Variable-diameter pressure relief drill rod structure

Abstract

The invention relates to the technical field of drill rods, and discloses a variable-diameter pressure relief drill rod structure which comprises a tail-section inner rod, an adjusting disc assembly is rotatably connected to the interior of the rear end of the tail-section inner rod through a cross-shaped support, and the inner side end of a reaming part is slidably connected with the adjusting disc assembly; a motor fixed in the middle of the rear end of the cross-shaped support is used for driving an adjusting disc assembly to rotate, and the rotation of the adjusting disc assembly achieves telescopic diameter changing of the reaming piece relative to the tail-section inner rod; a follow-up gear piece meshed with a center gear at the front end of the adjusting disc assembly is further arranged on the cross-shaped support, a locking assembly is installed at the front end of the cross-shaped support through an extension plate, and the locking assembly fixes the adjusting disc assembly and the reaming piece by clamping the follow-up gear piece. The device is flexible and accurate in diameter change and high in adaptability, can perform different drilling diameter operations in different sections of various roadways, improves more flexibility and efficiency for a drilling pressure relief technology, is reliable and stable in locking, and guarantees operation safety.

Description

Technical Field

[0001] This invention relates to the field of drill pipe technology, specifically a variable diameter pressure relief drill pipe structure. Background Technology

[0002] Rockburst is a dynamic phenomenon that causes severe damage to coal and rock in mine roadways or working faces. To improve the safety of roadway excavation operations, large-diameter drill rods are typically used for drilling to relieve pressure, releasing or transferring high stress to deeper areas and eliminating stress concentration in the excavation zone.

[0003] However, existing pressure relief drill pipe structures generally have the following defects: First, the hole diameter is fixed and cannot be adjusted, which cannot adapt to the pressure relief drilling needs of different geological conditions and different stress distribution areas, resulting in extremely poor flexibility; Second, the hole enlargement structure is loosely connected to the drill pipe body, lacks a precise drive positioning mechanism, has low hole enlargement diameter adjustment accuracy, and is prone to diameter deviation due to vibration during drilling, leading to unstable pressure relief effect. Therefore, we have introduced a variable diameter pressure relief drill pipe structure. Summary of the Invention

[0004] The purpose of this invention is to provide a variable diameter pressure relief drill pipe structure to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A variable diameter pressure relief drill rod structure includes a final inner rod, a drill bit connected to the front end of the final inner rod, and reamers connected in a circular, equally spaced telescopic manner on the final inner rod. An adjustment disc assembly is rotatably connected to the rear end of the final inner rod via a cross bracket, and the inner end of the reamer is slidably connected to the adjustment disc assembly. The motor fixed at the middle of the rear end of the cross bracket is used to drive the rotation of the adjustment plate assembly. The rotation of the adjustment plate assembly realizes the expansion and contraction of the hole expander relative to the inner rod of the last section. The cross bracket is also provided with a follower gear that meshes with the central gear at the front end of the adjustment disc assembly. The front end of the cross bracket is equipped with a locking assembly by an extension plate. The locking assembly fixes the adjustment disc assembly and the enlarged hole component by clamping the follower gear.

[0006] Preferably, the drill bit has an external threaded post at the center of its rear end, and the external threaded post is screwed into the internal threaded connection hole at the front end of the last section of the inner rod.

[0007] Preferably, the surface of the inner rod of the last section has circularly spaced through grooves, which are connected to the central cavity at the rear end of the inner rod of the last section. The hole-expanding component includes a slider inserted through a through slot, an arc-shaped hole-expanding plate connected to the outer end of the slider, and an inwardly tapered arc-shaped inclined plate connected to the side of the arc-shaped hole-expanding plate. The surfaces of the arc-shaped hole-expanding plate and the inwardly tapered arc-shaped inclined plate are provided with hole-expanding protrusions.

[0008] Preferably, the inner end of the slider is provided with a first sliding rod; The cross-shaped bracket is supported on the inner wall of the central cavity. The adjustment disk assembly includes an I-shaped turntable. The side wall of the I-shaped turntable is provided with a first sliding groove. The two ends of the first sliding rod are slidably connected to the corresponding first sliding groove.

[0009] Preferably, the central gear is fixed at the front end of the I-shaped turntable, and the rotating shaft fixed in the middle of the central gear passes through the cross bracket and is connected to the motor output end.

