PDC (Polycrystalline Diamond Compact) drill bit capable of automatically replacing teeth underground and replacement method

Abstract

The invention relates to the technical field of well drilling tools, and particularly discloses a PDC drill bit capable of automatically replacing teeth underground and a replacing method.The PDC drill bit comprises a drill bit body, blades are arranged on the outer wall of the drill bit body, and cutting teeth are arranged on the blades; mounting cavities are formed in the blades, and the mounting cavities are communicated with the cavity in the drill bit main body; a plurality of positioning through grooves are formed in the side walls of the cutter wings, the positioning through grooves correspond to the cutting teeth one to one, and positioning clamping grooves are formed in the inner walls of the positioning through grooves; the cutting teeth are installed in the positioning through grooves through locking assemblies. The locking assembly comprises a positioning column, and the positioning column can be embedded into or moved out of the positioning clamping groove through the locking assembly. And a replacement assembly is arranged in the mounting cavity and comprises a storage unit for collecting old cutting teeth, a storage unit for storing new cutting teeth, and a driving assembly for driving the old cutting teeth to enter the storage unit and fixing the new cutting teeth in the positioning clamping groove. According to the invention, the cutting teeth of the PDC drill bit can be automatically replaced once underground, so that the tripping frequency is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling tools, and particularly relates to a PDC bit with automatic downhole tooth replacement and a replacement method. Background Art

[0002] A PDC bit is a kind of downhole drilling tool that is currently most widely used, mainly used for rock breaking during drilling, and some are also used in surface operations (such as mining, rescue, etc.).

[0003] The PDC bit mainly includes a bit body. One end of the bit body is connected to a drill pipe through a connecting part, and a plurality of cutter wings are arranged on the outer wall of the other end. A row of cutting teeth is arranged on the cutter wings. During drilling, the cutting teeth bite into the rock and soil to achieve rock breaking. When the PDC bit is in use, the cutting teeth are greatly worn and need to be replaced regularly. The existing replacement method is to lift the drill to take the PDC bit out of the ground for manual operation and replacement. For example, in CN221032437U, a PDC bit convenient for tooth replacement, and CN220395616U, a PDC bit for oil drilling convenient for tooth replacement, etc., all need to lift the drill to take the PDC bit out of the ground to operate and replace the cutting teeth of the PDC bit.

[0004] During the drilling process, the PDC bit is lowered into the well together with the drill pipe and other drilling tools. When encountering complex formations, the service life of the cutting teeth of the PDC bit will be significantly reduced. If the drill is lifted for replacement according to the service life of the cutting teeth, it will lead to frequent tripping in and out, which is not only troublesome to operate, increases the construction period, but also may cause other engineering problems during the frequent tripping in and out process.

[0005] If the cutting teeth of the PDC bit can be replaced once downhole, the influence of the formation on tripping in and out can be reduced, and the cutting teeth of the PDC bit and other drilling tools can be replaced or maintained simultaneously during one drill lift, reducing the frequency of tripping in and out. Summary of the Invention

[0006] The purpose of the present invention is to provide a PDC bit with automatic downhole tooth replacement and a replacement method, so as to realize automatic downhole replacement of the cutting teeth of the PDC bit once, and reduce the frequency of tripping in and out.

[0007] The present invention is realized through the following technical solutions: A PDC bit with automatic downhole tooth replacement includes a bit body. A plurality of cutter wings are arranged on the outer wall of the bit body, and cutting teeth are arranged on the cutter wings; an installation cavity is arranged inside the cutter wing, and the installation cavity is communicated with the cavity inside the bit body; A plurality of positioning through grooves are arranged on the side wall of the cutter wing, and the positioning through grooves correspond to the cutting teeth one by one. A positioning card slot is arranged on the inner wall of the positioning through groove; The cutting teeth are detachably fixed in the positioning through groove by means of a locking assembly and external force; the locking assembly includes a positioning post, and the locking assembly can embed or remove the positioning post from the positioning card slot; A replacement assembly is arranged in the installation cavity. The replacement assembly includes a storage unit for collecting the old cutting teeth, a storage unit storing new cutting teeth, and a driving assembly for driving the old cutting teeth into the storage unit and fixing the new cutting teeth in the positioning card slot.

[0008] In the prior art, when replacing the teeth of a PDC bit, the PDC bit needs to be removed from the well and replaced manually on the ground. However, since the replacement frequencies of the cutting teeth of the PDC bit and other drilling tools are different, when the cutting teeth of the PDC bit need to be replaced, other drilling tools do not necessarily need to be replaced. Based on this, the original intention of the present invention is as follows: By redesigning the PDC bit, the cutting teeth can be automatically replaced once in the well, so that the cutting teeth and other drilling tools are removed from the well for replacement at the same frequency, and ultimately the frequency of tripping in the drilling operation is reduced.

[0009] Compared with the prior art, the present invention has the following three main improvements: 1) In the prior art, the cutting teeth of the PDC bit are fixed on the blade by means of glue and heat treatment process. When the teeth need to be replaced, the cured glue needs to be knocked out and then the cutting teeth are taken out. However, the cutting teeth of the present invention are detachably installed on the side wall of the blade. Mainly, external force is used to realize the displacement of the cutting teeth in the positioning through groove on the blade. When the positioning post moves to a position corresponding to the positioning card slot, under the action of the locking assembly, the positioning post is pushed into the positioning card slot, and the engagement of the positioning post and the positioning card slot restricts the displacement of the cutting teeth, thereby realizing the fixation of the cutting teeth; when the cutting teeth need to be pulled out, the cutting teeth can be pulled out by external force (external force in the opposite direction to the pushing direction). The external force of the present invention includes the magnetic adsorption force generated by electrification or the power provided by other telescopic members.

