Self-suction abrasive jet core drilling tool and core drilling method thereof

Abstract

The invention relates to the technical field of abrasive water jet drilling, and discloses a self-suction abrasive jet rock core drilling tool and a rock core drilling method.The self-suction abrasive jet rock core drilling tool comprises a drill rod, a drill barrel, at least two spray head bases and at least two jet flow spray head assemblies, and the drill barrel is detachably installed on the drill rod and is driven by the drill rod to spin; at least two installation channels penetrating through the upper end face and the lower end face of the drilling cylinder are formed in the cylinder wall of the drilling cylinder, an installation cavity is formed in the lower end face of the drilling cylinder, a nozzle base used for installing a jet nozzle assembly is fixedly installed in the installation channels, and wedge-shaped channel steel used for collecting rock cores cut by the jet nozzle assembly is installed in the installation cavity. The jet flow spray head assembly comprises a first spray head and a guide shell, a mixing cavity between the guide shell and the first spray head is communicated with the drainage opening and sucks abrasive materials staying on the working face through the drainage opening, so that the loss of the abrasive materials can be reduced when the core drilling tool cuts rocks, and the problems that hydraulic coring equipment is large in abrasive material loss and high in grinding efficiency are solved. And the method cannot be applied to a large-section hard rock scene.

Description

Technical Field

[0001] This invention relates to the field of abrasive waterjet drilling technology, and in particular to a self-priming abrasive waterjet core drilling tool and its core drilling method. Background Technology

[0002] Drilling tools refer to the tools used in activities such as drilling and blasting. They mainly include drilling (well drilling) tools and metallurgical drilling tools. Depending on the needs of geological work or engineering, core ring drill bits are often used to extract cylindrical rock samples from the borehole. These samples are also important physical materials for humans to understand underground geology during geological exploration and engineering construction.

[0003] In the process of core drilling, rotary drilling rigs have a high success rate and efficiency when drilling on soil layers such as clay, silty clay and sand. They are widely used in various foundation constructions such as cast-in-place piles, continuous walls, and foundation reinforcement. However, when core drilling on hard rock, they are prone to problems such as slow drilling speed and low core drilling efficiency. In addition, due to the limitations of their rock breaking method, the cutting blades used for rock breaking on the drill bit cool down slowly, resulting in rapid wear and frequent replacement of the cutting blades.

[0004] Therefore, considering the disadvantages of mechanical devices, some scholars have considered using hydraulic operations for coring.

[0005] The patent application with application number CN202223602831.5 describes a portable hydraulic coring device that uses water pressure to cut the core, increasing the coring efficiency. However, since this design is mainly used for cutting and sampling small cross-section rock cores, and its equipment structure is complex and causes significant wear on abrasives, the drilling efficiency for large cross-section hard rock is slow. Furthermore, large cross-section hard rock often occurs in areas with poor transportation conditions, such as high mountains and valleys, low hills, and coastal areas. Therefore, existing hydraulic coring devices are difficult to apply to large cross-section hard rock scenarios. Summary of the Invention

[0006] The purpose of this invention is to provide a self-priming abrasive jet core drilling tool and its core drilling method, which solves the problem that existing hydraulic core drilling equipment suffers from high abrasive wear and cannot be applied to large-section hard rock scenarios.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] In a first aspect, the present invention discloses a self-priming abrasive jet core extraction drill, comprising a drill rod, a drill barrel, at least two nozzle seats, at least two jet nozzle assemblies, and a core clamping and twisting assembly.

[0009] The lower end face of the drill rod is detachably connected to the upper end face of the drill cylinder, and the drill cylinder can rotate along the axis of the drill rod under the drive of the drill rod. The lower end face of the drill cylinder has an installation cavity, and the cylinder wall of the drill cylinder has at least two installation channels that penetrate its upper and lower end faces.

[0010] The core-embedded twisting assembly includes at least two wedge-shaped channel steels, all of which are installed in the mounting cavity, and the lower end faces of the wedge-shaped channel steels are all located in the same horizontal plane. The core collection area enclosed by the wedge-shaped channel steels is connected to the top wall of the mounting cavity of the drill barrel.

