Numerical investigation of performance of hydraulic percussion drifter

Abstract

Drilling machines using the top hammer drilling method incorporate a drilling mechanism whereby the torque and percussive force generated by the hydraulic drifter are transferred to the rock surface through a rod and drill bit. To date, mainstream studies of the hydraulic drifter addressed the behavior of the elastic waves produced by the impact and the drilling characteristics related to rock properties. Meanwhile, studies of design sensitivity analysis and percussion performance improvement for the development of a high-efficiency hydraulic drifter have been insufficient. In this study, to develop a high-efficiency hydraulic drifter, the validity of a model was verified by comparing the test results with a previously constructed analysis model. In addition, using the model, the supply pressure and inlet flow rate, stroke regulator opening, and striking piston’s acting area and mass were selected as the design parameters affecting the percussion performance; through the impact frequency and impact energy, the percussion performance was analyzed. As a result, design values that improve the percussion performance were derived.