Single-oil-cylinder drill rod clamping structure

Abstract

The invention discloses a single-oil-cylinder drill rod clamping structure, and belongs to the technical field of drill rod clamping. The device comprises a connecting flange connected with a gearbox, a clamping cylinder is fixedly arranged at the other end of the connecting flange, a plurality of sets of inner holes are formed in the side face of the clamping cylinder in a surrounding mode, a slip is arranged in each set of inner holes in a sliding mode, the device further comprises an outer mounting cylinder, an inner mounting cylinder is rotationally arranged in the outer mounting cylinder, and the outer mounting cylinder is fixedly connected with the inner mounting cylinder. A fixing frame is arranged at the top of the mounting inner cylinder in a matched mode, a plurality of sets of trapezoidal sliding blocks corresponding to the slips in position are fixedly arranged on the fixing frame in a surrounding mode, and slopes matched with each other are arranged on the sides, close to the trapezoidal sliding blocks, of the slips and the sides, close to the slips, of the trapezoidal sliding blocks; and an acute angle is formed between the slope surface and the upward extending axis of the clamping cylinder. The clamping structure is simple in internal layout, the hydraulic pushing structure directly drives the mounting outer cylinder and other components to move through the outer connecting cylinder, complex and roundabout line design is avoided, and the comprehensive maintenance cost is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of drill pipe clamping, and particularly to a single-cylinder drill pipe clamping structure. Background Technology

[0002] Drill pipe clamping technology is a key operation in drilling operations. It refers to the use of special clamps to firmly fix the drill pipe to the rotary device of the drilling rig, ensuring that the drill pipe and drill bit rotate synchronously during drilling and that there is no axial or radial displacement.

[0003] Hydraulic mechanical slips are commonly used clamps in drill pipe clamping. These clamps are mounted on the drill rig's power head or rotary table and contain radially movable slips. During operation, the hydraulic system drives a piston to push the slips towards the center, tightly gripping the outer wall of the drill pipe through friction. After clamping, the clamp rotates synchronously with the drill pipe, simultaneously bearing the counter-torque and axial thrust during drilling.

[0004] While hydraulic mechanical slips achieve a compact design by integrating hydraulic components with mechanical slips, their internal piping layout is highly dense, and the connections between hydraulic valve blocks, cylinders, and slip assemblies are complex. The tangled or concealed design of the oil pipes makes leak detection difficult, and space constraints can easily cause secondary damage when replacing seals or hydraulic components. This necessitates the disassembly of numerous related components to locate the fault during subsequent maintenance, extending downtime and significantly increasing overall maintenance costs. Summary of the Invention

[0005] This invention provides a single-cylinder drill rod clamping structure, which can solve the problems of highly dense internal pipeline layout, complex connection between hydraulic valve block, cylinder and clamping slip assembly, and difficulty in maintenance in the existing hydraulic mechanical slip technology.

[0006] A single-cylinder drill rod clamping structure includes a connecting flange connected to a gearbox, a clamping cylinder fixedly mounted at the other end of the connecting flange, a plurality of sets of inner holes circumferentially formed on the side of the clamping cylinder, and a slip slidably mounted inside each set of inner holes. The device also includes an outer mounting cylinder, an inner mounting cylinder rotatably mounted inside the outer mounting cylinder, a fixing frame fitted on the top of the inner mounting cylinder, and a plurality of trapezoidal sliders corresponding to the positions of the slips fixedly mounted on the fixing frame. The slips near the trapezoidal sliders and the trapezoidal sliders near the slips are provided with mutually cooperating slopes, the slopes forming an acute angle with the upwardly extending axis of the clamping cylinder. A hydraulic pushing structure for pushing the outer mounting cylinder upward is fitted on the outside of the outer mounting cylinder.

[0007] As a further aspect of the present invention: the hydraulic pushing structure includes an outer connecting cylinder that is fitted to the outside of the mounting outer cylinder. A hydraulic telescopic rod is provided on the side of the outer connecting cylinder. The fixed end of the hydraulic telescopic rod is connected to the gearbox, and the telescopic end is connected to the outer connecting cylinder. Through the telescopic operation of the hydraulic telescopic rod, the outer connecting cylinder and the mounting outer cylinder are driven to move up and down.

[0008] As a further embodiment of the present invention: the two sides of the mounting outer cylinder are rotatably arranged with the two sides inside the outer connecting cylinder, the hydraulic telescopic rod is movably arranged between the gearbox and the outer connecting cylinder, a support rod is movably arranged on the side of the outer connecting cylinder away from the outer hydraulic telescopic rod, a guide sleeve is slidably fitted on the support rod, and the other end of the guide sleeve is movably connected to the gearbox.

