Crushed and soft coal bed pneumatic closed coring device

Abstract

The utility model discloses a broken soft coal bed pneumatic airtight coring device which comprises a coring outer cylinder, a coring drill bit and an adapter. A pressing ball seat is arranged in the adapter, a locking mechanism core pipe is arranged in the lower end of the pressing ball seat in a sleeved mode, and the locking mechanism core pipe is further sleeved with a force storage mechanism body pipe capable of moving in the axial direction. The lower end of the power storage mechanism main body pipe is connected with the coring inner cylinder through a power storage mechanism main body pipe extension section capable of axially moving; a limiting step is arranged on the outer wall of the force storage mechanism body pipe, a locking sliding sleeve is further arranged outside the force storage mechanism body pipe in a sleeving mode, and a force storage spring is further arranged between the limiting step and the locking sliding sleeve in an abutting mode. A locking ball is embedded in the pipe wall of the lower end of the force storage mechanism body pipe and can axially limit the locking sliding sleeve. A sealing ball valve is arranged in the coring inner cylinder, and the pushing cylinder can be pushed by the locking sliding sleeve to move in the axial direction to close the sealing ball valve. The closed coring device solves the problems of hole spraying, hole collapse and the like when an existing closed coring device is used in a broken soft coal seam.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal mine safety and geological exploration, and relates to a pneumatic closed coring device for crushed soft coal seams. Background Art

[0002] my country's coal seams are characterized by complex geological conditions, characterized by coal fragmentation, low permeability, and high gas pressure. Crushed, soft coal seams are extremely common in high-gas mines and those with coal and gas outbursts. Coal seam gas content is a fundamental parameter for predicting and preventing mine gas hazards, as well as for evaluating and developing gas resources. Crushed, soft, and gassy coal seams are prone to water-induced blowouts and collapse, making it difficult to use water as a medium for coring and hydraulically sealing the bottom of the core hole. Existing closed coring devices, however, mostly use water as a medium. Therefore, deep-hole, fixed-point, closed coring technology is urgently needed in mines mining crushed, soft, and gassy coal seams to accurately detect gas occurrence information over long distances and over large areas underground, ensuring safe and efficient mine production. Utility Model Content

[0003] In view of the defects and deficiencies in the prior art, the utility model provides a pneumatic closed coring device for crushed soft coal seams to solve the above-mentioned deficiencies in the prior art.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0005] A pneumatic closed coring device for crushed soft coal seams comprises a coring outer barrel, with a coring drill bit and an adapter provided at both ends of the coring outer barrel; the lower end of the adapter extends into the coring outer barrel, and the lower end of the coring outer barrel extends into the coring drill bit; a pressure ball seat is provided in the adapter, and a sealing ball is provided in the pressure ball seat;

[0006] The lower end of the pressure ball seat is sleeved with a locking mechanism core tube, and the outer portion of the locking mechanism core tube is further sleeved with an axially movable force storage mechanism main body tube; the lower end of the force storage mechanism main body tube is connected to the core inner cylinder via an axially movable force storage mechanism main body tube extension section;

[0007] A limiting step is provided on the outer wall of the main tube of the force storage mechanism, a locking sleeve is also sleeved on the outer surface of the main tube of the force storage mechanism, and a force storage spring is also arranged between the limiting step and the locking sleeve; a locking ball is embedded in the tube wall of the lower end of the main tube of the force storage mechanism, and the locking ball can axially limit the locking sleeve;

[0008] An auxiliary spring is also sheathed on the outer surface of the core tube of the locking mechanism, the upper end of the auxiliary spring is in contact with the lower end surface of the pressing ball seat, and the lower end is in contact with the upper end surface of the limiting step; an unlocking groove capable of accommodating the locking ball is opened on the outer wall of the lower end of the core tube of the locking mechanism;

[0009] A push cylinder is coaxially sleeved on the outside of the lower end of the locking sleeve, and the extended section of the main tube of the power storage mechanism and the core inner cylinder are both sleeved in the push cylinder; a sealing ball valve is provided in the core inner cylinder, and the push cylinder can move axially to close the sealing ball valve under the push of the locking sleeve.

[0010] The utility model also has the following technical features:

[0011] Specifically, the main tube of the power storage mechanism includes a first connecting section and a second connecting section that are integrally connected. The upper end of the first connecting section extends into the adapter; the second connecting section is fitted with the core tube of the locking mechanism, and the lower end of the second connecting section extends into the locking sleeve; the outer diameter of the first connecting section is larger than the outer diameter of the second connecting section, and the connection between the first connecting section and the second connecting section forms the limiting step;

[0012] The top end of the force storage spring is in contact with the lower end surface of the limiting step, and the bottom end is in contact with the upper end surface of the locking sliding sleeve.

