A tong body assembly for gripping a drill pipe and an iron roughneck

Abstract

This invention discloses a clamp assembly for holding drill pipes, including a mounting frame, a main clamp, a back clamp, and a centering mechanism. The mounting frame has mounting grooves; both the main clamp and the back clamp are embedded in the mounting grooves, with the clamping centers of the main clamp and the back clamp aligned. The main clamp and the back clamp are rotatably connected to the mounting frame. The back clamp has a pair of jaw seats symmetrically arranged via a clamping cylinder. The centering mechanism includes a pair of push arms, with the roots of the two push arms hinged and equipped with return torsion springs to form a V-shaped push-center pressure groove between the two push arms. The centering mechanism is located on the back clamp, and the centerline of the push-center pressure groove points to the clamping center of the back clamp. The two push arms correspond to the two jaw seats, and when the jaw seats approach each other, they can compress the back side of the corresponding push arms, thereby reducing the included angle of the push-center pressure groove. This solves the problem of drill pipes deviating from the clamping center of the back clamp. It also solves the problem of slippage and instability during drill pipe clamping in existing drill pipe clamping systems, which affects the smooth operation of attaching and detaching.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling technology, specifically to a clamp assembly for holding drill pipes and a metal drill bit. Background Technology

[0002] During oil drilling and well workover, drill pipe coupling and uncoupling operations are essential. Since each section of drill pipe is coaxially connected by a threaded joint, when coupling, the drill pipes must be drilled into the wellhead one by one. After the previous drill pipe is drilled in, the main tongs and back tongs of the driller's tongs assembly clamp the next drill pipe to the previous drill pipe, making them coaxial. Then, the relative rotation of the main tongs and back tongs connects the next drill pipe to the previous drill pipe. Conversely, when uncoupling, the same method is used to clamp and fix the two sections of drill pipe, and then rotate them relative to each other to remove the drill pipe.

[0003] In practice, existing iron drill operators typically use a moving mechanism to move the tongs assembly to the wellhead position during uncoupling operations. They then adjust the positions of the main tongs and back tongs using the moving mechanism to align their clamping centers with the drill pipe before clamping and fixing them. However, the moving mechanism can only be adjusted remotely, resulting in low precision and adaptability. This can easily cause the drill pipe to deviate from the clamping center of the main tongs or back tongs, leading to slippage and instability, which seriously affects the smooth progress of drill pipe uncoupling operations. Summary of the Invention

[0004] The first objective of this invention is to provide a clamp assembly for holding drill pipes, which can solve the problem of drill pipes deviating from the clamping center of the back clamp.

[0005] The second objective of this invention is to provide a drill bit that solves the problem of slippage and instability in existing drill bit clamps, which affects the smooth operation of attaching and detaching the clamps.

[0006] This invention is achieved through the following technical solution:

[0007] A clamp assembly for clamping drill pipe includes: a mounting frame with a mounting groove; a main clamp and a back clamp, both of which are embedded in the mounting groove, the main clamp being located directly above the back clamp, the clamping centers of the main clamp and the back clamp being aligned, the main clamp and the back clamp being used to clamp two sections of drill pipe for attaching and unattaching respectively; the back clamp is fixedly connected to the mounting frame, and the main clamp is rotatably connected to the mounting frame, with the rotating shaft collinear with the line connecting the two clamping centers; the back clamp is symmetrically provided with clamping cylinders. The jaws are designed to allow them to move closer or further apart synchronously. A centering mechanism is included, comprising a pair of pushing arms. The roots of the two pushing arms are hinged and fitted with return torsion springs to form a V-shaped pushing groove between them. The centering mechanism is located on the back jaws, and the centerline of the pushing groove points to the clamping center of the back jaws. The two pushing arms correspond to the two jaws respectively. When the jaws approach each other, they can compress the back side of the corresponding pushing arm, thereby reducing the included angle of the pushing groove.

