A high-pressure sealing drill rod

Abstract

This invention relates to a high-pressure sealing drill pipe, comprising at least a drill pipe body with an internal fluid flow channel. One end of the drill pipe body has a male connector, and the other end has a female connector. The male connector includes a first tapered segment extending outward from the end face of the drill pipe body along the axis, forming a gradually tapering cross-section, and a second tapered segment extending outward from the end face of the first tapered segment along the axis, forming a gradually tapering cross-section. The outer circumferential surface of the first tapered segment is provided with an external tapered thread. The female connector includes an internal tapered thread segment adapted to the first tapered segment and an internal tapered hole segment adapted to the second tapered segment. The wall surface of the internal tapered hole segment is provided with an annular groove and an O-ring seal adapted to the annular groove. This invention achieves a high-pressure sealing effect at the drill pipe connection with only a small torque. During drill pipe rotation, the seal effectively avoids wear caused by rotational friction, resulting in a longer service life, significantly reducing the risk of leakage, and providing good centering during drill pipe connection operations.

Description

Technical Field

[0001] This utility model relates to the field of drilling construction machinery technology, specifically to a high-pressure sealed drill rod. Background Technology

[0002] In drilling operations, such as tunnel engineering, dam reinforcement, or underground mining, deep and long borehole construction (e.g., pre-drilled holes, blasting holes, casing drilling, etc.) is required, with depths ranging from tens to hundreds of meters. High-pressure water-driven down-the-hole (DHH) percussion drilling technology is employed, using high-pressure water as the driving medium for the piston impact of the high-pressure water-powered actuator. High-pressure water (maximum working pressure approximately 180 bar) is delivered to the DHH percussion actuator through the drill pipe. Therefore, the drill pipe must be able to transmit drilling torque of 2000~4000 Nm while also withstanding high-pressure water pressure of 200 bar or even higher, ensuring that the high-pressure water does not leak as it passes through the drill pipe.

[0003] While oilfield drill pipes and their connection methods can meet high-pressure water requirements, the pressure-resistant seals used in the pipe connections employ hard seals, requiring extremely high torque (over 10,000 Nm) for tightening. This significantly increases the torque requirements of the drill rig's power head and also greatly increases the difficulty of pipe removal. In contrast, the working torque required during down-the-hole percussion drilling is only about 2,000 Nm, eliminating the need for a high-power rotary power head and pipe removal device.

[0004] During operation, the flushing water or compressed air pressure delivered inside the drill rod of ordinary rotary cutting drills and pneumatic down-the-hole impact drills is only 10-30 bar. This is unsuitable for the high-pressure water sealing requirements of high-pressure hydrodynamic down-the-hole impact drilling. In actual operation, leaks are easily caused at the drill rod connection points, resulting in insufficient water pressure, which seriously affects the impact drilling efficiency of the high-pressure hydrodynamic down-the-hole impactor and also causes unnecessary energy loss. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a high-pressure sealing effect at the drill pipe connection that can be achieved by applying only a small torque. During the rotation of the drill pipe connection, the sealing ring equipped thereon can effectively avoid wear caused by rotational friction, thus having a longer service life and significantly reducing the risk of leakage. At the same time, it provides a high-pressure sealing drill pipe with good neutrality during the drill pipe connection operation.

[0006] To solve the above-mentioned technical problems, the present invention provides a high-pressure sealed drill rod, which includes at least a drill rod body with an internal fluid flow channel, wherein a male connector is provided at one end of the drill rod body and a female connector is provided at the other end.

[0007] The male connector includes a first tapered segment extending outward from the end face of the drill pipe body along the axis to form a gradually tapering cross section, and a second tapered segment extending outward from the end face of the first tapered segment along the axis to form a gradually tapering cross section. The outer peripheral surface of the first tapered segment is provided with an external tapered thread.

[0008] The female connector includes an internal tapered thread section adapted to the first tapered section and an internal tapered hole section adapted to the second tapered section. The wall surface of the internal tapered hole section is provided with an annular groove and an O-ring seal adapted to the annular groove.

[0009] In a preferred embodiment, the bottom wall of the annular groove is provided with a conical surface, which gradually tapers along the direction from the female connector to the male connector.

[0010] In a preferred embodiment, the end of the second cone segment away from the first cone segment is provided with a rounded corner.

[0011] In a preferred embodiment, the male connector is provided with a flow hole that communicates with the flow channel, and the flow hole is coaxial with the flow channel.

[0012] In a preferred embodiment, a guide hole is provided between the liquid flow hole and the liquid flow channel, and the guide hole gradually widens along the direction of the liquid flow channel.

