A cluster type roof bolter

Abstract

The application belongs to the technical field of drilling equipment, and discloses a cluster type down-the-hole hammer front guide structure, which comprises a cluster body, a central pipe for transmitting torque and rotating speed and serving as a residue discharge channel; a double-wall short joint is arranged on the outer side of the top of the central pipe and used for connecting a double-wall drill rod; an air chamber upper cover plate, an air chamber peripheral cylinder, an air chamber lower cover plate, an intermediate plate, a front joint positioning plate and a bottom lip plate are sequentially arranged below the double-wall short joint; and the air chamber upper cover plate, the air chamber lower cover plate, the intermediate plate, the front joint positioning plate and the bottom lip plate are sequentially sleeved on the outer side of the central pipe to form the cluster body; the large-diameter cluster type pneumatic reverse circulation down-the-hole hammer reamer bit solves the problems of residue discharge difficulty and low drilling efficiency of the conventional reamer bit; the cluster type down-the-hole hammer is combined with high-pressure air driving, the crushing efficiency is significantly improved, and the drilling efficiency is improved by more than 10 times compared with the conventional positive circulation cluster type pneumatic down-the-hole hammer reamer bit.

Description

Technical Field

[0001] This invention belongs to the field of drilling equipment technology, specifically a cluster-type down-the-hole hammer front guide structure. Background Technology

[0002] In mining engineering, large-diameter reverse drilling technology is widely used in ventilation shafts, ore passes, and other projects. Traditional reaming drill bits, which use roller cone or rotary cutter bits, suffer from problems such as low drilling efficiency and difficulty in removing cuttings. This is especially true in complex formations such as conglomerate, where large rock particles are difficult to remove and often require manual retrieval, severely impacting construction progress.

[0003] The cluster down-the-hole hammer is a large-diameter impact rock drilling bit that integrates an impactor. In the existing technology, although there is reverse circulation down-the-hole hammer technology, for large-diameter (diameter greater than 2 meters) reaming drilling, there is still a problem that large rock cuttings are easy to get stuck between the drill bit and the hole wall, causing the drill bit to get stuck. As a result, the rock cuttings cannot be discharged in time, making it difficult to realize continuous cuttings removal drilling technology.

[0004] Therefore, it is necessary to design a clustered down-the-hole hammer pre-guide structure to improve the above problems. Summary of the Invention

[0005] To address the problems mentioned in the background section, the present invention provides a clustered down-the-hole hammer front guide structure.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a clustered down-the-hole hammer front guide structure, comprising a cluster body, including a central tube for transmitting torque and rotational speed, and serving as a slag discharge channel; a double-walled short connector is sleeved on the outer side of the top of the central tube for connecting a double-walled drill rod; below the double-walled short connector, a chamber upper cover plate, a chamber outer casing, a chamber lower cover plate, an intermediate plate, a front connector positioning plate, and a bottom lip plate are sequentially arranged, and the chamber upper cover plate, chamber lower cover plate, intermediate plate, front connector positioning plate, and bottom lip plate are sequentially sleeved on the outer side of the central tube to form the cluster body; a front guide drill bit, the bottom of the central tube is connected to the front guide drill bit, the front end of the front guide drill bit is provided with a slag inlet for receiving rock slag broken by the down-the-hole hammer, the larger rock slag is crushed by the guide drill bit cone and guided into the internal channel of the central tube; The system comprises several down-the-hole hammers, circumferentially distributed on the outside of the central tube; an air chamber, with its outer casing connected at both ends to the upper and lower cover plates; a perforated vent on the side wall near the top of the central tube, through which high-pressure air enters and is evenly distributed to each down-the-hole hammer; an anti-jamming groove, formed on the outer wall of the bundled components, allows rock cuttings falling from the borehole wall to move to the bottom and be discharged, preventing rock cuttings from accumulating on the upper part of the bundled drill bit and causing jamming or burying accidents; a distance exists between the cuttings inlet of the front guide drill bit and the bottom surface of the down-the-hole hammers to create a pressure difference, driving the rock cuttings crushed by the down-the-hole hammers to fall into the cuttings inlet and be sucked into the internal channel of the central tube, then discharged back to the ground through the central tube to achieve continuous reverse circulation cuttings discharge.