[0010] 2) The blade of the prior PDC bit is a solid structure arranged on the outer wall of the bit body. A row of mounting holes is arranged on one rib of the blade, and the open ends of the mounting holes face outwards. The cutting teeth are installed through the open ends of the mounting holes. However, in order to realize the automatic replacement of the cutting teeth underground in the present invention, an installation cavity for installing the replacement assembly is arranged in the blade, and the installation cavity is communicated with the cavity in the bit body to facilitate the better installation of the replacement assembly.

[0011] 3) Compared with the prior art, in order to realize the automatic replacement of the cutting teeth underground in the present invention, a replacement assembly is added. Through the arranged replacement assembly, the old cutting teeth can be recovered into the installation cavity, and the stored new cutting teeth can be pushed into the positioning through groove.

[0012] In summary, the present invention can achieve automatic replacement of the cutting teeth of a PDC bit underground once, so as to reduce the frequency of tripping in and out of the well.

[0013] In a preferred embodiment, one end of the cutting tooth is a solid part, and a hollow part is provided at the other end; The locking assembly is installed in the hollow part. The locking assembly includes two adjusting rods. One end of the adjusting rod is hinged in the hollow part, and the other end is connected to the positioning column. The two adjusting rods are connected by a third spring; The side wall of the hollow part is provided with a guiding through groove for passing through the positioning column.

[0014] After the cutting tooth is fixed in the positioning through groove, all or part of the solid part of the cutting tooth protrudes from the cutter blade for biting into the rock and soil during the drilling process.

[0015] After the cutting tooth is inserted into the positioning through groove, under the extrusion of the side wall of the positioning through groove, the positioning column will not protrude from the outer wall of the cutting tooth. When the cutting tooth moves to a position where the positioning column corresponds to the positioning card slot, under the restoring force of the third spring, the positioning column extends out of the guiding through groove and is embedded in the positioning card slot to realize the fixation of the cutting tooth.

[0016] In a preferred embodiment, a fifth magnetic attracting block is provided at the other end of the adjusting rod. When energized, there is an attracting force between the two fifth magnetic attracting blocks.

[0017] The present invention can use the adsorption effect of the two fifth magnetic attracting blocks to retract the positioning column. Compared with directly pulling out the cutting tooth by external force, it is easier to first use the adsorption effect of the two fifth magnetic attracting blocks to retract the positioning column and then pull out the cutting tooth by external force.

[0018] In a preferred embodiment, a second magnetic attracting block is provided on the outer wall of the cutting tooth where the hollow part is provided; a first magnetic attracting block is provided on the inner wall of the cutter blade outside the positioning through groove and is matched with the second magnetic attracting block. When energized, there is an attracting force between the first magnetic attracting block and the second magnetic attracting block. When the positioning column is embedded in the positioning card slot, the first magnetic attracting block is energized to ensure that the first magnetic attracting block and the second magnetic attracting block are adsorbed and connected together.

[0019] After the positioning column is embedded in the positioning card slot to realize the fixation of the cutting tooth, the adsorption effect of the first magnetic attracting block and the second magnetic attracting block can improve the fixation stability of the cutting tooth.

[0020] In a preferred embodiment, a first spring is provided on the inner wall of the cutter blade outside the positioning through groove; when the first magnetic attracting block and the second magnetic attracting block are adsorbed together, the first spring is compressed by the second magnetic attracting block, and the restoring force of the first spring is used to realize the disassembly of the cutting tooth.

[0021] Specifically, when the cutting tooth needs to be pulled out, the first magnetic attraction block and the second magnetic attraction block are powered off, and the magnetic attraction between them disappears. Under the restoring force of the first spring, the cutting tooth is moved out of the positioning through groove. That is, the restoring force of the first spring provided in the present invention can act as an external force when pulling out the cutting tooth.

[0022] In a preferred manner, the end of the positioning post away from the adjusting rod is an arc surface. The arc surface has a certain guiding effect, which is convenient for embedding the positioning post into the positioning card slot. And compared with a plane, during the process of moving the cutting tooth, the arc surface has a smaller frictional force with the inner wall of the positioning through groove, which is beneficial to moving the cutting tooth in the positioning through groove.

[0023] In a preferred manner, the replacement assembly includes a collection plate and a storage plate; the collection plate and the storage plate are arranged parallel to the side wall of the cutter wing provided with the positioning through groove, and the collection plate is placed between this side wall and the storage plate; A plurality of collection grooves are provided on the collection plate, and a third magnetic attraction block is provided at the bottom of the collection groove. The collection grooves correspond to the positioning through grooves one by one; A plurality of storage grooves are provided on the storage plate, and a fourth magnetic attraction block and a second spring are arranged in the storage groove. The new cutting tooth is fixed in the storage groove by the fourth magnetic attraction block. At this time, the second spring is compressed; the storage grooves correspond to the positioning through grooves one by one; The driving assembly includes a second telescopic member. One second telescopic member is connected to each of the collection plate and the storage plate, and the collection groove or the storage groove is moved to a position corresponding to the positioning through groove through the second telescopic member.

[0024] The replacement assembly provided in the present invention can realize the automatic replacement of the cutting tooth by operating the second telescopic member and cooperating with power on and off by itself.

[0025] In a preferred manner, a second magnetic attraction block is provided on the outer wall of the cutting tooth; when powered on, there is an attractive force between the second magnetic attraction block and the third magnetic attraction block; when powered on, there is an attractive force between the second magnetic attraction block and the fourth magnetic attraction block.

[0026] By providing the second magnetic attraction block, the third magnetic attraction block and the fourth magnetic attraction block, the present invention can utilize the magnetic attraction to realize the fixation of the cutting tooth and the recovery of the pulled-out cutting tooth. Moreover, by using the magnetic attraction between the third magnetic attraction block and the second magnetic attraction block, it can be used as an external force for pulling out the cutting tooth.

[0027] In a preferred manner, the storage plate includes a sliding plate and a fixing plate; The bottom of the sliding plate is slidably connected to the top of the fixing plate, and the storage grooves are provided on the sliding plate; A first telescopic member for pushing the sliding plate to move is provided in the installation cavity.