[0013] In a preferred embodiment, a second liquid flow hole is provided at the end of the inner tapered hole section away from the inner tapered thread section, which is connected to the liquid flow channel, and the second liquid flow hole is coaxially arranged with the liquid flow channel.

[0014] In a preferred embodiment, a guide hole two is provided at a position between the liquid flow hole two and the liquid flow channel, which gradually widens along the direction of the liquid flow hole two towards the liquid flow channel.

[0015] In a preferred embodiment, the inner diameters of the first liquid flow hole and the second liquid flow hole are the same.

[0016] In a preferred embodiment, the inner diameters of both the first and second liquid flow holes are smaller than the inner diameter of the liquid flow channel.

[0017] In a preferred embodiment, the end of the internal tapered thread section away from the internal tapered hole section is provided with a chamfer.

[0018] Compared with the prior art, the high-pressure sealing drill rod of this utility model has the following advantages:

[0019] The high-pressure sealed drill rod of this utility model includes at least a drill rod body with an internal fluid flow channel. The internal fluid flow channel is the key path for high-pressure water transportation, which can ensure that high-pressure water is smoothly transported through the drill rod to the down-the-hole impactor, thus meeting the requirement of high-pressure water as the driving medium in the down-the-hole impact drilling technology in deep and long drilling construction and ensuring the normal progress of drilling operations.

[0020] The drill pipe body has a male connector at one end and a female connector at the other end. The male connector includes a first tapered section extending outward from the end face of the drill pipe body along the axis, forming a cross-section with a tapered shape, and a second tapered section extending outward from the end face of the first tapered section along the axis, forming a cross-section with a gradually narrowing shape. The outer circumferential surface of the first tapered section is provided with an external tapered thread. The female connector includes an internal tapered thread section that matches the first tapered section and an internal tapered hole section that matches the second tapered section. On the one hand, the tapered shape of the first tapered section provides good guidance during drill pipe connection. When the male and female connectors are mated, the first tapered section guides them to be accurately aligned. Compared with ordinary drill pipes that rely solely on threaded connection for alignment, this greatly improves coaxial accuracy and makes the alignment of the drill pipe connection better. On the other hand, good alignment ensures more uniform stress on the threads when transmitting drilling torque, avoiding thread wear or damage caused by excessive local stress, which helps extend the service life of the drill pipe and reduce drill pipe replacement costs during construction. The external tapered thread mates with the internal tapered thread section of the female connector, not only achieving the connection between drill pipes but also providing the basic structure for sealing. The tight engagement of the threads prevents high-pressure water leakage to a certain extent, and combined with the subsequent sealing ring structure, further enhances the sealing effect.

[0021] The inner tapered section of the female connector has an annular groove and an O-ring that matches the groove. Firstly, the O-ring is located within the annular groove, providing a precise installation position and ensuring it is correctly positioned during drill pipe connection for effective sealing. Secondly, during drill pipe rotation, the second tapered section separates from the O-ring until the first tapered section is fully tightened. This allows the second tapered section to press against the O-ring within the annular groove, resulting in a tighter fit between the male and female connectors. This effectively prevents wear caused by rotational friction, extending service life and significantly reducing the risk of leakage. The second tapered section further extends the male connector's structure to match the inner tapered section of the female connector. It plays a supporting role in positioning and sealing during drill pipe connection, working in conjunction with the first tapered section and the external tapered thread to ensure a tight and stable connection between the male and female connectors, enhancing the structural strength and sealing performance of the entire drill pipe connection. The second conical section forms a sealing structure with the O-ring seal within the annular groove, achieving a high-pressure seal at the drill pipe connection with only a small torque. Simultaneously, the combination of the annular groove and the sealing ring effectively prevents foreign objects from entering the drill pipe's internal channels. During drilling, various impurities and particles may exist on the outside of the drill pipe. If these foreign objects enter the drill pipe's internal channels, they may enter the high-pressure sealing components, causing jamming and wear, affecting the normal operation of the high-pressure hydraulic down-the-hole impactor. The sealing structure of this invention effectively avoids this situation, extending the equipment's service life and reducing construction delays and maintenance costs caused by equipment failure. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the drill rod structure of an embodiment of the high-pressure sealing drill rod of this utility model;

[0023] Figure 2 for Figure 1 Enlarged view of part A in the middle;