[0007] Preferably, the double-walled short connector includes an outer tube and an inner tube, the inner tube is disposed inside the outer tube, and an annular channel is provided between the inner tube and the outer tube. The outer side of the top of the central tube is connected to the inner side of the outer tube, and the inner tube is installed inside the central tube through an inner tube mounting seat. The outer side of the inner tube is provided with a sealing ring step for sealing high-pressure gas.

[0008] Preferably, the down-the-hole hammer includes a down-the-hole hammer rear connector, a down-the-hole hammer impactor, a down-the-hole hammer front connector, and a down-the-hole hammer head, which are connected in sequence along the high-pressure air output direction in the air chamber. The end of the down-the-hole hammer rear connector away from the down-the-hole hammer impactor is connected to the upper cover plate of the air chamber through a fixed connector.

[0009] Preferably, the anti-jamming groove is a semi-circular concave channel, and the outer circumference of the upper cover plate of the air chamber, the outer perimeter cylinder of the air chamber, the lower cover plate of the air chamber, the intermediate plate, the front connector positioning plate and the bottom lip plate are evenly distributed with a number of semi-circular grooves, which constitute a semi-circular concave channel.

[0010] Preferably, several semi-circular grooves are aligned in the axial direction to form a through anti-jamming groove.

[0011] Preferably, the fixing connector is a locking nut and a locking nut. One end of the down-the-hole hammer rear connector passes through the top of the air chamber upper cover plate. The other end of the down-the-hole hammer rear connector is connected to the air chamber upper cover plate by a fixing nut and a locking nut, which are used to fix the position of the air chamber and prevent it from coming off.

[0012] Preferably, a bundle body sleeve is also provided on the outside of the bundle body, the top of the bundle body sleeve is connected to the bottom of the lower cover plate of the air chamber, and the bottom of the bundle body sleeve is connected to the top of the front connector positioning plate, in order to enhance the overall rigidity of the bundle body.

[0013] Preferably, the rear joint of the down-the-hole hammer is provided with a "『"-shaped air inlet channel to introduce high-pressure air from the air chamber into the down-the-hole hammer impactor and drive the impactor piston to move at high frequency.

[0014] Preferably, the bottom of the cluster body is also connected to a front guide plate consisting of a lower positioning plate and an upper positioning plate. The lower positioning plate and the upper positioning plate are fixedly connected by a fastener, and an air groove is formed between them. The internal air passage of the down-the-hole hammer has a side groove on one side, which is connected to the air groove. The circumferential surface of the central tube has an annular groove, and a jet hole is provided downward in the annular groove, extending to the stepped surface on the front guide drill bit. The internal air passage of the down-the-hole hammer forms a passage to the jet hole through the side groove, the air groove and the annular groove.

[0015] Preferably, a bushing is provided around the outer periphery of the central tube. The bushing is located between the central hole of the front guide plate and the central tube. The bushing has air holes that connect the annular groove and the air groove. The exhaust direction of the jet orifice is at an angle of 20-30° to the horizontal plane, and the exhaust direction is radially deviated towards the center pipe.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes an innovative inverted conical design for the guide drill bit matrix to control the crushing and grinding of larger rock fragments before they enter the backfill channel, preventing blockage of large-diameter rock fragments at the inlet and within the channel. The design also modifies the thread type of the guide drill bit connection to prevent detachment accidents. Previously, the guide drill bit connection used an API thread type, which resulted in uneven stress within the guide hole, fatigue damage, and loosening of the threads, making it prone to falling into the hole. Furthermore, due to the hole's inclination, the guide drill bit experienced excessive lateral force from the formation, leading to fatigue failure and detachment. The new guide drill bit connection thread design, with its straight, fine-thread design, effectively prevents premature loosening and damage, thus preventing detachment accidents.

