expression of the influence of the number of tool paths on the processing time is also solved.With the aim of improving quality and improving efficiency,the cutting parameters are selected with regard to surface quality and machining efficiency.In the finishing process of the side wall of the grille,due to the machining allowance,the thickness of the sidewall is different when the sides are processed.The machining deformation is not easy to occur on the side of the side wall,and the thinner side of the side is easy to be processed.Therefore,the cutting parameters are selected by different optimization targets.To ensure that the thickness of each side wall in the grille structure is the same,the path of tool path is planned to ensure uniform wall thickness of each side wall.The above research results have been tested and verified that the surface quality and processing efficiency of the grille structure have been improved.The machining error of the side wall thickness of the grid structure decreases to a certain extent and ensures a more uniform wall thickness.In the engineering,it provides a positive guiding significance for the actual production and processing.