Two-stage drilling reamer

Abstract

This disclosure relates to the field of drilling tool technology and provides a two-stage reamer, comprising a housing, a shift shaft, a primary rock-breaking blade, and a secondary rock-breaking blade. The housing has an internal through-cavity. The shift shaft movably passes through the through-cavity. The primary rock-breaking blade is movably inserted into the housing wall, having a rock-breaking side extending out of the housing and an abutting side located in the through-cavity. The secondary rock-breaking blade is spaced above the primary rock-breaking blade and movably inserted into the housing wall, also having a rock-breaking side extending out of the housing and an abutting side located in the through-cavity. Under external force, the shift shaft can descend vertically to the trigger position, simultaneously abutting the abutting sides of both the primary and secondary rock-breaking blades, allowing their rock-breaking sides to extend out of the housing at different lengths. This two-stage reamer effectively solves the problem of frequent tripping and reamer replacement during multi-stage reaming operations, improving drilling reaming efficiency.

Description

Technical Field

[0001] This disclosure relates to the field of drilling tools technology, and in particular to a two-stage drilling reamer. Background Technology

[0002] The oil and gas well drilling industry is gradually shifting towards complex working conditions such as deep wells, ultra-deep wells, and geothermal wells. As drilling depth continues to increase, drill bit size decreases accordingly, and wellbore size cannot meet the needs of drilling and subsequent work. Therefore, it is necessary to use enlargement technology to enlarge the diameter of small wellbores such as deep wells and ultra-deep wells.

[0003] Traditional reamers are mostly ball-throwing pressure-pressurizing post-drilling reamers. They use the ball-throwing pressure-pressurizing shear pin method to change the pressure differential action surface, triggering the reamer blades to unfold. The blades are inlaid with cutting teeth. After the blades unfold, the cutting teeth press into the well wall and grind, shear and break the rock along with the rotation of the drill pipe, thereby achieving wellbore enlargement.

[0004] However, traditional reamers cannot adjust the blade extension stroke in real time according to the complex downhole conditions. They cannot be drilled in one trip for different reaming needs, and often need to be pulled out and replaced with different models of reamers, which increases drilling time and indirectly increases drilling costs. Summary of the Invention

[0005] This disclosure provides a two-stage reamer, which addresses the problem in related technologies that reamers cannot flexibly adjust the blade deployment stroke and cannot achieve single-pass reaming of different sizes.

[0006] The dual-stage drilling reamer provided in this embodiment includes a housing, a shift shaft, a first-stage rock-breaking blade, and a second-stage rock-breaking blade; The interior of the shell has a through cavity along the vertical direction; The shift shaft is movably inserted through the through cavity; The first-stage rock-breaking blade is movably inserted into the shell wall of the shell, and has a rock-breaking side that can extend out of the shell and an abutting side located in the through cavity; The secondary rock-breaking blades are spaced above the primary rock-breaking blades and are movably inserted into the shell wall of the housing. They have a rock-breaking side that can extend out of the housing and an abutting side located in the through cavity. The shift shaft can descend vertically to the trigger position in the through cavity under the action of external force, and simultaneously push against the contact side of the first-stage rock-breaking blade and the second-stage rock-breaking blade, so that the rock-breaking side of the two can extend out of the shell at different lengths.

[0007] In one embodiment, the shift shaft includes a first shaft segment and a second shaft segment that are fixedly connected. The first shaft segment has a first radial dimension and is capable of abutting the contact side of the first-stage rock-breaking blade along its own radial direction; The second shaft segment has a second radial dimension and is able to abut against the contact side of the secondary rock-breaking blade along its own radial direction; When the first shaft segment moves downward in the through cavity, the first shaft segment can push the first-stage rock-breaking blade out of the shell at different lengths. As the second shaft segment descends and moves within the through cavity, it can push the secondary rock-breaking blades out of the housing at different lengths.

