Torque direct transmission type jaw air lift reverse circulation double-layer drill rod and manufacturing method thereof

Abstract

The torque direct transmission type jaw air lift reverse circulation double-layer drill rod comprises a plurality of double-layer drill rod sections which are connected up and down and provided with outer pipes, inner pipes and jaw sleeves, the outer pipes on the upper portion are inserted into the outer pipes on the lower portion, air channels are formed between the inner pipes and the outer pipes, and outer jaws are evenly distributed on the outer walls of connectors on the outer pipes in the circumferential direction; an inner jaw matched with the outer jaw is arranged on the inner side wall of the tooth nesting sleeve, so that the inner jaw abuts against the lower portion of the outer jaw in a staggered mode, the inner top wall of the tooth nesting sleeve abuts against the upper end face of the annular flange on the outer pipe, and lifting force can be transmitted; a regular prism hole is formed in the inner wall of an upper connector of an outer pipe, and a regular prism body located below an annular flange is formed on the outer wall of a lower connector of the outer pipe, so that the regular prism body is matched with the regular prism hole and inserted into the regular prism hole; torque can be directly transmitted through matching of the regular prism body and the regular prism hole, the torque transmission efficiency is high, the structure is simple, the machining difficulty is small, the cost is low, and the detaching and connecting efficiency is not affected. The manufacturing method provided by the invention is easy to implement and high in yield.

Description

Technical Field

[0001] The invention relates to the technical field of vertical shaft drilling rigs, and in particular to a torque direct transmission type tooth-engaged air lift reverse circulation double-layer drill pipe and a manufacturing method thereof. Background Art

[0002] As the diameter and depth of vertical shafts constructed in coal mines, gold mines, iron mines, lithium mines, infrastructure and other fields in China become larger and larger, the requirements for the lifting force and torque of vertical shaft drilling rigs using the drilling method are also getting higher and higher. The requirements for drill rods, which transmit lifting force and torque, are also increasing accordingly.

[0003] The drilling method uses air lift reverse circulation to remove slag, and it is necessary to input compressed air into the inner cavity of the drill pipe for air lift. The drill pipe with gas transmission structure can be roughly divided into three categories. The first category is the drill pipe with built-in air pipe, which uses an independent air pipe to deliver air. Since the air pipe is inserted in the center of the inner cavity of the drill pipe, it has a certain obstruction to the discharge of slag and mud in the inner cavity, and each time the drill pipe is disassembled and connected, the inserted air pipe needs to be disassembled and connected. The disassembly and assembly are cumbersome, time-consuming and labor-intensive, affecting the construction efficiency; the second category is the drill pipe with external air pipe, which delivers air through the connecting flange. The connecting flange has a complex structure, limited strength, and poor load transmission capacity. The flange is connected by bolts, and large-size high-strength The bolts of high degree need to be operated by people holding pneumatic wrenches, which has high labor intensity and low mechanization degree. Bolts and nuts are easy to fall into the shaft, affecting the drilling of the drill bit. The third type is a double-layer drill rod, which supplies air through the cavity between the inner and outer rods. For example, Chinese patent CN105756574A discloses this type of drill rod. The drill rod realizes axial fixation of adjacent drill rods through the outer teeth on the inner tube of the adjacent drill rods and the inner teeth on the outer tube. The lifting force is transmitted, and the circumferential fixation of adjacent drill rods is realized through the meshing of the outer gears on the upper and lower joints of the adjacent drill rods with the external inner gear sleeves to transmit torque. Such a structure has at least the following problems:

[0004] 1. The joint between the outer tube and the inner tube is a structure with an external external gear and an internal tooth embedment. The structure is complex and has a large number of teeth. In addition, the external gear needs to be aligned with the external tooth embedment / internal tooth embedment, which is difficult to process and has high cost.

[0005] 2. The transmission of torque needs to be transferred through the internal gear sleeve, which is not direct enough and the transmission efficiency is low.

[0006] 3. The outer gear and the inner gear sleeve are located at the outermost side and are in direct contact with the mud. The fine sand in the mud can easily enter the meshing surface, causing the outer gear and the inner gear sleeve to stick to each other, affecting the disassembly efficiency. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a torque direct transmission type tooth-engaged air lift reverse circulation double-layer drill pipe with a simple structure, low processing difficulty, low cost, high torque transmission efficiency, and no impact on disassembly efficiency. The present invention also provides a method for manufacturing a torque direct transmission type tooth-engaged air lift reverse circulation double-layer drill pipe that is easy to implement and has a high yield rate.

