Machining Accuracy Consistency Of Long Pitch Thread In Turning And Cutting Tool Structure Stability

Long pitch thread which used as key parts of automobile covering parts nuclear power and other pieces of heavy equipment, plays the role of transmitting torque and displacement. Heavy-duty equipment working performance influenced by large pitch thread accuracy consistency. At the same time long pitch thread belongs to parts of non-standard parts and has long screw pitch, tooth type groove width and depth, big allowance, heavy load, cutting vibration, seriously wear of tool, poor retentively of edge shape. Therefore accuracy consistency of the long pitch thread and tool structure stability is the problems need be solved in development and application of heavy equipment key parts. At present, the research concerning the stability of cutting tool structure influence on machining accuracy of long pitch thread mainly concentrated on a single precision index, no analysis of long pitch thread accuracy consistency.In this paper on the basis of existing research results about machining precision, In order to control long pitch thread accuracy consistency, design tool structure stability. Using mathematical statistical errors analysis, cutting deformation and wear theory, grey relation method for the study on design method of long thread accuracy consistency and tool structure stability.According to the turning long pitch thread machining precision consistency without quantitative characterization and evaluation, on the basis of the characterization of the error distribution, using the mathematical statistics theory of error analysis, established consistency evaluation method of large pitch thread accuracy, through the thread surface point extracting and facial features precision calculation, analysis by experiment on the thread surface processing precision consistent.In order to reveal the effect of deformation characteristics on contour curvature precision consistent, established thread cutting tool set up layer and unit cutting load model, according to the effects of structure parameters and cutting parameters on cutting edge bias, further access effect characteristics of cutting edge on contour curvature, through the cutter deformation experiment obtain comparison between simulation and experimental results, experimental verification the impact characteristics of the deformation of the tool on the thread surface machining accuracy consistent.In view of serious tool wear in long pitch thread turning process, affects cutting stability problem, considered from the rough machining in turning process, the experiments on the evolution analysis of the wear, obtain its wear characteristics and structural parameters as the boundary condition of thermal coupling field analysis, get the prediction model of force and heat, finally establish a long pitch thread wear process control method and experimental verification.In order to realize the control of tool structure stability and the thread surface machining accuracy consistency, according to the comparison between experiment and actual processing results, preferably a cutter body, established relevance model of tip displacement and position vector precision and bias and precision cutting edge direction vector, get the design method of clamping structure, establish association model of tool flank wear position vector accuracy, further on the basis of finishing the thread experiment obtain design method of long pitch thread cutter edge and validated by experiments.