[0008] Optionally, the jaw seat is recessed inward on the side facing the clamping center, and jaws are installed in the middle of the jaw seat, with the jaws arranged parallel to the axis of the clamped drill rod.

[0009] Optionally, the jaw holder is provided with two rows of positioning pins to form a positioning space between the two rows of positioning pins. The straight line of each row of positioning pins is parallel to the axis of the clamped drill rod. The positioning pins are slidably connected to the jaw holder along the axial direction by springs. When the springs are in their natural state, the outer end of the positioning pins protrudes out of the jaws.

[0010] Optionally, the back arc surface of the centering arm of the centering mechanism abuts against one side of the jaw seat, and the jaw seat pushes the centering arm to move.

[0011] Optionally, the jaw holder has a jaw protruding in the middle, and the jaw has a distribution of jaw teeth arranged in an arc. The apex of each jaw tooth is located in an arc surface, which can increase the number of jaw teeth in contact with the drill pipe.

[0012] Optionally, the centering mechanism further includes a limiting frame, the roots of the two centering arms are located inside the limiting frame, and the hinge shaft is rotatably connected to the limiting frame. When the reset torsion spring is in its natural state, the back side of the root of the centering arm abuts against and presses against the inner frame of the limiting frame.

[0013] Optionally, the inner side of the push arm is configured as an arc surface, and the generatrix of the inner side of the push arm is arranged parallel to the axis of the clamped drill rod.

[0014] Optionally, the mounting frame includes a fixed frame and an adjusting frame, the adjusting frame being hinged to the fixed frame, and the straight line of the hinge axis being parallel to the moving direction of the jaws; a buffer cylinder is hinged between the fixed frame and the adjusting frame, the buffer cylinder being able to buffer the impact and vibration when the adjusting frame rotates with the hinge axis as the axis to the fixed frame.

[0015] Optionally, the fixed frame hinge has a front connecting rod and a rear connecting rod, and the front connecting rod and the rear connecting rod are respectively hinged to the adjusting frame to form a quadrilateral hinge structure; the length of the front connecting rod is equal to the length of the rear connecting rod; the line where the buffer cylinder is located is parallel to the horizontal direction or at an acute angle.

[0016] A drill bit assembly includes: a clamping body assembly for clamping drill rods (as described above); a telescopic mechanism, one end of which is connected to the clamping body assembly for clamping drill rods; a lifting mechanism, the lifting mechanism being connected to the end of the telescopic mechanism away from the clamping body assembly for clamping drill rods; and a rotating mechanism, the rotating mechanism being connected to the lifting mechanism to enable the lifting mechanism to rotate horizontally.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0018] This invention provides a clamp assembly for holding drill pipes. By providing a mounting bracket, the assembly can be connected to a moving mechanism while simultaneously providing a mounting base for the main clamp and back clamp. The main clamp and back clamp respectively clamp two sections of the drill pipe for attaching and unattaching. Furthermore, both are rotatably connected to the mounting bracket to perform attaching and unattaching operations. In addition, a centering mechanism is provided in the back clamp, including a pair of push arms. The root hinges of the two push arms form a V-shaped push-center pressure groove, restricting the centerline of the push-center pressure groove from pointing to the clamping center of the back clamp. When the drill pipe deviates from the clamping center of the back clamp during clamping, [the mechanism prevents this]. The two push arms are symmetrically squeezed inward, reducing the angle of the V-shaped push-center pressure groove between them. This allows the inner side of the push arms to squeeze the drill rod towards the clamping center of the back tong. Based on this, the back tong is clamped by using a clamping cylinder to push a pair of jaws closer together. Furthermore, the pair of push arms are aligned with the pair of jaws, so that when the jaws approach each other, they can squeeze the back side of the corresponding push arms. This automatically reduces the angle of the push-center pressure groove during the process of the jaws approaching each other, pushing the drill rod to the clamping center of the back tong before clamping, thus solving the problem of the drill rod deviating from the clamping center of the back tong. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0020] Figure 1This is a schematic diagram of a clamp assembly for holding a drill pipe provided in an embodiment of the present invention;

[0021] Figure 2 A side sectional view of a clamp assembly for holding drill pipe provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a mounting bracket for a clamping assembly for holding drill pipes, provided in an embodiment of the present invention.

