Research On Finishing Theory Of Equal Base Circle Bevel Gear Based On Ball End Milling Cutter

Equal base circle bevel gear is a new type of curved bevel gear processed by forming method,which has the advantages of strong bearing capacity and low processing cost,and can be widely used in the field of mechanical transmission.The traditional machining method is use to the finger-shaped milling cutter as the cutting tool to the copy machining this kind of gear.But because of the limitations of the manufacturing technology of the finger-shaped milling cutter,it is necessary to rely on the template to ensure the accuracy of the cutting tool section curve,which is difficult to guarantee the tooth surface precision and tooth shape precision of the gear after machining.This will greatly affect the manufacturing accuracy of equal base circle bevel gear and limit the popularization and application of the new curved bevel gears.In this paper,equal base circle bevel gear is taken as the research object.In order to improve the precision of tooth surface and tooth shape of equal base circle bevel gear,on the basis of the existing processing theory of forming method,the processing scheme of "rough machining of finger-shaped milling cutter and finish machining of ball-end milling cutter" is put forward.The coarse and finish machining theory and machining method of the equivalent base bevel gear of the system are studied.The specific contents are as follows:Rough machining path planning and calculation based on finger-shaped milling cutter.In order to obtain the surface with uniform allowance and close to the theoretical tooth surface shape after rough machining,the forming method of fingershaped milling cutter is used to rough the base bevel gears First of all,we analyze the feasibility of using finger-shaped milling cutter to rough machining the equal base circle bevel gear,and establish the gear cutting coordinate system.Then,the normal vector of tooth surface is solved,and based on this,the rough machining tool path of finger-shaped milling cutter will be planned.By solving the cutter center coordinate and the cutter axis vector,and combining with the numerical control post-processing,we can deduce the expression of the machine tool's motion coordinate and rotation Angle when using the finger milling cutter to rough process this kind of gear.It can realize the rough machining of the tooth surface of the equal base circle bevel gear and lay a foundation for the subsequent finish machining of the equal base circle bevel gear with the ball end milling cutter.Finish machining path planning and calculation based on ball end milling cutter.According to the theory of equal base circle bevel gear tooth surface forming,the equidistant surface equation of the theoretical tooth surface of equal base circle bevel gear is derived.From the Angle of machining allowance and cutting tool performance,we have planned the tool path of finish machining on the theoretical equidistant tooth surface and the cutter center coordinates of the ball end milling cutter are obtained by combining the theoretical equation of the equally spaced tooth surface and the planned tool path.By means of post processing technology,the cutter center coordinates are transformed into the machine tool motion coordinates which can be used for NC machining.Finally,through the analysis of the finishing process,the calculation method of the optimum row spacing and step spacing for the ball end milling cutter with equal base circle bevel gear is deduced.On the basis of ensuring the machining accuracy and smoothness of the tooth surface,the machining efficiency is improved and the machining cost is reduced.Simulation machining and experimental verification of equal base circle bevel gear.Firstly,in UG software,the standard gear is modeled using the discrete point data generated by the tooth surface equation of equal base circle bevel gear.And then rough and finish machine model is built in VERICUT software,and the finger-shaped milling cutter model,ball end milling cutter model and gear billet model are built in the simulation environment.The tool path of roughing and finishing that was generated before is written into a NC program that can be used for rough machining and finish machining.Then equal base circle bevel gear machining simulation and rough and finish machining tooth surface error analysis are carried out.Finally,equal base circle bevel gear machining experiment and gear rolling detection experiment are carried out.The correctness of rough machining theory with finger-shaped milling cutter and finish machining theory with ball end milling cutter are verified by experiment,and verify the rationality of the corresponding numerical control machining method.