A device and method for drilling deep longitudinal slits

Abstract

The invention belongs to the technical field of coal mine exploitation mine pressure prevention and control, and provides a drilling deep portion longitudinal joint cutting device. A drill bit built-in small explosion-proof motor is arranged in the head section of a hollow drill rod, a power supply device is electrically connected with the drill bit built-in small explosion-proof motor in order tosupply power to the drill bit built-in small explosion-proof motor, a mounting clamping plate is mounted at the position of the end face of the head portion of the hollow drill rod, a diamond saw blade is mounted in the mounting clamping plate through a transmission shaft, part of an outer blade of the diamond saw blade protrudes out of the mounting clamping plate, the diameter of the diamond sawblade is larger than that of the hollow drill rod, a motor transmission gear is mounted at the power end of the drill bit built-in small explosion-proof motor, and the motor transmission gear drivesa secondary transmission shaft and the diamond saw blade to rotate for cutting through a transmission gear set. An operation assembly for controlling the hollow drill rod is further arranged on the tail of the hollow drill rod, and power can be supplied to the drill bit built-in small explosion-proof motor through an external cable or a built-in battery. The invention further provides a drilling deep portion longitudinal joint cutting method.

Description

technical field [0001] The invention belongs to the technical field of prevention and control of mine pressure in coal mine mining, and in particular relates to a longitudinal slit device and method for the position of the deep roof of an underground borehole in a coal mine. Background technique [0002] The coal mining process is accompanied by the movement of the overlying rock, and the movement of the rock formation is often controlled by the hard roof above the coal seam. After the working face is advanced, if the hard roof cannot collapse in time, a large area of ​​cantilevers will be formed behind the working face or on both sides of the roadway. It brings great difficulties, often adopting various support methods cannot achieve a good control effect on the surrounding rock. In addition, for high-gas mines, the existence of the cantilever for a long time will cause gas accumulation in the upper corner. In coal and gas outburst mines, the large-area stress concentratio...

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Problems solved by technology

[0003] As a pressure relief technology for gob-side entry retaining, blasting roof cutting can play the role of cutting the cantilever of the roof. However, the construction procedure is relatively complicated, and the distance between blasting and drilling holes is generally about 600mm. The construction cost is high and the safety is poor; Tongmei Group The self-developed KLJ intelligent chain arm sawing machine for mining can realize the mechanical cutting of the direct roof, the cutting surface is smooth, and the roof cutting effect is good. However, the maximum depth can only reach 6.6m at present, and the cutting of the hard old roof above is temporary It is still not possible; conventional hydraulic fracturing, as an economical and effective treatment technology for hard and difficult roofs, has been popularized and applied at home and abroad. However, the expansion path of cracks cannot be effectively controlled. The initial caving work of cracks is large, and the pressure relief effect of roadway roof cutting is not obvious; in order to realize crack cracking and further realize effective control of crack expansion, directional hydraulic fracturing technology is usually used, that is, through hydraulic fracturing drilling wall Manufacture two artificial fractures on the surface to guide the cracking and expansion direction of hydraulic fracturing fractures, so that two directional hydraulic fracturing methods, horizontal grooving hydraulic fracturing and longitudinal grooving hydraulic fracturing, are often used, and vertical grooving hydraulic fracturing Compared with transverse groove hydraulic fracturing, the guiding direction of the fracture is more conducive to roof collapse

[0004] Compared with the small-aperture pneumatic double-edged longitudinal grooving drill for in-hole grooving, the small-aperture pneumatic double-edged longitudinal grooving drill for in-hole grooving uses the rear end rotor located outside the drill hole as the power source, through the built-in drill rod The transmission rod is long-distance transmission, the internal transmission gears between the drill rods need to be fully engaged, the connection accuracy is high, the operation process and transmission structure are complicated, the transmission efficiency is low, and the single-section drill rod is heavy and easy to rust and damage. Once a certain drill rod If there is a problem with the transmission, it is necessary to arrange each drill rod to find out the location of the transmission damage. It is not suitable for ultra-long-distance control in the deep part of the drill hole. Problems such as the tool not turning, the tool jamming, and the tool bending often occur. It is very difficult to form grooves and cannot be realized. Long-distance effective longitudinal slitting at the position of the hard roof in the deep part of underground coal mine drilling

[0005] Compared with a pre-fracture hydraulic fracturing roof cutting and pressure relief construction method and drilling equipment, a pre-fracture hydraulic fracturing roof cutting and pressure relief construction method and a drilling machine for groove drilling rigs are connected by radial transmission and small size The built-in micro motor in the rod drives the helical tip drill bit to rotate. Due to the limitation of the size of the radial transmission connecting rod, the size of the motor is small and the power is low, so it is impossible to achieve high-efficiency drilling on hard rock walls such as sandstone. The contact area between the helical point drill bit and the rock wall is large, which has a great destructive effect on the rock wall, and complex micro-cracks are easy to form near the groove, which greatly interferes with the expansion direction of hydraulic fracturing cracks in the later stage; when the tool cuts the rock wall It is easy to generate sparks, and the motor is prone to high temperature when it is working. The device does not have a corresponding water cooling system, and it is easy to ignite explosive gases such as underground gas, which poses a safety hazard; All are controlled by the gear transmission of the driving device. The transmission system and circuit system are complex, the operation process is complicated, and the conditions such as the hardness of the rock on the inner wall of the drilling hole are complex and changeable, and it is difficult to carry out real-time artificial control of the feed speed

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