Magnetic-attraction type fast-rotation centrifugal slag removal and cavity forming device and control method therefor

Abstract

A magnetic-attraction type fast-rotation centrifugal slag removal and cavity forming device, comprising a device body (1) and magnetic-attraction cutter arms (2), wherein the device body (1) is of an integral structure, has a rear end provided with a female interface (1-1) and a front end provided with a male connector (1-13), is internally provided with a locking linkage slot (1-2) and a fluid passage (1-3) in sequence in an axial direction, and has side walls provided with cutter arm grooves (1-6) for placing the magnetic-attraction cutter arms (2); a locking linkage rod (1-5) and a locking spring (1-4) are mounted in the locking linkage slot (1-2), and the locking spring (1-4) has one end abutting against the bottom of the locking linkage slot (1-2) and the other end pushing the locking linkage rod (1-5) to move axially toward one end of the female interface (1-1); the locking linkage rod (1-5) has a middle provided with tapered teeth (1-5-b) and radial through holes (1-5-c) and is internally provided with an annular channel (1-5-d) in communication with the holes (1-5-c); one end of the magnetic-attraction cutter arm (2) is hinged in the tool arm groove (1-6), and a cutter arm gear (2-1) meshing with the tapered teeth (1-5-b) is provided at the end of the magnetic-attraction cutter arm (2) hinged to the cutter arm groove (1-6); and magnetic-attraction grooves (1-10) are provided at a portion of the device body (1) corresponding to the magnetic-attraction cutter arms (2), and an annular magnet (1-11) is fixed in the magnetic-attraction groove (1-10).

Description

Magnetic suction type fast vortex centrifugal slag removal and cavity creation device and its control method Technical Field

[0001] This invention belongs to the field of coal seam depressurization and permeability enhancement technology, and relates to a magnetic suction type fast rotation centrifugal slag removal and cavity creation device and its control method. Background Technology

[0002] With the coal mining depth in my country increasing at a rate of 10-25 meters per year, over 40% of mines now exceed 800 meters in depth. Deep mining faces challenges such as high ground stress (generally reaching 20-35 MPa) and low permeability (10... -4 ~10 -3 Facing technical challenges such as high mD levels and high gas pressure (2-5 MPa), the pressure relief range of traditional boreholes with diameters of 94-133 mm can only cover an area of ​​0.5-1.2 meters around the borehole, resulting in a small radius of influence and a long treatment cycle for gas disasters and rock bursts. Especially for hard coal seams with a firmness coefficient f≥1.5, the degree of development of primary fractures is reduced by 60%-80% compared to medium-hard coal seams, and the pressure relief and permeability enhancement effect of conventional ordinary boreholes is not obvious, which seriously restricts the safety and production efficiency of mines.

[0003] In existing technologies, hydraulic depressurization technologies mainly include two categories: hydraulic fracturing and hydraulic hydraulic drilling. Existing hydraulic fracturing devices use high-pressure water jets (35-50 MPa) to cut the coal seam and create slots. However, in hard coal seams with f≥2, the depth of a single fracturing operation is less than 0.3 m, and repeated drill rod advance and retreat operations increase working time by more than 40%. Existing hydraulic fracturing technology, while capable of producing fractures extending 5-15 m, shows that approximately 32% of cases experience fractures penetrating the roof and floor, inducing a risk coefficient of 0.18 for roof water inrush accidents. Furthermore, the random expansion of the fracture network results in an effective control rate of less than 65%, making it difficult to achieve directional permeability enhancement. Regarding mechanical borehole enlargement technology, current methods mainly employ cavity-forming devices driven by external power sources (such as compressed air, compressed water, or hydraulic pressure). A typical example is the hydraulically controlled reaming drill bit, which uses a hydraulic cylinder to extend the cutter arm. However, its hydraulic lines exhibit a 3-5 second response delay at depths exceeding 200m, making it difficult to open and close the cutter arm during drilling. This results in a cutter arm extension angle deviation of ±8°, which can easily lead to mechanical jamming in hard rock interbedded with gangue, and may also damage the drill bit due to premature cutter arm extension. Another type of pneumatic reaming device uses compressed air to drive the cutter arm. Although this solves the hydraulic delay problem, the failure rate of closure caused by coal slag clogging the air passage reaches 15%, and the proportion of coal particles larger than 30mm generated during reaming exceeds 40%, increasing the risk of slag removal system blockage by 35%.

