Telescopic down-the-hole hammer rotary drill rod

Abstract

This utility model discloses a telescopic down-the-hole hammer rotary drilling rod, comprising a working unit, a connecting part, a drive unit, and an air injection unit. The working unit consists of multiple coaxially nested working rod sections that can move relative to each other axially. It connects to the down-the-hole hammer and transmits torque and axial force. Its nested structure minimizes the rod's length when not in operation, allowing it to extend section by section during operation to accommodate different drilling depths. The connecting part is located at the top of the outermost working rod section, providing a rigid connection between the working unit and the drive unit. The drive unit includes a lifting actuator connected to the connecting part and a rotating support mechanism connected to the drilling rig's lifting mechanism, used to drive the lifting and rotation of the working unit. The air injection unit is located within the rotating support mechanism and extends into the working unit, supplying compressed air to the down-the-hole hammer. This drilling rod effectively solves the problems of inconvenient transportation and frequent disassembly required for traditional drilling rods in deep-hole operations, enabling continuous drilling without disassembly and improving operational efficiency.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery technology, and in particular to a telescopic down-the-hole hammer rotary drilling rod. Background Technology

[0002] Down-the-hole (DH) hammer drilling technology has been widely used in mineral exploration, hydrological drilling, and foundation engineering construction due to its efficient rock-breaking characteristics. This technology typically uses a rotary drill rod to connect the drill rig's power head on the surface to the DH hammer at the bottom of the hole. This rod is responsible for transmitting torque, axial pressure, or tension, and forms a compressed air delivery channel to drive the DH hammer.

[0003] As engineering demands extend to deeper strata, higher requirements are being placed on drill pipe length. Traditional single-section or flange-connected drill pipes significantly increase in overall length when dealing with deep boreholes, causing considerable inconvenience in transportation, on-site handling, and positioning on the drilling rig mast, and posing significant safety risks. To overcome the drawbacks of long, integral drill pipes, existing technologies have adopted a method of connecting multiple drill pipe sections sequentially via threads within the hole. However, this method has significant shortcomings: First, each connection or disconnection of drill pipe requires stopping drilling operations, resulting in cumbersome procedures, extended auxiliary time, and reduced overall drilling efficiency; second, frequent unloading operations are not only labor-intensive but also prone to wear on the threaded connections, affecting connection reliability and potentially causing borehole deviation; third, in complex strata or deep hole operations, multiple interruptions in the cycle may increase the risk of borehole instability.

[0004] Therefore, a telescopic down-the-hole hammer rotary drill rod is proposed to address the current shortcomings. Summary of the Invention

[0005] In view of this, the present invention provides a telescopic down-the-hole hammer rotary drilling rod to solve or alleviate the technical problems existing in the prior art.

[0006] The technical solution of this utility model embodiment is implemented as follows: a telescopic down-the-hole hammer rotary drilling rod, comprising:

[0007] The working unit has multiple coaxially nested working rods that can move relative to each other axially, for connection with the down-the-hole hammer;

[0008] The connecting part is located at the top of the outermost working rod.

[0009] The drive unit has a lifting actuator connected to the connecting part and a rotating support mechanism connected to the lifting actuator. The drive unit is used to connect the drilling rig lifting mechanism and realize the rotation of the working unit relative to the rotating support mechanism, as well as drive the lifting of the working unit.

[0010] An air injection unit, located within the rotating support mechanism and extending into the working unit, is used to supply compressed air to the down-the-hole hammer.

[0011] In the above embodiments, the working rod portion includes

[0012] The working rod has multiple sections, which have the same structure and gradually changing size. The working rods are coaxially nested in sequence, and any adjacent working rods slide together.

[0013] Multiple key bar pressure blocks are provided, in groups of three, and the key bar pressure blocks in each group are evenly arranged circumferentially along the outer side wall of the corresponding working rod.

[0014] The limiting blocks are provided in multiple groups of three, and the limiting blocks in each group are respectively arranged circumferentially along the bottom of the inner wall of the corresponding working rod.

[0015] The rotary drilling head is fixedly connected to the bottom end of the innermost working rod;

[0016] The key bar pressure block is provided with a limiting groove that cooperates with the limiting block. The limiting groove cooperates with the limiting block to limit the relative movement range of the working rod.

