A soft coal seam layered cutting drilling method and drilling tool

Abstract

The present invention relates to the technical field of coal seam drilling, and in particular to a layered cutting drilling method and drilling tool for soft coal seams, comprising a first drill rod, a drill bit 1, a second drill rod and a drill bit 2, wherein the drill bit 2 is located between the first drill rod and the second drill rod, and the drill bit 2 is fixedly mounted on the side wall of the second drill rod. The side walls of the second drill rod and the drill bit 2 are respectively provided with a recovery chamber and a sliding hole, and the recovery chamber and the sliding hole are interconnected. The sliding blade drives the casing to perform intermittent drilling, so that the casing always follows the drill bit 2 for synchronous drilling. The thread 1 squeezes the debris between the outer side of the casing and the inner wall of the mining hole, so that the debris forms a thread shape and is evenly distributed on the outer side of the casing, thereby improving the anti-collapse strength of the mining hole. The second drill rod drives the rotating ring to rotate, so that the support rod and the stirring rod stir and loosen the debris between the second drill rod and the casing. The loosened debris reduces the vibration of the second drill rod on the casing, thereby improving the anti-collapse strength of the mining hole.

Description

Technical Field

[0001] The present invention relates to the technical field of coal seam drilling, in particular to a layered cutting and drilling method for soft coal seams and a drilling tool. Background Art

[0002] In the process of coal mining, due to the low strength, loose structure, cracks and poor stability of the soft coal seam, the mining hole is easy to break, resulting in the collapse and shrinkage of the drill hole, which affects the hole formation rate. In addition, it is impossible to install casing after mining, which affects gas extraction and brings great challenges to the drilling operation. For example, the soft coal seam gas extraction drilling and hole protection drill tool disclosed in Publication No.: CN106958418B, when in use, after the telescopic column slides outward to the predetermined stroke, the drilling diameter of the hollow internal slag discharge variable diameter drill bit increases and eventually remains at a fixed value. At this time, the PVC hole protection pipe gradually follows When the force on the front end of the drill bit disappears, the telescopic column will return to its initial position. At this time, the hollow internal slag discharge variable diameter drill bit and the hollow smooth drill rod can be pulled out, and the PVC hole protection pipe can be left in the hole to discharge the gas smoothly. However, when the PVC hole protection pipe follows the drill bit to drill, there is still a gap between the PVC hole protection pipe and the mining hole, which makes the PVC hole protection pipe unable to play the role of hole protection during the drilling process. At the same time, when the drill bit is pulled out, the mining hole and the PVC hole protection pipe are not fixed, which causes the PVC hole protection pipe to be pulled out at the same time as the drill bit, and the PVC hole protection pipe cannot be left in the hole to discharge the gas. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems in the background technology and to propose a layered cutting and drilling method and drilling tool for soft coal seams.

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

[0005] The tool is adapted to engage a plurality of guide wheels, the guide wheels being adapted to engage with the guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels, the guide wheels being adapted to engage with the second guide wheels,

[0006] A water sprinkler is fixedly installed between the first drill rod and the drill bit. A water sprinkler assembly is movably installed inside the water sprinkler. The water sprinkler assembly is used to wet the debris to facilitate the discharge of the debris.

[0007] In the above-mentioned soft coal seam layered cutting drill tool, the side walls of the first drill rod and the second drill rod are respectively provided with three discharge grooves 1 and three discharge grooves 2, and the side circumferential walls of the first drill rod and the second drill rod are respectively provided with spiral groove 1 and spiral groove 2.

[0008] In the above-mentioned soft coal seam layered cutting drill tool, three support rods are welded to the inner wall of the rotating ring, and the support rods correspond one to one with the discharge trough 2. The side wall of each support rod is integrally formed with a stirring rod, and the stirring rod is located inside the discharge trough 2.

[0009] In the above-mentioned soft coal seam layered cutting drill tool, a protrusion is integrally formed on the inner wall of the sliding hole, and the protrusion is slidably installed inside the second discharge chute.

[0010] In the above-mentioned soft coal seam layered cutting drill tool, the outer peripheral wall of the casing is integrally formed with a thread 1, the inner wall of the casing close to the drill bit 2 is provided with an annular groove, the side wall of the support rod is integrally formed with a convex tooth, the convex tooth is movably installed inside the annular groove, and the side wall of the annular groove is integrally formed with a slope 2.

