A drill bit, which directly impact into the rock, is operated by percussive force and torque. In order to increase the drilling efficiency, the buttons on drill bit head should be designed under the optimum arrangements. Thus, the drilling efficiency ...
A drill bit, which directly impact into the rock, is operated by percussive force and torque. In order to increase the drilling efficiency, the buttons on drill bit head should be designed under the optimum arrangements. Thus, the drilling efficiency should be investigated. In this study, percussion tests were carried out to assess the fragmentation performance of a drill bit. To investigate the drilling efficiency with testing conditions (i.e., blow speed and spacing), single and multiple piston-drop tests were performed on the granitic rock in Korea. After the tests, the drilled volumes of rock were measured by laser scanner. The drilling efficiency was eventually evaluated by calculating the percussive energy and the drilled volume.