A large-diameter composite segment reamer

Abstract

The application provides a large-diameter composite blade reaming drill bit, belonging to the technical field of reaming drill bits, which comprises a drill bit, a cone is uniformly and circumferentially arranged at the left end of the drill bit, installation grooves are uniformly arranged on the outer circumferential surface of the middle part of the drill bit, and a blade wing is detachably installed in the installation grooves; a limiting groove is arranged on the installation groove in the axial direction of the drill bit, a protruding strip is integrally arranged on the blade wing, the protruding strip is inserted into the limiting groove, and the blade wing is limited in the radial direction of the drill bit, U-shaped cavities are uniformly arranged on the inner circumferential surface of the drill bit, U-shaped limiting seats are slidably arranged in the U-shaped cavities, limiting holes and installation holes are arranged on the surface of the blade wing close to the axis of the drill bit, the left end of the U-shaped limiting seat is inserted into the limiting hole, and the right end of the U-shaped limiting seat is inserted into the installation hole; and the application can solve the problem that the existing replaceable blade wing type drill bit bolt is easily damaged by force, leading to the difficulty in disassembling the blade wing.

Description

Technical Field

[0001] This application relates to the field of reaming drill bit technology, specifically to a large-diameter composite sheet reaming drill bit. Background Technology

[0002] In fields such as mineral resource extraction, engineering geological drilling, and oil and gas well construction, the construction of large-diameter engineering wells places stringent demands on the efficiency and quality of reaming operations. Large-diameter composite reaming drill bits, as core construction tools, directly determine the progress and cost of reaming operations. These drill bits typically use a drill bit body as a base, achieving reaming through cutter wings on the outer periphery. Polycrystalline diamond composite (PDC) drill bits, with their high hardness and wear resistance, have become the core material for the cutting parts of the cutter wings, capable of meeting the cutting requirements of complex strata such as the Cretaceous Huanhe Huachi Formation and the extremely thick Luohe Formation, and are widely used in large-diameter engineering well construction. With the expansion of construction scale and the increase in strata complexity, the industry has placed higher demands on the ease of maintenance, service life, and cost control of large-diameter composite reaming drill bits, and traditional drill bit structures are gradually revealing their insufficient adaptability.

[0003] In actual construction, the blades of large-diameter composite blade reamers, as key components directly in contact with the formation, are subjected to cutting impacts, frictional wear, and formation stress over long periods. This makes them highly susceptible to damage such as composite blade breakage and blade substrate wear, requiring timely replacement or repair to ensure reaming accuracy and efficiency. However, most existing large-diameter composite blade reamers employ a structure where the blades are welded to the drill bit body. When the blades are damaged, on-site repair of the drill bit body is necessary: ​​first, the remaining welded areas are removed, and then new composite blades or blades are re-welded. However, on-site repairs often fail to meet the high-precision process requirements of machining workshops. This results in low positioning accuracy and unstable welding strength in the repaired blades, leading to problems such as blade loosening and uneven wear during subsequent reaming operations. Furthermore, the repair process is time-consuming, severely impacting the project's progress.

[0004] Referring to the Chinese patent document with announcement number CN111502553B, announcement date January 24, 2025, entitled "A Replaceable Blade-Type Large Diameter Composite Sheet Reamer Bit", it includes a drill bit, a limiting device and a positioning device. The limiting device is provided at the bottom outer side of the drill bit and is fixedly connected to the drill bit. The positioning device is provided at the bottom of the limiting device.

[0005] Referring to the above technical solution, the positioning block and the first cutter wing, along with the helical connection between the positioning block and the first screw, the sliding connection between the upper and lower locking blocks, and the helical connection between the second screw and the first cutter wing and the lower locking block, enable the rapid replacement and installation of the cutter wing after hole reaming. However, this solution still has limitations: in actual use, the fixation of the cutter wing and the positioning component relies entirely on the helical connection of the screw. In large-diameter hole reaming operations, the radial impact, axial tension, and rotational torque borne by the cutter wing can easily cause the screw to bend under stress, strip the threads, or break. When the screw is damaged, maintenance personnel cannot disconnect the cutter wing from the drill bit or other auxiliary structures. They can only remove the damaged cutter wing by force (such as cutting or drilling), which is not only cumbersome and time-consuming, but may also cause secondary damage to the drill bit body or positioning component, leading to a decrease in the subsequent cutter wing installation accuracy, or even causing new component damage. Summary of the Invention

[0006] In view of this, this application provides a large-diameter composite blade reaming drill bit, which aims to solve the problem that the bolts of existing replaceable blade drill bits are easily damaged by stress, making blade disassembly difficult.

