A deep hole closed pressure maintaining sampler for coal mine

Abstract

A deep hole sealed pressure-maintaining sampler for coal mines, comprising an outer tube assembly, a core shaft, a sample storage assembly and a drive assembly, wherein the core shaft is divided into three parts: a first shaft section, a second shaft section and a third shaft section, a first boss is arranged between the second shaft section and the third shaft section, the drive assembly comprises a first piston, a second piston, a propulsion sleeve and a transmission mechanism capable of controlling the opening and closing of the sample storage assembly, a first piston is arranged between the second shaft section and the outer sleeve, a propulsion sleeve is sleeved on the outer side of the core shaft, one end of the propulsion sleeve abuts against the first piston, and the other end protrudes toward the core shaft and abuts against the transmission mechanism, and a second piston is arranged between the third shaft section and the propulsion sleeve. Compared with the prior art, the present application adopts a double piston and a boss arranged on the shaft section to enable the piston to move twice independently, so that the sample storage assembly can realize the conversion of the closed, open and closed states, prevent the sample storage assembly from being contaminated before sampling, and make the sample storage assembly sealed after sampling.

Description

Technical Field

[0001] The invention belongs to the technical field of coal seam gas content detection, and in particular relates to a deep hole closed pressure-maintaining sampler for coal mines. Background Art

[0002] The gas content of coal seams is an important indicator for measuring the gas occurrence of coal seams. It is an important reference for predicting the gas outburst volume of mines, guiding the design of coal mine gas extraction, and evaluating the effect of gas control. At present, there are two main methods for determining the gas content of coal seams: indirect method and direct method. The indirect method uses the Langmuir formula to calculate the gas content of coal seams based on the measured coal seam gas pressure, coal adsorption constant, industrial analysis and other parameters. This method has a long test cycle and high cost, and is rarely used on coal mine sites. In actual coal seam gas content determination, the direct method is mainly used. The direct method is to collect coal dust at the orifice or drill coal core samples at the bottom of the hole, and measure and calculate the gas loss, desorption gas and residual gas in the sampling process. The sum of these three is the coal seam gas content. The coal dust is collected at the hole mouth by pressing air into the hole to discharge coal dust. The process is simple and easy to operate, but the residual coal dust on the hole wall has a greater impact on the sampling accuracy and the integrity of the coal sample is poor, especially in the case of soft coal seams or deep drilling. The residual coal dust on the hole wall has a greater impact on the accuracy of the content. This sampling method cannot guarantee the acquisition of coal samples at a specified depth, and is mainly used for shallow hole coal sampling to determine gas content. The method of drilling coal cores to determine the gas content refers to first using a drill to open a hole to a predetermined depth, and then replacing it with a sampler to drill the coal core. The sampler generally includes a core barrel and a sampling drill bit that matches the core barrel. The existing samplers are generally open-topped, and it is generally difficult to meet the requirements of closed pressure-maintaining sampling, that is, the core barrel is sealed before sampling, opened during sampling, and sealed again after sampling. This makes it easy for the broken coal and rock chips in the hole to be poured into the sampling barrel before reaching the bottom of the hole for sampling during the process of sending the open sampler into the borehole, so that the sample taken by the sampler contains a large amount of drilling slag. The deeper the borehole, the more slag blocks there are in the sample, and the less effective sampling. In addition, since it cannot be sealed during the drilling process, the coal sample is exposed, resulting in the loss of gas analyzed from the coal sample, which is difficult to measure, affecting the accuracy of the determination of the gas content of the coal sample, resulting in large errors in the results of the measured coal seam gas content, which is not conducive to the formulation and implementation of gas prevention and control measures. Especially when sampling at a depth greater than 30 meters, the greater the sampling depth, the longer the coal sample is exposed during the re-drilling process, and the greater the gas loss. Therefore, how to meet the requirements of deep hole closed pressure sampling and reduce the gas loss during the sampling process is the key to accurately measuring the gas content of deep hole coal seams.

[0003] In order to solve the above problems, the patent application number 201610072834.2 discloses a closed gas sampling device, comprising an outer tube, an inner tube and a second-layer tube, wherein the outer tube comprises a connecting mandrel for controlling the mud inlet and outlet channels, a drill bit and a connecting pipe assembly between the connecting mandrel and the drill bit, and the inner tube comprises at least a connecting sleeve, an upper ball valve, a sealing tube and a lower ball valve, one end of the connecting sleeve is rotatably sleeved on the connecting mandrel, a core tube is provided between the upper ball valve and the lower ball valve as a storage carrier for the core, and the closing of the upper ball valve and the lower ball valve can seal the core tube, the end of the second-layer tube abuts against the connecting mandrel and can move forward and backward under the control of the connecting mandrel, and a control element for controlling the opening and closing of the upper ball valve and the lower ball valve is provided at the front end to realize the opening and closing of the upper and lower ball valves by moving forward or backward. However, the technical solution provided by the patent has certain technical problems. When the sampling device is drilling into the ground, the lower ball valve of the inner tube of the sampling device is in an open state, which allows other impurities to enter the core tube during the drilling process, resulting in sample contamination and affecting the detection effect. When closing the ball valve, a rubber ball needs to be placed in the connecting spindle. In theory, when the mud hits the rubber ball, the rubber ball should be stably located above the tapered hole under the action of the impact force so that the rubber ball can block the tapered hole, thereby changing the flow path of the mud to provide power for the closing of the ball valve. However, according to the research on fluid mechanics, when the mud hits the rubber ball, turbulence will occur near the rubber ball. At this time, the impact force exerted by the mud on the rubber ball is not stable and completely along the center of the connecting spindle. When the spindle is downward, the rubber ball cannot be completely and stably located above the tapered hole to completely block the tapered hole, resulting in a failure to provide a stable power source for closing the ball valve, thereby affecting the stability and reliability of the sampling work of the sampling device; since the sample contains certain gas components, part of these gases are adsorbed by the sample, and part of them are desorbed from the sample and remain in the core tube, so when the sample is taken out of the sampling device after the sampling work is completed, it is necessary to ensure that the gas will not escape, but the sealing effect of the core tube of this patent is achieved by closing the upper ball valve and the lower ball valve. When taking out the sample, the two ball valves of this patent will rotate synchronously, and the desorbed gas cannot be directly collected. At this time, the desorbed gas in the sample is easy to escape, resulting in problems in the sampling work. Summary of the invention

