A disposable telescopic drilling tool used for fire prevention and grouting in coal mines

Abstract

The invention discloses a disposable telescopic drilling tool used for fire preventing and extinguishing grouting in an underground coal mine. A front leading drill bit comprises three wing panels, joints of the three wing panels are in hollowed-out design, three top cutting disks located at the topmost end of the front leading drill bit rotate by 15 degrees towards the same direction along the side boundaries of the three wing panels correspondingly, and the projection portions of the three top cutting disks on a plane perpendicular to the axis of a rod body are overlapped; a flat key is arranged on the surface of the front portion of an inner core in the length direction, and a key groove matched with the flat key is formed in the inner wall of a sleeve in the length direction; and the rear end of the key groove makes contact with a clamping component, and a plurality of grouting holes are formed in the sleeve and the inner core. According to the disposable telescopic drilling tool used for the fire preventing and extinguishing grouting in the underground coal mine, under the precondition that hole-drilling construction is not influenced, a grouting way is extended from dot grouting to line grouting, and thick liquid is grouted from the multiple distributed grouting holes to a drilling rod, so that the grouting quantity is increased, the hole blocking probability is lowered, and grouting efficiency is improved; and full cutting is achieved, thus, the hole forming speed is greatly increased, and the three top cutting disks share the destructive power of a rock body to a single top cutting disk, so that the situation that hole drilling is successfully conducted is guaranteed.

Description

technical field [0001] The invention relates to a drilling tool, in particular to a disposable retractable drilling tool used for fire prevention and grouting in coal mines, belonging to mining equipment. Background technique [0002] Spontaneous combustion of coal often occurs in goafs in underground coal mines, which seriously affects underground safety. In order to prevent spontaneous combustion of coal, materials such as drilling and grouting into the coal seam, injection of foam gel, and foam are usually used. At present, when the above-mentioned materials are poured by drilling, firstly, there is a problem of small pouring volume, and the grout can only flow out from the flower hole (flower tube) on the top of the drill bit or the drill pipe, and it is easy to be blocked, which affects the grouting efficiency; Secondly, when drilling holes in fire zones that are not easy to form holes, such as broken coal or soft coal seams, due to the low porosity rate or difficult t...

AI Technical Summary

Problems solved by technology

At present, when the above-mentioned materials are poured by drilling, firstly, there is a problem of small pouring volume, and the grout can only flow out from the flower hole (flower tube) on the top of the drill bit or the drill pipe, and it is easy to be blocked, which affects the grouting efficiency; Secondly, when drilling holes in fire zones that are not easy to form holes, such as broken coal or soft coal seams, due to the low porosity rate or difficult to form holes, the grouting is affected and the efficiency of fire prevention and extinguishing is reduced; the 3rd, the existing drill bit There are generally cutting blind spots or blind areas at the front end, that is, only part of the cutting can be realized, which directly reduces the cutting efficiency, and when encountering hard coal, the cutting part is prone to chipping, which affects the construction efficiency

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