Air hammer impactor for large diameter drilling

Abstract

The application discloses an air hammer impactor for large-diameter well drilling, which comprises an outer pipe, an upper joint coaxially fixed on the upper portion of the outer pipe, a threaded hole groove arranged in the upper joint and used for connecting an outer drilling device, a conversion impact mechanism arranged in the outer pipe, and a drill bit reamer arranged in the inner portion of the outer pipe. The drill bit reamer can perform high-frequency impact drilling under the downward air pressure pushing of the conversion impact mechanism, and can perform radial reaming and impact reaming under the upward air pressure pushing of the conversion impact mechanism after reaching the drilling depth.

Description

Technical Field

[0001] This invention belongs to the field of down-the-hole hammer technology, specifically an air down-the-hole hammer impactor for large-diameter drilling. Background Technology

[0002] Air down-the-hole hammers are commonly used for breaking and drilling hard materials such as rock and concrete. They can break large blocks of rock or concrete into smaller pieces for easier cleaning and transportation. Currently, drilling costs are too high, mainly because granite in hot, dry rock formations is highly abrasive and has poor drillability. This is especially true in large-diameter drilling where conventional rotary drilling methods have low rock-breaking efficiency and rapid drill bit wear. Therefore, it is necessary to provide an air down-the-hole hammer for large-diameter drilling to solve the problems mentioned in the background. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: a large-diameter air down-the-hole hammer impactor for drilling, comprising: an outer tube with an upper connector coaxially fixed above it, the upper connector having a threaded groove for connecting an external drilling tool, a conversion impact mechanism inside the outer tube, and a drill bit reamer inside the outer tube, the drill bit reamer being capable of high-frequency impact drilling under the downward air pressure of the conversion impact mechanism, and radially expanding the hole after reaching the drilling depth, and impact reaming under the upward air pressure of the conversion impact mechanism.

[0004] Furthermore, preferably, the conversion impact mechanism includes:

[0005] The check valve seat is fixed concentrically inside the outer tube, and an airflow channel is provided in the center of the check valve seat.

[0006] A piston cylinder is fixed inside the outer tube and located below the check valve seat; the lower end of the airflow passage is connected to the piston cylinder.

[0007] A piston rod is slidably disposed within the piston cylinder, and a buffer spring is sleeved on the piston rod.

[0008] The card nest is fixed inside the outer tube and located below the piston cylinder. One end of the piston rod is slidably connected to the card nest in a sealing manner. A limit guide sleeve is provided inside the outer tube below the card nest.

[0009] A bypass channel is provided on the outer pipe side wall, and a lateral channel is provided on the check valve seat. The lateral channel is sealed and connected to the bypass channel, and the lower end of the bypass channel is connected to the piston cylinder.

[0010] The L-shaped inner tube has one end inserted into the airflow passage of the check valve seat and connected to the lateral passage.

[0011] The upper positioning spring is located inside the piston cylinder and above the piston rod.

[0012] Furthermore, as a preferred embodiment, both the airflow channel and the L-shaped inner tube are subjected to high-frequency air extraction and exhaust via an external air pressure pump.

[0013] Furthermore, preferably, the drill bit reamer includes:

[0014] An inner sleeve is disposed inside the outer tube, and a drill shaft is slidably disposed inside the inner sleeve. One end of the drill shaft is connected to the piston column in the conversion impact mechanism.

[0015] The drill bit is fixed below the drill spindle;

[0016] A spring tension ring is set in the inner sleeve and sleeved on the outside of the drill shaft;

[0017] A positioning shaft tube is slidably mounted on an outer tube. A control ring seat is fixed inside the positioning shaft tube, and the lower end of the positioning shaft tube is connected to the drill bit.

[0018] Radial actuator, fixed between the positioning shaft tube and the drill bit;

[0019] The reinforcing rods are circumferentially distributed inside the positioning shaft tube, and the two ends of the reinforcing rods are respectively connected to the control ring seat and the radial device.

