Underground coal mine hydraulic fracturing hole drilling and sealing device and using method thereof

Abstract

The invention relates to the technical field of coal mine gas extraction devices, and particularly discloses a coal mine underground hydraulic fracturing hole drilling and sealing device and a using method thereof. The connector comprises a fixed communication mechanism, a hole sealing mechanism and a sealing mechanism. By arranging the air bag, the baffle ring and the rubber ring, when the connecting pipe moves towards the interior of the connector, the connecting pipe extrudes the rubber ring to move and compresses the rigid spring, so that the rigid spring extrudes the rubber ring to make close contact with the connecting pipe, and preliminary sealing is conducted; meanwhile, a rubber ring promotes an extrusion plate to compress hydraulic oil in a hydraulic oil cavity through a connecting rod, the hydraulic oil extrudes air bags at the two ends of the connector to expand, and a gap between a connecting pipe and the connector is sealed again; and the cavity ring drives the baffle ring to be in closed contact with the connector for final sealing. And the coal seam is fractured by injecting media such as water, so that subsequent gas extraction work can be carried out.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine gas extraction devices, and in particular to an underground coal mine hydraulic fracturing drilling sealing device and a use method thereof. Background Art

[0002] Hydraulic fracturing technology is widely used in gas extraction of low-permeability coal bodies in coal mines. It can effectively expand the pressure relief range of coal seams, increase the permeability of coal seams, and increase the amount of gas extraction from boreholes. At the same time, the gas outflow of wet coal seams after fracturing will be reduced during mining, and the amount of coal dust generated will also be reduced. Therefore, hydraulic fracturing technology provides an effective way to treat high-gas and low-permeability coal seams.

[0003] Unlike surface hydraulic fracturing of oil and gas resources, which relies on the deadweight of slurry in hundreds or even thousands of meters of boreholes to achieve borehole sealing, the practice of hydraulic fracturing in underground coal mines is affected by the poor flatness of the borehole wall, the short length of the borehole sealing, and the defects of the sealer itself. In the existing technology, when the sealer injects high-pressure water and other media to fracture the coal seam, it is easy for water and other media to leak from between the sealers, resulting in water leakage in the borehole and the scrapping of the fracturing hole, which directly affects the pressure relief and permeability enhancement effect of the coal seam and the subsequent gas extraction work, and seriously restricts the practice and application of hydraulic fracturing technology in underground coal mines. Summary of the invention

[0004] The purpose of the present invention is to provide a coal mine underground hydraulic fracturing drilling sealing device and a use method thereof to solve the problems raised in the above-mentioned background technology.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A coal mine underground hydraulic fracturing drilling sealing device, including a connector, the connector includes a fixed communication mechanism, a sealing mechanism and a sealing mechanism.

[0006] Among them, the sealing mechanism includes a hydraulic oil chamber, an air bag and a retaining ring. A hydraulic oil chamber is opened inside the connector, and extrusion plates are movably sleeved at both ends of the hydraulic oil chamber. A connecting rod is fixed to the side of the extrusion plate. One end of the connecting rod passes through the connector and is fixed with a rubber ring. A sleeve movably sleeved with the connector is fixed inside the rubber ring. A rigid spring located between the side of the rubber ring and the inner wall of the connector is movably sleeved on the outer surface of the connecting rod. Air bags are installed at both ends of the connector, and the retaining ring is installed on the fixed connecting mechanism.

[0007] Preferably, the sealing mechanism comprises a connecting tube connected to the connector, the number of the connecting tubes is 2, and the two connecting tubes are fixedly connected to the first sealing device and the second sealing device respectively.

[0008] Preferably, the fixed communication mechanism includes a driving component, a telescopic component and a fixing component.

[0009] Wherein, the fixing assembly includes a latch assembly, a rebound assembly and a limit assembly.

[0010] Among them, the pin assembly includes a cavity ring and a round head hole, the cavity ring is sleeved on the connecting tube, the connecting tube is provided with a round head hole, the interior of the cavity ring is movably sleeved with symmetrically distributed round head rods, the outer surface of the round head rods is movably sleeved with the inner wall of the round head hole, and the side of the cavity ring is fixedly connected to the retaining ring.

