| 摘要 |
PURPOSE: To easily provide boring accuracy so as to correspond to boring at and within a specific normal angle and small step width by providing a tilting cylinder for inclining a guide, a guide cell slidably supported on the guide, an auto rod changer or the like. CONSTITUTION: At a boring process, a derricking cylinder 4 and a turning cylinder 8 are operated to move a guide cell 11 from a position A to another position B over a distance D of such length as keeping a normal angleθin parallel to a 45-degree slope face S and keeping an auto rod changer 18 roughly free from interfering with the face S. Thereafter, a slide cylinder 12 is operated to lower the guide cell 11 and the slope 13a of a bracket 13 is pressed and fixed to a small step at the slope face S. At the same time, a hood 15 is caused to slide and cover a boring area. Then, a drifter 17 is operated to rotate a rod 19 for boring in parallel to the slope face S. As a result, a boring work can be undertaken to an angle of 45 degrees. Also, a horizontal distance D1 can be obtained from the distance D for constructing a small step of specific width.
|