[0017] This invention solves the problems of difficult slag removal and low drilling efficiency of traditional reaming drill bits by using a large-diameter clustered pneumatic reverse circulation down-the-hole hammer reaming drill bit. Through the design of the reverse circulation slag removal system and anti-jamming drill groove, large-particle rock slag can be continuously discharged, avoiding manual slag removal and shortening the construction cycle. The clustered down-the-hole hammer combined with high-pressure air drive significantly improves the crushing efficiency, and the drilling efficiency is more than 10 times higher than that of traditional forward circulation clustered pneumatic down-the-hole hammer reaming drill bits.

[0018] This invention, through the design of the front guide plate, draws part of the exhaust gas from the down-the-hole hammer into the jet hole, utilizes the exhaust gas to continuously spray high-speed airflow downward through the jet hole, creates a vacuum at the drill bit slag inlet to suck the drill slag into the central tube, and further improves the slag discharge rate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the large-diameter clustered pneumatic reverse circulation down-the-hole hammer reamer drill bit of the present invention. Figure 2 This is a front view of the air chamber section provided by the present invention; Figure 3 This is a cross-sectional side view of the air chamber provided by the present invention; Figure 4 The down-the-hole hammer structure provided by this invention; Figure 5 The bottom lip plate structure provided by the present invention; Figure 6 A schematic diagram of the cross-sectional structure of the pilot drill bit provided for the invention; Figure 7 This is a bottom view of the front guide plate of the present invention; Figure 8 This is a disassembly diagram of the front guide plate of the present invention; Figure 9 This is a cross-sectional view of the front guiding structure of the present invention.

[0020] In the diagram: 1. Double-walled short connector; 2. Inner tube; 3. Anti-reverse nut; 4. Locking nut; 5. Upper cover plate of the air chamber; 6. Outer casing of the air chamber; 7. Lower cover plate of the air chamber; 8. Rear connector of the down-the-hole hammer; 9. Inner tube support seat; 10. Central tube; 11. Down-the-hole hammer impactor; 12. Intermediate plate; 13. Bundle casing; 14. Front connector of the down-the-hole hammer; 15. Front connector positioning plate; 16. Bottom lip plate; 17. Down-the-hole hammer head; 18. Front guide drill bit; 19. Slag inlet; 20. Air chamber; 21. Air inlet channel; 22. Lower positioning plate; 23. Upper positioning plate; 24. Air groove; 25. Bushing; 26. Side groove; 27. Air hole; 28. Positioning port; 29. ​​Protrusion; 30. Annular groove; 31. Jet hole; 32. Fixing insert. Detailed Implementation

[0021] 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.

