Research On The Design And Cutting Performance Of Revolving Cycloid Milling Cutter And Circular Side Blade Milling Cutter

Titanium alloy aeronautical structure is one of the important parts of aircraft.In the process of machining,the ratio of curved surface finish machining is very important and the efficiency is high.On the one hand,titanium alloy is one of the typical difficult materials to process,on the other hand,the ball milling cutter which is widely used in the surface finishing process is universal,but it is limited by the geometric shape,the specificity is weak,and the processing efficiency is difficult to improve.Therefore,in the process of machining titanium alloy aeronautical structural parts,there are generally problems such as low machining efficiency,serious tool wear,and difficult to guarantee the surface quality,which seriously restrict the processing quality and efficiency of such parts.In order to solve this problem,this paper has carried out research on the design and manufacture of revolving cycloid milling cutter and circular side blade milling cutter by using graphic method and analytical method respectively.Through milling test,the milling force,tool wear and surface quality of titanium alloy were studied by comparing revolving cycloid milling cutter with ball end milling cutter and circular side blade milling cutter with or without ultrasonic vibration by using the comparative method.The research contents include the following aspects:Firstly,according to the machining conditions of flat surface with small curvature in titanium alloy aviation structure parts,in order to impro ve the cutting performance of tool end teeth,combined with the geometric characteristics of revolving cycloid profile and surface meshing,a revolving cycloid milling cutter was proposed and designed.The mathematical models of the profile,cutting edge line and the front and back cutter surfaces of the end teeth are established by using the graphic method.The grinding modeling of revolving cycloidal milling cutter is carried out.The cutting-edge curve of the cutter and the grinding path equation of the front and back face of the end teeth are derived.Secondly,in order to improve the machining efficiency,the radius of cutter body is decoupled from the radius of main cutting area,and circular side blade milling cutter is proposed and designed for the machining of small and steep curvature surface of titanium alloy aviation structure parts.The mathematical models of the profile,cutting edge line,front and back face of the milling cutter with circular side blade milling cutter are established by analytical method.Based on the linear relationship between the increment of return angle and the increment of edge lead,the five-axis grinding path equation of the key structure of circular side blade milling cutter is derived.Then,the comparative experimental research on titanium alloy machining with revolving cycloid milling cutter and ball end milling cutter is carried out.The wear area of revolving cycloid milling cutter is shallower and wider than that of ball end milling cutter,and there is no "spoon" shaped wear concentration area of ball end milling cutter,which can significantly reduce the axial force,tangential force and axial tangential force ratio,and the cutting process is relatively stable.Under the condition of tool wear,the increase of cutting force is still slow,and relatively good surface quality can be obtained,which shows better cutting performance.The algorithm of tool path generation for NC machining curved surface with revolving cycloid milling cutter is derived by using section line tool path planning method.Finally,the relationship between tool and tool motion is studied when the axial ultrasonic vibration is applied to the circular side blade milling cutter.The structural characteristics of the circular side blade milling cutter determine that in the vibration cutting process,it not only produces intermittent cutting phenomenon,but also changes the cutting layer thickness at high frequency.In this paper,a comparative experimental study on machining titanium alloy with and without ultrasonic vibration was carried out.Due to the micro damage of material caused by stress wave,the intermittent cutting phenomenon and the change of cutting layer thickness,ultrasonic vibration can significantly reduce the cutting force,improve the tool life,and the chip is easy to differentiate and separate,and the plastic deformation degree is also significantly reduced.In this paper,the cutting experiments of flat surface and steep surface with small curvature are carried out by using revolving cycloid milling cutter and circular side blade milling cutter respectively.Compared with ball end milling cutter,revolving cycloid milling cutter has excellent end gear cutting performance,tool life and workpiece surface quality are significantly improved.However,by virtue of its obviously larger working radius,the machining efficiency of circular side blade milling cutter can be increased to 5.3 times of that of ball end milling cutter in the cutting condition of small curvature and steep surface.Therefore,the surface finish machining of titanium alloy aeronautical structure parts with the above two new surface machining tools can effectively improve the machining quality and efficiency.