Study Of Non-equant Machining With Five-axis NC Machine And Profile Correction Of Globoidal Indexing Cams

Globoidal indexing cam mechanism is a kind of intermittent motion mechanism,which is widely used in the occasion of high speed and high precision, it turned out a good performance in the high-speed occasion. The contour surface of globoidal indexing cam is complex, which is very difficult to design and process, especially in processing. Processing is a prominent obstacles in the application of globoidal indexing cam mechanisms.Considering the existing problems that lie in the machining of globoidal indexing cam, non-equant NC machining of globoidal indexing cams have been deeply researched. Based on the conjugate engagement theory of globoidal indexing cam mechanism, non-equant NC machining of globoidal indexing cams have been discussed. The parametric equations of actual cutting surface have been derived. Then the non-equant machining method that offset at the midpoint was proposed, and control formulas of machining tool was deduced. At the same time, profile correction of globoidal indexing cam has been researched, and come up with a set of appropriate profile correction scheme. Finally, developed a globoidal indexing cam CAD/CAM system.Through the analysis of the meshing principle of globoidal indexing cam, combined with the structure characteristics of the five axis CNC machine, control formulas of machining tool was deduced by the method of coordinate transformation, which is used in the equivalent machining of globoidal indexing cam on five-axis CNC machine. The offset direction and size of tools was deduced according to the principle of cutter location compensation method, and finally deduced the control formulas in non-equant machining of globoidal indexing cam by five-axis CNC machine. It can be programmed to calculate the machining data of the cam, and realize the non-equant machining of globoidal indexing cam by five-axis CNC machine.On the basis of the conjugate engagement theory of globoidal indexing cam mechanism, a kind of profile modification method of globoidal indexing cam has been put forward based on traditional generating method. By the modification of the trajectory of cutting tools in the engaging-in and engaging-out section and cut more of the corresponding areas in the dwell region to modify the cam’s profile. Moreover, modification program of different types of globoidal indexing cam are presented, providing a theoretical basis for the machining of globoidal indexing cam’s modification.Finally, by using VB6.0 and the object-oriented programming method, adopting modularity design theory, developed the CAD/CAM system of globoidal indexing cam, which can help to design globoidal indexing cam rapidly, and will significant improve the design efficiency, shorten the development time.