[0007] To solve the above technical problems, this application provides a large-diameter composite sheet reaming drill bit, including a drill bit, wherein a toothed cone is uniformly rotatably provided on the left end of the drill bit, and a mounting groove is uniformly opened on the outer circumferential surface of the middle part of the drill bit, wherein a cutter wing can be detachably installed inside the mounting groove;

[0008] A limiting groove is formed on the mounting groove along the drill bit axis. A protrusion is integrally formed on the cutter wing, which is inserted into the limiting groove to limit the cutter wing along the radial direction of the drill bit. U-shaped cavities are uniformly formed circumferentially inside the drill bit. The end of the U-shaped cavity opposite to the drill bit axis is connected to the mounting groove. A U-shaped limiting seat is slidably arranged inside each U-shaped cavity. Limiting holes and mounting holes are formed on the surface of the cutter wing near the drill bit axis. The left end of the U-shaped limiting seat is inserted into the limiting hole, and the right end of the U-shaped limiting seat is inserted into the mounting hole. Bolt holes are formed inside each cutter wing, and bolts are installed in the bolt holes. The U-shaped limiting seat and the cutter wing are fixedly connected by bolts.

[0009] By adopting the above technical solution, during the installation of the cutter wing, the protrusion is inserted into the limiting groove, and the inner wall of the mounting groove limits the rotation direction of the cutter wing. The limiting groove restricts the radial movement of the cutter wing through the protrusion. The left end of the U-shaped limiting seat is inserted into the limiting hole, and the right end is inserted into the mounting hole. The bolt passes through the bolt hole to fix the U-shaped limiting seat and the cutter wing, preventing the U-shaped limiting seat from moving radially relative to the cutter wing. The left end of the U-shaped limiting seat cooperates with the limiting hole to restrict the axial movement of the cutter wing. The cutter wing is limited in three directions: rotation, radial, and axial, which effectively improves the stability of the connection between the cutter wing and the drill bit, reduces the probability of the cutter wing loosening or shifting during the hole reaming process, ensures the smooth progress of the hole reaming operation, and avoids excessive bolt stress during the hole reaming process, reducing bolt damage.

[0010] Optionally, a connecting post is rotatably provided inside the right end of the U-shaped limiting seat, the threaded end of the bolt is connected to the internal thread of the connecting post, a hexagonal groove is provided on the end face of the connecting post near the drill bit axis, and a clearance hole corresponding to the hexagonal groove is provided on the U-shaped limiting seat.

[0011] By adopting the above technical solution, the U-shaped limiting seat and the blade are fixed by the threaded connection between the bolt and the connecting column. When the bolt is broken or damaged by external force and cannot be removed from the head, a hexagonal tool is inserted into the hexagonal groove with the help of the clearance hole, and the connecting column is rotated to separate the connecting column from the bolt thread, thereby detaching the connection between the U-shaped limiting seat and the blade. This solves the problem of difficult removal after the bolt is damaged, provides a feasible way to disassemble the blade, reduces the difficulty of blade maintenance or replacement, and saves maintenance time and cost.

[0012] Optionally, each of the U-shaped limiting seats has a sliding cavity inside, and a pin is slidably mounted on the inner wall of each sliding cavity. A collar is fitted on the outer arc surface of the pin, and a return spring is fitted on the right end of each pin. The two ends of the return spring abut against the inner wall of the sliding cavity and the right side wall of the collar, respectively. A slot is opened on the outer arc surface of the end of the connecting column near the drill bit axis. The right end of the pin passes through the side wall of the sliding cavity and is inserted into the inside of the slot. An clearance groove is opened on the left side of the U-shaped limiting seat. The left end of the pin passes through the left side wall of the sliding cavity and extends into the inside of the clearance groove. A push plate is fixedly mounted on the left end of each pin. Through holes are evenly opened circumferentially on the left side wall of the U-shaped cavity, and the through holes correspond to the push plates along the drill bit axis.

[0013] By adopting the above technical solution, during the installation of the blade wing, an external force pushes the push plate, which drives the pin shaft to move to the right, allowing the right end of the pin shaft to insert into the slot of the connecting column, thus restricting the rotation of the connecting column. When it is necessary to rotate the connecting column, the pressure applied to the push plate is released, and the return spring, under its own elastic force, pushes the collar to the left. The collar drives the pin shaft to move to the left, and the right end of the pin shaft disengages from the slot, releasing the restriction on the connecting column and thus restricting its rotation. This ensures that the connecting column does not rotate with the bolt when the bolt is threadedly connected to the connecting column, guaranteeing the stability of the connection. At the same time, the restriction on the connecting column can be easily released, meeting the need for disassembly by rotating the connecting column when the bolt is damaged.

[0014] Optionally, a connecting ring is detachably installed on the drill bit, and a top pin is uniformly fixed on the right side of the connecting ring. The right end of the top pin passes through the through hole and slides in contact with the side of the push plate corresponding to the axial direction.

[0015] By adopting the above technical solution, when the connecting ring is installed on the drill bit, the top pin passes through the through hole and contacts the push plate. The top pin applies a rightward force to the push plate, pushing the push plate to move the pin shaft to the right, so that the right end of the pin shaft is always inserted into the connecting column slot. When it is necessary to release the limiting effect on the connecting column, the connecting ring is removed, and the top pin is removed with the connecting ring, no longer applying force to the push plate. The top pin continuously ensures the limiting effect of the pin shaft on the connecting column, ensuring that the connecting column does not rotate during the hole enlargement operation, further improving the stability of the connection between the bolt and the connecting column. Removing the connecting ring can release the force of the top pin on the push plate, providing convenience for the subsequent rotation of the connecting column. The operation is simple and efficient.

