A down-the-hole drill bit structure

Abstract

The application relates to a down-the-hole bit structure which comprises a bit body and a flow control assembly, an air channel and an auxiliary channel are arranged in the bit body, a powder discharge groove communicating with the air channel is arranged at the front end of the bit body, one end of the auxiliary channel communicates with the air channel, and the other end of the auxiliary channel penetrates through the side wall of the bit body and communicates with the outside; the flow control assembly comprises a mounting block, a driving assembly, a reset member and a stopper, the mounting block is fixedly arranged in the auxiliary channel, a main channel is arranged on the mounting block along the length direction of the auxiliary channel, the stopper slides in the mounting block along the length direction perpendicular to the main channel, the driving assembly and the reset member are arranged in the mounting block, the driving assembly is used for driving the stopper to move towards one side of the main channel to limit the speed, and the reset member is used for driving the stopper to move back towards the other side of the main channel. The air flow in the air channel is reduced to normal in the initial drilling period, manual pressure adjustment is not needed, the stability and drilling quality in the initial drilling period are improved, and the drilling operation efficiency is also improved.

Description

Technical Field

[0001] This invention relates to the field of down-the-hole drill bits, and in particular to a down-the-hole drill bit structure. Background Technology

[0002] In modern engineering construction fields, such as mining, tunnel excavation, and infrastructure construction, efficient and reliable drilling operations are crucial. Down-the-hole drill bits, as a key tool for achieving this goal, are widely used.

[0003] Down-the-hole (DH) drill bits are typically used in conjunction with pneumatic impactors, which utilize compressed air as the power medium to generate continuous impact loads at the bottom of the hole. The compressed air can also enter the air passages inside the DH drill bit and, through the guide structure at the drill bit's tip, be ejected as a high-speed airflow to the bottom of the hole. As the impactor continuously breaks up the rock, this high-speed airflow carries the resulting rock cuttings upwards rapidly along the annular gap between the drill bit and the hole wall, forming an efficient cuttings removal channel.

[0004] However, in the early stages of drilling, since no hole has been formed to restrict the direction of the drill bit's advance, the impact of these high-pressure gases on the drilling surface can actually affect the stability of the drill bit. Experienced operators will reduce the air pressure to improve the stability of the drill bit, and then increase the air pressure after drilling a hole. However, manual pressure adjustment is cumbersome and inefficient, and improper air pressure adjustment can still affect the drilling quality. Summary of the Invention

[0005] To improve stability during the initial drilling phase, this application provides a down-the-hole drill bit structure.

[0006] The down-the-hole drill bit structure provided in this application adopts the following technical solution:

[0007] A down-the-hole drill bit structure includes a drill bit body and a flow control component. The drill bit body has an air passage and an auxiliary passage. The front end of the drill bit body has a powder discharge groove that communicates with the air passage. One end of the auxiliary passage is connected to the air passage, and the other end of the auxiliary passage passes through the side wall of the drill bit body and communicates with the outside.

[0008] The flow control component includes a mounting block, a drive component, a reset component, and a stop block. The mounting block is fixedly installed in the auxiliary channel, and a main channel is formed on the mounting block along the length direction of the auxiliary channel. The stop block slides in the mounting block along the length direction perpendicular to the main channel. The drive component and the reset component are both disposed in the mounting block. The drive component is used to drive the stop block to move toward the main channel at a limited speed, and the reset component is used to drive the stop block to move toward the side away from the main channel to reset.

[0009] By adopting the above technical solution, in the initial stage of drilling, due to the high pressure of the compressed air entering the air passage, some of the high-pressure air will enter the flow control component through the auxiliary passage. The flow control component slowly controls the closure of the main channel inside, so in the initial stage of drilling, some high-pressure gas will enter the main channel and be discharged, thereby reducing the air pressure in the air passage. At the same time, the gas exiting from the auxiliary passage will not directly impact the drilling surface, but will be discharged. As the down-the-hole drill bit continuously impacts the drilling surface, holes will gradually be formed on the drilling surface. Under the constraint of the holes, the drill bit body can operate stably. During this process, the main channel will be slowly closed, the air pressure in the air passage will increase, and the drill bit body can restore the normal chip removal airflow in the holes, ensuring efficient chip removal. This achieves the reduction and restoration of the airflow in the air passage to normal in the initial stage of drilling without the need for cumbersome manual pressure adjustment, improving the stability and drilling quality in the initial stage of drilling, and also improving the efficiency of drilling operations.