[0008] To achieve the above object, the product in the technical solution provided by the present invention is a torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe, comprising a plurality of double-layer drill pipe segments connected in sequence from top to bottom, wherein the double-layer drill pipe segments include:

[0009] An outer tube, the outer tube comprising an outer tube body, an outer tube upper joint coaxially connected to the upper end of the outer tube body, and an outer tube lower joint coaxially connected to the lower end of the outer tube body, wherein in adjacent double-layer drill pipe sections, the outer tube lower joint of the upper double-layer drill pipe section is inserted into the outer tube upper joint of the lower double-layer drill pipe section, and an outer wall of the outer tube lower joint is provided with an annular flange for limiting the insertion depth of the outer tube lower joint;

[0010] An inner tube, the inner tube is inserted into the outer tube, and an air passage for conveying compressed air is formed between the outer wall of the inner tube and the inner wall of the outer tube;

[0011] A tooth insert, the tooth insert being rotatably and slidably sleeved on the outer tube;

[0012] The outer wall of the outer tube upper joint is uniformly provided with external teeth along the circumferential direction, the upper edge of the external teeth is flush with the upper end surface of the outer tube upper joint, the inner side wall of the tooth nest is provided with an internal tooth nest matching the external teeth, the lower edge of the internal tooth nest is flush with the lower end surface of the tooth nest, the internal tooth nest is staggered and abutted directly below the external teeth nest, the inner top wall of the tooth nest is pressed against the upper end surface of the annular flange, and the adjacent double-layer drill pipe segments are locked in the axial direction to transmit the lifting force;

[0013] The projection of the inner wall of the outer tube upper joint in the up-down direction is a regular polygon, forming a regular prism hole whose edge is flush with the upper end face of the outer tube upper joint; the projection of the outer wall of the outer tube lower joint in the up-down direction is a regular polygon, forming a regular prism body whose lower edge is flush with the lower end face of the outer tube lower joint; the regular prism body is located below the annular flange, matches the regular prism hole and is inserted into the regular prism hole, locking the adjacent double-layer drill pipe segments in the circumferential direction to transmit torque.

[0014] Preferably, the axis centerline of the regular prism hole coincides with the axis centerline of the outer tube body.

[0015] Preferably, the regular prism hole is any one of a regular quadrangular prism hole, a regular pentagonal prism hole, a regular hexagonal prism hole, a regular heptagonal prism hole, and a regular octagonal prism hole.

[0016] Preferably, an annular welding positioning stop is provided at the connection between the outer tube body and the outer tube upper joint and the outer tube lower joint. The annular welding positioning stop is located on the inner wall of the outer tube body and expands outward. The lower end of the outer tube upper joint and the upper end of the outer tube lower joint are provided with an inward-retracted annular welding positioning enclosure. The annular welding positioning enclosure is inserted into the annular welding positioning stop and fits with the annular welding positioning stop.

[0017] Preferably, the inner tube includes an inner tube body coaxially inserted into the outer tube body, an inner tube upper joint coaxially connected to the upper end of the inner tube body, and an inner tube lower joint coaxially connected to the lower end of the inner tube body, the airway is formed between the outer wall of the inner tube body and the inner wall of the outer tube body, the upper end of the inner tube upper joint is fixedly connected to the inner wall of the outer tube upper joint, and the lower end surface of the inner tube lower joint is flush with the lower end surface of the outer tube lower joint.

[0018] Further preferably, the inner wall of the outer tube upper joint is provided with a step, and the step is located below the regular prism hole. The outer wall of the inner tube upper joint is provided with an annular skirt, and the outer wall of the annular skirt is sealedly connected to the vertical surface of the step, and the bottom wall of the annular skirt is abutted against the horizontal surface of the step, so that the annular skirt is placed on the step.

[0019] Further preferably, an annular groove is coaxially provided on the upper end face of the annular skirt, and an annular outer plate extending downward is provided at the bottom of the outer tube lower joint, and the annular outer plate is inserted into the annular groove, and the outer wall of the annular outer plate is dynamically sealed to the side wall of the annular groove.

[0020] Further preferably, the bottom wall of the annular groove is provided with a through hole extending downward, the through hole is connected to the airway, and there are multiple through holes evenly distributed along the axis of the annular groove.

[0021] Further preferably, the through hole is a waist-shaped hole extending along the circumferential direction of the annular groove.

[0022] Further preferably, in the adjacent double-layer drill pipe sections, the inner tube lower joint of the double-layer drill pipe section located on the upper side is inserted into the inner tube upper joint of the double-layer drill pipe section located on the lower side.

[0023] Further preferably, the lower end of the inner tube lower joint is provided with an annular inner enclosure plate, and the annular inner enclosure plate is inserted into the inner tube upper joint and dynamically sealed with the inner wall of the inner tube upper joint.

[0024] Further preferably, the upper end portion of the inner tube lower joint is retracted and inserted into the inner tube body.

[0025] Further preferably, the outer wall of the inner tube lower joint is connected with a positioning block extending outward, there are multiple positioning blocks and they are evenly distributed along the axis of the inner tube lower joint, and there is a gap between the outer end surface of the positioning block and the inner wall surface of the outer tube lower joint.

[0026] Further preferably, a plurality of rows of mixing gas holes are provided in the middle portion of the inner tube body of the bottom double-layer drill pipe segment, each row of the mixing gas holes has a plurality of mixing gas holes which are evenly distributed along the axis of the inner tube body, and the mixing gas holes are used to connect the airway and the inner cavity of the inner tube body.

[0027] Preferably, a downwardly extending through groove is formed on the upper end surface of the tooth embedment, the through groove is aligned with the tooth groove of the inner tooth embedment, the groove width of the through groove in the circumferential direction of the tooth embedment corresponds to the width of the tooth groove of the inner tooth embedment in the circumferential direction of the tooth embedment, and the tooth embedment also includes a pluggable locking plug plate inserted in the through groove, and the lower end of the locking plug plate extends downward into the tooth groove of the inner tooth embedment.

