Raw coal specimen coring device and method

Abstract

The present invention discloses a raw coal specimen coring device and method, and relates to equipment for coal scientific research. The raw coal specimen coring device comprises a flexible wrapping clamping mechanism and a coring mechanism; the flexible clamping mechanism comprises a clamping table and a plurality of flexible clamping components; a clamping cavity for accommodating a raw coal block and a coring hole for connecting the clamping cavity with the outside are formed between the plurality of flexible clamping components; the plurality of flexible wrapping components each comprises a supporting shell and an oil bag arranged on one side of the supporting shell facing the clamping cavity; the raw coal block is placed in the clamping cavity, and hydraulic oil is introduced into the oil bag, so that the oil bag can expand and wrap around the outside of the raw coal block, so as to realize flexible clamping of the raw coal block; the coring mechanism can pass through the coring hole and extend into the clamping cavity to perform raw coal specimen coring operation. The present invention can prevent the occurrence of raw coal block bedding damage, and the raw coal specimen has high quality and high coring efficiency.

Description

Technical Field

[0001] The invention relates to equipment for coal scientific research, and in particular to a raw coal test piece coring device and method. Background Art

[0002] Coal resources are the pillar energy of my country, and the safe and efficient mining of coal is an important guarantee for the production and life of the people. With the increase of mining depth, the physical and mechanical properties of coal seams change, and the gas content and ground stress of coal seams increase, resulting in frequent dynamic disasters in coal mines. The study of coal reservoir mechanical parameters and seepage characteristics has guiding significance for underground gas extraction, safe and efficient mining, etc. There is a huge demand for raw coal specimens in the scientific research process, but raw coal is a soft rock with relatively developed pores and joints, and it is difficult to coring from raw coal blocks. Conventional mechanical drill coring devices, due to large vibration, cause great damage or even breakage of the specimen during coring. Water needs to be added to cool the drill bit during drilling, resulting in the specimen being immersed in water for a long time, and the success rate of coring is extremely low. In addition, the raw coal blocks are mostly irregular in shape, and the conventional coring mechanical clamping device cannot fix the raw coal blocks well. The raw coal blocks are prone to offset during coring, and the clamping force is too large, which will cause the raw coal blocks to break, and it is impossible to ensure the acquisition of standard cylindrical specimens.

[0003] CN102866050A discloses a method for preparing a specimen of an irregular and easily broken coal rock block. The method comprises the following steps: performing surface treatment on a coal rock block that is easily broken or has an irregular shape, coating the surface of the coal rock block with a universal GS waterproof material, the coating thickness of which does not exceed 2 mm, and leaving the material aside to dry; taking a box mold that is suitable for the size of the coal rock block, evenly applying a layer of mold release agent on the inner surface of the box mold, and placing the treated coal rock block into the box mold; injecting the prepared cement slurry into the box mold at one time, and tamping the inner wall of the box mold with a spatula, and then gently tapping the side wall of the box mold with a rubber hammer to fill the box mold densely; after forming, curing the material at standard room temperature for 7 to 8 days; after curing, using a core drilling rig to vertically drill downwards along the drilling line to obtain a columnar specimen, and then using a rock cutter to cut off the cement slurry solidification sections at both ends of the drilled columnar specimen, leaving only the coal rock block section, and then grinding the specimen flat to obtain the desired coal rock specimen. The invention uses concrete to wrap coal rock blocks to form a high-strength, regular-shaped whole, which is suitable for the production of rock mechanics specimens of irregular and easily broken coal rock bodies. The specimens processed by this process can guarantee the mechanical properties of the original coal rock blocks to the greatest extent, solving the technical problems that irregular blocks are difficult to clamp and broken coal rock bodies are easy to be damaged under the original processing method. Undoubtedly, the technical solution disclosed in the above patent document is a beneficial attempt in the relevant technical field, but the preparation time period of the invention is long, which is not conducive to the development of scientific research. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a raw coal specimen coring device and method, which can prevent the bedding damage of the raw coal block, and the quality of the raw coal specimen is high and the coring efficiency is high.