[0004] The technical problem to be solved by the present invention is that during the sampling process of an open sampler, broken coal and rock chips in the borehole are easily introduced into the sampler, resulting in contamination of the coal sample. In order to solve the above problem, the present invention provides a deep hole closed pressure maintaining sampler for coal mines, which adopts a double piston structure, a thrust sleeve and a transmission mechanism to ensure that the sample storage assembly is in a closed state during the descending process of the sampler and one piston drives the sample storage assembly to switch to an open state when sampling begins. After the sampling is completed, the other piston drives the sample storage assembly to close again, so that the sample will not be contaminated.

[0005] The object of the present invention is achieved in the following manner:

[0006] A deep hole closed pressure-maintaining sampler for coal mines, comprising an outer tube assembly, a core shaft, a sample storage assembly and a driving assembly, the outer tube assembly comprising a drill pipe joint with a hollow structure, an outer sleeve and a drill bit connected in sequence, a core shaft and a sample storage assembly are arranged in the outer tube assembly, one end of the core shaft is connected to the drill pipe joint, and the other end is connected to the sample storage assembly, a driving assembly is arranged between the core shaft and the sample storage assembly and the outer sleeve, a channel for water to flow in and out is arranged in the core shaft, the core shaft is divided into three parts: a first shaft section, a second shaft section and a third shaft section, a first boss is arranged between the second shaft section and the third shaft section, the driving assembly comprises a first piston, a second piston, a propulsion sleeve and a transmission mechanism capable of controlling the opening and closing of the sample storage assembly, a first piston is arranged between the second shaft section and the outer sleeve, a propulsion sleeve is sleeved on the outside of the core shaft, one end of the propulsion sleeve abuts against the first piston, and the other end protrudes toward the core shaft and abuts against the transmission mechanism, and a second piston is arranged between the third shaft section and the propulsion sleeve.

[0007] A first flow hole is arranged inside the first shaft section and the second shaft section of the mandrel, and a second flow hole is arranged inside the second shaft section of the mandrel.

[0008] A second boss is arranged at the front end of the drill rod joint, and a gap exists between the second boss and the opening of the first flow hole located in the second shaft section.

[0009] The sample storage assembly includes a coal sample tube base, a coal sample tube, a ball valve body, a ball valve core and a ball valve cover. One end of the coal sample tube base is connected to the core shaft, and the other end is connected to the coal sample tube. The coal sample tube is connected to the ball valve body. A ball valve core is arranged in the ball valve body. A gear that can drive the ball valve core to open and close is arranged on the side of the ball valve core.

[0010] A first screw hole and a second screw hole are respectively arranged at both ends of the coal sample tube base, the first screw hole and the second screw hole are connected through a first through hole, a clamping screw, a compression spring and a sealing steel ball which can be pushed by the compression spring to close the first through hole are arranged in sequence in the second screw hole, and a second through hole is axially arranged in the clamping screw.

[0011] The transmission mechanism capable of controlling the opening and closing of the sample storage component includes a propulsion rack tube and a propulsion rack. The propulsion rack tube is sleeved on the outside of the sample storage component, one end of the propulsion rack tube is against the propulsion sleeve, the propulsion rack tube is connected to the propulsion rack, and the propulsion rack is meshed with the gear.

[0012] A sealing ring is arranged at the position where the outer side of the drill pipe joint contacts the outer casing, sealing rings are arranged on the inner and outer sides of the first piston, sealing rings are arranged on the inner and outer sides of the second piston, a sealing ring is arranged on the outer side of the thrust casing, a sealing ring is arranged at the position where the outer side of the coal sample tube base contacts the coal sample tube, a sealing ring is arranged at the position where the outer side of the ball valve body contacts the coal sample tube, and a sealing ring is arranged at the position where the ball valve body and the ball valve gland contact.