[0028] Further preferably, the outer side wall of the tooth embedment is provided with a threaded hole extending in the radial direction of the tooth embedment, the threaded hole is communicated with the through groove, and the threaded hole is used to connect a top screw that presses against the locking plug plate.

[0029] Further preferably, the upper end of the locking plug plate is connected to a handle seat for pressing against the upper end surface of the tooth insert, and the handle seat is connected to a handle for facilitating the insertion and removal of the locking plug plate.

[0030] To achieve the above object, the method in the technical solution provided by the present invention is a method for manufacturing the above torque direct transmission type toothed air lift reverse circulation double-layer drill pipe, comprising: manufacturing the double-layer drill pipe segment, connecting a plurality of double-layer drill pipe segments in sequence from top to bottom to obtain the torque direct transmission type toothed air lift reverse circulation double-layer drill pipe, characterized in that the manufacturing method of the double-layer drill pipe segment comprises:

[0031] S1. Construction preparation;

[0032] S2. Processing the inner tube body, the inner tube upper joint, the inner tube lower joint, the outer tube body, the outer tube upper joint, the outer tube lower joint, and the thread nesting according to the drawings;

[0033] S3. Weld the upper joint of the inner tube to the upper end of the inner tube body and weld the lower joint of the inner tube to the lower end of the inner tube body to obtain the inner tube; weld the upper joint of the outer tube to the upper end of the outer tube body to obtain component A;

[0034] S4. Insert the inner tube into the component A from top to bottom until the lower joint of the inner tube is exposed from the lower end of the component A, and weld at least three positioning blocks evenly distributed along the axis of the lower joint of the inner tube on the outer wall of the lower joint of the inner tube;

[0035] S5. Insert the tooth nest from the lower joint of the inner tube into the component A;

[0036] S6. Insert the outer tube lower joint along the positioning block from the lower end of the inner tube until the annular welding positioning enclosure at the upper end of the outer tube lower joint is inserted into the annular welding positioning stop at the lower end of the component A, and weld the joint between the outer tube lower joint and the component A from the outside to combine the outer tube lower joint and the component A into an outer tube;

[0037] S7. A sealing ring is placed on the upper joint of the inner tube, and the inner tube is continuously inserted downward until the annular skirt of the upper joint of the inner tube is pressed against the step on the inner wall of the upper joint of the outer tube, and the joint of the annular skirt and the step is welded from above to fix the inner tube and the outer tube;

[0038] S8. A sealing ring is set on the lower joint of the inner tube and the lower joint of the outer tube to form a double-layer drill pipe segment;

[0039] S9. Make a plurality of double-layer drill pipe segments and conduct disassembly and assembly tests for interchangeability of upper and lower connections, and remove defective products;

[0040] S10. Complete the production of the double-layer drill pipe segments.

[0041] Preferably, the processing in step S2 includes rolling, turning, boring, grinding, welding, and heat treatment, and after processing, it also includes a step of correcting the size.

[0042] Preferably, before welding, the method further includes a step of preheating the welding part, and after welding, the method further includes a step of flaw detection on the weld.

[0043] Due to the application of the above technical solution, the torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe provided by the present invention has the following advantages compared with the prior art:

[0044] 1. By arranging external teeth uniformly distributed along the circumferential direction on the outer wall of the outer tube upper joint and arranging internal teeth matching the external teeth on the inner wall of the teeth nest, the upper edge of the external teeth is flush with the upper end face of the outer tube upper joint, the lower edge of the internal teeth is flush with the lower end face of the teeth nest, the internal teeth are displaced and abutted directly below the external teeth, and the inner top wall of the teeth nest is tightly abutted against the upper end face of the annular flange, the adjacent double-layer drill pipe segments can be locked in the axial direction to transmit the lifting force.

[0045] 2. By making the projection of the inner wall of the outer tube upper joint in the up-down direction into a regular polygon and forming a regular prism hole whose edge is flush with the upper end face of the outer tube upper joint, by making the projection of the outer wall of the outer tube lower joint in the up-down direction into a regular polygon and forming a regular prism whose lower edge is flush with the lower end face of the outer tube lower joint, the regular prism is located below the annular flange, the regular prism is matched with the regular prism hole and inserted in the regular prism hole, the adjacent double-layer drill pipe segments can be locked in the circumferential direction, and the torque can be directly transmitted by the cooperation of the regular prism and the regular prism hole without transfer, and the torque transmission efficiency is high.

[0046] 3. The upper joint of the outer tube has an outer tooth embedment and an inner regular prism hole structure. The lower joint of the outer tube is not provided with a tooth embedment or a gear, but only with a regular prism structure. The upper and lower joints of the inner tube are not provided with a tooth embedment or a gear. The structure of each joint is simpler. Since the inner tooth embedment is arranged on the inner side wall of the tooth embedment, and the tooth embedment can rotate relative to the outer tube, the outer tooth embedment and the inner regular prism hole of the upper joint of the outer tube do not need to be aligned, and the processing difficulty of each joint is small and the cost is low.