[0005] A raw coal specimen coring device in the present invention comprises a flexible wrapping clamping mechanism and a coring mechanism;

[0006] The flexible clamping mechanism includes a clamping platform and a plurality of flexible clamping components; a clamping cavity for accommodating the raw coal block and a core hole for connecting the clamping cavity with the outside are formed between the plurality of flexible clamping components; the plurality of flexible wrapping components each include a supporting shell and an oil bag arranged on a side of the supporting shell facing the clamping cavity; the raw coal block is placed in the clamping cavity, and hydraulic oil is introduced into the oil bag, so that the oil bag can be expanded and wrapped around the outside of the raw coal block, so as to realize flexible clamping of the raw coal block;

[0007] The coring mechanism can pass through the coring hole and extend into the clamping cavity to perform coring operations on the raw coal specimen.

[0008] Furthermore, the flexible clamping mechanism also includes a fixing assembly for hoisting the raw coal block on the lower side of the clamping platform; the core sampling hole is located on the lower side of the clamping cavity, and multiple flexible clamping assemblies are arranged around the circumference of the core sampling hole, and multiple flexible clamping assemblies are all arranged on the lower side of the flexible clamping mechanism.

[0009] Furthermore, the upper parts of the plurality of support shells are hinged to the support platform, and the rotation of the plurality of support shells can make the lower parts of the respective support shells move away from or closer to each other, thereby realizing opening and closing.

[0010] Furthermore, the flexible clamping mechanism also includes a plurality of hydraulic jacks arranged on the lower side of the supporting shell, the plurality of hydraulic jacks respectively correspond to the plurality of supporting shells one by one, and the plurality of hydraulic jacks are respectively used to provide support for the corresponding supporting shells.

[0011] Furthermore, the fixing assembly includes a heat shrink tube and / or an elastic band.

[0012] Furthermore, the coring assembly includes a coring sleeve, a water jet cutting mechanism and a driving mechanism, and the driving mechanism can drive the coring sleeve and the water jet cutting mechanism to pass through the coring hole and extend into the clamping cavity to perform coring operations on the raw coal specimen.

[0013] Furthermore, the water jet cutting mechanism includes a nozzle, a mounting part and a supporting connecting rod; the nozzle is located outside the coring sleeve, the liquid outlet of the nozzle faces upward, and the nozzle is fixedly connected to the mounting part; the mounting part is fixedly connected to the supporting connecting rod, and the supporting connecting rod is connected to the lower side of the coring sleeve in a manner that allows relative rotation.

[0014] Furthermore, the water jet cutting mechanism also includes a guide gear fixedly connected to the mounting member, the coring sleeve includes a gear bearing sleeved on the lower portion of the coring sleeve and a rotating shaft arranged at the bottom of the coring sleeve, the gear bearing is meshed with the guide gear, the supporting connecting rod is connected to the rotating shaft, and the gear bearing is colinear with the axis of the rotating shaft.

[0015] Furthermore, the water jet cutting mechanism includes a water tank, a high-pressure water pump, an overflow valve, a throttle valve and a pressure gauge; the high-pressure water pump can pump out the liquid in the water tank and spray it out after passing through the throttle valve and the nozzle in sequence; the flow channel between the throttle valve and the nozzle is connected to the pressure gauge; the flow channel between the water pump and the throttle valve is connected to the liquid inlet of the overflow valve, and the water tank is connected to the liquid outlet of the overflow valve.

[0016] A raw coal sample coring method in the present invention uses the raw coal sample coring device as described above, and comprises the following steps:

[0017] S1, fixing the raw coal block on the clamping table through a fixing component, and forming a flexible clamp for the raw coal block through a plurality of flexible wrapping components;

[0018] S2, aligning the coring sleeve with the coring hole, and driving the mounting member and the supporting connecting rod to rotate with the axis of the coring sleeve as the rotation axis through the driving mechanism, thereby driving the nozzle and the coring sleeve to rotate with the axis of the coring sleeve as the rotation axis;

[0019] S3, the driving mechanism drives the mounting part and the supporting connecting rod to move vertically upward, thereby driving the nozzle and the coring sleeve to move vertically upward. When the coring sleeve abuts against the raw coal block, the friction between the supporting connecting rod and the rotating shaft of the coring sleeve is less than the friction between the coring sleeve and the raw coal block, so the coring sleeve stops rotating, and the supporting connecting rod and the mounting part rotate relative to the coring sleeve, thereby realizing the nozzle rotating around the coring sleeve;

[0020] S4, the nozzle sprays a high-pressure water jet, and the nozzle rotates around the coring sleeve to achieve ring cutting of the raw coal block. After the raw coal block is ring cut, the driving mechanism continues to drive the mounting part and the supporting connecting rod to move vertically upward, thereby continuing to drive the nozzle and the coring sleeve to move vertically upward, and the coring sleeve can protect the ring cut raw coal block inside it;

[0021] S5. After the vertical upward displacement reaches a predetermined value, the high-pressure water pump is turned off, the driving mechanism withdraws from the coring sleeve, and the raw coal specimen is obtained in the coring sleeve.