[0010] Preferably, the follower gear includes a rotating rod movably connected to the cross bracket, a front gear fixed at the front end of the rotating rod, and a driven gear fixed at the rear end of the rotating rod, wherein the front gear meshes with the central gear.

[0011] Preferably, the locking assembly includes an electric cylinder, a cross-shaped moving seat fixed at the output end of the electric cylinder, a drive arm slidably connected to the cross-shaped moving seat, and an arc-shaped latching tooth seat fixed at the front end of the drive arm. The drive arm is movably connected between the two corresponding extension plates using a pin shaft.

[0012] Preferably, a cross-shaped fixing seat is fixed at the rear end of the extension plate, the electric cylinder is fixed in the center at the rear end of the cross-shaped fixing seat, and the piston rod at the output end of the electric cylinder passes through the cross-shaped fixing seat and is connected and fixed to the cross-shaped moving seat. The U-shaped seat on the cross-shaped moving seat slides between the two corresponding sets of extension plates, and the rear end of the drive arm is fixed with a second sliding rod. The side wall of the U-shaped seat is provided with a second sliding groove, and the two ends of the second sliding rod slide into the corresponding second sliding groove.

[0013] Compared with the prior art, the beneficial effects of the present invention are: the present invention has flexible and precise diameter change and strong adaptability: the rotational motion is converted into the extension and retraction motion of the hole expander, which can precisely adjust the extension length of the arc-shaped hole expander plate and realize flexible switching of the drilling diameter. Different drilling diameter operations can be carried out in different sections of various roadways, which improves the flexibility and efficiency of drilling pressure relief technology. This invention provides a reliable and stable locking mechanism, ensuring operational safety: After the reaming component is adjusted to the target diameter, the locking assembly, driven by an electric cylinder and transmitted through a cross-shaped moving seat and drive arm, precisely engages the driven gear of the follower gear component with the arc-shaped snap-fit ​​tooth seat, indirectly fixing the adjusting disc assembly and the reaming component. This locking method provides a strong connection and high locking force, effectively resisting vibration interference during drilling, preventing reaming diameter deviation, and ensuring the dimensional accuracy and stability of the pressure-relief borehole. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the exploded structure of the assembly of the present invention; Figure 2 This is an exploded structural diagram of the drill bit and the end section inner rod assembly of the present invention; Figure 3 A schematic diagram showing the structure of the cross bracket, motor, extension plate, and end section inner rod of the present invention; Figure 4 This is a three-dimensional structural diagram of the hole-expanding component of the present invention; Figure 5 This is an exploded structural diagram showing the connection between the adjusting disc assembly and the follower gear of the present invention; Figure 6 This is a three-dimensional structural diagram showing the connection between the hole-expanding component, the adjusting disk assembly, and the follower gear component of the present invention; Figure 7 This is a cross-sectional schematic diagram showing the connection between the hole-expanding component, the end section inner rod, the adjusting disc assembly, and the follower gear component of the present invention. Figure 8 This is an exploded structural diagram of the locking assembly of the present invention; Figure 9 This is a schematic diagram of the structure of the locking component and the follower gear when they are engaged. Figure 10 This is a three-dimensional structural diagram of the entire invention; Figure 11 For the present invention Figure 10 A schematic diagram of the three-dimensional structure from another perspective; Figure 12 For the present invention Figure 10 A cross-sectional structural diagram.

[0015] In the diagram: 1. Drill bit; 101. External threaded post; 2. Reamer; 201. Slider; 202. First sliding rod; 203. Arc-shaped reaming plate; 204. Inwardly tapered arc-shaped inclined plate; 205. Reaming protrusion; 3. End section inner rod; 301. Internal threaded connecting hole; 302. Through groove; 303. Connecting flange; 304. Cross bracket; 305. Motor; 306. Extension plate; 4. Adjusting disc assembly; 401. I-shaped turntable; 402. First... 403. Sliding groove; 404. Center gear; 405. Rotating shaft; 5. Follower gear; 506. Front gear; 507. Driven gear; 508. Rotating rod; 6. Locking assembly; 609. Electric cylinder; 600. Cross fixed seat; 601. Piston rod; 602. Cross movable seat; 603. U-shaped seat; 604. Second sliding groove; 605. Drive arm; 606. Pin; 607. Second sliding rod; 610. Arc-shaped snap-fit ​​tooth seat. Detailed Implementation

[0016] 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.