[0016] Optionally, wedge-shaped blocks are evenly arranged circumferentially on the right side of the connecting ring. The wedge-shaped blocks pass through the sidewall of the U-shaped cavity and extend into the interior of the U-shaped cavity. Support blocks are slidably arranged on the inner wall of the U-shaped cavity. The support blocks abut against the surfaces of adjacent wedge-shaped blocks respectively. A compression spring is arranged between the support blocks and the radially corresponding U-shaped limiting seat.

[0017] By adopting the above technical solution, after the connecting ring is installed, the wedge block extends into the U-shaped cavity and abuts against the support block. The inclined structure of the wedge block pushes the support block to slide along the inner wall of the U-shaped cavity, so that the support block applies pressure to the pressure spring. The pressure spring is in a compressed state, and the pressure spring generates an outward elastic force on the U-shaped limit seat, pushing the U-shaped limit seat to maintain the insertion state with the limit hole and mounting hole of the blade wing, ensuring the stable insertion of the U-shaped limit seat and the blade wing. Even if the bolt fails or falls off, it can prevent the U-shaped limit seat from separating from the blade wing and causing the blade wing to fall off, which greatly improves the safety and reliability of the equipment.

[0018] Optionally, the right end of the blade near the drill bit axis is provided with an inclined surface, and the height of the inclined surface in the radial direction of the drill bit is greater than the height of the U-shaped limiting seat in the limiting hole and mounting hole.

[0019] By adopting the above technical solution, when installing the blade wing, the blade wing is pushed into the mounting slot. As the U-shaped limiting seat extends partially out of the mounting slot under the action of the pressure spring, the inclined surface at the right end of the blade wing first contacts the U-shaped limiting seat. As the blade wing continues to be pushed, the interaction force between the inclined surface and the U-shaped limiting seat causes the U-shaped limiting seat to retract into the U-shaped cavity, preventing the U-shaped limiting seat from obstructing the installation of the blade wing. There is no need to manually adjust the position of the U-shaped limiting seat, which simplifies the installation process of the blade wing, reduces the installation difficulty, improves the installation efficiency, and avoids damage caused by hard collisions between components during the installation process.

[0020] Optionally, the left end of the U-shaped limiting seat slides radially with the inner wall of the limiting hole along the drill bit, and the right end of the U-shaped limiting seat has a clearance fit with the inner wall of the mounting hole.

[0021] By adopting the above technical solution, when the cutter wing is subjected to an external force along the drill bit axis, the left end of the U-shaped limiting seat slides against the inner wall of the limiting hole, which can provide axial support and limit the axial movement of the cutter wing; the right end of the U-shaped limiting seat is clearance-fitted with the inner wall of the mounting hole, which reduces the stress on the bolts, avoids damage to the bolts due to excessive external force, and facilitates the replacement of the cutter wing in the future.

[0022] Optionally, the width of the limiting hole is greater than the width of the mounting hole.

[0023] By adopting the above technical solution, when the cutter wing is axially slidably installed in the mounting groove, the left end of the U-shaped limiting seat may enter the mounting hole. Since the width of the limiting hole is greater than the width of the mounting hole, the left end of the U-shaped limiting seat slides radially with the inner wall of the limiting hole along the drill bit, and the left end of the U-shaped limiting seat cannot enter the mounting hole, ensuring that the cutter wing can slide smoothly to the installation position, ensuring the smoothness of the cutter wing installation process, and further improving the installation efficiency.

[0024] Optionally, the drill bit has a coolant pipe inside, and the outlet of the coolant pipe is respectively configured to cooperate with the cutting surface of the blade.

[0025] By adopting the above technical solution, during the hole reaming operation, the external cooling system delivers coolant to the coolant pipe. The coolant flows inside the coolant pipe and is sprayed out from the outlet corresponding to the blade, directly acting on the cutting part of the blade, carrying away the heat generated by the blade during cutting, and at the same time washing away the rock chips generated during the cutting process, ensuring the efficiency and quality of the hole reaming operation.

[0026] Optionally, each bolt hole is equipped with an elastic sealing plug to prevent mud and rock cuttings from entering the bolt hole during the hole enlargement operation.

[0027] By adopting the above technical solution, the elastic sealing plug installed in the bolt hole can isolate the bolt hole from the external environment, prevent impurities such as mud and rock chips generated during the hole enlargement operation from entering the bolt hole, avoid impurities adhering to the bolt surface or clogging the bolt hole, protect the bolt and bolt hole from impurity corrosion, prevent the bolt from rusting or getting stuck due to impurities, ensure the smoothness of bolt disassembly and installation, and at the same time avoid impurities clogging the bolt hole, which would prevent normal operation during subsequent maintenance, reduce maintenance difficulty, and extend the service life of the components.

