A tunnel crown drilling apparatus and method of use thereof

Abstract

The application discloses a tunnel vault drilling equipment and a use method thereof and relates to the technical field of tunnel construction, which comprises a drill bit, a driving assembly in transmission connection with the drill bit, a top plate fixedly connected with the driving assembly, a collecting box located directly below the drill bit, a rotating assembly provided outside the collecting box and fixedly connected with the side wall of the top plate, an adjusting mechanism comprising a sliding seat, a first hydraulic cylinder fixedly connected with the top surface of the sliding seat, an output end of the first hydraulic cylinder fixedly connected with the bottom surface of the top plate, a bottom plate installed below the sliding seat and fixedly connected with the ground. The application can collect stones and dust generated during drilling, improve safety, has a multi-angle adjusting function, can realize drilling in different directions, has a wider application range and is high in construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a tunnel arch drilling device and its method of use. Background Technology

[0002] With the development of science and technology and the progress of society, my country's economy has developed rapidly. Roads are the vanguard of wealth. In mountainous areas, tunnel excavation is the main method. In recent years, the development and utilization of underground space has received increasing attention in the transportation field. Some embedded parts often need to be installed on the top of the tunnel, so drilling is required for the arch.

[0003] However, existing drilling equipment does not have the function of collecting debris or stones generated during drilling, which causes them to fall on the machine. The accumulation of dust over a long period of time can easily cause the machine to overheat and be damaged, or stones to get stuck in the transmission parts, causing it to stop operating. In addition, it does not have the function of multi-angle adjustment, making it extremely inconvenient to use.

[0004] Therefore, there is an urgent need for a tunnel arch drilling device and its usage method to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a tunnel arch drilling device and its usage method to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a tunnel arch drilling device and its method of use, comprising:

[0007] A drill bit, wherein the drill bit is driven by a drive assembly, and the drive assembly is fixedly connected to a top plate;

[0008] A collection box is located directly below the drill bit, and a rotating assembly is provided on the outside of the collection box. The rotating assembly is fixedly connected to the side wall of the top plate.

[0009] An adjustment mechanism is provided, comprising a sliding seat, a first hydraulic cylinder fixedly connected to the top surface of the sliding seat, the output end of the first hydraulic cylinder being fixedly connected to the bottom surface of the top plate, and a base plate installed below the sliding seat, the base plate being fixedly connected to the ground.

[0010] Preferably, the rotating assembly includes connecting rods symmetrically fixed to the side wall of the top plate, a first rotating shaft symmetrically rotatably connected between the two connecting rods, a square frame fixedly connected to the end of the first rotating shaft away from the connecting rod, the square frame being fitted onto the outside of the collection box, a second rotating shaft symmetrically rotatably connected to the inside of the square frame, the end of the second rotating shaft away from the square frame being fixedly connected to the collection box, and the two first rotating shafts and the two second rotating shafts being arranged perpendicularly.

[0011] Preferably, a steel wire rope is fixedly connected to the center of the bottom surface of the collection box, and a counterweight is fixedly connected to the bottom of the steel wire rope.

[0012] Preferably, a connecting plate is slidably connected to the bottom surface of the sliding seat, and fixing strips are symmetrically fixed to both sides of the connecting plate. Arc-shaped grooves are symmetrically opened in the fixing strips. Sliding wheels are symmetrically rotatably connected to the side wall of the sliding seat. The sliding wheels are adapted to the arc-shaped grooves. The distance between the two sliding wheels is less than the distance between the two arc-shaped grooves. An adjustment component is fixed to either side of the sliding seat.

[0013] Preferably, the adjusting assembly includes an L-shaped plate fixedly connected to the sliding seat, a connecting shaft fixedly connected to the side of the L-shaped plate away from the sliding seat, a connecting block provided at the end of the connecting shaft away from the L-shaped plate, a limiting groove formed in the connecting block, the end of the connecting shaft located in the limiting groove and slidably connected to the limiting groove, and a sliding component fixedly connected to the side of the connecting block away from the connecting shaft, the sliding component being fixedly connected to the side wall of the fixing strip.