[0017] Example: Please see Figures 1-12 The present invention provides a technical solution: A variable diameter pressure relief drill pipe structure includes a final inner rod 3. A connecting flange 303 is provided on the outer rear end of the final inner rod 3. The final inner rod 3 serves as the main load-bearing structure of the entire drill pipe. The connecting flange 303 on the outer rear end is used to connect with other sections of the drill pipe to achieve splicing of the entire drill pipe and ensure smooth power transmission during drilling. A drill bit 1 is connected to the front end of the final inner rod 3. An external threaded post 101 is provided in the center of the rear end of the drill bit 1. The external threaded post 101 is screwed into the internal threaded connecting hole 301 at the front end of the final inner rod 3.

[0018] The external threaded post 101 at the rear end of the drill bit 1 is screwed into the internal threaded connection hole 301 at the front end of the end section inner rod 3, so as to realize the firm connection between the drill bit 1 and the end section inner rod 3, ensuring that the drill bit 1 can stably withstand the drilling impact force during drilling, avoiding loosening or falling off, and at the same time facilitating the disassembly and replacement of the drill bit 1, making it easy to replace different models of drill bit 1 to adapt to different drilling needs.

[0019] The inner rod 3 of the last section has a circular, equally spaced, telescopically connected expansion member 2. The inner rod 3 of the last section has circular, equally spaced through grooves 302 on its surface. The through grooves 302 are connected to the central cavity at the rear end of the inner rod 3 of the last section. The expansion member 2 includes a slider 201 inserted through the through groove 302, an arc-shaped expansion plate 203 connected to the outer end of the slider 201, and an inwardly tapered arc-shaped inclined plate 204 connected to the side of the arc-shaped expansion plate 203. The surfaces of the arc-shaped expansion plate 203 and the inwardly tapered arc-shaped inclined plate 204 are provided with expansion protrusions 205. The through grooves 302 are circularly equally spaced to provide telescopic guidance for the slider 201 of the expansion member 2, ensuring that the slider 201 moves smoothly and avoiding jamming.

[0020] The slider 201 of the reamer 2 is inserted through the through slot 302, serving to connect the adjusting disk assembly 4 and the arc-shaped reamer 203, transmitting the driving force of the adjusting disk assembly 4, and causing the arc-shaped reamer 203 to extend and retract. The first sliding rod 202 of the reamer 2 slides into the first sliding groove 402 of the adjusting disk assembly 4, realizing the conversion of rotational motion into extension and retraction motion, ensuring smooth extension and retraction and accurate diameter change of the reamer 2. The arc-shaped reamer 203 of the reamer 2 has an arc-shaped structure, which is consistent with the drilling... The inner wall of the hole has a high degree of fit, and the diameter of the hole can be precisely adjusted during expansion and contraction to adapt to different hole diameter requirements. The inwardly tapered arc-shaped inclined plate 204 of the hole expander 2 assists the arc-shaped hole expander plate 203 in expanding the hole, while guiding the rock cuttings out, reducing rock cuttings accumulation, and assisting in pressure relief. The hole expander protrusion 205 of the hole expander 2 is set on the surface of the arc-shaped hole expander plate 203 and the inwardly tapered arc-shaped inclined plate 204 to enhance the cutting ability during hole expansion, improve hole expansion efficiency, and at the same time disperse the hole wall pressure, assist in pressure relief, and prevent hole wall collapse.

[0021] The inner rear end of the last section of the inner rod 3 is rotatably connected to the adjustment disk assembly 4 via a cross bracket 304. The inner end of the enlarged hole 2 is slidably connected to the adjustment disk assembly 4. The cross bracket 304 is supported on the inner wall of the central cavity, providing a stable mounting support point for the adjustment disk assembly 4, the motor 305, the follower gear 5, and the locking assembly 6, ensuring that all components work together and preventing deviation or shaking during rotation. The inner end of the slider 201 is provided with a first sliding rod 202. The cross bracket 304 is supported on the inner wall of the central cavity. The adjustment disk assembly 4 includes an I-shaped turntable 401. The side wall of the I-shaped turntable 401 is provided with a first sliding groove 402. The two ends of the first sliding rod 202 are slidably connected to the corresponding first sliding groove 402.