[0011] The jet nozzle assembly includes a first nozzle and a guide housing. Both the first nozzle and the guide housing are mounted on the nozzle seat, and the first nozzle is located inside the guide housing. The lower end face of the guide housing has a clearance opening for the first nozzle to cut the rock. The side wall of the guide housing has several drainage ports that penetrate its inner and outer walls. A mixing cavity is formed between the guide housing and the first nozzle, and the mixing cavity connects the drainage ports and the clearance openings. The nozzle orifice of the first nozzle points towards the working face.

[0012] The lower end face of the wedge-shaped channel steel is level with the nozzle hole of the first nozzle, and the core collection area enclosed by the wedge-shaped channel steel coincides with the core cutting area enclosed by the first nozzle.

[0013] As an optional solution, the inclined surface of the wedge-shaped channel steel forms an angle β with the working surface, where 0° < β < 90°.

[0014] As an optional solution, a gap is left between the top surface of the wedge-shaped channel steel and the top wall of the mounting cavity of the drill barrel.

[0015] As an optional solution, the guide housing is a second nozzle, and the nozzle orifice of the second nozzle is coaxial with the nozzle orifice of the first nozzle.

[0016] As an optional solution, the number of nozzle holes in the second nozzle is n1. In the formula, D0 is the outer diameter of the nozzle body of the second nozzle, l1 is the exposed length of the second nozzle on the nozzle body of the second nozzle, l2 is the target distance from the nozzle end of the second nozzle to the rock surface, and θ is the jet diffusion angle of the nozzle of the second nozzle.

[0017] As an optional configuration, the spacing between adjacent nozzle holes on a single plane of the second nozzle is l3. In the formula, D0 is the outer diameter of the nozzle body of the second nozzle, and n2 is the number of nozzle holes of the second nozzle on a single plane.

[0018] As an optional solution, the nozzle seat is threadedly connected to the first nozzle and the second nozzle.

[0019] Secondly, the present invention also discloses a core drilling method using a self-priming abrasive jet core drilling tool, employing the self-priming abrasive jet core drilling tool as described in claims 1-7, wherein the drilling method includes:

[0020] S1, the feeding device introduces a low-speed flowing abrasive water jet into the first nozzle until it flows into the working surface;

[0021] S2, the abrasive supply to the first nozzle is stopped, and a high-speed water flow is injected into the first nozzle by the feeding device. At this time, a negative pressure phenomenon occurs in the mixing chamber formed between the first nozzle and the guide housing.

[0022] S3, start the drill rod, the drill rod drives the drill barrel to rotate, cut and tunnel, and the core clamping and twisting assembly collects the sample cut by the first nozzle during the descent of the drill barrel.

[0023] The present invention has the following unexpected beneficial effects:

[0024] 1. The arrangement of the first nozzle and the guide shell in this invention ensures the cutting efficiency of the entire core drilling tool. The mixing cavity formed between the first nozzle and the guide shell is connected to several drainage ports and clearance ports on the guide shell. At least two wedge-shaped channel steels for collecting cores are also provided inside the drill barrel, and the core collection area surrounded by several wedge-shaped channel steels overlaps with the core cutting area surrounded by several first nozzles. This allows the abrasive ejected from the first nozzle to return to the mixing cavity through the drainage ports under negative pressure, realizing the reuse of abrasives. The wedge-shaped channel steels maximize the collection of rock cut by the first nozzle on the working surface, thereby solving the problem of high abrasive loss in existing hydraulic core drilling equipment, which cannot be applied to large-section hard rock scenarios.

[0025] 2. The present invention uses a second nozzle with the nozzle orifice at a certain angle to the first nozzle. The second nozzle can not only cooperate with the first nozzle to form a negative pressure effect, but also realize jet cross to form a three-dimensional cutting of the rock on the working surface. Compared with traditional hydraulic coring equipment, the technical solution described in the present invention has higher cutting efficiency.

[0026] 3. The nozzle hole layout on the second nozzle used in this invention is more scientific. A set of theoretical formulas for the number of nozzle holes and their spacing has been summarized based on experience, avoiding the structural waste problem when designing the second nozzle.