[0047] 4. After the right prism hole and the right prism body are matched, the whole is located on the inner side of the outer tube and is not in direct contact with the mud. The fine sand in the mud is not easy to enter the matching surface between the right prism hole and the right prism body. Moreover, the matching surface between the right prism hole and the right prism body is relatively straighter. Even if a small amount of fine sand enters, it is not easy to form adhesion and does not affect the disassembly efficiency.

[0048] Due to the application of the above technical solution, the manufacturing method of the above torque direct transmission type tooth-engaged air lift reverse circulation double-layer drill pipe provided by the present invention has the following advantages compared with the prior art:

[0049] The manufacturing method of first inserting the inner tube into the component A composed of the outer tube upper joint and the outer tube body, and then inserting the outer tube lower joint for welding can avoid the impact of the inner tube lower joint on the welding part of the outer tube lower joint and the outer tube body when the inner tube lower joint is inserted into the tube, and will not cause hidden cracks in the welding part of the outer tube lower joint and the outer tube body from the inside, and will not cause deformation of the inner tube lower joint; the method of first welding a positioning block on the outer wall of the inner tube lower joint, and then inserting the outer tube lower joint along the positioning block can facilitate the welding of the positioning block, and can also use the positioning block to guide the outer tube lower joint, so as to facilitate the alignment of the outer tube lower joint and the outer tube body; it is easy to implement and has a high yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a three-dimensional schematic diagram of the segmentation of a single double-layer drill pipe in the present invention.

[0051] Figure 2 It is a schematic axial cross-sectional view of a plurality of double-layer drill pipes connected in sections in the present invention.

[0052] Figure 3 yes Figure 2A local enlarged schematic diagram of point A in the middle.

[0053] Figure 4 yes Figure 2 A local enlarged schematic diagram of point B in the middle.

[0054] Figure 5 yes Figure 2 Schematic top view of .

[0055] Figure 6 yes Figure 2 Schematic diagram of the top view.

[0056] Figure 7 yes Figure 2 A three-dimensional schematic diagram of the joints on the middle and outer tubes.

[0057] Figure 8 yes Figure 2 A three-dimensional schematic diagram of the lower joint of the middle and outer pipes.

[0058] Fig. 9 yes Figure 2 Schematic diagram of the central tooth insertion.

[0059] Fig.10 It is a flow chart for making the single double-layer drill pipe segmentation in the present invention.

[0060] Among them: 11. Outer tube body; 111. Annular welding positioning stop; 12. Outer tube upper joint; 121. External tooth embedment; 122. Hexagonal prism hole; 123. First annular welding positioning enclosure; 124. Step; 13. Outer tube lower joint; 131. Annular flange; 132. Hexagonal prism body; 133. Second annular welding positioning enclosure; 134. Annular outer plate; 21. Inner tube body; 211. Mixing gas hole; 22. Inner tube upper joint; 221. Annular skirt; 222. Annular groove; 223. Through hole; 23. Inner tube lower joint; 231. Annular inner enclosure; 232. Positioning block; 233. Gap; 24. Airway; 30. Thread embedment; 31. Internal tooth embedment; 311. Tooth groove; 32. Through groove; 33. Locking plug plate; 331. Handle seat; 332. Handle; 34. Threaded hole. DETAILED DESCRIPTION

[0061] like Figures 1 to 9As shown, the torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe provided by the present invention comprises a plurality of double-layer drill pipe segments connected in sequence from top to bottom, the double-layer drill pipe segments comprising: an outer tube, an inner tube, and a tooth-engaged nest 30, wherein the outer tube comprises an outer tube body 11, an outer tube upper joint 12 coaxially connected to the upper end of the outer tube body 11, and an outer tube lower joint 13 coaxially connected to the lower end of the outer tube body 11, in adjacent double-layer drill pipe segments, the outer tube lower joint 13 of the upper double-layer drill pipe segment is inserted into the outer tube upper joint 12 of the lower double-layer drill pipe segment, and the outer wall of the outer tube lower joint 13 is provided with a portion for limiting the outer tube lower joint 11. 3; the inner tube is inserted into the outer tube, and the inner tube includes an inner tube body 21 coaxially inserted into the outer tube body 11, an inner tube upper joint 22 coaxially connected to the upper end of the inner tube body 21, and an inner tube lower joint 23 coaxially connected to the lower end of the inner tube body 21, an airway 24 for conveying compressed air is formed between the outer wall of the inner tube body 21 and the inner wall of the outer tube body 11, the upper end of the inner tube upper joint 22 is fixedly connected to the inner wall of the outer tube upper joint 12, and the lower end surface of the inner tube lower joint 23 is flush with the lower end surface of the outer tube lower joint 13; the tooth insert 30 is rotatably and slidably sleeved on the outer tube.