[0028] The present invention can set the width of the cutter blade to be relatively large, so that a collection plate, a storage plate and a first telescopic member can be installed in the installation cavity at the same time. The storage plate is set to include a sliding plate and a fixing plate. By lowering the collection plate, it is possible to avoid the collection plate blocking the displacement of the sliding plate, and then the first telescopic member is used to push the sliding plate to move close to the positioning through groove, reducing the distance between the storage plate and the positioning through groove, which is more conducive to pushing the cutting teeth stored in the storage plate into the positioning through groove.

[0029] In a preferred manner, one end of the second telescopic member is connected to the collection plate or the storage plate, and the other end is fixed in the cavity.

[0030] In a preferred manner, the replacement assembly includes a rotating storage plate; a plurality of fixing grooves are provided on the rotating storage plate, and new cutting teeth are fixedly arranged at intervals in the plurality of fixing grooves, and the fixing grooves without fixed cutting teeth are used for recycling old cutting teeth; All the positioning through grooves on the cutter blade are located on the same circumference, or at least a plurality of positioning through grooves are located on the same circumference; The driving assembly includes a rotating shaft and a power assembly, and the power assembly is used to drive the rotating shaft to rotate; the rotating storage plate is connected to the rotating shaft through a connecting plate, and the rotating shaft is located in the cavity and at the center of the circle corresponding to the circumference where the plurality of positioning through grooves are located.

[0031] The replacement assembly provided in the present invention realizes that by using a single rotating storage plate, it is possible to simultaneously collect old cutting teeth using empty fixing grooves, and push the new cutting teeth stored in the fixing grooves into the positioning through grooves for fixing, and the operation is simple. It only needs to rotate the rotating storage plate to respectively make the empty fixing grooves or the fixing grooves loaded with new cutting teeth correspond to the positioning through grooves one by one.

[0032] In a preferred manner, a sixth magnetic attraction block and a fourth spring are arranged in the fixing groove, and the new cutting teeth are fixed in the fixing groove through the sixth magnetic attraction block. At this time, the fourth spring is compressed.

[0033] The present invention can utilize the restoring force of the fourth spring to push the new cutting teeth into the fixing groove.

[0034] In a preferred manner, the cutter blade is installed on the outer wall of the drill bit body through bolts.

[0035] In a preferred manner, a communication groove for communicating the installation cavity and the cavity is provided on the outer wall of the drill bit body; a wing plate is provided on the outer wall of the drill bit body outside the communication groove, the cutter blade is connected to the wing plate through bolts, and an installation cavity is formed between the wing plate and the cutter blade.

[0036] Based on the above PDC drill bit replacement method, it includes the following steps: S1. Operate the driving assembly to make the storage unit correspond to the positioning through groove, and use the storage unit to pull out and collect the old cutting teeth in the positioning through groove; S2. Operate the driving component to return the storage unit to its original position, then operate the driving component to align the storage unit storing new cutting teeth with the positioning through groove. Push the new cutting teeth in the storage unit into the positioning through groove, and use the locking component to fix the cutting teeth in the positioning through groove.

[0037] Compared with the prior art, the present invention has the following advantages and beneficial effects: By improving the structure of the cutting teeth of the PDC bit, the present invention realizes automatic installation and disassembly under external force. Cooperating with the replacement component arranged in the installation cavity, it can automatically replace the cutting teeth of the PDC bit once during downhole operations, and further realize that the cutting teeth and other drilling tools are removed from the well for replacement at the same frequency, ultimately reducing the tripping frequency of drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings: Figure 1 is a schematic structural diagram of the PDC bit of the present invention; Figure 2 is a half-sectional view of the PDC bit of the present invention; Figure 3 is a schematic diagram of the collection plate installed in the blade in Embodiment 1 of the present invention; Figure 4 is a schematic diagram of the collection plate and the storage plate installed in the blade in Embodiment 1 of the present invention; Figure 5 is Figure 4 a partial enlarged view of A in Figure 6 is a schematic diagram of the cutting teeth installed on the side wall of the blade in Embodiment 1 of the present invention Figure 1 ; Figure 7 is a schematic diagram of the cutting teeth installed on the side wall of the blade in Embodiment 1 of the present invention Figure 2 ; Figure 8 is a schematic diagram of the storage plate in Embodiment 2 of the present invention Figure 1 ; Figure 9 is a schematic diagram of the storage plate in Embodiment 2 of the present invention Figure 2 ; Figure 10 is a schematic diagram of the rotary storage plate installed in the blade in Embodiment 3 of the present invention.

[0039] Reference numerals in the drawings and corresponding component names: 1 - Drill bit body; 2 - Connecting column; 3 - Blade; 4 - Cutting tooth; 5 - Collection plate; 6 - Storage plate; 7 - Rotating storage plate; 8 - First telescopic member; 9 - Locking assembly; 10 - Second telescopic member; 11 - Cavity; 12 - Wing plate; 31 - Positioning through groove; 32 - Positioning card slot; 33 - First magnetic block; 34 - First spring; 41 - Hollow part; 42 - Second magnetic block; 43 - Cover plate; 44 - Guide through groove; 45 - Fixed column; 51 - Collection groove; 52 - Third magnetic block; 61 - Storage groove; 62 - Fourth magnetic block; 63 - Second spring; 64 - Sliding plate; 65 - Fixed plate; 71 - Fixed groove; 72 - Connecting plate; 73 - Rotating shaft; 91 - Fixed sleeve; 92 - Third spring; 93 - Adjusting rod; 94 - Positioning column; 95 - Fifth magnetic block; 100 - Bolt; 121 - Through hole. Detailed implementation mode

[0040] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with embodiments. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and do not limit the present invention. The following described embodiments are part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0041] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that: it is not necessary to adopt these specific details to implement the present invention. In other embodiments, well-known structures, materials or methods are not specifically described in order to avoid obscuring the present invention. The materials, instruments and reagents used in the following embodiments can be obtained from commercial sources without special instructions. The technical means used in the embodiments are conventional means well-known to those skilled in the art without special instructions.