[0009] As a further aspect of the present invention: multiple sets of guide sliders are longitudinally distributed on the outer side of the clamping cylinder, and multiple sets of guide grooves are opened on the inner side of the mounting inner cylinder to slide and cooperate with the corresponding guide sliders.

[0010] As a further aspect of the present invention, a roller for reducing the friction of the slip is rotatably provided above the inner hole.

[0011] As a further aspect of the present invention, an upper bearing is provided between the upper end of the inner mounting cylinder and the outer mounting cylinder.

[0012] As a further aspect of the present invention, a lower bearing is provided between the lower end of the inner mounting cylinder and the outer mounting cylinder.

[0013] As a further aspect of the present invention: the surface of the slip near the axis of the clamping cylinder is provided with protruding teeth.

[0014] As a further embodiment of the present invention: an upper cover plate is fixedly provided on the top of the inner cylinder, the upper cover plate is fixedly connected to the fixing frame, and an upper washer is provided between the bottom of the upper cover plate and the inner cylinder.

[0015] As a further embodiment of the present invention: a fixing ring for positioning the lower bearing is fixedly provided at the bottom of the inner cylinder, a lower washer is fixedly provided on the outside of the fixing ring, a lower cover plate is fixedly provided at the bottom of the outer cylinder, and an insertion port concentrically provided in the middle of the lower cover plate is provided.

[0016] The beneficial effects of this invention are:

[0017] 1. The clamping structure provided by this invention features a simple internal layout. The hydraulic pushing structure directly drives the movement of components such as the mounting outer cylinder through the outer connecting cylinder. The pipeline connections are clear and straightforward, avoiding complex and circuitous wiring designs. During maintenance, because each component is relatively independent and the connection relationship is simple, the problem can be quickly located when a fault occurs, without the need to disassemble related components layer by layer as in complex structures. Moreover, the simple layout makes operations such as replacing seals or hydraulic components more convenient, reducing operational difficulties caused by limited space and component interference, thereby greatly shortening equipment downtime and effectively reducing overall maintenance costs.

[0018] 2. In use, when the inner cylinder is stationary, the guide slider on the outside of the clamping cylinder slides into the guide groove on the inside of the inner cylinder, providing stable guidance for the structure. Simultaneously, the upper and lower bearings limit the movement of the inner cylinder, ensuring relative stability between the outer and inner cylinders. When the inner cylinder rotates, the upper cover plate and fixing frame rotate accordingly, while the slips and guide slider remain stationary. This dynamic-static combination design ensures that the slips accurately clamp the drill rod, and the guide slider slides smoothly within the guide groove of the fixing frame, maintaining coordination throughout the clamping and guiding process. Rollers reduce friction during slip movement, and convex teeth improve the clamping effect. These multiple design features collectively ensure that the drill rod is stably clamped regardless of the state of the inner cylinder. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a single-cylinder drill rod clamping structure provided by the present invention;

[0020] Figure 2 A schematic diagram of the overall cross-sectional structure of a single-cylinder drill rod clamping structure provided by the present invention;

[0021] Figure 3 This is a schematic diagram of the assembly structure of the clamping cylinder of the single-cylinder drill rod clamping structure provided by the present invention;

[0022] Figure 4 This invention provides a schematic diagram of the structure of a single-cylinder drill rod clamping structure during the assembly of the outer cylinder;

[0023] Figure 5 This invention provides a schematic diagram of the left and right cross-sectional structure of the outer cylinder of a single-cylinder drill rod clamping structure.

[0024] Figure 6 This is a schematic diagram of the front and rear cross-sectional structure of a single-cylinder drill rod clamping structure provided by the present invention.