[0011] In the above-mentioned soft coal seam layered cutting drill tool, a slide groove 1 is opened inside the movable groove, and a slider 1 is integrally formed on the side wall of the sliding blade. The slider 1 is slidably installed inside the slide groove 1. A spring 2 is provided between the side wall of the movable groove and the side wall of the sliding blade, and the side wall of the sliding blade is integrally formed with a slope 1.

[0012] In the above-mentioned soft coal seam layered cutting drill tool, the water spray assembly includes a nozzle and a sliding cover, the nozzle is fixedly installed on the side wall of the sprinkler, and the sliding cover is slidably installed inside the sprinkler. A water inlet channel is opened inside the first drill rod, and the water inlet channel and the interior of the sprinkler are connected to each other. A spring is provided between the sliding cover and the side wall of the water inlet channel.

[0013] In the above-mentioned soft coal seam layered cutting drill tool, a sliding tube is fixedly installed inside the recovery chamber, and the sliding tube is slidably installed inside the water inlet channel. The side walls of the water inlet channel and drill bit 1 are both provided with air holes, and the two air holes are connected to each other. The air holes are located on the side wall of spring 1.

[0014] A layered cutting and drilling method for soft coal seams uses the above-mentioned layered cutting drill tool for soft coal seams, specifically comprising the following steps: S1, starting an external driving device, the second drill rod drives the drill bit 2, the first drill rod, the water sprinkler and the drill bit 1 to drill, the external high-pressure water injection device injects water into the interior of the water inlet channel, so that the first drill rod drives the water sprinkler and the drill bit 1 to move out of the recovery chamber, the drill bit 1 and the drill bit 2 successively drill into the soft coal seam, thereby realizing layered cutting and drilling; S2, during the drilling process, the sliding blade pulls the casing so that the casing rotates with the drill bit 2, the thread 1 squeezes the debris between the outer side of the casing and the inner wall of the mining hole, so that the debris forms a thread shape, the threaded debris and the thread 1 cooperate with each other and are evenly distributed on the outer side of the casing, thereby increasing the contact area between the casing and the mining hole, and improving the anti-collapse strength of the mining hole; S3, when the drill bit 2 is driven During the rotation of the movable casing, the pitch of thread one is greater than the distance drilled per circle by drill bit two, so that the casing moves intermittently inside the mining hole. When the casing stops rotating, the second drill rod drives the rotating ring to rotate through the support rod, and the stirring rod rotates with the rotating ring, so that the support rod and the stirring rod stir the debris between the second drill rod and the casing, loosening the debris. The loose debris reduces the vibration of the second drill rod on the casing, and improves the anti-collapse strength of the mining hole; S4. After the drilling is completed, the external high-pressure water injection device extracts the water source inside the water inlet channel, so that the first drill rod, the sprinkler and the drill bit one move toward the recovery chamber, and the external drive device pulls the second drill rod toward the outside of the mining hole. The casing is fixed inside the mining hole by the cooperation of thread one and the threaded debris, and the sliding blade slides toward the inside of the movable groove, so that the drill bit two enters the inside of the casing and moves toward the outside of the mining hole.

[0015] Compared with the existing technology, the beneficial effects of the present invention are:

[0016] The casing is movably mounted on the side wall of the sliding blade, so that during the drilling process, the sliding blade drives the casing to perform intermittent drilling, so that the casing always follows the drill bit for synchronous drilling. During the casing drilling process, when the casing follows the drill bit for drilling, the thread 1 on the outside of the casing squeezes the debris between the outside of the casing and the inner wall of the production hole, so that the debris forms a thread shape. The thread-shaped debris and the thread 1 cooperate with each other and are evenly distributed on the outside of the casing, thereby increasing the contact area between the casing and the production hole and improving the anti-collapse strength of the production hole. When the casing stops rotating, the second drill rod drives the swivel to rotate, causing the support rod and the stirring rod to stir and loosen the debris between the second drill rod and the casing. The loosened debris reduces the vibration of the second drill rod on the casing during drilling, thereby improving the anti-collapse strength of the production hole. At the end of drilling, the casing is fixed inside the production hole through the cooperation of the thread 1 and the thread-shaped debris, so that after the second drill rod is removed, the casing still remains stably inside the production hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0018] Figure 2 It is a cross-sectional view of the overall structure of the present invention;

[0019] Figure 3 For the present invention Figure 2 A magnified schematic diagram of point A in the middle;

[0020] Figure 4 For the present invention Figure 2 A magnified schematic diagram of point B in the middle;

[0021] Figure 5 It is a side view of the overall structure of the present invention;

[0022] Figure 6 This is a disassembly diagram of the sleeve and swivel in the present invention;

[0023] Figure 7 Schematic diagram of the structure of the sliding blade in the present invention;

[0024] Figure 8 For the present invention Figure 7 Enlarged schematic diagram of point C in the middle.