[0042] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0043] Embodiment 1: In order to reduce the frequency of tripping in the drilling engineering, such as Figures 1 - 7As shown in the figure, a PDC bit with automatic downhole tooth replacement includes a bit body 1. One end of the bit body 1 is provided with a connecting column 2, which is connected to the drill pipe through the connecting column 2. A plurality of cutter wings 3 are arranged on the outer wall of the bit body 1. One end of the cutter wing 3 is placed at the top of the bit body 1, and the other end extends to the outer wall of the bit body 1. The overall shape of the bit body 1 is cylindrical, and the top of the bit body 1 is an arc surface, forming a cavity 11 inside the bit body 1 for installing other components. A plurality of cutting teeth 4 are arranged on the cutter wing 3. As Figure 1 shown, a plurality of cutting teeth 4 are arranged in rows. In this embodiment, in order to realize the automatic downhole replacement of the cutting teeth 4, the structure of the cutter wing 3 is improved in this embodiment. An installation cavity is arranged inside the cutter wing 3 of this embodiment, and the installation cavity communicates with the cavity 11 inside the bit body 1. That is, the inside of the cutter wing 3 of this embodiment is a hollow structure, and this hollow structure can be used to recover the old or to-be-replaced cutting teeth 4 and store the new cutting teeth 4.

[0044] In this embodiment, the cutter wing 3 is installed on the outer wall of the bit body 1 through bolts 100. Specifically, a communication groove for communicating the installation cavity and the cavity 11 is arranged on the outer wall of the bit body 1. A wing plate 12 is arranged on the outer wall of the bit body 1 outside the communication groove. A through hole 121 for passing through the bolt 100 is arranged on the wing plate 12. The cutter wing 3 is connected to the wing plate 12 through the bolt 100, and an installation cavity is formed between the wing plate 12 and the cutter wing 3.

[0045] In order to realize the automatic downhole replacement of the cutting teeth 4, a plurality of positioning through grooves 31 are arranged on the side wall of the cutter wing 3 of this embodiment, and the inside and outside of the cutter wing 3 are communicated through the positioning through grooves 31. The positioning through grooves 31 correspond to the cutting teeth 4 one by one, that is, one cutting tooth 4 is detachably installed in each positioning through groove 31. A positioning card slot 32 is arranged on the inner wall of the positioning through groove 31. The number of positioning card slots 32 arranged on the inner wall of each positioning through groove 31 can be 1, 2, 3, etc. As Figure 6 、 Figure 7 shown, two positioning card slots 32 are symmetrically arranged on the inner wall of the positioning through groove 31.

[0046] The cutting tooth 4 is detachably fixed in the positioning through groove 31 through the locking assembly 9 and external force. The locking assembly 9 includes a positioning column 94, and the locking assembly 9 can make the positioning column 94 embed or move out of the positioning card slot 32. The working principle of specifically realizing the locking and removal of the cutting tooth 4 in this embodiment is: When the cutting tooth 4 needs to be installed, the cutting tooth 4 is inserted into the positioning through groove 31 from one side of the installation cavity by an external force, and the cutting tooth 4 is pushed forward in the positioning through groove 31 by the external force. Before the positioning post 94 reaches the position corresponding to the positioning card slot 32, the positioning post 94 is restricted by the inner wall of the positioning through groove 31. When the positioning post 94 reaches the position corresponding to the positioning card slot 32, the restriction of the inner wall of the positioning through groove 31 is lost, and the positioning post 94 radially moves into the positioning card slot 32 to realize the installation and fixation of the cutting tooth 4. At this time, one end of the cutting tooth 4 protrudes from the positioning through groove 31 and bites into the rock and soil during the drilling process of the PDC bit. In an alternative embodiment, as Figures 6 - 7 shown, the outer diameter of the cutting tooth 4 is the same as the inner diameter of the positioning through groove 31.

[0047] When the cutting tooth 4 needs to be recycled, an external force opposite to that during installation is applied, and the cutting tooth 4 is pulled out and recycled by the external force.

[0048] Therefore, in order to facilitate the movement of the cutting tooth 4 in the positioning through groove 31 during installation and recycling, the end of the positioning post 94 in contact with the inner wall of the positioning through groove 31 can be set as an arc surface, and then the structure of the positioning card slot 32 can be adaptively designed based on the specific structure of the positioning post 94. In an alternative embodiment, as Figures 6 - 7 shown, the whole of the positioning post 94 is in a column shape, and one end of the column is an arc surface. The positioning card slot 32 is a conical cavity, and the cross section is triangular.

[0049] The external force adopted in this embodiment can be any structure that can realize the two-way movement of the cutting tooth 4. For example: magnetic adsorption forces in different directions, telescopic structures, etc. Among them, the magnetic adsorption force is realized by the on-off method between two magnetic attraction blocks. When powered on, there is an attractive force between the two magnetic attraction blocks. When one of the magnetic attraction blocks is fixed, the other is pulled close by the attractive force, realizing the movement of the other magnetic attraction block driving the component fixed thereto. Making the two magnetic attraction blocks attract each other when powered on is a prior art, using the magnetic field generated by the magnet when powered on to adsorb metal. That is, in specific implementation, the fixed magnetic attraction block can be set as a magnet, and the moving magnetic attraction block can be set as a metal block that can be adsorbed and moved; when powered off, the attractive force between the two magnetic attraction blocks is lost, and the other magnetic attraction block can be returned by the restoring force of other elastic components; the telescopic structure can specifically be a hydraulic cylinder.

[0050] In this embodiment, a specific structure for realizing the movement of the cutting tooth 4 is: one end of the cutting tooth 4 is a solid part, and a hollow part 41 is arranged at the other end; after the cutting tooth 4 is installed in the positioning through groove 31, all or part of the solid part of the cutting tooth 4 protrudes from the positioning through groove 31.