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

[0026] 1. Connecting flange; 2. Clamping cylinder; 201. Inner hole; 202. Slip; 203. Roller; 204. Guide slider; 3. Installing outer cylinder; 301. Fixing bracket; 302. Trapezoidal slider; 303. Upper cover plate; 304. Upper washer; 305. Upper bearing; 306. Lower cover plate; 307. Insert; 308. Fixing ring; 309. Lower washer; 310. Lower bearing; 311. Guide groove; 312. Installing inner cylinder; 4. Hydraulic pushing structure; 401. Outer connecting cylinder; 402. Hydraulic telescopic rod; 403. Support rod; 404. Guide sleeve. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0028] like Figures 1 to 6 As shown in the figure, an embodiment of the present invention provides a single-cylinder drill rod clamping structure, including a connecting flange 1 connected to a gearbox, and a clamping cylinder 2 fixedly mounted on the other end of the connecting flange 1. Multiple sets of inner holes 201 are formed around the side of the clamping cylinder 2, and a slip 202 is slidably mounted inside each set of inner holes 201. The device is also equipped with an outer mounting cylinder 3, inside which an inner mounting cylinder 312 is rotatably mounted. A fixing frame 301 is fitted on the top of the inner mounting cylinder 312, and multiple sets of trapezoidal sliders 302 corresponding to the positions of the slips 202 are fixedly mounted around the fixing frame 301. Both the slips 202 near the trapezoidal sliders 302 and the trapezoidal sliders 302 near the slips 202 have mutually cooperating slopes, and the slopes form an acute angle with the upward-extending axis of the clamping cylinder 2. A hydraulic pushing structure 4 for pushing the outer mounting cylinder 3 upward is fitted on the outside of the outer mounting cylinder 3. In actual operation, the hydraulic push structure 4 drives the outer cylinder 3 to move upward, which in turn causes the slope of the trapezoidal slider 302 to press against the slope of the slip 202, while pushing multiple sets of slips 202 to move inward, ultimately fixing the drill rod.

[0029] In one specific embodiment, the hydraulic pushing structure 4 includes an outer connecting cylinder 401 fixedly disposed on the outside of the mounting outer cylinder 3, and a hydraulic telescopic rod 402 fixed to the side of the outer connecting cylinder 401. The fixed end of the hydraulic telescopic rod 402 is connected to the gearbox, and the telescopic end is connected to the outer connecting cylinder 401. In actual operation, the telescopic operation of the hydraulic telescopic rod 402 can directly drive the outer connecting cylinder 401 and the mounting outer cylinder 3 to move up and down, thereby completing the pushing operation of the slip 202.

[0030] In the second specific embodiment, compared with the above embodiment, in this embodiment, the outer cylinder 3 is rotatably mounted on both sides and the inner sides of the outer connecting cylinder 401, and the hydraulic telescopic rod 402 is movably mounted between the gearbox and the outer connecting cylinder 401. A support rod 403 is movably mounted on the side of the outer connecting cylinder 401 away from the hydraulic telescopic rod 402, and a guide sleeve 404 is slidably fitted on the support rod 403. The other end of the guide sleeve 404 is movably connected to the gearbox. When clamping the drill rod, the hydraulic telescopic rod 402 retracts, thereby causing one side of the outer connecting cylinder 401 to move upward. Since the outer connecting cylinder 401 is rotatably connected to the outer cylinder 3, the outer connecting cylinder 401 tilts as it moves upward, and the support rod 403 inserts upward into the guide sleeve 404, simultaneously acting as a fulcrum to ensure the stability of the outer connecting cylinder 401. The upward movement of the outer connecting cylinder 401 causes the outer cylinder 3 and the inner cylinder 312 and their connecting components to move upward, thereby causing the trapezoidal slider 302 to move upward, ultimately pushing the slip 202.

[0031] Furthermore, to ensure structural stability, multiple sets of guide sliders 204 are longitudinally distributed on the outer side of the clamping cylinder 2, and multiple sets of guide grooves 311 are formed on the inner side of the mounting inner cylinder 312, which slide in cooperation with the corresponding guide sliders 204. When the mounting inner cylinder 312 moves relative to the clamping cylinder 2, the guide sliders 204 move along the guide grooves 311, thereby maintaining a stable sliding effect. Simultaneously, an upper bearing 305 is fitted between the upper end of the mounting inner cylinder 312 and the mounting outer cylinder 3, and a lower bearing 310 is fitted between the lower end of the mounting inner cylinder 312 and the mounting outer cylinder 3. Figure 2 As shown, the upper bearing 305 and the lower bearing 310 can limit the installation of the inner cylinder 312, and maintain the relative stability of the outer cylinder 3 and the inner cylinder 312 when the inner cylinder 312 rotates.

