Research On Optimization Design Of Deep Hole Tool Based On Precision Guidance

With the development of the national economy,there are more demands for deep-hole parts in various fields of industry and military industry.At the same time,higher requirements are placed on the processing quality of deep-holes.One of the main control factors is the straightness of the hole axis.The problem of deep hole axis deflection has always been the focus and difficulty of the research.The factors affecting the axis skew are various,and the deep hole tool is responsible for cutting and guiding during machining,which plays a vital role in the processing quality.Based on the modern deep hole technology of the self-guided mechanism,the most important problem is the deep hole tool.In this paper,by analyzing the elastoplastic deformation of the guide pair and the axial deflection of the deep hole,the influencing factors of the tool system are studied and an optimization scheme is proposed to improve the quality of deep hole machining and solve the problem of axis skew.This has important theoretical and practical significance for improving the level of deep hole processing and developing deep hole equipment.Firstly,the characteristics of the self-guided tool and the axis deviation of the machined hole are analyzed.From the perspective of the tool in the deep hole equipment,the influence of the tool structure and its geometric parameters on the stress state of the drill bit and the machining quality of the hole is analyzed.Point out the design points of the deep hole tool and the theory and experience range of each parameter under the requirements of precise guidance.Second,analyze and calculate the force the tool is subjected to during the machining process.The equivalent contact model of the guide pair is established and the load model on the guide strip is analyzed.The guide pair contact is equivalent to the finite long line contact for analysis.The elastoplastic deformation and other related theories are used to establish the calculation formula of the deflection of the deep hole axis,and the relationship between the parameters of the deep hole bit and the unit deflection of the hole axis is obtained.The obtained skew calculation formula is verified and corrected by actual machining.Then,the force of the BTA single tooth drill and the wrong tooth drill,the deformation amount of the guide bar and the axial unit deflection amount of the machined hole are analyzed and compared.The key factors affecting the deflection of the deep hole axis are analyzed from the influence of the difference of the structure on the deflection of the machining hole axis.Finally,according to the design of the possible smaller axis deviation obtained by the analysis,the number of the guide bars,the length,the width,the hysteresis of the guide bar,the residual angle of the blade,the working width of the blade,and the like are respectively changed.Obtain the calculated value of the theoretical axis skew and compare and analyze to obtain reasonable optimization design parameters.