[0017] In the above embodiments, the connecting portion includes:

[0018] A fixed flange is coaxially mounted at the top of the outermost working rod.

[0019] Multiple flange stiffeners are provided, and the multiple flange stiffeners are evenly arranged around the outermost working rod. One end of each flange stiffener is connected to the fixed flange.

[0020] The rear flange is fitted onto the outermost working rod and is fixedly connected to the other end of each flange stiffener.

[0021] The shock-absorbing pad is fitted onto the outermost working rod and connected to the rear flange.

[0022] In the above embodiments, the lifting actuator includes:

[0023] The outer bearing is coaxially mounted on the fixed flange, and its outer ring is fixedly connected to the fixed flange by bolts.

[0024] The follower frame is coaxially mounted on the outer bearing and is fixedly connected to the inner ring of the outer bearing.

[0025] In the above embodiments, the rotating support mechanism includes:

[0026] A fixed connector is coaxially arranged with the follower frame;

[0027] The rotary drilling cap is coaxially mounted inside the follower frame. The upper end of the rotary drilling cap is fixedly connected to the bottom end of the fixed joint, and the lower end is engaged with the top end of the innermost working rod.

[0028] The intermediate cylinder is coaxially arranged with the fixed joint, and its bottom is threadedly connected to the fixed joint.

[0029] The upper connector is located on the intermediate cylinder, and its bottom end extends into the rotary drilling cap.

[0030] The bearing is provided in multiple ways, and the multiple bearings are sequentially sleeved on the upper joint, with the outer wall of each bearing fitting with the inner wall of the intermediate cylinder.

[0031] There are two locking nuts, which are located at the bottom of the upper connector and are threaded to the upper connector. The upper locking nut abuts against the corresponding inner ring of the bearing to fix the axial position of the bearing.

[0032] A connecting plate, rotatably connected to the upper connector, is used to connect to the drilling rig lifting mechanism;

[0033] The outer ring of the uppermost bearing abuts against the middle cylinder, and its inner ring abuts against the upper connector. The outer ring of the lowermost bearing abuts against the fixed connector, and its inner ring abuts against the locking nut.

[0034] In the above embodiments, the gas injection unit includes:

[0035] The air injection channel is vertically arranged in a "Z" shape and is set along the axis of the upper connector to introduce compressed air;

[0036] The connecting hole is located at the bottom of the outermost working rod and is connected to the air injection channel to deliver compressed air to the down-the-hole hammer.

[0037] The present invention has the following advantages due to the adoption of the above technical solution:

[0038] This invention employs a multi-section coaxial nested, relatively sliding working rod structure, which minimizes the storage length of the drill rod when not in operation, greatly facilitating transportation and on-site positioning. During operation, it can extend and lock section by section within the hole without disassembling any parts, effectively overcoming the drawbacks of traditional threaded drill rods that require frequent disassembly and reassembly, long auxiliary time, and high labor intensity, significantly improving the continuity and overall efficiency of deep hole drilling operations.

[0039] This utility model utilizes the coordinated cooperation of the key bar pressure block, the limiting block, and the limiting groove set on the working rod to not only achieve reliable and stepwise transmission of torque from the outer rod to the inner rod, ensuring the effective output of rotary drilling power to the down-the-hole hammer, but also achieve reliable locking of different extension lengths through the limiting mechanism, preventing the drill rod from accidentally retracting during drilling and ensuring the stability and control accuracy of the drilling depth.

[0040] This invention integrates the air injection channel into the rotating support mechanism and passes through the nested working rod, achieving stable and continuous delivery of compressed air to the down-the-hole hammer during drill rod rotation. The design of the lifting actuator and the rotating support mechanism effectively separates the lifting guide from the rotational motion, preventing twisting and tangling of the main winding wire rope. Furthermore, the shock-absorbing pads at the connection effectively absorb vibrations and impacts from the bottom of the hole, reducing the transmission to the upper structure of the drilling rig, thus increasing equipment lifespan and operational stability.