[0022] The beneficial effects of the present invention are:

[0023] (1) The present invention can ensure the stability of the raw coal block and absorb the vibration of the raw coal block, thereby preventing the stratification of the raw coal block from being damaged and ensuring the quality of the raw coal specimen;

[0024] (2) The fixing assembly of the present invention can further ensure the stability of the raw coal block, prevent the raw coal block from shifting during the coring process, and ensure that the raw coal specimen obtained is a standard cylindrical shape. At the same time, the arrangement form in which the coring hole is located at the bottom makes the coring mechanism move from bottom to top during coring. The water used in the coring process will fall due to gravity, preventing the raw coal block from being immersed in water for a long time, thereby further ensuring the quality of the raw coal specimen;

[0025] (3) The present invention can achieve precise circular cutting of the raw coal block by rotating the nozzle around the coring sleeve and ejecting the high-pressure water jet from the nozzle, with high coring efficiency. In addition, by achieving synchronous feeding of the nozzle and the coring sleeve, the high-pressure water jet is kept within the optimal target distance range for cutting. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2 It is a schematic diagram of the structure of the guide gear, gear bearing, sleeve, rotating shaft and supporting connecting rod of the present invention.

[0029] The markings in the attached drawings are as follows: 1-hydraulic control cabinet, 2-servo motor, 3-hydraulic oil tank, 4-clamping table, 5-support shell, 6-hinge, 7-raw coal block, 8-heat shrink tube, 9-elastic belt, 10-oil bag, 11-oil inlet hole, 12-oil outlet hole, 13-coring hole, 14-hydraulic jack, 15-coring sleeve, 16-driving mechanism, 17-nozzle, 18-mounting part, 19-guide gear, 20-gear bearing, 21-support connecting rod, 22-high-pressure hose, 23-high-pressure water pump, 24-water tank, 25-overflow valve, 26-throttle valve, 27-pressure gauge, 28-connecting rod extension section. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0031] like Figure 1-Figure 2As shown, a raw coal specimen coring device in this embodiment includes a flexible wrapping clamping mechanism and a coring mechanism; the flexible clamping mechanism includes a clamping table 4 and a plurality of flexible clamping components; a clamping cavity for accommodating a raw coal block 7 and a coring hole 13 for connecting the clamping cavity with the outside are formed between the plurality of flexible clamping components; the plurality of flexible wrapping components each include a supporting shell 5 and an oil bladder 10 arranged on a side of the supporting shell 5 facing the clamping cavity; placing the raw coal block 7 in the clamping cavity, and introducing hydraulic oil into the oil bladder 10, can cause the oil bladder 10 to expand and wrap around the outside of the raw coal block 7, so as to achieve flexible clamping of the raw coal block 7; the coring mechanism can pass through the coring hole 13 and extend into the clamping cavity to perform raw coal specimen coring operations.

[0032] There are two flexible clamping components, and the two flexible clamping components are symmetrical to each other. A clamping cavity that can be opened and closed is formed between the two flexible clamping components. The clamping cavity is a rectangular parallelepiped and can accommodate the raw coal block 7. The oil bag 10 is located between the raw coal block 7 and the supporting shell 5. After the oil bag 10 is expanded, it can wrap around the outside of the raw coal block 7 to achieve all-round flexible clamping and fixation of the raw coal block 7. When the coring mechanism performs the coring operation on the raw coal block 7 for the raw coal specimen, it can ensure the stability of the raw coal block 7 and absorb the vibration of the raw coal block 7 to prevent the bedding damage of the raw coal block 7 and ensure the quality of the raw coal specimen.