[0022] like Figures 1 to 6 As shown, the present invention provides a large-diameter clustered pneumatic reverse circulation down-the-hole hammer reaming drill bit, comprising: a cluster body, including a central tube 10, used to transmit torque and rotational speed, and serving as a slag discharge channel; a double-walled short connector 1 is sleeved on the outer side of the top of the central tube 10 for connecting a double-walled drill rod; below the double-walled short connector 1, an upper cover plate 5 of the air chamber, an outer casing 6 of the air chamber, a lower cover plate 7 of the air chamber, an intermediate plate 12, a front connector positioning plate 15, and a bottom lip plate 16 are sequentially arranged; the upper cover plate 5 of the air chamber, the lower cover plate 7 of the air chamber, the intermediate plate 12, the front connector positioning plate 15, and the bottom lip plate 16 are sequentially sleeved on the outer side of the central tube 10 to form a cluster body; The front guide drill bit 18 is connected to the bottom of the central tube 10. The front end of the front guide drill bit 18 is provided with a slag inlet 19, which is used to receive the rock slag discharged through the anti-jamming drill groove and guide the rock slag into the internal channel of the central tube 10. Down-the-hole hammers, with multiple down-the-hole hammers evenly distributed circumferentially on the outer side of the central tube 10; The air chamber 20 is formed by connecting the two ends of the outer casing 6 of the air chamber to the upper cover plate 5 and the lower cover plate 7 of the air chamber respectively. A perforated vent is provided on the top side wall near the center tube 10. High-pressure air enters the air chamber 20 through the perforated vent and is evenly distributed to each downhole hammer in the air chamber. Anti-jamming slots are set on the outside of the bundled body components to discharge large rock fragments from impact crushing; there is a distance between the slag inlet 19 of the front guide drill bit 18 and the bottom surface of the down-the-hole hammer to form a pressure difference, which drives the large rock fragments discharged through the anti-jamming slots and falling into the slag inlet 19 to be sucked into the internal channel of the central tube 10, and discharged to the ground through the central tube 10 to achieve reverse circulation continuous slag discharge. It should be noted that the perforated vent on the central tube 10 is connected to the air passage of each down-the-hole hammer via the air chamber 20, which is used to distribute high-pressure air to the interior of each down-the-hole hammer, driving the piston inside to reciprocate, generating high-frequency impact energy and transmitting it to the alloy teeth at the bottom of the down-the-hole hammer, thereby efficiently breaking the rock at the bottom of the hole; multiple down-the-hole hammers are evenly distributed in a ring array outside the central tube 10, with their hammer heads 17 located at the bottom of the cluster, on a working plane close to the slag inlet 19 of the front guide drill bit 18, working together to form a hole-enlarging effect on the rock at the bottom of the hole; the anti-jamming drill groove consists of the outer casing 6 of the air chamber, the lower cover plate 7 of the air chamber, and the intermediate plate 12. The outer contours of components such as the front connector positioning plate 15 and the bottom lip plate 16 together define and form a groove structure extending longitudinally along the outer wall of the drill bit. This provides a smooth upward return channel for the large rock cuttings after crushing, effectively preventing rock cuttings from accumulating and getting stuck in the gap between the borehole wall and the drill bit annular space. Under the continuous delivery of high-pressure air and the impact of the down-the-hole hammer, the rock cuttings mixture formed at the bottom of the hole is forced into the reverse circulation channel inside the central tube 10 through the cuttings inlet 19 under the entrainment of the airflow and the aforementioned pressure difference. This achieves efficient and continuous reverse circulation of rock cuttings from the bottom of the hole to the surface, significantly improving the efficiency and hole quality of large-diameter hard rock reaming construction.

[0023] like Figure 1 As shown, the double-walled short connector 1 includes an outer tube and an inner tube 2. The inner tube 2 is set inside the outer tube, and an annular channel is provided between the inner tube 2 and the outer tube. High-pressure air enters the air chamber 20 through the annular channel and the vent hole, and is evenly distributed to each downhole hammer in the air chamber. The outer side of the top of the central tube 10 is connected to the inner side of the outer tube, and the inner tube 2 is installed inside the central tube 10 through the inner tube 2 mounting seat. The outer side of the inner tube 2 is provided with a sealing ring step for sealing high-pressure gas; It should be noted that the sealing ring step adopts a high-pressure resistant rubber O-ring design to ensure that the annular channel between the inner tube 2 and the outer tube is leak-free under high pressure conditions; the mounting base of the inner tube 2 is fixed to the inner wall of the central tube 10 by a threaded connection, which is convenient for disassembly and maintenance; at the same time, the bottom of the outer tube is provided with a flange interface for connecting to an external air supply system to ensure a stable input of high-pressure air.

[0024] like Figures 1 to 4 As shown, the down-the-hole hammer includes a down-the-hole hammer rear connector 8, a down-the-hole hammer impactor 11, a down-the-hole hammer front connector 14, and a down-the-hole hammer head 17, which are connected in sequence along the high-pressure air output direction in the air chamber 20. The end of the down-the-hole hammer rear connector 8 away from the down-the-hole hammer impactor 11 is connected to the upper cover plate 5 of the air chamber through a fixed connector. It should be noted that the down-the-hole hammer impactor 11 is equipped with a high-pressure gas-driven piston mechanism. When high-pressure air is input from the air chamber 20 through the down-the-hole hammer rear connector 8, the piston reciprocates rapidly, generating a high-frequency impact force, which is transmitted to the down-the-hole hammer head 17 through the down-the-hole hammer front connector 14. The down-the-hole hammer front connector 14 is designed with a conical transition structure to ensure efficient transmission and sealing of the impact force, while also buffering vibration. The down-the-hole hammer head 17 is inlaid with hard alloy, and its front end is equipped with a reverse circulation exhaust port, which achieves efficient crushing and reverse discharge of debris during the rock impact process. Each down-the-hole hammer is rigidly connected to the air chamber upper cover plate 5 through a fixed connector to ensure structural stability and synchronous impact effect under high pressure conditions.