[0011] Preferably, the rebound assembly comprises a side plate, the side plate is fixed on the round head rod, a flexible spring is fixed on the side plate, and the end of the flexible spring is fixed to the inner wall of the cavity ring.

[0012] Preferably, the limiting assembly includes an insertion rod, a through hole, a fixing hole and a socket, the connector is fixed with symmetrically distributed insertion rods, the cavity ring is provided with a through hole, the round head rod is provided with a fixing hole, the connecting tube is provided with a socket, and the insertion rod, through hole, fixing hole and socket correspond to each other.

[0013] Preferably, the telescopic assembly comprises a square cavity, the screw hole rod is provided with a square cavity, a square block is movably sleeved inside the square cavity, a round rod is fixed to the side of the square block, and the end of the round rod passes through the screw hole rod and is fixed to the cavity ring.

[0014] Preferably, a sealing and blocking protection mechanism is also included.

[0015] Among them, the sealing and blocking protection mechanism includes a sealing component and a blocking and protection component.

[0016] Among them, the sealing component includes an injection tube, an expansion hose, side grooves and an injection hole. The injection tube and the expansion hose are fixed on the first hole sealer and the second hole sealer. The first hole sealer and the second hole sealer are both provided with annular equidistant side grooves and injection holes inside, and the side grooves are connected with the expansion hose through the injection hole.

[0017] Preferably, the blocking and protection assembly includes a block, a block is sleeved inside the side groove, a limiting hole is provided inside the block, a side block is movably sleeved inside the limiting hole, a sloped block is fixed to the side of the block, a fixing rod is fixed to the side of the side block, one end of the fixing rod passes through the sloped block and is fixed to the inner wall of the side groove, and a movable ring is fixed to the side of the block.

[0018] Preferably, a sleeve block movably connected to the expansion hose is fixed on the side of the movable ring, a rubber block is fixed on the side of the sleeve block, a return spring is fixed on the side block, a fixing ring is fixed on the end of the return spring, and there are two fixing rings, which are respectively fixed on the first hole sealer and the second hole sealer.

[0019] Preferably, a method for using a hydraulic fracturing drilling sealing device in an underground coal mine comprises the following steps:

[0020] S1. First, press the cavity ring and insert the connecting tube on the first hole sealer into the connector, so that the connecting tube pushes the round head rod to move and the side plate compresses the flexible spring. When the round head rod corresponds to the round head hole, the flexible spring squeezes the round head rod through the side plate, and then the round head rod moves into the round head hole.

[0021] S2, then push the cavity ring, so that the round rod drives the square block to move along the inner wall of the square cavity, until the insertion rod passes through the through hole and is inserted into the interior of the fixing hole, so that the insertion rod fixes the round head rod through the fixing hole, and then the connecting pipe on the second hole sealer is inserted into the interior of the connector in the same way;

[0022] S3. When the connecting tubes on the first hole sealer and the second hole sealer are both inserted into the connector, the dual-axis motor is started, the threaded rod drives the two cavity rings to move through the screw hole rod, and the cavity ring drives the connecting tube to move into the connector through the round head rod and squeezes the rubber ring until the cavity ring drives the retaining ring to close the connector and the dual-axis motor is stopped. At this time, the insertion rod is inserted into the inside of the jack, achieving the purpose of fixing and connecting the first hole sealer and the second hole sealer;

[0023] S4. Finally, the fixed first and second hole sealers are sent into the borehole of the coal seam through the drilling device, and water and other media are injected into the first and second hole sealers through the high-pressure water injection pump, so that the first and second hole sealers expand and seal the borehole, and the coal seam is fractured after continuing to inject water and other media to increase the pressure in the borehole, and then subsequent gas extraction work can be carried out.

[0024] Beneficial effects of the present invention:

[0025] 1. The present invention arranges an air bag, a retaining ring and a rubber ring. When the connecting pipe moves toward the inside of the connector, the connecting pipe squeezes the rubber ring to move and compresses the rigid spring, so that the rigid spring squeezes the rubber ring and closely contacts the connecting pipe to perform preliminary sealing. At the same time, the rubber ring prompts the extrusion plate to compress the hydraulic oil in the hydraulic oil chamber through the connecting rod, and the hydraulic oil squeezes the air bags at both ends of the connector to expand, prompting the gap between the connecting pipe and the connector to be sealed again. The cavity ring drives the retaining ring to make closed contact with the connector for final sealing, thereby achieving the purpose of sealing the drilling and sealing device and ensuring subsequent gas extraction work.

