An internal hole rotary wrench

Abstract

The present invention discloses an inner hole rotary wrench, which includes a rotary shaft and a plurality of claws evenly distributed circumferentially. The cross-section of the rotary shaft is circular, and a bevel nut is threadedly connected to the outer peripheral surface of the upper end portion. The bevel nut has a trapezoidal structure with a wider upper part and a narrower lower part, and simultaneously abuts against the inner peripheral surfaces of the upper end portions of the plurality of claws. The lower end portion of the rotary shaft is fixedly inserted into a coaxial power connector. A rotary positioning mechanism that abuts and cooperates with the power connector is sleeved on the outer peripheral surface of the middle part of the rotary shaft. The rotary positioning mechanism is also radially movably connected to the lower end portions of the plurality of claws. The present invention greatly increases the contact area with the inner hole wall of the protective cap, thereby improving the stability and reliability of the bite, enhancing the disassembly efficiency and disassembly effect, and at the same time avoiding the occurrence of the situation where the rotary shaft and the claws axially offset from each other, thereby further enhancing the disassembly efficiency and disassembly effect.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling and workover operations. Specifically, it relates to an internal hole rotary wrench. Background Art

[0002] In oil drilling and workover operations, casing is essential. The connection between casings generally uses threaded connections. When the casing leaves the factory, protective caps need to be installed on the internal and external threads respectively to protect these connection threads. Before running the casing at the drilling site, it is often necessary to remove the protective caps to clean the thread storage grease applied on the internal and external threads. The traditional disassembly tool is a pipe wrench, that is, the protective cap is rotated at a small angle by the pipe wrench. This disassembly method not only takes a long time and has a high labor intensity, but also is extremely easy to damage the protective cap.

[0003] At present, there is an internal expansion type internal hole wrench for rotating accessories with radial internal holes such as protective caps. Although it can symmetrically expand and bite the inner hole wall of the protective cap from the inner wall to make it rotate together to achieve the disassembly operation, thereby reducing the damage to the protective cap to a certain extent and improving the operation convenience, the contact area with the inner hole wall of the protective cap is still limited, resulting in general stability and reliability of the bite, and further resulting in general disassembly efficiency and disassembly effect. At the same time, it is extremely easy for the rotation axis and the claw to axially offset from each other, and position adjustment is required, further affecting the disassembly efficiency and disassembly effect. For example, Chinese Patent Grant Publication No. CN206610009U, publication date November 3, 2017, discloses an internal expansion type internal hole wrench. It is proposed in the article that "it consists of a chuck sleeve, a mandrel, and a handle. The chuck sleeve is sleeved on the outer diameter of the mandrel. The front end of the chuck sleeve is an oval internal hole, and axial teeth are processed on the outer diameter, and the front end of the chuck sleeve is cut into four petals; the front end of the mandrel is an oval symmetric cam structure, which is in clearance fit with the oval internal hole at the front end of the chuck sleeve; the handle is vertically installed at the tail end of the mandrel".

[0004] The chuck sleeve with axial teeth in this prior art can symmetrically expand and bite the inner hole wall of the protective cap (or other accessories with radial internal holes) from the inner wall to make it rotate together to achieve the disassembly operation, thereby increasing the contact area with the inner hole wall of the protective cap to a certain extent, reducing the damage to the protective cap, and improving the operation convenience. However, the front end of the mandrel (equivalent to the rotation axis) in this prior art is an oval symmetric cam structure, and the front end of the chuck sleeve (equivalent to the claw) has an oval internal hole, which is an unequal diameter fit. During disassembly, only symmetric expansion can be performed, and the contact area between the front end of the chuck sleeve and the inner hole wall of the protective cap is still limited, resulting in general stability and reliability of the bite, and further resulting in general disassembly efficiency and disassembly effect. At the same time, in this prior art, the chuck sleeve is only manually grasped, and it is extremely easy for the front end of the chuck sleeve and the front end of the mandrel to axially offset from each other, and position adjustment is required, further affecting the disassembly efficiency and disassembly effect.

[0005] For this reason, a new technical solution is needed to solve the above technical problems. Summary of the Invention

[0006] The purpose of the present invention is to provide an inner hole rotary wrench to solve the technical problems in the current inner expansion type inner hole wrench in the background technology. The contact area between the claw and the inner hole wall of the protective cap is still limited, resulting in general stability and reliability of the bite, and further making the disassembly efficiency and disassembly effect average. At the same time, axial offset is extremely likely to occur between the rotary shaft and the claw, and position adjustment is required, thus further affecting the disassembly efficiency and disassembly effect.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] An inner hole rotary wrench includes a rotary shaft. The cross-section of the rotary shaft is circular, and a circular retaining ring is coaxially arranged on the upper end surface. A bolt is connected between the center position of the circular retaining ring and the rotary shaft. The outer peripheral surface of the upper end portion of the rotary shaft is threadedly connected with an inclined surface nut. The inclined surface nut has a trapezoidal structure with a wider upper part and a narrower lower part, and simultaneously abuts against the inner peripheral surfaces of the upper end portions of four claws. The claws are evenly distributed in the circumferential direction. The lower end portion of the rotary shaft is fixedly inserted into a coaxial power joint. A rotary positioning mechanism that abuts against the power joint is sleeved on the outer peripheral surface of the middle part of the rotary shaft. The rotary positioning mechanism is also radially movably connected to the lower end portions of the four claws;