[0025] like Figure 1 As shown, the anti-jamming groove is a semi-circular concave channel. The outer circumference of the air chamber upper cover plate 5, the air chamber outer perimeter cylinder 6, the air chamber lower cover plate 7, the intermediate plate 12, the front connector positioning plate 15 and the bottom lip plate 16 are evenly distributed with several semi-circular grooves, which constitute a semi-circular concave channel. like Figure 1 As shown, several semi-circular grooves are aligned in the axial direction to form a through anti-jamming groove.

[0026] It should be noted that the depth and width of these semi-circular grooves are precisely designed to form a continuous cuttings discharge path under high-pressure airflow, effectively guiding drill cuttings out circumferentially and preventing debris accumulation or blockage inside the drill bit. Simultaneously, combined with high-strength alloy steel, the groove structure possesses excellent deformation resistance and wear resistance under harsh working conditions, ensuring the cuttings discharge channel remains unobstructed during prolonged operations, thereby improving drilling efficiency and reducing maintenance requirements. Furthermore, the anti-sticking grooves are coordinated with the overall drill bit layout, optimizing airflow distribution and cuttings flow, further enhancing the continuity and stability of the raise and reaming process.

[0027] like Figure 1 and Figure 2 As shown, the fixed connectors are a fixing nut and a locking nut. One end of the down-the-hole hammer rear connector 8 passes through the top of the air chamber upper cover plate 5. The other end of the down-the-hole hammer rear connector 8 is connected to the air chamber upper cover plate 5 through the fixing nut and the locking nut, which are used to fix the position of the air chamber 20 and prevent it from coming off. like Figure 1 As shown, a bundle body sleeve 13 is also fitted on the outside of the bundle body. The top of the bundle body sleeve 13 is connected to the bottom of the air chamber lower cover plate 7, and the bottom of the bundle body sleeve 13 is connected to the top of the front connector positioning plate 15, which is used to enhance the overall rigidity of the bundle body. like Figure 1 and Figure 2 As shown, a "『"-shaped air inlet channel 21 is provided on the cross section of the rear connector 8 of the down-the-hole hammer, which is used to introduce the high-pressure air in the air chamber 20 into the down-the-hole hammer impactor 11 and drive the impactor piston to move at high frequency. It should be noted that the anti-jamming drill groove and the reverse circulation slag removal system work together to achieve efficient slag removal. The specific design is as follows: The anti-jamming drill groove is a semi-circular concave channel, which is composed of semi-circular grooves evenly distributed on the outer circumference of the air chamber upper cover plate 5, the air chamber outer outer sleeve 6, the air chamber lower cover plate 7, the intermediate plate 12, the front joint positioning plate 15, and the bottom lip plate 16. The semi-circular grooves of each component are aligned in the axial direction to form a through slag removal channel, which is used to discharge large particles of rock slag generated by impact crushing and prevent rock slag from getting stuck between the drill bit and the borehole wall. like Figure 6 As shown, there is a preset distance between the slag inlet 19 of the front guide drill bit 18 and the bottom surface of the down-the-hole hammer, which creates a pressure difference. Under the action of the pressure difference, large rock slag particles that are discharged through the anti-jamming drill groove and fall into the slag inlet 19 are sucked into the internal channel of the central tube 10 and finally discharged to the ground through the central tube 10, realizing continuous reverse circulation slag discharge.