[0026] 2. The present invention sets a threaded rod, a screw hole rod and a round head rod, and by pressing the cavity ring, the connecting tube on the first hole sealer or the second hole sealer is inserted into the interior of the connector. When the round head rod corresponds to the round head hole, the flexible spring squeezes the round head rod through the side plate, and then the round head rod moves into the interior of the round head hole; then the cavity ring is pushed until the insertion rod passes through the perforation and is inserted into the interior of the fixing hole, so that the insertion rod fixes the round head rod through the fixing hole, and the dual-axis motor is started. The threaded rod drives the two cavity rings to move through the screw hole rod, and the cavity ring drives the two connecting tubes to move toward the interior of the connector through the round head rod until the first hole sealer and the second hole sealer are fixedly connected and stop, thereby achieving the purpose of facilitating the fixing, disassembly and connection of the first hole sealer and the second hole sealer.

[0027] 3. The present invention provides a slope block, a return spring and a sleeve block, and injects water and other media into the first hole sealer and the second hole sealer through the injection pipe, so that the water and other media in the first hole sealer and the second hole sealer squeeze the stopper through the slope block until the slope block releases the blocking of the injection hole; at the same time, the side block drives the sleeve block to move to release the blocking of the expansion hose and stretch the return spring, so that water and other media enter the interior of the expansion hose through the side groove and the injection pipe in turn, causing the expansion hose to expand, and continuing to inject water and other media to increase the pressure in the borehole to fracture the coal seam; when the expansion hose is not in use, the return spring will pull the sleeve block through the moving ring to block the expansion hose, and the sleeve block drives the rubber block to squeeze and contact with the connecting pipe, thereby achieving the purpose of blocking and protecting the expansion hose. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 It is a structural schematic diagram of the connector of the present invention;

[0031] Figure 3 is a front cross-sectional structural schematic diagram of the connector of the present invention;

[0032] Figure 4 is a schematic diagram of the side cross-sectional structure of the cavity ring of the present invention;

[0033] Figure 5 It is a front cross-sectional structural schematic diagram of the screw hole rod of the present invention;

[0034] Figure 6 It is a structural schematic diagram of the connecting pipe of the present invention;

[0035] Figure 7 is a front cross-sectional structural schematic diagram of a second hole sealer of the present invention;

[0036] Figure 8 The present invention Figure 2 A schematic diagram of the partially enlarged structure at center A;

[0037] Fig. 9 The present invention Figure 3 Schematic diagram of the local enlarged structure at point B in the middle.

[0038] In the figure: 1, connector; 2, first hole sealer; 3, second hole sealer; 4, connecting pipe; 5, hydraulic oil chamber; 6, air bag; 7, extrusion plate; 8, connecting rod; 9, rigid spring; 10, sleeve; 11, double-axis motor; 12, threaded rod; 13, screw hole rod; 14, square cavity; 15, square; 16, round rod; 17, cavity ring; 18, round head rod; 19, side plate; 20, flexible spring; 21 , round head hole; 22, plug rod; 23, plug hole; 24, fixing hole; 25, through hole; 26, retaining ring; 27, rubber ring; 28, injection tube; 29, side groove; 30, injection hole; 31, expansion hose; 32, ramp block; 33, retaining block; 34, moving ring; 35, reset spring; 36, sleeve block; 37, fixing ring; 38, rubber block; 39, fixing rod; 40, side block; 41, limit hole. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0040] A hydraulic fracturing drilling sealing device for coal mines is a type of gas mining equipment in the resource utilization industry. It is used to mine and reuse coal mine gas, reuse coal mine resources, and improve the utilization rate of coal mine gas and other energy sources. Figures 1 to 9 As shown, it includes a connector 1, and the connector 1 includes a fixed communication mechanism, a sealing mechanism and a sealing mechanism;