[0024] Figure 3 This is a schematic diagram of the high-pressure sealed drill rod connector of this utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-Drill pipe body; 11-Fluid flow channel; 2-Male connector; 21-First tapered section; 211-External tapered thread; 22-Second tapered section; 221-Round corner; 23-Fluid flow hole one; 24-Guide hole one; 3-Female connector; 31-Internal tapered thread section; 311-Chamfer; 32-Internal tapered hole section; 321-Annular groove; 3211-Cone surface; 322-O-ring seal; 33-Fluid flow hole two; 34-Guide hole two. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0028] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to the internal connection of two components; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0030] This embodiment provides a high-pressure sealing drill rod, such as... Figure 1 and Figure 2 As shown, the drill pipe body 1 includes an internal fluid flow channel 11. One end of the drill pipe body has a male connector 2, and the other end has a female connector 3. The internal fluid flow channel is the key path for high-pressure water delivery, ensuring that high-pressure water is smoothly delivered through the drill pipe to the down-the-hole impactor. This meets the requirement of high-pressure water as the driving medium in deep and long borehole drilling technology, ensuring the normal operation of the drilling process.

[0031] The male connector 2 includes a first tapered section 21 formed by extending the end face of the drill pipe body 1 outward along the axis to form a gradually tapered cross section, and a second tapered section 22 formed by extending the end face of the first tapered section outward along the axis to form a gradually tapered cross section. The outer peripheral surface of the first tapered section is provided with an external tapered thread 211.

[0032] The female connector includes an internal tapered thread section 31 that matches the first tapered section and an internal tapered hole section 32 that matches the second tapered section. Firstly, the first tapered section is tapered, providing excellent guidance during drill pipe connection. When the male and female connectors mate, the first tapered section guides them to accurate alignment, significantly improving coaxial accuracy compared to ordinary drill pipes that rely solely on threaded connections for alignment, resulting in better alignment of the drill pipe connection. Secondly, this good alignment ensures more even stress distribution on the threads when transmitting drilling torque, preventing thread wear or damage caused by excessive localized stress, thus extending the service life of the drill pipe and reducing drill pipe replacement costs during construction. The external tapered thread mates with the internal tapered thread section of the female connector, not only achieving connection between drill pipes but also providing a basic structure for sealing. The tight engagement of the threads prevents high-pressure water leakage to a certain extent, and combined with the subsequent sealing ring structure, further enhances the sealing effect.

[0033] like Figure 2 and Figure 3 As shown, an annular groove 321 and an O-ring 322 adapted to the annular groove are provided on the wall surface of the inner conical bore section 32. On one hand, the O-ring is located within the annular groove on the wall surface of the inner conical bore section, providing a precise installation position for the O-ring and ensuring it is in the correct position during drill pipe connection, thus providing a good sealing effect. On the other hand, during the rotation of the drill pipe connection, the second conical section is separated from the O-ring until the first conical section is screwed into place. Only then does the second conical section press against the O-ring in the annular groove, making the O-ring fit more tightly against the contact surfaces of the male and female connectors. This effectively avoids wear caused by rotational friction, resulting in a longer service life and significantly reducing the risk of leakage. The second conical section further extends the structure of the male connector, adapting to the inner conical bore section of the female connector. It plays an auxiliary positioning and sealing role in the drill pipe connection, working together with the first conical section and the external conical thread to ensure a tight and stable connection between the male and female connectors, enhancing the structural strength and sealing performance of the entire drill pipe connection. The second conical section forms a sealing structure with the O-ring seal within the annular groove, achieving a high-pressure seal at the drill pipe connection with only a small torque. Simultaneously, the combination of the annular groove and the sealing ring effectively prevents foreign objects from entering the drill pipe's internal channels. During drilling, various impurities and particles may exist on the outside of the drill pipe. If these foreign objects enter the drill pipe's internal channels, they may enter the high-pressure sealing components, causing jamming and wear, affecting the normal operation of the high-pressure hydraulic down-the-hole impactor. The sealing structure of this invention effectively avoids this situation, extending the equipment's service life and reducing construction delays and maintenance costs caused by equipment failure.

[0034] like Figure 2As shown, the bottom wall of the annular groove 321 is provided with a conical surface 3211. The conical surface gradually tapers from the female joint to the male joint. The tapered conical surface causes the O-ring to undergo directional deformation under high pressure, avoiding stress relaxation. The sharp corners of the conical surface 3211 are rounded to avoid stress concentration.

[0035] In some of the illustrated embodiments, the bottom wall of the annular groove 321 is a cylindrical surface adapted to fit the O-ring seal.

[0036] In this embodiment, the end of the second cone segment 22 away from the first cone segment 21 is provided with a rounded corner 221 to avoid damage to the sealing ring during the connection of the drill pipe.

[0037] like Figure 1 As shown, the male connector 2 is provided with a liquid flow hole 23 that is connected to the liquid flow channel 11. The liquid flow hole 23 is coaxial with the liquid flow channel to ensure that the high-pressure water flow is transmitted without deflection, avoid the fluid from generating eddies due to channel misalignment, and reduce pressure loss.