[0041] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of this utility model;

[0044] Figure 2 This is a schematic diagram of the structure of the present invention in use.

[0045] Figure 3 This is a side view of the structure of this utility model;

[0046] Figure 4 for Figure 3 Sectional view at point AA;

[0047] Figure 5 for Figure 4 A magnified view of a section at point B in the middle;

[0048] Figure 6 This is a schematic diagram of the working rod part in this utility model. Figure 1 ;

[0049] Figure 7 This is a schematic diagram of the working rod part in this utility model. Figure 2 .

[0050] Figure label:

[0051] 1. Working rod section; 11. Working rod; 12. Key bar pressure block; 121. Limiting groove; 13. Limiting block; 14. Rotary drilling head;

[0052] 2. Connecting parts; 21. Fixed flange; 22. Flange stiffener; 23. Rear flange; 24. Vibration damping pad;

[0053] 3. Lifting actuator; 31. Outer bearing; 32. Follower frame;

[0054] 4. Rotary support mechanism; 41. Fixed joint; 42. Rotary drilling cap; 43. Intermediate cylinder; 44. Upper joint; 45. Bearing; 46. Locking nut;

[0055] 5. Injection section; 51. Injection channel; 52. Connection hole. Detailed Implementation

[0056] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0057] It is important to note that terms such as "first," "second," "symmetric," and "array" are used only to distinguish between descriptive and positional descriptions and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified with terms such as "first" or "symmetric" may explicitly or implicitly include one or more of that feature; similarly, when the quantity of certain features is not limited by words such as "two" or "three," it should be noted that such features also explicitly or implicitly include one or more features.

[0058] In this invention, unless otherwise explicitly specified and limited, terms such as "installation," "connection," and "fixation" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection, a direct connection, a welding connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the accompanying drawings and specific circumstances.

[0059] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0060] This utility model embodiment provides a telescopic down-the-hole hammer rotary drilling rod, which can be referred to as follows. Figures 1-2The drill rod comprises a working unit, a connecting part 2, a drive unit, and an air injection unit 5. The working unit has multiple coaxially nested working rod sections 1 that can move relative to each other axially, used to connect to the down-the-hole hammer. The working unit constitutes the main structure of the drill rod, enabling the transmission of torque and circumferential tensile / compressive force. Its nested structure minimizes the length of the drill rod when not in operation, facilitating transportation and positioning. During operation, it extends section by section to reach the predetermined drilling depth. The connecting part 2 is located at the top of the outermost working rod section 1, providing a rigid connection between the working unit and the drive unit, and is used by the drive unit to drive the working unit. The drive unit has a lifting actuator 3 connected to the connecting part 2, and a rotating support mechanism 4 connected to the lifting actuator 3. The drive unit connects to the drilling rig lifting mechanism and enables the rotation of the working unit relative to the rotating support mechanism 4, as well as driving the lifting and lowering of the working unit. The air injection unit 5 is located within the rotating support mechanism 4 and extends into the working unit, used to supply compressed air to the down-the-hole hammer.

[0061] As one implementation method of this embodiment, please refer to Figure 2 and Figures 6-7 ,

[0062] The working rod section 1 effectively transmits the rotational power from the drilling rig to the bottom-up down-the-hole hammer, driving it to rotate for rotary drilling. It enables deep drilling without disassembly and can retract after completion for easy relocation. The working rod section 1 includes a working rod 11, a keyed pressure block 12, a limiting block 13, and a rotary drilling square head 14. The working rod 11 has multiple sections; specifically, the number of working rods 11 can be set according to actual needs. In this embodiment, there are three working rods 11. The multiple sections of the working rod 11 have identical structures and gradually changing dimensions. The working rods 11 are coaxially nested sequentially, and any adjacent working rods 11 slide together to meet the drilling requirements at different depths. Simultaneously, the hollow cavity of each working rod 11 provides a channel for the delivery of compressed air.