[0028] In summary, compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0029] 1. When the cutter blade is damaged by long-term cutting, such as wear or cracking, there is no need to perform complicated cutting and disassembly operations. Simply remove the elastic sealing plug, unscrew the bolts, and push the U-shaped limit seat away from the limit hole and the mounting hole. The cutter blade can then be removed from the mounting slot for replacement. This detachable structure greatly shortens maintenance time, reduces the risk of damage to the drill bit body caused by welding and disassembly, and reduces the overall equipment replacement cost caused by the damage of a single component, thereby improving the economic efficiency of the equipment.

[0030] 2. The inner wall of the mounting groove limits the rotation direction of the blade. The limiting groove restricts the radial movement of the blade through the convex strip. The sliding fit between the left end of the U-shaped limiting seat and the limiting hole restricts the axial movement of the blade. Comprehensive limiting is formed in three dimensions: rotation, radial, and axial. On this basis, the bolt only needs to bear the fixing function between the U-shaped limiting seat and the blade, without having to bear the radial or axial impact force or rotational torque generated during the hole enlargement operation. This significantly reduces the probability of bolt breakage, stripping, or other damage during the hole enlargement process and extends the service life of the bolt.

[0031] 3. The wedge block pushes the support block, causing the support block to exert a continuous radial force on the U-shaped limiting seat through the pressure spring. This ensures that the U-shaped limiting seat remains in contact with the limiting hole and mounting hole of the cutter wing. Even if the bolts loosen or fall off due to vibration or impact during drilling, the spring force can still maintain the limiting effect of the U-shaped limiting seat on the cutter wing, preventing the U-shaped limiting seat from separating from the cutter wing and thus preventing the cutter wing from falling out of the mounting groove. This dual protection design significantly reduces the safety risks of equipment failure and drill jamming caused by cutter wing detachment, improving the reliability and safety of the equipment under complex working conditions.

[0032] 4. When the bolt is damaged, first remove the connecting ring to disengage the top pin from the push plate. The return spring will then move the pin to the left under its elastic force, releasing the rotation limit on the connecting column. Then, remove the support block and the pressure spring. Through the clearance hole on the U-shaped limit seat, insert the hexagonal tool into the hexagonal groove on the end face of the connecting column. Rotating the connecting column will separate it from the bolt thread, thereby disconnecting the U-shaped limit seat from the blade. This avoids the problem of secondary damage to the drill bit or blade caused by the need for violent disassembly (such as cutting or drilling) after bolt damage, ensuring that the blade can still be disassembled efficiently and safely even in the case of bolt failure, providing a reliable solution for equipment maintenance. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a large-diameter composite sheet reaming drill bit according to this application;

[0034] Figure 2 This is a cross-sectional planar structural diagram of the drill bit of this application;

[0035] Figure 3 For this application Figure 2 Schematic diagram of the structure of region A in the middle;

[0036] Figure 4 This is a schematic diagram of the connecting ring structure of this application;

[0037] Figure 5 This is a schematic diagram of the U-shaped limiting seat of this application;

[0038] Figure 6 This is a structural schematic diagram of the connecting column in this application;

[0039] Figure 7 This is a schematic diagram of the structure of the pin, collar, and push plate in this application.

[0040] Explanation of reference numerals in the attached drawings: 1. Drill bit; 101. Mounting groove; 102. Limiting groove; 103. U-shaped cavity; 104. Through hole; 2. Gear wheel; 3. Cutting wing; 31. Limiting hole; 32. Mounting hole; 33. Bolt hole; 4. Raised bar; 5. U-shaped limiting seat; 51. Sliding cavity; 52. Clearance hole; 53. Clearance groove; 6. Bolt; 7. Connecting post; 71. Slot; 72. Hexagonal groove; 8. Pin; 9. Collar; 10. Return spring; 11. Push plate; 12. Connecting ring; 13. Top pin; 14. Wedge block; 15. Support block; 16. Compression spring; 17. Inclined surface; 18. Coolant pipe; 19. Elastic sealing plug. Detailed Implementation

[0041] The following will be described in conjunction with embodiments of this application. Figures 1-7The technical solutions of the embodiments of this application are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of this application are within the scope of protection of this application.

[0042] Reference Figure 1 and Figure 2 This embodiment provides a large-diameter composite sheet reaming drill bit, including a drill bit 1, a roller cone 2, a cutter wing 3, and a coolant pipe 18. The roller cone 2 is circumferentially and evenly rotatably arranged at the left end of the drill bit 1. The middle outer circumferential surface of the drill bit 1 is evenly provided with mounting grooves 101. The cutter wing 3 can be detachably installed inside the mounting grooves 101. When the drill bit 1 is drilling, the cutter wing 3 rotates synchronously to ream the hole. The coolant pipe 18 is evenly arranged inside the drill bit 1. The inlet of the coolant pipe 18 is connected to the drill rod channel, and the outlet faces the cutting surface of the cutter wing 3.