[0004] It is evident that the existing technology has the following common defects: (1) Limitations in power control: The external hydraulic / pneumatic system is limited by the hole depth, and the control accuracy of the cutter arm opening and closing decreases exponentially with the increase of hole depth; (2) Coal slag interference problem: The cumulative amount of coal slag generated during the hole enlargement process can reach 0.8-1.2 m³. The existing device lacks an active slag removal structure design, which leads to coal slag accumulation causing mechanical lock-up, affecting the recovery of drill rod and hole-making device. Therefore, it is urgent to develop a controllable device to increase the borehole diameter in order to improve the pressure relief and permeability enhancement range of the borehole and enhance the prevention and control effect of coal and rock gas and rockburst disasters. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a magnetic suction type fast rotation centrifugal slag removal and cavity creation device and its control method, which can accurately control the opening of the cutter arm by the drill rod rotation speed, so as to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A magnetic suction type fast rotation centrifugal slag removal and cavity-making device includes a device body and a magnetic suction knife arm. The device body is an integral structure with a female interface at the rear end and a male connector at the front end. The internal part is provided with a locking linkage groove and a liquid-gas passage in sequence along the axial direction. The side wall is provided with a knife arm groove for placing the magnetic suction knife arm.

[0008] A locking linkage rod and a locking spring are installed in the locking linkage groove. One end of the locking spring abuts against the bottom of the locking linkage groove, and the other end pushes the locking linkage rod to move axially toward one end of the female interface.

[0009] The locking linkage rod has a tapered tooth and a radially penetrating linkage rod hole in the middle, and its interior has an annular channel communicating with the linkage rod hole.

[0010] One end of the magnetic suction knife arm is hinged to the knife arm groove, and the end of the magnetic suction knife arm that is hinged to the knife arm groove is provided with a knife arm gear that meshes with a conical tooth.

[0011] Magnetic grooves are provided at corresponding positions on the device body and the magnetic suction knife arm, and a ring magnet is fixed in the magnetic groove.

[0012] Furthermore, both ends of the locking linkage rod are provided with Glyd rings for sealing and sliding connection with the locking linkage groove.

[0013] Furthermore, the blade arm grooves are two in number and symmetrically distributed on both sides of the device body.

[0014] Furthermore, the magnetic suction groove is located at the end of the magnetic suction knife arm away from the hinge point of the magnetic suction knife arm, and the magnetic suction knife arm is closed and fixed to the device body through the annular magnet.

[0015] Furthermore, both the female and male connectors are equipped with filter baffles. The outer side of the filter baffles is axially fixed by elastic retaining rings, and the elastic retaining rings at the female connectors cooperate with the filter baffles to restrict the axial displacement of the locking linkage rod.

[0016] Furthermore, a channel hole is provided between the cutter arm groove and the liquid-air passage to guide high-pressure fluid from the liquid-air passage into the cutter arm groove for slag cleaning.

[0017] Furthermore, the magnetic suction knife arm is hinged to the knife arm groove by a fixing pin.

[0018] A control method for a magnetic suction type fast-rotating centrifugal slag removal and cavity-creating device includes:

[0019] The rotational speed of the device body causes the centrifugal force generated by the magnetic suction knife arm to be F. 离 The magnetic attraction force generated by the annular magnet of the device body and the annular magnet of the magnetic suction knife arm is F. 磁 The minimum thrust generated by the locking spring on the locking linkage rod is F. 弹 min Control F 离 <F 磁 +F 弹 min So that the magnetic suction knife arm is in a closed rotating state;

[0020] The rotational speed of the control device body causes F 离 >F 磁 +F 弹 max This causes the magnetic suction knife arm to unfold outward, and through the knife arm gear, it drives the locking linkage rod and locking spring to compress and move towards the male connector end, thereby putting the magnetic suction knife arm in the open rotation state;

[0021] The rotational speed of the control device body causes F 离 <F 磁 +F 弹 min The locking spring pushes the locking linkage rod to move toward the female interface (1-1) and drives the blade arm gear to rotate, thereby causing the magnetic suction blade arm to close and reset.

[0022] Furthermore, the magnetic suction-type fast-rotating centrifugal slag removal and cavity-creating device is installed on the drill rod via the female and male connectors, and the state of the magnetic suction cutter arm is controlled by the drill rod rotation speed.