[0062] In this embodiment, the outer wall of the outer tube upper joint 12 is uniformly provided with outer tooth inserts 121 along the circumferential direction, the upper edge of the outer tooth insert 121 is flush with the upper end surface of the outer tube upper joint 12, the inner side wall of the tooth insert 30 is provided with an inner tooth insert 31 matching the outer tooth insert, the lower edge of the inner tooth insert 31 is flush with the lower end surface of the tooth insert 30, the inner tooth insert 31 is staggered and abutted directly below the outer tooth insert 121, the inner top wall of the tooth insert 30 is pressed against the upper end surface of the annular flange 131, and the adjacent double-layer drill pipe segments are locked in the axial direction to transmit the lifting force; the inner wall of the outer tube upper joint 12 is provided with an inner tooth insert 31 matching the outer tooth insert, the lower edge of the inner tooth insert 31 is flush with the lower end surface of the tooth insert 30, the inner tooth insert 31 is staggered and abutted directly below the outer tooth insert 121, and the inner top wall of the tooth insert 30 is pressed against the upper end surface of the annular flange 131, and the adjacent double-layer drill pipe segments are locked in the axial direction to transmit the lifting force; The projection of the wall in the up-down direction is a regular hexagon, forming a regular hexagonal prism hole 122 whose edge is flush with the upper end face of the outer tube upper joint 12. The projection of the outer wall of the outer tube lower joint 13 in the up-down direction is a regular hexagon, forming a regular hexagonal prism body 132 whose lower edge is flush with the lower end face of the outer tube lower joint 13. The regular hexagonal prism body 132 is located below the annular flange 131. The regular hexagonal prism body 132 matches the regular hexagonal prism hole 122 and is inserted into the regular hexagonal prism hole 122, locking the adjacent double-layer drill pipe segments in the circumferential direction to transmit torque.

[0063] The advantages of this setting are:

[0064] The transmission of lifting force and torque can be realized, and the torque can be directly transmitted by utilizing the cooperation between the regular hexagonal prism and the regular hexagonal prism hole without transfer, and the torque transmission efficiency is high; at the same time, the upper joint of the outer tube is a structure of external tooth embedment and internal regular hexagonal prism hole, the lower joint of the outer tube is not provided with tooth embedment and gear, only with regular hexagonal prism structure, and the upper and lower joints of the inner tube are not provided with tooth embedment and gear, and the structure of each joint is simpler, because the internal tooth embedment is arranged on the inner side wall of the tooth embedment, and the tooth embedment can rotate relative to the outer tube, the external tooth embedment and the internal regular prism hole of the upper joint of the outer tube do not need to be aligned, and the processing difficulty of each joint is small and the cost is low; in addition, after the regular hexagonal prism hole and the regular hexagonal prism are matched, the whole is located on the inner side of the outer tube, and is not in direct contact with the mud, and the fine sand in the mud is not easy to enter the matching surface between the regular hexagonal prism hole and the regular hexagonal prism, and further, the matching surface between the regular hexagonal prism hole and the regular hexagonal prism is relatively straighter, and even if a small amount of fine sand enters, it is not easy to form adhesion, and the disassembly efficiency is not affected.

[0065] To ensure the stability of torque transmission, in this embodiment, the axis line of the regular hexagonal prism hole 122 coincides with the axis line of the outer tube body 11. In other embodiments, the regular hexagonal prism hole 122 can also be any one of a regular quadrangular prism hole, a regular pentagonal prism hole, and a regular octagonal prism hole.

[0066] To facilitate plug-in and positioning, in the present embodiment, an annular welding positioning stop 111 is provided at the connection between the outer tube body 11 and the outer tube upper joint 12 and the outer tube lower joint 13. The annular welding positioning stop 111 is located on the inner wall of the outer tube body 11 and expands outward. The lower end of the outer tube upper joint 12 is provided with a first annular welding positioning enclosure 123 that is retracted inward, and the upper end of the outer tube lower joint 13 is provided with a second annular welding positioning enclosure 133 that is retracted inward. During plug-in, the first annular welding positioning enclosure 123 is inserted downward into the annular welding positioning stop 111 at the upper end of the outer tube body 11 and fits with the annular welding positioning stop 111, and the second annular welding positioning enclosure 133 is inserted upward into the annular welding positioning stop 111 at the lower end of the outer tube body 11 and fits with the annular welding positioning stop 111. After the plug-in is completed, the connection between the outer tube body 11 and the outer tube upper joint 12 and the outer tube lower joint 13 is achieved by welding.

[0067] To facilitate the positioning of the inner tube and facilitate connection, in the present embodiment, the inner wall of the outer tube upper joint 12 is provided with a step 124, and the step 124 is located below the regular prism hole 122. The outer wall of the inner tube upper joint 22 is provided with an annular skirt 221. The outer wall of the annular skirt 221 is sealed with the vertical surface of the step 124, and the bottom wall of the annular skirt 221 is abutted with the horizontal surface of the step 124, so that the annular skirt 221 is overlapped on the step 124. After the overlap is completed, the connection between the inner tube upper joint 22 and the outer appearance upper joint 12 is achieved by welding the top surface of the annular skirt 221 to the upper edge of the step 124, so that the inner tube and the outer appearance 10 are connected as one.

[0068] In this embodiment, the lower end of the inner tube upper joint 22 is retracted and inserted downward into the inner tube body 21, and the upper end of the inner tube lower joint 23 is retracted and inserted upward into the inner tube body 21. After the insertion is completed, the connection between the inner tube body 21 and the inner tube upper joint 22 and the inner tube lower joint 23 is achieved by welding.

