超声换能器是超声振动辅助切削装置的核心部件，为研制适用于高速干切的大振幅超声振动辅助切削装置，需先对其进行设计研制。首先，基于考虑刀具的二级放大超声换能器设计方法，遵循“变幅杆-超声换能器”一体式设计理念，结合ANSYS有限元软件的模态分析和谐响应分析结果，设计并研制了二级放大超声换能器。根据所研制的二级放大超声换能器特性，对与其相匹配的超声波发生器、止转环、输电系统和刀柄壳结构进行了系统设计与研制。其次，针对所研制的二级放大超声换能器开展了阻抗分析和振幅测量的性能测试。最后，对所设计研制的大振幅超声振动辅助高速干切装置开展实验测试分析，探究了其对难加工材料30CrMnSiNi2A加工表面质量的改善程度。结果表明：所设计研制的二级放大超声换能器纵向振动仿真结果与理论设计一致。同时，二级放大超声换能器输出振幅稳定，在50 %输出功率下纵振振幅为15.4 μm，最大可达25.1 μm，且输出振幅与功率百分比成正相关，性能测试良好；所研制的大振幅超声振动辅助切削装置可大幅降低进给方向切削力和表面粗糙度，显著改善难加工材料加工表面质量，适用于难加工材料高速干切。

Ultrasonic transducer is the core component of ultrasonic vibration assisted cutting device, in order to develop a large-amplitude ultrasonic vibration assisted cutting device suitable for high-speed dry cutting, it is necessary to design and develop the ultrasonic transducer initially. First of all, based on the design method of the second-stage amplified ultrasonic transducer considering the tool, following the integrated design concept of amplifier-ultrasonic transducer, combined with the results of modal analysis and harmonious response analysis of ANSYS finite element software, the two-stage amplified ultrasonic transducer was designed and developed. According to the characteristics of the developed two-stage amplified ultrasonic transducer, the matching ultrasonic generator, anti-rotation ring, power transmission system and tool holder shell structure were designed and developed systematically. Secondly, the performance tests of impedance analysis and amplitude measurement were carried out for the developed two-stage amplified ultrasonic transducer. Finally, the experimental test and analysis of the designed and developed large-amplitude ultrasonic vibration assisted high-speed dry cutting device were carried out to explore the improvement of the surface quality of the difficult-to-machine material 30CrMnSiNi2A. The results show that the longitudinal ultrasonic vibration simulation results of the designed and developed two-stage amplified ultrasonic transducer are consistent with the theoretical design, and the longitudinal vibration amplitude output is stable. Besides, the longitudinal vibration amplitude is 15.4 μm at 50 % output power and can maximum reach 25.1 μm, and the output amplitude is positively correlated with the power percentage which means that the performance test is good. The developed large-amplitude ultrasonic vibration assisted cutting device can greatly reduce the cutting force and surface roughness in the feeding direction, significantly improve the surface quality of difficult-to-machine materials, and is suitable for high-speed dry cutting of difficult-to-machine materials.

TG663

国家重点研发计划(2020YFB2010500)。