Fig。 8。    A typical measurement result of the cutting force pattern with continuing change of the tool inclination   angle。

Fig。 9。    Cutting force patterns with inclination angles for different tool   inserts。

4。 Conclusions

With the prospective open-architecture controllers, active control of the on-line machining pro- cess performance will become a very important feature of advanced CNC machine functions, allowing both the tool path and the process performance to be programmed and controlled in real-time CNC machining operations。 Therefore, the object of this work is to develop a new tooling mechanism with on-line adjustable tool angles to take full advantage of new-generation CNC machines which will be equipped with open-architecture control systems。 In effect, an on- line controllable tooling mechanism will be the ‘real sense’ application of open-architecture CNC control systems。

Tool inclination angle is a major tool geometry parameter in machining and has a significant effect on a number of process performance parameters, such as cutting forces, surface quality, chip flow and formation, process dynamic stability, tool wear/tool life, etc。 Thus it is important that the tool inclination angle could be adjusted and controlled in real-time to achieve the optimal machining performance in unattended CNC machining  processes。

A motor-controlled toolholder that can be used in CNC machines has been developed with the function of automatic setting of the tool inclination angle and automatic compensation of the resulting tooltip deviations。 The new CNC tooling mechanism is a novel design using three curved slots that work simultaneously to compensate continuously and accurately the tooltip deviations resulted from the setting of the tool inclination angle。 Since the tooltip always stays at one point in space, i。e。 its working point, during the whole adjustment process of the required tool inclination angle, the new tooling mechanism could be used in real-time CNC machining operations to achi- eve the on-line control of optimal process   performance。

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