[0069] In adjacent double-layer drill pipe segments, the inner tube lower joint 23 of the upper double-layer drill pipe segment is inserted into the inner tube upper joint 22 of the lower double-layer drill pipe segment. To facilitate plug-in, preferably, an annular inner enclosure plate 231 is provided at the lower end of the inner tube lower joint 23. The upper annular inner enclosure plate 231 is inserted into the inner tube upper joint 22 and is dynamically sealed with the inner wall of the inner tube upper joint 22.

[0070] In order to clear the air passages of adjacent double-layer drill pipe segments and prevent mud from entering, in the present embodiment, an annular groove 222 is coaxially provided on the upper end face of the annular skirt 221, and an annular outer plate 134 extending downward is provided at the bottom of the outer tube lower joint 13. The annular outer plate 134 is inserted into the annular groove 222, and the outer wall of the annular outer plate 134 is dynamically sealed with the side wall of the annular groove 222. At the same time, a through hole 223 extending downward is provided on the bottom wall of the annular groove 222, and the through hole 223 is connected with the air passage 24. There are multiple through holes 223 and they are evenly distributed along the axial line of the annular groove 222. The through holes 223 are preferably waist-shaped holes extending in the circumferential direction of the annular groove 222.

[0071] In this embodiment, the outer wall of the inner tube lower joint 23 is connected to a positioning block 232 extending outward, and there are multiple positioning blocks 232 that are evenly distributed along the axial line of the inner tube lower joint 23. There is a gap 233 between the outer end surface of the positioning block 232 and the inner wall surface of the annular outer plate 231 at the lower end of the outer tube lower joint 13. The positioning block 232 is not only used for guiding and positioning, but also for enhancing the strength of the airway 24 to prevent the airway 24 from being crushed.

[0072] In this embodiment, a plurality of rows of mixing gas holes 211 are provided in the middle of the inner tube body 21 of the bottom double-layer drill pipe segment. Each row of mixing gas holes 211 has a plurality of mixing gas holes 211 and are evenly distributed along the axis of the inner tube body 21. The mixing gas holes 211 are used to connect the airway 24 and the inner cavity of the inner tube body 21.

[0073] To facilitate fixation, in the present embodiment, a downwardly extending through groove 32 is formed on the upper end surface of the tooth embedment 30, and the through groove 32 is aligned with the tooth groove 311 of the inner tooth embedment 31. The groove width of the through groove 32 in the circumferential direction of the tooth embedment 32 corresponds to the width of the tooth groove 311 of the inner tooth embedment 31 in the circumferential direction of the tooth embedment 30. The tooth embedment 32 also includes a pluggable locking plug plate 33 inserted in the through groove 32, and the lower end of the locking plug plate 33 extends downward into the tooth groove 311 of the inner tooth embedment 31. To prevent the locking plug plate 33 from loosening, the outer side wall of the tooth embedment 30 is further provided with a threaded hole 34 extending in the radial direction of the tooth embedment 30, and the threaded hole 34 is connected to the through groove 32, and the threaded hole 34 is used to connect the top screw that presses against the locking plug plate 33.

[0074] To facilitate insertion and removal and positioning, in this embodiment, the upper end of the locking plug plate 33 is connected to a handle seat 331 for pressing against the upper end surface of the tooth nest 30, and the handle seat 331 is connected to a handle 332 for easy insertion and removal of the locking plug plate 33.

[0075] like Fig.10 As shown, the manufacturing method of the above-mentioned torque direct transmission type toothed air lift reverse circulation double-layer drill pipe provided by the present invention comprises: manufacturing double-layer drill pipe segments, connecting multiple double-layer drill pipe segments in sequence from top to bottom to obtain the torque direct transmission type toothed air lift reverse circulation double-layer drill pipe, and the manufacturing method of the double-layer drill pipe segments comprises:

[0076] S1. Construction preparation;

[0077] S2. Process the inner tube body, the inner tube upper joint, the inner tube lower joint, the outer tube body, the outer tube upper joint, the outer tube lower joint, and the thread embedding according to the drawings;

[0078] S3. The inner tube upper joint is welded to the upper end of the inner tube body, and the inner tube lower joint is welded to the lower end of the inner tube body to obtain the inner tube; the outer tube upper joint is welded to the upper end of the outer tube body to obtain component A;

[0079] S4. Insert the inner tube into component A from top to bottom until the lower joint of the inner tube is exposed from the lower end of component A, and weld at least three positioning blocks evenly distributed along the axis of the lower joint of the inner tube on the outer wall of the lower joint of the inner tube;

[0080] S5. Insert the tooth insert from the lower joint of the inner tube into component A;

[0081] S6. Insert the outer tube lower joint along the positioning block from the lower end of the inner tube until the annular welding positioning enclosure at the upper end of the outer tube lower joint is inserted into the annular welding positioning stop at the lower end of component A, and weld the joint between the outer tube lower joint and component A from the outside to combine the outer tube lower joint and component A into the outer tube;

[0082] S7. Put a sealing ring on the upper joint of the inner tube, and continue to insert the inner tube until the annular skirt of the upper joint of the inner tube is close to the step on the inner wall of the upper joint of the outer tube, and weld the joint of the annular skirt and the step from above to fix the inner tube and the outer tube;

[0083] S8. Sealing rings are placed on the lower joints of the inner tube and the outer tube to form double-layer drill pipe sections;

[0084] S9. Make multiple double-layer drill pipe segments and conduct disassembly and assembly tests for interchangeability of upper and lower connections, and remove defective products;

[0085] S10. Complete the production of double-layer drill pipe segments.