[0023] The drilling speed should be ≤100r / min, and the hole-making speed should be ≥150r / min.

[0024] Furthermore, a channel hole is provided between the blade arm groove and the liquid-gas passage;

[0025] High-pressure fluid is introduced into the drill pipe. The high-pressure fluid flows sequentially through the female interface, annular channel, locking linkage groove, liquid-gas passage and male connector, and is ejected from the linkage rod hole and channel hole to clean the coal slag.

[0026] The beneficial effects of this invention are as follows:

[0027] This invention proposes a magnetic suction-type fast-rotation centrifugal slag removal and hole-making device. Its core lies in the innovative magnetic suction and fast-rotation centrifugal mechanism, which realizes precise control of the cutter arm and effective cleaning of coal slag, significantly improving the effect of borehole pressure relief and permeability enhancement.

[0028] The innovation of this technical solution is mainly reflected in three aspects. First, the device body adopts an integrated structure, which enhances structural strength and ensures the stability of the device in the complex environment of deep mines. Second, the ingenious design of the magnetic attraction and locking structure ensures that the cutter arm remains in a closed state during drilling, improving operational safety. Most importantly, a rapid-rotation centrifugal cutter arm opening method has been invented, which eliminates the need for external force and allows for rapid opening of the cutter arm simply by adjusting the drill rod speed, greatly improving operational efficiency.

[0029] The practicality of this technical solution is also significant. On the one hand, the device, through its built-in channel holes and linkage rod holes combined with high-pressure fluid, achieves real-time cleaning of coal slag during the cavity-making process, effectively preventing coal slag blockage from affecting the opening and closing of the cutter arm and ensuring the continuous and stable operation of the device. On the other hand, this device simplifies the structure of traditional hydraulic or water-driven cavity-making devices, reduces manufacturing costs and maintenance difficulty, while improving the reliability and durability of the device. Therefore, this invention has high field application value and is of great significance for improving the safety and efficiency of coal mining.

[0030] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0032] Figure 1 is a schematic diagram of a magnetic suction type fast rotation centrifugal slag removal and cavity-creating device in the embodiment;

[0033] Figure 2 is a schematic diagram of the locking linkage rod in the embodiment;

[0034] Figure 3 is a schematic diagram of the unfolded magnetic fast-rotating centrifugal slag removal and cavity-creating device in the embodiment.

[0035] Reference numerals: 1-device body, 2-magnetic blade arm, 3-cover plate, 1-1-female interface, 1-2-locking linkage groove, 1-3-liquid-gas passage, 1-4-locking spring, 1-5-locking linkage rod, 1-5-a-Glyd ring for hole, 1-5-b-conical tooth, 1-5-c-linkage rod hole, 1-5-d-annular channel, 1-6-blade arm groove, 1-7-gear groove, 1-8-fixing pin, 1-9-channel hole, 1-10-magnetic groove, 1-11-ring magnet, 1-12-rivet, 1-13-male connector, 1-14-filter baffle, 1-15-elastic retaining ring, 2-1-blade arm gear, 2-2-blade arm hole. Embodiments of the present invention

[0036] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0037] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0038] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0039] Please refer to Figures 1 to 3, which show a magnetic suction type fast-rotating centrifugal slag removal and cavity-making device. The magnetic suction knife arm opens the cavity rapidly with the drill rod inside the coal seam borehole, increasing the borehole diameter. At the same time, it can also realize the function of cleaning coal slag, preventing coal slag from entering the cavity-making structure, affecting the closure of the magnetic suction knife arm, and causing wear of the cavity-making device.

[0040] The device includes a device body 1 and a magnetic suction knife arm 2. The device body 1 is a hollow rod with an integrated structure. A female interface 1-1 is provided at the rear end, and a male connector 1-13 is provided at the front end. A locking linkage groove 1-2 and a liquid-gas passage 1-3 are arranged sequentially along the axial direction inside. A knife arm groove 1-6 is provided on the side wall, and the knife arm groove 1-6 is connected to the locking linkage groove 1-2.

[0041] Locking linkage rod 1-5 and locking spring 1-4 are sequentially installed along the axial direction in the locking linkage groove 1-2. The end of the locking spring 1-4 away from the locking linkage rod 1-5 contacts the bottom of the locking linkage groove 1-2, so that the locking spring 1-4 generates a thrust on the locking linkage rod 1-5 away from the locking spring 1-4.