[0043] During use, drill bit 1 is fixedly connected to the drill rod of an external drilling machine (not shown in the attached diagram). The drill rod drives drill bit 1 to rotate and drill a hole. At the same time, the roller cone 2 rotates due to contact with the rock at the bottom of the hole, and the tooth extrusion cuts to form the basic hole diameter. As drill bit 1 rotates, cutter blade 3 rotates synchronously, and the high hardness of the cutter blade 3 cuts the hole wall to achieve hole enlargement. The water-based coolant containing rust inhibitor is transported to each coolant pipe 18 through the drill rod channel by the external cooling system, and sprayed out from the outlet to dissipate heat from the cutter blade 3, while washing away rock cuttings.

[0044] Reference Figure 1 , Figure 2 and Figure 3A limiting groove 102 is formed on the mounting groove 101 along the axis of the drill bit 1. A protrusion 4 is integrally formed on the cutter wing 3 and is inserted into the limiting groove 102. U-shaped cavities 103 are evenly formed in the circumferential direction inside the drill bit 1. The end of the U-shaped cavity 103 away from the axis of the drill bit 1 is connected to the mounting groove 101. U-shaped limiting seats 5 are slidably arranged inside the U-shaped cavity 103. Limiting holes 31 and mounting holes 32 are formed on the surface of the cutter wing 3 near the axis of the drill bit 1. The right end of the U-shaped limiting seat 5 is inserted into the interior of the mounting hole 32 and is clearance-fitted with the inner wall of the mounting hole 32. The mounting hole 32 is used to cooperate with the U-shaped limiting seat 5 for initial positioning. Bolt holes 33 are provided inside each of the cutter wings 3, and bolts 6 are installed inside the bolt holes 33. The U-shaped limiting seat 5 and the cutter wings 3 are fixedly connected by bolts 6. The bolts 6 prevent the U-shaped limiting seat 5 from moving radially relative to the cutter wings 3 along the drill bit 1, ensuring the stability of the cutter wings 3 installation. The left end of the U-shaped limiting seat 5 is inserted into the limiting hole 31 and slides radially against the inner wall of the limiting hole 31. The side of the left end of the U-shaped limiting seat 5 abuts against the inner wall of the limiting hole 31 in the axial direction of the drill bit 1, allowing the cutter wings 3 to move radially. The drill bit 1's axial direction serves as a support and limiter, preventing the cutter blade 3 from moving axially along the drill bit 1. The limiting hole 31 is used to restrict the cutter blade 3's movement along the drill bit 1's axial direction, while also preventing excessive stress on the bolt 6 during the reaming process, reducing the probability of bolt 6 damage. Each bolt hole 33 is equipped with an elastic sealing plug 19 to prevent mud from clogging the bolt holes 33. During the reaming process, the cutter blade 3 is inserted into the mounting groove 101. The inner wall of the mounting groove 101 limits the cutter blade 3's movement in the rotation direction of the drill bit 1. The limiting groove 102, through the protrusion 4, limits the cutter blade 3's movement radially along the drill bit 1. The U-shaped limiting seat 5 provides directional control. When the blade 3 is subjected to a large external force and tends to move along the axis of the drill bit 1, the left end of the U-shaped limiting seat 5 slides radially with the inner wall of the limiting hole 31 along the drill bit 1, and there is a certain gap between the right end of the U-shaped limiting seat 5 and the inner wall of the mounting hole 32. The left end of the U-shaped limiting seat 5 supports and limits the blade 3 in the axial direction of the drill bit 1, thus preventing the right end of the U-shaped limiting seat 5 from being subjected to excessive external force and causing damage to the bolt 6. Through the above structure, the reaming drill bit 1 is limited from three directions, effectively ensuring the stability of the connection between the blade 3 and the drill bit 1.

[0045] Reference Figure 3 A connecting post 7 is rotatably installed inside the right end of the U-shaped limiting seat 5. The threaded end of the bolt 6 is connected to the internal thread of the connecting post 7. A hexagonal groove 72 is provided on the end face of the connecting post 7 near the axis of the drill bit 1. A clearance hole 52 corresponding to the hexagonal groove 72 is provided on the U-shaped limiting seat 5. When the bolt 6 breaks or is otherwise damaged due to excessive external force during the hole enlargement process, it cannot be removed normally from the head of the bolt 6. At this time, by inserting a hexagonal wrench into the hexagonal groove 72 and rotating the connecting post 7, the U-shaped limiting seat 5 is separated from the bolt 6, and the blade 3 is disassembled.