[0010] Preferably, the drive assembly includes a pneumatic reciprocating assembly, a hinge rod, an input gear, a reduction assembly, an output gear, and a rack. A secondary channel is provided on the mounting block along the length of the auxiliary channel. The pneumatic reciprocating assembly is disposed within the secondary channel and has a reciprocating piston that moves back and forth. The reduction assembly is installed within the secondary channel, and its input and output shafts are coaxially fixed to the input and output gears, respectively. The two ends of the hinge rod are hinged to the gear plate of the input gear and the reciprocating piston, respectively. The reduction assembly is used to reduce the rotational speed of the input shaft and output it through the output shaft. One end of the rack is fixedly mounted on a stop block, and the other end of the rack is meshed with the output gear.

[0011] By adopting the above technical solution, the pneumatic reciprocating assembly uses the high-pressure air entering the auxiliary channel to drive the reciprocating piston to move back and forth. The hinge rod converts the linear reciprocating motion of the reciprocating piston into the rotational motion of the input gear. After the input gear reduces the speed through the reduction assembly, it transmits the power to the output gear. The output gear then converts the rotational motion into the linear sliding of the stop block through meshing with the rack.

[0012] Preferably, the pneumatic reciprocating assembly includes an outer cylinder, an inner cylinder, a reciprocating piston, an air distribution block, a bushing, and an end sleeve. The outer cylinder is fixedly disposed in the secondary channel. The end sleeve and the bushing are threadedly connected to both ends of the outer cylinder. The inner cylinder is installed in the outer cylinder and is secured and limited by the end sleeve. The air distribution block is installed in the inner cylinder. A gap channel is formed between the inner cylinder and the outer cylinder, and the gap channel communicates with the air inlet of the end sleeve.

[0013] The two ends of the reciprocating piston slide on the valve block and the bushing, respectively. One end of the reciprocating piston cooperates with the bushing and the outer cylinder to form a first cavity, and the other end of the reciprocating piston cooperates with the inner cylinder and the valve block to form a second cavity. During the reciprocating piston's back-and-forth movement, the gap channel switches between the first cavity and the second cavity. When the gap channel is connected to the second cavity, the reciprocating piston disengages from the valve block, and the inner channel of the reciprocating piston is connected to the second cavity.

[0014] By adopting the above technical solution, in the intake stage: gas enters the clearance channel from the intake port of the end sleeve. Initially, the clearance channel connects to the first chamber, and high-pressure gas enters the first chamber, pushing the reciprocating piston towards the second chamber. During the movement: under the gas pressure in the first chamber, the reciprocating piston slides along the valve block. When the reciprocating piston moves to a certain position, the clearance fit between the reciprocating piston and the inner and outer cylinder blocks disconnects the clearance channel from the first chamber, and it begins to connect with the second chamber. In the switching stage: after the clearance channel connects with the second chamber, high-pressure gas enters the second chamber. At this time, under the gas pressure in the second chamber, the reciprocating piston gradually moves towards the first chamber until it detaches from the valve block. The internal channel of the reciprocating piston connects with the second chamber, and some of the gas in the second chamber is discharged through the internal channel of the reciprocating piston. In the return stage: as the piston moves towards the first chamber, the gas in the second chamber is gradually discharged. When the piston moves to a certain position, the valve distribution structure changes again, and the clearance channel connects with the first chamber again, repeating the intake stage process, causing the piston to move towards the second chamber again. Cyclic operation: This process repeats continuously, with the gap channel constantly switching and connecting between the first and second chambers, driving the reciprocating piston to move back and forth on the gas distribution block, thus enabling the continuous operation of the pneumatic reciprocating assembly and converting the pressure energy of the gas into the mechanical energy of the piston.