[0023] Figure 4 A schematic diagram of the back clamp of the clamp body assembly for clamping drill pipe provided in an embodiment of the present invention;

[0024] Figure 5 A schematic diagram of the jaws of a clamping body assembly for clamping drill pipe provided in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the centering mechanism of the clamp body assembly for holding drill pipe provided in an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of an iron driller provided in an embodiment of the present invention.

[0027] The attached diagram shows the markings and corresponding component names:

[0028] 10-Mounting bracket; 11-Mounting slot; 12-Fixing bracket; 13-Adjusting bracket; 131-Buffer cylinder; 14-Front connecting rod; 15-Rear connecting rod; 20-Main clamp; 30-Back clamp; 31-Jaw jaw seat; 32-Positioning pin; 33-Clamping cylinder; 34-Jaw jaw; 341-Jaw jaw; 40-Push arm; 41-Reset torsion spring; 42-Push pressure groove; 43-Limit frame; 50-Telescopic mechanism; 60-Lifting mechanism; 70-Rotation mechanism. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0030] Please refer to Figures 1 to 6This embodiment provides a clamp assembly for clamping drill pipes, including a mounting frame 10 with a mounting groove 11; and a main clamp 20 and a back clamp 30, both of which are embedded in the mounting groove 11. The main clamp 20 is located directly above the back clamp 30, and the clamping centers of the main clamp 20 and the back clamp 30 are aligned. The main clamp 20 and the back clamp 30 are used to clamp two sections of drill pipe for attaching and detaching, respectively. The back clamp 30 is fixedly connected to the mounting frame 10, and the main clamp 20 is rotatably connected to the mounting frame, with the rotating shaft collinear with the line connecting the two clamping centers. The back clamp 30 is connected to a clamping cylinder. A pair of jaw seats 31 are symmetrically arranged so that the two jaw seats 31 can move closer or further apart synchronously; the third includes a centering mechanism, which includes a pair of pushing arms 40. The roots of the two pushing arms 40 are hinged and equipped with a return torsion spring 41 so that a V-shaped pushing pressure groove 42 is formed between the two pushing arms 40. The centering mechanism is located on the back clamp 30, and the center line of the pushing pressure groove 42 points to the clamping center of the back clamp 30; the two pushing arms 40 correspond to the two jaw seats 31 respectively. When the jaw seats 31 move closer to each other, they can squeeze the back side of the corresponding pushing arm 40 so that the included angle of the pushing pressure groove 42 is reduced.

[0031] The clamp assembly for holding drill pipe provided in this embodiment, by setting a mounting bracket 10, allows the entire assembly to be connected to the moving mechanism while providing a mounting base for the main clamp 20 and the back clamp 30. The main clamp 20 and the back clamp 30 respectively clamp the two sections of the drill pipe for attaching and unattaching, and are further rotatably connected to the mounting bracket 10 to perform attaching and unattaching operations. Based on this, a centering mechanism is provided in the back clamp 30, including a pair of pushing arms 40. The root hinges of the two pushing arms 40 form a V-shaped pushing pressure groove 42, restricting the centerline of the pushing pressure groove 42 to point towards the clamping center of the back clamp 30. When the drill pipe deviates from the clamping center of the back clamp 30 during clamping, the centering mechanism symmetrically adjusts the centering groove 42 towards the back clamp 30. The inner compression of the two push arms 40 reduces the angle of the V-shaped push-center pressure groove 42 between them, allowing the drill rod to move towards the clamping center of the back clamp 30 by the inner side of the push arms 40. Based on this, the back clamp 30 is configured to clamp by pushing a pair of jaw seats 31 closer together using the clamping cylinder 33. Furthermore, the pair of push arms 40 are aligned with the pair of jaw seats 31, so that when the jaw seats 31 approach each other, they can compress the back side of the corresponding push arms 40. This automatically reduces the included angle of the push-center pressure groove 42 during the process of the jaws 31 approaching each other, pushing the drill rod to the clamping center of the back clamp 30 before clamping, thus solving the problem of the drill rod deviating from the clamping center of the back clamp 30.