[0033] In this embodiment, the flexible clamping mechanism also includes a fixing assembly for hoisting the raw coal block 7 on the lower side of the clamping platform 4; the coring hole 13 is located on the lower side of the clamping cavity, and a plurality of the flexible clamping assemblies are arranged around the circumference of the coring hole 13, and a plurality of the flexible clamping assemblies are arranged on the lower side of the flexible clamping mechanism. The fixing assembly can further ensure the stability of the raw coal block 7, prevent the raw coal block 7 from shifting during the coring process, and ensure that the obtained raw coal specimen is a standard cylindrical shape. At the same time, the arrangement form of the coring hole 13 located at the bottom makes the coring mechanism move from bottom to top during coring, and the water used in the coring process will fall due to gravity, preventing the raw coal block 7 from being immersed in water for a long time, further ensuring the quality of the raw coal specimen.

[0034] In this embodiment, the upper parts of the plurality of support shells 5 are hinged to the support platform, and the rotation of the plurality of support shells 5 can make the lower parts of the support shells 5 move away from or closer to each other, thereby realizing opening and closing. The outward rotation of the two support shells 5 can make the lower parts of the two support shells 5 move away from each other, and the lower part of the clamping cavity is open, which can facilitate the fixing of the raw coal block 7 on the lower side of the clamping platform 4; the inward rotation of the two support shells 5 can make the lower parts of the two support shells 5 move closer to each other, and the lower part of the clamping cavity is closed, and the support shells 5 can provide support for the oil bag 10. The support shell 5 and the support platform can be hinged by connecting the two with a hinge 6.

[0035] In this embodiment, the flexible clamping mechanism further includes a plurality of hydraulic jacks 14 disposed on the lower side of the support shell 5, and the plurality of hydraulic jacks 14 correspond to the plurality of support shells 5 one by one, and the plurality of hydraulic jacks 14 are respectively used to provide support for the corresponding support shells 5. The output shaft of the hydraulic jack 14 can be extended and retracted in the up-down direction, and before the two support shells 5 rotate outward, the output shaft of the hydraulic jack 14 shortens downward to make way for the flipping of the support shell 5, and after the two support shells 5 rotate outward, the output shaft of the hydraulic jack 14 extends upward and finally abuts against the support shell 5, providing support for the support shell 5 to prevent the support shell 5 from flipping.

[0036] In this embodiment, the fixing assembly includes a heat shrink tube 8 and / or an elastic band 9. Preferably, the heat shrink tube 8 and the elastic band 9 are used simultaneously, which can achieve a better positioning effect.

[0037] In this embodiment, the coring assembly includes a coring sleeve 15, a water jet cutting mechanism and a driving mechanism 16. The driving mechanism 16 can drive the coring sleeve 15 and the water jet cutting mechanism through the coring hole 13 and extend into the clamping cavity to perform the raw coal specimen coring operation. The driving mechanism 16 adopts an existing mechanical arm or mechanical rocker arm, which can drive the coring sleeve 15 and the water jet cutting mechanism to rotate and move in the up and down directions. The coring sleeve 15 is made of stainless steel and contains a graphene coating. The inner hole diameter of the coring sleeve 15 is φ50, and the inner hole length is greater than 100 mm. For example, the inner hole specification of the coring sleeve 15 is φ50*120 mm or φ50*125 mm, which can be used to obtain a standard cylindrical raw coal specimen of φ50*100 mm. The wall thickness of the coring sleeve 15 is less than 1 mm, which can be used to obtain a standard cylindrical raw coal specimen of φ50*100 mm. The size of the raw coal block 7 in the up and down direction is greater than 100 mm, and the diameter of the coring hole 13 is approximately 55 mm.

[0038] In this embodiment, the water jet cutting mechanism includes a nozzle 17, a mounting member 18 and a supporting connecting rod 21; the nozzle 17 is located outside the coring sleeve 15, the liquid outlet of the nozzle 17 faces upward, and the nozzle 17 is fixedly connected to the mounting member 18; the mounting member 18 is fixedly connected to the supporting connecting rod 21, and the supporting connecting rod 21 is connected to the lower side of the coring sleeve 15 in a relatively rotatable manner. Preferably, the nozzle 17 is attached to the outer wall of the coring sleeve 15, and the nozzle 17 rotates around the coring sleeve 15. The high-pressure water jet ejected by the nozzle 17 can achieve precise circumferential cutting of the raw coal block 7, and can provide a path for the upward movement of the coring sleeve 15, with high coring efficiency. After the high-pressure water jet does work, the water and coal debris with reduced initial velocity will fall due to gravity, preventing contamination of the raw coal specimen, and further ensuring the quality of the raw coal specimen.