[0086] The manufacturing method of first inserting the inner tube into the component A composed of the outer tube upper joint and the outer tube body, and then inserting the outer tube lower joint for welding can avoid the impact of the inner tube lower joint on the welding part of the outer tube lower joint and the outer tube body when the inner tube lower joint is inserted into the tube, and will not cause hidden cracks in the welding part of the outer tube lower joint and the outer tube body from the inside, and will not cause deformation of the inner tube lower joint; the method of first welding a positioning block on the outer wall of the inner tube lower joint, and then inserting the outer tube lower joint along the positioning block can facilitate the welding of the positioning block, and can also use the positioning block to guide the outer tube lower joint, so as to facilitate the alignment of the outer tube lower joint and the outer tube body; it is easy to implement and has a high yield rate.

[0087] Preferably, the processing in step S2 includes rolling, turning, boring, grinding, welding, and heat treatment, and after processing, it also includes a step of correcting the size.

[0088] Preferably, before welding, the method further includes a step of preheating the welding part, and after welding, the method further includes a step of flaw detection on the weld.

[0089] It should be noted that, in the present invention, "seal" and "dynamic seal" are preferably achieved by the cooperation of a seal ring groove and a seal ring.

[0090] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A torque direct transmission type toothed air lift reverse circulation double-layer drill pipe, comprising a plurality of double-layer drill pipe segments connected in sequence from top to bottom, the double-layer drill pipe segments comprising: An outer tube, the outer tube comprising an outer tube body, an outer tube upper joint coaxially connected to the upper end of the outer tube body, and an outer tube lower joint coaxially connected to the lower end of the outer tube body, wherein in adjacent double-layer drill pipe sections, the outer tube lower joint of the upper double-layer drill pipe section is inserted into the outer tube upper joint of the lower double-layer drill pipe section, and an outer wall of the outer tube lower joint is provided with an annular flange for limiting the insertion depth of the outer tube lower joint; An inner tube, the inner tube is inserted into the outer tube, and an air passage for conveying compressed air is formed between the outer wall of the inner tube and the inner wall of the outer tube; A tooth insert, the tooth insert being rotatably and slidably sleeved on the outer tube; Features: The outer wall of the outer tube upper joint is uniformly provided with external teeth along the circumferential direction, the upper edge of the external teeth is flush with the upper end surface of the outer tube upper joint, the inner side wall of the tooth nest is provided with an internal tooth nest matching the external teeth, the lower edge of the internal tooth nest is flush with the lower end surface of the tooth nest, the internal tooth nest is staggered and abutted directly below the external teeth nest, the inner top wall of the tooth nest is pressed against the upper end surface of the annular flange, and the adjacent double-layer drill pipe segments are locked in the axial direction to transmit the lifting force; The projection of the inner wall of the outer tube upper joint in the up-down direction is a regular polygon, forming a regular prism hole whose edge is flush with the upper end face of the outer tube upper joint; the projection of the outer wall of the outer tube lower joint in the up-down direction is a regular polygon, forming a regular prism body whose lower edge is flush with the lower end face of the outer tube lower joint; the regular prism body is located below the annular flange, matches the regular prism hole and is inserted into the regular prism hole, locking the adjacent double-layer drill pipe segments in the circumferential direction to transmit torque.

2. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 1, characterized in that: The axis center line of the regular prism hole coincides with the axis center line of the outer tube body.

3. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 1, characterized in that: The regular prism hole is any one of a regular quadrangular prism hole, a regular pentagonal prism hole, a regular hexagonal prism hole, and a regular octagonal prism hole.

4. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 1, characterized in that: An annular welding positioning stop is provided at the connection between the outer tube body and the outer tube upper joint and the outer tube lower joint. The annular welding positioning stop is located on the inner wall of the outer tube body and expands outward. The lower end of the outer tube upper joint and the upper end of the outer tube lower joint are provided with an inward-retracted annular welding positioning enclosure. The annular welding positioning enclosure is inserted into the annular welding positioning stop and fits with the annular welding positioning stop.

5. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 1, characterized in that: The inner tube includes an inner tube body coaxially inserted into the outer tube body, an inner tube upper joint coaxially connected to the upper end of the inner tube body, and an inner tube lower joint coaxially connected to the lower end of the inner tube body. The airway is formed between the outer wall of the inner tube body and the inner wall of the outer tube body. The upper end of the inner tube upper joint is fixedly connected to the inner wall of the outer tube upper joint, and the lower end surface of the inner tube lower joint is flush with the lower end surface of the outer tube lower joint.

6. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 5, characterized in that: The inner wall of the outer tube upper joint is provided with a step, and the step is located below the regular prism hole. The outer wall of the inner tube upper joint is provided with an annular skirt, and the outer wall of the annular skirt is sealed and connected to the vertical surface of the step. The bottom wall of the annular skirt abuts against the horizontal surface of the step, so that the annular skirt is placed on the step.

7. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 6, characterized in that: The upper end surface of the annular skirt is coaxially provided with an annular groove, and the bottom of the outer tube lower joint is provided with an annular outer plate extending downward, the annular outer plate is inserted into the annular groove, and the outer wall of the annular outer plate is dynamically sealed with the side wall of the annular groove.

8. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 7, characterized in that: The bottom wall of the annular groove is provided with a through hole extending downwards, the through hole is communicated with the airway, and there are a plurality of through holes which are evenly distributed along the axis of the annular groove.

9. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 8, characterized in that: The through hole is a waist-shaped hole extending along the circumferential direction of the annular groove.

10. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 5, characterized in that: In the adjacent double-layer drill pipe sections, the inner pipe lower joint of the double-layer drill pipe section located on the upper side is inserted into the inner pipe upper joint of the double-layer drill pipe section located on the lower side.

11. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 10, characterized in that: An annular inner enclosure plate is disposed at the lower end of the inner tube lower joint, and the annular inner enclosure plate is inserted into the inner tube upper joint and dynamically sealed with the inner wall of the inner tube upper joint.

12. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 5, characterized in that: The upper end portion of the inner tube lower joint is retracted and inserted into the inner tube body.

13. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 5, characterized in that: The outer wall of the inner tube lower joint is connected with a positioning block extending outward, there are a plurality of positioning blocks which are evenly distributed along the axis of the inner tube lower joint, and there is a gap between the outer end surface of the positioning block and the inner wall surface of the outer tube lower joint.

14. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 5, characterized in that: A plurality of rows of mixing gas holes are provided in the middle of the inner tube body of the bottom double-layer drill pipe segment. Each row of the mixing gas holes has a plurality of mixing gas holes that are evenly distributed along the axis of the inner tube body. The mixing gas holes are used to connect the airway and the inner cavity of the inner tube body.

15. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 1, characterized in that: The upper end surface of the tooth embedding is provided with a through groove extending downward, the through groove is aligned with the tooth groove of the inner tooth embedding, the groove width of the through groove in the circumferential direction of the tooth embedding corresponds to the width of the tooth groove of the inner tooth embedding in the circumferential direction of the tooth embedding, and the tooth embedding also includes a pluggable locking plug plate inserted in the through groove, and the lower end of the locking plug plate extends downward into the tooth groove of the inner tooth embedding.

16. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 15, characterized in that: The outer side wall of the tooth nest is provided with a threaded hole extending in the radial direction of the tooth nest, the threaded hole is communicated with the through groove, and the threaded hole is used to connect the top screw that presses against the locking plug plate.

17. The torque direct transmission tooth-engaged air lift reverse circulation double-layer drill pipe according to claim 15, characterized in that: The upper end of the locking plug plate is connected to a handle seat for pressing against the upper end surface of the tooth insert, and the handle seat is connected to a handle for facilitating the insertion and removal of the locking plug plate.

18. A method for manufacturing the torque direct transmission type toothed air lift reverse circulation double-layer drill pipe according to any one of claims 5 to 14, comprising: The double-layer drill pipe segment is manufactured, and a plurality of double-layer drill pipe segments are sequentially connected from top to bottom to obtain the torque direct transmission type tooth-engaged air lift reverse circulation double-layer drill pipe, characterized in that the manufacturing method of the double-layer drill pipe segment includes: S1. Construction preparation; S2. Processing the inner tube body, the inner tube upper joint, the inner tube lower joint, the outer tube body, the outer tube upper joint, the outer tube lower joint, and the thread nesting according to the drawings; S3. Weld the upper joint of the inner tube to the upper end of the inner tube body and weld the lower joint of the inner tube to the lower end of the inner tube body to obtain the inner tube; weld the upper joint of the outer tube to the upper end of the outer tube body to obtain component A; S4. Insert the inner tube into the component A from top to bottom until the lower joint of the inner tube is exposed from the lower end of the component A, and weld at least three positioning blocks evenly distributed along the axis of the lower joint of the inner tube on the outer wall of the lower joint of the inner tube; S5. Insert the tooth nest from the lower joint of the inner tube into the component A; S6. Insert the outer tube lower joint along the positioning block from the lower end of the inner tube until the annular welding positioning enclosure at the upper end of the outer tube lower joint is inserted into the annular welding positioning stop at the lower end of the component A, and weld the joint between the outer tube lower joint and the component A from the outside to combine the outer tube lower joint and the component A into an outer tube; S7. A sealing ring is placed on the upper joint of the inner tube, and the inner tube is continuously inserted downward until the annular skirt of the upper joint of the inner tube is pressed against the step on the inner wall of the upper joint of the outer tube, and the joint of the annular skirt and the step is welded from above to fix the inner tube and the outer tube; S8. A sealing ring is set on the lower joint of the inner tube and the lower joint of the outer tube to form a double-layer drill pipe segment; S9. Make a plurality of double-layer drill pipe segments and conduct disassembly and assembly tests for interchangeability of upper and lower connections, and remove defective products; S10. Complete the production of the double-layer drill pipe segments.

19. The method according to claim 18, characterized in that: The processing in step S2 includes rolling, turning, boring, grinding, welding, and heat treatment, and after processing, it also includes a step of correcting the size.

20. The manufacturing method according to claim 18, characterized in that: Before welding, the process also includes the step of preheating the welding area, and after welding, the process also includes the step of flaw detection on the weld.

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