[0042] The locking linkage rod 1-5 has a Glyd ring 1-5-a at both ends to form a sealed sliding connection with the locking linkage groove 1-2. The locking linkage rod 1-5 has a tapered tooth 1-5-b arranged axially and a plurality of linkage rod holes 1-5-c that penetrate the locking linkage rod 1-5 radially. The locking linkage rod 1-5 has an annular channel 1-5-d arranged axially and communicates with the linkage rod holes 1-5-c.

[0043] Specifically, there are 4 conical teeth 1-5-b, and 9 linkage rod holes 1-5-c are located at the top of the conical teeth 1-5-b and in the middle of adjacent conical teeth 1-5-b. The diameter of the linkage rod holes is 2mm. Each end of the locking linkage rod 1-5 has two grooves, and correspondingly, a glypto ring 1-5-a is installed.

[0044] Two blade arm slots 1-6 are symmetrically arranged on the device body 1. One end of the magnetic blade arm 2 is provided with a blade arm hole 2-2, and is hinged to the blade arm slot 1-6 through a fixing pin 1-8 passing through the blade arm hole 2-2. The end of the magnetic blade arm 2 that is hinged to the blade arm slot 1-6 is provided with a blade arm gear 2-1 that meshes with a bevel gear 1-5-b, so that when the magnetic blade arm 2 is rotated and unfolded, the locking linkage rod 1-5 is driven to move axially through the blade arm gear 2-1. Specifically, the device body 1 is provided with a gear slot 1-7 for accommodating the blade arm gear 2-1, and the gear slot 1-7 is connected to the blade arm slot 1-6 so that the blade arm gear 2-1 can be arranged at one end of the magnetic blade arm 2.

[0045] Magnetic grooves 1-10 are provided at corresponding positions on both the device body 1 and the magnetic blade arm 2. Annular magnets 1-11, fixed by rivets 1-12, are arranged within the magnetic blade arm 1-10, allowing the magnetic blade arm 2 to be magnetically fixed to the device body 1 when no force is applied. Specifically, in this embodiment, the magnetic grooves 1-10 are arranged at the end of the magnetic blade arm 2 furthest from the fixing pins 1-8 to maximize the magnetic attraction force.

[0046] Furthermore, symmetrically distributed channel holes 1-9 are provided between the cutter arm groove 1-6 and the liquid-gas passage 1-3. The diameter of the channel holes 1-9 is 4mm, which are used for high-pressure fluid to flow from the liquid-gas passage 1-3 into the cutter arm groove 1-6 to remove coal slag.

[0047] Furthermore, filter baffles 1-14 are provided at both the female interface 1-1 and the male connector 1-13, and an elastic retaining ring 1-15 is provided on the side of the filter baffle 1-14 away from the device body 1 to fix the filter baffle 1-14 axially; and the axial displacement of the locking linkage rod 1-5 is limited by the elastic retaining ring 1-15 at the female connector 1-1 in conjunction with the filter baffle 1-14.

[0048] Furthermore, a cover plate 3 is provided on the device body 1 at the fixing pins 1-8 to prevent coal slag from entering the connection between the fixing pins 1-8 and the device body 1.

[0049] Specifically, please refer to Figure 1. The assembly sequence of this magnetic suction-type fast-rotating centrifugal slag removal and cavity-creating device is as follows:

[0050] First, the locking spring 1-4 and the locking linkage rod 1-5 are placed into the locking linkage groove 1-2 in sequence. Then, the filter baffle 1-14 and the elastic retaining ring 1-15 are installed at the front end of the female interface 1-1. The locking spring 1-4 and the locking linkage rod 1-5, together with the filter baffle 1-14 and the elastic retaining ring 1-15 at the front end of the female interface 1-1, constitute the locking linkage mechanism.

[0051] Then, the magnetic suction knife arm 2 is placed in the knife arm groove 1-6, and the knife arm gear 2-1 is matched and meshed with the bevel gear 1-5-b. Then, the magnetic suction knife arm 2 is hinged and installed in the knife arm groove 1-6 by passing the fixing pin 1-8 through the knife arm hole 2-2.