[0027] 4. The wedge-shaped channel steel used in this invention has an inclined surface that clamps the rock core at a certain angle to the working surface of the drill bit. As it rotates downward with the drill rod and drill barrel, it can generate a progressive torsional force, which greatly improves the integrity of the rock core obtained by the core drilling tool. Attached Figure Description

[0028] Figure 1 This is an overall schematic diagram of the self-priming abrasive jet core drilling tool according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the jet nozzle assembly of the self-priming abrasive jet core drilling tool according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the first nozzle of the self-priming abrasive jet core drilling tool according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the second nozzle of the self-priming abrasive jet core drilling tool according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the wedge-shaped channel steel part of the self-priming abrasive jet core drilling tool according to an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the drill barrel of the self-priming abrasive jet core drilling tool according to an embodiment of the present invention;

[0034] In the diagram, 1 is the drill pipe; 2 is the drill barrel; 201 is the installation channel; 202 is the installation cavity; 3 is the nozzle seat; 4 is the jet nozzle assembly; 401 is the first nozzle; 4011 is the first cylindrical section; 4012 is the conical transition section; 4013 is the second cylindrical section; 402 is the second nozzle; 4021 is the receiving section; 4022 is the third cylindrical section; 4023 is the conical diffusion section; 403 is the drain port; 404 is the mixing cavity; 5 is the core embedding torsion assembly; and 501 is the wedge-shaped channel steel. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0036] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] In the description of this invention, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] In one embodiment, such as Figures 1 to 6 As shown, the present invention provides a self-priming abrasive jet core drilling tool, characterized in that it includes a drill rod 1, a drill barrel 2, at least two nozzle seats 3, at least two jet nozzle assemblies 4, and a core clamping and twisting assembly 5.

[0039] The lower end face of the drill rod 1 is detachably connected to the upper end face of the drill barrel 2, and the drill barrel 2 can rotate along the axis of the drill rod 1 under the drive of the drill rod 1. The drill barrel 2 is coaxial with the drill rod 1, and the drill barrel 2 rotates synchronously with the drill rod 1. The rotation of the drill rod 1 is provided by the drilling equipment assumed to be on the bottom surface.

[0040] The lower end face of the drill barrel 2 has an installation cavity 202, and the cylinder wall of the drill barrel 2 has at least two installation channels 201 that penetrate its upper and lower end faces. The installation channels 201 are vertical channels, and the space of the installation channels 201 is sufficient to accommodate the first feeding pipe of the feeding device to pass through and be installed therein.

[0041] The core-embedded twisted component 5 includes at least two wedge-shaped channel steels 501, which are all installed in the mounting cavity 202. The lower end faces of the wedge-shaped channel steels 501 are all located in the same horizontal plane. The core collection area enclosed by the wedge-shaped channel steels 501 is connected to the top wall of the mounting cavity 202 of the drill barrel 2.

[0042] The spacing between the wedge-shaped channel steels 501 is not further defined here. The upper end faces of adjacent wedge-shaped channel steels 501 do not contact each other, and the shape formed by the upper end faces of at least two wedge-shaped channel steels 501 is circular.

[0043] The jet nozzle assembly 4 includes a first nozzle 401 and a guide housing. Both the first nozzle 401 and the guide housing are mounted on the nozzle seat 3, and the first nozzle 401 is located inside the guide housing. The lower end face of the guide housing has an clearance opening for the first nozzle 401 to cut the rock, and the size of the clearance opening is the same as the size of the nozzle hole of the first nozzle 401. Therefore, the clearance opening will not affect the cutting effect of the first nozzle 401.

[0044] The guide housing has several inlet ports 403 penetrating its inner and outer walls on its side wall. A mixing chamber 404 is formed between the guide housing and the first nozzle 401. When the first nozzle 401 cuts the working surface, the jet it ejects is under high pressure and high speed, so there is very little jet leakage. In this process, the high-speed jet also carries the air in the mixing chamber 404 along with it. Since the only interfaces connecting the mixing chamber 404 to the outside are the clearance port and the inlet ports 403, the air pressure in the mixing chamber 404 begins to decrease, causing the inlet ports 403 to begin to siphon outside air. At this time, the abrasive is in a low-speed state after colliding with the rock on the working surface, so it is very easy to be re-inhaled by the inlet ports 403. This allows the jet nozzle assembly 44 to reuse the abrasive for secondary operations, thereby reducing the wear of the abrasive when the core drilling tool uses water to cut the rock.