[0032] Furthermore, to facilitate the installation of the mating components, an annular protrusion is provided in the middle of each side of the outer cylinder 3, and an annular protrusion is provided on the upper side of the inner cylinder 312. See reference for details. Figure 2 , Figure 5 and Figure 6An upper cover plate 303 is fixedly installed on the top of the inner cylinder 312, and the upper cover plate 303 is fixedly connected to the fixing frame 301. An upper washer 304 is fitted between the bottom of the upper cover plate 303 and the inner cylinder 312 to ensure the stability of the upper cover plate 303. A fixing ring 308 for positioning the lower bearing 310 is fixedly installed at the bottom of the inner cylinder 312, and a lower washer 309 is fixedly installed on the outside of the fixing ring 308. A lower cover plate 306 is fixedly installed at the bottom of the outer cylinder 3, and an insertion port 307 concentrically arranged with the clamping cylinder 2 is opened in the middle of the lower cover plate 306. When the inner cylinder 312 rotates, it will drive the upper cover plate 303 and the fixing frame 301 to rotate, while the clamping slip 202 and the guide slider 204 remain stationary. This ensures that the clamping slip 202 can accurately clamp the drill rod during use, while the guide slider 204 slides smoothly in the guide groove of the fixing frame 301, ensuring the coordination of the entire clamping and guiding process.

[0033] In addition, to reduce friction during the movement of the slip 202, a roller 203 is rotatably mounted above the inner hole 201 to reduce friction, allowing the slip 202 to move stably inward under the action of the trapezoidal slider 302. The surface of the slip 202 near the axis of the clamping cylinder 2 has protruding teeth to improve the clamping effect. To prevent the slip 202 from falling directly into the clamping cylinder 2, a limiting component that mates with the inner hole 201 can be provided on the outer side of the slip 202. In actual operation, the position of the trapezoidal slider 302 can be adjusted to ensure sufficient clearance between the roller 203 and the trapezoidal slider 302. This not only facilitates the operator in adjusting the position of the slip 202 and feeding in the drill pipe, but also allows for easy removal and replacement of the slip 202 when needed.

[0034] Working principle: Before the equipment is ready to perform drill pipe clamping operation, the outer connecting cylinder 401, the outer mounting cylinder 3, the inner mounting cylinder 312 and their related connecting parts are all in a relatively low position, the trapezoidal slider 302 is also in the initial position, and the slip 202 is in a ready-to-work state under the constraint of its own position and the inner hole 201.

[0035] When the drill pipe clamping operation begins, the hydraulic system activates, controlling the hydraulic telescopic rod 402 to retract. As the hydraulic telescopic rod 402 retracts, the resulting tension acts on the outer connecting cylinder 401. Under this tension, one side of the outer connecting cylinder 401 begins to move upward. Since the outer connecting cylinder 401 and the mounting outer cylinder 3 are rotatably connected, the entire outer connecting cylinder 401 will tilt as it moves upward. As the outer connecting cylinder 401 tilts and moves upward, the support rod 403 inserts upward into the guide sleeve 404, which it slides into. After the support rod 403 is inserted into the guide sleeve 404, a stable fulcrum structure is formed, ensuring the stability of the outer connecting cylinder 401 during its continued upward movement and preventing swaying or displacement.

[0036] Under the continuous tension of the hydraulic telescopic rod 402 and the stable support formed by the support rod 403 and the guide sleeve 404, the outer connecting cylinder 401 moves upward continuously. The upward movement of the outer connecting cylinder 401 causes the related mounting outer cylinder 3 to move upward, which in turn causes the internally rotating mounting inner cylinder 312 and its connecting components to move upward together. During the upward movement of the mounting inner cylinder 312, the fixing frame 301 fixed at its top also moves upward, thereby causing the multiple sets of trapezoidal sliders 302 arranged around the fixing frame 301 to move upward. As the trapezoidal sliders 302 move upward, their slopes begin to contact and exert a squeezing effect on the mating slopes of the slip 202. Under the squeezing effect of the slopes of the trapezoidal sliders 302, the slip 202 is subjected to a radially inward force along the clamping cylinder 2. Under the action of this force, the multiple sets of slips 202 move inward simultaneously. As the slip 202 moves inward, the protruding teeth on the surface of the slip 202 near the axis of the clamping cylinder 2 gradually approach the drill pipe. When the slip 202 moves to the appropriate position, the protruding teeth make tight contact with the drill pipe surface, generating sufficient clamping force to fix the drill pipe. At this time, the drill pipe is stably clamped between the slips 202, and the gearbox drives the connecting flange 1, clamping cylinder 2, mounting inner cylinder 312 and their mating components to rotate, realizing drilling and other operations.

[0037] When drilling operations are completed and the drill pipe needs to be released, the hydraulic system controls the extension of the hydraulic telescopic rod 402. The thrust generated by the extension of the hydraulic telescopic rod 402 causes the outer connecting cylinder 401 to move downwards, which in turn drives the outer mounting cylinder 3, the inner mounting cylinder 312, and their connecting components to move downwards. The trapezoidal slider 302 also moves downwards, and its squeezing effect on the slip 202 gradually decreases until it disappears. Under the action of its own elasticity or gravity, the slip 202 moves outwards back to its initial position, releasing the grip on the drill pipe. The drill pipe can then be easily removed, and the entire clamping structure returns to its initial ready-to-work state, awaiting the next drill pipe clamping operation.