[0039] In this embodiment, the water jet cutting mechanism further includes a guide gear 19 fixedly connected to the mounting member 18, the coring sleeve 15 includes a gear bearing 20 sleeved on the lower part of the coring sleeve 15 and a rotating shaft arranged at the bottom of the coring sleeve 15, the gear bearing 20 is meshed with the guide gear 19, the support connecting rod 21 is connected to the rotating shaft, and the gear bearing 20 is colinear with the axis of the rotating shaft. The mounting member 18 and the support connecting rod 21 are driven to move vertically upward by the driving mechanism 16, thereby driving the nozzle 17 and the coring sleeve 15 to move vertically upward. When the coring sleeve 15 abuts against the raw coal block 7, since the friction between the support connecting rod 21 and the rotating shaft of the coring sleeve 15 is less than the friction between the coring sleeve 15 and the raw coal block 7, the coring sleeve 15 stops rotating, and the support connecting rod 21 and the mounting member 18 rotate relative to the coring sleeve 15, thereby realizing the rotation of the nozzle 17 around the coring sleeve 15. Furthermore, since the gear bearing 20 can rotate, the gear bearing 20 meshes with the guide gear 19, and the two ends of the support link 21 are respectively connected to the rotating shaft and the guide gear 19, so that the distance between the axis of the guide gear 19 and the axis of the gear bearing 20 is a fixed value, so during the orbiting process of the nozzle 17, the guide gear 19 and the gear bearing 20 can ensure that the mounting member 18 and the nozzle 17 rotate around the coring sleeve 15. In order to ensure the supporting effect of the support link 21, a connecting rod extension section 28 connected to the support link 21 can also be provided.

[0040] In this embodiment, a hydraulic control cabinet 1, a servo motor 2 and a hydraulic oil tank 3 are also included. The hydraulic control cabinet 1 and the servo motor 2 can control the oil in and out of the hydraulic oil tank 3. The support shell 5 is provided with an oil inlet 11 and an oil outlet 12 of the oil bag 10, and the oil inlet 11 and the oil outlet 12 are both connected to the hydraulic oil tank 3. The hydraulic oil tank 3 can also provide hydraulic oil for the hydraulic jack 14 and the drive mechanism 16. The hydraulic control cabinet 1 drives the mechanism 16 to control the circular cutting speed and vertical feed, realize the synchronous feed of the nozzle 17 and the coring sleeve 15, and keep the high-pressure water jet cutting within the optimal target distance range.

[0041] In this embodiment, the water jet cutting mechanism includes a water tank 24, a high-pressure water pump 23, an overflow valve 25, a throttle valve 26 and a pressure gauge 27; the high-pressure water pump 23 can pump out the liquid in the water tank 24 and spray it out after passing through the throttle valve 26 and the nozzle 17 in sequence; the flow channel between the throttle valve 26 and the nozzle 17 is connected to the pressure gauge 27; the flow channel between the water pump and the throttle valve 26 is connected to the liquid inlet of the overflow valve 25, and the water tank 24 is connected to the liquid outlet of the overflow valve 25. The flow channel between the throttle valve 26 and the nozzle 17 adopts a high-pressure hose 22. The high-pressure water pump 23 can pump out the liquid in the water tank 24 and spray it out after passing through the throttle valve 26 and the nozzle 17 in sequence to form a high-pressure water jet.