[0045] The nozzle hole of the first nozzle 401 points to the working surface. The feed end of the first nozzle 401 is connected to the supply end of the feeding device. The supply end of the feeding device is connected to the first nozzle 401 through the first feeding pipe. After the first feeding pipe is connected to the supply end of the feeding device, it passes through the installation channel 201 and the nozzle seat 3 in sequence and is connected to the first nozzle 401.

[0046] The lower end face of the wedge-shaped channel steel 501 is level with the height of the nozzle hole of the first nozzle 401. The rock core collection area enclosed by at least two wedge-shaped channel steels 501 coincides with the rock core cutting area enclosed by at least two first nozzles 401. The central area enclosed by several wedge-shaped channel steels 501 is the storage area for the rock core. When the drill barrel 2 is drilling, the wedge-shaped channel steel 501 itself has a certain material strength and can break the small rocks on its edge path. During the descent of the drill barrel 2, the wedge-shaped channel steel 501 collects the rocks cut by the first nozzles 401 in the central area and gradually compacts them, thereby achieving the grasping of the rock core.

[0047] Based on this, when the drill barrel 2 rotates under the drive of the drill rod 1, the jet nozzle assembly 4 installed on the nozzle seat 3 in its installation channel 201 cuts the rock on the working surface through the first nozzle 401. At this time, the mixing chamber 404 between the guide shell and the first nozzle 401 is agitated by the jet, and the outside air is siphoned through the drain port 403. During the siphoning process, the abrasive that remains on the working surface is also sucked in, so that a part of the abrasive can be reused by the first nozzle 401, reducing the consumption of abrasive when the core drilling tool cuts the rock. The cut rock is finally collected by the wedge-shaped channel steel 501, thus solving the problem that the existing hydraulic core drilling equipment has high abrasive consumption and cannot be applied to large cross-section hard rock scenarios.

[0048] Furthermore, such as Figures 1 to 6As shown, the inclined surface of the wedge-shaped channel steel 501 forms an angle β with the working surface, where 0° < β < 90°. Due to the presence of this inclined surface, small pieces of rock that are broken at the edge will be squeezed into the central area of ​​several wedge-shaped channel steels 501 when the wedge-shaped channel steel 501 follows the drill barrel 2 for drilling. They will gradually be compacted together with the rock that was originally located in the central area surrounded by several wedge-shaped channel steels 501, thereby making the obtained rock core more complete.

[0049] Furthermore, such as Figures 1 to 6 As shown, the wedge-shaped channel steel 501 is continuously subjected to the upward reaction force of the rock on the working surface during the drilling process following the drill barrel 2. In order to avoid the reaction force from damaging the drill barrel 2, which has many mechanical parts, a gap is left between the top surface of the wedge-shaped channel steel 501 and the top wall of the mounting cavity 202 of the drill barrel 2. From the perspective of structural design, this disperses the obstruction pressure on each component during operation, thereby increasing the reliability of the equipment.

[0050] Furthermore, such as Figures 1 to 6 As shown, the guide housing is a second nozzle 402. The feed end of the second nozzle 402 is connected to the supply end of the feeding device through a second feeding pipe. The installation path of the second feeding pipe is the same as that of the first feeding pipe. The nozzle hole of the second nozzle 402 is coaxial with the nozzle hole of the first nozzle 401. The jet of the second nozzle 402 advances along the outer wall of the first nozzle 401 to the nozzle hole position of the second nozzle and is ejected. Since the direction and ejection position of the jet of the second nozzle 402 are the same as those of the jet of the first nozzle 401, and the jet of the second nozzle 402 flows in the mixing chamber 404, the jet of the second nozzle 402 can accelerate the air flow in the mixing chamber 404, thereby enhancing the negative pressure effect in the mixing chamber 404. This allows the jet ejected by the second nozzle 402 to not only increase the cutting effect on the rock surface, but also to assist the mixing chamber 404 in sucking up more abrasive per unit time.

[0051] Both the first nozzle 401 and the second nozzle 402 are cylindrical. The inner hole of the first nozzle 401 is composed of a first cylindrical section 4011, a conical transition section 4012, and a second cylindrical section 4013. The inner diameter of the first cylindrical section 4011 is the same as that of the mounting channel 201, and the inner diameter of the second cylindrical section 4013 is smaller than that of the first cylindrical section 4011. The conical transition section 4012 is used to connect the first cylindrical section 4011 and the second cylindrical section 4013. The inner hole of the second nozzle 402 is composed of a receiving section 4021, a third cylindrical section 4022, and a conical diffuser section 4023. The receiving section 4021 is used to form a mixing chamber 404 together with the nozzle seat 3, and its side wall is provided with a drain port 403 communicating with the mixing chamber 404.