[0015] Preferably, the reduction assembly includes a multi-stage meshing reduction gear set.

[0016] By adopting the above technical solution, the reduction ratio can be precisely designed according to actual needs, thereby effectively reducing the input shaft speed.

[0017] Preferably, there are at least two auxiliary channels, which are evenly distributed around the axis of the drill bit body. The auxiliary channels are inclined, with the end of the auxiliary channel away from the air passage inclined toward the side opposite to the direction of the drill bit's advance.

[0018] By adopting the above technical solution, the high-pressure air entering the auxiliary channel will be affected by the tilt angle during the flow process and sprayed out in the tilt direction, which will exert a reaction force on the drill bit body and improve the stability of the drill bit body in the initial stage of drilling.

[0019] Preferably, the reset component includes a side block and a first spring. The side block is fixedly mounted on the rack. A side groove is formed in the mounting block along the moving direction of the rack. The two ends of the first spring abut against the side block and the end wall of the side groove, respectively.

[0020] By adopting the above technical solution, the elastic force of the first spring can push the rack to reset, as well as the speed reduction mechanism and the pneumatic reciprocating assembly, when the drill bit is not in working state, thereby driving the stop block to move and reopening the main channel; when the drill bit is in working state, the elastic force of the first spring is less than the force of the airflow driving the pneumatic reciprocating assembly, thereby enabling the flow control assembly to operate normally and the main channel to be slowly closed.

[0021] Preferably, the reset component includes a side block, a first spring, a second spring, a sleeve rod, a limiting block, and a lever. The side block is fixedly mounted on the rack. A side groove is formed in the mounting block along the moving direction of the rack. The two ends of the first spring abut against the side block and the end wall of the side groove, respectively.

[0022] The output shaft of the deceleration assembly has a key block on its side wall. The sleeve has a keyway for sliding between the output shaft and the key block. The output shaft and the key block slide in the keyway along the axial direction. The limiting block is fixed to the sleeve by screws. The limiting block is located on the path of the key block moving away from the sleeve. The two ends of the second spring abut against the sleeve and the output shaft of the deceleration assembly, respectively. The second spring is used to drive the output gear to move to mesh with the rack. One end of the lever is fixed to the sleeve, and the other end of the lever extends to the opening of the secondary channel.

[0023] By adopting the above technical solution, when the drill bit is in working condition, the second spring drives the output gear to maintain meshing with the rack, ensuring that the drive assembly can normally drive the stop block to move through gear transmission, thereby realizing the closing process of the main channel; when the drill bit is not in working condition and a new hole needs to be drilled, the operator can manually move the lever to make the sleeve drive the output gear to disengage from the rack, at which time the first spring can quickly drive the rack and the stop block to reset, and the main channel is closed.

[0024] The main technical effects of this invention are reflected in the following aspects:

[0025] 1. In the initial stage of drilling, due to the high pressure of the compressed air entering the air passage, some of the high-pressure air will enter the flow control component through the auxiliary channel. During this process, the flow control component slowly controls the closure of the main channel inside, increasing the air pressure in the air passage. The drill bit body can restore the normal airflow for chip removal in the hole, ensuring efficient chip removal. This invention achieves the reduction and restoration of the airflow in the air passage to normal in the initial stage of drilling without the need for tedious manual pressure adjustment, improving the stability and drilling quality in the initial stage of drilling, and also improving the efficiency of drilling operations.

[0026] 2. The pneumatic reciprocating assembly of the present invention uses high-pressure air entering the auxiliary channel to drive the reciprocating piston to move back and forth. The hinge rod converts the linear reciprocating motion of the reciprocating piston into the rotational motion of the input gear. After the speed of the input gear is reduced by the speed reduction assembly, the power is transmitted to the output gear. The output gear then converts the rotational motion into the linear sliding of the stop block through meshing with the rack. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0028] Figure 2 It is along Figure 1 A cross-sectional view along line AA in the middle.