[0051] Among them, the locking assembly 9 is installed in the hollow part 41. The locking assembly 9 includes two adjusting rods 93. One end of the adjusting rod 93 is hinged in the hollow part 41, and the other end is connected to the positioning post 94. Preferably, the end of the positioning post 94 away from the adjusting rod 93 is an arc surface. The two adjusting rods 93 are connected by a third spring 92. When the positioning post 94 is restricted by the inner wall of the positioning through groove 31, the distance between the two positioning posts 94 is relatively small. At this time, the third spring 92 is in a compressed state. When the positioning post 94 moves to a position corresponding to the positioning card slot 32, the positioning post 94 is pushed into the positioning card slot 32 under the restoring action of the third spring 92, realizing the fixation of the cutting tooth 4. A guiding through groove 44 for passing through the positioning post 94 is provided on the side wall of the hollow part 41. To facilitate the hinging of the adjusting rod 93, a fixing post 45 is provided in the hollow part 41. The locking assembly 9 further includes a fixing sleeve 91. The fixing sleeve 91 is fixed to the outer wall of the fixing post 45, and a hinging part is provided on the fixing sleeve 91 for realizing the hinging with one end of the adjusting rod 93. The hinging part can specifically be a shaft, and one end of the adjusting rod 93 is rotatably arranged on the shaft. The opening and closing between the two adjusting rods 93 is realized by the rotation of one end of the adjusting rod 93. Preferably, to facilitate the installation of the locking assembly 9, one end of the hollow part 41 is set as an open end, and a detachable cover plate 43 is provided at the opening end.

[0052] In a preferred case, in order to quickly and smoothly remove the cutting tooth 4 from the positioning through groove 31 when recycling the cutting tooth 4; a fifth magnetic attraction block 95 is provided at the other end of the adjusting rod 93. When powered on, there is an attracting force between the two fifth magnetic attraction blocks 95. When it is necessary to recycle the cutting tooth 4, the fifth magnetic attraction blocks 95 are powered on, and the two fifth magnetic attraction blocks 95 attract and approach each other, so that the positioning post 94 is removed from the positioning card slot 32, facilitating the application of an external force to pull out the cutting tooth 4 from the positioning through groove 31.

[0053] In a preferred case, in order to achieve better stability after the cutting tooth 4 is installed in the positioning through groove 31, a second magnetic attraction block 42 is provided on the outer wall of the cutting tooth 4 provided with the hollow part 41; a first magnetic attraction block 33 cooperating with the second magnetic attraction block 42 is provided on the inner wall of the cutter wing 3 outside the positioning through groove 31. When powered on, there is an attracting force between the first magnetic attraction block 33 and the second magnetic attraction block 42. When the positioning post 94 is embedded in the positioning card slot 32, the first magnetic attraction block 33 and the second magnetic attraction block 42 are adsorbed and connected together. Specifically, the first magnetic attraction block 33 is a fixed structure and can be a magnet, while the second magnetic attraction block 42 that moves with the cutting tooth 4 can be a metal such as iron that can be adsorbed and moved by a magnet. In this embodiment, the adsorption effect of the first magnetic attraction block 33 and the second magnetic attraction block 42 can be used to improve the fixing stability of the cutting tooth 4 during the drilling process.

[0054] In a preferred case, in order to facilitate the extraction of the cutting tooth 4 during recycling, a first spring 34 is provided on the inner wall of the cutter wing 3 outside the positioning through groove 31. When the first magnetic attraction block 33 and the second magnetic attraction block 42 are attracted to each other, the first spring 34 is compressed by the second magnetic attraction block 42. When it is necessary to extract the cutting tooth 4, the first magnetic attraction block 33 and the second magnetic attraction block 42 are powered off and lose the attraction force, and the cutting tooth 4 is pushed out of the positioning through groove 31 under the restoring force of the first spring 34.

[0055] A replacement assembly is provided in the installation cavity. The replacement assembly includes a storage unit for collecting the old cutting teeth 4, a storage unit storing new cutting teeth 4, and a driving assembly for driving the old cutting teeth 4 into the storage unit and fixing the new cutting teeth 4 in the positioning card slots 32. In this embodiment, the above-mentioned one-time automatic replacement of the detachable cutting teeth 4 can be installed by using the replacement assembly.

[0056] Specifically, the replacement assembly includes a collection plate 5 and a storage plate 6. The collection plate 5 and the storage plate 6 are arranged parallel to the side wall of the cutter wing 3 provided with the positioning through groove 31, and the collection plate 5 is disposed between this side wall and the storage plate 6.

[0057] Among them, a plurality of collection grooves 51 are provided on the collection plate 5. A third magnetic attraction block 52 is provided at the bottom of the collection groove 51. The collection grooves 51 correspond to the positioning through grooves 31 one by one. At this time, a second magnetic attraction block 42 is provided on the outer wall of the cutting tooth 4 provided with the hollow part 41, or a magnetic attraction block is provided on the cover plate 43 of the cutting tooth 4. When powered on, there is a magnetic adsorption force between the third magnetic attraction block 52 and the end of the cutting tooth 4. The cutting tooth 4 is adsorbed into the collection groove 51 for fixation by using the magnetic adsorption force. Specifically, the third magnetic attraction block 52 can be a magnet, and the cover plate 43 or the second magnetic attraction block 42 is a metal such as iron that can be attracted and moved by the magnet.

