Improve the advantages of cemented carbide drill bits

Improving the structure of the cemented carbide drill bit can improve the quality of the inner hole.

1. Grind the drill bit to a geometric shape suitable for high-speed drilling. Because high-speed drilling requires the drill bit to have good chip breaking and chip removal performance.

2. It is required to sharpen the self-centering drill bit structure, so as to eliminate the need for center drilling for drilling and to ensure that the center of the inner hole does not drift.

3. The new type drill bit breaks the traditional concept and is designed into a triple spiral groove structure. It is proved by cutting test that the cemented carbide triple spiral groove structure drill has the following advantages:

(l) Cutting with three cutting edges can greatly increase the removal rate compared with ordinary high-speed steel drills.

(2) Three spiral grooves increase the chip removal space and greatly enhance the chip removal capacity.

(3) The appearance of the third cutting edge enables the drill to advance in a straight line, reducing the deflection of the inner hole.

(4) The cutting force on each cutting edge is reduced, and the third band is added, which can smooth the machined inner hole, thereby reducing the surface roughness of the inner hole.

(5) The three-spiral flute drill with good rigidity can prevent the drill from bending and deforming when processing the discontinuous surface, so that it can enter and exit from the discontinuous surface smoothly, without gnawing and scratching the inner surface of the hole.

(6) When a large amount of heat and chips are generated in the cutting zone during drilling, the use of two carbide drills with spiral grooves with cooling lubricant in the middle can reduce cutting heat and smooth chip removal. At the same time, due to the addition of two spiral groove oil holes, the drill bit has no chisel edge, which greatly reduces the large axial force generated by the drill bit processing, and also ensures that it stores more than the linear coolant hole. The large volume of coolant improves the cooling and lubricating effect of the drill bit. At present, this kind of cemented carbide drill can be used in a horizontal and vertical primary bed with sufficient rigidity to have a small Zomm and a small and deep hole with a hole depth/aperture ratio of 7 or more. The dimensional accuracy and surface roughness of the processed inner hole are better than those processed by the high-speed steel drill/reamer composite tool and the drill ream.