[0025] In the figure: 1. first drill rod; 11. drill bit 1; 12. sprinkler; 13. sprinkler head; 131. sliding cover; 132. spring 1; 133. air hole; 14. discharge trough 1; 15. spiral groove 1; 16. water inlet channel; 2. second drill rod; 21. drill bit 2; 211. bump; 212. movable groove; 213. slide 1; 214. slide hole; 22. sliding blade; 221. support rod; 222. convex tooth; 223. inclined plane 1; 224. spring 2; 225. slider 1; 23. swivel; 231. support rod; 232. stirring rod; 24. discharge trough 2; 25. spiral groove 2; 26. recovery chamber; 261. slide pipe; 31. casing; 311. thread 1; 312. annular tooth groove; 313. inclined plane 2. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0028] Reference Figure 1 - Figure 8 As shown, a soft coal seam layer cutting drill tool includes a first drill rod 1, a drill bit 11, a second drill rod 2 and a drill bit 21. The drill bit 21 is located between the first drill rod 1 and the second drill rod 2. The drill bit 21 is fixedly installed on the side wall of the second drill rod 2. A recovery cavity 26 and a sliding hole 214 are respectively opened inside the second drill rod 2 and the drill bit 21. The recovery cavity 26 and the sliding hole 214 are connected to each other. The first drill rod 1 is slidably installed inside the recovery cavity 26 and the sliding hole 214. A protective component is movably installed on the outside of the second drill rod 2 to prevent The drill bit assembly includes a sliding blade 22, a sleeve 31, and several swivels 23. A movable groove 212 is formed on the side wall of the drill bit 21. The sliding blade 22 is slidably mounted inside the movable groove 212. A support rod 221 is integrally formed on the side wall of the sliding blade 22. The sleeve 31 is movably mounted on the outside of the support rod 221. The sleeve 31 is located on the outside of the second drill rod 2. Each swivel 23 is rotatably mounted inside the sleeve 31. The swivel 23 is located between the sleeve 31 and the second drill rod 2. The swivels 23 are evenly distributed inside the sleeve 31.

[0029] A water sprinkler 12 is fixedly installed between the first drill rod 1 and the drill bit 11. A water sprinkler assembly is movably installed inside the water sprinkler 12. The water sprinkler assembly is used to wet the debris to facilitate the discharge of the debris.

[0030] like Figure 1 、 Figure 2 and Figure 5 As shown, the side walls of the first drill rod 1 and the second drill rod 2 are respectively provided with three discharge grooves 14 and three discharge grooves 24, and the side walls of the first drill rod 1 and the second drill rod 2 are respectively provided with a spiral groove 15 and a spiral groove 25.

[0031] During the rotation of the first drill rod 1 and the second drill rod 2, the spiral groove 15 and the spiral groove 2 25 transport the debris inside the mining hole to the inside of the discharge trough 14 and the discharge trough 2 24, and the debris is discharged from the mining hole through the discharge trough 14 and the discharge trough 2 24.

[0032] like Figure 4 、 Figure 6 and Figure 8As shown, the outer peripheral wall of the sleeve 31 is integrally formed with a thread 1 311, the inner wall of the sleeve 31 close to the drill bit 21 is provided with an annular tooth groove 312, the side wall of the support rod 221 is integrally formed with a convex tooth 222, the convex tooth 222 is movably installed inside the annular tooth groove 312, and the side wall of the annular tooth groove 312 is integrally formed with a slope 2 313.

[0033] like Figure 4 、 Figure 7 and Figure 8 As shown, a slide groove 213 is provided inside the movable groove 212, and a slider 225 is integrally formed on the side wall of the sliding blade 22. The slider 225 is slidably installed inside the slide groove 213. A spring 224 is provided between the side wall of the movable groove 212 and the side wall of the sliding blade 22, and a slope 223 is integrally formed on the side wall of the sliding blade 22.

[0034] Among them, the working principle of the sliding blade 22 is: during the rotation of the second drill rod 2, the sliding blade 22 rotates with the drill bit 21, and the spring 224 resists the sliding blade 22, so that the slider 1 225 moves to the end of the slide groove 1 213. At this time, the sliding blade 22 and the drill bit 21 reach the maximum drilling diameter. When the second drill rod 2 is taken out, the inclined surface 1 223 resists the side wall of the casing 31, and the sliding blade 22 contracts, so that the second drill rod 2 drives the drill bit 21 and the sliding blade 22 to move to the inside of the casing 31. At this time, the external drilling equipment takes out the drill bit 21 and the sliding blade 22 through the second drill rod 2.

