| NOMEX honeycomb composites have been widely used in aerospace and other fields because of their excellent properties,such as high specific strength and specific stiffness.However,for the processing of honeycomb composites,a large number of machine tool manufacturers abroad have developed ultrasonic cutting equipment,which has been widely used in aerospace manufacturing enterprises,and has high quality and efficiency.But in China,it is also limited to traditional high speed milling.The quality and efficiency of machining are not good.A lot of dust will cause environmental problems,and it is difficult to adapt to the requirements of aerospace industry.Besides,the purchase price of ultrasonic cutting machine in China is very expensive,and it is also restricted by foreign machine tool manufacturers in terms of equipment usage and maintenance,which is very unfavorable for the development of China's aerospace industry.Therefore,the independent research and development of ultrasonic cutting machine and related equipment to achieve the localization of honeycomb composite ultrasonic cutting equipment and improve the manufacturing level of special processing equipment in China is of great significance.Aiming at the above problems,this paper carried out the research work of ultrasonic cutting spindle and acoustic system: the structure and function of the main axis of the requirements analysis,design for spindle system on NOMEX honeycomb composite ultrasonic cutting;finite element method based on the design of ultrasonic and ultrasonic cutting spindle matching cutting acoustic system,and focus on the part of the horn the acoustic system is analyzed and optimized by experiments;the resonance frequency,the acoustic system impedance and amplitude parameters of the test,and observe the cutting surface quality,verify the correctness and feasibility of the design of ultrasonic cutting spindle and its acoustic system.The specific research content and results are as follows:(1)the characteristics and applications of NOMEX honeycomb composites are introduced,and the domestic and foreign processing status and related equipment of NOMEX honeycomb composites are studied.(2)for Nomex honeycomb composite material processing of ultrasonic cutting spindle and anti vibration requirements in the rotating precision and static stiffness,designed the sleeve parts structure of ultrasonic cutting spindle;the ultrasonic cutting tool and spindle control of straight bladed disc cutters,the spindle servo motor parameter calculation and selection.The design of the transmission structure;design of acoustic system signal transmission device,ensure the transmission signal to realize ultrasonic acoustic system before and after the replacement and machining process.(3)of ultrasonic generator and transducer are introduced,and the design meets the ultrasonic transducer for cutting;based on ANSYS finite element analysis method and alternative method for ultrasonic cutting straight knife horn is designed and optimized,get straight knife horn magnification and tool output amplitude;no-load horn and horn with a knife the circular knife through the finite element analysis software and optimization,obtains the amplitude magnification of disc cutter horn and tool output amplitude.(4)analyze the experimental resonant frequency and impedance characteristics of the acoustic system,get related parameters of resonant frequency and impedance characteristics;acoustic amplitude test system,get the magnification tool output amplitude and horn,to verify the accuracy of finite element analysis;ultrasonic cutting spindle test cutting experiments,the cutting force measurement of ultrasonic cutting the surface quality and cutting through the observation of microscopic scanning,ultrasonic cutting experiment found good surface quality,the cutting force is small,to meet the use requirements. |
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