[0009] Further, the upper end portion of the power joint has a jack adapted to the lower end portion of the rotary shaft. The lower end portion of the power joint has a rectangular jack for connecting with an external power source. The rectangular jack is integrally and coaxially communicated with the jack. The lower end portion of the rotary shaft is inserted into the jack, and a B-type pin II is radially penetrated. The B-type pin II penetrates through the upper end portion of the power joint and is locked with an open pin II;

[0010] Further, the rotation positioning mechanism includes a cover plate, a first pressing ring, a second pressing ring, and an axial limiting buckle. The cover plate is annular, and a stepped hole formed by inward concavity is provided on the inner peripheral surface of the upper end portion. A bearing is embedded in the stepped hole, and the bearing is simultaneously sleeved on the outer peripheral surface of the middle portion of the rotating shaft. The first pressing ring is clamped at the top of the stepped hole, and a plurality of bolt and nut assemblies are connected between the first pressing ring and the upper end portion of the cover plate. The first pressing ring and the second pressing ring respectively abut and cooperate with the upper end surface and the lower end surface of the bearing. The second pressing ring and the axial limiting buckle are both sleeved on the outer peripheral surface of the rotating shaft. The upper end surface of the axial limiting buckle abuts and cooperates with the lower end surface of the second pressing ring, and the lower end surface of the axial limiting buckle abuts and cooperates with the upper end surface of the power joint. Axial grooves for accommodating the lower end portions of the claws are respectively formed by inward concavity on the outer peripheral surface of the upper end portion of the cover plate. B-type pin shafts I are horizontally penetrated through the lower end portions of the claws respectively. The B-type pin shafts I all penetrate through the upper end portion of the cover plate and are respectively locked with split pins I. The B-type pin shafts I are all perpendicular to the radial direction, and horizontal sliding holes for the B-type pin shafts I to pass through and move radially are respectively formed in the upper end portion of the cover plate.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] 1. In the present invention, the cross-section of the rotating shaft is circular, and a bevel nut with a trapezoidal structure that is wider at the top and narrower at the bottom is threadedly connected to the outer peripheral surface of the upper end portion of the rotating shaft. The bevel nut simultaneously abuts against the inner peripheral surfaces of the upper end portions of a plurality of claws. Through this cooperative setting, the rotating shaft, the bevel nut, and the claws act together. The rotation of the rotating shaft drives the bevel nut to axially move downward in the inner expansion space formed by the enclosure of a plurality of claws. The axial downward movement of the bevel nut causes all the claws that abut and cooperate with the bevel nut to synchronously move radially outward until they firmly bite the inner hole wall of the friction cap and drive it to rotate together, thereby realizing the disassembly of the cap. In the present invention, by utilizing the structural characteristics and connection characteristics of the rotating shaft and the bevel nut, a circumferential tightening structure is formed, greatly increasing the contact area between the claws and the inner hole wall of the cap, thereby improving the stability and reliability of the bite, and further enhancing the disassembly efficiency and disassembly effect. On this basis, by utilizing the cooperative setting of the rotation positioning mechanism, while the rotating shaft can rotate and the claws can move radially, the axial movement of the rotating shaft and the claws is simultaneously limited, avoiding the occurrence of the situation where the rotating shaft and the claws axially deviate from each other, eliminating the need for position adjustment, ensuring the smooth completion of the disassembly operation at one time, and further enhancing the disassembly efficiency and disassembly effect. In addition, the setting of the power joint effectively guarantees the disassembly efficiency compared with manual operation;

[0013] 2. The upper end of the power connector in the present invention has a jack, the lower end of the rotating shaft is inserted into the jack, and a Type B pin II is radially inserted through the rotating shaft. The Type B pin II penetrates through the upper end of the power connector and is locked with a split pin II. Through the cooperation of the Type B pin II, the split pin II with the power connector and the rotating shaft, the stability of the connection and installation between the rotating shaft and the power connector is effectively ensured. At the same time, the rotation positioning mechanism includes a cover plate, a bearing, a pressure ring I, a pressure ring II, and an axial limit buckle. A stepped hole formed by concave inward is provided on the inner peripheral surface of the upper end of the cover plate. A bearing is embedded in the stepped hole, and the bearing is simultaneously sleeved on the outer peripheral surface of the middle part of the rotating shaft. On this basis, through the pressure ring I and the pressure ring II respectively abutting against the upper end surface and the lower end surface of the bearing, and the upper end surface of the axial limit buckle abutting against the lower end surface of the pressure ring II, and the lower end surface of the axial limit buckle abutting against the upper end surface of the power connector, while ensuring the radial stability of the rotating shaft, the axial movement of the rotating shaft together with the power connector is effectively restricted, avoiding the situation where the rotating shaft and the claw are axially offset from each other;