[0058] Among them, a plurality of storage slots 61 are provided on the storage plate 6. A fourth magnetic attraction block 62 and a second spring 63 are arranged in the storage slot 61. The new cutting tooth 4 is fixed in the storage slot 61 through the fourth magnetic attraction block 62. At this time, the second spring 63 is compressed; the storage slots 61 correspond to the positioning through slots 31 one by one. Specifically, the fourth magnetic attraction block 62 is arranged on the inner wall of the storage slot 61, and the fourth magnetic attraction block 62 is an annular magnetic attraction block, and a central through hole capable of passing through the second spring 63 is provided in the middle thereof. One end of the second spring 63 is fixed to the bottom of the storage slot 61, and the other end passes through the central through hole. A second magnetic attraction block 42 is arranged on the outer wall of the hollow part 41 of the cutting tooth 4. The cutting tooth 4 is fixed in the storage slot 61 by the magnetic attraction between the second magnetic attraction block 42 and the fourth magnetic attraction block 62. Specifically, the fourth magnetic attraction block 62 is a magnet that can generate magnetic attraction force when energized, and the second magnetic attraction block 42 is a metal such as iron that can be adsorbed and moved by the magnet. When it is necessary to replace the cutting tooth 4, after the old cutting tooth 4 has been pulled out of the positioning through slot 31, the fourth magnetic attraction block 62 is powered off, and the magnetic attraction between the fourth magnetic attraction block 62 and the second magnetic attraction block 42 is lost. Under the restoring force of the second spring 63, the cutting tooth 4 stored in the storage slot 61 is pushed into the corresponding positioning through slot 31.

[0059] The driving assembly includes a second telescopic member 10. One second telescopic member 10 is connected to each of the collecting plate 5 and the storage plate 6. One end of the second telescopic member 10 is connected to the collecting plate 5 or the storage plate 6, and the other end is fixed in the cavity 11; the collecting plate 5 or the storage plate 6 is moved by the telescopic movement of the second telescopic member 10, so as to move the collecting slot 51 or the storage slot 61 to a position corresponding to the positioning through slot 31. Specifically, in this embodiment, all the positioning through slots 31 on the cutter blade 3 are located on the same circumference, or at least multiple positioning through slots 31 are located on the same circumference. In a specific case, as Figure 3 shown, nine positioning through slots 31 are sequentially arranged on each cutter blade 3 from top to bottom. Among them, the first seven positioning through slots 31 are located on a 1 / 4 circular arc of the same circumference, and the remaining two positioning through slots 31 are located on the tangent line of the circumference and are vertically arranged. In this embodiment, the cutting teeth 4 in the seven positioning through slots 31 located on a 1 / 4 circular arc of the same circumference can be replaced. Since most of the cutting teeth 4 have been replaced by replacing the cutting teeth 4 in the seven positioning through slots 31, and the remaining two are not replaced, it has little impact on the use of the PDC bit and can be replaced manually together after the well is drilled. In actual use, all the positioning through slots 31 can be arranged on the same circumference to realize the replacement of all the cutting teeth 4. The circumferences where the collecting slots 51 on the collecting plate 5 and the storage slots 61 on the storage plate 6 are located are always concentric with the circumference where the positioning through slots 31 are located, and the telescopic direction of the second telescopic member 10 is the radial direction of the circumference where the collecting slot 51 or the storage slot 61 is located, and is located in the middle of the 1 / 4 circular arc where the positioning through slots 31 are located. The moving path of the second telescopic member 10 is as Figure 3as shown by the dashed line therein. The second telescopic member 10 may specifically be a hydraulic cylinder.

[0060] Based on the above PDC bit replacement method, it includes the following steps: S1. Operate the driving assembly to make the storage unit correspond to the positioning through groove 31, and use the storage unit to pull out and collect the old cutting teeth 4 in the positioning through groove 31; S2. Operate the driving assembly to retract the storage unit, and then operate the driving assembly to make the storage unit storing the new cutting teeth 4 correspond to the positioning through groove 31, use the storage unit to push the new cutting teeth 4 therein into the positioning through groove 31, and use the locking assembly 9 to fix the cutting teeth 4 in the positioning through groove 31.

[0061] Specifically, the working principle of this embodiment is as follows: A. When it is necessary to replace the old cutting teeth 4, operate the second telescopic member 10 to extend, and move the collection groove 51 on the collection plate 5 along the Figure 3 dashed line shown to a position corresponding to the positioning through groove 31, that is, the same height. Here, the height is relative to the Figure 3 dashed line shown. Then, the first magnetic attraction block 33 is powered off, so that the magnetic adsorption force between the first magnetic attraction block 33 and the second magnetic attraction block 42 is lost. Under the restoring force of the first spring 34, the cutting teeth 4 are pushed out of the positioning through groove 31. Then, the third magnetic attraction block 52 is powered on, and the third magnetic attraction block 52 adsorbs the second magnetic attraction block 42 and / or the cover plate 43 to adsorb the old cutting teeth 4 into the collection groove 51 for fixation.

[0062] B. Then operate the second telescopic member 10 to retract, and move the collection plate 5 along the Figure 3 dashed line shown to a position lower than the positioning through groove 31, so that the collection plate 5 does not block the new cutting teeth 4 in the storage plate 6 from being pushed into the positioning through groove 31.

[0063] C. Operate the second telescopic member 10 to extend, and move the storage groove 61 in the storage plate 6 along the Figure 3 dashed line shown to a position corresponding to the positioning through groove 31, that is, the same height; then the fourth magnetic attraction block 62 is powered off, the magnetic adsorption force between the fourth magnetic attraction block 62 and the second magnetic attraction block 42 is lost, and under the restoring force of the second spring 63, the cutting teeth 4 stored in the storage groove 61 are pushed into the corresponding positioning through groove 31.

[0064] D. When the cutting teeth 4 enter the positioning through groove, the first magnetic attraction block 33 is powered on, and the magnetic adsorption force between the first magnetic attraction block 33 and the second magnetic attraction block 42 is used to ensure that the cutting teeth 4 advance until the positioning post 94 is embedded in the positioning card slot 32.

[0065] That is, in this embodiment, the magnetic adsorption force is used to provide the external force for the movement of the cutting teeth 4.

[0066] Embodiment 2: As Figures 1 - 9 shown, in this embodiment, in order to shorten the distance for the new cutting tooth 4 to be pushed into the positioning through groove 31, the storage plate 6 is arranged to include a sliding plate 64 and a fixing plate 65; The bottom of the sliding plate 64 is slidably connected to the top of the fixing plate 65, and any existing solid sliding connection can be used, such as the way of a slider cooperating with a slide rail. The storage groove 61 is arranged on the sliding plate 64; A first telescopic member 8 for pushing the sliding plate 64 to move is arranged in the installation cavity.

