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轴向振动钻削机理及其工艺效果实验研究
Study on Mechanism and Process Effect of Axial Vibration Drilling
【作者】 马利杰;
【导师】 王贵成;
【作者基本信息】 江苏大学 , 机械制造及其自动化, 2007, 博士
【摘要】 振动切削是集金属切削理论、材料科学理论、振动理论、控制理论等为一体的一种先进切削加工工艺方法,作为振动切削技术的一个分支——振动钻削技术(尤其是轴向振动钻削技术)以其独特的工艺效果,受到国内外机械工程专家和学者们的广泛关注。小孔钻削是钻削加工的难点之一,加工稳定性、断屑排屑、工艺效果已经成为小孔钻削所必须解决的关键问题。当前,小孔振动钻削的工艺效果已得到初步验证,但研究工作仍处于起步阶段,巨大的潜在价值急需探讨。本文主要以小孔轴向振动钻削为研究对象,对其运动学特性、动力学特性及减振机理、断屑排屑机理、工艺效果等进行了深入的研究。本论文的研究工作有:1.基于压电陶瓷的逆压电效应和压电致动器的工作原理,研制了一种用于小孔振动钻削的压电式轴向振动工作台,并对压电振动台的静态、动态输出特性及实际加工中的振动特性进行了测试和分析,结果表明:该振动装置完全可以用于小孔的振动钻削加工。2.对轴向振动钻削的运动学特性进行了系统地分析,深入揭示了轴向振动钻削的变厚切削、变速切削、变角切削和分离冲击特性,并进一步研究了振动参数对振动钻削运动学特性的影响规律。3.基于机械系统动力学理论,建立了麻花钻扭转、弯曲振动的动力学模型,在此基础上,对轴向振动钻削过程中钻头的扭转、弯曲特性进行了初步的探讨,从而初步揭示了轴向振动钻削“以振治振”提高工艺系统稳定性的实质。4.对分离型、不完全分离型以及零相位差振动钻削的断屑机理进行了深入系统地研究,阐述了分离型振动钻削的切屑尺寸的预测预报方法,并编制了相应的程序,绘制出钻削过程中切削刃的运动轨迹和切削厚度变化示意图。基于钻削加工的切屑运动学原理和振动减摩机理,研究了普通麻花钻轴向振动钻削时,不连续型切屑的排屑机理,并进行了相应的实验验证。5.针对不锈钢和硬铝的小孔普通钻削和振动钻削试验,对钻削过程中的切削力、钻头的磨损破损形式,以及内孔的出口毛刺、表面形貌、尺寸精度等问题进行了对比研究。6.开展了MQL技术在轴向振动钻削中的应用研究。本研究是国家自然科学基金项目“精密零件棱边的形成机理及其控制”(项目编号:50275066)的重要组成部分。本文的研究工作将进一步丰富和发展振动钻削理论,对于进一步发挥振动钻削的优势、促进该项技术的推广应用具有重要的理论价值和应用意义。
【Abstract】 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.