[0046] To ensure proper connection between bolt 6 and connecting post 7 and prevent connecting post 7 from rotating with bolt 6, a sliding cavity 51 is provided inside the U-shaped limiting seat 5. Pins 8 are slidably mounted on the inner wall of the sliding cavity 51, and collars 9 are fitted onto the outer arc surface of the pins 8. Return springs 10 are fitted onto the right end of each pin 8, with both ends of the return springs 10 abutting against the inner wall of the sliding cavity 51 and the right side wall of the collar 9, respectively. Slots 71 are provided on the outer arc surface of the end of the connecting post 7 closest to the axis of drill bit 1 (see reference). Figure 3 and Figure 6 The right end of the pin 8 passes through the side wall of the slide cavity 51 and is inserted into the inside of the slot 71 under the action of external force, limiting the connection post 7 and preventing it from rotating freely.

[0047] Reference Figure 3 and Figure 5 During the threaded connection between bolt 6 and connecting post 7, connecting post 7 will drive U-shaped limiting seat 5 to move from a position close to the axis of drill bit 1 to a position away from the axis of drill bit 1. During this process, in order to ensure that pin 8 can always limit the connecting post 7, a relief groove 53 is provided on the left side of U-shaped limiting seat 5. The left end of pin 8 passes through the left side wall of sliding cavity 51 and extends into the interior of relief groove 53. A push plate 11 is fixedly provided on the left end of pin 8 (see reference). Figure 7 The left side wall of the U-shaped cavity 103 has through holes 104 evenly distributed around its circumference. These through holes 104 correspond to the push plate 11 along the axis of the drill bit 1. A connecting ring 12 is detachably mounted on the drill bit 1 via fastening bolts. Top pins 13 are evenly fixed around the right side of the connecting ring 12. The right ends of the top pins 13 pass through the through holes 104 and slide in contact with the side of the push plate 11 corresponding to the axis of the drill bit 1. The top pins 13 push the pin shaft 8 to the right via the push plate 11, ensuring that the right end of the pin shaft 8 is always inserted into the slot 71, thus limiting the position of the connecting post 7. When it is necessary to disassemble the bolt 6 by rotating the connecting post 7, the connecting ring 12 is first removed using screws. The moving top pin 13 moves to the left. At this time, the top pin 13 no longer pushes the push plate 11. The initial distance between the left side wall of the U-shaped cavity 103 and the push plate 11 along the axis of the drill bit 1 is not less than the maximum stroke of the pin 8 (i.e., the axial movement distance of the pin 8 from being fully inserted into the slot 71 to being fully disengaged from the slot 71). The return spring 10 drives the collar 9 and the pin 8 to move to the left through its own elastic force. The push plate 11 moves to the left along the clearance groove 53. Because the initial distance is sufficient, the push plate 11 will not collide with the left side wall of the U-shaped cavity 103, ensuring that the right end of the pin 8 is completely disengaged from the slot 71. Then, the connecting post 7 is rotated by inserting a hexagonal wrench into the inside of the hexagonal groove 72 to separate the connecting post 7 and the bolt 6.

[0048] Reference Figure 3 and Figure 4Wedge-shaped blocks 14 are evenly arranged circumferentially on the right side of the connecting ring 12. Each wedge-shaped block 14 passes through the sidewall of the U-shaped cavity 103 and extends into the interior of the U-shaped cavity 103. Support blocks 15 are slidably arranged on the inner wall of the U-shaped cavity 103. The side of the wedge-shaped block 14 closest to the support block 15 is an inclined surface, and the side of the support block 15 closest to the wedge-shaped block 14 is a mating surface matching the inclined surface of the wedge-shaped block 14. The support blocks 15 abut against the inclined surfaces of adjacent wedge-shaped blocks 14. The support blocks 15 and radially corresponding... A pressure spring 16 is provided between the U-shaped limiting seats 5. The wedge block 14 supports the support block 15 in the radial direction of the drill bit 1. The support block 15 supports the U-shaped limiting seat 5 in the radial direction of the drill bit 1 through the pressure spring 16. When the bolt 6 fails or falls off due to vibration during drilling, the elastic force of the pressure spring 16 can still keep the U-shaped limiting seat 5 inserted in the limiting hole 31, so as to prevent the U-shaped limiting seat 5 from separating from the blade 3 and causing the blade 3 to fall off.

[0049] Reference Figure 3 The cutter wing 3 has a bevel 17 on its right end near the axis of the drill bit 1. The height of the bevel 17 in the radial direction of the drill bit 1 is greater than the height of the U-shaped limit seat 5 in the portion of the limit hole 31 and the mounting hole 32. The height of the U-shaped limit seat 5 in the portion of the limit hole 31 and the mounting hole 32 is equal. During the process of installing the cutter wing 3 into the mounting groove 101, the protrusion 4 is inserted into the interior of the limit groove 102. Then, the cutter wing 3 is pushed to the right. Because the U-shaped limit seat 5 extends into the interior of the mounting groove 101 under the elastic force of the pressure spring 16, it will hinder the sliding of the cutter wing 3 along the axis of the drill bit 1. During the sliding process, the bevel 17 first contacts the left end of the U-shaped limit seat 5. As the cutter wing 3 moves to the right, the bevel 17 applies radial pressure to the U-shaped limit seat 5. The force component on the side (close to the axis of drill bit 1) overcomes the elastic force of the pressure spring 16 and squeezes the U-shaped limiting seat 5 into the U-shaped cavity 103 until the cutter wing 3 slides to the installation position. At this time, the U-shaped limiting seat 5 corresponds to the limiting hole 31 and the mounting hole 32 in the radial position of drill bit 1, respectively. The U-shaped limiting seat 5 is reset under the elastic force of the pressure spring 16, so that the right end of the U-shaped limiting seat 5 is inserted into the inside of the mounting hole 32 and the left end of the U-shaped limiting seat 5 is inserted into the inside of the limiting hole 31, completing the initial positioning of the cutter wing 3. The width of the limiting hole 31 is greater than the width of the mounting hole 32 to ensure that the left end of the U-shaped limiting seat 5 will not enter the inside of the limiting hole 31 during the process of the cutter wing 3 sliding to the right inside the mounting groove 101, thus ensuring the smooth installation of the cutter wing 3.

