ADAPTER FOR DRIVING ROCK BOLT

PURPOSE: To insert this side end part of a rock bolt in an insert hole to eliminate large stress concentration at the time of driving the bolt by forming an insert hole for an adapter for driving a rock bolt like a funnel. CONSTITUTION: An insert hole 15A disposed inside a little less than the half on this side of the interior of an adapter 11A for driving a rock bolt is formed in such a manner as to be tapered, the hole diameter at an inlet 30 is larger than the outline of this side end part of a pipe type rock bolt 7, and the inner part diameter is smaller than the outline of this side end part. The inlet 30 is rounded. At the time of driving a pipe type rock bolt 7 in a bore hole by the thus formed rock bolt driving adapter 11A, a shank rod 14 gripped by a driving machine 13 is connected to a rope screw 12, and this side end part of the pipe type rock bolt 7 is inserted in the insert hole 15A to drive the bolt. The insert hole 15A is formed like a funnel in such a manner as to be increased in the diameter toward the inlet, whereby even if two shafts are a little inclined, at the time of driving, only the end of this side end surface of the bolt 7 is brought into contact with the hole wall of the insert hole 15A.