The application discloses a design method of a longitudinal-bending
ultrasonic vibration assisted
deep hole drilling device, which comprises the following steps: selecting a working frequency of the longitudinal-bending
ultrasonic vibration assisted
deep hole drilling device and materials of each part of the device; sequentially performing
transducer design to determine the length and
diameter of a
front cover plate, a middle cover plate and a rear cover plate and the position of a piezoelectric sheet; performing amplitude rod design to determine the length and
diameter of each section of the amplitude rod; constructing a geometric model according to the size of the
transducer and the amplitude rod, a bolt pre-tightening structure and a connecting structure of a tool and the device, the device and a
machine tool; outputting trajectory modeling; and performing structure optimization and frequency degeneration of the longitudinal-bending
ultrasonic vibration assisted
deep hole drilling device based on
finite element simulation. Thus, the general structure design of the double-excitation longitudinal-bending ultrasonic vibration assisted
deep hole drilling device is realized, the frequency degeneration of the
longitudinal vibration and the
bending vibration is achieved and the amplification coefficient reaches the maximum, so that the design problem of the double-excitation longitudinal-bending same-frequency vibration device is solved.