[0052] Then, ring magnets 1-11 are installed in the magnetic grooves 1-10 of the magnetic suction knife arm 2 and the knife arm groove 1-6 respectively, and fixed with rivets 1-12;

[0053] Finally, install the filter baffle 1-14 and the elastic retaining ring 1-15 in sequence at the front end of the male connector 1-13.

[0054] Please refer to Figure 3, which shows the working state of the magnetic suction-type fast rotary centrifugal slag removal and cavity-creating device. The control method of the magnetic suction-type fast rotary centrifugal slag removal and cavity-creating device is as follows:

[0055] The rotational speed of the device body 1 causes the centrifugal force generated by the magnetic suction knife arm 2 to be F. 离 The magnetic attraction force generated by the annular magnet of the device body 1 and the annular magnet of the magnetic suction knife arm is F. 磁 The minimum thrust generated by the locking spring 1-4 on the locking linkage rod 1-5 is F. 弹 min Control F 离 <F 磁 +F 弹 min So that the magnetic suction knife arm 2 is in a closed rotation state;

[0056] The rotational speed of the control device body 1 causes the centrifugal force F generated by the magnetic suction knife arm 2 to be controlled. 离 The magnetic attraction force F is greater than that of the ring magnet 1-11. 磁 With the maximum thrust F of locking springs 1-4 弹 max That is, F 离 >F 磁 +F 弹 max This causes the magnetic suction knife arm 2 to unfold outward, and through the knife arm gear 2-1, it drives the locking spring 1-4 and the locking linkage rod 1-5 to compress and move towards the male connector 1-13, ultimately causing the magnetic suction knife arm 2 to be in the open rotation state.

[0057] The rotational speed of the control device body 1 causes F 离 <F 磁 +F 弹 min The locking spring 1-4 pushes the locking linkage rod 1-5 to move toward the female interface 1-1, and drives the knife arm gear 2-1 to rotate, thereby causing the magnetic knife arm to close and reset, and to be fixedly connected to the device body through magnetic attraction.

[0058] Furthermore, the magnetic suction type fast rotation centrifugal slag removal and cavity-making device is installed on the drill rod through the female interface 1-1 and the male connector 1-13, and the state of the magnetic suction cutter arm 2 is controlled by the rotation speed of the drill rod.

[0059] During normal drilling operations, the drill rod rotation speed should be controlled to be ≤100 r / min, so that F 离 <F 磁 +F 弹 min This causes the magnetic suction arm 2 to be in a closed rotational state; when drilling is required, the drill rod rotation speed is controlled to be ≥150 r / min, so that F 离 >F磁 +F 弹 max This causes the magnetic suction knife arm 2 to expand outward and move forward to rotate and create a cavity.

[0060] Furthermore, during drilling, high-pressure air or water is introduced into the drill rod. The high-pressure air or water flows out through the female interface 1-1, the annular channel 1-5-d, the locking linkage groove 1-2, the liquid-gas passage 1-3, and the male connector 1-13, and then flows out through the linkage rod hole 1-5-c and the channel hole 1-9, respectively, to clean the coal slag at the cutter arm gear 2-1 and the cutter arm groove 1-6.

[0061] Example 2

[0062] The difference between this embodiment and Embodiment 1 is that the magnetic suction knife arm 2 can be set to 3 or 4. When there are 3 magnetic suction knife arms 2, the magnetic suction knife arms 2 are evenly arranged at intervals of 120° on the device body 1; when there are 4 magnetic suction knife arms 2, the magnetic suction knife arms 2 are evenly arranged at intervals of 90° on the device body 1 to ensure that the magnetic suction knife arms 2 are subjected to uniform force on the device body.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A magnetic suction type fast-rotating centrifugal slag removal and cavity-creating device, characterized in that: The device includes a device body (1) and a magnetic suction knife arm (2). The device body (1) is an integral structure with a female interface (1-1) at the rear end and a male connector (1-13) at the front end. The device body (1) is provided with a locking linkage groove (1-2) and a liquid-gas passage (1-3) in sequence along the axial direction. The side wall is provided with a knife arm groove (1-6) for placing the magnetic suction knife arm (2). The locking linkage groove (1-2) is equipped with a locking linkage rod (1-5) and a locking spring (1-4). One end of the locking spring (1-4) abuts against the bottom of the locking linkage groove (1-2), and the other end pushes the locking linkage rod (1-5) to move axially toward one end of the female interface (1-1). The locking linkage rod (1-5) has a tapered tooth (1-5-b) and a radially penetrating linkage rod hole (1-5-c) in the middle, and its interior has an annular channel (1-5-d) communicating with the linkage rod hole (1-5-c). One end of the magnetic suction knife arm (2) is hinged in the knife arm groove (1-6), and the end of the knife arm arm (2-6) that is hinged to the knife arm groove (1-6) is provided with a knife arm gear (2-1) that meshes with the bevel teeth (1-5-b). A magnetic groove (1-10) is provided at the corresponding position of the device body (1) and the magnetic suction knife arm (2), and a ring magnet (1-11) is fixed in the magnetic groove (1-10). Both ends of the locking linkage rod (1-5) are provided with a Glyd ring (1-5-a) for sealing and sliding connection with the locking linkage groove (1-2); Both the female interface (1-1) and the male connector (1-13) are provided with filter baffles (1-14). The outer side of the filter baffles (1-14) is axially fixed by elastic retaining rings (1-15), and the elastic retaining rings (1-15) at the female interface (1-1) cooperate with the filter baffles (1-14) to restrict the axial displacement of the locking linkage rod (1-5).

