高强度钢18Cr2Ni4WA超声椭圆振动深孔镗削技术的研究

发布时间：2019-04-28 11:31

【摘要】：航空航天等领域经常需要加工一些特殊用途的深孔。传统深孔镗削由于镗杆的长径比大,切削系统刚度较差,加工时镗杆容易产生振动,严重影响工件的加工精度和表面质量。超声椭圆振动切削可以减小切削力,提高切削系统稳定性,为提高深孔加工质量提供了可能性。本文针对高强度中合金渗碳钢18Cr2Ni4WA展开超声椭圆振动深孔镗削技术的研究。将超声椭圆振动切削应用于深孔镗削加工,减小镗削加工过程的振动,改善加工表面质量。文中首先针对不同类型超声振动切削加工的基本原理进行分析;通过有限元仿真软件ABAQUS/Explicit建立传统切削、一维超声振动切削和不同类型超声椭圆振动切削的有限元仿真模型,进行对比仿真分析,研究不同切削方式的切削特点。利用有限元法设计一款单激励超声椭圆振动深孔镗削装置,能够加工最小孔径为17mm,最大长径比达20的深孔。装置使用纵向换能器激励装置的弯曲振型模式,使刀尖产生纵弯耦合椭圆振动轨迹。通过模态分析对结构进行优化,对优化后的结构进行谐响应分析和瞬态分析,得到不同频率简谐电压作用下刀尖位置的稳态位移以及刀具的轨迹,初步验证设计方法的正确性和装置结构的合理性。对所设计的超声椭圆振动深孔镗削装置进行阻抗测试,获得装置的共振频率为22.43KHz,利用激光位移传感器测得镗杆输出振幅-电压的关系。依托本文设计的超声椭圆振动深孔镗削装置,对超声椭圆振动深孔镗削高强度中合金渗碳钢18Cr2Ni4WA的切削力、切削稳定性、表面粗糙度以及断屑效果展开了实验研究。实验结果表明,超声椭圆振动深孔镗削的切削力大幅度下降,镗杆的振动显著降低,表面粗糙度Ra值减小超过50%,具有较好的断屑效果。通过镗削实验获得了超声振幅、切削用量等工艺参数对超声椭圆振动深孔镗削的切削力、加工稳定性和表面粗糙度的影响规律。实验结果为超声椭圆振动深孔镗削18Cr2Ni4WA的工艺参数优选提供了依据。
[Abstract]:Aerospace and other fields often need to process some special purpose of deep holes. Because of the large ratio of length to diameter of boring bar, the stiffness of cutting system is poor, the boring bar is easy to vibrate during machining, which seriously affects the machining precision and surface quality of workpiece. Ultrasonic elliptical vibration cutting can reduce the cutting force and improve the stability of the cutting system, which provides the possibility to improve the quality of deep hole machining. In this paper, the ultrasonic elliptical vibration deep hole boring technology for high strength medium alloy Carburized carbon steel 18Cr2Ni4WA is studied. Ultrasonic elliptical vibration cutting is applied to deep hole boring to reduce the vibration of boring process and improve the surface quality. In this paper, the basic principles of different types of ultrasonic vibration cutting are firstly analyzed. The finite element simulation models of traditional cutting, one-dimensional ultrasonic vibration cutting and different types of ultrasonic elliptical vibration cutting are established by finite element simulation software ABAQUS/Explicit, and the cutting characteristics of different cutting modes are studied. A single excitation ultrasonic elliptical vibration deep hole boring device is designed by using the finite element method. It can process the deep hole with the minimum aperture of 17 mm and the maximum length diameter of Prida 20. The longitudinal transducer is used to excite the bending mode of the device, which causes the tool tip to produce the longitudinal and bending coupling elliptical vibration trajectory. The structure is optimized by modal analysis, the harmonic response analysis and transient analysis of the optimized structure are carried out, and the steady-state displacement of the tool tip position and the tool path under the action of harmonic voltage at different frequencies are obtained. The correctness of the design method and the rationality of the device structure are preliminarily verified. The impedance of the ultrasonic elliptical vibration deep hole boring device is tested. The resonance frequency of the device is 22.43kHz. The relationship between output amplitude and voltage of boring bar is measured by laser displacement sensor. Based on the ultrasonic elliptical vibration deep hole boring device designed in this paper, the cutting force, cutting stability, surface roughness and chip breaking effect of high strength medium alloy Carburizing steel 18Cr2Ni4WA are studied experimentally. The experimental results show that the cutting force of ultrasonic elliptical vibration deep hole boring is greatly reduced, the vibration of boring bar is significantly reduced, the surface roughness Ra is reduced by more than 50%, and the chip breaking effect is better. The effects of parameters such as ultrasonic amplitude and cutting parameters on the cutting force, machining stability and surface roughness of ultrasonic elliptical vibration deep hole boring are obtained by boring experiments. The experimental results provide a basis for optimizing the technological parameters of ultrasonic elliptical vibration deep hole boring 18Cr2Ni4WA.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG53
，

本文编号：2467591