The Research Of Specific Cam NC Machining Technology

With the development of new materials and new process, all kinds of advanced manufacture technology have been applied widely, so cam design and manufacture will be verily convenient and precise, and cam production cost will also be reduced. Especially, with the development of computer, Computer-Aided design and Computer-aided Manufacture are applied to cam mechanism, as a result, computer technique improve the quality and speed of cam design and manufacture, that creates good conditions for cam mechanism's widespread use, then promote automatic mechanism's development preferably.By analyzing the feature of cam's contour line, this paper proposes a machining solution of cam, and reasizes digital control processing about cam in Polar Coordinate by controling rotary motion and linear motion. It is easy to design cam's contour line by utilizing angle and radius in Polar Coordinate. This plan avoids the conversion of Polar Coordinate and Rectangular Coordinate,and interpolates cam's contour line by control rotary motion and linear motion. The algorithm of interpolation is data sampling interpolation, which judges axial direction and calculates axial incremental motion. Moreover, this paper also analyses the error of interpolation, and gives methods to control the error of interpolation, so makes every step interpolation always meat accuracy requirement.This paper designs control system too, which adopts combine mode of upper computer and lower computer. It makes use of PC's powerful software and hardware function, to calculate interpolation of cam's contour line, then obtains coordinates of nodal point and interpolation step size and so on,and conveys the information to PLC. Lastly, PLC controls actuating motor to move until finish machining. Because of coordinated control in the course of machining, this paper chooses FM357 as the positioning module, which controls four axis at the same time, so it meats system need.Finally, this paper amends equations of every law of motion becomingly, according to usual law of motion of cam outline curve, in order to meet the need of smooth transition, and writes generator programs of cam outline curve, then generates designed cam outline curve model, by using drawing function of MATLAB. Once having mathematical models of cam outline curve, then MATLAB can simulate the interpolation algorithm of cam outline curve, by using algorithm develop and math calculate capability of MATLAB. This paper compiles interpolation procedures, and controls real-time interpolation errors, then realizes dynamic simulation of cam's contour line by using drawing function of MATLAB, and confirms feasibility of interpolation algorithm, besides, this paper also checkes validity of interpolation algorithm, by analyzing the interpolation results. In addition, this paper chooses VB to develop application software for PC, and designs interface of interpolation simulation, and compiles interface program of VB and MATLAB, as well as VB and PLC.