[0067] The working principle of this example is as follows: When the storage groove 61 is moved to a position corresponding to the positioning through groove 31 through the second telescopic member 10, then the first telescopic member 8 is extended, so that the sliding plate 64 moves close to the positioning through groove 31 until the sliding plate 64 moves above the collecting plate 5, making the distance between the storage groove 61 and the positioning through groove 31 closer, and then the cutting tooth 4 is pushed into the positioning through groove 31.

[0068] Embodiment 3: As Figure 1 、 Figure 2 、 Figure 6 、 Figure 7 and 10 shown: The difference between this embodiment and Embodiment 1 is that the structures of the replacement components are different.

[0069] In this embodiment, the replacement component includes a rotary storage plate 7; a plurality of fixing grooves 71 are arranged on the rotary storage plate 7, and a plurality of new cutting teeth 4 are fixedly arranged at intervals in the plurality of fixing grooves 71. The fixing grooves 71 without fixed cutting teeth 4 are used for recycling the old cutting teeth 4; for example: when there are 7 positioning through grooves 31 arranged on the cutter wing 3, 14 fixing grooves 71 are arranged on the rotary storage plate 7, numbered 1# - 14# respectively. Among them, the odd-numbered fixing grooves 71 are empty, and the even-numbered fixing grooves 71 are fixed with new cutting teeth 4.

[0070] In this embodiment, in order to realize that the odd-numbered or even-numbered fixing grooves 71 correspond to the positioning through grooves 31 by rotation, all the positioning through grooves 31 on the cutter wing 3 of this example are located on the same circumference, or at least multiple positioning through grooves 31 are located on the same circumference; when all the positioning through grooves 31 are all located on the same circumference, all the cutting teeth 4 can be replaced. When some of the cutting teeth 4 are located on the same circumference, multiple cutting teeth 4 located on the same circumference can be replaced. During actual use, the arrangement of the cutting teeth 4 can be set according to the wear degree of the cutting teeth 4 at different positions during drilling, whether they are all located on the same circumference or only part of them.

[0071] The driving component of this embodiment includes a rotating shaft 73 and a power component, and the power component is used to drive the rotating shaft 73 to rotate; the rotating storage plate 7 is connected to the rotating shaft 73 through a connecting plate 72. The rotating shaft 73 is located in the cavity 11 and at the center of the circle corresponding to the circumference where multiple positioning through slots 31 are located. That is, the rotation path of the rotating storage plate 7 in this embodiment is as shown by the dashed line in Figure 10 . Specifically, the power component includes a motor and a gear transmission mechanism. The gear transmission mechanism includes a driving wheel and a driven wheel that mesh with each other. Among them, the driving wheel is connected to the power output shaft of the motor, and the driven wheel is connected to the rotating shaft 73. When the motor rotates forward, the rotating storage plate 7 is driven to rotate counterclockwise by a certain angle through the gear transmission mechanism. When the motor rotates in reverse, the rotating storage plate 7 returns to its original position.

[0072] In the fixed slot 71 of this embodiment, a sixth magnetic attraction block and a fourth spring are provided. The new cutting tooth 4 is fixed in the fixed slot 71 through the sixth magnetic attraction block. At this time, the fourth spring is compressed. That is, the structure and working principle of the fixed slot 71 in this embodiment are the same as those of the storage slot 61 in Embodiment 1.

[0073] The working principle of this embodiment is as follows: A. In the initial state, the empty fixed slots 71 on the rotating storage plate 7 are at the same height as and correspond one by one to the positioning through slots 31. When it is necessary to replace the old cutting teeth 4, the old cutting teeth 4 in the positioning through slots 31 are pushed into the empty fixed slots 71, and the adsorption effect between the sixth magnetic attraction block and the second magnetic attraction block 42 is utilized to fix the old cutting teeth 4.

[0074] B. The driving motor drives the rotating storage plate 7 by a certain angle so that the fixed slots 71 on the rotating storage plate 7 loaded with new cutting teeth 4 are at the same height as and correspond one by one to the positioning through slots 31. Then, the sixth magnetic attraction block in the fixed slot 71 is powered off, and the restoring force of the fourth spring is utilized to push the new cutting teeth 4 into the corresponding positioning through slots 31.

[0075] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0076] It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of clear description and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

Claims

1. A PDC bit with automatic downhole tooth replacement, comprising a bit body (1), wherein a plurality of cutter wings (3) are arranged on the outer wall of the bit body (1), and cutting teeth (4) are arranged on the cutter wings (3); characterized in that, An installation cavity is provided inside the cutter blade (3); A plurality of positioning through slots (31) are provided on the side wall of the cutter blade (3), the positioning through slots (31) correspond to the cutting teeth (4) one by one, and a positioning clamping slot (32) is provided on the inner wall of the positioning through slots (31); The cutting tooth (4) is detachably fixed in the positioning through slot (31) by a locking assembly (9) in cooperation with an external force; the locking assembly (9) includes a positioning post (94), and the locking assembly (9) can make the positioning post (94) embed or move out of the positioning clamping slot (32); A replacement assembly is provided in the installation cavity, and the replacement assembly includes a storage unit for collecting the old cutting teeth (4), a storage unit storing new cutting teeth (4), and a driving assembly for driving the old cutting teeth (4) into the storage unit and fixing the new cutting teeth (4) in the positioning clamping slot (32).

2. The PDC bit with automatic downhole tooth replacement according to claim 1, characterized in that, One end of the cutting tooth (4) is a solid part, and a hollow part (41) is provided inside the other end; The locking assembly (9) is installed inside the hollow part (41), the locking assembly (9) includes two adjusting rods (93), one end of the adjusting rod (93) is hinged inside the hollow part (41), the other end is connected to the positioning post (94), and the two adjusting rods (93) are connected by a third spring (92); A guiding through slot (44) for passing through the positioning post (94) is provided on the side wall of the hollow part (41).