[0035] Further references Figure 4 and Figure 8 To illustrate, the working principle of the casing 31 is as follows: when the sliding blade 22 and the drill bit 21 reach the maximum drilling diameter, the sliding blade 22 drives the convex teeth 222 to slide inside the annular tooth groove 312, and the convex teeth 222 abut against the side wall of the annular tooth groove 312, so that the casing 31 rotates along with the drill bit 21, and the thread 1 311 squeezes the debris on the outside of the casing 31, so that the debris forms a thread shape and is threadedly matched with the thread 1 311, thereby improving the stability of the casing 31 inside the mining hole. In the process of mutual cooperation between the thread 1 311 and the debris, as the drilling distance of each circle of the drill bit 21 is less than the pitch of the thread 1 311, the convex teeth 222 intermittently abut the side wall of the annular tooth groove 312, and the casing 31 continuously follows the drill bit 21 to move inside the mining hole. When the second drill rod 2 is removed, the casing 31 is fixed inside the mining hole by the thread formed by the debris abutting the thread 1 311.

[0036] like Figure 2 and Figure 5-Figure 7As shown, three support rods 231 are welded to the inner wall of the rotating ring 23, and the support rods 231 correspond to the discharge trough 24 one by one. The side wall of each support rod 231 is integrally formed with a stirring rod 232, and the stirring rod 232 is located inside the discharge trough 24. The inner wall of the sliding hole 214 is integrally formed with a protrusion 211, and the protrusion 211 is slidably installed inside the discharge trough 24.

[0037] Among them, the working principle of the swivel 23 is: when the casing 31 stops rotating, the second drill rod 2 contacts the support rod 231, so that the swivel 23 rotates with the second drill rod 2, and the support rod 231 drives the stirring rod 232 to stir the debris between the casing 31 and the second drill rod 2, so that the debris is loose, and the loose debris reduces the vibration of the second drill rod 2 on the casing 31 when drilling. In the process of the casing 31 discharging gas inside the mining hole, when the mining hole collapses, the mining hole squeezes the casing 31, and the casing 31 is squeezed and deformed, and the swivel 23 is deformed, so that the stirring rod 232 contacts the inner wall of the casing 31. At this time, the swivel 23 supports the casing 31 through the stirring rod 232 and the support rod 231, so that the casing 31 is elliptical and continues to discharge gas, avoiding the mining hole from being completely closed and the gas cannot be discharged.

[0038] like Figure 1-Figure 3 As shown, the water spray assembly includes a nozzle 13 and a sliding cover 131. The nozzle 13 is fixedly mounted on the side wall of the sprinkler 12. The sliding cover 131 is slidably mounted inside the sprinkler 12. A water inlet channel 16 is provided inside the first drill rod 1. The water inlet channel 16 and the interior of the sprinkler 12 are communicated with each other. A spring 132 is provided between the sliding cover 131 and the side wall of the water inlet channel 16. A sliding tube 261 is fixedly mounted inside the recovery chamber 26. The sliding tube 261 is slidably mounted inside the water inlet channel 16. Air holes 133 are provided on the side walls of the water inlet channel 16 and the drill bit 11. The two air holes 133 are communicated with each other. The air holes 133 are located on the side wall of the spring 132.

[0039] Among them, the working principle of the sliding cover 131 is: when drilling, the external high-pressure water injection device injects water into the water inlet channel 16, and the high-pressure water inside the water inlet channel 16 squeezes the sliding cover 131, so that the nozzle 13 opens. When the drilling is completed, the external high-pressure water injection device extracts the water source inside the water inlet channel 16, so that the water pressure inside the water inlet channel 16 is reduced. At this time, the spring 132 resists the sliding cover 131, and the sliding cover 131 blocks the nozzle 13 to prevent the nozzle 13 from being blocked. At the same time, the first drill rod 1, the sprinkler 12 and the drill bit 11 move toward the recovery chamber 26.