[0050] The implementation principle of a large-diameter composite sheet reaming drill bit in this application embodiment is as follows:

[0051] First, the U-shaped limiting seat 5 is slidably set in the U-shaped cavity 103 inside the drill bit 1. Then, a pressure spring 16 is installed on the support block 15, and the support block 15 is placed inside the U-shaped cavity 103, so that the two ends of the pressure spring 16 abut against the support block 15 and the radially corresponding U-shaped limiting seat 5, respectively. The top pin 13 is aligned with the through hole 104, and the connecting ring 12 is detachably connected to the left side wall of the drill bit 1 by a fastening bolt (the left side wall of the drill bit 1 has a threaded hole that matches the fastening bolt). During this process, the wedge block 14 is inserted into the U-shaped cavity 103 and pushes the support block 15 away from the axis of the drill bit 1, providing radial support for the support block 15. The top pin 13 pushes the push plate 11 to the right, and the push plate 11 drives the pin 8 to move to the right and insert into the slot 71, restricting the rotation of the connecting post 7. At this time, the pin 8 drives the collar 9 to move to the right and compress the return spring 10.

[0052] When installing the cutter wing 3, first insert the protrusion 4 of the cutter wing 3 into the limiting groove 102 of the mounting groove 101, and then push the cutter wing 3 to the right. Because the U-shaped limiting seat 5 partially extends out of the mounting groove 101 under the action of the pressure spring 16, the inclined surface 17 of the cutter wing 3 near the axis of the drill bit 1 will squeeze the U-shaped limiting seat 5, causing it to retract into the U-shaped cavity 103 until the cutter wing 3 slides into place. Under the reset action of the pressure spring 16, the left end of the U-shaped limiting seat 5 inserts into the limiting hole 31 and the right end inserts into the mounting hole 32. Bolt 6 is inserted into bolt hole 33 and threadedly connected to connecting post 7. At this time, connecting post 7 will not rotate due to the restriction of pin 8. Rotating bolt 6 achieves the connection and fixation between U-shaped limit seat 5 and cutter wing 3. An elastic sealing plug 19 is installed at the opening of bolt hole 33. The elastic sealing plug 19 is made of wear-resistant rubber and is installed at the opening of bolt hole 33 by interference fit. When removing it, it can be pulled out with the help of tools to protect bolt hole 33 and prevent mud and rock cuttings from clogging bolt hole 33. During the hole enlargement process, drill bit 1 is driven to rotate by external drill rod. The roller cone 2 contacts the rock at the bottom of the hole and rotates. The tooth extrusion cuts to form the basic hole diameter. At the same time, cutter wing 3 rotates with drill bit 1 to cut the hole wall to enlarge the hole. The external cooling system delivers water-based coolant to coolant pipe 18 through drill rod channel and sprays it out from the outlet to dissipate heat and wash away rock cuttings from cutter wing 3.

[0053] When it is necessary to disassemble the blade wing 3 and the bolt 6 can be operated normally, remove the elastic sealing plug 19, unscrew the bolt 6 directly, and use a screwdriver or other rod-shaped tool to insert into the bolt hole 33 to press the connecting post 7 (the inner diameter of the threaded hole in the center of the connecting post 7 is smaller than the inner diameter of the lower section of the bolt hole 33 near the connecting post 7; this hole diameter difference design allows the screwdriver to pass smoothly through the lower section of the bolt hole 33 and directly abut against the end face of the connecting post 7 and apply downward pressure, thereby pushing the U-shaped limiting seat 5 to retract into the U-shaped cavity 103), so that the U-shaped limiting seat 5 separates from the blade wing 3. At the same time, push the blade wing 3 to the left, and the blade wing 3 can be removed from the mounting slot 101. If bolt 6 breaks or its threads are deformed and damaged due to excessive force during the hole enlargement process, making normal disassembly impossible, then the connecting ring 12 must be removed first. This prevents the top pin 13 from pushing the push plate 11. The return spring 10 then drives the collar 9 and pin 8 to move to the left through its elastic force. The right end of the pin 8 separates from the slot 71 of the connecting post 7, releasing the restriction on the connecting post 7. The support block 15 and the pressure spring 16 are then removed from the left end opening of the U-shaped cavity 103 (which engages with the wedge block 14). At this point, sufficient operating space is formed within the U-shaped cavity 103, and the diameter of the clearance hole 52 is not less than the nominal diameter of the hex wrench. The hex wrench is then inserted through the clearance hole 52 into the hexagonal groove 72 of the connecting post 7 and rotated to separate the connecting post 7 from the bolt 6, thereby releasing the connection between the U-shaped limit seat 5 and the blade 3, ultimately achieving the disassembly of the blade 3. This process ensures that the blade 3 can still be replaced or maintained safely and efficiently even if bolt 6 fails.

