Study On The Deep-hole Axis Deviation Based On The Mechanism Of Self-directing

In the field of modern deep-hole processing,more and more high-precision,high-quality deep-hole processing.there is a major problem that has always plagued the deep-hole processing manufacturing——deep hole drilling in the hole axis deflection.There are many factors affecting the deflection of the deep hole axis,such as the geometry and position parameters of the guide bar,the blade geometry parameters,the bending of the drill pipe,etc.,but in the end they all exert influence through acting on the guide pair.Therefore,based on the mechanism of the self-directing pair,establishing a mathematical model to study the axis deviation of the deep hole has practical significance for the study of the theory of deep hole deflection and the guidance of cutting processing.Self-guided means that deep-hole cutters do not rely on external guide positioning devices.They rely on their own guide pairs to achieve the guiding effect in the cutting process.Based on the self-guided mechanism,this paper analyzes the stress state of the self-guided tool and establishes the mechanical model of the guide pair.Based on this model,the equivalent load theory for studying the secondary force state of the guide is proposed,and its theoretical load form is analyzed.Based on the theory of elastic-plastic combined deformation and Hertz's line contact theory,the actual contact width coefficient was introduced and the mathematical model for the self-guided deep hole tool axis deflection was established.Secondly,deep-hole machining cutting experiments were carried out to compare the theoretical deflection data calculated with the axis deflection model under different load situations with the actual deflection data.This verifies the reliability of the theoretical model and determines the working state of the leading pair in the actual cutting process.Then,based on the validated theoretical model of axial deflection,the influence of the amount of lag in the guide strip on the deflection of the secondary guide and the axis deviation was studied.The influence of the length of the guide strip and the workpiece material on the axis deflection was obtained,Come to the conclusion that the guiding significance.Finally,the mechanical relationship between the tool head and the drill pipe axis direction is analyzed.The quadrants of the radial force component produced by the bending of the drill pipe are divided and limited discussion,and then the mathematical model for the study of the effect of drill pipe bending on the axis deflection is established.Based on the above model,the effect of drill pipe bending on deflection of the guide bar and the effect of drill pipe bending on the total axial deflection were studied.