[0022] The central gear 403 is centrally fixed at the front end of the I-shaped turntable 401. The rotating shaft 404 fixed in the middle of the central gear 403 passes through the cross bracket 304 and is connected to the output end of the motor 305. The motor 305 fixed in the middle of the rear end of the cross bracket 304 is used to drive the rotation of the adjusting disk assembly 4. The rotation of the adjusting disk assembly 4 realizes the expansion and contraction of the hole-expanding part 2 relative to the inner rod 3 of the last section. The I-shaped turntable 401 of the adjusting disk assembly 4 is the core of the adjusting disk assembly 4. When rotating, it drives the expansion and contraction of the hole-expanding part 2 through the first sliding groove 402. The structure is reasonably designed and the driving force is smoothly transmitted. It can drive multiple sets of hole-expanding parts 2 to expand and contract synchronously at the same time, ensuring that the hole diameter is uniform. The first sliding groove 402 of the adjusting disk assembly 4 and the first sliding groove of the hole-expanding part 2 are connected. The lever 202, in conjunction with the other two components, precisely converts the rotational motion of the I-shaped turntable 401 into the telescopic motion of the expanding part 2. The angle design of the first sliding groove 402 is adapted to the diameter change requirements, ensuring accurate, smooth, and uninterrupted diameter change. The central gear 403 of the adjusting disk assembly 4 is fixed to the rotating shaft 404 of the motor 305 and meshes with the follower gear 5. On the one hand, it transmits the power of the motor 305 to drive the I-shaped turntable 401 to rotate; on the other hand, it improves the rotational stability by meshing with the follower gear 5. The rotating shaft 404 of the adjusting disk assembly 4 connects the output end of the motor 305 and the central gear 403 to achieve precise power transmission and ensure that the driving force of the motor 305 can efficiently drive the central gear 403 and the I-shaped turntable 401 to rotate.

[0023] The cross bracket 304 is also provided with a follower gear 5 that meshes with the central gear 403 at the front end of the adjustment disc assembly 4. The follower gear 5 includes a rotating rod 503 movably connected to the cross bracket 304, a front gear 501 fixed at the front end of the rotating rod 503, and a driven gear 502 fixed at the rear end of the rotating rod 503. The front gear 501 meshes with the central gear 403.

[0024] The front gear 501 meshes with the central gear 403 and rotates synchronously with the central gear 403, which helps to stabilize the rotation trajectory of the central gear 403, prevents the central gear 403 from deviating or shaking when rotating, and ensures the stability of the rotation of the adjustment disk assembly 4.

[0025] Driven gear 502 is connected to front gear 501 via rotating rod 503 and rotates synchronously. It serves as the clamping target point of locking assembly 6. By clamping driven gear 502, the center gear 403 and adjusting disc assembly 4 can be indirectly fixed, thereby achieving the locking of the enlarged hole part 2.

[0026] The front end of the cross bracket 304 is equipped with a locking component 6 via an extension plate 306. The locking component 6 includes an electric cylinder 601, a cross moving seat 604 fixed at the output end of the electric cylinder 601, a drive arm 607 slidably connected to the cross moving seat 604, and an arc-shaped snap-fit ​​tooth seat 610 fixed at the front end of the drive arm 607. The drive arm 607 is movably connected between the two corresponding extension plates 306 via a pin 608.

[0027] A cross-shaped fixing seat 602 is fixed to the rear end of the extension plate 306. The electric cylinder 601 is fixed to the rear end of the cross-shaped fixing seat 602 in the center. The piston rod 603 at the output end of the electric cylinder 601 passes through the cross-shaped fixing seat 602 and is connected and fixed to the cross-shaped moving seat 604. The U-shaped seat 605 on the cross-shaped moving seat 604 slides between the corresponding two sets of extension plates 306. A second sliding rod 609 is fixed to the rear end of the drive arm 607. A second sliding groove 606 is provided on the side wall of the U-shaped seat 605. The two ends of the second sliding rod 609 slide in the corresponding second sliding groove 606.

[0028] The extension plate 306 provides an installation carrier for the locking assembly 6, ensuring the accurate installation position of the locking assembly 6, and at the same time provides support for the rotation of the drive arm 607, ensuring the smooth realization of the locking action. The locking assembly 6 fixes the adjusting plate assembly 4 and the expanding hole part 2 by clamping the follower gear part 5.

