| 摘要 |
FIELD: mining.SUBSTANCE: according to the first version a drill bit comprises a bit blank, the end of which is divided by washing slots into sectors, reinforced by well and core-forming inserts, calibrating blades of which are arranged along the inner and outer radii of the bit, besides, well and core-forming blades of inserts in plan have a serrated shape with at least two ledges, axes of symmetry of which cross in the point arranged beyond the outer surface of the bit and displaced relative to the radial plane to the side opposite to the direction of bit rotation. According to the second version a drill bit comprises a bit blank, the end of which is divided by washing slots into sectors, reinforced by paired well and core-forming inserts, calibrating blades of which are arranged along the inner and outer radii of the bit, besides, well and core-forming blades of inserts in plan have a serrated shape, at the same time tops of serrated ledges in paired inserts are directed to opposite sides, besides, in inserts that lead along the bit rotation the tops of ledges are directed to the side opposite to the direction of bit rotation.EFFECT: increased efficiency of bit operation, improved cooling of inserts, creation of favourable conditions of operation for core and well forming inserts.2 cl, 5 dwg |
