Research On Machine Tools Subsystem Vibration In Large Pitch Thread Cutting

Large-pitch screw is widely used in large-scale equipment as a key part and plays a role in connection,fastening,and transmission of power.The use of medium-and small-pitch technology in production results in a multiple increase in cutting forces.At the same time,due to its large ratio of length to diameter,the vibration of the processing system is severe,and it is difficult to ensure high-quality machining of large pitch long thread strokes.At present,there are few studies on the vibration characteristics of the process system.In the processing of large-pitch thread,the machine tool subsystem is an important part of the machining process system.The study of the vibration characteristics of the machine tool system in the machining system has become a major thread pitch processing.The basis of vibration research in process systems.In this dissertation,from the perspective of the space of large-pitch thread processing system,the relationship between the spindle of the machine tool subsystem and the action of the feed screw on the tool is studied through the process of finishing the large-pitch thread in the finishing process,and the vibration of the spindle to the workpiece is stimulated.The excitation of the screw on the tool vibration is used as the output end to study the spindle vibration and the screw vibration of the machine tool.At the same time,the interaction between the spindle and the screw vibration is studied to obtain the vibration characteristics of the machine tool subsystem in the process system.Firstly,the dynamics model of the machine tool spindle is established,the dynamics of the machine tool spindle is analyzed,the mode vibration function of the machine tool spindle is determined,and the multi-order vibration frequency and the maximum deformation of the machine tool spindle are simulated using ANSYS software to obtain the multi-mode of the machine tool spindle.State mode shape,modal analysis of the main shaft.Secondly,the vibration of the feed screw of the lathe feed system is studied.The contact between the table and the screw is simplified as the joint surface.The model of the joint surface is established.The transverse vibration,longitudinal vibration and torsional vibration of the screw of the feed system are analyzed and the screw is established.The longitudinal,torsional,and transverse vibration functions of the machine were derived and the dynamic equations of the feed screw of the machine tool feed system were derived.Then,the large-pitch thread finishing vibration test experiment was planned,and the machine tool spindle and screw vibration test platform were set up to obtain the vibration signals of the machine tool spindle and screw under various working conditions,and the signals were subjected to signal Fourier transformation and filter processing.The vibration characteristic parameters were extracted,and the vibration characteristics recognition method of spindle vibration and screw vibration of the machine tool was proposed to realize the vibration recognition of the spindle and the screw.Finally,a large-pitch thread finishing experiment under various cutting parameters was performed to verify the large-pitch machining vibration identification method established in this paper.The machine spindle vibration signal and the screw vibration signal under left and right cutting edges were detected,and the vibration recognition method was used to identify the finishing state.Different vibrations of spindle vibration and screw vibration were analyzed.The vibration conditions of spindle and screw under different parameters were analyzed.The interaction between spindle vibration and screw vibration in machining process was revealed,and the vibration acceleration equation of the machine tool was established.This dissertation analyzes the modal simulation of the spindle of the machine tool,analyzes the vibration of the screw,and analyzes the experimental data of the large-pitch thread finishing vibration,which provides the basis for the analysis of the vibration of the machine tool subsystem in the processing of large-pitch thread.At the same time,it provides theoretical guidance for the actual processing of large pitch threads.