[0052] Furthermore, such as Figures 1 to 6 As shown, the number of nozzle holes in the second nozzle 402 is n1, n1 = In the formula, D0 is the outer diameter of the nozzle body of the second nozzle 402, l1 is the exposed length of the second nozzle 402 on the nozzle body, l2 is the target distance from the nozzle tip of the second nozzle 402 to the rock surface, and θ is the jet diffusion angle of the nozzle of the second nozzle 402. The number of nozzle holes of the second nozzle 402 set by the formula is more scientific, making the nozzle hole layout of the second nozzle 402 more reasonable and effectively controlling costs.

[0053] Furthermore, such as Figures 1 to 6 As shown, the spacing between adjacent nozzle holes on a single plane of the second nozzle 402 is l3. In the formula, D0 is the outer diameter of the nozzle body of the second nozzle 402, and n2 is the number of nozzle holes of the second nozzle 402 on a single plane. The formula solves the problem of unreasonable nozzle hole spacing on the second nozzle 402, which leads to reduced structural strength or insufficient cutting efficiency of the second nozzle 402.

[0054] Furthermore, such as Figures 1 to 6 As shown, the nozzle seat 3 is threadedly connected to the first nozzle 401 and the second nozzle 402. The center of the end face of the nozzle seat 3 away from the working surface has a cavity for accommodating the first nozzle 401, and the sidewall of this cavity has an internal thread for threaded connection to the first nozzle 401. The outer edge of the end face of the nozzle seat 3 away from the working surface has an external thread for threaded connection to the second nozzle 402. The distance between the internal and external threads ensures sufficient space between the first nozzle 401 and the second nozzle 402 to form a mixing cavity 404. The threaded arrangement of the nozzle seat 3 prevents vertical displacement of the first nozzle 401 and the second nozzle 402 during operation. This installation method facilitates disassembly, allowing for easy replacement of either the first nozzle 401 or the second nozzle 402 if damaged. This ensures the normal operation of the core drilling tool.

[0055] This invention also provides a core drilling method using a self-priming abrasive jet core drilling tool, employing the self-priming abrasive jet core drilling tool as described in claims 1-7, the drilling method comprising:

[0056] S1, the feeding device introduces a low-speed flowing abrasive water jet into the first nozzle 401 until it flows into the working surface;

[0057] S2, the abrasive supply to the first nozzle 401 is stopped, and a high-speed water flow is injected into the first nozzle 401 by the feeding device. At this time, a negative pressure phenomenon occurs in the mixing chamber 404 formed between the first nozzle 401 and the guide housing.

[0058] S3, start drill rod 1, the drill rod 1 drives the drill barrel 2 to rotate, cut and tunnel, and the core clamping torsion component 5 collects the sample cut by the first nozzle 401 during the descent of the drill barrel 2.

[0059] In this drilling method, considering the working principle of hydraulic cutting, the flow velocities of the low-speed and high-speed water streams ejected by the first nozzle 401 are not further limited. The specific flow velocities of the low-speed and high-speed water streams ejected by the first nozzle 401 are determined on-site based on the operating environment temperature of the first nozzle 401, the fluid medium used, the internal roughness of the first feed pipe, and the actual height of the first nozzle 401 above the working face.

[0060] In summary, the core drilling tool uses the first nozzle 401 to cut the working face, and the guide housing is installed outside the first nozzle 401 through the nozzle seat 3. At this time, a negative pressure effect is generated in the mixing chamber 404 between the guide housing and the first nozzle 401, which allows the core drilling tool to reuse the abrasive that remains on the working face after being ejected by the first nozzle 401. The setting of at least two wedge-shaped channel steels 501 enables the core drilling equipment to directly collect and compact the rock cut by the first nozzle 401 into a core, thereby solving the problem of high abrasive consumption in existing hydraulic coring equipment, which makes it unsuitable for large-section hard rock scenarios.

