Spiral drill bit with cutting teeth adjustable in dip angle

Abstract

The invention relates to a drill bit capable of adjusting the angle of drill bit cutting teeth. Comprising a connecting piece, a spiral blade, a core tube, cutting teeth and a drill tip assembly and is provided with a cutting tooth holder, the cutting tooth holder is fixed to the outer surface of the lower end of the core tube, the tail end of the spiral blade and the cutting tooth holder are fixed into a whole, a concave notch is formed in the cutting tooth holder, and a shaft hole penetrating through the concave notch is formed in the cutting tooth holder in the radial direction relative to the drill bit. A convex part is arranged at the upper end of the cutting tooth, a shaft hole is formed in the convex part, the convex part of the cutting tooth is in concave-convex fit with the concave notch of the cutting tooth holder, the rotating shaft sequentially penetrates through the shaft hole in the cutting tooth holder and the shaft hole in the convex part of the cutting tooth, the cutting tooth and the cutting tooth holder are connected together, and the rotating shaft and the cutting tooth are fixed or rotate relatively; a driving device is arranged and connected with the rotating shaft or the cutting teeth to drive the cutting teeth to rotate. According to the invention, the drilling and hole-forming efficiency is high, and loose soil does not fall off when the drilling tool is lifted during hole guiding.

Description

technical field [0001] The invention relates to a drill bit for construction, in particular to a spiral drill bit with adjustable inclination angle of cutting teeth. Background technique [0002] In the construction of building pile foundations, there are many applications of auger drilling, such as auger introduction holes for prefabricated piles, auger drilling for cast-in-place piles, etc. When drilling holes, for complex geological formations, the comprehensive drilling efficiency At the same time, during the drilling process, the soil on the screw blade at the lower part of the drill bit will fall to the bottom of the hole, forming a virtual soil at the bottom of the pile hole, which affects the bearing capacity of the pile. The reason is that the inclination angle of the cutting teeth of the auger bit used is fixed. Due to the different optimal crushing and cutting angles of different rock and soil layers, the optimal crushing and cutting angle of soft rock and soil i...

AI Technical Summary

Problems solved by technology

Due to the different cutting angles for different rock and soil layers, the best cutting angle for soft rock and soil is smaller, generally 45°, and the best cutting angle for hard rock is larger, generally 65°. If there is a large difference between the hardness and softness of the rock and soil layer on the wall of the pile hole, if the drill bit with the same cutting angle is used for construction, there will be disadvantages such as low drilling efficiency and large wear of the cutting teeth; The soil on the blade is in a semi-loose state, and it is easy to fall off. The fixed-angle cutting teeth cannot control the falling of the soil, resulting in too much empty soil at the bottom of the hole.

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