[0041] Among them, the sealing mechanism includes a hydraulic oil chamber 5, an air bag 6 and a retaining ring 26. A hydraulic oil chamber 5 is opened inside the connector 1, and extrusion plates 7 are movably sleeved at both ends of the hydraulic oil chamber 5. A connecting rod 8 is fixed to the side of the extrusion plate 7. One end of the connecting rod 8 passes through the connector 1 and is fixed with a rubber ring 27. A sleeve 10 movably sleeved with the connector 1 is fixed inside the rubber ring 27. A rigid spring 9 located between the side of the rubber ring 27 and the inner wall of the connector 1 is movably sleeved on the outer surface of the connecting rod 8. Air bags 6 are installed at both ends of the connector 1, and the retaining ring 26 is installed on the fixed connecting mechanism.

[0042] Through the design of the hydraulic oil chamber 5, the airbag 6 and the retaining ring 26, when the fixed connection mechanism drives the sealing mechanism to be inserted into the connector 1 for fixed connection, the sealing mechanism squeezes the rubber ring 27 and the sleeve 10 to move along the inner wall of the connector 1 and compress the rigid spring 9, so that the rigid spring 9 squeezes the rubber ring 27 and closely contacts the sealing mechanism to perform preliminary sealing; at the same time, the rubber ring 27 causes the extrusion plate 7 to compress the hydraulic oil inside the hydraulic oil chamber 5 through the connecting rod 8, and the hydraulic oil squeezes the airbags 6 at both ends of the connector 1 to expand, and the expanded airbags 6 re-seal the gap between the sealing mechanism and the connector 1; the fixed connection mechanism drives the retaining ring 26 to close the contact with the connector 1 for the final sealing. Such a design ensures that when water and other media are injected into the connector 1, there will be no leakage, avoiding affecting the normal use of the sealing mechanism, and achieving the purpose of the sealing drilling and sealing device.

[0043] like Figure 1 As shown, the sealing mechanism includes a connecting tube 4 connected to the connector 1 , and the number of the connecting tubes 4 is two. The two connecting tubes 4 are fixedly connected to the first sealing device 2 and the second sealing device 3 respectively.

[0044] Through the design of the connecting tube 4 and the first hole sealer 2 and the second hole sealer 3 , the first hole sealer 2 and the second hole sealer 3 are fixedly connected to the connector 1 through the connecting tube 4 and used together.

[0045] like Figure 3 As shown, the fixed communication mechanism includes a driving component, a telescopic component and a fixed component;

[0046] Wherein, the fixing assembly includes a latch assembly, a rebound assembly and a limit assembly;

[0047] Among them, the latch assembly includes a cavity ring 17 and a round head hole 21, the cavity ring 17 is sleeved on the connecting tube 4, the connecting tube 4 is provided with a round head hole 21, the interior of the cavity ring 17 is movably sleeved with symmetrically distributed round head rods 18, the outer surface of the round head rods 18 is movably sleeved with the inner wall of the round head hole 21, and the side of the cavity ring 17 is fixedly connected to the retaining ring 26.

[0048] Through the design of the round head rod 18 and the round head hole 21, when the operator pulls the connecting tube 4 toward the outside of the connector 1, the round head hole 21 will squeeze the round head rod 18 out of the inside of the connecting tube 4 and make the round head rod 18 squeeze the rebound component, so that the connecting tube 4 can be removed from the connector 1, thereby achieving the purpose of removing the connecting tube 4.

[0049] like Figure 4 As shown, the rebound assembly includes a side plate 19 , the side plate 19 is fixed on the round head rod 18 , a flexible spring 20 is fixed on the side plate 19 , and the end of the flexible spring 20 is fixed to the inner wall of the cavity ring 17 .

[0050] Through the design of the side plate 19 and the flexible spring 20 , the flexible spring 20 pulls the round head rod 18 through the side plate 19 to fit more closely with the round head hole 21 .

[0051] like Figure 2 , Figure 4 , Figure 6 and Figure 7 As shown, the limiting assembly includes an insertion rod 22, a through hole 25, a fixing hole 24 and a plug hole 23. The connector 1 is fixed with symmetrically distributed insertion rods 22, the cavity ring 17 is provided with a through hole 25, the round head rod 18 is provided with a fixing hole 24, and the connecting tube 4 is provided with a plug hole 23. The insertion rod 22, the through hole 25, the fixing hole 24 and the plug hole 23 correspond to each other.