[0013] Furthermore, a through mounting hole is opened on the tube wall at the lower end of the main tube of the power storage mechanism, and the locking ball is embedded in the mounting hole.

[0014] Furthermore, an unlocking groove capable of engaging with the locking ball is provided on the inner wall of the locking sleeve.

[0015] Furthermore, a sealing knob is provided at the top of the sealing ball valve, and the sealing knob passes through a through hole provided on the wall of the core inner tube;

[0016] When the pushing cylinder moves in the axial direction, the sealing knob can be pushed to rotate to close the sealing ball valve.

[0017] Furthermore, the pressing ball seat is threadedly connected to the core tube of the locking mechanism; the main tube of the power storage mechanism is threadedly connected to the adapter; and the locking sliding sleeve is threadedly connected to the pushing cylinder.

[0018] Furthermore, the coring drill bit includes a hollow drill body with two ends open; an inner hole channel is axially arranged inside the hollow drill body, and a plurality of cutting wings are radially arranged at the bottom end.

[0019] The utility model also discloses a pneumatic closed coring method for a crushed soft coal seam, which is implemented by the pneumatic closed coring device for a crushed soft coal seam as described above, and comprises the following steps:

[0020] Step 1: Connect the adapter to the coring drill pipe, and drill the pneumatic closed coring device for the broken soft coal seam from the orifice to the preset coring point. During the drilling process, the sealing ball valve remains open;

[0021] Step 2: Insert a sealing ball into the core drill pipe and inject high-pressure gas into the core drill pipe to pressurize it. The core tube of the locking mechanism moves downward under the push of the sealing ball, and the unlocking groove moves to the position of the locking ball. The bottom end of the locking ball enters the unlocking groove; the locking sleeve separates from the main tube of the power storage mechanism, and the locking sleeve moves downward under the push of the power storage spring, thereby driving the push cylinder downward and rotating the sealing knob to close the sealing ball valve;

[0022] Step 3: Remove all drilling tools from the hole in sequence, remove the coring inner tube, and complete the closed coring.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] The utility model solves the technical problems of blowholes and collapsed holes in the application of the prior art in broken soft coal seams through pneumatic drilling and gas-driven in-situ sealing of the bottom of the coal core hole. In the closed coring process, there is no need for a high-pressure power source such as a high-pressure water pump, and the dry environment of the entire hole section can be maintained during pneumatic drilling, meeting the needs of collecting dry coal samples in mines, ensuring that gas- and water-retaining coal samples with in-situ gas occurrence and original moisture content are drilled, making the measured values ​​of gas content, moisture content, etc. more real and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the device of the utility model.

[0026] The symbols in the figure represent:

[0027] 1-coring outer cylinder, 2-coring drill bit, 3-adapter, 4-pressure ball seat, 5-sealing ball, 6-locking mechanism core tube, 7-energy storage mechanism main tube, 8-energy storage mechanism main tube extension section, 9-coring inner cylinder, 10-locking sliding sleeve, 11-pushing cylinder, 12-energy storage spring, 13-locking ball, 14-auxiliary spring, 15-sealing ball valve; 201-hollow drill bit body, 202-inner hole channel, 203-cutting wing; 151-sealing knob; 701-limiting step, 702-first connecting section, 703-second connecting section; 1001-unlocking groove.

[0028] The present invention will be described in detail below with reference to the accompanying drawings and specific implementation methods. DETAILED DESCRIPTION

[0029] In accordance with the above technical solution, the following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications based on the technical solution of this application fall within the scope of protection of the present invention. The present invention will be further described in detail below in conjunction with the embodiments.

[0030] When describing the directions of the present invention, the terms "upper", "lower", "front", "back", "left", "right" and the like to indicate directions or positional relationships are only used to facilitate the description of the present invention and simplify the description, and do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention. Figure 1 The directions shown are described.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Unless otherwise specified, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to the specific circumstances.