[0013] Compared with the prior art, the present application adopts a double-piston structure and cooperates with the first boss set on the shaft section to enable the piston to move twice independently. After one piston moves to drive the opening and closing of the sample storage component, the piston is restricted by the boss and no longer moves, so that the sample storage component can remain in a set state for a certain period of time. When the opening and closing state of the sample storage component needs to be converted, the other piston is driven to move. At this time, the first piston will not move due to the restriction of the first boss. After the other piston moves, it drives the sample storage component to convert the opening and closing state. The secondary conversion of the opening and closing state of the sample storage component is realized in the above manner. In the prior art, the piston can only move on the same path. After the piston starts to move, the opening and closing state of the sample storage component can be maintained only when it moves to the end of the path, so that the sample storage component cannot be stably in the three states of closed, open, and closed in sequence within a certain period of time, and can only complete one conversion of the opening and closing state of the sample storage component. After the piston in the prior art is driven, in order to ensure that the sampler is in a closed state when the final sampling is completed, the sampler of the prior art enters the It needs to be in an open state before arriving at the sampling area, and can be switched to a closed state only after the sampling is completed. Since the sample storage component of the present application can realize the conversion of three states, the sample storage component can be set to a closed state in the initial state to prevent the inside of the sample storage component from being contaminated. When the present application reaches the area where sampling is required, after the first piston moves and pushes the push sleeve to move a certain distance, the push sleeve drives the transmission mechanism that can control the opening and closing of the sample storage component to realize the conversion of the opening and closing state of the sample storage component, so that the sample storage component switches from the closed state to the open state, and then the sampling work is carried out. After the sampling is completed, the second piston moves. When the second piston contacts the end of the push sleeve that protrudes toward the core shaft, the second piston pushes the push sleeve to continue to move, so that the push sleeve drives the transmission mechanism that can control the opening and closing of the sample storage component to realize the conversion of the opening and closing state of the sample storage component again. The sample storage component is converted from the open state to the closed state, so that the sample storage component is in a sealed and pressure-maintaining state, thereby ensuring the effectiveness of the coal sample taken, improving the working efficiency of the sampler, and improving the accuracy of the gas content determination results of the coal sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] Figure 2 yes Figure 1Schematic diagram of the enlarged X region.

[0016] Figure 3 yes Figure 1 Enlarged schematic diagram of the Y region in the middle.

[0017] Figure 4 yes Figure 1 Schematic diagram of the top view of the meshing part of the propulsion rack and gear.

[0018] In the figure, 1 is the drill pipe joint; 2 is the outer sleeve; 3 is the core shaft; 301 is the first shaft section; 302 is the second shaft section; 303 is the third shaft section; 4 is the first piston; 5 is the second piston; 6 is the push sleeve; 7 is the push rack tube; 8 is the coal sample tube base; 9 is the sealing steel ball; 10 is the compression spring; 11 is the clamping screw; 12 is the coal sample tube; 13 is the push rack; 14 is the gear; 15 is the sealing ring; 16 is the outer drill bit; 17 is the inner drill bit; 18 is the ball valve body; 19 is the ball valve core; 20 is the ball valve cover; 21 is the first boss; 22 is the second boss; 23 is the first flow hole; 24 is the opening of the first flow hole located in the second shaft section; 25 is the second flow hole; 26 is the opening of the second flow hole located in the second shaft section; 27 is the first screw hole; 28 is the second screw hole; 29 is the first through hole; 30 is the second through hole; 31-38 are all sealing rings. DETAILED DESCRIPTION

[0019] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. It should be noted that the words "inside" and "outside" used in the following description refer to the direction toward or away from the geometric center of a specific component, respectively, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. "Front" is the direction where the drill bit is located, and "rear" is the direction where the drill pipe joint 1 is located.