[0040] A method for drilling and cutting soft coal seams using the above-mentioned soft coal seam layered cutting drill tool specifically includes the following steps: S1, starting an external drive device, the second drill rod 2 drives the drill bit 21, the first drill rod 1, the water sprayer 12 and the drill bit 11 to drill, the external high-pressure water injection device injects water into the water inlet channel 16, so that the first drill rod 1 drives the water sprayer 12 and the drill bit 11 to move out of the recovery chamber 26, and the drill bit 11 and the drill bit 21 successively drill into the soft coal seam, thereby Achieve layered cutting and drilling; S2, during the drilling process, the sliding blade 22 pulls the casing 31, so that the casing 31 rotates along with the drill bit 21, and the thread 1 311 squeezes the debris between the outer side of the casing 31 and the inner wall of the mining hole, so that the debris forms a thread shape, and the thread-shaped debris and the thread 1 311 cooperate with each other and are evenly distributed on the outer side of the casing 31, thereby increasing the contact area between the casing 31 and the mining hole and improving the anti-collapse strength of the mining hole; S3, when the drill bit 21 drives the casing 31 to rotate During the drilling process, the pitch of the first thread 311 is greater than the distance drilled per turn by the second drill bit 21, so that the casing 31 moves intermittently inside the mining hole. When the casing 31 stops rotating, the second drill rod 2 drives the rotating ring 23 to rotate through the support rod 231, and the stirring rod 232 rotates along with the rotating ring 23, so that the support rod 231 and the stirring rod 232 stir the debris between the second drill rod 2 and the casing 31, loosening the debris. The loosened debris reduces the vibration of the second drill rod 2 on the casing 31, thereby improving the drilling efficiency. Strength of preventing the mining hole from collapsing; S4. After drilling is completed, the external high-pressure water injection device draws out the water source inside the water inlet channel 16, so that the first drill rod 1, the sprinkler 12 and the drill bit 11 move toward the recovery chamber 26, and the external drive device pulls the second drill rod 2 toward the outside of the mining hole. The casing 31 is fixed to the inside of the mining hole by the cooperation of the thread 1 311 and the threaded debris, and the sliding blade 22 slides toward the inside of the movable groove 212, so that the drill bit 21 enters the inside of the casing 31 and moves toward the outside of the mining hole.

[0041] It is further explained that the above-mentioned fixed connection should be understood in a broad sense unless otherwise clearly specified and limited. For example, it can be welding, gluing, or one-piece molding, etc., which are common means well known to those skilled in the art.

[0042] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A soft coal seam layer cutting drill tool, comprising a first drill rod (1), a first drill bit (11), a second drill rod (2) and a second drill bit (21), characterized in that: The second drill bit (21) is located between the first drill rod (1) and the second drill rod (2). The second drill bit (21) is fixedly mounted on the side wall of the second drill rod (2). A recovery chamber (26) is provided inside the second drill rod (2). A sliding hole (214) is provided inside the second drill bit (21). The recovery chamber (26) and the sliding hole (214) are communicated with each other. The first drill rod (1) is slidably mounted inside the recovery chamber (26) and the sliding hole (214). A protective component is movably mounted on the outside of the second drill rod (2). The protective component includes a sliding blade (22), a casing (31) and a plurality of A rotating ring (23), a movable groove (212) is provided on the side wall of the second drill bit (21), the sliding blade (22) is slidably mounted inside the movable groove (212), a support rod (221) is integrally formed on the side wall of the sliding blade (22), the sleeve (31) is movably sleeved on the outside of the support rod (221), the sleeve (31) is located on the outside of the second drill rod (2), each rotating ring (23) is rotatably mounted inside the sleeve (31), the rotating ring (23) is located between the sleeve (31) and the second drill rod (2), and the rotating rings (23) are evenly distributed inside the sleeve (31); A water sprayer (12) is fixedly installed between the first drill rod (1) and the drill bit (11), and a water spray assembly is movably installed inside the water sprayer (12), and the water spray assembly is used to wet the debris to facilitate the discharge of the debris; The outer peripheral wall of the sleeve (31) is integrally formed with a first thread (311); the inner wall of the sleeve (31) on the side close to the second drill bit (21) is provided with an annular tooth groove (312); the side wall of the support rod (221) is integrally formed with a convex tooth (222); the convex tooth (222) is movably mounted inside the annular tooth groove (312); the side wall of the annular tooth groove (312) is integrally formed with a second inclined surface (313); The drilling distance per turn of the drill bit 2 (21) is smaller than the pitch of the thread 1 (311), so that the convex teeth (222) intermittently abut against the side wall of the annular tooth groove (312).

