Concentric sliding block simultaneous casing drilling tool, center drilling bit and centralizer

Abstract

The invention discloses a concentric sliding block simultaneous casing drilling tool, a center drilling bit and centralizer. The concentric sliding block simultaneous casing drilling tool is formed by the centralizer, a ladder-shaped tapping center drilling bit and semicircle-shaped expanding drilling pieces, wherein the ladder-shaped tapping center drilling bit is connected and matched with a hole to which the centralizer is aligned for torque transmission, the ladder-shaped tapping center drilling bit is connected and located through a locating groove, a locating hole, a solid cylindrical pin and a hollow expansion pin, three semicircle-shaped expanding drilling pieces are in torque transmission through a T-shaped oblique groove and an R arc-shaped oblique groove, mutual included angles of the T-shaped oblique groove and the R arc-shaped oblique groove are 120 degrees by using an axis of the ladder-shaped tapping center drilling bit as the center, the semicircle-shaped expanding drilling pieces slide backwards to the end surface of the centralizer along the T-shaped oblique groove and the R arc-shaped oblique groove when being subjected to rock resistance and can be located, an expanding simultaneous casing can be formed, and the semicircle-shaped expanding drilling pieces slide downwards, can be narrowed and withdrawn due to the resistance of a pipe boot during upward drawing. According to the concentric sliding block simultaneous casing drilling tool disclosed by the invention, the front area of the tapping drilling bit is small, the force is concentrated, and the tapping drilling bit can crush harder or large rocks firstly at stages at crushing speed.

Description

technical field [0001] The invention relates to the construction of deep and shallow hole broken sections of related projects such as mine blasting, hydropower infrastructure construction, road slope foundation reinforcement, railway survey, and geological disaster prevention; Core, deep foundation pit support, high slope anchorage, tunnel collapse pipe shed support, pebble layer high-pressure rotary spraying, etc., involving a concentric follower and pipe concentric slider follower pipe drilling tool for a down-the-hole hammer . Background technique [0002] Most of the down-the-hole drilling tools currently on the market are eccentric drilling tools. According to years of practice, the existing eccentric drilling tools or other concentric drilling tools have obvious defects, such as In the process of use, the torque force is large, the drilling is not round, the drill is easy to stick, the pipe resistance is large, the eccentric swing is large, the force of the drilling t...

AI Technical Summary

Problems solved by technology

[0002] At present, most of the down-the-hole follow-up drilling tools sold in the market are eccentric follow-up drills. According to years of practice, the existing eccentric Tube drilling tools or other concentric drilling tools have obvious defects, such as large torque force, out-of-round drilling, easy drill sticking, high pipe resistance, large eccentric swing, uneven force on the drilling tool during use, Poor strength, must be reversed when pulling back, and prone to technical defects such as broken drill pipes and casings

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