METHOD AND DEVICE FOR IMPACT LOOSENING OF THREAD JOINTS

摘要

Method of impact loosening of thread joints at rock drilling, whereby vibrations from a drill string (1) are sensed at the same time as a rock drilling machine (2) exerts the drill string (1) to impacts without feeding the drill string (1) against a ground (3), that the sensed vibrations are supplied to an analysis tool (4), that the sensed vibrations are compared with known vibration patterns by the analysis tool and that a signal is sent to a control system (5) for controlling the rock driling machine (2) for stopping the impact device of the rock drilling machine when the analysis tool detects that the sensed vibrations correspond to the known vibration pattern which marks that the thread joints have been loosened by impact. Device for detecting impact loosening of thread joints at rock drilling comprising a rock drilling machine (2) movable along a feed beam (6) for exerting a drill string (1) to impacts, having a device (7) for sensing of vibrations from the drill string (1), an analysis tool (4) for comparing the sensed vibrations with known vibration patterns, that the analysis tool (4) is arranged to send a signal when the sensed vibrations correspond to the known vibration pattern which marks that the thread joints have been impact loosened and a control system (5) for controlling the rock drilling machine (2), whereby the control system (5) is arranged to turn off the impact device of the rock drilling machine (2) when the analysis tool sends the signal.