2. The apparatus according to claim 1, characterized in that: The blade arm grooves (1-6) are two in number and symmetrically distributed on both sides of the device body (1).

3. The apparatus according to claim 1, characterized in that: The magnetic suction groove (1-10) is located at one end of the magnetic suction knife arm (2) away from the hinge point of the magnetic suction knife arm (2), and the magnetic suction knife arm (2) and the device body (1) are closed and fixed by the annular magnet (1-11).

4. The apparatus according to claim 1, characterized in that: A channel hole (1-9) is provided between the cutter arm groove (1-6) and the liquid-gas passage (1-3) to guide high-pressure fluid from the liquid-gas passage (1-3) into the cutter arm groove (1-6) for coal slag cleaning.

5. The apparatus according to claim 1, characterized in that: The magnetic suction knife arm (2) is hinged to the knife arm groove (1-6) by a fixing pin (1-8).

6. A control method for a magnetic suction type fast-rotating centrifugal slag removal and cavity-creating device, characterized in that, The control method for controlling the magnetic suction type fast-rotating centrifugal slag removal and cavity-forming device according to any one of claims 1 to 5 includes: The rotational speed of the device body (1) causes the centrifugal force generated by the magnetic suction knife arm (2) to be F. 离 The magnetic attraction force generated by the annular magnet of the device body (1) and the annular magnet of the magnetic suction knife arm (2) is F. 磁 The minimum thrust generated by the locking spring (1-4) on the locking linkage rod (1-5) is F. 弹 min Control F 离 <F 磁 +F 弹 min So that the magnetic suction knife arm (2) is in a closed rotation state; The rotational speed of the control device body (1) causes F 离 >F 磁 +F 弹 max This causes the magnetic suction knife arm (2) to unfold outward, and through the knife arm gear (2-1), it drives the locking linkage rod (1-5) and the locking spring (1-4) to compress and move towards the male connector (1-13), thereby causing the magnetic suction knife arm (2) to be in the open rotation state; The rotational speed of the control device body (1) causes F 离 <F 磁 +F 弹 min The locking spring (1-4) pushes the locking linkage rod (1-5) to move toward the female interface (1-1) and drives the blade arm gear (2-1) to rotate, thereby causing the magnetic suction blade arm to close and reset.

7. The control method according to claim 6, characterized in that: The magnetic suction type fast-rotating centrifugal slag removal and cavity-making device is installed on the drill rod through the female interface (1-1) and male connector (1-13), and the state of the magnetic suction cutter arm (2) is controlled by the drill rod rotation speed: The drilling speed should be ≤100r / min, and the hole-making speed should be ≥150r / min.

8. The control method according to claim 7, characterized in that: A channel hole (1-9) is provided between the blade arm groove (1-6) and the liquid-gas passage (1-3). High-pressure fluid is introduced into the drill pipe. The high-pressure fluid flows sequentially through the female interface (1-1), the annular channel (1-5-d), the locking linkage groove (1-2), the liquid-gas passage (1-3), and the male connector (1-13), and is ejected from the linkage rod hole (1-5-c) and the channel hole (1-9) to clean the coal slag.

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