Large-diameter combined type air reverse circulation down-the-hole hammer

Abstract

The invention provides a large-diameter combined type air reverse circulation down-the-hole hammer. The large-diameter combined type air reverse circulation down-the-hole hammer comprises an air distribution joint assembly, a planetary gear shunt, a center hammer, side hammers, a bell-shaped shield, a connecting cover and a protective cylinder, wherein the air distribution joint assembly transmitstorque through a floating spline; the function switching of rotary-percussion drilling and strong blowing for removing slag after lifting a drill is realized by changing the position of a floating upper shaft; high-pressure gas is evenly distributed to each side hammer and the center hammer through the planetary gear shunt; the side hammers are evenly arranged around the center hammer; the bottomlip surface of a drill bit of the center hammer is ahead of the bottom lip surfaces of the drill bits of the side hammers; the bottom lip surface of the drill bit of the center hammer and the bottomlip surfaces of the drill bits of the side hammers are combined to form a complete circular cross section; the drill bit of each side hammer is installed by adopting a T-shaped slot structure, and canfloat in an axial direction; and the central drill bit is arranged by adopting a clip key type spline shaft. The down-the-hole hammer comprises an integral type outer protective cylinder; and the upper air distribution section comprises the bell-shaped shield. The down-the-hole hammer has stable gas distribution, compact structure and high rock crushing efficiency, is convenient to maintain and can realize multiple drilling techniques.

Description

technical field [0001] The invention relates to a large-diameter combined down-the-hole hammer drilling tool for rock and soil drilling construction, in particular to a large-diameter combined air-reverse hammer drill tool suitable for deep foundation construction of buildings in medium-hard and hard rock formations. Cyclic down-the-hole hammer. Background technique [0002] With the gradual development of above-ground and underground buildings in my country's cities to super-high and super-deep, how to efficiently carry out large-diameter pile foundation construction has become a hot issue. The most commonly used machine tool for pile foundation construction is the reverse circulation pneumatic down-the-hole hammer. The reverse circulation pneumatic down-the-hole hammer has an efficient rock breaking mechanism and a wide range of stratum applicability. Large-diameter combined DTH hammers are commonly used in the construction of large-diameter pile foundations, such as the ...

AI Technical Summary

Problems solved by technology

[0005] 1. Limited by the shape and spatial arrangement of the middle impactor bit and the peripheral impactor bit, the broken rock surface formed by the down-the-hole hammer drilling tool is not a complete broken rock surface, and a diameter is formed between each two impactors. Large, unbroken rock columns resist drilling tool footage, which causes the tool to have to impact more times to fully break the rock and drill deeper, reducing penetration rate

[0006] 2. The compressed air is not evenly distributed when it is transported to the impactor through the pipeline. The impact energy generated by different impactors is uneven, and the depth of the rock hole produced during drilling is different, which is easy to cause hole inclination.

In addition, each impactor requires a separate set of pipelines to be connected to the air compressor, which increases the difficulty of installation and certain risks

[0007] 3. Because the structure of the drilling tool is not compact enough and the installation reliability is poor, the installation of the drilling tool is difficult and the maintenance cost is high

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