[0020] Furthermore, preferably, the radial device includes:

[0021] The shaft disc has multiple mounting grooves evenly distributed on its circumferential sidewalls;

[0022] The expansion block is slidably disposed in each of the mounting slots, and a sealing cavity is provided in each mounting slot of the shaft disk;

[0023] An airflow annular chamber is located above the shaft disk and is connected to each of the sealing cavities. A shaft plug is slidably disposed in each sealing cavity, and the shaft plug is connected to the expansion block.

[0024] Furthermore, as a preferred embodiment, the cross-section of the expansion block has a right-angled trapezoidal structure.

[0025] Furthermore, as a preferred embodiment, the shaft disk is also provided with a plurality of breaking teeth, and a double-headed telescopic support rod is rotatably connected to the shaft disk, with the two ends of the double-headed telescopic support rod being connected to the expansion block and the breaking teeth, respectively.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] The present invention employs a conversion impact mechanism that can perform both downward high-frequency impact drilling and upward high-frequency impact reaming via the drill bit reamer, thereby achieving high drilling efficiency in large-diameter wells, reducing wear on the drill bit reamer end, and extending service life. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the conversion impact mechanism in this invention;

[0030] Figure 3 This is a schematic diagram of the drill bit reamer in this invention;

[0031] Figure 4 This is a schematic diagram of the radial device in this invention;

[0032] In the diagram: 1. Outer tube; 11. Upper connector; 2. Conversion impact mechanism; 21. Check valve seat; 22. Piston cylinder; 23. Piston column; 24. Buffer spring; 25. Clip nest; 26. Limiting guide sleeve; 27. Bypass channel; 28. L-shaped inner tube; 29. ​​Upper positioning spring; 3. Drill bit reamer; 31. Inner sleeve; 32. Drill spindle; 33. Spring expansion ring; 34. Drill bit; 35. Positioning shaft tube; 36. Control ring seat; 4. Radial device; 41. Shaft disc; 42. Airflow annular chamber; 43. Expanding block; 44. Sealing cavity; 45. Breaking tooth; 46. Double-headed telescopic support rod. Detailed Implementation

[0033] Please see Figure 1 In this embodiment of the invention, an air down-the-hole hammer for large-diameter drilling includes: an outer tube 1, with an upper connector 11 coaxially fixed above it. The upper connector 11 has a threaded groove for connecting an external drilling tool (not shown in the figure). The external drilling tool can continuously provide rotary drilling power. A conversion impact mechanism 2 is provided inside the outer tube 1, and a drill bit reamer 3 is provided inside the outer tube 1. The drill bit reamer 3 can perform high-frequency impact drilling under the downward air pressure of the conversion impact mechanism 2. After reaching the drilling depth, it radially expands the hole and impacts the hole under the upward air pressure of the conversion impact mechanism 2. Compared with the traditional air down-the-hole hammer, it has high hole-forming drilling efficiency, reduces the need for workers to change and adjust tools, reduces working time and labor costs, and has less wear at the end of the drill bit reamer.

[0034] In this embodiment, the conversion impact mechanism 2 includes:

[0035] The check valve seat 21 is fixed inside the outer tube 1 with the same center. An airflow channel is provided in the center of the check valve seat 21.

[0036] Piston cylinder 22 is fixed inside the outer tube and located below check valve seat 21. The lower end of the airflow passage is connected to piston cylinder 22.

[0037] The piston column 23 is sealed and slidably disposed inside the piston cylinder 22, and a buffer spring 24 is sleeved on the piston column 23; the airflow passage in the check valve seat can push the piston column vertically downward (the bypass passage is in a clear state).

[0038] The clip 25 is fixed inside the outer tube 1 and located below the piston cylinder 22. One end of the piston column 23 is slidably connected to the clip 25. A limit guide sleeve 26 is provided inside the outer tube 1 below the clip 25.

[0039] The bypass channel 27 has an opening on the side wall of the outer pipe 1. The check valve seat 21 has a lateral channel. The lateral channel is sealed and connected to the bypass channel 27. The lower end of the bypass channel 27 is connected to the piston cylinder 22. The bypass channel can push the piston column vertically upward with air pressure (the airflow channel is in a clear state).

