Formation and control of burrs in precision machining
The existence of the metal cutting burr not only reduces the dimension and shape accuracy of the workpiece, but also increases the manufacturing cost. Currently, the burr has been the most troublesome obstruction to high productivity and automation of machining processes. In this paper, the hazard of the burrs is systematically discussed in the precision or ultra-precision machining firstly and then, the formation principle and morphology of burrs in precision turning, planing, drilling and milling are studied. Finally many new technologies and methods of restraining or decreasing burrs have been developed by the cutting experiments.
Development of Drill Geometry for Burr Minimization In Drilling
Abstract The researchers carried out drilling tests using drills of various shapes to determine burr minimization. The ultimate objective of this study was to develop a compatible drill shape to minimize burr formation. For the experiment general carbide drills, round drills, chamfer drills and step drills are designed and manufactured. Burrs are generated under various cutting conditions using four different materials. A laser sensor was used to measure the burr dimensions. As a result of the experiments, step drill with specific step angle and step size Is suggested for burr minimization.
Study on Oscillatory Drilling Aiming at Prevention of Burr.
Burr in drilling operations has been a serious problem especially in the area of factory automation and high technology. In order to prevent burr in drilling operations ultrasonic or low frequency vibration has been applied in the direction of drill feed. In this study in order to enhance the effect of oscillation in drilling operations newly developed “radial peripheral lip drill” has been applied as well as the standard type of drill. With the radial peripheral lip drill the radial lip at the corner of drill edge is able to obliquely cut and sharply slice the stock at the hole exit, which would become burr, by the aid of oscillatory motions in the direction of drill feed. Low frequency vibration is as highly effective in preventing burr as ultrasonic vibration except that the former is effective only with the radial peripheral lip drill.