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In order to obtain higher cam quality, the research on the cam contour error is studied. The cam is machined in the way of X-C biaxial linkage motions. The linear motor drives the grinding wheel mechanism to get the motion of X axis, and the motion of C axis is the rotating of cam driven by the torque motor. Because of the servo-system-lag of the two axes, the cam contour error is formed in the X-C biaxial linkage motions. Moreover, the following position error of X axis and C axis is not same as the cam contour error. The relationship between axis following position error and cam contour error is studied. The mathematical model of cam contour error is constructed, the relationship between the cam contour error and the following position error are obtained. At last, the conclusion which the cam contour error can be controlled is made, although the following position error exists at the same time. To design the contour error controller for higher quality cam is based on the above conclusion.

Composite grinding machine for non-circular shaft parts, on the workpiece servo spindle high requirements.In order to overcome the vector control coordinate calculation of complex, slow response speed and other defects, this paper adopts the direct torque control scheme of asynchronous motor spindle servo control research.Using the Matlab/Simulink module library provides the basic module, built asynchronous electric spindle direct torque control system model.Coordinate transformation process were established, flux adjust step, flux observation, link and loop PID position control module, and the use of subsystem package technology package.The current loop, speed loop, ring in position and torque simulation test, the results show that, the method of direct torque control of asynchronous motor spindle control drive control system can obtain good static and dynamic response characteristics and the closed-loop response performance.

With the development of auto industry, the cam quality requirements higher and higher. In order to illustrate the effect of servo lag upon cam Contour error, X-C servo axis Trajectory coordinates have been acquired in real-time with dual-channel mode during cam grinding. By comparing the Trajectory coordinates detected and the interpolation contour, the errors caused by servo feed lags were verified, and the mechanism that how axis feed acceleration impact on cam Contour errors was proposed. Based on data acquisition and product test, the error compensation method based on servo lag is proved reasonable.

Used fixed equal step cubic spline interpolation in non-circular machining, the influence of acceleration may be too strong to cause burns and vibration. To suppress the acceleration influence of feed axis, take cam grinding as an illustration, first derived acceleration and its change from the cubic spline function, then adopting the method of off-line fuzzy model logical reasoning combined with five points of three power smooth, obtained the modified variable interpolation time steps. The experiment results that the feed axis acceleration stability used fuzzy step cubic spline interpolations is much better than equal step spline in cam grinding under the same processing efficiency.

As the key parts of cars, camshafts influences a lot on the quality and durability of cars. Their processing is complicated, time and place consuming and the quality is difficult to guarantee. The turning-grinding composite machine tool (TGCM) for camshafts is studied on basis of ‘process integration with one setup’ theory in this paper. It presents the structure of the turning-grinding composite machine tool by the analysis of the function of TGCM. The revolving working table is used to transfer the turning and grinding function. It also discusses the constant grinding removal rate mathematic model of the cam contour machining. The opened-CNC system for this machine tool is developed by using the VC++6.0 based on PC and UMAC controller. The constant grinding rate model of the cam contour is verified by the experiment results.