[0028] Example 2, as Figures 7-9 As shown, the bottom of the cluster body casing 13 is also connected to a front guide plate consisting of a lower positioning plate 22 and an upper positioning plate 23. The lower positioning plate 22 and the upper positioning plate 23 are fixedly connected by a fastener, and an air groove 24 is formed between them. The internal air passage of the down-the-hole hammer is opened to one side with a 35, which is connected to the air groove 24. The circumferential surface of the central tube 10 is provided with an annular groove 30, and a jet hole 31 is provided downward in the annular groove 30, extending to the stepped surface on the front guide drill bit 18. The internal air passage of the down-the-hole hammer forms a passage to the jet hole 31 through the 35, the air groove 24 and the annular groove 30.

[0029] The front guide plate is composed of a lower positioning plate 22 and an upper positioning plate 23, which are spliced ​​together and fixed by upper and lower locking bolts. The front guide structure is fixed to the outer cylinder of the bundle by a fixing insert 32. The front guide plate is provided with guide holes distributed in the center and around the perimeter, which are used to install the front guide drill bit and the down-the-hole hammer, respectively. At the bottom end of the central tube 10, a circumferential opening 35 is provided to connect to the air groove 24. The air groove 24 is connected to the annular groove 30 and the jet hole 31. Some of the exhaust gas in the down-the-hole hammer air passage is released through the jet hole 31 on the stepped surface below the guide drill bit, so as to be close to the slag inlet 19 of the drill bit. The airflow is ejected in the form of a jet, which easily creates a strong negative pressure at the slag inlet 19, thereby sucking the slag into the central tube. The opening shape of 35 is L-shaped, and its outer vertical groove can always be connected to the air groove 24 during the down-the-hole hammer hammering process, so as to maintain the continuous entry of airflow and ensure the continuity of the jet. At the same time, it can also blow away the slag adhering to the drill bit through high-speed jets, preventing adhesion and affecting drilling efficiency.

[0030] like Figure 8 and Figure 9As shown, a bushing 25 is also provided on the outer periphery of the central tube 10. The bushing 25 is located between the central hole of the front guide plate and the central tube. An air hole 27 is provided on the bushing 25. The air hole 27 connects the annular groove 30 and the air groove 24. The exhaust direction of the jet hole 31 is at an angle of 20-30° with the horizontal plane, and the exhaust direction is radially deviated towards the central tube.

[0031] A positioning port 28 is provided on the upper outer edge of the bushing 25. Correspondingly, clamps 33 and 38 are provided around the central hole of the bushing 25. The bushing 25 serves as a component connecting the central tube, the jet hole 31, and the air groove 24, and provides auxiliary positioning for the lower end of the central tube. The exhaust direction of the jet hole 31 creates a strong vortex downwards, causing the slag to be drawn towards the center, carrying the drill cuttings into the central tube, forming a reverse circulation slag discharge.

[0032] Working principle and process: Impact crushing process: High-pressure air enters the air chamber 20 through the annular channel between the inner and outer tubes of the double-wall drill rod, through the annular channel of the double-wall short joint 1 and the flower-shaped vent hole of the central tube 10; the high-pressure air in the air chamber is distributed to each down-the-hole hammer impactor 11 through the "『"-shaped air intake channel 21 of the down-the-hole hammer rear joint 8, driving the impactor piston to impact the down-the-hole hammer head 17 at high frequency, and the hammer head crushes the rock with high-frequency vibration.

[0033] Reverse circulation slag discharge process: Large rock slag particles generated by crushing are crushed by the inverted cone of the guide drill bit, avoiding repeated crushing and clogging of the slag inlet; under the pressure difference between the slag inlet 19 and the bottom surface of the down-the-hole hammer, the rock slag is sucked into the internal channel of the central tube 10 through the slag inlet 19, and finally discharged to the ground through the central tube, realizing continuous and efficient slag discharge.

[0034] It is worth noting that this invention solves the problems of difficult slag removal and low drilling efficiency of traditional reaming drill bits. Through the design of a reverse circulation slag removal system and an anti-jamming drill groove, large-particle rock cuttings can be continuously discharged, avoiding manual slag removal and shortening the construction cycle. The clustered down-the-hole hammer combined with high-pressure air drive significantly improves the crushing efficiency, increasing the drilling efficiency by more than 10 times compared to traditional forward circulation clustered pneumatic down-the-hole hammer reaming drill bits. It is suitable for large-diameter reaming operations with a diameter greater than 2 meters, and performs particularly well in complex strata such as conglomerate, expanding the application scope of reverse circulation down-the-hole hammer technology.