[0063] Multiple keybar pressure blocks 12 are provided, arranged in groups of three. Each group of keybar pressure blocks 12 is evenly distributed circumferentially along the outer wall of the corresponding working rod 11. Specifically, the keybar pressure blocks 12 are arranged axially along the working rod 11, and their outer surfaces cooperate with the inner walls of adjacent working rods 11 to transmit torque from the outer working rods 11 to the inner working rods 11 step by step, thereby transmitting the rotational force of the drill rod. Simultaneously, the lower part of the outermost working rod 11 is connected to the drill rig power head via the keybar pressure blocks 12. Specifically, the drive keyway of the drill rig power head cooperates with the keybar pressure blocks 12 to transmit torque, thereby driving the rotation of the working rod 1. Multiple limiting blocks 13 are provided, arranged in groups of three. Each group of limiting blocks 13 is circumferentially distributed along the bottom of the inner wall of the corresponding working rod 11, with each limiting block 13 located between adjacent keybar pressure blocks 12. The key bar pressure block 12 is provided with a limiting groove 121 that cooperates with the limiting block 13. The limiting groove 121 cooperates with the limiting block 13 to limit the relative movement range of the working rod 11.

[0064] When the working length of the working rod 11 needs to be adjusted, as the inner working rod 11 extends downward relative to the outer working rod 11, the limiting block 13 fixed at the bottom of the inner working rod 11 moves downward together. When the limiting block 13 of the inner working rod 11 moves to correspond with the upper limit groove 121 of the key bar pressure block 12 of the outer working rod 11, by rotating the drill rod, the limiting block 13 of the inner working rod 11 engages with the upper limit groove 121 of the corresponding key bar pressure block 12 of the outer working rod 11, thereby locking the relative position between adjacent working rods 11 during drilling. In practice, multiple limiting grooves 121 can be set, and multiple limiting grooves 121 are spaced apart along the extension direction of the key bar pressure block 12 to meet the adjustment requirements of different lengths of the working rod 11.

[0065] The rotary drilling head 14 is fixedly connected to the bottom end of the innermost working rod 11; specifically, the rotary drilling head 14 has a rectangular cross-section and is used to connect with the matching sleeve on the top of the down-the-hole hammer. It can also be used to connect the drilling tools.

[0066] As one embodiment of this invention, refer to reference 5. The connecting part 2 includes a fixed flange 21, flange stiffeners 22, a rear flange 23, and a shock-absorbing pad 24. The fixed flange 21 is coaxially disposed at the top of the outermost working rod 11; the fixed flange 21 serves as a rigid connection interface between the working unit and the lifting actuator 3, providing an installation and connection surface for the lifting actuator 3. Multiple flange stiffeners 22 are provided, evenly distributed circumferentially along the outermost working rod 11, with one end of each flange stiffener 22 connected to the fixed flange 21. The flange stiffeners 22 enhance the connection strength and structural stability between the fixed flange 21 and the outermost working rod 11, ensuring a reliable connection between the working rod 1 and the lifting actuator 3. Simultaneously, they transfer the load borne by the fixed flange 21 to the pipe wall of the supporting working rod 11, avoiding stress concentration. The rear flange 23 is sleeved on the outermost working rod 11 and fixedly connected to the other end of each flange stiffener 22; the shock-absorbing pad 24 is sleeved on the outermost working rod 11 and connected to the rear flange 23. The rear flange 23 is located above the damping pad 24 and is fixedly connected to the other end of the flange stiffener 22, further enhancing the rigidity of the flange stiffener 22 itself and the connection strength with the working rod 11. At the same time, the damping pad 24 is used to absorb the vibration transmitted by the drilling rig power head. During use, vibration and impact are generated in the working area where the power head keyway and the key bar pressure block 12 meet, and diffuse into the tube wall of the working rod 11 through the connection between the key bar pressure block 12 and the working rod 11, and are transmitted upward along its tube wall to the outer wall surface of the working rod 11 in contact with the damping pad 24, causing periodic compression deformation of the damping pad 24. Internal friction is generated inside the elastic material of the damping pad 24, converting the mechanical energy of the vibration into heat energy and dissipating it, thereby attenuating the vibration energy that continues to be transmitted upward.