[0038] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A single-oil-cylinder drill rod clamping structure, comprising a connecting flange (1) connected with a gear box, one end of the connecting flange (1) being fixedly provided with a clamping cylinder (2), a plurality of groups of inner holes (201) being formed around the side of the clamping cylinder (2), and a slip (202) being slidably arranged in each group of the inner holes (201), characterized in that, The device also includes a mounting outer cylinder (3), which is internally rotatably provided with a mounting inner cylinder (312), and the top of the mounting inner cylinder (312) is matched with a fixing frame (301), and a plurality of trapezoidal sliding blocks (302) corresponding to the positions of the slips (202) are fixedly arranged on the fixing frame (301) in a surrounding manner, and the side of the slip (202) close to the trapezoidal sliding block (302) and the side of the trapezoidal sliding block (302) close to the slip (202) are both provided with mutually matched inclined surfaces, and the inclined surfaces are arranged at an acute angle with the upwardly extending axis of the clamping cylinder (2), and the outside of the mounting outer cylinder (3) is matched with a hydraulic pushing structure (4) for pushing the mounting outer cylinder (3) to move upward.

2. A single cylinder pipe clamp structure as claimed in claim 1, wherein, The hydraulic pushing structure (4) includes an outer connecting cylinder (401) matched and arranged on the outside of the mounting outer cylinder (3), and the side of the outer connecting cylinder (401) is provided with a hydraulic telescopic rod (402), and the fixed end of the hydraulic telescopic rod (402) is matched and connected with a gear box, and the telescopic end is matched and connected with the outer connecting cylinder (401), and through the telescopic operation of the hydraulic telescopic rod (402), the outer connecting cylinder (401) and the mounting outer cylinder (3) are driven to move up and down.

3. A single cylinder pipe clamp structure as claimed in claim 2, wherein The two sides of the mounting outer cylinder (3) are rotatably arranged with the two sides of the inside of the outer connecting cylinder (401), the hydraulic telescopic rod (402) is movably arranged between the gear box and the outer connecting cylinder (401), the side of the outer connecting cylinder (401) away from the outer hydraulic telescopic rod (402) is movably provided with a supporting rod (403), the supporting rod (403) is slidably matched with a guide sleeve (404), and the other end of the guide sleeve (404) is movably connected with the gear box.

4. A single cylinder pipe clamp structure as claimed in claim 3, wherein A plurality of guide sliding blocks (204) are longitudinally distributed on the outside of the clamping cylinder (2), and a plurality of guide sliding grooves (311) matched and slidably with the corresponding guide sliding blocks (204) are formed in the inside of the mounting inner cylinder (312).

5. A single cylinder pipe clamp structure as claimed in claim 1 or 3 or 4, wherein, A roller (203) for reducing the friction of the slip (202) is rotatably arranged above the inner hole (201).

6. A single cylinder pipe clamp structure as claimed in claim 5, wherein, An upper bearing (305) is matched and arranged between the upper end of the mounting inner cylinder (312) and the mounting outer cylinder (3).

7. A single cylinder pipe clamp structure as claimed in claim 6, wherein A lower bearing (310) is matched and arranged between the lower end of the mounting inner cylinder (312) and the mounting outer cylinder (3).

8. A single cylinder pipe clamp structure as claimed in claim 7, wherein A convex tooth is arranged on the surface of the side of the slip (202) close to the axis of the clamping cylinder (2).

9. A single cylinder pipe clamp structure as claimed in claim 8, wherein, An upper cover plate (303) is fixedly arranged on the top of the mounting inner cylinder (312), the upper cover plate (303) is fixedly connected with the fixing frame (301), and an upper gasket (304) is matched and arranged between the bottom of the upper cover plate (303) and the mounting inner cylinder (312).

10. The single-oil-cylinder pipe clamp structure according to claim 9, characterized by A fixing ring (308) for positioning the lower bearing (310) is fixedly arranged on the bottom of the mounting inner cylinder (312), a lower gasket (309) is fixedly arranged on the outside of the fixing ring (308), and a lower cover plate (306) is fixedly arranged on the bottom of the mounting outer cylinder (3), and a socket (307) concentrically arranged with the clamping cylinder (2) is formed in the middle of the lower cover plate (306).

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