A Study on Burr Formation and Controlling Technology in Precision or Ultra-Precision Drilling

Burr formation is a common phenomena in metal cutting. The burr not only effect precision of parts directly but influence the assembly quality badly. Therefore, the control and deburring technology of machining burrs has become one of the key problem in precision or ultra-precision and automatic procession. In traditional drilling, the exit burr is bigger than the entrance burr, and its hazard is more larger. Moreover deburring process is very complex. According to these status quo, a new method of active control of the exit burr is put forward using vibration drilling. Mechanism of chip broken and burr formation in vibration drilling are analysed systematically and an equipment of vibration drilling is developed based on drilling experiment. Cutting test on A3 material, brass (H62) and 1Cr18Ni9Ti stainless steel is carried out using the method of vibration drilling. As a result, cutting character is improved because of the using of this method. Also, machining accuracy and surface integrality of parts are improved remarkably and the size of the exit burr is controlled effectively in vibration drilling. The development of vibration drilling device provides a new approach for the progress of ultra-precision drilling technology. Vibration drilling device and technology developed in this study can be widely used to ultra-precision machining.