[0067] As one implementation method of this embodiment, please refer to Figure 5 The lifting actuator 3 includes an outer bearing 31 and a follower frame 32. The outer bearing 31 is coaxially mounted on a fixed flange 21, and its outer ring is fixedly connected to the fixed flange 21 by bolts. The outer bearing 31 is designed to withstand axial loads. When the lifting force of the drilling rig acts on the inner ring of the outer bearing 31, the outer bearing 31 transmits the force to the fixed flange 21, thereby driving the lifting of the working unit. The follower frame 32 is coaxially mounted on the outer bearing 31 and fixedly connected to the inner ring of the outer bearing 31. Its other end is slidably connected to the drilling rig mast.

[0068] When the working unit rotates under the drive of the power head, the follower frame 32, which is connected to the inner ring of the outer bearing 31, can remain stationary, providing stable guidance and support for the lifting and lowering of the drill rod.

[0069] As one implementation method of this embodiment, please refer to Figures 4-5The rotating support mechanism 4 includes a fixed joint 41, a rotary drilling cap 42, an intermediate cylinder 43, an upper joint 44, a bearing 45, a locking nut 46, and a connecting plate 47. The fixed joint 41 is coaxially arranged with the follower frame 32; the rotary drilling cap 42 is coaxially arranged inside the follower frame 32, with its upper end fixedly connected to the bottom end of the fixed joint 41 and its lower end engaging with the top end of the innermost working rod 11. Specifically, the rotary drilling cap 42 has a hollow cylindrical structure with an open bottom, which, when engaging with the top end of the innermost working rod 11, prevents external debris from entering the nested gaps of the multi-layered working rods 11 and guides the initial position of the innermost working rod 11. The intermediate cylinder 43 is coaxially arranged with the fixed joint 41, and its bottom is threadedly connected to the fixed joint 41, forming a static support shell. The upper connector 44 is mounted on the intermediate cylinder 43, with its bottom end extending into the rotary drilling cap 42. Multiple bearings 45 are provided, sequentially sleeved on the upper connector 44. The outer wall of each bearing 45 mates with the inner wall of the intermediate cylinder 43, serving to bear the radial load of the upper connector 44 and its connected components. Simultaneously, the upper connector 44 is allowed to rotate relative to the static outer shell formed by the intermediate cylinder 43 and the fixed connector 41 under axial load. Two locking nuts 46 are provided, located at the bottom of the upper connector 44 and threadedly connected to the upper connector 44. The upper locking nut 46 abuts against the inner ring of the corresponding bearing 45 to fix the axial position of the bearing 45. The connecting plate 47 is rotatably connected to the upper connector 44 and is used to connect to the drilling rig lifting mechanism. Among them, the outer ring of the uppermost bearing 45 abuts against the intermediate cylinder 43, and its inner ring abuts against the upper connector 44. The outer ring of the lowermost bearing 45 abuts against the fixed connector 41, and its inner ring abuts against the locking nut 46.

[0070] The rotating support mechanism 4 prevents the main coiled wire rope from being twisted, broken, or kinked during rotation.

[0071] As one implementation method of this embodiment, please refer to Figure 5 The air injection unit 5 includes an air injection channel 51 and a connecting hole 52. The air injection channel 51 is vertically shaped ("Z") and arranged along the axis of the upper connector 44, used to introduce compressed air; specifically, the air injection channel 51 connects to an external pipeline to form a compressed air inlet. The connecting hole 52 is located at the bottom of the outermost working rod 1 and communicates with the air injection channel 51, delivering compressed air to the down-the-hole hammer through a connection with an air pipe.

[0072] In specific implementation of this utility model:

[0073] 1. Non-working status:

[0074] The drill pipe is in a retracted state: the multi-section working rod part 1 (including the working rod 11) of the working unit is coaxially nested, with the innermost working rod 11 retracting into the innermost working rod 11, minimizing the total length of the drill pipe and facilitating transportation and on-site positioning. At this time, the limiting block 13 and the uppermost limiting groove 121 on the key bar pressure block 12 are in a mating state, achieving relative fixation of the working rod 11.

[0075] During positioning, the drilling rig lifting mechanism is connected to the drilling rig lifting mechanism through the connecting plate 47 of the drive unit, and the follower frame 32 slides with the drilling rig mast to ensure that the drill rod is vertically aligned with the drilling position.