[0054] Furthermore, in the description of this application, the terms "installation", "connection", "linking", and "setting" should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

Claims

1. A large-diameter composite sheet reaming drill bit, comprising a drill bit, wherein a toothed cone is circumferentially and rotatably disposed at the left end of the drill bit, and mounting grooves are uniformly formed on the outer circumferential surface of the middle part of the drill bit, wherein cutting blades are detachably mounted inside the mounting grooves, characterized in that: A limiting groove is formed on the mounting groove along the drill bit axis. A protrusion is integrally formed on the cutter wing. The protrusion is inserted into the limiting groove to limit the cutter wing along the radial direction of the drill bit. U-shaped cavities are uniformly formed in the circumferential direction of the drill bit. The end of the U-shaped cavity opposite to the drill bit axis is connected to the mounting groove. A U-shaped limiting seat is slidably arranged inside the U-shaped cavity. A limiting hole and a mounting hole are formed on the surface of the cutter wing near the drill bit axis. The left end of the U-shaped limiting seat is inserted into the limiting hole, and the right end of the U-shaped limiting seat is inserted into the mounting hole. Bolt holes are formed inside the cutter wing, and bolts are installed in the bolt holes. The U-shaped limiting seat and the cutter wing are fixedly connected by bolts. A connecting post is rotatably provided inside the right end of the U-shaped limiting seat. The threaded end of the bolt is connected to the internal thread of the connecting post. A hexagonal groove is provided on the end face of the connecting post near the drill bit axis. A clearance hole corresponding to the hexagonal groove is provided on the U-shaped limiting seat. Each U-shaped limiting seat has a sliding cavity inside. A pin is slidably mounted on the inner wall of each sliding cavity. A collar is fitted on the outer arc surface of the pin. A return spring is fitted on the right end of each pin. The two ends of the return spring abut against the inner wall of the sliding cavity and the right side wall of the collar, respectively. A slot is opened on the outer arc surface of the end of the connecting column near the drill bit axis. The right end of the pin passes through the side wall of the sliding cavity and is inserted into the inside of the slot. A clearance groove is opened on the left side of the U-shaped limiting seat. The left end of the pin passes through the left side wall of the sliding cavity and extends into the inside of the clearance groove. A push plate is fixedly mounted on the left end of each pin. Through holes are evenly opened circumferentially on the left side wall of the U-shaped cavity. The through holes correspond to the push plates along the drill bit axis. A connecting ring is detachably installed on the drill bit. Top pins are evenly fixed on the right side of the connecting ring. The right end of the top pin passes through the through hole and slides in contact with the side of the push plate corresponding to the axial direction.

2. The large-diameter composite sheet reaming drill bit according to claim 1, characterized in that: The right side of the connecting ring is uniformly provided with wedge-shaped blocks in the circumferential direction. The wedge-shaped blocks all pass through the side wall of the U-shaped cavity and extend into the interior of the U-shaped cavity. The inner wall of the U-shaped cavity is slidably provided with support blocks. The support blocks abut against the surfaces of adjacent wedge-shaped blocks respectively. A pressure spring is provided between the support blocks and the radially corresponding U-shaped limiting seats.

3. The large-diameter composite sheet reaming drill bit according to claim 1, characterized in that: The cutter blade has an inclined surface on its right end near the drill bit axis. The height of the inclined surface in the radial direction of the drill bit is greater than the height of the U-shaped limit seat in the limit hole and mounting hole.

4. The large-diameter composite sheet reaming drill bit according to claim 3, characterized in that: The left end of the U-shaped limiting seat slides radially with the inner wall of the limiting hole along the drill bit, and the right end of the U-shaped limiting seat has a clearance fit with the inner wall of the mounting hole.

5. A large-diameter composite sheet reaming drill bit according to claim 4, characterized in that: The width of the limiting hole is greater than the width of the mounting hole.

6. The large-diameter composite sheet reaming drill bit according to claim 1, characterized in that: The drill bit has a coolant pipe inside, and the outlet of the coolant pipe is respectively set to match the cutting surface of the blade.

7. A large-diameter composite sheet reaming drill bit according to claim 1, characterized in that: Each bolt hole is equipped with an elastic sealing plug to prevent mud and rock cuttings from entering the bolt hole during the hole enlargement operation.

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