[0042] A raw coal sample coring method in this embodiment uses the raw coal sample coring device as described above, and includes the following steps:

[0043] S1, fixing the raw coal block 7 on the clamping table 4 by means of a fixing component, and forming a flexible clamp for the raw coal block 7 by means of a plurality of flexible wrapping components;

[0044] Specifically, first, the output shaft of the hydraulic jack 14 is shortened downward to make way for the flipping of the support shell 5, and then the two support shells 5 are rotated outward to make the lower parts of the two support shells 5 move away from each other, the lower part of the clamping cavity is opened, and the raw coal block 7 wrapped by the heat shrink tube 8 is fixed to the clamping table 4 through the elastic band 9; then, the two support shells 5 are rotated inward to make the lower parts of the two support shells 5 approach each other, and the lower part of the clamping cavity is closed; then, the output shaft of the hydraulic jack 14 is extended upward and finally abutted against the support shell 5, providing support for the support shell 5 to prevent the support shell 5 from flipping, and the support shell 5 can provide support for the oil bag 10; finally, high-pressure hydraulic oil is introduced into the oil bag 10 to complete the all-round wrapping and fixing of the raw coal block 7, and the high pressure here can be 5KPa;

[0045] S2, align the coring sleeve 15 with the coring hole 13, and drive the mounting member 18 and the supporting connecting rod 21 to rotate with the axis of the coring sleeve 15 as the rotation axis through the driving mechanism 16, thereby driving the nozzle 17 and the coring sleeve 15 to rotate with the axis of the coring sleeve 15 as the rotation axis;

[0046] S3, the drive mechanism 16 drives the mounting member 18 and the supporting connecting rod 21 to move vertically upward, thereby driving the nozzle 17 and the coring sleeve 15 to move vertically upward. When the coring sleeve 15 abuts against the raw coal block 7, since the friction between the supporting connecting rod 21 and the rotating shaft of the coring sleeve 15 is less than the friction between the coring sleeve 15 and the raw coal block 7, the coring sleeve 15 stops rotating, and the supporting connecting rod 21 and the mounting member 18 rotate relative to the coring sleeve 15, thereby realizing the nozzle 17 rotating around the coring sleeve 15;

[0047] S4, the nozzle 17 sprays a high-pressure water jet, and the nozzle 17 rotates around the coring sleeve 15 to achieve ring cutting of the raw coal block 7. After the raw coal block 7 is ring cut, the driving mechanism 16 continues to drive the mounting member 18 and the supporting connecting rod 21 to move vertically upward, thereby continuing to drive the nozzle 17 and the coring sleeve 15 to move vertically upward, and the coring sleeve 15 can protect the ring cut raw coal block 7 inside it;

[0048] S5. After the vertical upward displacement reaches a predetermined value, the high-pressure water pump 23 is turned off, the driving mechanism 16 withdraws from the coring sleeve 15, and the raw coal specimen is obtained in the coring sleeve 15;

[0049] Specifically, the vertical upward displacement refers to the vertical upward displacement of the coring sleeve 15 after it abuts against the raw coal block 7. The predetermined value is 100 mm, and the obtained raw coal specimen is a standard cylindrical raw coal specimen of φ50*100 mm.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A raw coal specimen coring device, characterized in that: It includes a flexible wrapping clamping mechanism and a coring mechanism; The flexible clamping mechanism comprises a clamping platform (4) and a plurality of flexible clamping components; a clamping cavity for accommodating a raw coal block (7) and a core hole (13) for connecting the clamping cavity to the outside are formed between the plurality of flexible clamping components; the plurality of flexible wrapping components each comprise a supporting shell (5) and an oil bag (10) arranged on a side of the supporting shell (5) facing the clamping cavity; the raw coal block (7) is placed in the clamping cavity, and hydraulic oil is introduced into the oil bag (10), so that the oil bag (10) can expand and wrap around the outside of the raw coal block (7), thereby realizing flexible clamping of the raw coal block (7); The coring mechanism can pass through the coring hole (13) and extend into the clamping cavity to perform coring operations on the raw coal specimen; The flexible clamping mechanism further comprises a fixing assembly for hoisting the raw coal block (7) on the lower side of the clamping platform (4); the coring hole (13) is located on the lower side of the clamping cavity, a plurality of the flexible clamping assemblies are arranged around the coring hole (13), and the plurality of the flexible clamping assemblies are all arranged on the lower side of the flexible clamping mechanism; The coring assembly comprises a coring sleeve (15), a water jet cutting mechanism and a driving mechanism (16); the driving mechanism (16) is capable of driving the coring sleeve (15) and the water jet cutting mechanism to pass through the coring hole (13) and extend into the clamping cavity to perform a coring operation on the raw coal specimen; The water jet cutting mechanism comprises a nozzle (17), a mounting member (18) and a supporting connecting rod (21); the nozzle (17) is located outside the coring sleeve (15), the liquid outlet of the nozzle (17) faces upward, and the nozzle (17) is fixedly connected to the mounting member (18); the mounting member (18) is fixedly connected to the supporting connecting rod (21), and the supporting connecting rod (21) is connected to the lower side of the coring sleeve (15) in a relatively rotatable manner.