[0032] It should be noted that the clamping method of the main clamp 20 can be implemented using any of the existing technologies, but it is preferred to use the same clamping method as the back clamp 30, that is, the clamping cylinder 33 pushes the jaw seat 31.

[0033] It should be noted that the rotational connection between the main clamp 20 and the back clamp 30 and the mounting bracket 10 can be implemented using any existing technology, such as a slide rail, a turntable or other rotating mechanism, and a corresponding power mechanism, such as a motor, is required to drive the main clamp 20 or the back clamp 30 to rotate. This is not the main inventive point of this application, so it will not be described in detail here.

[0034] In order for the drill rod near the clamping center of the back clamp 30 to slide into the clamping center automatically, the jaw seat 31 is recessed inward on the side facing the clamping center, and jaws 34 are installed in the middle of the jaw seat 31. The jaws 34 are arranged parallel to the axis of the clamped drill rod.

[0035] To automatically limit the position of the drill rod after it has been pushed in, the jaw seat 31 is provided with two rows of positioning pins 32 to form a positioning space between the two rows of positioning pins 32. The straight line of each row of positioning pins 32 is parallel to the axis of the drill rod being clamped. The positioning pins 32 are slidably connected to the jaw seat 31 along the axial direction by springs 311. When the springs 311 are in their natural state, the outer ends of the positioning pins 32 protrude out of the jaws 34.

[0036] With the above settings, when the centering mechanism presses the drill rod toward the clamping center of the back clamp 30, since the distance from the outer end of the positioning pin 32 to the jaw 34 is less than the distance from the inner side of the push arm 40 to the corresponding jaw 34, the drill rod will smoothly pass over the row of positioning pins 32 closest to the centering mechanism and fall into the positioning space. At this time, the two rows of positioning pins 32 will partially clamp and limit the drill rod, thereby preventing the drill rod from shifting again.

[0037] It should be noted that when the drill rod has a large diameter, the positioning pin 32 may be squeezed during clamping. In this case, the positioning pin 32 can squeeze the spring to partially retract inward to compensate for the large diameter of the drill rod.

[0038] In order to allow the drill rod to pass the positioning pin 32 smoothly during the centering process, the back arc surface of the centering arm 40 of the centering mechanism abuts against one side of the jaw seat 31, and the jaw seat 31 pushes the centering arm 40 to move.

[0039] To enhance the friction when clamping the drill pipe, the clamping jaws 34 are provided with arc-shaped clamping teeth 341, the apex of which is located within an arc surface. This can effectively increase the number of contacts with the circular drill pipe, thereby increasing the friction with the drill pipe.

[0040] Preferably, the jaw seat 31 has a jaw 34 protruding from the middle, and the jaw 34 has jaw teeth 341 arranged in an arc. The apex of each jaw tooth 341 is located in an arc surface, which can increase the number of jaw teeth in contact with the drill rod.

[0041] In order to limit the outward expansion angle of the centering arm 40 and provide an installation base for the centering mechanism, the centering mechanism also includes a limiting frame 43. The roots of the two centering arms 40 are located inside the limiting frame 43, and the hinge shaft is rotatably connected to the limiting frame 43. When the reset torsion spring 41 is in its natural state, the back side of the root of the centering arm 40 abuts and presses against the inner frame of the limiting frame 43.