2. The soft coal seam layer cutting drill according to claim 1, characterized in that: The side walls of the first drill rod (1) and the second drill rod (2) are respectively provided with three discharge grooves 1 (14) and three discharge grooves 2 (24), and the side circumferential walls of the first drill rod (1) and the second drill rod (2) are respectively provided with a spiral groove 1 (15) and a spiral groove 2 (25).

3. The soft coal seam layer cutting drill tool according to claim 2, characterized in that: Three support rods (231) are welded to the inner wall of the rotating ring (23), and the support rods (231) correspond to the second discharge trough (24) one by one. A stirring rod (232) is integrally formed on the side wall of each support rod (231), and the stirring rod (232) is located inside the second discharge trough (24).

4. The soft coal seam layer cutting drill according to claim 2, characterized in that: The inner wall of the sliding hole (214) is integrally formed with a protrusion (211), and the protrusion (211) is slidably mounted inside the second discharge trough (24).

5. The soft coal seam layer cutting drill tool according to claim 1, characterized in that: A sliding groove (213) is provided inside the movable groove (212), a slider (225) is integrally formed on the side wall of the sliding blade (22), and the slider (225) is slidably installed inside the sliding groove (213). A spring (224) is provided between the side wall of the movable groove (212) and the side wall of the sliding blade (22), and a slope (223) is integrally formed on the side wall of the sliding blade (22).

6. The soft coal seam layer cutting drill tool according to claim 1, characterized in that: The water spray assembly comprises a spray head (13) and a sliding cover (131), wherein the spray head (13) is fixedly mounted on the side wall of the water sprayer (12), and the sliding cover (131) is slidably mounted inside the water sprayer (12). A water inlet channel (16) is provided inside the first drill rod (1), and the water inlet channel (16) and the inside of the water sprayer (12) are communicated with each other. A spring (132) is provided between the sliding cover (131) and the side wall of the water inlet channel (16).

7. The soft coal seam layer cutting drill tool according to claim 6, characterized in that: A sliding tube (261) is fixedly installed inside the recovery chamber (26), and the sliding tube (261) is slidably installed inside the water inlet channel (16). The side walls of the water inlet channel (16) and the drill bit (11) are both provided with air holes (133), and the two air holes (133) are interconnected. The air holes (133) are located on the side wall of the spring (132).

8. A layered cutting and drilling method for soft coal seams, characterized by: The drilling method uses a soft coal seam layer cutting drill tool as described in any one of claims 1 to 7, and specifically comprises the following steps: S1. Start the external driving device, the second drill rod (2) drives the drill bit 2 (21), the first drill rod (1), the water sprayer (12) and the drill bit 1 (11) to drill, the external high-pressure water injection device injects water into the water inlet channel (16), so that the first drill rod (1) drives the water sprayer (12) and the drill bit 1 (11) to move out of the recovery chamber (26), and the drill bit 1 (11) and the drill bit 2 (21) drill into the soft coal seam in sequence, thereby realizing layered cutting drilling; S2. During the drilling process, the sliding blade (22) pulls the casing (31), causing the casing (31) to rotate along with the drill bit (21). The thread (311) squeezes the debris between the outer side of the casing (31) and the inner wall of the mining hole, causing the debris to form a thread shape. The thread-shaped debris and the thread (311) cooperate with each other and are evenly distributed on the outer side of the casing (31), thereby increasing the contact area between the casing (31) and the mining hole and improving the anti-collapse strength of the mining hole. S3. During the process of the second drill bit (21) driving the casing (31) to rotate, the pitch of the first thread (311) is greater than the distance drilled per turn by the second drill bit (21), so that the casing (31) moves intermittently inside the mining hole. When the casing (31) stops rotating, the second drill rod (2) drives the rotating ring (23) to rotate through the support rod (231), and the stirring rod (232) rotates along with the rotating ring (23), so that the support rod (231) and the stirring rod (232) stir the debris between the second drill rod (2) and the casing (31), loosening the debris. The loosened debris reduces the vibration of the second drill rod (2) on the casing (31), thereby improving the anti-collapse strength of the mining hole; S4. After drilling is completed, the external high-pressure water injection device extracts the water source inside the water inlet channel (16), so that the first drill rod (1), the water sprayer (12) and the drill bit (11) move toward the recovery chamber (26). The external driving device pulls the second drill rod (2) toward the outside of the mining hole. The casing (31) is fixed inside the mining hole through the cooperation of the thread (311) and the threaded debris. The sliding blade (22) slides toward the inside of the movable groove (212), so that the drill bit (21) enters the inside of the casing (31) and moves toward the outside of the mining hole.

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