[0076] 2. Work Start and Initial Driver:

[0077] Rotary drive: The drill rig power head (not shown) cooperates with the key bar pressure block 12 at the lower part of the outermost working rod 11 to transmit rotational torque. The torque is transmitted step by step to the inner working rod 11 through the key bar pressure block 12, and finally drives the down-the-hole hammer to rotate through the rotary drilling square head 14 at the bottom of the innermost working rod 11 to perform rotary drilling cutting.

[0078] Lifting Drive: The drilling rig lifting mechanism applies axial force through the connecting plate 47, which is transmitted to the lifting actuator 3 via the upper joint 44 of the rotating support mechanism 4. The inner ring of the outer bearing 31 is fixed to the follower frame 32, and the outer ring is connected to the fixed flange 21, thereby transmitting the axial force to the working unit and driving the drill rod to lift and lower. The follower frame 32 slides on the drilling rig mast, providing stable guidance and preventing swaying.

[0079] 3. Extension and retraction adjustment during drilling:

[0080] As the drilling depth increases, the inner working rod 11 needs to extend section by section:

[0081] Extension process: Under the influence of gravity, the inner working rod 11 slides downward relative to the outer working rod 11. The key bar pressure block 12 maintains a sliding fit with the inner wall of the working rod 11. Based on the operator's experience, when the inner working rod 11 moves to the predetermined position, the drill head drives the drill rod to rotate slowly, so that the limiting block 13 at the bottom of the inner working rod 11 aligns and engages with the limiting groove 121 on the key bar pressure block 12 of the outer working rod 11. The limiting groove 121 is spaced apart along the axial direction of the key bar pressure block 12, allowing adjustment of different extension lengths. After locking, the relative position between adjacent working rods 11 is fixed, preventing accidental retraction during drilling and ensuring stable drilling depth.

[0082] Retraction process: After drilling is completed, the drilling rig lifting mechanism applies an upward pulling force to remove the drill rod, then pushes the inner working rod 11 back into the outermost working rod 11, and finally rotates the inner working rod 11.

[0083] This ensures that the limiting block 13 on the adjacent inner working rod 11 is in a mating state with the uppermost limiting groove 121 of the key bar pressure block 12 on the adjacent outer working rod 11, thereby achieving relative fixation of the working rod 11.

[0084] 4. Torque and Axial Force Transmission

[0085] Torque transmission: Rotational power is transmitted from the drill rig power head through the key bar pressure block 12 of the outermost working rod 11, and then transmitted inward step by step through the key bar pressure block 12 of the nested working rod 11, and finally output to the down-the-hole hammer through the rotary drilling square head 14.

[0086] 5. Compressed air delivery:

[0087] Compressed air is introduced from an external air source through the air injection channel 51 of the air injection unit 5. The air is then transported downwards through the internal channels of the nested working rod 11, eventually reaching the down-the-hole hammer to drive its impact operation. The air injection channel 51 is integrated with the rotating support mechanism 4 to ensure continuous airflow when the drill rod rotates.

[0088] 6. Vibration reduction and stability control:

[0089] Vibration during drilling is absorbed by damping pad 24: vibration is transmitted from the drill head to the working rod 11 wall through key bar pressure block 12, and then upward to damping pad 24. The elastic material of damping pad 24 undergoes periodic compression, converting the mechanical energy of vibration into heat energy for dissipation, reducing the upward transmission of vibration, and protecting the drive unit and drill structure.

[0090] The bearings 45 of the rotating support mechanism 4 (multiple bearings are sleeved on the upper joint 44) bear radial loads, allowing the upper joint 44 to rotate relative to the intermediate cylinder 43 under axial loads, thus preventing the main coiled wire rope from winding or twisting. The locking nut 46 fixes the axial position of the bearings 45 to ensure rotational stability.