[0008] In one embodiment, multiple primary rock-breaking blades and secondary rock-breaking blades are arranged in a circular array around the central axis of the shell; The contact sides of multiple primary rock-breaking blades together form a first stepped hole with varying diameter; The contact sides of multiple secondary rock-breaking blades together form a second stepped hole with varying diameter; When the first shaft segment is inserted into the upper section of the first stepped hole, the second shaft segment is simultaneously inserted into the upper section of the second stepped hole, and the first-stage rock-breaking blade and the second-stage rock-breaking blade extend out of the shell at the first length. When the first shaft segment is inserted into the lower section of the first stepped hole, the second shaft segment is simultaneously inserted into the lower section of the second stepped hole, and the first-stage rock-breaking blade and the second-stage rock-breaking blade extend out of the housing at the second length. In one embodiment, the housing is fixedly provided with a stop pin in its own shell wall; The shift shaft has a shift shaft section, and a shift groove is provided in the outer peripheral wall of the shift shaft section for the fixed pin to be inserted and fitted. When the shift shaft moves vertically to different trigger positions in the through cavity, the fixed pin is correspondingly limited and blocked at different gear levels in the shift groove.

[0009] In one possible embodiment, the shifting groove includes a tortuous groove, a reset groove, a first gear groove, and a second gear groove; The tortuous groove is sawtooth-shaped and surrounds the outer peripheral wall of the shift shaft section; The reset channel is straight and is vertically connected to the lower corner of the tortuous channel; The first gear groove is straight and is vertically connected to the upper corner of the tortuous groove. The second gear groove is straight and is vertically connected to the upper corner of the tortuous groove; The first gear slot and the second gear slot are arranged alternately and interleaved, and the length of the first gear slot is less than the length of the second gear slot.

[0010] In one possible implementation, the dual-stage reamer further includes a cutter blade return spring; The blade return spring is connected and disposed between the housing and the first-stage rock-breaking blade, and between the housing and the second-stage rock-breaking blade, for applying a spring force to the first-stage rock-breaking blade and the second-stage rock-breaking blade toward the housing to return to its original position.

[0011] In one possible embodiment, the two-stage reamer further includes a mandrel return spring; The spindle return spring is connected between the housing and the shift shaft, and is used to apply an upward return force to the shift shaft.

[0012] In one possible implementation, a cutting wheel is provided in the primary rock-breaking blade; The cutting wheel is rotatably mounted on the first-stage rock-breaking blade via a self-renewing shaft; During the process of the first-stage rock-breaking blade extending out of the housing, the self-renewing shaft can drive the cutting wheel to rotate unidirectionally by a certain angle.

[0013] In one possible embodiment, an opening is provided in the housing for the extension and retraction of the first-stage rock-breaking blade, and a pawl and a self-locking block are correspondingly provided in the opening; The self-renewing shaft includes a ratchet section, a key section, and a self-locking section that are coaxially connected in sequence. When the first-stage rock-breaking blade drives the cutting wheel to extend out of the opening, the pawl and the ratchet part cooperate to form a check ratchet mechanism, which drives the self-renewing shaft and the cutting wheel to rotate in one direction by a certain angle, and causes the self-locking part to abut and lock against the self-locking block.

[0014] In one embodiment, polycrystalline diamond cutting teeth are provided on the rock-breaking side of the secondary rock-breaking blade.