[0014] 3. A Type B pin I is horizontally inserted through the lower end of each claw in the present invention. The Type B pin I penetrates through the upper end of the cover plate and is respectively locked with a split pin I. Through the cooperation of the Type B pin I, the split pin I with the claw and the cover plate, the stability of the connection and installation between the claw and the cover plate while the claw can move radially is effectively improved, thereby restricting the axial movement of the claw, and further avoiding the situation where the rotating shaft and the claw are axially offset from each other;

[0015] 4. The lower end of the power connector of the present invention has a rectangular jack for connecting with an external power source such as an electric power head. Through the cooperation of the rectangular jack, the linkage cooperation of the external power source, the power connector, and the rotating shaft can be effectively ensured, that is, the external power source drives the power connector to rotate, and the rotation of the power connector drives the rotating shaft to rotate synchronously. By using the external power source, the overall disassembly efficiency is further ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the front view of the present invention;

[0017] Figure 2 is Figure 1 the sectional view of;

[0018] Figure 3 is the side view of the present invention;

[0019] In the figure: 1. Rotating shaft; 2. Chuck; 3. Tapered nut; 4. Power connector; 5. Cover plate; 6. Step hole; 7. Bearing; 8. Pressing ring I; 9. Pressing ring II; 10. Axial limit buckle; 11. Bolt-nut assembly; 12. B-type pin I; 13. Split pin I; 14. Axial slot; 15. Horizontal sliding hole; 16. Jack; 17. Rectangular jack; 18. B-type pin II; 19. Split pin II; 20. Circular retaining ring; 21. Bolt. Detailed implementation manners

[0020] The following embodiments are used to further illustrate the content of the present invention and do not limit the application of the present invention.

[0021] Please refer to Figures 1 to 3 , which shows an inner hole rotary wrench, including a rotating shaft 1 with a circular cross-section. A coaxial circular retaining ring 20 is provided on the upper end surface of the rotating shaft 1. A bolt 21 is connected between the central position of the circular retaining ring 20 and the rotating shaft 1. Four chucks 2 are evenly distributed along the circumferential direction on the outer peripheral surface of the upper end of the rotating shaft 1 (the basic structures such as the outer diameter axial teeth on the existing chucks are not specifically described here, but their function realization should not be limited thereby). The inner peripheral surfaces of the upper ends of the four chucks 2 are jointly abutted and fitted with a tapered nut 3. The tapered nut 3 is threadedly connected to the outer peripheral surface of the upper end of the rotating shaft 1 and has a trapezoidal longitudinal section that is wider at the top and narrower at the bottom;

[0022] Further, a bearing 7 is sleeved on the outer peripheral surface of the middle part of the rotating shaft 1. The bearing 7 is embedded in the inner peripheral surface of a cover plate 5. The cover plate 5 is annular and is provided with a step hole 6 that cooperates with the bearing 7. The step hole 6 is recessed in the inner peripheral surface of the upper end of the cover plate 5 and a pressing ring I 8 is clamped at the top. The lower end surface of the pressing ring I 8 abuts and cooperates with the upper end surface of the bearing 7 and is circumferentially connected to 4 bolt-nut assemblies 11 (including bolts and nuts) between the upper end of the cover plate 5. The lower end surface of the bearing 7 abuts and cooperates with a pressing ring II 9. The lower end surface of the pressing ring II 9 abuts and cooperates with an axial limit buckle 10. Both the axial limit buckle 10 and the pressing ring II 9 are sleeved on the outer peripheral surface of the rotating shaft 1. The lower end surface of the axial limit buckle 10 abuts and cooperates with a power connector 4. The power connector 4 is coaxially arranged with the rotating shaft 1. The central position of the upper end of the power connector 4 has a jack 16. The lower end of the rotating shaft 1 is inserted into the jack 16 and a B-type pin II 18 is radially penetrated (the basic structures such as the shaft shoulder and split pin hole on the existing B-type pin are not specifically described here, but their function realization should not be limited thereby). The B-type pin II 18 radially penetrates the upper end of the power connector 4 and a split pin II 19 is locked. The lower end of the power connector 4 has a rectangular jack 17 for connecting with an external power source. The rectangular jack 17 is integrally and coaxially communicated with the jack 16;

[0023] Further, four axially distributed grooves 14 are evenly formed by inward concaving the outer peripheral surface of the upper end portion of the cover plate 5 along the circumferential direction. The lower end portions of the four claws 2 are respectively horizontally penetrated with a B-type pin shaft I 12 and are respectively and correspondingly clamped in the four axially distributed grooves 14. The B-type pin shaft I 12 is respectively arranged perpendicular to the radial direction. The upper end portion of the cover plate 5 is correspondingly provided with horizontal sliding holes 15 for the B-type pin shaft I 12 to pass through and move radially. The B-type pin shaft I 12 respectively penetrates through the horizontal sliding holes 15 and is respectively locked with a split pin I 13.