[0029] Figure 3 This is a schematic diagram of the flow control component in Embodiment 1 of this application.

[0030] Figure 4 This is a schematic diagram of the internal structure of the flow control component in Embodiment 1 of this application.

[0031] Figure 5 This is a cross-sectional view of the pneumatic reciprocating component of Embodiment 1 of this application.

[0032] Figure 6 This is a partial structural schematic diagram of the driving component in Embodiment 1 of this application.

[0033] Figure 7 This is a schematic diagram of the internal structure of the deceleration component in Embodiment 1 of this application.

[0034] Figure 8 This is a schematic diagram of the structure of the reset component in Embodiment 1 of this application.

[0035] Figure 9 This is a schematic diagram of the flow control component in Embodiment 2 of this application.

[0036] Figure 10 This is a partial cross-sectional view of the reset component according to Embodiment 2 of this application.

[0037] Explanation of reference numerals in the attached drawings: 1. Drill bit body; 12. Air passage; 13. Auxiliary passage; 141. Slot; 142. Insert block; 15. Powder discharge trough; 2. Flow control assembly; 21. Mounting block; 211. Semi-cylindrical block; 22. Stop block; 23. Slide groove; 24. Side groove; 25. Main channel; 26. Secondary channel; 3. Pneumatic reciprocating assembly; 31. Outer cylinder; 32. Inner cylinder; 33. Reciprocating piston; 34. Air distribution block; 35. Bushing; 36. End sleeve; 3 7. First cavity; 38. Second cavity; 39. Clearance channel; 41. Hinge rod; 42. Input gear; 43. Reduction assembly; 431. Outer shell; 432. Half shell; 433. Mounting wing; 434. Input shaft; 435. Output shaft; 44. Output gear; 45. Rack; 5. Reset component; 51. Side block; 52. First spring; 61. Second spring; 62. Sleeve rod; 63. Limiting block; 64. Lever; 65. Key block; 66. Keyway. Detailed Implementation

[0038] The following is in conjunction with the appendix Figures 1-10 This application will be described in further detail to make the technical solution of this application easier to understand and master.

[0039] This application discloses a down-the-hole drill bit structure. Example 1:

[0040] Reference Figure 1 and Figure 2 The down-the-hole drill bit structure of this embodiment includes a drill bit body 1 and a flow control component 2. The drill bit body 1 has an air passage 12 and an auxiliary passage 13. The front end of the drill bit body 1 has a powder discharge groove 15 that connects to the air passage 12. One end of the auxiliary passage 13 connects to the air passage 12, and the other end of the auxiliary passage 13 passes through the side wall of the drill bit body 1 and connects to the outside.

[0041] Reference Figures 1-4The flow control component 2 includes a mounting block 21, a drive component, a reset component 5, and a stop block 22. The mounting block 21 is fixedly installed inside the auxiliary channel 13. The mounting block 21 is composed of two semi-cylindrical blocks 211 spliced ​​together. One semi-cylindrical block 211 is provided with an insert 142, and the other semi-cylindrical block 211 is provided with a slot 141 for insertion and mating. The outer wall of the mounting block 21 and the inner wall of the auxiliary channel 13 both have a stepped surface. The end of the mounting block 21 is provided with a threaded groove, and the end with the threaded groove is threaded into the auxiliary channel 13. The stepped surface on the mounting block 21 can abut against the stepped surface of the auxiliary channel 13. The mounting block 21 has a main channel 25 along the length of the auxiliary channel 13. One of the semi-cylindrical blocks 211 has a groove 23 for the stop block 22 to slide. The stop block 22 slides in the groove 23 along the length of the main channel 25. The drive assembly and the reset component 5 are both located in the mounting block 21. The drive assembly is used to drive the stop block 22 to move toward the main channel 25 at a limited speed. The reset component 5 is used to drive the stop block 22 to move away from the main channel 25 and reset it.