[0014] Preferably, the sliding assembly includes a slider fixedly connected to the connecting block, a side plate on the outer side of the slider, the side plate being fixedly connected to the side wall of the fixing strip, a groove on the top of the side plate, the slider being located in the groove and slidably connected to the groove, a chain being fixedly connected through the slider, gears meshing at both ends of the chain, the two gears being rotatably connected to the side plate, and the output shaft of a second motor being fixedly connected to the center of any one of the gears, the second motor being fixedly connected to the side plate via an oblique support.

[0015] Preferably, a hinge seat is symmetrically hinged to one side of the bottom surface of the connecting plate, the bottom of the hinge seat is fixedly connected to the base plate, and the output end of a second hydraulic cylinder is hinged to the side of the bottom surface of the connecting plate away from the hinge seat, the bottom of the second hydraulic cylinder is hinged to the base plate.

[0016] Preferably, the drive assembly includes a first motor fixedly connected to the top surface of the top plate, a first transmission wheel fixedly connected to the output end of the first motor, a second transmission wheel connected to the first transmission wheel via a belt drive, and the second transmission wheel being drive-connected to the drill bit.

[0017] A method for using a tunnel arch drilling device includes the following steps:

[0018] Move the entire assembly to the location where drilling is required;

[0019] Adjust the drilling angle using the adjustment mechanism;

[0020] Install the drill bit, limit the drill bit using the limiting component, start the first motor to make the drill bit start rotating;

[0021] The first hydraulic cylinder is activated to extend it and drill a hole at the target location;

[0022] The collection box collects the debris generated during drilling, thus completing the drilling process.

[0023] Preferably, the limiting component includes a fixing plate fixedly connected to the top plate, a sleeve fixedly connected to the end of the fixing plate, the sleeve being sleeved on the outer side of the bottom of the drill bit, a fixing seat rotatably connected inside the sleeve, a plurality of grooves being circumferentially formed on the top surface of the fixing seat, a plurality of protrusions being circumferentially fixedly connected to the bottom of the drill bit, the protrusions being adapted to the grooves, a transmission rod being fixedly connected to the bottom of the fixing seat, the transmission rod extending out of the sleeve and being fixedly connected to the second transmission wheel, an annular plate being fixedly connected to the top surface of the sleeve, a limiting disc being fixedly connected to the side wall of the drill bit, the limiting disc being located inside the annular plate, a cover plate being detachably connected to the top of the annular plate, and the bottom surface of the cover plate contacting the limiting disc.

[0024] This invention discloses the following technical effects: By adjusting the mechanism to rotate the first hydraulic cylinder and its upper part, the drilling angle is adjusted. Then, the drive assembly is activated to rotate the drill bit. Debris generated during drilling falls into the collection box, preventing it from hitting workers or accumulating on the machine, thus improving safety. The drill bit is offset from the overall structure, so even if it doesn't fall into the collection box, it won't fall onto the machine, further protecting it from damage, saving maintenance costs, reducing the damage rate, and improving work efficiency. This invention can collect stones and dust generated during drilling, improving safety, and has a multi-angle adjustment function, enabling drilling from different directions, thus broadening its applicability and increasing construction efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the present invention;

[0027] Figure 2 This is the front view of the present invention;

[0028] Figure 3 This is a schematic diagram of the adjustment mechanism of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the sliding component of the present invention;

[0030] Figure 5 This is a schematic diagram of the internal structure of the sleeve of the present invention;

[0031] Figure 6 This is a top view of the sleeve of the present invention;

[0032] Figure 7 This is a top view of the fixing base of the present invention;

[0033] Figure 8 This is a schematic diagram of the buckle structure of the present invention;

[0034] Figure 9 This is a top view of the collection box of the present invention;