[0024] During use, first insert an external power source (which can be an electric power head or a pneumatic power head. The functions and structures of conventional devices such as electric power heads or pneumatic power heads are well-known in the art, and the connection settings are also common knowledge, so no further description will be given here and they are not shown in the drawings) into the rectangular jack 17 of the power connector 4. Then insert the rotating shaft 1 together with the four claws 2 into the inner hole wall of the protective cap. Then control the external power source to work, drive the power connector 4 to drive the rotating shaft 1 to rotate. Further, under the action of the threaded connection between the rotating shaft 1 and the inclined surface nut 3, drive the inclined surface nut 3 to move axially downward. Subsequently, under the action of the trapezoidal structure with a wider upper part and a narrower lower part of the inclined surface nut 3, the four claws 2 move radially outward synchronously until the four claws 2 firmly bite and friction the inner hole wall of the protective cap to drive it to rotate together, completing the disassembly of the protective cap.

Claims

1. An internal hole rotary wrench, comprising a rotary shaft and a plurality of claws evenly distributed circumferentially, characterized in that, The cross-section of the rotating shaft is circular, and a bevel nut is threadedly connected to the outer peripheral surface of the upper end portion. The bevel nut has a trapezoidal structure with a wider upper part and a narrower lower part, and simultaneously abuts against the inner peripheral surfaces of the upper end portions of a plurality of claw members. The lower end portion of the rotating shaft is fixedly inserted into a coaxial power connector. A rotary positioning mechanism that abuts against the power connector is sleeved on the outer peripheral surface of the middle portion of the rotating shaft. The rotary positioning mechanism is also radially movably connected to the lower end portions of the plurality of claw members. The rotary positioning mechanism includes an annular cover plate and an axial limiting buckle. An inwardly concave stepped hole is formed on the inner peripheral surface of the upper end portion of the cover plate. A bearing is embedded in the stepped hole. The bearing is simultaneously sleeved on the outer peripheral surface of the middle portion of the rotating shaft, and a first pressing ring and a second pressing ring are respectively in abutting fit with the upper end surface and the lower end surface thereof. The first pressing ring is clamped at the top of the stepped hole, and a plurality of bolt-nut assemblies are connected between the first pressing ring and the upper end portion of the cover plate. The second pressing ring and the axial limiting buckle are both sleeved on the outer peripheral surface of the rotating shaft. The upper end surface of the axial limiting buckle is in abutting fit with the lower end surface of the second pressing ring. The lower end surface of the axial limiting buckle is in abutting fit with the upper end surface of the power connector.

2. The internal hole rotary wrench according to claim 1, wherein, A first B-shaped pin shaft is horizontally penetrated through the lower end portion of each claw member. The first B-shaped pin shafts all penetrate through the upper end portion of the cover plate and are respectively locked with a first split pin.

3. The internal hole rotary wrench according to claim 2, characterized in that, Axial clamping grooves for accommodating the lower end portions of the claw members are respectively formed in a concave manner on the outer peripheral surface of the upper end portion of the cover plate.

4. The internal hole rotary wrench according to claim 2, characterized in that, The first B-shaped pin shafts are all perpendicular to the radial direction. Horizontally sliding holes for the first B-shaped pin shafts to pass through and move radially are respectively formed in the upper end portion of the cover plate.

5. The internal hole rotary wrench according to claim 1, wherein, The upper end portion of the power connector has a jack adapted to the lower end portion of the rotating shaft. The lower end portion of the power connector has a rectangular jack for connecting to an external power source. The rectangular jack and the jack are integrally and coaxially connected.

6. The internal hole rotary wrench according to claim 5, characterized in that, The lower end portion of the rotating shaft is inserted into the jack, and a second B-shaped pin shaft is radially penetrated through the lower end portion of the rotating shaft. The second B-shaped pin shaft penetrates through the upper end portion of the power connector and is locked with a second split pin.

7. The internal hole rotary wrench according to claim 1, characterized in that, A circular retaining ring is coaxially arranged on the upper end surface of the rotating shaft. A bolt is connected between the central position of the circular retaining ring and the rotating shaft.

8. The internal hole rotary wrench according to claim 1, characterized in that, There are four claw members.

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