[0042] Reference Figures 1-4 In the initial stage of drilling, due to the high pressure of the compressed air entering the air passage 12, some of the high-pressure air will enter the flow control component 2 through the auxiliary passage 13. The flow control component 2 slowly controls the closure of the main passage 25 inside. Therefore, in the initial stage of drilling, some high-pressure gas will enter the main passage 25 and be discharged, thereby reducing the air pressure in the air passage 12. At the same time, the gas exiting from the auxiliary passage 13 will not directly impact the drilling surface, but will be discharged. As the down-the-hole drill bit continuously impacts the drilling surface, holes will gradually be formed on the drilling surface. Under the constraint of the holes, the drill bit body 1 can operate stably. During this process, the main passage 25 will be slowly closed, the air pressure in the air passage 12 will increase, and the drill bit body 1 can restore the normal chip removal airflow in the holes, ensuring efficient chip removal. This achieves the reduction and restoration of the airflow in the air passage 12 to normal in the initial stage of drilling without the need for cumbersome manual pressure adjustment, improving the stability and drilling quality in the initial stage of drilling, and also improving the efficiency of drilling operations.

[0043] Reference Figures 1-4 The standard speed is the distance the stop 22 moves divided by the time it takes for the down-the-hole drill bit to impact the borehole surface and form a hole under normal conditions. Therefore, the limited speed must be less than the standard speed.

[0044] Reference Figures 4-6The drive assembly includes a pneumatic reciprocating assembly 3, a hinge rod 41, an input gear 42, a reduction assembly 43, an output gear 44, and a rack 45. A secondary channel 26 is provided on the mounting block 21 along the length of the auxiliary channel 13. The pneumatic reciprocating assembly 3 is disposed in the secondary channel 26 and has a reciprocating piston 33 that moves back and forth. The reduction assembly 43 is installed in the secondary channel 26. The input shaft 434 and the output shaft 435 of the reduction assembly 43 are coaxially fixed on the input gear 42 and the output gear 44, respectively. The two ends of the hinge rod 41 are respectively hinged to the gear plate of the input gear 42 and the reciprocating piston 33. The reduction assembly 43 is used to reduce the speed of the input shaft 434 and output it through the output shaft 435. One end of the rack 45 is fixedly disposed on the stop block 22, and the other end of the rack 45 is meshed with the output gear 44.

[0045] Reference Figures 4-6 The pneumatic reciprocating assembly 3 uses the high-pressure air entering the auxiliary channel 13 to drive the reciprocating piston 33 to move back and forth. The hinge rod 41 converts the linear reciprocating motion of the reciprocating piston 33 into the rotational motion of the input gear 42. After the input gear 42 reduces its speed through the reduction assembly 43, it transmits the power to the output gear 44. The output gear 44 then converts the rotational motion into the linear sliding motion of the stop block 22 through meshing with the rack 45.

[0046] Reference Figure 4 and Figure 5 The pneumatic reciprocating assembly 3 includes an outer cylinder 31, an inner cylinder 32, a reciprocating piston 33, an air distribution block 34, a bushing 35, and an end sleeve 36. The outer cylinder 31 is fixedly installed in the secondary channel 26. The end sleeve 36 and the bushing 35 are threaded to both ends of the outer cylinder 31, respectively. After the pneumatic reciprocating assembly 3 is installed, the end sleeve 36 abuts against the end face of the mounting block 21. The inner cylinder 32 is installed inside the outer cylinder 31 and is secured and limited by the end sleeve 36. The air distribution block 34 is installed inside the inner cylinder 32. A clearance channel 39 is formed between the inner cylinder 32 and the outer cylinder 31, and the clearance channel 39 communicates with the air inlet of the end sleeve 36.