[0029] The electric cylinder 601 serves as the drive source for the locking assembly 6, providing stable power output and precisely controlling the movement distance of the cross-shaped moving seat 604. This, in turn, controls the clamping force of the arc-shaped latching tooth seat 610, adapting to different locking requirements. The cross-shaped fixing seat 602 provides stable mounting support for the electric cylinder 601, ensuring that the electric cylinder 601 does not wobble during operation. The piston rod 603 connects the output end of the electric cylinder 601 and the cross-shaped moving seat 604, transmitting the driving force of the electric cylinder 601 to push the cross-shaped moving seat 604 to move smoothly. The cross-shaped moving seat 604 slides against the extension plate 306 via the U-shaped seat 605, serving as a guide to ensure smooth movement. Simultaneously, it drives the drive arm 607 to rotate via the second sliding inclined groove 606. The U-shaped seat 605 slides between the two sets of extension plates 306, providing precise guidance for the movement of the cross-shaped moving seat 604 and preventing misalignment. When a deviation occurs during movement, the second sliding groove 606 cooperates with the second sliding rod 609 of the drive arm 607 to convert the linear motion of the cross moving seat 604 into the rotational motion of the drive arm 607, ensuring smooth rotation of the drive arm 607. This drives the arc-shaped snap-fit ​​tooth seat 610 to precisely engage. The drive arm 607 rotates around the pin 608, transmitting driving force and causing the arc-shaped snap-fit ​​tooth seat 610 to move closer to or away from the driven gear 502, thus locking or unlocking. The second sliding rod 609 slides with the second sliding groove 606, realizing the conversion of linear motion into rotational motion and ensuring smooth transmission of driving force. The arc-shaped snap-fit ​​tooth seat 610 has an arc-shaped structure that matches the tooth profile of the driven gear 502. When engaged, it has a large contact area and is firmly locked, effectively fixing the driven gear 502 and preventing rotation, thereby fixing the adjusting disc assembly 4 and the expanding hole part 2.

[0030] This invention relates to a variable-diameter pressure-relief drill pipe structure. Its core principle is to achieve flexible adjustment of the drill pipe's borehole diameter through a coordinated logic of "drive adjustment - telescopic diameter change - locking and fixing," adapting to drilling needs of different borehole diameters. Simultaneously, the structural design enables pressure relief. Its overall working principle revolves around three core aspects: "drill bit drilling - borehole diameter change - locking and positioning," with each structure working in concert, as detailed below: (I) Basic Drilling and Connection Positioning Principles: The core drilling function of the drill pipe structure is achieved by the drill bit 1 and the inner pipe 3 at the end.

[0031] (II) Driving and Adjustment Principle of Variable Diameter Hole Reaming: The variable diameter enlargement function is the core of this invention. It is achieved by the enlargement component 2, the adjustment disk assembly 4, the motor 305, and the cross bracket 304 working together. The core logic is to drive the adjustment disk assembly to rotate by the motor, converting the rotational motion into the extension and retraction motion of the enlargement component, thereby adjusting the enlargement diameter.

[0032] 1. Drive trigger: The cross bracket 304 is fixed in the central cavity at the rear end of the inner rod 3 of the last section, which plays a supporting and positioning role. After the motor 305 fixed in the middle of the rear end of the cross bracket 304 is started, it drives the rotating shaft 404 to rotate. The rotating shaft 404 is fixedly connected to the central gear 403 at the front end of the I-shaped turntable 401, which in turn drives the I-shaped turntable 401 (the core component of the adjustment disc assembly 4) to rotate around the cross bracket 304.

[0033] 2. Telescopic and variable diameter: The side wall of the I-shaped turntable 401 is provided with a first sliding groove 402, and the inner end of the slider 201 of the enlarged hole part 2 is provided with a first sliding rod 202, and the two ends of the first sliding rod 202 are slidably connected to the corresponding first sliding groove 402; the slider 201 is inserted through the through groove 302 on the surface of the inner rod 3 of the last section, and the through groove 302 is connected to the central cavity, providing guidance for the telescopic movement of the slider 201.