2. The raw coal specimen coring device according to claim 1, characterized in that: The upper parts of the plurality of support shells (5) are hinged to the support platform, and the rotation of the plurality of support shells (5) can cause the lower parts of the respective support shells (5) to move away from or closer to each other, thereby achieving opening and closing.

3. The raw coal specimen coring device according to claim 2, characterized in that: The flexible clamping mechanism further comprises a plurality of hydraulic jacks (14) arranged on the lower side of the support shell (5), the plurality of hydraulic jacks (14) respectively corresponding to the plurality of support shells (5) one by one, and the plurality of hydraulic jacks (14) are respectively used to provide support for the corresponding support shells (5).

4. The raw coal specimen coring device according to claim 1, characterized in that: The fixing assembly comprises a heat shrink tube (8) and / or an elastic band (9).

5. The raw coal specimen coring device according to claim 1, characterized in that: The water jet cutting mechanism further comprises a guide gear (19) fixedly connected to the mounting member (18); the coring sleeve (15) comprises a gear bearing (20) sleeved on the lower part of the coring sleeve (15) and a rotating shaft arranged at the bottom of the coring sleeve (15); the gear bearing (20) is meshed with the guide gear (19); the supporting connecting rod (21) is connected to the rotating shaft; and the gear bearing (20) is colinear with an axis of the rotating shaft.

6. The raw coal specimen coring device according to claim 5, characterized in that: The water jet cutting mechanism comprises a water tank (24), a high-pressure water pump (23), an overflow valve (25), a throttle valve (26) and a pressure gauge (27); the high-pressure water pump (23) can pump out the liquid in the water tank (24) and spray it out after passing through the throttle valve (26) and the nozzle (17) in sequence; the flow channel between the throttle valve (26) and the nozzle (17) is connected to the pressure gauge (27); the flow channel between the water pump and the throttle valve (26) is connected to the liquid inlet of the overflow valve (25), and the water tank (24) is connected to the liquid outlet of the overflow valve (25).

7. A method for coring a raw coal specimen, characterized in that: The raw coal specimen coring device as claimed in claim 6 is used, comprising the following steps: S1, fixing the raw coal block (7) on the clamping platform (4) by means of a fixing component, and forming a flexible clamping for the raw coal block (7) by means of a plurality of flexible wrapping components; S2, aligning the coring sleeve (15) with the coring hole (13), and driving the mounting member (18) and the supporting connecting rod (21) to rotate about the axis of the coring sleeve (15) as the rotation axis through the driving mechanism (16), thereby driving the nozzle (17) and the coring sleeve (15) to rotate about the axis of the coring sleeve (15) as the rotation axis; S3, the driving mechanism (16) drives the mounting member (18) and the supporting connecting rod (21) to move vertically upward, thereby driving the nozzle (17) and the coring sleeve (15) to move vertically upward. When the coring sleeve (15) abuts against the raw coal block (7), since the friction between the supporting connecting rod (21) and the rotating shaft of the coring sleeve (15) is smaller than the friction between the coring sleeve (15) and the raw coal block (7), the coring sleeve (15) stops rotating, and the supporting connecting rod (21) and the mounting member (18) rotate relative to the coring sleeve (15), thereby realizing the nozzle (17) rotating around the coring sleeve (15); S4, the nozzle (17) ejects a high-pressure water jet, and the nozzle (17) rotates around the coring sleeve (15) to achieve ring cutting of the raw coal block (7). After the raw coal block (7) is ring cut, the driving mechanism (16) continues to drive the mounting member (18) and the supporting connecting rod (21) to move vertically upward, thereby continuing to drive the nozzle (17) and the coring sleeve (15) to move vertically upward, and the coring sleeve (15) can protect the ring cut raw coal block (7) inside it; S5. After the vertical upward displacement reaches a predetermined value, the high-pressure water pump (23) is turned off, the driving mechanism (16) withdraws from the coring sleeve (15), and the raw coal specimen is obtained in the coring sleeve (15).

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