| 摘要 |
<p>A method for automatically controlling an opener holding a drill rod by exerting an impact on or by rotating the opener and by moving back and forth the opener by means of a feed motor hydraulically driven so as to open an iron notch comprises a step of measuring the feed load by using a measured hydraulic pressure, a step of stopping the feed when the measured hydraulic pressure reaches a preset upper limit at which buckling occurs and continuing only the rotation, and a step of resuming the feed when the measured hydraulic pressure decreases below a preset lower limit. Buckling and idle impact of the drill rod of the opener are prevented. Therefore the opening work is quickly done, the precision of the depth of the iron notch is improved, and the opening work is automated and remotely controlled.</p> |
