Study On Mechanism And Process Effect Of Axial Vibration Drilling

Vibration cutting is a kind of advanced machining technology that utilizes much knowledge such as metal cutting theory, materials science, vibration theory, control engineering etc. Vibration drilling is a branch of vibration cutting. Because of its unique process effect, vibration drilling, especially axial vibration drilling, has been noticing widely by many specialists and scholars.The machining of small hole is one of difficulty of drilling and the key problem of machining small hole is chip-breaking, chip-removing, machining stability and process effect. At present, the process effect of machining small hole by vibration drilling has been verified firstly. But the research about this aspect is just begun and there are some problems that need be solved quickly. Therefore, based on vibration drilling of small hole, the author studied deeply kinematics characteristics, dynamic characteristics, chip-breaking, chip-removing and process effect of axial vibration drilling. The creative work and research content of this paper is mainly as follows:1. Based on converse piezoelectric effect of piezoelectric ceramics and basic principle of piezoelectric actuator, we had developed a kind of piezoelectric vibrating table that can be used to axial vibration drilling. And then its actual output and operating characteristic are tested and analyzed. The result shows that piezoelectric vibrating table can be used as vibration equipment of machining small hole.2. The four kinematics characteristics of axial vibration drilling are analyzed. The influence of vibration parameters on kinematics characteristics is disclosed.3. According to the dynamic theory of mechanical system, we built the bend and torsion vibration model of the twist drill and analyzed the bend and torsion vibration rules of drill in vibration drilling. So, the essential of decreasing vibration of vibration drilling is primarily opened out.4. We expounded mechanism of chip-breaking and the predictive method of chip dimension of separate vibration drilling. By computer program, the diagrammatic sketch of the cutting locus and the cutting thickness of axial vibration drilling are plotted. The mechanism of chip-breaking of incomplete-separate vibration drilling and zero-phase-difference vibration drilling is studied. According to chip moving principle and vibration antifriction effect, the removing mechanism of discontinuous chip is analyzed.5. According to experiments of common drilling and vibration drilling of small hole on stainless steel (0Cr18Ni9) and duralumin (2A12), the cutting force, cutting-tool wear, surface topography, dimensional accuracy and exit burr are observed and studied in drilling.6. The research of application of MQL on vibration drilling has been developed. This research is an important part of national natural sciences fund project(No.50275066). The working achievement of this paper will riches and develops the theory of vibration drilling. It has high theoretical and applied value in prompting the application and development of this technique.