[0032] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0033] The technical concept of this utility model is as follows: the force storage mechanism is composed of a force storage mechanism main tube, a force storage spring, and a locking sleeve; the locking mechanism is composed of a locking mechanism core tube, an auxiliary spring, and a locking ball. During installation, the force storage spring is compressed, thereby obtaining sufficient driving force for later use by the force storage spring. The locking mechanism completes the limited connection between the force storage mechanism main tube and the locking sleeve to maintain the compression of the force storage spring, thereby storing driving force for standby use. The utility model employs a "switch" principle, using small energy to activate large energy. Low-pressure gas pushes the sealing ball, which is then triggered by the axial movement of the locking mechanism core tube. At the moment the locking sleeve separates from the force storage mechanism main tube, the elastic force provided by the force storage spring pushes the push barrel downward, thereby shearing the sealing ball valve in the coring inner barrel and sealing the coal core. This ensures that the pneumatic closed coring device can drill water-retaining coal samples with original water content in broken soft coal seams. No high-pressure power source such as a high-pressure pump is required; the device can be triggered by the compressed air system commonly available underground.

[0034] The main body of the pneumatic closed coring device adopts a three-tube structure, consisting of an outer coring tube, a push tube, and an inner coring tube. The inner coring tube adopts a "ball valve seal, integrated coring / desorption" structural design. "Ball valve seal" means that the closed coring device seals the coal sample with a sealed ball valve closure method, with a pressure maintenance capacity of no less than 10MPa. "Integrated coring / desorption" means that the inner coring tube is used for both collecting coal samples in the borehole and directly for gas desorption testing after sampling. Due to the provision of a locking mechanism and a force storage mechanism, the pneumatic closed coring device has a simpler structure, eliminating the need for components such as hydraulic piston cylinders, sealing rings, and pins, and is quicker to disassemble, assemble, and maintain.

[0035] The high-pressure gas in the present invention includes high-pressure air or high-pressure nitrogen.

[0036] Example 1:

[0037] Following the above technical solution, Figure 1 As shown, this embodiment provides a pneumatic closed coring device for broken soft coal seams, including a coring outer cylinder 1, the two ends of the coring outer cylinder 1 are coaxially connected and provided with a coring drill bit 2 and an adapter 3, and the adapter 3, the coring outer cylinder and the coring drill bit 2 are coaxially connected in sequence from top to bottom; the lower end of the adapter 3 extends into the coring outer cylinder 1, and the lower end of the coring outer cylinder 1 extends into the coring drill bit 2; a pressure ball seat 4 is provided in the adapter 3, and an inner cavity is provided through the pressure ball seat 4, and a limiting inclined surface is provided in the inner cavity, which can limit the sealing ball 5 put into the inner cavity, and a locking mechanism core tube 6 is sleeved on the lower end of the pressure ball seat 4, and the upper end of the locking mechanism core tube 6 extends into the pressure ball seat 4.

[0038] An axially movable power storage mechanism main body tube 7 is provided on the outer shell of the locking mechanism core tube 6; the lower end of the power storage mechanism main body tube 7 is coaxially connected to the axially movable power storage mechanism main body tube extension section 8, and the lower end of the power storage mechanism main body tube extension section 8 is coaxially connected to the coring inner tube 9; the presence of the power storage mechanism main body tube 7, the power storage mechanism main body tube extension section 8 and the locking sliding sleeve 10 realizes the connection between the adapter 1 and the pushing tube 7, and the power storage mechanism main body tube extension section 8 can play a role in straightening the coring inner tube 9.

[0039] A limiting step 701 is provided on the outer wall of the main tube 7 of the force storage mechanism, and a locking sleeve 10 is also sleeved on the outside of the main tube 7 of the force storage mechanism; a force storage spring 12 is also arranged between the limiting step 701 and the locking sleeve 10, and the locking sleeve 10 can move axially under the elastic force of the force storage spring 12; a locking ball 13 is embedded on the tube wall of the lower end of the main tube 7 of the force storage mechanism, and the locking ball 13 can axially limit the locking sleeve 10, thereby realizing the connection between the main tube 7 of the force storage mechanism and the locking sleeve 10.

[0040] An auxiliary spring 14 is also sheathed on the outer surface of the core tube 6 of the locking mechanism. The upper end of the auxiliary spring 14 abuts against the lower end surface of the pressing ball seat 4, and the lower end of the auxiliary spring 14 abuts against the upper end surface of the limiting step 701. An unlocking groove capable of accommodating the locking ball 13 is formed on the outer wall of the lower end of the core tube 6 of the locking mechanism. When the locking ball 13 partially enters the unlocking groove, the locking sleeve 10 can be unlocked, and the locking sleeve 10 can move axially downward under the elastic force of the storage spring 12.