[0035] The components are as follows: 1. Base plate; 2. Connecting plate; 3. Sliding seat; 4. Fixing strip; 5. Side plate; 6. Hinge seat; 7. First hydraulic cylinder; 8. Top plate; 9. First motor; 10. First transmission wheel; 11. Fixing plate; 12. Sleeve; 13. Drill bit; 14. Collection box; 15. Counterweight; 16. Connecting rod; 17. First rotating shaft; 18. Square frame; 19. Second rotating shaft; 20. Second transmission wheel; 21. 21. Second hydraulic cylinder; 22. Sliding wheel; 23. L-shaped plate; 24. Connecting shaft; 25. Connecting block; 26. Limiting groove; 27. Arc groove; 28. Slider; 29. ​​Slide groove; 30. Gear; 31. Chain; 32. Second motor; 33. Diagonal support; 34. Buckle; 35. Transmission rod; 36. Fixed seat; 37. Annular plate; 38. Cover plate; 39. Limiting disc; 40. Groove; 41. Protrusion. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Reference Figures 1-9 This invention provides a tunnel arch drilling device and its method of use, comprising:

[0039] Drill bit 13, the drill bit 13 is connected to a drive assembly, and the drive assembly is fixed to a top plate 8;

[0040] Collection box 14 is located directly below drill bit 13. A rotating component is provided on the outside of collection box 14, and the rotating component is fixedly connected to the side wall of top plate 8.

[0041] The adjustment mechanism includes a sliding seat 3, a first hydraulic cylinder 7 is fixedly connected to the top surface of the sliding seat 3, the output end of the first hydraulic cylinder 7 is fixedly connected to the bottom surface of the top plate 8, and a base plate 1 is installed below the sliding seat 3 and is fixedly connected to the ground.

[0042] The adjusting mechanism drives the first hydraulic cylinder 7 and its upper part to rotate, adjusting the drilling angle. Then, the drive assembly is activated to rotate the drill bit 13. Debris generated during drilling falls into the collection box 14, preventing it from hitting workers or accumulating on the machine, thus improving safety. The drill bit 13 is offset from the rest of the machine, so even if it doesn't fall into the collection box 14, it won't fall onto the machine, further protecting it from damage, saving maintenance costs, reducing damage rates, and improving work efficiency. This invention can collect stones and dust generated during drilling, improving safety, and has a multi-angle adjustment function, enabling drilling from different directions, thus broadening its applicability and increasing construction efficiency.

[0043] The design is further optimized by including connecting rods 16 symmetrically fixed to the sidewalls of the top plate 8. A first rotating shaft 17 is symmetrically rotatably connected between the two connecting rods 16. A square frame 18 is fixedly connected to the end of the first rotating shaft 17 away from the connecting rods 16. The square frame 18 is fitted onto the outside of the collection box 14. A second rotating shaft 19 is symmetrically rotatably connected to the inside of the square frame 18. The end of the second rotating shaft 19 away from the square frame 18 is fixedly connected to the collection box 14. The two first rotating shafts 17 and the two second rotating shafts 19 are perpendicular to each other. Regardless of whether the angle is adjusted horizontally or vertically, the rotation of the first rotating shaft 17 and the second rotating shaft 19 keeps the collection box 14 vertically downward, preventing the collection box 14 from tilting and spilling stones, thus demonstrating strong adaptability.

[0044] In a further optimized design, a steel wire rope is fixedly connected to the center of the bottom surface of the collection box 14, and a counterweight 15 is fixedly connected to the bottom of the steel wire rope. The counterweight 15 connected to the steel wire rope is located at the exact center of the collection box 14, which helps to keep the collection box 14 in a horizontal position.

[0045] The design is further optimized by slidably connecting a connecting plate 2 to the bottom surface of the sliding seat 3. Fixing strips 4 are symmetrically fixed to both sides of the connecting plate 2, and symmetrically formed arc-shaped grooves 27 are formed within the fixing strips 4. Sliding wheels 22 are symmetrically rotatably connected to the side walls of the sliding seat 3. The sliding wheels 22 are adapted to the arc-shaped grooves 27, and the distance between the two sliding wheels 22 is less than the distance between the two arc-shaped grooves 27. An adjustment component is fixed to either side of the sliding seat 3. When the adjustment component drives the sliding seat 3 to slide in any direction, the sliding seat 3 drives the sliding wheels 22 to slide within the fixing strips 4. When one sliding wheel 22 slides into the arc-shaped groove 27, it stops moving. At this time, the other sliding wheel 22 tilts up, causing the sliding seat 3 to rotate, thereby adjusting the overall tilt angle. Conversely, sliding in the other direction causes the entire structure to rotate in the other direction, achieving bidirectional adjustment. This allows for drilling at different angles, improving work efficiency.