[0052] Through the design of the insertion rod 22 and the fixing hole 24, when the insertion rod 22 is inserted into the inner wall of the fixing hole 24, the insertion rod 22 fixes the round head rod 18 through the fixing hole 24, so that the round head rod 18 cannot escape from the inside of the round head hole 21, thereby achieving the purpose of fixing the round head rod 18.

[0053] like Figure 3 As shown, the driving assembly includes a dual-axis motor 11, which is fixed on the connector 1. Both ends of the dual-axis motor 11 are respectively connected to threaded rods 12, and the outer surface of the threaded rod 12 is threadedly sleeved with a screw hole rod 13 connected to the telescopic assembly.

[0054] Through the operation of the dual-axis motor 11, the threaded rod 12 drives the telescopic components to move toward each other through the screw hole rod 13, thereby achieving the purpose of moving the telescopic components toward each other.

[0055] like Figure 4 As shown, the telescopic assembly includes a square cavity 14, a square cavity 14 is opened inside the screw hole rod 13, a square block 15 is movably sleeved inside the square cavity 14, a round rod 16 is fixed to the side of the square block 15, and the end of the round rod 16 passes through the screw hole rod 13 and is fixed to the cavity ring 17.

[0056] Through the design of the square cavity 14 and the block 15 , the cavity ring 17 can move left and right, so that the cavity ring 17 can move to the position of the through hole 25 and the fixing hole 24 , and the insertion rod 22 passes through the through hole 25 and is inserted into the fixing hole 24 to fix the round head rod 18 .

[0057] like Figure 7 As shown, it also includes a sealing hole blocking protection mechanism;

[0058] Wherein, the hole sealing and blocking protection mechanism comprises a hole sealing component and a blocking and protection component;

[0059] Among them, the sealing component includes an injection tube 28, an expansion hose 31, a side groove 29 and an injection hole 30. The injection tube 28 and the expansion hose 31 are fixed on the first hole sealer 2 and the second hole sealer 3. The first hole sealer 2 and the second hole sealer 3 are both provided with annular equidistant side grooves 29 and injection holes 30 inside, and the side grooves 29 are connected with the expansion hose 31 through the injection hole 30.

[0060] Water or other medium is injected into the first hole sealer 2 and the second hole sealer 3 through the injection pipe 28 , and the water or other medium enters the expansion hose 31 through the side groove 29 and the injection pipe 28 in turn, causing the expansion hose 31 to expand.

[0061] like Figure 7 As shown, the blocking and protection assembly includes a block 33, the block 33 is sleeved inside the side groove 29, a limiting hole 41 is provided inside the block 33, a side block 40 is movably sleeved inside the limiting hole 41, a ramp block 32 is fixed to the side of the block 33, a fixing rod 39 is fixed to the side of the side block 40, one end of the fixing rod 39 passes through the ramp block 32 and is fixed to the inner wall of the side groove 29, a moving ring 34 is fixed to the side of the block 33, a sleeve block 36 movably connected to the expansion hose 31 is fixed to the side of the moving ring 34, a rubber block 38 is fixed to the side of the sleeve block 36, a reset spring 35 is fixed to the side block 40, a fixing ring 37 is fixed to the end of the reset spring 35, and the number of the fixing rings 37 is 2, and the two fixing rings 37 are respectively fixed to the first hole sealer 2 and the second hole sealer 3.

[0062] When the expansion hose 31 is not in use, the return spring 35 will pull the sleeve block 36 through the movable ring 34 to block the expansion hose 31, and the sleeve block 36 drives the rubber block 38 to be in compression contact with the connecting pipe 4, thereby achieving the purpose of blocking and protecting the expansion hose 31.