[0038] Preferably, a guide hole 24 is provided between the liquid flow hole 23 and the liquid flow channel 11, which gradually widens along the direction of the liquid flow hole to the liquid flow channel, so that the high pressure diffuses horizontally and reduces turbulence and local pressure peaks.

[0039] The inner tapered hole section 32 is provided with a second liquid flow hole 33 connected to the liquid flow channel 11 at the end away from the inner tapered thread section 31. The second liquid flow hole is coaxial with the liquid flow channel to ensure that the high pressure water flow is transmitted without deflection, avoid the fluid from generating eddies due to channel misalignment, and reduce pressure loss.

[0040] Preferably, a guide hole 34 is provided between the liquid flow hole 33 and the liquid flow channel 11, which is gradually widened along the direction of the liquid flow channel to allow the high pressure to diffuse horizontally and reduce turbulence and local pressure peaks.

[0041] In this embodiment, the inner diameters of liquid flow hole 1 23 and liquid flow hole 2 33 are the same, forming a seamless flow channel transition, thus avoiding fluid stripping and local cavitation risk caused by abrupt changes in orifice diameter.

[0042] Preferably, the inner diameters of both the first liquid flow hole 23 and the second liquid flow hole 33 are smaller than the inner diameter of the liquid flow channel, which increases the local flow velocity and reduces the local pressure. On the one hand, this enhances the self-cleaning effect of the fluid on the pipe wall; on the other hand, it reduces the impact on the sealing structure formed by the O-ring seal in the second cone section and the annular groove, thereby improving the sealing performance.

[0043] In this embodiment, the end of the internal tapered thread section 31 away from the internal tapered hole section 32 is provided with a chamfer 311.

[0044] In summary, the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-pressure sealing drill rod, characterized in that: It includes at least a drill pipe body (1) with a fluid flow channel (11) inside, and a male connector (2) is provided at one end of the drill pipe body and a female connector (3) is provided at the other end. The male connector (2) includes a first tapered section (21) formed by extending outward along the axis from the end face of the drill rod body (1) to form a gradually narrowing cross section, and a second tapered section (22) formed by extending outward along the axis from the end face of the first tapered section to form a gradually narrowing cross section. The outer peripheral surface of the first tapered section (21) is provided with an external tapered thread (211). The female connector (3) includes an internal tapered thread section (31) adapted to the first tapered section and an internal tapered hole section (32) adapted to the second tapered section. An annular groove (321) and an O-ring (322) adapted to the annular groove are provided on the wall surface of the internal tapered hole section.

2. A high-pressure sealing drill rod according to claim 1, characterized in that: The bottom wall of the annular groove (321) is provided with a conical surface (3211), which gradually narrows along the direction of the female connector toward the male connector.

3. A high-pressure sealing drill rod according to claim 1 or 2, characterized in that: The second cone segment (22) has a rounded corner (221) at the end away from the first cone segment.

4. A high-pressure sealing drill rod according to claim 1 or 2, characterized in that: The male connector (2) is provided with a liquid flow hole (23) that communicates with the liquid flow channel (11), and the liquid flow hole is coaxial with the liquid flow channel.

5. A high-pressure sealing drill rod according to claim 4, characterized in that: A guide hole (24) is provided between the liquid flow hole (23) and the liquid flow channel (11), which gradually widens along the direction of the liquid flow hole (23) towards the liquid flow channel.

6. A high-pressure sealing drill rod according to claim 5, characterized in that: The inner conical hole section (32) is provided with a liquid flow hole two (33) connected to the liquid flow channel (11) at the end away from the inner conical thread section (31). The liquid flow hole two is coaxial with the liquid flow channel.

7. A high-pressure sealing drill rod according to claim 6, characterized in that: A guide hole (34) is provided between the liquid flow hole (33) and the liquid flow channel (11), which gradually widens along the direction of the liquid flow hole (33) towards the liquid flow channel.

8. A high-pressure sealing drill rod according to claim 7, characterized in that: The inner diameter of the first liquid flow hole (23) is the same as that of the second liquid flow hole (33).

9. A high-pressure sealing drill rod according to claim 8, characterized in that: The inner diameters of both the first liquid flow hole (23) and the second liquid flow hole (33) are smaller than the inner diameter of the liquid flow channel.

10. A high-pressure sealing drill rod according to any one of claims 1-2, 5, or 7-9, characterized in that: The inner tapered thread section (31) is provided with a chamfer (311) at the end away from the inner tapered hole section (32).

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