[0035] The clustered down-the-hole hammer design, combined with high-pressure air drive, significantly improves crushing efficiency. Compared with traditional positive circulation clustered pneumatic down-the-hole hammer reamer, the drilling efficiency is more than 10 times higher. It is suitable for large-diameter borehole enlargement operations with a diameter greater than 2 meters, and performs particularly well in complex strata such as conglomerate, thus expanding the application scope of reverse circulation down-the-hole hammer technology.

[0036] In specific implementation, such as Figure 1As shown, the large-diameter clustered pneumatic reverse circulation down-the-hole hammer reamer of the present invention uses a central tube 10 as its core, with a double-walled drill rod connected to the top via a double-walled short connector 1, and a front guide drill bit 18 connected to the bottom. The inner tube 2 and outer tube of the double-walled short connector 1 form an annular channel, through which high-pressure air enters the air chamber 20 via the perforated vent of the central tube 10. Figure 2 , Figure 3 As shown.

[0037] High-pressure air in chamber 20 passes through the "『"-shaped air intake channel 21 of the downhole hammer rear connector 8. Figure 4 As shown, the down-the-hole hammer 11 drives the piston to impact the down-the-hole hammer head 17 at high frequency, which, in conjunction with the bottom lip plate 16, is as follows: Figure 5 The diagram illustrates how rock breaking is achieved.

[0038] Large rock fragments produced by crushing are discharged through the anti-jamming groove formed by components such as the gas chamber cover plate 5 and the gas chamber outer casing 6, and fall into the slag inlet 19 of the front guide drill bit 18. Figure 6 As shown, under the pressure difference between the slag inlet 19 and the bottom surface of the downhole hammer, the rock cuttings are sucked into the central tube 10 and eventually discharged back to the ground, completing the continuous operation of drilling and slag removal.