[0063] A method for using a hydraulic fracturing drilling sealing device in a coal mine, comprising the following steps:

[0064] S1. First, press the cavity ring 17 and insert the connecting tube 4 on the first hole sealer 2 into the connector 1, so that the connecting tube 4 pushes the round head rod 18 to move, and the side plate 19 compresses the flexible spring 20. When the round head rod 18 corresponds to the round head hole 21, the flexible spring 20 squeezes the round head rod 18 through the side plate 19 and moves into the inside of the round head hole 21;

[0065] S2, then push the cavity ring 17, so that the round rod 16 drives the block 15 to move along the inner wall of the square cavity 14, until the insertion rod 22 passes through the through hole 25 and is inserted into the fixing hole 24, so that the insertion rod 22 fixes the round head rod 18 through the fixing hole 24, and then the connecting pipe 4 on the second hole sealer 3 is inserted into the connector 1 in the same way;

[0066] S3, when the connecting tubes 4 on the first hole sealer 2 and the second hole sealer 3 are both inserted into the connector 1, the double-axis motor 11 is started, the threaded rod 12 drives the two cavity rings 17 to move through the screw hole rod 13, and the cavity ring 17 drives the connecting tube 4 to move into the connector 1 through the round head rod 18 and squeezes the rubber ring 27 until the cavity ring 17 drives the retaining ring 26 to make a closed contact with the connector 1, and the double-axis motor 11 is stopped. At this time, the insertion rod 22 is inserted into the inside of the insertion hole 23, achieving the purpose of fixing and connecting the first hole sealer 2 and the second hole sealer 3;

[0067] S4. Finally, the fixed first sealer 2 and the second sealer 3 are sent into the borehole of the coal seam through the drilling device, and water and other media are injected into the first sealer 2 and the second sealer 3 through the high-pressure water injection pump, so that the first sealer 2 and the second sealer 3 expand and seal the borehole, and the coal seam is fractured after continuing to inject water and other media to increase the pressure in the borehole, and then subsequent gas extraction work can be carried out.

[0068] Working principle:

[0069] First, press the cavity ring 17 and insert the connecting tube 4 on the first hole sealer 2 into the connector 1, so that the connecting tube 4 pushes the round head rod 18 to move, and the side plate 19 compresses the flexible spring 20. When the round head rod 18 corresponds to the round head hole 21, the flexible spring 20 squeezes the round head rod 18 through the side plate 19 and moves into the round head hole 21; then push the cavity ring 17, so that the round rod 16 drives the square 15 to move along the inner wall of the square cavity 14, until the insertion rod 22 passes through the through hole 25 and is inserted into the fixing hole 24, so that the insertion rod 22 passes through the fixing hole 24 is used to fix the round-headed rod 18, and then the connecting tube 4 on the second hole sealer 3 is inserted into the interior of the connector 1 in the same way; when the connecting tubes 4 on the first hole sealer 2 and the second hole sealer 3 are both inserted into the interior of the connector 1, the dual-axis motor 11 is started, and the threaded rod 12 drives the two cavity rings 17 to move through the screw hole rod 13, and the cavity ring 17 drives the two connecting tubes 4 to move toward the interior of the connector 1 through the round-headed rod 18 until the first hole sealer 2 and the second hole sealer 3 are fixedly connected and stop, thereby achieving the purpose of fixing and connecting the first hole sealer 2 and the second hole sealer 3.

[0070] When the connecting tube 4 moves toward the inside of the connector 1, the connecting tube 4 squeezes the rubber ring 27 and the sleeve 10 to move along the inner wall of the connector 1 and compress the rigid spring 9, so that the rigid spring 9 squeezes the rubber ring 27 and closely contacts the connecting tube 4 to perform preliminary sealing; at the same time, the rubber ring 27 causes the extrusion plate 7 to compress the hydraulic oil in the hydraulic oil chamber 5 through the connecting rod 8, and the hydraulic oil squeezes the airbags 6 at both ends of the connector 1 to expand, and the expanded airbags 6 seal the gap between the connecting tube 4 and the connector 1 again; the cavity ring 17 drives the retaining ring 26 to close the contact with the connector 1 for the final sealing. This design ensures that when water and other media are injected into the connector 1, there will be no leakage, avoiding affecting the normal use of the sealing mechanism, and achieving the purpose of sealing the drilling and sealing device. , ensuring the subsequent gas extraction work.

