Study On Parallel Milling Of Inner Threads With Small Spiral Rising Angle

With the rapid development of manufacturing industry,thread is widely used in various mechanical products.The quality of thread directly affects the safe and stable operation of mechanical equipment,so it puts forward higher requirements for thread processing.The special-shaped internal thread is affected by its workpiece structure and the particularity of thread tooth shape.The traditional turning and tapping methods have the problems of clamping difficulty,low efficiency,low precision,easy damage of cutting tool and high processing cost,which greatly limit the production and application of special-shaped internal thread.thread milling method is an advanced processing technology.parallel milling of internal thread is a form of milling internal thread.compared with other thread processing technology,it has the advantages of convenient clamping,good processing quality and high processing efficiency.it can effectively replace the traditional thread processing method.However,due to the principle error of parallel milling,there is no complete theory for the determination of machining process,the design of milling tools,the selection of milling parameters,etc.,so it has not been widely used.In this paper,a special-shaped internal thread milling technology and tool design research,including the following five aspects:(1)The principle of parallel milling of special-shaped internal thread is analyzed,and the causes of over-cutting error and surface roughness are analyzed theoretically.(2)Compare the advantages and disadvantages of thread milling cutter and select the appropriate type of thread milling cutter,analyze the machining process of parallel milling of special-shaped internal thread,and write the NC machining program of parallel milling of special-shaped internal thread.(3)Analyzes the influence of the diameter of the cutter rod on machining,calculates the diameter of the cutter rod,and makes a static analysis of the cutter rod through Ansys finite element simulation software to verify whether its stiffness meets the machining requirements.(4)Analyse the influence of cutting tool profile and cutting tool front and rear angle on machining,select reasonable cutting tool front and rear angle,design blade profile shape,select suitable blade material and coating.(5)The influence of cutting three elements on surface roughness was studied by orthogonal experiment.The diameter of thread arc contour and the surface roughness of thread arc were measured by roughness meter.The experimental results are analyzed to verify the rationality of the designed tool contour shape,to determine the influence of each factor on the surface roughness,and to carry out single factor optimization experiments on the factors that have the greatest influence on the surface roughness.Select the most reasonable combination of cutting parameters within the scope of study.