[0020] like Figure 1As shown in —4, a deep hole closed pressure-maintaining sampler for coal mines comprises an outer tube assembly, a core shaft 3, a sample storage assembly and a drive assembly. The outer tube assembly comprises a drill pipe joint 1, an outer sleeve 2 and a drill bit connected in sequence. The drill pipe joint 1 is a hollow structure. The hollow structure refers to a cavity that can connect the two ends of the component and is arranged axially inside the component. The cavity is the hollow area of ​​the hollow structure. The hollow area of ​​the drill pipe joint 1 refers to the cavity inside the drill pipe joint 1 that connects the front and rear end surfaces of the drill pipe joint 1. The hollow area of ​​the drill pipe joint 1 forms a channel that allows high-pressure water to pass through. One end of the drill pipe joint 1 is used The outer tube assembly is connected to the drill pipe, and an outer sleeve 2 is sleeved on the outside of the other end. One end of the outer sleeve 2 is connected to the drill pipe joint 1, and the other end of the outer sleeve 2 is connected to the drill bit. The drill bit includes an outer drill bit 16 and an inner drill bit 17. The inner drill bit 17 is arranged on the inner side of the outer drill bit 16. The double-layer drill bit structure formed by the inner drill bit 17 and the outer drill bit 16 can improve the sampling efficiency of the coal sample. At the same time, the inner drill bit 17 and the outer drill bit 16 are both hollow structures, and the hollow areas of the inner drill bit 17 and the outer drill bit 16 form a channel through which the coal sample can pass; a core shaft 3 and a sample storage component are arranged in the outer tube assembly, and the outer tube assembly is a hollow structure A space of suitable size is provided in the vicinity of the axis for arranging the mandrel 3 and the sample storage assembly. One end of the mandrel 3 is connected to the drill pipe joint 1, and the other end is connected to the sample storage assembly. A driving assembly is provided between the mandrel 3 and the sample storage assembly and the outer sleeve 2. A space of suitable size is provided between the mandrel 3 and the sample storage assembly and the outer sleeve 2 according to the actual size of the driving assembly so that the driving assembly can be provided between the mandrel 3 and the sample storage assembly and the outer sleeve 2; a channel for water flow in and out is provided in the mandrel 3, and the mandrel 3 is divided into three parts: a first shaft section 301, a second shaft section 302 and a third shaft section 303. The first The diameters of the shaft segment 301, the second shaft segment 302 and the third shaft segment 303 need to be selected in appropriate sizes according to actual needs. A first boss 21 is set between the second shaft segment 302 and the third shaft segment 303. The first shaft segment 301 is connected to the drill pipe joint 1. In the relatively optimal case, the external thread set on the outer side of the first shaft segment 301 and the internal thread set on the inner side of the drill pipe joint 1 are fully meshed, so that the first shaft segment 301 can be threadedly connected to the drill pipe joint 1 and the first shaft segment 301 is completely located in the hollow area of ​​the drill pipe joint 1. The third shaft segment 303 of the core shaft 3 is connected to the sample storage component;The driving assembly includes a first piston 4, a second piston 5, a propulsion sleeve 6 and a transmission mechanism capable of controlling the opening and closing of the sample storage assembly. The first piston 4 is arranged between the second shaft section 302 and the outer sleeve 2. The first piston 4 is an annular structure and is sleeved on the second shaft section 302. The inner side of the first piston 4 is in close contact with the side surface of the second shaft section 302, and the outer side of the first piston 4 is in close contact with the inner side surface of the outer sleeve 2. The first piston 4 sleeve can slide along the second shaft section 302. The propulsion sleeve 6 is sleeved on the outer side of the core shaft 3. There is a certain space between the propulsion sleeve 6 and the core shaft 3 to form The outer side of the push sleeve 6 is close to the inner side of the outer sleeve 2, and the rear end of the push sleeve 6 is against the front side of the first piston 4, so that when the first piston 4 moves forward, it can generate a forward thrust on the push sleeve 6, thereby driving the push sleeve 6 to move forward synchronously, and the front end of the push sleeve 6 protrudes toward the core shaft 3 and presses against the transmission mechanism. A second piston 5 is arranged between the third shaft section 303 and the push sleeve 6. The second piston 5 is an annular structure and is sleeved on the third shaft section 303. The second piston 5 can slide back and forth along the third shaft section 303 The inner side of the second piston 5 is in close contact with the third shaft section 303 of the core shaft 3, and the outer side of the second piston 5 is in close contact with the inner side of the propulsion sleeve 6. When the second piston 5 moves forward along the third shaft section 303 to the front end of the area between the third shaft section 303 and the propulsion sleeve 6, the second piston 5 is blocked by the protrusion at the front end of the propulsion sleeve 6. At this time, if the second piston 5 continues to move forward, the protrusion at the front end of the propulsion sleeve 6 will be pushed forward by the second piston 5, so that the propulsion sleeve 6 moves forward with the forward movement of the second piston 5. The transmission mechanism is sleeved on the sample storage component. On the outside, the rear end of the transmission mechanism presses against the front end of the propulsion sleeve 6, so that when the propulsion sleeve 6 moves forward, it can generate a forward thrust on the transmission mechanism, thereby pushing the transmission mechanism to move forward with the forward movement of the propulsion sleeve 6, and the transmission mechanism can transmit power to the switch of the sample storage component, so that the transmission mechanism can control the opening and closing of the sample storage component. The principle of the transmission mechanism controlling the opening and closing of the sample storage component is that the propulsion sleeve 6 transmits power to the transmission mechanism, and the transmission mechanism transmits power to the sample storage component, so that the sample storage component obtains the power to switch the opening and closing state of the opening. ;

[0021] The first flow hole 23 is arranged inside the first shaft section 301 and the second shaft section 302 of the core shaft 3. A part of the first flow hole 23 is located inside the first shaft section 301, and another part is located inside the second shaft section 302. The opening of the rear side of the first flow hole 23 is located on the rear end surface of the first shaft section 301, and the opening of the front side of the first flow hole 23 is located on the side of the second shaft section 302, so that the first flow hole 23 can communicate with the area of ​​the internal cavity of the drill rod joint 1 and the area between the drill rod joint 1 and the first piston 4. The inner diameter size of the first flow hole 23 can be set according to actual working needs, and the number of openings of the first flow hole 23 can also be set according to actual working needs; the second shaft section 302 of the core shaft 3 A second flow hole 25 is provided in the part, and an opening 26 of the second flow hole located in the second shaft segment is provided on the side of the second shaft segment 302. The position of the opening needs to satisfy the condition that when the first piston 4 moves forward to the position of the first boss 21, the opening is just located on the rear side of the first piston 4, and the opening on the front side of the second flow hole 25 is located on the front end surface of the first boss 21, so that when the first piston 4 contacts the first boss 21, the second flow hole 25 can connect the area between the drill pipe joint 1 and the first piston 4 and the area between the second piston 5 and the first boss 21. The inner diameter size of the second flow hole 25 can be set according to actual work needs, and the number of openings of the second flow hole 25 can also be set according to actual work needs.

[0022] A second boss 22 is provided at the front end of the drill rod joint 1, and there is a gap between the second boss 22 and the opening 24 of the first circulation hole located in the second shaft section, so that when the rear end of the first piston 4 is attached to the front end of the drill rod joint 1, the opening 24 of the first circulation hole located in the second shaft section will not be blocked by the first piston 4, and the high-pressure water flow can enter the rear side of the first piston 4 along the first circulation hole 23, and then can apply a forward thrust to the first piston 4 from the rear side to push the first piston 4 to move forward.