[0042] With the above settings, the centering mechanism and the back clamp 30 can be fixedly connected by the limiting frame 43. Furthermore, the inner wall of the limiting frame 43 can be used to limit the centering arm 40, thereby limiting the maximum value of its outward expansion angle and preventing the angle of the centering arm 40 from being unsuitable for squeezing and engaging with the clamp jaw seat 31.

[0043] Preferably, in order to further optimize the smoothness of the centering mechanism, the inner side of the centering arm 40 is set as an arc surface, and the generatrix of the inner side of the centering arm 40 is set parallel to the axis of the clamped drill rod.

[0044] To address drill pipe tilting, the mounting frame 10 includes a fixed frame 12 and an adjusting frame 13. The adjusting frame 13 is hinged to the fixed frame 12, and the straight line of the hinge axis is parallel to the moving direction of the jaws 31. A buffer cylinder 131 is hinged between the fixed frame 12 and the adjusting frame 13. The buffer cylinder 131 can buffer the relative rotational impact and vibration of the adjusting frame 13 with the hinge axis and the fixed frame 12.

[0045] With the above settings, when the drill rod is tilted, since the fixed frame 12 is fixed to the moving mechanism, when the jaw seat 31 extends and clamps, it pushes the push arm 40 to rotate inward. The push arm 40 interacts with the drill rod, and then through the back clamp 30, it drives the adjusting frame 13 to rotate to a certain extent relative to the fixed frame 12, so that the back clamp 30 is aligned with the drill rod, thereby effectively dealing with the tilting of the drill rod.

[0046] To further improve the structural performance of the above mechanism, the fixed frame 12 is hinged with a front connecting rod 14 and a rear connecting rod 15. The front connecting rod 14 and the rear connecting rod 15 are respectively hinged to the adjusting frame 13 to form a quadrilateral hinge structure. The length of the front connecting rod 14 is equal to the length of the rear connecting rod. The line where the buffer cylinder 131 is located is parallel to the horizontal direction or at an acute angle.

[0047] The fixed frame 12 and the adjusting frame 13 are connected by a 4-bar hinge, which allows the adjusting frame 13 to perform a certain degree of translation during rotation. The buffer cylinder 131 is easier to apply force and can rotate with a smaller amplitude to cope with more complex situations. The length of the front connecting rod 14 is set to be equal to the length of the rear connecting rod to achieve translation in order to deal with the situation of drill pipe deviation.

[0048] Please Figures 1 to 6 Based on reference Figure 7 This embodiment also provides a metal drill bit assembly, including: any of the above-mentioned clamping body assemblies for clamping drill rods; a second assembly including a telescopic mechanism 50, one end of which is connected to the clamping body assembly for clamping drill rods; a third assembly including a lifting mechanism 60, which is connected to the end of the telescopic mechanism 50 away from the clamping body assembly for clamping drill rods; and a fourth assembly including a rotating mechanism 70, which is connected to the lifting mechanism 60 so that the lifting mechanism 60 can rotate horizontally.

[0049] It should be noted that the telescopic mechanism 50, the lifting mechanism 60 and the rotary mechanism 70 can all adopt any related structure in the prior art. The telescopic mechanism 50 is used for translation, the lifting mechanism 60 is used for lifting, and the rotary mechanism 70 is used for horizontal rotation.