[0071] When it is necessary to disassemble the first hole sealer 2 and the second hole sealer 3, first start the dual-axis motor 11 to disengage the fixing hole 24 on the round head rod 18 from the insertion rod 22; then the operator pulls the connecting tube 4 to the outside of the connector 1, at which time the round head hole 21 squeezes the round head rod 18 out of the inside of the connecting tube 4, and causes the side plate 19 to squeeze the flexible spring 20; finally, the connecting tube 4 can be disassembled from the connector 1, thereby achieving the purpose of facilitating the disassembly of the first hole sealer 2 and the second hole sealer 3.

[0072] The fixed first and second hole sealers 2 and 3 are sent into the borehole of the coal seam through the drilling device, and then water and other media are injected into the first and second hole sealers 2 and 3 through the injection pipe 28 by a high-pressure water injection pump, so that the water and other media in the first and second hole sealers 2 and 3 are squeezed by the inclined block 32 to squeeze the stopper 33 until the inclined block 32 releases the obstruction of the injection hole 30, and at the same time, the side block 40 drives the sleeve block 36 to move to release the obstruction of the expansion hose 31 and stretch the reset spring 35, and the fixing rod 39 limits the stopper 33 through the side block 40 and the limiting hole 41, so that water and other media enter the inside of the expansion hose 31 through the side groove 29 and the injection pipe 28 in turn, and the expansion hose 31 expands. After continuing to inject water and other media to increase the pressure in the borehole, the coal seam is fractured, and then subsequent gas extraction work can be carried out.

[0073] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A coal mine underground hydraulic fracturing drilling sealing device, comprising a connector (1), characterized in that: The connector (1) comprises a fixed communication mechanism, a hole sealing mechanism and a sealing mechanism; The sealing mechanism comprises a hydraulic oil chamber (5), an air bag (6) and a retaining ring (26); the connector (1) is provided with a hydraulic oil chamber (5); the two ends of the hydraulic oil chamber (5) are movably sleeved with an extrusion plate (7); a connecting rod (8) is fixed to the side of the extrusion plate (7); one end of the connecting rod (8) passes through the connector (1) and is fixed with a rubber ring (27); a sleeve (10) movably sleeved with the connector (1) is fixed inside the rubber ring (27); a rigid spring (9) located between the side of the rubber ring (27) and the inner wall of the connector (1) is movably sleeved on the outer surface of the connecting rod (8); air bags (6) are installed at both ends of the connector (1); and the retaining ring (26) is installed on the fixed connecting mechanism.

2. The underground hydraulic fracturing drilling and sealing device of coal mine according to claim 1, characterized in that: The hole sealing mechanism comprises a connecting pipe (4) connected to the connector (1), the number of the connecting pipes (4) being two, and the two connecting pipes (4) being fixedly connected to the first hole sealer (2) and the second hole sealer (3) respectively.

3. The underground hydraulic fracturing drilling and sealing device of coal mine according to claim 1, characterized in that: The fixed communication mechanism includes a driving component, a telescopic component and a fixing component; Wherein, the fixing assembly includes a latch assembly, a rebound assembly and a limit assembly; The latch assembly comprises a cavity ring (17) and a round head hole (21); the cavity ring (17) is sleeved on the connecting tube (4); the round head hole (21) is formed on the connecting tube (4); symmetrically distributed round head rods (18) are movably sleeved inside the cavity ring (17); the outer surface of the round head rod (18) is movably sleeved on the inner wall of the round head hole (21); and the side surface of the cavity ring (17) is fixedly connected to a retaining ring (26).

4. The underground hydraulic fracturing drilling and sealing device of coal mine according to claim 3, characterized in that: The rebound assembly comprises a side plate (19), the side plate (19) is fixed on the round head rod (18), a flexible spring (20) is fixed on the side plate (19), and the end of the flexible spring (20) is fixed to the inner wall of the cavity ring (17).

5. The underground coal mine hydraulic fracturing drilling sealing device according to claim 3, characterized in that: The limiting assembly comprises an insert rod (22), a through hole (25), a fixing hole (24) and an insert hole (23); the connector (1) is fixed with symmetrically distributed insert rods (22); the cavity ring (17) is provided with a through hole (25); the round head rod (18) is provided with a fixing hole (24); the connecting pipe (4) is provided with an insert hole (23); and the insert rod (22), the through hole (25), the fixing hole (24) and the insert hole (23) correspond to each other.