[0023] The sample storage assembly includes a coal sample tube base 8, a coal sample tube 12, a ball valve body 18, a ball valve core 19 and a ball valve cover 20. The coal sample tube base 8 is used to carry the coal sample tube 12 and seal one end of the coal sample tube 12 to prevent leakage of coal samples and gas in the coal sample tube 12. The rear end of the coal sample tube base 8 is connected to the third shaft section 303 of the core shaft 3, the front end of the coal sample tube base 8 is connected to the rear end of the coal sample tube 12, the front end of the coal sample tube 12 is connected to the rear end of the ball valve body 18, the ball valve body 18 is connected to the ball valve cover 20, the ball valve core 19 is arranged between the ball valve body 18 and the ball valve cover 20, and a gear 14 is arranged on the side of the ball valve core 19. The gear 14 is connected to the rotating shaft of the ball valve core 19, so that when the gear 14 rotates, it can drive the ball valve core 19 to rotate synchronously, so that the ball valve core 19 can complete the switching between the open and closed states under the action of the gear 14.

[0024] A first screw hole 27 and a second screw hole 28 are respectively provided at the rear and front ends of the coal sample tube base 8. The first screw hole 27 is located at the rear end of the coal sample tube base 8, and the second screw hole 28 is located at the front end of the coal sample tube base 8. A through hole is provided inside the coal sample tube base 8, so that the first screw hole 27 and the second screw hole 28 are connected through the through hole. A clamping screw 11 is provided in the second screw hole 28, and the external thread of the clamping screw 11 matches the internal thread of the second screw hole 28, so that the clamping screw 11 can be rotated into the second screw hole 28. The clamping screw 11, the compression spring 10 and the sealing steel ball 9 are sequentially provided in the second screw hole 28. When the clamping screw 11 is installed in the second screw hole 28, the clamping screw 11 can compress the compression spring 10 backwards during the process of entering backwards, and the compression spring 10 synchronously squeezes the sealing steel ball 9 backwards, and the sealing steel ball 9 is subjected to The backward elastic force of the compression spring 10 enables the compression spring 10 to push the sealing steel ball 9 to close the first through hole 29, ensuring that the coal sample tube 12 is in a closed and pressure-maintaining state, and the gas in the coal sample tube 12 will not leak from the first through hole 29. A second through hole 30 is axially arranged in the tightening screw 11. When it is necessary to collect gas from the coal sample tube 12, the sealing steel ball 9 is pushed forward by a push pin to release the closed state of the first through hole 29. The gas in the coal sample tube 12 can enter the second screw hole 28 along the second through hole 30 and be discharged after passing through the first through hole 29. The accurate measurement of the amount of gas desorbed from the coal sample in the coal sample tube 12 can be conveniently achieved without the aid of additional gas extraction tools. Compared with the prior art of directly opening the ball valve for gas extraction, the present application can more effectively reduce the probability of gas leakage.

[0025] The transmission mechanism capable of controlling the opening and closing of the sample storage component includes a propulsion rack tube 7 and a propulsion rack 13. The propulsion rack tube 7 is sleeved on the outside of the sample storage component. The rear end of the propulsion rack tube 7 presses against the front end of the propulsion sleeve 6, so that when the propulsion sleeve 6 moves forward, it can generate a forward thrust on the propulsion rack tube 7, thereby pushing the propulsion rack tube 7 to move forward along with the forward movement of the propulsion sleeve 6. The front end of the propulsion rack tube 7 is connected to the propulsion rack 13, so that the propulsion rack 13 can move forward along with the forward movement of the propulsion rack tube 7. The propulsion rack 13 is meshed with the gear 14, so that when the propulsion rack 13 moves, it can drive the gear 14 to rotate. At the same time, it is set that the ball valve core 19 is in a closed state when the propulsion rack 13 is meshed with the gear 14 in the initial state.