[0047] Reference Figure 4 and Figure 5 The two ends of the reciprocating piston 33 slide on the valve block 34 and the bushing 35 respectively. One end of the reciprocating piston 33 cooperates with the bushing 35 and the outer cylinder 31 to form a first cavity 37. The other end of the reciprocating piston 33 cooperates with the inner cylinder 32 and the valve block 34 to form a second cavity 38. During the reciprocating piston 33's back and forth movement, the gap channel 39 switches between the first cavity 37 and the second cavity 38. When the gap channel 39 is connected to the second cavity 38, the reciprocating piston 33 disengages from the valve block 34, and the inner channel of the reciprocating piston 33 is connected to the second cavity 38.

[0048] Reference Figure 4 and Figure 5In the intake stage: Gas enters the gap passage 39 from the intake port of the end sleeve 36. In the initial state, the gap passage 39 is first connected to the first chamber 37. High-pressure gas enters the first chamber 37 and pushes the reciprocating piston 33 towards the second chamber 38. During the movement: Under the gas pressure in the first chamber 37, the reciprocating piston 33 slides along the valve block 34. When the reciprocating piston 33 moves to a certain position, the clearance fit between the reciprocating piston 33 and the inner cylinder 32 and outer cylinder 31 causes the gap passage 39 to disconnect from the first chamber 37 and begin to connect with the second chamber 38. In the switching stage: After the gap passage 39 connects with the second chamber 38, high-pressure gas enters the second chamber 38. At this time, under the gas pressure in the second chamber 38, the reciprocating piston 33 gradually moves towards the first chamber 37 until it separates from the valve block 34. The inner channel of the reciprocating piston 33 connects with the second chamber 38, and part of the gas in the second chamber 38 is discharged through the inner channel of the reciprocating piston 33. Return phase: As the piston moves towards the first chamber 37, the gas in the second chamber 38 is gradually expelled. When the piston reaches a certain position, the gas distribution structure changes again, and the gap passage 39 reconnects with the first chamber 37, repeating the intake phase process, causing the piston to move towards the second chamber 38 again. Cyclic operation: This process repeats continuously, with the gap passage 39 constantly switching between the first chamber 37 and the second chamber 38, driving the reciprocating piston 33 to reciprocate on the gas distribution block 34, realizing the continuous operation of the pneumatic reciprocating assembly 3, and converting the pressure energy of the gas into the mechanical energy of the piston.

[0049] Reference Figure 4 , Figure 6 and Figure 7 The reduction assembly 43 includes a housing 431 and an internal multi-stage meshing reduction gear set. The reduction ratio can be precisely designed according to actual needs to effectively reduce the speed of the input shaft 434. The output shaft 435 of the multi-stage meshing reduction gear set extends from the housing 431 on the same side as the input shaft 434. The housing 431 is composed of two half-shells 432 bolted together. Each half-shell 432 has a mounting wing 433, and a receiving groove is formed on the secondary channel 26 for the housing 431 to be accommodated. The mounting wing 433 is fixed in the receiving groove with screws.

[0050] Reference Figure 2 There are at least two auxiliary channels 13, which are evenly distributed around the axis of the drill bit body 1. The auxiliary channels 13 are inclined, with the end of the auxiliary channel 13 away from the air passage 12 inclined in the opposite direction of the drill bit's advance. Each auxiliary channel 13 is equipped with a flow control component 2.

[0051] Reference Figure 2 The high-pressure air entering the auxiliary channel 13 will be affected by the tilt angle during the flow process and sprayed out in the tilt direction, which will have a reaction force on the drill bit body 1 and improve the stability of the drill bit body 1 in the initial stage of drilling.

[0052] Reference Figure 4 and Figure 8 The reset component 5 includes a side block 51 and a first spring 52. The side block 51 is fixedly mounted on the rack 45. A side groove 24 is provided in the semi-cylindrical block 211 where the slide groove 23 is located, along the moving direction of the rack 45. The side groove 24 is connected to the slide groove 23. The side block 51 slides in the side groove 24. The two ends of the first spring 52 abut against the side block 51 and the end wall of the side groove 24, respectively.

