【摘要】：航空航天等領域經(jīng)常需要加工一些特殊用途的深孔。傳統(tǒng)深孔鏜削由于鏜桿的長徑比大,切削系統(tǒng)剛度較差,加工時鏜桿容易產(chǎn)生振動,嚴重影響工件的加工精度和表面質量。超聲橢圓振動切削可以減小切削力,提高切削系統(tǒng)穩(wěn)定性,為提高深孔加工質量提供了可能性。本文針對高強度中合金滲碳鋼18Cr2Ni4WA展開超聲橢圓振動深孔鏜削技術的研究。將超聲橢圓振動切削應用于深孔鏜削加工,減小鏜削加工過程的振動,改善加工表面質量。文中首先針對不同類型超聲振動切削加工的基本原理進行分析;通過有限元仿真軟件ABAQUS/Explicit建立傳統(tǒng)切削、一維超聲振動切削和不同類型超聲橢圓振動切削的有限元仿真模型,進行對比仿真分析,研究不同切削方式的切削特點。利用有限元法設計一款單激勵超聲橢圓振動深孔鏜削裝置,能夠加工最小孔徑為17mm,最大長徑比達20的深孔。裝置使用縱向換能器激勵裝置的彎曲振型模式,使刀尖產(chǎn)生縱彎耦合橢圓振動軌跡。通過模態(tài)分析對結構進行優(yōu)化,對優(yōu)化后的結構進行諧響應分析和瞬態(tài)分析,得到不同頻率簡諧電壓作用下刀尖位置的穩(wěn)態(tài)位移以及刀具的軌跡,初步驗證設計方法的正確性和裝置結構的合理性。對所設計的超聲橢圓振動深孔鏜削裝置進行阻抗測試,獲得裝置的共振頻率為22.43KHz,利用激光位移傳感器測得鏜桿輸出振幅-電壓的關系。依托本文設計的超聲橢圓振動深孔鏜削裝置,對超聲橢圓振動深孔鏜削高強度中合金滲碳鋼18Cr2Ni4WA的切削力、切削穩(wěn)定性、表面粗糙度以及斷屑效果展開了實驗研究。實驗結果表明,超聲橢圓振動深孔鏜削的切削力大幅度下降,鏜桿的振動顯著降低,表面粗糙度Ra值減小超過50%,具有較好的斷屑效果。通過鏜削實驗獲得了超聲振幅、切削用量等工藝參數(shù)對超聲橢圓振動深孔鏜削的切削力、加工穩(wěn)定性和表面粗糙度的影響規(guī)律。實驗結果為超聲橢圓振動深孔鏜削18Cr2Ni4WA的工藝參數(shù)優(yōu)選提供了依據(jù)。
[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.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG53
，

本文編號：2467591