[0026] A sealing ring 31 is provided at the position where the outer side of the drill pipe joint 1 contacts the outer sleeve 2, a sealing ring 32 is provided at the inner side of the first piston 4 and a sealing ring 33 is provided at the outer side, a sealing ring 35 is provided at the inner side of the second piston 5 and a sealing ring 34 is provided at the outer side, a sealing ring 36 is provided at the outer side of the push sleeve 6, a sealing ring 37 is provided at the position where the outer side of the coal sample pipe base 8 contacts the coal sample pipe 12, a sealing ring 38 is provided at the position where the outer side of the ball valve body 18 contacts the coal sample pipe 12, and a sealing ring 15 is provided at the position where the ball valve body 18 contacts the ball valve gland 20. The appropriate sealing ring model is selected according to the actual working requirements, and the sealing ring 31 is provided at the position where the outer side of the drill pipe joint 1 contacts the outer sleeve 2 to improve the drill pipe The sealing effect between the outer side of the joint 1 and the outer sleeve 2 prevents high-pressure water from seeping out along the gap between the outer side of the drill pipe joint 1 and the outer sleeve 2 to affect the pushing effect of the high-pressure water on the first piston 4; by arranging sealing rings on the inner and outer sides of the first piston 4, the sealing effect between the inner side of the first piston 4 and the second shaft section 302 and the sealing effect between the outer side of the first piston 4 and the outer sleeve 2 is improved, and the high-pressure water is prevented from seeping into the front side of the first piston 4 along the gap between the first piston 4 and the second shaft section 302 and the outer sleeve 2, thereby reducing the forward thrust of the high-pressure water on the first piston 4; by arranging sealing rings on the inner and outer sides of the second piston 5, the inner side of the second piston 5 and the third shaft section 302 are improved. The sealing effect between the second piston 5 and the outer side of the second piston 5 and the propulsion sleeve 6 is improved by providing a sealing ring 36 on the outer side of the propulsion sleeve 6 to improve the sealing effect between the propulsion sleeve 6 and the outer sleeve 2, and the sealing effect between the outer side of the second piston 5 and the propulsion sleeve 6 is improved, so as to prevent the high-pressure water flow from penetrating into the area in front of the second piston 5 along the gap between the second piston 5 and the propulsion sleeve 6 and the third shaft section 303, thereby reducing the thrust of the high-pressure water flow to push the second piston 5 forward; by providing a sealing ring 36 on the outer side of the propulsion sleeve 6 to improve the sealing effect between the propulsion sleeve 6 and the outer sleeve 2, the high-pressure water flow is prevented from penetrating into the area in front of the propulsion sleeve 6 along the gap between the propulsion sleeve 6 and the outer sleeve 2, thereby reducing the pressure of the high-pressure water flow; by providing a sealing ring 37 on the outer side of the coal sample tube base 8 at a position in contact with the coal sample tube 12, the sealing effect between the propulsion sleeve 6 and the outer sleeve 2 is improved. The sealing effect between the ball valve body 18 and the coal sample tube 12 is improved to prevent the gas contained in the coal sample in the coal sample tube 12 from leaking along the gap between the coal sample tube base 8 and the coal sample tube 12, causing a safety accident or affecting the detection effect; a sealing ring 38 is provided at the position where the ball valve body 18 contacts the coal sample tube 12 to improve the sealing effect between the ball valve body 18 and the coal sample tube 12, preventing the gas contained in the coal sample in the coal sample tube 12 from leaking along the gap between the ball valve body 18 and the coal sample tube 12, causing a safety accident or affecting the detection effect; a sealing ring 15 is provided at the position where the ball valve body 18 contacts the ball valve cover 20 to improve the sealing performance between the ball valve body 18 and the ball valve cover 20.

[0027] The working process of the present invention is as follows:

[0028] The sampler is used for drilling coal samples. The rotation of the drill rod drives the sampler to feed and sample. During the coal sampling process, the ball valve is closed to prevent broken coal and rock chips in the borehole from entering the coal sample tube and thus affecting the quality of the coal sample. The high-pressure water flow drives the ball valve core 19 to open and close, thereby achieving the purpose of sealing the coal sample. When working, first assemble the various components of the sampler according to the above-mentioned connection relationship, and adjust the assembled sampler to the initial state, so that the first piston 4 is close to the front end face of the drill rod joint 1, the second piston 5 is close to the front end face of the first boss 21, the push sleeve 6 is close to the front end face of the first piston 4, and the push rack tube 7 is close to the front end face of the push sleeve 6, so that the front end of the push rack 13 is meshed with the gear 14, and the position of the ball valve core 19 is adjusted so that the ball valve core 19 connected to the gear 14 is in a closed position in the initial state, ensuring that the ball valve core 19 is in the initial state. Closed state; after completing the assembly of the sampler and adjusting the initial state, connect the drill pipe joint 1 of the sampler to the drill pipe of the drilling rig, use the drilling rig as the power source for the sampler, and then start the drilling rig. The drilling rig performs rotary feeding and pushes the drill pipe to move downward along the deep hole. The sampler connected to the drill pipe moves downward along the deep hole with the drill pipe and finally reaches the bottom of the deep hole, and then the drilling rig is suspended; after the sampler reaches the bottom of the deep hole, start the water injection pump located outside the deep hole, and the high-pressure water injection pump starts to supply high-pressure water flow. The high-pressure water injection pump is connected to the hollow area of ​​the drill pipe joint 1 through a pipeline. At this time, the high-pressure water flows into After entering the cavity in the hollow area inside the drill pipe joint 1, it flows along the first flow hole 23 inside the first shaft section 301 of the core shaft 3. The high-pressure water flow enters the area between the drill pipe joint 1 and the first piston 4 through the first flow hole 23. The high-pressure water flow applies a forward thrust to the rear end face of the first piston 4, so that the first piston 4 moves forward after being affected by the high-pressure water flow in the rear area. Since the propulsion sleeve 6 is closely attached to the first piston 4 in the initial state, the first piston 4 applies a forward thrust to the propulsion sleeve 6 during the process of moving forward. The propulsion sleeve 6 moves forward under the action of the first piston 4. At the same time, due to the propulsion rack The tube 7 is closely attached to the front end surface of the propulsion sleeve 6 backward, so the propulsion rack tube 7 is pushed forward by the propulsion sleeve 6, so that the propulsion rack tube 7 moves forward synchronously under the action of the propulsion sleeve 6. At this time, the propulsion rack 13 connected to the propulsion rack tube 7 also moves forward synchronously with the forward movement of the propulsion rack tube 7. Since the propulsion rack 13 and the gear 14 are meshed, the gear 14 is rotated by the propulsion rack 13. Since the ball valve core 19 is connected to the gear 14, it also rotates with the rotation of the gear 14, so that the ball valve core 19 gradually switches from the initial closed state to the open state; after time t 1 After that, the first piston 4 moves forward by a distance s 1, so that the gear 14 rotates 90 degrees under the action of the propulsion rack 13, and the ball valve core 19 switches from the closed state to the open state. At this time, the first piston 4 is blocked by the first boss 21 between the second shaft section 302 and the third shaft section 303 on the core shaft 3 and no longer moves forward. At this time, the ball valve core 19 continues to remain in the open state; then the high-pressure water injection pump is turned off, and the drilling rig is started again. The drilling rig performs rotary feeding and drives the sampler to rotate and feed through the drill rod, so that the drill bit on the sampler can break the coal seam through rotary feeding. The first piston 4 passes through the opening of the second flow hole 25 on the side of the second shaft section 302, and the water flows into the second flow hole 25 through the opening, and flows along the second flow hole 25 to the opening of the second flow hole 25 on the front side of the first boss 21. At this time, the water flows in contact with the rear side of the second piston 5 and generates a forward thrust on the second piston 5. The second piston 5 moves forward slowly under the action of the water flow. During this period, the ball valve core 19 remains in an open state. After the sampling is completed, the drilling rig is paused, and the high-pressure water injection pump is restarted to continue to inject high-pressure water flow. The high-pressure water flow passes through the drill pipe joint 1, the first flow hole 23, and the second flow hole 25 in turn and enters the area behind the second piston 5. The high-pressure water flow generates a forward thrust on the second piston 5. The second piston 5 moves forward under the action of the high-pressure water flow. When the second piston 5 moves forward, it finally contacts the front end of the propulsion sleeve 6. At this time, the propulsion sleeve 6 is acted on by the forward thrust of the second piston 5, and the propulsion sleeve 6 is pushed forward. The sleeve 6 moves forward with the forward movement of the second piston 5. When the sleeve 6 moves forward, it applies a forward thrust to the rack tube 7. The rack tube 7 moves forward under the forward thrust of the sleeve 6. The rack tube 7 moves forward. The rack 13 moves forward synchronously under the action of the rack tube 7. The gear 14 meshing with the rack 13 rotates under the action of the rack 13. The ball valve core 19 rotates synchronously under the action of the gear 14, so that the ball valve core 19 gradually switches from the open state to the closed state. After a time t 2 After that, the second piston 5 pushes the propulsion sleeve 6, the propulsion rack tube 7 and the propulsion rack 13 forward to move a distance s 2, the gear 14 rotates 90 degrees under the action of the propulsion rack 13, and the ball valve core 19 rotates synchronously with the rotation of the gear 14 and switches from an open state to a closed state, so that the coal sample is sealed in the coal sample tube 12; the high-pressure water injection pump is turned off and the high-pressure water flow is no longer injected, and then the sampler is taken out from the deep hole through the exit function of the drilling rig, and the taken out sampler is removed from the drill rod of the drilling rig, and then the drill bit, outer sleeve 2, drill rod joint 1 and core shaft 3 are removed in turn, and finally the sample storage component is removed as a whole. At this time, the coal sample stored in the sample storage component is sealed and stored in the coal sample tube 12. Before taking the coal sample out of the coal sample tube 12, it is necessary to extract the desorbed gas first. At this time, it is necessary to take out the measuring tube used to measure the gas. The ejector pin on the coal sample tube 12 is pushed in from the rear side of the first through hole 29, and then pushes the sealing steel ball 9 forward, and the sealing steel ball 9 moves forward and is compressed by the spring. At this time, the first through hole 29 is connected to the coal sample tube 12 through the second screw hole 28 and the second through hole 30, and the gas that has been desorbed from the coal sample in the coal sample tube 12 passes through the second through hole 30, the second screw hole 28 and the first through hole 29 in turn and enters the measuring tube, thereby realizing the detection of the amount of gas desorbed from the coal sample. After completing the gas extraction and measurement work, the coal sample tube 12 is opened and the coal sample in the coal sample tube 12 is placed in relevant experimental equipment for analysis and inspection, and the total gas content of the coal sample is determined in combination with the desorbed gas amount detected before, thereby realizing the determination of the gas content of the coal seam where the coal sample is located.

[0029] During the whole process mentioned above, the sealing steel ball 9 can always close the first through hole 29 between the first screw hole 27 and the second screw hole 28 under the action of the compression spring 10 and the clamping screw 11. After the sampling work is completed and the ball valve core 19 is closed and the sampler is withdrawn from the deep hole, the coal sample tube 12 is always in a closed and pressure-maintaining state, and the gas desorbed from the coal sample will not leak.

[0030] The distance s mentioned in the above implementation process 1 、s 2 and time t 1 ,t 2 It is optimized based on production requirements through ground tests and analysis and calculation of downhole water injection pressure. It needs to be adjusted according to actual conditions in actual production.

[0031] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, which should also be regarded as the scope of protection of the present invention.

