A Piezoelectric-driven Ultrasonic Drill for Hard Rock in Sea-floor Exploration

Drilling is an effective method for conducting seabed mineral exploration. To overcome the problems of high power consumption, high drilling pressure, and difficult waterproof design in traditional electromagnetic and hydraulic-driven drilling rigs, an ultrasonic drilling device is proposed based on the principle of piezoelectric driving for deep-sea hard rock exploration. This underwater drilling device has low power consumption, long endurance, compact structure and simple design for waterproofing. In addition, it can pierce hard rocks with only a small drilling pressure, showing good application potential in the field of deep-sea hard rock drilling. Based on vibration theory analysis, the structural design of the driving unit of the drill (that is piezoelectric actuator) is carried out. The output dynamic parameters of the piezoelectric actuator are obtained using finite element simulation and measuring experiment. Considering the working environment of the drilling task, the ultrasonic drill prototype is developed, and a drilling experiment platform is established. Experiments on the drilling characteristics of the ultrasonic drill verifies the feasibility of structural design.