6. The underground coal mine hydraulic fracturing drilling sealing device according to claim 3, characterized in that: The telescopic assembly comprises a square cavity (14), the screw hole rod (13) has a square cavity (14) formed inside, a square block (15) is movably sleeved inside the square cavity (14), a round rod (16) is fixed to the side of the square block (15), and the end of the round rod (16) passes through the screw hole rod (13) and is fixed to the cavity ring (17).

7. The underground coal mine hydraulic fracturing drilling sealing device according to claim 1, characterized in that: It also includes a sealing hole blocking protection mechanism; Wherein, the hole sealing and blocking protection mechanism comprises a hole sealing component and a blocking and protection component; The sealing assembly comprises a liquid injection pipe (28), an expansion hose (31), a side groove (29) and a liquid injection hole (30); the first hole sealer (2) and the second hole sealer (3) are both fixed with the liquid injection pipe (28) and the expansion hose (31); the first hole sealer (2) and the second hole sealer (3) are both provided with annular side grooves (29) and liquid injection holes (30) at equal intervals; the side grooves (29) are connected with the expansion hose (31) through the liquid injection hole (30).

8. The underground coal mine hydraulic fracturing drilling and sealing device according to claim 7, characterized in that: The blocking and protection component comprises a block (33), the block (33) is sleeved inside the side groove (29), a limiting hole (41) is provided inside the block (33), a side block (40) is movably sleeved inside the limiting hole (41), a slope block (32) is fixed to the side of the block (33), a fixing rod (39) is fixed to the side of the side block (40), one end of the fixing rod (39) passes through the slope block (32) and is fixed to the inner wall of the side groove (29), and a moving ring (34) is fixed to the side of the block (33).

9. The underground hydraulic fracturing drilling and sealing device of coal mine according to claim 8, characterized in that: A sleeve block (36) movably connected to the expansion hose (31) is fixed on the side of the movable ring (34), a rubber block (38) is fixed on the side of the sleeve block (36), a return spring (35) is fixed on the side block (40), and a fixing ring (37) is fixed on the end of the return spring (35). There are two fixing rings (37), which are respectively fixed on the first hole sealer (2) and the second hole sealer (3).

10. A method for using a hydraulic fracturing drilling and sealing device in an underground coal mine according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. First, press the cavity ring (17) and insert the connecting tube (4) on the first hole sealer (2) into the connector (1), so that the connecting tube (4) pushes the round head rod (18) to move, and the side plate (19) compresses the flexible spring (20). When the round head rod (18) corresponds to the round head hole (21), the flexible spring (20) squeezes the round head rod (18) through the side plate (19), and then the round head rod (18) moves into the round head hole (21); S2, then push the cavity ring (17), so that the round rod (16) drives the square block (15) to move along the inner wall of the square cavity (14), until the insertion rod (22) passes through the through hole (25) and is inserted into the interior of the fixing hole (24), so that the insertion rod (22) fixes the round head rod (18) through the fixing hole (24), and then insert the connecting pipe (4) on the second hole sealer (3) into the interior of the connector (1) in the same way; S3, when the connecting tubes (4) on the first hole sealer (2) and the second hole sealer (3) are both inserted into the connector (1), the double-axis motor (11) is started, the threaded rod (12) drives the two cavity rings (17) to move through the screw hole rod (13), and the cavity ring (17) drives the connecting tube (4) to move into the connector (1) and squeeze the rubber ring (27) through the round head rod (18), until the cavity ring (17) drives the retaining ring (26) to be in closed contact with the connector (1), and then the double-axis motor (11) is stopped, and at this time the insertion rod (22) is inserted into the inside of the insertion hole (23), thereby achieving the purpose of fixing and connecting the first hole sealer (2) and the second hole sealer (3); S4. Finally, the first and second sealers (2 and 3) are sent into the borehole of the coal seam through the drilling device, and water and other media are injected into the first and second sealers (2 and 3) through the high-pressure water injection pump, so that the first and second sealers (2 and 3) expand and seal the borehole. After the pressure in the borehole is increased by continuing to inject water and other media, the coal seam is fractured, and then the subsequent gas extraction work can be carried out.

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