[0046] The scheme is further optimized. The adjusting component includes an L-shaped plate 23 fixedly connected to the sliding seat 3. A connecting shaft 24 is fixedly connected to the side of the L-shaped plate 23 away from the sliding seat 3. A connecting block 25 is provided at the end of the connecting shaft 24 away from the L-shaped plate 23. The connecting block 25 has a limiting groove 26. The end of the connecting shaft 24 is located in the limiting groove 26 and is slidably connected to the limiting groove 26. A sliding component is fixedly connected to the side of the connecting block 25 away from the connecting shaft 24. The sliding component drives the connecting block 25 to move, the connecting block 25 drives the connecting shaft 24 and the L-shaped plate 23 to move, and the L-shaped plate 23 drives the sliding seat 3 to move, thereby completing the angle adjustment. When the sliding seat 3 rotates, the L-shaped plate 23 rotates accordingly, so that the connecting shaft 24 slides in the limiting groove 26, ensuring the normal operation of the transmission.

[0047] A further optimized design includes a sliding component comprising a slider 28 fixedly connected to a connecting block 25. A side plate 5 is provided on the outer side of the slider 28, and the side plate 5 is fixedly connected to the side wall of the fixing strip 4. A groove 29 is formed at the top of the side plate 5, and the slider 28 is located within and slidably connected to the groove 29. A chain 31 is fixedly connected through the slider 28, and gears 30 are meshed at both ends of the chain 31. The two gears 30 are rotatably connected to the side plate 5. The output shaft of a second motor 32 is fixedly connected to the center of any gear 30. The second motor 32 is fixedly connected to the side plate 5 via a diagonal support 33. The second motor 32 drives the gears 30 to rotate, which in turn drives the chain 31 to rotate. The chain 31 then drives the slider 28 to slide within the groove 29, thereby achieving angle adjustment. The diagonal support 33 fixes the second motor 32, and the groove 29 limits the slider 28, ensuring transmission stability.

[0048] In a further optimized design, hinge seats 6 are symmetrically hinged to one side of the bottom surface of the connecting plate 2. The bottom of the hinge seats 6 is fixed to the base plate 1. The output end of the second hydraulic cylinder 21 is hinged to the side of the bottom surface of the connecting plate 2 away from the hinge seats 6. The bottom of the second hydraulic cylinder 21 is hinged to the base plate 1. The hinge seats 6 provide support for one side of the connecting plate 2 and also enable rotation. A buckle 34 is detachably connected to the outside of the sliding wheel 22. When the extension or retraction of the second hydraulic cylinder 21 causes the connecting plate 2 to rotate, the buckle 34 fixes the sliding wheel 22 to prevent displacement, thereby achieving angle adjustment in the other direction and greatly improving drilling efficiency.

[0049] The scheme is further optimized. The drive assembly includes a first motor 9 fixedly connected to the top surface of the top plate 8. A first transmission wheel 10 is fixedly connected to the output end of the first motor 9. The first transmission wheel 10 is connected to a second transmission wheel 20 via a belt drive. The second transmission wheel 20 is connected to the drill bit 13. The first motor 9 drives the first transmission wheel 10 to rotate, and the first transmission wheel 10 drives the second transmission wheel 20 to rotate via the belt. The second transmission wheel 20 drives the drill bit 13 to rotate, thereby achieving the purpose of drilling.

[0050] A method for using a tunnel arch drilling device includes the following steps:

[0051] Move the entire assembly to the location where drilling is required;

[0052] The rotation of the sliding plate or the rotation of the connecting plate 2 drives the first hydraulic cylinder 7 and the upper part to rotate, thereby tilting the drill bit 13 and adjusting it to the required drilling angle.

