Reamer bit device of rotary drilling machine

The utility model discloses a reamer bit device of a rotary drilling machine. The reamer bit device comprises a bit, a reaming drill rod penetrates through the upper end of the bit, a positioning pin is inserted on the reaming drill rod on the left side of the bit, a limiting steel plate is arranged on the reaming drill rod on the right side of the bit, and alloy strips are arranged at the two ends of the reaming drill rod. The positioning pin and the limiting steel plate are arranged on the broaching drill rod and used for positioning and preventing the broaching drill bit from rotating in the direction perpendicular to the axis in the drilling process, disassembly and assembly are convenient, operation is easy, broaching efficiency is improved, and popularization is easy. 本实用新型公开了一种旋挖机扩孔钻头装置，包括钻头，在钻头的上端贯穿有扩孔钻杆，在钻头左侧的扩孔钻杆上插设有定位销，在钻头右侧的扩孔钻杆上设置有限位钢板，在扩孔钻杆的两端设置有合金条。本实用新型通过在扩孔钻杆上设置定位销和限位钢板，用于定位及防止钻孔过程中扩孔钻头垂直于轴线方向自转，拆装方便，操作简单，提高了扩孔效率，易于推广。