3. The PDC bit for automatically replacing teeth underground according to claim 2, wherein, The other end of the adjusting rod (93) is provided with a fifth magnetic attraction block (95), and when powered on, there is an attractive force between the two fifth magnetic attraction blocks (95).

4. The PDC bit with automatic downhole tooth replacement according to claim 2, wherein, A second magnetic attraction block (42) is provided on the outer wall of the cutting tooth (4) where the hollow part (41) is provided; a first magnetic attraction block (33) matching the second magnetic attraction block (42) is provided on the inner wall of the cutter blade (3) outside the positioning through slot (31). When the positioning post (94) is embedded in the positioning clamping slot (32), the first magnetic attraction block (33) is powered on to ensure that the first magnetic attraction block (33) and the second magnetic attraction block (42) are adsorbed and connected together.

5. The PDC bit with automatic downhole tooth replacement according to claim 4, characterized in that, A first spring (34) is provided on the inner wall of the cutter blade (3) outside the positioning through slot (31); the restoring force of the first spring (34) is used to realize the disassembly of the cutting tooth (4).

6. The PDC bit with automatic downhole tooth replacement according to claim 2, wherein, The end of the positioning post (94) away from the adjusting rod (93) is an arc surface.

7. The PDC bit with automatic downhole tooth replacement according to claim 1, characterized in that, The replacement assembly includes a collecting plate (5) and a storage plate (6); the collecting plate (5) and the storage plate (6) are arranged parallel to the side wall of the cutter blade (3) where the positioning through slots (31) are provided, and the collecting plate (5) is placed between this side wall and the storage plate (6); A plurality of collecting grooves (51) are provided on the collecting plate (5), a third magnetic attraction block (52) is provided at the bottom of the collecting grooves (51), and the collecting grooves (51) correspond to the positioning through slots (31) one by one; A plurality of storage slots (61) are provided on the storage plate (6). A fourth magnetic attraction block (62) and a second spring (63) are arranged in the storage slot (61). A new cutting tooth (4) is fixed in the storage slot (61) through the fourth magnetic attraction block (62). At this time, the second spring (63) is in a compressed state. The storage slots (61) correspond to the positioning through slots (31) one by one. The driving assembly includes a second telescopic member (10). One second telescopic member (10) is connected to each of the collection plate (5) and the storage plate (6). The collection slot (51) or the storage slot (61) is moved to a position corresponding to the positioning through slot (31) through the second telescopic member (10).

8. An underground automatic tooth-changing PDC bit according to claim 7, characterized in that, A second magnetic attraction block (42) is arranged on the outer wall of the cutting tooth (4). When powered on, there is an attractive force between the second magnetic attraction block (42) and the third magnetic attraction block (52). There is an attractive force between the second magnetic attraction block (42) and the fourth magnetic attraction block (62).

9. The PDC bit with automatic downhole tooth replacement according to claim 7, characterized in that, The storage plate (6) includes a sliding plate (64) and a fixed plate (65). The bottom of the sliding plate (64) is slidably connected to the top of the fixed plate (65). The storage slots (61) are arranged on the sliding plate (64). A first telescopic member (8) for pushing the sliding plate (64) to move is arranged in the installation cavity.

10. A PDC bit with automatic downhole tooth replacement according to claim 7, characterized in that, One end of the second telescopic member (10) is connected to the collection plate (5) or the storage plate (6), and the other end is fixed in a cavity (11) inside the drill bit body (1).

11. The PDC bit with automatic downhole tooth replacement according to claim 1, characterized in that, The replacement assembly includes a rotary storage plate (7). A plurality of fixing slots (71) are provided on the rotary storage plate (7). A plurality of new cutting teeth (4) are fixedly arranged at intervals in the fixing slots (71). The fixing slots (71) without the fixed cutting teeth (4) are used for recycling the old cutting teeth (4). All the positioning through slots (31) on the cutter blade (3) are located on the same circumference, or at least a plurality of the positioning through slots (31) are located on the same circumference. The driving assembly includes a rotating shaft (73) and a power assembly. The power assembly is used to drive the rotating shaft (73) to rotate. The rotary storage plate (7) is connected to the rotating shaft (73) through a connecting plate (72). The rotating shaft (73) is located in the cavity (11) inside the drill bit body (1) and at the center of the circle corresponding to the circumference where a plurality of positioning through slots (31) are located.

12. The PDC bit with automatic downhole tooth replacement according to claim 11, characterized in that, A sixth magnetic attraction block and a fourth spring are arranged in the fixing slot (71). A new cutting tooth (4) is fixed in the fixing slot (71) through the sixth magnetic attraction block. At this time, the fourth spring is compressed.

13. A PDC bit with automatic downhole tooth replacement according to any one of claims 1-12, characterized in that, The cutter blade (3) is installed on the outer wall of the drill bit body (1) through bolts (100).

14. A PDC bit for automatically replacing teeth underground according to claim 13, characterized in that, A communication groove for communicating the installation cavity and a cavity (11) inside the drill bit body (1) is provided on the outer wall of the drill bit body (1); a wing plate (12) is provided on the outer wall of the drill bit body (1) outside the communication groove, the cutter wing (3) is connected to the wing plate (12) by a bolt (100), and the installation cavity is formed between the wing plate (12) and the cutter wing (3).

15. The replacement method of the PDC bit according to any one of claims 1-14, characterized in that, It includes the following steps: S1. Operate the driving component to make the receiving unit correspond to the positioning through groove (31), and use the receiving unit to pull out and collect the old cutting teeth (4) in the positioning through groove (31); S2. Operate the driving component to return the receiving unit, then operate the driving component to make the storage unit storing new cutting teeth (4) correspond to the positioning through groove (31), use the storage unit to push the new cutting teeth (4) therein into the positioning through groove (31), and use the locking component (9) to fix the cutting teeth (4) in the positioning through groove (31).

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