[0053] Install drill bit 13, limit drill bit 13 by limiting component, start first motor 9, drive drill bit 13 to start rotating;

[0054] The first hydraulic cylinder 7 is activated to extend it, bringing the drill bit 13 close to the target position until it contacts the arch and drills a hole;

[0055] The collection box 14 is always kept in a vertically downward position to collect the debris generated during drilling, thus completing the drilling process.

[0056] The scheme is further optimized. The limiting component includes a fixed plate 11 fixedly connected to the top plate 8. A sleeve 12 is fixedly connected to the end of the fixed plate 11. The sleeve 12 is sleeved on the outer side of the bottom of the drill bit 13. A fixed seat 36 is rotatably connected inside the sleeve 12. Several grooves 40 are circumferentially opened on the top surface of the fixed seat 36. Several protrusions 41 are circumferentially fixed to the bottom of the drill bit 13. The protrusions 41 are adapted to the grooves 40. A transmission rod 35 is fixedly connected to the bottom of the fixed seat 36. The transmission rod 35 extends out of the sleeve 12 and is fixedly connected to the second transmission wheel 20. An annular plate 37 is fixedly connected to the top surface of the sleeve 12. A limiting disc 39 is fixedly connected to the side wall of the drill bit 13. The limiting disc 39 is located inside the annular plate 37. A cover plate 38 is detachably connected to the top of the annular plate 37. The bottom surface of the cover plate 38 contacts the limiting disc 39. The first motor 9 drives the second transmission wheel 20 to rotate, the second transmission wheel 20 drives the transmission rod 35 to rotate, the transmission rod 35 drives the fixed seat 36 to rotate, and the fixed seat 36 drives the drill bit 13 to rotate, thereby completing the drilling work. The fixed plate 11 and the sleeve 12 support and fix the drill bit 13 to ensure the drilling accuracy. The groove 40 and the protrusion 41 allow the fixed seat 36 to drive the drill bit 13 to rotate, and facilitate disassembly and installation. The limiting disc 39 is located inside the annular plate 37 and is limited by the cover plate 38 to ensure that the drill bit 13 will not have vertical displacement, thereby ensuring the smooth progress of the drilling work. At the same time, it is convenient to replace and disassemble the drill bit 13 to adapt to different situations.

[0057] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "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 are not intended to 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.

[0058] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A drilling device for tunnel arches, characterized in that, include: Drill bit (13), the drill bit (13) is connected to a drive assembly, the drive assembly is fixed to a top plate (8); Collection box (14), the collection box (14) is located directly below the drill bit (13), and a rotating component is provided on the outside of the collection box (14), the rotating component being fixedly connected to the side wall of the top plate (8); The adjustment mechanism includes a sliding seat (3), a first hydraulic cylinder (7) is fixedly connected to the top surface of the sliding seat (3), the output end of the first hydraulic cylinder (7) is fixedly connected to the bottom surface of the top plate (8), and a base plate (1) is installed below the sliding seat (3) and the base plate (1) is fixedly connected to the ground. The rotating assembly includes connecting rods (16) symmetrically fixed to the side wall of the top plate (8), and a first rotating shaft (17) symmetrically rotatably connected between the two connecting rods (16). A square frame (18) is fixedly connected to one end of the first rotating shaft (17) away from the connecting rods (16). The square frame (18) is fitted on the outside of the collection box (14). A second rotating shaft (19) is symmetrically rotatably connected to the inside of the square frame (18). One end of the second rotating shaft (19) away from the square frame (18) is fixedly connected to the collection box (14). The two first rotating shafts (17) and the two second rotating shafts (19) are arranged perpendicularly. A steel wire rope is fixedly connected to the center of the bottom surface of the collection box (14), and a counterweight (15) is fixedly connected to the bottom of the steel wire rope; The bottom surface of the sliding seat (3) is slidably connected to a connecting plate (2), and the two sides of the connecting plate (2) are symmetrically fixed with fixing strips (4). The fixing strips (4) are symmetrically provided with arc grooves (27). The side wall of the sliding seat (3) is symmetrically rotatably connected with sliding wheels (22). The sliding wheels (22) are adapted to the arc grooves (27). The distance between the two sliding wheels (22) is less than the distance between the two arc grooves (27). An adjustment component is fixedly connected to either side of the sliding seat (3). The connecting plate (2) has a hinge seat (6) symmetrically hinged on one side of its bottom surface. The bottom of the hinge seat (6) is fixed to the base plate (1). The output end of the second hydraulic cylinder (21) is hinged on the side of the bottom surface of the connecting plate (2) away from the hinge seat (6). The bottom of the second hydraulic cylinder (21) is hinged to the base plate (1). The adjustment assembly includes an L-shaped plate (23) fixedly connected to the sliding seat (3). A connecting shaft (24) is fixedly connected to the side of the L-shaped plate (23) away from the sliding seat (3). A connecting block (25) is provided at the end of the connecting shaft (24) away from the L-shaped plate (23). A limiting groove (26) is provided on the connecting block (25). The end of the connecting shaft (24) is located in the limiting groove (26) and is slidably connected to the limiting groove (26). A sliding component is fixedly connected to the side of the connecting block (25) away from the connecting shaft (24). The sliding component is fixedly connected to the side wall of the fixing strip (4).

