抽象的

CHATTER DETECTION OF BORING BARS

Nitin Elish Daniel , Subrahmanya Swamy

Boring, also called internal turning, is used to increase the internal diameter of the hole. During most deep hole boring operations —4× length to diameter and greater—the enemy is chatter. It seems to show up sporadically, and the deeper the bore the worse it can be. Chatter results from vibration between the tool tip and workpiece interface. It is further increased by deep hole boring because as the length to diameter ratio of the boring bar increases. Thus, instead of smoothly lifting and breaking a chip, the tool tip vibrates, causing the chatter to appear on the workpiece surface. This is bad for jobs requiring tight dimensional accuracy. Here the resonating peaks and the mode shapes of the boring bar at these peaks have been found out. In this paper boring bars have been designed to exhibit chatter, and resonating peaks have been recognised, mode shapes at these peaks have been extracted