[0034] When the I-shaped turntable 401 rotates, the first sliding groove 402 and the first sliding rod 202 slide relative to each other. By utilizing the tilt angle of the first sliding groove 402, the slider 201 is pushed to move along the through groove 302 to the outside or inside of the last section inner rod 3, thereby driving the arc-shaped expansion plate 203 at the outer end of the slider 201 to extend and retract synchronously.

[0035] 3. Variable diameter adaptation: When the arc-shaped reaming plate 203 extends outward, the reaming diameter increases; when it retracts inward, the reaming diameter decreases, thereby realizing flexible adjustment of the drill pipe reaming diameter to adapt to drilling needs of different hole diameters; at the same time, the reaming protrusions 205 on the surface of the arc-shaped reaming plate 203 and the inward-retracting arc-shaped inclined plate 204 can enhance the cutting ability during reaming, improve reaming efficiency, and at the same time assist in pressure relief to avoid pressure concentration on the hole wall during drilling.

[0036] (III) Follow-up Assistance and Locking Fixing Principle: 1. Follow-up auxiliary: The cross bracket 304 is equipped with a follow-up gear 5. The front gear 501 of the follow-up gear 5 meshes with the central gear 403. When the central gear 403 rotates under the drive of the motor 305, it will drive the front gear 501 to rotate synchronously, and then drive the rear driven gear 502 to rotate through the rotating rod 503.

[0037] The follower gear 5 helps stabilize the rotation trajectory of the center gear 403, preventing the center gear 403 from deviating or shaking when rotating, ensuring the stability of the adjustment disk assembly 4, and thus ensuring the accuracy of the expansion and contraction of the hole expansion component 2.

[0038] 2. Locking and fixing: After the reamer 2 is adjusted to the required diameter, the locking assembly 6 is activated to fix the adjusting plate assembly 4 and the reamer 2, so as to prevent the reamer diameter from shifting due to vibration during drilling.

[0039] When the electric cylinder 601 is started, the piston rod 603 at the output end pushes the cross-shaped moving seat 604 forward; The U-shaped seat 605 on the cross-shaped movable seat 604 is slidably connected between the two sets of extension plates 306, serving as a guide; The second sliding rod 609 at the rear end of the drive arm 607 slides into the second sliding groove 606 on the side wall of the U-shaped seat 605. When the cross moving seat 604 moves, the second sliding groove 606 slides relative to the second sliding rod 609, pushing the drive arm 607 to rotate around the pin 608, thereby driving the arc-shaped snap-fit ​​tooth seat 610 at the front end of the drive arm 607 to move closer to the driven gear 502 of the follower gear component 5, and finally locking the driven gear 502.

[0040] Since the driven gear 502 meshes with the central gear 403, and the central gear 403 is fixed to the adjusting disk assembly 4, the central gear 403 and the adjusting disk assembly 4 can be indirectly fixed by clamping the driven gear 502, thereby fixing the position of the expanding part 2 and ensuring the diameter is stable during the expanding process.

[0041] (iv) Principle of pressure relief function: The pressure relief function is mainly achieved through the structural design of the reaming component 2 and the through groove 302 of the end section inner rod 3: the reaming protrusions 205 on the surface of the arc-shaped reaming plate 203 and the inwardly tapered arc-shaped inclined plate 204 can disperse the cutting of the hole wall during the reaming process, avoiding local pressure concentration; the through groove 302 on the surface of the end section inner rod 3 is connected to the central cavity, which can guide the pressure and cuttings generated by the hole wall during drilling into the central cavity through the through groove 302 to achieve pressure release, while facilitating the discharge of cuttings, avoiding the accumulation of cuttings that cause drill pipe jamming, and improving the smoothness of drilling and reaming.

[0042] This invention offers flexible and precise diameter adjustment: by driving the adjustment disc assembly to rotate via a motor, the expansion and contraction of the hole-reaming component can be synchronized, allowing for flexible adjustment of the hole diameter to meet drilling requirements of different hole diameters. The diameter adjustment process is smooth, precise, and without jamming. The present invention provides reliable and stable locking: the locking component indirectly fixes the adjusting plate component and the hole-expanding component by clamping the follower gear component, and the locking force is sufficient, which can effectively avoid the hole-expanding diameter deviation caused by drilling vibration and ensure the hole-expanding quality; This invention is easy to assemble, disassemble, and maintain: each structure adopts convenient connection methods such as screw connection, sliding connection, and pin connection, which facilitates the installation, disassembly, and subsequent maintenance of components, and reduces construction and maintenance costs; The present invention has high structural stability: the cross bracket provides stable support for each component, the follower gear assists the rotation of the stabilizing adjustment disk assembly, and all structures work together to avoid shaking and displacement, ensuring stability during drilling and reaming processes and extending the service life of the drill pipe; This invention has wide adaptability: the diameter of the enlarged hole can be flexibly adjusted according to drilling needs, and the drill bit can be easily replaced. It is suitable for drilling scenarios with different geological conditions and different hole diameters, and is highly practical.