[0039] By designing the front guide plate, the exhaust gas from the down-the-hole hammer is led out into the jet hole 31, or high-pressure airflow is led out directly from the upper air chamber into the jet hole 31. The jet hole 31 sprays high-speed airflow downwards, creating a vacuum at the drill bit slag inlet to suck the drill slag into the central tube 10, further improving the slag discharge rate.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A clustered down-the-hole hammer pre-guide structure, characterized in that: The assembly includes a central tube (10) for transmitting torque and rotational speed and serving as a slag discharge channel; a double-walled short connector (1) is sleeved on the outer side of the top of the central tube for connecting a double-walled drill rod; below the double-walled short connector (1) are arranged sequentially an upper cover plate (5) of the air chamber, an outer casing (6) of the air chamber, a lower cover plate (7) of the air chamber, an intermediate plate (12), a front connector positioning plate (15) and a bottom lip plate (16), and the upper cover plate (5) of the air chamber, the lower cover plate (7) of the air chamber, the intermediate plate (12), the front connector positioning plate (15) and the bottom lip plate (16) are sequentially sleeved on the outer side of the central tube (10) to form the assembly; The front guide drill bit (18) is connected to the bottom of the central tube (10). The front end of the front guide drill bit (18) is provided with a slag inlet (19) for receiving rock slag discharged through the anti-jamming slot and guiding the rock slag into the internal channel of the central tube (10). Down-the-hole hammers, multiple down-the-hole hammers are evenly distributed circumferentially on the outside of the central tube (10); The air chamber (20) is formed by connecting the two ends of the outer casing (6) of the air chamber to the upper cover plate (5) and the lower cover plate (7) of the air chamber. A perforated vent is provided on the top side wall near the center tube (10). High-pressure air enters the air chamber (20) through the perforated vent and is evenly distributed to each downhole hammer in the air chamber (20). Anti-jamming groove is formed on the outer wall of the bundle body component to discharge large-particle rock debris from the borehole; there is a distance between the slag inlet (19) of the front guide drill bit (18) and the bottom surface of the down-the-hole hammer to form a pressure difference, which drives the large-particle rock debris discharged through the anti-jamming groove and falling into the slag inlet (19) to be sucked into the internal channel of the central tube (10) and discharged to the ground through the central tube (10) to achieve reverse circulation continuous slag discharge; The down-the-hole hammer includes a down-the-hole hammer rear connector (8), a down-the-hole hammer impactor (11), a down-the-hole hammer front connector (14), and a down-the-hole hammer head (17) connected in sequence along the high-pressure air output direction in the air chamber (20). The end of the down-the-hole hammer rear connector (8) away from the down-the-hole hammer impactor (11) is connected to the upper cover plate (5) of the air chamber by a fixed connector. The outside of the bundle body is also fitted with a bundle body sleeve (13). The top of the bundle body sleeve (13) is connected to the bottom of the air chamber lower cover plate (7), and the bottom of the bundle body sleeve (13) is connected to the top of the front connector positioning plate (15) to enhance the overall rigidity of the bundle body. The rear connector (8) of the downhole hammer is provided with a "『" shaped air inlet channel (21) to introduce the high-pressure air in the air chamber (20) into the downhole hammer impactor (11) and drive the impactor piston to move at high frequency. The bottom of the bundled body casing (13) is also connected to a front guide plate consisting of a lower positioning plate (22) and an upper positioning plate (23). The lower positioning plate (22) and the upper positioning plate (23) are fixed together by a fastener, and an air groove (24) is formed between them. The internal air passage of the downhole hammer is provided with a side groove (26) on one side. The side groove (26) is connected to the air groove (24). The circumferential surface of the central tube (10) is provided with an annular groove (30), and a jet hole (31) is provided downward in the annular groove (30) extending to the stepped surface above the front guide drill bit (18). The internal air passage of the downhole hammer forms a passage to the jet hole (31) through the side groove (26), the air groove (24) and the annular groove (30).

2. The clustered down-the-hole hammer pre-guide structure according to claim 1, characterized in that: The double-walled short connector (1) includes an outer tube and an inner tube (2). The inner tube (2) is disposed inside the outer tube, and an annular channel is provided between the inner tube (2) and the outer tube. The outer side of the top of the central tube (10) is connected to the inner side of the outer tube. The inner tube (2) is installed inside the central tube (10) through the inner tube (2) mounting seat. The inner tube (2) is provided with a sealing ring step on the outside for sealing high-pressure gas.

3. The clustered down-the-hole hammer pre-guide structure according to claim 1, characterized in that: The anti-jamming groove is a semi-circular concave channel. The outer circumference of the upper cover plate (5), the outer casing cylinder (6), the lower cover plate (7), the middle plate (12), the front connector positioning plate (15), and the bottom lip plate (16) of the air chamber are evenly distributed with a number of semi-circular grooves, which constitute a semi-circular concave channel.

4. The clustered down-the-hole hammer pre-guide structure according to claim 3, characterized in that: Several semi-circular grooves are aligned in the axial direction to form a through anti-jamming groove.

5. The clustered down-the-hole hammer pre-guide structure according to claim 1, characterized in that: The fixed connectors are a locking nut (4) and a backstop nut (3). One end of the downhole hammer rear connector (8) passes through the top of the air chamber upper cover plate (5). One end of the downhole hammer rear connector (8) is connected to the air chamber upper cover plate (5) by the locking nut and the backstop nut, which are used to fix the position of the air chamber (20) and prevent it from coming off.

6. The clustered down-the-hole hammer pre-guide structure according to claim 1, characterized in that: A bushing (25) is also provided on the outer periphery of the central tube (10). The bushing (25) is located between the central hole of the front guide plate and the central tube. An air hole (27) is provided on the bushing (25). The air hole (27) connects the annular groove (30) and the air groove (24). The exhaust direction of the jet hole (31) is at an angle of 20-30° with the horizontal plane, and the exhaust direction is radially deviated towards the central tube.

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