tungsten-carbide bit

A type of drill used in core drilling. The steel cylindrical bit body is named after the tungsten carbide cutting tools inlaid with tungsten carbide. The shape of carbide cutting tools and the number, arrangement and Angle of insert welding are called bottom edge, inside edge and outside edge to ensure the gap between water and powder discharge. The upper part of the bit body is connected with the core pipe by a screw, the side part of the bit body is provided with a water tank, and the bottom lip is also provided with a water mouth. The flume and nozzle are to ensure the flow of washing fluid, to eliminate rock powder and cool the bit. In order to increase the clearance when drilling clay and shale formations, ribs are welded on the inner and outer wall of hard alloy bit, which is called rib bit. Needle-like carbide self-grinding bits can be used in hard formations with high abrasives. General hard alloy bit drilling rock drillability of class ⅱ - ⅶ strata; Needle-like carbide bit can drill grade ⅵ ⅷ rock.

Carbide bits break rock by weight on bit and impact load generated by rotation. In rock drilling, the drill bit is subjected to high frequency impact load, and is subjected to torsion, bending, stretching, compression and other complex stresses. In the environment of high-speed rotary collision, the drill bit is subjected to wear and corrosion of rock, rock powder and mineral water and other working media.

Most of the cone bits used at home and abroad are tricone bits. This bit is characterized by a wide and uniform distribution of axial compression and impact loads, and the full utilization of effective space, and smooth drilling. The size and shape of the carbide teeth used in the cone bit must be suitable for the characteristics of the rock, requiring good wear resistance, high strength, and not easy to fracture and break. The main carbide teeth used in cone bit are: spherical teeth, cone teeth, wedge teeth, edge wedges and flat teeth for the back of the wheel and the tip of the claw.

Generally, roller cone bits used for drilling extremely hard rock strata mainly use spherical teeth, woB of 892-1339 mpa, rotating speed of 50-80 r/min; The cone bit used for drilling hard and medium-hard rock strata uses cone-ball teeth, with woB of 714~1071MPa and rotating speed of 60~100r/min. Roller cone bits, which drill soft and medium soft rock formations, use wedges or side wedges with woB of 535-803 mpa and rotation speed of 80-120 r/min.