[0053] Reference Figure 4 and Figure 8 When the drill bit is not in operation, the elastic force of the first spring 52 can push the rack 45 to reset, as well as the deceleration mechanism and the pneumatic reciprocating assembly 3, thereby driving the stop block 22 to move and reopen the main channel 25. When the drill bit is in operation, the elastic force of the first spring 52 is less than the force of the airflow driving the pneumatic reciprocating assembly 3, so that the flow control assembly 2 can operate normally and the main channel 25 is slowly closed. Example 2:

[0054] Reference Figures 8-10 The difference between Embodiment 2 and Embodiment 1 is that the reset component 5 includes a side block 51, a first spring 52, a second spring 61, a sleeve rod 62, a limiting block 63, and a lever 64. The side block 51 is fixedly mounted on the rack 45. A side groove 24 is provided in the mounting block 21 along the moving direction of the rack 45. The two ends of the first spring 52 abut against the side block 51 and the end wall of the side groove 24, respectively.

[0055] Reference Figures 8-10 A key block 65 is provided on the side wall of the output shaft 435 of the reduction assembly 43. A keyway 66 is provided in the sleeve rod 62 for the output shaft 435 and the key block 65 to slide. The output shaft 435 and the key block 65 of the reduction assembly 43 slide in the keyway 66 along the axial direction. The limiting block 63 is fixed to the sleeve rod 62 by screws. The limiting block 63 is located on the path of the key block 65 moving away from the sleeve rod 62. The two ends of the second spring 61 abut against the sleeve rod 62 and the output shaft 435 of the reduction assembly 43, respectively. The second spring 61 is used to drive the output gear 44 to move to mesh with the rack 45. One end of the lever 64 is fixed to the sleeve rod 62, and the other end of the lever 64 extends to the opening of the secondary channel 26.

[0056] Reference Figures 8-10When the drill bit is in working condition, the second spring 61 drives the output gear 44 to maintain engagement with the rack 45, ensuring that the drive assembly can normally drive the stop block 22 to move through gear transmission, thereby realizing the closing process of the main channel 25. When the drill bit is not in working condition and a new hole needs to be drilled, the operator can manually move the lever 64 to make the sleeve 62 drive the output gear 44 to disengage from the rack 45. At this time, the first spring 52 can quickly drive the rack 45 and the stop block 22 to reset, and the main channel 25 is closed.

[0057] Of course, the above are just typical examples of this application. In addition, this application may have many other specific implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed in this application.

Claims

1. A down-the-hole drill bit structure, characterized in that: The drill bit body (1) includes a drill bit body (1) and a flow control assembly (2). The drill bit body (1) has an air passage (12) and an auxiliary passage (13) inside. The front end of the drill bit body (1) has a powder discharge groove (15) that connects to the air passage (12). One end of the auxiliary passage (13) connects to the air passage (12), and the other end of the auxiliary passage (13) passes through the side wall of the drill bit body (1) and connects to the outside. The flow control component (2) includes a mounting block (21), a drive component, a reset component (5), and a stop block (22). The mounting block (21) is fixedly installed in the auxiliary channel (13). A main channel (25) is provided on the mounting block (21) along the length direction of the auxiliary channel (13). The stop block (22) slides in the mounting block (21) along the length direction perpendicular to the main channel (25). The drive component and the reset component (5) are both disposed in the mounting block (21). The drive component is used to drive the stop block (22) to move toward the main channel (25) at a limited speed. The reset component (5) is used to drive the stop block (22) to move and reset toward the side away from the main channel (25).