[0040] The L-shaped inner tube 28 has one end inserted into the airflow passage of the check valve seat 21 and is connected to the lateral passage.

[0041] The upper positioning spring 29 is located inside the piston cylinder 22 and above the piston rod 23.

[0042] In a preferred embodiment, both the airflow channel and the L-shaped inner tube 28 are subjected to high-frequency air extraction and exhaust via an external air pressure pump, thereby enabling the piston column to reciprocate vertically upward or downward.

[0043] In this embodiment, the drill bit reamer 3 includes:

[0044] An inner sleeve 31 is disposed inside the outer tube 1, and a drill shaft 32 is slidably disposed inside the inner sleeve 31. One end of the drill shaft is connected to the piston column in the conversion impact mechanism.

[0045] Drill bit 34 is fixed below drill spindle 32;

[0046] Spring expansion coil 33 is set in inner sleeve 31 and sleeved on the outside of drill shaft 32;

[0047] The positioning shaft tube 35 is slidably mounted on the outer tube 1. A control ring seat 36 is fixed inside the positioning shaft tube 35. The lower end of the positioning shaft tube 35 is connected to the drill bit 34.

[0048] Radial device 4 is fixed between positioning shaft tube 35 and drill bit 34;

[0049] The reinforcing rods are circumferentially distributed inside the positioning shaft tube 35. The two ends of the reinforcing rods are respectively connected to the control ring seat 36 and the radial device 4. The radial device can perform synchronous impact movement with the drill bit.

[0050] In this embodiment, the radial device 4 includes:

[0051] The shaft disk 41 has multiple mounting grooves evenly distributed on its circumferential sidewall;

[0052] The expansion block 43 is slidably disposed in each of the mounting slots, and a sealing cavity 44 is provided in each mounting slot of the shaft disk 41;

[0053] The airflow annular chamber 42 is located above the shaft disk 41 and is connected to each of the sealing cavities 44. A shaft plug is slidably disposed in the sealing cavity 44. The shaft plug is connected to the expanding block 43. That is to say, the control ring seat can supply and exhaust air to the airflow annular chamber through the inner section tube, thereby driving each expanding block to slide radially out of the shaft disk. This allows for hole expansion and crushing after the air down-the-hole hammer reaches the drilling depth, and effective crushing of the rock wall is achieved under the high-frequency impact in the vertical direction.

[0054] In this embodiment, the cross-section of the expansion block 43 is a right-angled trapezoidal structure.

[0055] In a preferred embodiment, the shaft disk 41 is further provided with a plurality of breaking teeth 45. A double-headed telescopic support rod 46 is rotatably connected inside the shaft disk 41. The two ends of the double-headed telescopic support rod 46 are respectively connected to the expanding block 43 and the breaking teeth 45. Especially when the expanding block is in the retracted state, the breaking teeth extend out of the shaft disk. At this time, during the initial drilling, the breaking teeth can contact and break the rock wall, so that the inner wall of the well is structurally damaged, which facilitates the subsequent hole enlargement and shaping.

[0056] Specifically, in large-diameter drilling, the external drill bit can drive the air down-the-hole hammer to rotate. At this time, the switching impact mechanism drives the drill bit reamer to perform downward high-frequency impact drilling (the reamer is in the inward state). After reaching the specified drilling depth (non-engineering drilling depth), each reamer in the radial device slides radially out of the shaft disk. At this time, the impact mechanism drives the drill bit reamer to perform upward high-frequency impact reaming, thereby improving drilling efficiency, reducing drilling difficulty, and extending the service life of the drill bit.