[0091] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A telescopic down-the-hole hammer rotary drill rod, characterized by include: The working unit has multiple coaxially nested working rods (1) that can move relative to each other axially, for connection with the down-the-hole hammer; The connecting part (2) is located at the top of the outermost working rod part (1); The drive unit has a lifting actuator (3) connected to the connecting part (2) and a rotating support mechanism (4) connected to the lifting actuator (3). The drive unit is used to connect the drilling rig lifting mechanism and realize the rotation of the working unit relative to the rotating support mechanism (4), as well as drive the lifting of the working unit. The air injection unit (5) is located inside the rotating support mechanism (4) and extends into the working unit for supplying compressed air to the downhole hammer.

2. A telescopic chaser hammer drill rod according to claim 1, characterized in that, The working rod (1) includes The working rod (11) has multiple sections. The multiple sections of the working rod (11) have the same structure and gradually change in size. Each of the working rods (11) is coaxially nested in sequence, and any adjacent working rods (11) are slidably fitted. Multiple key bar pressure blocks (12) are provided, in groups of three, and each group of key bar pressure blocks (12) is uniformly arranged along the outer circumference of the corresponding working rod (11); There are multiple limit blocks (13), three in a group, and each group of limit blocks (13) is arranged circumferentially along the bottom of the inner wall of the corresponding working rod (11); The rotary drilling head (14) is fixedly connected to the bottom end of the innermost working rod (11); The key bar pressure block (12) is provided with a limiting groove (121) that cooperates with the limiting block (13). The limiting groove (121) cooperates with the limiting block (13) to limit the relative movement range of the working rod (11).

3. A telescopic down-the-hole hammer rotary drilling rod according to claim 2, characterized in that, The connecting part (2) includes: A fixed flange (21) is coaxially disposed at the top of the outermost working rod (11); Multiple flange stiffeners (22) are provided, and the multiple flange stiffeners (22) are evenly arranged around the outermost working rod (11). One end of each flange stiffener (22) is connected to the fixed flange (21). The rear flange (23) is fitted onto the outermost working rod (11) and is fixedly connected to the other end of each flange stiffener (22); The shock-absorbing pad (24) is fitted onto the outermost working rod (11) and connected to the rear flange (23).

4. A telescopic down-the-hole hammer rotary drilling rod according to claim 3, characterized in that, The lifting actuator (3) includes: An outer bearing (31) is coaxially mounted on a fixed flange (21), and its outer ring is fixedly connected to the fixed flange (21) by bolts. The follower frame (32) is coaxially mounted on the outer bearing (31) and is fixedly connected to the inner ring of the outer bearing (31).

5. A telescopic down-the-hole hammer rotary drilling rod according to claim 4, characterized in that, The rotating support mechanism (4) includes: The fixed joint (41) is coaxially arranged with the follower frame (32); The rotary drilling cap (42) is coaxially arranged inside the follower frame (32). The upper end of the rotary drilling cap (42) is fixedly connected to the bottom end of the fixed joint (41), and the lower end is matched with the top end of the innermost working rod (11). The intermediate cylinder (43) is coaxially arranged with the fixed joint (41), and its bottom is threadedly connected to the fixed joint (41); The upper connector (44) is set on the intermediate cylinder (43), and its bottom end extends into the rotary drilling cap (42); There are multiple bearings (45), and the multiple bearings (45) are sequentially sleeved on the upper connector (44), and the outer wall of each bearing (45) is fitted with the inner wall of the intermediate cylinder (43); There are two locking nuts (46), which are located at the bottom of the upper connector (44) and are threaded to the upper connector (44). The locking nut (46) located on the upper side abuts against the inner ring of the corresponding bearing (45) to fix the axial position of the bearing (45). The connecting plate (47) is rotatably connected to the upper connector (44) and is used to connect to the drilling rig lifting mechanism; Among them, the outer ring of the uppermost bearing (45) abuts against the middle cylinder (43), and its inner ring abuts against the upper connector (44). The outer ring of the lowermost bearing (45) abuts against the fixed connector (41), and its inner ring abuts against the locking nut (46).

6. A telescopic down-the-hole hammer rotary drilling rod according to claim 1, characterized in that, The gas injection section (5) includes: The air injection channel (51) is vertically shaped like a "Z" and is set along the axis of the upper connector (44) for introducing compressed air; A connecting hole (52) is provided at the bottom of the outermost working rod (1) and is connected to the air injection channel (51) to deliver compressed air to the downhole hammer.

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