[0043] 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 variable diameter pressure relief drill rod structure, comprising an inner rod at the end, characterized in that: A drill bit is connected to the front end of the last section inner rod, and a hole-expanding component is connected to the last section inner rod in a circular, equally spaced telescopic manner. An adjustment disk assembly is rotatably connected to the rear end of the last section inner rod by a cross bracket, and the inner end of the hole-expanding component is slidably connected to the adjustment disk assembly. The motor fixed at the middle of the rear end of the cross bracket is used to drive the rotation of the adjustment plate assembly. The rotation of the adjustment plate assembly realizes the expansion and contraction of the hole expander relative to the inner rod of the last section. The cross bracket is also provided with a follower gear that meshes with the central gear at the front end of the adjustment disc assembly. The front end of the cross bracket is equipped with a locking assembly by an extension plate. The locking assembly fixes the adjustment disc assembly and the enlarged hole component by clamping the follower gear.

2. The variable diameter pressure relief drill rod structure according to claim 1, characterized in that: The drill bit has an external threaded post at the center of its rear end, which is screwed into the internal threaded connection hole at the front end of the last section of the inner rod.

3. The variable diameter pressure relief drill rod structure according to claim 1, characterized in that: The surface of the inner rod of the last section has circular, equally spaced through grooves, which are connected to the central cavity at the rear end of the inner rod of the last section. The hole-expanding component includes a slider inserted through a through slot, an arc-shaped hole-expanding plate connected to the outer end of the slider, and an inwardly tapered arc-shaped inclined plate connected to the side of the arc-shaped hole-expanding plate. The surfaces of the arc-shaped hole-expanding plate and the inwardly tapered arc-shaped inclined plate are provided with hole-expanding protrusions.

4. The variable diameter pressure relief drill rod structure according to claim 3, characterized in that: The inner end of the slider is provided with a first sliding rod; The cross-shaped bracket is supported on the inner wall of the central cavity. The adjustment disk assembly includes an I-shaped turntable. The side wall of the I-shaped turntable is provided with a first sliding groove. The two ends of the first sliding rod are slidably connected to the corresponding first sliding groove.

5. The variable diameter pressure relief drill rod structure according to claim 4, characterized in that: The central gear is fixed in the center at the front end of the I-shaped turntable, and the rotating shaft fixed in the middle of the central gear passes through the cross bracket and is connected to the motor output end.

6. The variable diameter pressure relief drill rod structure according to claim 1, characterized in that: The follower gear component includes a rotating rod movably connected to a cross bracket, a front gear fixed at the front end of the rotating rod, and a driven gear fixed at the rear end of the rotating rod, wherein the front gear meshes with the central gear.

7. The variable diameter pressure relief drill rod structure according to claim 1, characterized in that: The locking assembly includes an electric cylinder, a cross-shaped moving seat fixed at the output end of the electric cylinder, a drive arm slidably connected to the cross-shaped moving seat, and an arc-shaped snap-fit ​​tooth seat fixed at the front end of the drive arm. The drive arm is movably connected between the two corresponding extension plates using a pin shaft.

8. The variable diameter pressure relief drill rod structure according to claim 7, characterized in that: The extension plate is fixed to a cross-shaped fixing seat at its rear end. The electric cylinder is fixed to the rear end of the cross-shaped fixing seat in the center. The piston rod at the output end of the electric cylinder passes through the cross-shaped fixing seat and is connected and fixed to the cross-shaped moving seat. The U-shaped seat on the cross-shaped moving seat slides between the two corresponding sets of extension plates, and the rear end of the drive arm is fixed with a second sliding rod. The side wall of the U-shaped seat is provided with a second sliding groove, and the two ends of the second sliding rod slide into the corresponding second sliding groove.

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