2. The down-the-hole drill bit structure according to claim 1, characterized in that: The drive assembly includes a pneumatic reciprocating assembly (3), a hinge rod (41), an input gear (42), a reduction assembly (43), an output gear (44), and a rack (45). A secondary channel (26) is provided on the mounting block (21) along the length of the auxiliary channel (13). The pneumatic reciprocating assembly (3) is located within the secondary channel (26). The pneumatic reciprocating assembly (3) has a reciprocating piston (33) that moves back and forth. The reduction assembly (43) is installed within the secondary channel (26). The input shaft (434) and output shaft (435) are coaxially fixed on the input gear (42) and output gear (44), respectively. The two ends of the hinge rod (41) are respectively hinged on the gear plate of the input gear (42) and the reciprocating piston (33). The speed reduction assembly (43) is used to reduce the speed of the input shaft (434) and output it through the output shaft (435). One end of the rack (45) is fixed on the stop block (22), and the other end of the rack (45) is meshed with the output gear (44).

3. The down-the-hole drill bit structure according to claim 2, characterized in that: The pneumatic reciprocating assembly (3) includes an outer cylinder (31), an inner cylinder (32), a reciprocating piston (33), an air distribution block (34), a bushing (35), and an end sleeve (36). The outer cylinder (31) is fixedly installed in the secondary channel (26). The end sleeve (36) and the bushing (35) are respectively threaded to the two ends of the outer cylinder (31). The inner cylinder (32) is installed in the outer cylinder (31) and is pressed and limited by the end sleeve (36). The air distribution block (34) is installed in the inner cylinder (32). A gap channel (39) is formed between the inner cylinder (32) and the outer cylinder (31). The gap channel (39) is connected to the air inlet of the end sleeve (36). The two ends of the reciprocating piston (33) slide on the valve block (34) and the bushing (35) respectively. One end of the reciprocating piston (33) cooperates with the bushing (35) and the outer cylinder (31) to form a first cavity (37). The other end of the reciprocating piston (33) cooperates with the inner cylinder (32) and the valve block (34) to form a second cavity (38). During the reciprocating piston (33) moving back and forth, the gap channel (39) switches between the first cavity (37) and the second cavity (38). When the gap channel (39) is connected to the second cavity (38), the reciprocating piston (33) disengages from the valve block (34), and the internal channel of the reciprocating piston (33) is connected to the second cavity (38).

4. The down-the-hole drill bit structure according to claim 2, characterized in that: The reduction assembly (43) includes a multi-stage meshing reduction gear set.

5. The down-the-hole drill bit structure according to claim 1, characterized in that: There are at least two auxiliary channels (13), and multiple auxiliary channels (13) are evenly distributed around the axis of the drill bit body (1). The auxiliary channels (13) are inclined, and the end of the auxiliary channel (13) away from the air passage (12) is inclined toward the side opposite to the direction of the drill bit's advance.

6. The down-the-hole drill bit structure according to claim 2, characterized in that: The reset component (5) includes a side block (51) and a first spring (52). The side block (51) is fixedly mounted on the rack (45). The mounting block (21) has a side groove (24) in the moving direction of the rack (45). The two ends of the first spring (52) abut against the side block (51) and the end wall of the side groove (24), respectively.

7. The down-the-hole drill bit structure according to claim 2, characterized in that: The reset component (5) includes a side block (51), a first spring (52), a second spring (61), a sleeve (62), a limiting block (63), and a lever (64). The side block (51) is fixedly mounted on the rack (45). The mounting block (21) has a side groove (24) in the moving direction of the rack (45). The two ends of the first spring (52) abut against the side block (51) and the end wall of the side groove (24), respectively. The output shaft (435) of the deceleration assembly (43) is provided with a key block (65) on its side wall. The sleeve (62) is provided with a keyway (66) for sliding between the output shaft (435) and the key block (65). The output shaft (435) and the key block (65) of the deceleration assembly (43) slide in the keyway (66) along the axial direction. The limiting block (63) is fixed to the sleeve (62) by screws. The limiting block (63) is located on the path of the key block (65) moving away from the sleeve (62). The two ends of the second spring (61) abut against the sleeve (62) and the output shaft (435) of the deceleration assembly (43) respectively. The second spring (61) is used to drive the output gear (44) to move to mesh with the rack (45). One end of the lever (64) is fixed to the sleeve (62), and the other end of the lever (64) extends to the opening of the secondary channel (26).

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