The simulation and design of an ultrasonic vibrator using coolant through the spindle structure

The purpose of this study was the design of a vibrator that would be suitable for the ultrasonic tool holder using the coolant through spindle structure, as well as to investigate the effects of the shape, material and design of the vibrator on the performance of the tool holder assembly. The COMSOL Engineering simulation program was used for cross verification of resonance frequency and amplitude as well as to analyze the node position of the vibrator using the frequency analysis feature. Comparison of the measured and simulated values of the vibrator resonance frequency showed the error rate to be 2.97% and 2.76% for 2 cells and 4 cells of piezoelectric ceramic respectively. Next, during the experiment measuring by installing varied types of piezoelectric ceramics in the vibrator, it showed that a higher amplitude response could be achieved with PZT-8 piezoelectric ceramics material than was possible with PZT-4 material. The third experiment being conducted by locking the vibrator with varied bolt pretension forces indicated that an increase in bolt pretension force caused a sudden steep drop in initial equivalent impedance which gradually stabilized. During the final experiment, the performance response of the vibrator was also measured using tools of different size and the results showed that there was a difference of 600 Hz in resonance frequency between tools of 10 mm and 8 mm in diameter. Longer tools also resonated at lower frequency, but with higher amplitude. The maximum offset was expressed as 1000 Hz and 11.5 mu m.

Automated summary

The purpose of this study was to design a vibrator for an ultrasonic tool holder and investigate how its shape, material, and design affect the tool holder's performance. Simulation and experiments were conducted to analyze resonance frequency, amplitude, and other factors. The results showed that different materials, bolt pretension forces, and tool sizes have an impact on the vibrator's performance.