[0041] A push cylinder 11 is coaxially sleeved on the outside of the lower end of the locking sleeve 10, and the extended section 8 of the main tube of the power storage mechanism and the coring inner cylinder 9 are both sleeved in the push cylinder 11; a sealing ball valve 15 is provided at one end of the coring inner cylinder 9 close to the coring drill bit, and the push cylinder 11 can move axially under the push of the locking sleeve 10, thereby closing the sealing ball valve 15.

[0042] As a preferred solution of this embodiment, the main tube 7 of the force storage mechanism includes a first connecting section 702 and a second connecting section 703 that are integrally connected. The upper end of the first connecting section 702 extends into the adapter 3, and the outer wall of the first connecting section 702 is threadedly connected to the inner wall of the adapter 3. An installation cavity is formed between the first connecting section 702 and the core tube 6 of the locking mechanism, and the auxiliary spring 14 is arranged in the installation cavity; the second connecting section 703 is fitted with the core tube 6 of the locking mechanism; the outer diameter of the first connecting section 702 is larger than the outer diameter of the second connecting section 703, and a limiting step 701 is formed at the connection between the first connecting section 702 and the second connecting section 703; the top end of the force storage spring 12 is in contact with the lower end face of the limiting step 701, and the lower end is in contact with the upper end face of the locking sleeve 10.

[0043] As a preferred solution of this embodiment, a through mounting hole is opened on the lower end wall of the main tube 7 of the power storage mechanism, and the locking ball 13 is embedded in the mounting hole.

[0044] As a preferred solution of this embodiment, an unlocking groove 1001 is formed on the inner wall of the locking sleeve 10 to engage with the locking ball 13. When the locking ball 13 is engaged with the unlocking groove 1001, the locking sleeve 10 is axially limited to prevent the locking sleeve 10 from moving axially.

[0045] As a preferred solution of this embodiment, a sealing knob 151 is provided at the top of the sealing ball valve 15, and the sealing knob 151 passes through a through hole opened on the wall of the core inner tube 9;

[0046] During the process of the pushing cylinder 11 moving in the axial direction, the cylinder wall of the pushing cylinder 11 can push the sealing knob 151 to rotate, so as to close the sealing ball valve 15 .

[0047] In this embodiment, the sealing ball valve 15 is provided with two sealing knobs 151 at opposite ends along the radial direction of the coring inner cylinder 9 .

[0048] As a preferred solution of this embodiment, the pressing ball seat 4 is threadedly connected to the locking mechanism core tube 6; the power storage mechanism main tube 7 is threadedly connected to the adapter 3; and the locking sliding sleeve 10 is threadedly connected to the pushing cylinder 11.

[0049] As a preferred solution of this embodiment, the core drill bit 2 includes a hollow drill body 201 with open ends; an inner hole channel 202 is axially arranged inside the hollow drill body 201, and multiple cutting wings 203 are radially arranged at the bottom end of the hollow drill body 201.

[0050] The process of using this device is as follows:

[0051] The pneumatic closed coring device is sent to the coring position in the borehole, the rear end of the coring drill pipe is connected to the downhole compressed air system or air compressor, and the compressed air is used for coring drilling, and the crushed debris ground by the coring drill bit 2 is discharged out of the hole, and the sealing ball 5 is put into the coring drill pipe. High-pressure gas is injected into the coring drill pipe for pressurization. The core tube 6 of the locking mechanism moves downward under the push of pressure, and the unlocking groove moves to the position of the locking ball 13, and the bottom end of the locking ball 13 enters the unlocking groove; the locking sleeve 10 is separated from the main tube 7 of the power storage mechanism, and the locking sleeve 10 moves downward under the push of the power storage spring 12, driving the push cylinder 11 downward, the sealing knob 151 is rotated, and the sealing ball valve 15 is closed to complete the closed coring.

[0052] The utility model solves the technical problems of blowholes and collapsed holes in the application of the prior art in broken soft coal seams by pneumatic core drilling and gas-driven in-situ sealing of the coal core hole bottom. It does not require a high-pressure power source such as a high-pressure water pump, and can maintain a dry environment in the entire hole section during pneumatic drilling, meeting the needs of collecting dry coal samples in mines, ensuring that gas- and water-retaining coal samples with in-situ gas occurrence and original moisture content are drilled, making the measured values ​​of gas content, moisture content, etc. more real and accurate.

[0053] The above implementation process is merely an example to clearly illustrate the present application and is not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present application.