2. The tunnel arch drilling equipment according to claim 1, characterized in that: The sliding assembly includes a slider (28) fixedly connected to the connecting block (25). The slider (28) has a side plate (5) on its outer side. The side plate (5) is fixedly connected to the side wall of the fixing strip (4). The top of the side plate (5) has a groove (29). The slider (28) is located in the groove (29) and is slidably connected to the groove (29). The slider (28) is fixedly connected to a chain (31). Gears (30) are meshed at both ends of the chain (31). The two gears (30) are rotatably connected to the side plate (5). The output shaft of a second motor (32) is fixedly connected to the center of any gear (30). The second motor (32) is fixedly connected to the side plate (5) through a diagonal support (33).

3. The tunnel arch drilling equipment according to claim 1, characterized in that: The drive assembly includes a first motor (9) fixedly connected to the top surface of the top plate (8), a first transmission wheel (10) fixedly connected to the output end of the first motor (9), a second transmission wheel (20) connected to the first transmission wheel (10) via a belt drive, and the second transmission wheel (20) being connected to the drill bit (13) via a drive connection.

4. A method of using a tunnel arch drilling device, based on the tunnel arch drilling device according to claim 3, characterized in that, Includes the following steps: Move the entire assembly to the location where drilling is required; Adjust the drilling angle using the adjustment mechanism; Install the drill bit (13), limit the drill bit (13) by the limiting component, start the first motor (9) to make the drill bit (13) start to rotate; Start the first hydraulic cylinder (7) to extend it and drill a hole at the target position; The collection box (14) collects the debris generated during drilling, thus completing the drilling process.

5. The method of using the tunnel arch drilling equipment according to claim 4, characterized in that: The limiting assembly includes a fixing plate (11) fixedly connected to the top plate (8). A sleeve (12) is fixedly connected to the end of the fixing plate (11). The sleeve (12) is sleeved on the outer side of the bottom of the drill bit (13). A fixing seat (36) is rotatably connected inside the sleeve (12). A plurality of grooves (40) are circumferentially opened on the top surface of the fixing seat (36). A plurality of protrusions (41) are circumferentially fixed to the bottom of the drill bit (13). The protrusions (41) are adapted to the grooves (40). A transmission rod (35) is fixedly connected to the bottom of the seat (36). The transmission rod (35) extends out of the sleeve (12) and is fixedly connected to the second transmission wheel (20). An annular plate (37) is fixedly connected to the top surface of the sleeve (12). A limiting disc (39) is fixedly connected to the side wall of the drill bit (13). The limiting disc (39) is located inside the annular plate (37). A cover plate (38) is detachably connected to the top of the annular plate (37). The bottom surface of the cover plate (38) is in contact with the limiting disc (39).

Images