[0050] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A clamp assembly for holding drill pipes, characterized in that, include: Mounting bracket (10), the mounting bracket (10) having a mounting slot (11); The main clamp (20) and the back clamp (30) are both embedded in the mounting groove (11). The main clamp (20) is located directly above the back clamp (30). The clamping center of the main clamp (20) and the clamping center of the back clamp (30) are aligned. The main clamp (20) and the back clamp (30) are used to clamp the upper and lower sections of the drill rod, respectively. The back clamp (30) is fixedly connected to the mounting bracket (10), and the main clamp (20) is rotatably connected to the mounting bracket, with the rotating shaft collinear with the line connecting the two clamping centers; The back clamp (30) is symmetrically provided with a pair of clamp teeth (31) through the clamping cylinder (33) so that the two clamp teeth (31) can move closer or further away from each other synchronously; The centering mechanism includes a pair of centering arms (40), the roots of the two centering arms (40) are hinged and provided with a return torsion spring (41) so that a V-shaped centering groove (42) is formed between the two centering arms (40). The centering mechanism is located on the back clamp (30), and the center line of the centering groove (42) points to the clamping center of the back clamp (30). The two push arms (40) correspond to the two jaw seats (31) respectively. When the jaw seats (31) are close to each other, they can squeeze the back side of the corresponding push arms (40) so that the included angle of the push pressure groove (42) is reduced. The mounting bracket (10) includes a fixed bracket (12) and an adjusting bracket (13). The adjusting bracket (13) is hinged to the fixed bracket (12), and the straight line of the hinge axis is parallel to the moving direction of the jaw seat (31). A buffer cylinder (131) is hinged between the fixed frame (12) and the adjusting frame (13). The buffer cylinder (131) can buffer the impact and vibration when the adjusting frame (13) rotates with the fixed frame (12) around the hinge axis.

2. The clamp assembly for holding drill pipe according to claim 1, characterized in that, The jaw seat (31) is recessed inward on the side facing the clamping center, and jaws (34) are installed in the middle of the jaw seat (31). The jaws (34) are arranged parallel to the axis of the clamped drill rod.

3. The clamp assembly for holding drill pipe according to claim 2, characterized in that, The jaw holder (31) is provided with two rows of positioning pins (32) to form a positioning space between the two rows of positioning pins (32). The straight line of each row of positioning pins (32) is parallel to the axis of the clamped drill rod. The positioning pin (32) is slidably connected to the jaw seat (31) along the axial direction by a spring (311). When the spring (311) is in its natural state, the outer end of the positioning pin (32) protrudes out of the jaw (34).

4. The clamp assembly for holding drill pipe according to claim 3, characterized in that, The back arc surface of the centering arm (40) of the centering mechanism abuts against one side of the jaw seat (31), and the jaw seat (31) pushes the centering arm (40) to move.

5. The clamp assembly for holding drill pipe according to claim 2, characterized in that, The jaw holder (31) has a jaw protruding in the middle, and the jaw (34) has jaw teeth (341) arranged in an arc. The apex of each jaw tooth (341) is located in an arc surface, which can increase the number of jaw teeth in contact with the drill rod.

6. The clamp assembly for holding drill pipe according to claim 1, characterized in that, The centering mechanism also includes a limiting frame (43), the roots of the two pushing arms (40) are located inside the limiting frame (43), and the hinge shaft is rotatably connected to the limiting frame (43). When the reset torsion spring (41) is in its natural state, the back side of the root of the pushing arm (40) abuts against and presses against the inner frame of the limiting frame (43).

7. The clamp assembly for holding drill pipe according to claim 1, characterized in that, The inner side of the push arm (40) is set as an arc surface, and the generatrix of the inner side of the push arm (40) is set parallel to the axis of the clamped drill rod.

8. The clamp assembly for holding drill pipe according to claim 1, characterized in that, The fixed frame (12) has a front connecting rod (14) and a rear connecting rod (15) hinged to the adjusting frame (13) to form a quadrilateral hinge structure. The length of the front link (14) is equal to the length of the rear link; The buffer cylinder (131) is located on a straight line that is parallel to or at an acute angle to the horizontal direction.

9. A type of iron drill, characterized in that, include: The clamp assembly for holding drill pipe as described in any one of claims 1-7; Telescopic mechanism (50), one end of which is connected to the clamp body assembly for holding the drill rod; A lifting mechanism (60) is connected to one end of the telescopic mechanism (50) away from the clamp assembly for holding the drill rod; A slewing mechanism (70) is connected to the lifting mechanism (60) so that the lifting mechanism (60) can rotate horizontally.

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