[0061] It should be understood that the terms "first," "second," etc., are used in this invention to describe various information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this invention, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information. In addition, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0062] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A self-priming abrasive jet core drilling tool, characterized in that: It includes a drill pipe (1), a drill barrel (2), at least two nozzle seats (3), at least two jet nozzle assemblies (4), and a core jamming and twisting assembly (5); The lower end face of the drill rod (1) is detachably connected to the upper end face of the drill cylinder (2), and the drill cylinder (2) can rotate along the axis of the drill rod (1) under the drive of the drill rod (1). The lower end face of the drill cylinder (2) has an installation cavity (202), and the cylinder wall of the drill cylinder (2) has at least two installation channels (201) that penetrate its upper and lower end faces. The core-embedded twisted component (5) includes at least two wedge-shaped channel steels (501), all of which are installed in the mounting cavity (202), and the lower end faces of the wedge-shaped channel steels (501) are all located in the same horizontal plane. The core collection area enclosed by the wedge-shaped channel steels (501) is connected to the top wall of the mounting cavity (202) of the drill barrel (2). The jet nozzle assembly (4) includes a first nozzle (401) and a guide housing. The first nozzle (401) and the guide housing are both mounted on the nozzle seat (3), and the first nozzle (401) is located inside the guide housing. The lower end face of the guide housing has a clearance opening for the first nozzle (401) to cut the rock. The side wall of the guide housing has several drainage ports (403) that penetrate its inner and outer walls. A mixing chamber (404) is formed between the guide housing and the first nozzle (401), and the mixing chamber (404) connects the drainage ports (403) and the clearance opening. The nozzle hole of the first nozzle (401) points towards the working face. The lower end face of the wedge-shaped channel steel (501) is level with the height of the nozzle hole of the first nozzle (401), and the core collection area enclosed by at least two wedge-shaped channel steels (501) coincides with the core cutting area enclosed by at least two first nozzles (401).

2. The self-priming abrasive jet core drilling tool according to claim 1, characterized in that: The inclined surface of the wedge-shaped channel steel (501) forms an angle β with the working surface, where 0° < β < 90°.

3. The self-priming abrasive jet core drilling tool according to claim 1, characterized in that: A gap is left between the top surface of the wedge-shaped channel steel (501) and the top wall of the mounting cavity (202) of the drill barrel (2).

4. The self-priming abrasive jet core drilling tool according to claim 1, characterized in that: The guide housing is a second nozzle (402), and the nozzle hole of the second nozzle (402) is coaxial with the nozzle hole of the first nozzle (401).

5. The self-priming abrasive jet core drilling tool according to claim 4, characterized in that: The second nozzle (402) has n1 nozzle holes. In the formula, D0 is the outer diameter of the nozzle body of the second nozzle (402), l1 is the exposed length of the second nozzle (402) on the nozzle body of the second nozzle (402), l2 is the target distance from the nozzle end of the second nozzle (402) to the rock surface, and θ is the jet diffusion angle of the nozzle of the second nozzle (402).

6. The self-priming abrasive jet core drilling tool according to claim 5, characterized in that: The spacing between adjacent nozzle holes on a single plane of the second nozzle (402) is l3. In the formula, D0 is the outer diameter of the nozzle body of the second nozzle (402), and n2 is the number of nozzle holes of the second nozzle (402) on a single plane.

7. The self-priming abrasive jet core drilling tool according to claim 4, characterized in that: The nozzle holder (3) is threadedly connected to the first nozzle (401) and the second nozzle (402).

8. A core drilling method using a self-priming abrasive jet core drill, characterized in that: The drilling method using the self-priming abrasive jet core drilling tool as described in claims 1-7 includes: S1, the feeding device introduces a low-speed flowing abrasive water jet into the first nozzle (401) until it flows into the working surface; S2, the abrasive supply to the first nozzle (401) is stopped, and a high-speed water flow is injected into the first nozzle (401) by the feeding device. At this time, a negative pressure phenomenon occurs in the mixing chamber (404) formed between the first nozzle (401) and the guide housing. S3, start the drill rod (1), the drill rod (1) drives the drill barrel (2) to rotate, cut and tunnel, and the core clamping twisted component (5) collects the sample cut by the first nozzle (401) during the descent of the drill barrel (2).

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