Claims

1. A deep hole closed pressure-maintaining sampler for coal mines, comprising an outer tube assembly, a core shaft, a sample storage assembly and a drive assembly, wherein the outer tube assembly comprises a drill pipe joint, an outer sleeve and a drill bit with a hollow structure connected in sequence, one end of the drill pipe joint is used to connect with the drill pipe, and the outer side of the other end is sleeved with an outer sleeve, one end of the outer sleeve is connected to the drill pipe joint, and the other end of the outer sleeve is connected to the drill bit, the drill bit comprises an outer drill bit and an inner drill bit, the inner drill bit is arranged on the inner side of the outer drill bit, and the inner drill bit and the outer drill bit are both hollow structures, a core shaft and a sample storage assembly are arranged in the outer tube assembly, one end of the core shaft is connected to the drill pipe joint, and the other end is connected to the sample storage assembly, a drive assembly is arranged between the core shaft and the sample storage assembly and the outer sleeve, a channel for water to flow in and out is arranged in the core shaft, and the core shaft is divided into three parts: a first shaft section, a second shaft section and a third shaft section, characterized in that: A first boss is arranged between the second shaft section and the third shaft section, the first shaft section is connected to the drill pipe joint, the driving assembly comprises a first piston, a second piston, a propulsion sleeve and a transmission mechanism capable of controlling the opening and closing of the sample storage assembly, a first piston is arranged between the second shaft section and the outer sleeve, the first piston is an annular structure and is sleeved on the second shaft section, the inner side of the first piston is close to the side surface of the second shaft section, the outer side of the first piston is close to the inner side surface of the outer sleeve, the first piston sleeve can slide along the second shaft section, a propulsion sleeve is sleeved on the outer side of the core shaft, a cavity is formed between the propulsion sleeve and the core shaft, the outer side surface of the propulsion sleeve is close to the inner side surface of the outer sleeve, one end of the propulsion sleeve is against the first piston, and the other end protrudes toward the core shaft and against the transmission mechanism, a second piston is arranged between the third shaft section and the propulsion sleeve, the second piston is an annular structure and is sleeved on the third shaft section, the second piston can slide back and forth along the third shaft section, the inner side of the second piston is close to the third shaft section of the core shaft, and the outer side of the second piston is close to the inner side surface of the propulsion sleeve; A first flow hole is arranged inside the first shaft section and the second shaft section of the core shaft, a part of the first flow hole is located inside the first shaft section, and another part is located inside the second shaft section, an opening on the rear side of the first flow hole is located on the rear end face of the first shaft section, and an opening on the front side of the first flow hole is located on the side face of the second shaft section, so that the first flow hole can connect the area of ​​the internal cavity of the drill rod joint and the area between the drill rod joint and the first piston, a second flow hole is arranged inside the second shaft section of the core shaft, an opening of the second flow hole located in the second shaft section is arranged on the side face of the second shaft section, and the position of the opening satisfies that when the first piston moves forward to the first boss position, the opening is just located on the rear side of the first piston, and the opening on the front side of the second flow hole is located on the front end face of the first boss, so that when the first piston contacts the first boss, the second flow hole can connect the area between the drill rod joint and the first piston and the area between the second piston and the first boss; A second boss is disposed at the front end of the drill rod joint, and a gap exists between the second boss and the opening of the first flow hole located in the second shaft section; The sample storage assembly includes a coal sample tube base, a coal sample tube, a ball valve body, a ball valve core and a ball valve gland. The rear end of the coal sample tube base is connected to the third shaft section of the core shaft, the front end of the coal sample tube base is connected to the rear end of the coal sample tube, the front end of the coal sample tube is connected to the rear end of the ball valve body, the ball valve body is connected to the ball valve gland, the ball valve core is arranged between the ball valve body and the ball valve gland, a gear is arranged on the side of the ball valve core, the gear is connected to the rotating shaft of the ball valve core, so that when the gear rotates, the ball valve core can be driven to rotate synchronously, so that the ball valve core can complete the switching between the open and closed states under the action of the gear; A first screw hole and a second screw hole are respectively arranged at the rear and front ends of the coal sample tube base, the first screw hole is located at the rear end of the coal sample tube base, and the second screw hole is located at the front end of the coal sample tube base. A through hole is arranged inside the coal sample tube base, so that the first screw hole and the second screw hole are connected through the through hole, and a clamping screw is arranged in the second screw hole, and the external thread of the clamping screw matches the internal thread of the second screw hole, so that the clamping screw can be rotated into the second screw hole, and a clamping screw, a compression spring and a sealing steel ball are arranged in the second screw hole in sequence. When the clamping screw is installed in the second screw hole, the clamping screw can compress the compression spring backwards during the backward entry process, and the compression spring synchronously squeezes the sealing steel ball backwards. The sealing steel ball is subjected to the backward elastic force of the compression spring, so that the compression spring can push the sealing steel ball to close the first through hole, thereby ensuring that the coal sample tube is in a closed and pressure-maintaining state, and the gas in the coal sample tube will not leak from the first through hole. The second through hole is axially arranged in the clamping screw; The transmission mechanism capable of controlling the opening and closing of the sample storage assembly comprises a propulsion rack tube and a propulsion rack, wherein the propulsion rack tube is sleeved on the outside of the sample storage assembly, one end of the propulsion rack tube abuts against the propulsion sleeve, the propulsion rack tube is connected to the propulsion rack, and the propulsion rack is meshed with the gear; A sealing ring is arranged at the position where the outer side of the drill pipe joint contacts the outer casing, sealing rings are arranged on the inner and outer sides of the first piston, sealing rings are arranged on the inner and outer sides of the second piston, a sealing ring is arranged on the outer side of the thrust casing, a sealing ring is arranged at the position where the outer side of the coal sample tube base contacts the coal sample tube, a sealing ring is arranged at the position where the outer side of the ball valve body contacts the coal sample tube, and a sealing ring is arranged at the position where the ball valve body and the ball valve gland contact.

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