[0057] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A large-diameter air down-the-hole hammer for drilling, characterized in that: It includes: The outer tube (1) has an upper connector (11) fixed coaxially above it. The upper connector (11) has a threaded slot for connecting an external drilling tool. The outer tube (1) has a conversion impact mechanism (2) and a drill bit reamer (3) inside. The drill bit reamer (3) can perform high-frequency impact drilling under the downward air pressure of the conversion impact mechanism (2). After reaching the drilling depth, it radially expands the hole and performs impact reaming under the upward air pressure of the conversion impact mechanism (2). The conversion impact mechanism (2) includes: The check valve seat (21) is fixed in the outer tube (1) with the same center. An airflow channel is provided in the center of the check valve seat (21). The piston cylinder (22) is fixed inside the outer tube and located below the check valve seat (21). The lower end of the airflow passage is connected to the piston cylinder (22). A piston rod (23) is slidably disposed inside the piston cylinder (22), and a buffer spring (24) is sleeved on the piston rod (23); The drill bit reamer (3) includes: An inner sleeve (31) is provided inside the outer tube (1), and a drill shaft (32) is slidably provided inside the inner sleeve (31). One end of the drill shaft (32) is connected to the piston column (23) in the conversion impact mechanism (2). The drill bit (34) is fixed below the drill shaft (32); A spring expansion ring (33) is set in the inner sleeve (31) and sleeved on the outside of the drill shaft (32); The positioning shaft tube (35) is slidably mounted on the outer tube (1). A control ring seat (36) is fixed inside the positioning shaft tube (35). The lower end of the positioning shaft tube (35) is connected to the drill bit (34). Radial device (4) is fixed between the positioning shaft tube (35) and the drill bit (34); The reinforcing rods are circumferentially distributed inside the positioning shaft tube (35), and the two ends of the reinforcing rods are respectively connected to the control ring seat (36) and the radial device (4); The radial device (4) includes: The shaft disk (41) has multiple mounting grooves evenly distributed on its circumferential sidewall; The expansion block (43) is slidably disposed in each of the mounting slots, and a sealing cavity (44) is provided in each mounting slot in the shaft disk (41); An airflow annular chamber (42) is disposed above the shaft disk (41) and is connected to each of the sealing cavities (44). A shaft plug is slidably disposed in the sealing cavity (44), and the shaft plug is connected to the expansion block (43). The shaft disk (41) is also provided with a plurality of breaking teeth (45), and a double-headed telescopic support rod (46) is rotatably connected inside the shaft disk (41). The two ends of the double-headed telescopic support rod (46) are respectively connected to the expansion block (43) and the breaking teeth (45). In large-diameter drilling, the external drill can drive the air down-the-hole hammer to rotate. At this time, the conversion impact mechanism (2) drives the drill bit reamer (3) to perform downward high-frequency impact drilling. The reamer (43) is in the inward state. After reaching the specified drilling depth, each reamer (43) in the radial device (4) slides out of the shaft disk (41) radially. At this time, the conversion impact mechanism (2) drives the drill bit reamer (3) to perform upward high-frequency impact reaming.

2. The air down-the-hole hammer for large-diameter drilling according to claim 1, characterized in that: The conversion impact mechanism (2) also includes: The card nest (25) is fixed inside the outer tube (1) and located below the piston cylinder (22). One end of the piston column (23) is sealed and slidably connected to the card nest (25). A limit guide sleeve (26) is provided inside the outer tube (1) below the card nest (25). The bypass channel (27) is provided on the side wall of the outer tube (1), and the check valve seat (21) is provided with a lateral channel. The lateral channel is sealed and connected to the bypass channel (27). The lower end of the bypass channel (27) is connected to the piston cylinder (22). The L-shaped inner tube (28) has one end inserted into the airflow passage of the check valve seat (21) and connected to the lateral passage. The upper positioning spring (29) is located inside the piston cylinder (22) and above the piston rod (23).

3. The air down-the-hole hammer for large-diameter drilling according to claim 2, characterized in that: Both the airflow channel and the L-shaped inner tube (28) are subjected to high-frequency air extraction and exhaust via an external air pressure pump.

4. The air down-the-hole hammer for large-diameter drilling according to claim 1, characterized in that: The cross-section of the expansion block (43) is a right-angled trapezoidal structure.

Images