Claims

1. A pneumatic closed coring device for a broken soft coal seam, comprising a coring outer cylinder (1), wherein both ends of the coring outer cylinder (1) are provided with a coring drill bit (2) and an adapter (3); the lower end of the adapter (3) extends into the coring outer cylinder (1), and the lower end of the coring outer cylinder (1) extends into the coring drill bit (2); a pressure ball seat (4) is provided in the adapter (3), and a sealing ball (5) is provided in the pressure ball seat (4), wherein the device is characterized in that: The lower end of the pressure ball seat (4) is sheathed with a locking mechanism core tube (6), and the outer portion of the locking mechanism core tube (6) is also sheathed with an axially movable force storage mechanism main body tube (7); the lower end of the force storage mechanism main body tube (7) is connected to a core inner tube (9) via an axially movable force storage mechanism main body tube extension section (8); The outer wall of the main tube (7) of the power storage mechanism is provided with a limiting step (701), the outer surface of the main tube (7) of the power storage mechanism is also provided with a locking sleeve (10), and a power storage spring (12) is also provided between the limiting step (701) and the locking sleeve (10); a locking ball (13) is embedded in the lower end wall of the main tube (7) of the power storage mechanism, and the locking ball (13) can axially limit the locking sleeve (10); The locking mechanism core tube (6) is also provided with an auxiliary spring (14), the upper end of the auxiliary spring (14) is in contact with the lower end surface of the pressing ball seat (4), and the lower end of the auxiliary spring (14) is in contact with the upper end surface of the limiting step (701); an unlocking groove capable of accommodating the locking ball (13) is provided on the outer wall of the lower end of the locking mechanism core tube (6); A push cylinder (11) is coaxially sleeved on the extension section (8) of the main pipe of the power storage mechanism and the core inner cylinder (9), and a sealing ball valve (15) is provided in the core inner cylinder (9). The push cylinder (11) can close the sealing ball valve (15) by axial movement. A push cylinder (11) is coaxially sleeved on the outer side of the lower end of the locking sleeve (10), and the extended section (8) of the main tube of the power storage mechanism and the core inner cylinder (9) are both sleeved in the push cylinder (11); a sealing ball valve (15) is provided in the core inner cylinder (9), and the push cylinder (11) can move axially to close the sealing ball valve (15) under the push of the locking sleeve (10).

2. The pneumatic closed coring device for crushed soft coal seams according to claim 1, characterized in that: The power storage mechanism main body tube (7) comprises a first connecting section (702) and a second connecting section (703) which are connected in an integrated manner, wherein the upper end of the first connecting section (702) extends into the adapter (3); the second connecting section (703) is fitted with the locking mechanism core tube (6), and the lower end of the second connecting section (703) extends into the locking sleeve (10); the outer diameter of the first connecting section (702) is larger than the outer diameter of the second connecting section (703), and the limiting step (701) is formed at the connection between the first connecting section (702) and the second connecting section (703); The top end of the force storage spring (12) is in contact with the lower end surface of the limiting step (701), and the bottom end is in contact with the upper end surface of the locking sliding sleeve (10).

3. The pneumatic closed coring device for crushed soft coal seams according to claim 1, characterized in that: A through mounting hole is provided on the lower end wall of the main tube (7) of the power storage mechanism, and the locking ball (13) is embedded in the mounting hole.

4. The pneumatic closed coring device for crushed soft coal seams according to claim 1, characterized in that: An unlocking groove (1001) capable of engaging with the locking ball (13) is provided on the inner wall of the locking sliding sleeve (10).

5. The pneumatic closed coring device for crushed soft coal seams according to claim 1, characterized in that: The top end of the sealing ball valve (15) is provided with a sealing knob (151), and the sealing knob (151) passes through a through hole provided on the wall of the core inner tube (9); During the process of the pushing cylinder (11) moving in the axial direction, the sealing knob (151) can be pushed to rotate so as to close the sealing ball valve (15).

6. The pneumatic closed coring device for crushed soft coal seams according to claim 1, characterized in that: The pressing ball seat (4) is threadedly connected to the locking mechanism core tube (6); the power storage mechanism main body tube (7) is threadedly connected to the adapter (3); and the locking sliding sleeve (10) is threadedly connected to the pushing cylinder (11).

7. The pneumatic closed coring device for crushed soft coal seams according to claim 1, characterized in that: The coring drill bit (2) comprises a hollow drill bit body (201) with two ends open; an inner hole channel (202) is provided in the axial direction inside the hollow drill bit body (201); and a plurality of cutting wings (203) are provided in the radial direction at the bottom end of the hollow drill bit body (201).

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