[0015] The technical solution provided in this disclosure has the following advantages compared with related technologies: The dual-stage reamer provided in this embodiment allows for flexible borehole enlargement of different sizes during a single drilling run by changing the specific abutment position of the shift shaft, enabling the primary and secondary rock-breaking blades to extend to different lengths. Furthermore, the sequential enlargement method using the primary and secondary rock-breaking blades effectively solves the problem of frequent tripping and reamer replacement during multi-stage enlargement operations, improving drilling efficiency and saving costs associated with changing reamers of different sizes. Moreover, the sequential enlargement and rock breaking by the primary and secondary rock-breaking blades not only achieves efficient rock breaking and enlargement but also effectively copes with complex formation environments during drilling, avoiding rapid tool wear caused by a single rock-breaking method and extending the service life of the dual-stage reamer.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0017] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0018] Figure 1 A vertical cross-sectional view of the two-stage drilling reamer provided in this disclosure is shown; Figure 2 A schematic diagram of the two-stage drilling reamer provided in this disclosure in the reset state is shown, wherein... Figure 2 (a) is a three-dimensional view of the reset state. Figure 2 (b) is a half-section view of the reset state; Figure 3 A schematic diagram of the two-stage reamer provided in this disclosure in its first position is shown, wherein... Figure 3 (a) is a 3D view of the first gear position. Figure 3 (b) is a half-section view of the first gear position; Figure 4 A schematic diagram of the two-stage reamer provided in this disclosure in its second position is shown, wherein... Figure 4 (a) is a 3D view of the second gear position. Figure 4 (b) is a half-section view of the second gear position; Figure 5 A schematic diagram of the self-renewing shaft in the two-stage drilling reamer provided in this disclosure is shown, wherein... Figure 5(a) is an assembly state diagram of the self-renewing shaft. Figure 5 (b) is an exploded view of the self-updating axis; Figure 6 A partially enlarged assembly view of the self-renewing shaft in the two-stage drilling reamer provided in this disclosure is shown, wherein Figure 6 (a) is an enlarged assembly view of the ratchet section. Figure 6 (b) is an enlarged view of the self-locking mechanism assembly.

[0019] Explanation of the labels in the diagram: 1. Housing; 11. Fixed pin; 2. Shift shaft; 21. First shaft section; 22. Second shaft section; 23. Shift shaft section; 24. Shift groove; 241. Zigzag groove; 242. Reset groove; 243. First gear groove; 244. Second gear groove; 3. First-stage rock-breaking blade; 31. First-step hole; 32. Cutting wheel; 33. Self-renewing shaft; 331. Ratchet section; 332. Shaft key section; 333. Self-locking section; 34. Pawl; 35. Self-locking block; 4. Secondary rock-breaking blade; 41. Second step hole; 42. Polycrystalline diamond cutting teeth; 5. Blade return spring; 6. Spindle return spring. Detailed Implementation

[0020] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0021] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0022] Combination Figure 1 and Figure 2 As shown, this embodiment of the present disclosure provides a two-stage drilling reamer, which includes a housing 1, a shift shaft 2, a first-stage rock-breaking blade 3, and a second-stage rock-breaking blade 4; the housing 1 has a through-cavity formed vertically inside; the shift shaft 2 is movably inserted through the through-cavity; the first-stage rock-breaking blade 3 is movably inserted through the shell wall of the housing 1, having a rock-breaking side that can extend out of the housing 1 and an abutting side located in the through-cavity; the second-stage rock-breaking blade 4 is spaced above the first-stage rock-breaking blade 3 and movably inserted through the shell wall of the housing 1, having a rock-breaking side that can extend out of the housing 1 and an abutting side located in the through-cavity; Under the action of external force, the shift shaft 2 can descend vertically to the trigger position in the through cavity and simultaneously push against the contact side of the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4, so that the rock-breaking side of the two can extend out of the shell 1 at different lengths.

[0023] The dual-stage reamer provided in this embodiment can be used simultaneously with the drill bit and screw drill bit. For example, male and female threads can be provided at the upper and lower ends of the housing 1 for installation and connection with the drill bit and screw drill bit. When performing the reaming function, the displacement and hydraulic pressure can be increased by the ground pump system. The hydraulic force causes the shift shaft 2 to descend vertically to the trigger position in the through cavity. In this way, the shift shaft 2 can simultaneously push against the contact side of the primary rock-breaking blade 3 and the secondary rock-breaking blade 4, so that the rock-breaking side of the primary rock-breaking blade 3 and the secondary rock-breaking blade 4 can extend out of the housing 1 at different lengths. Thus, the primary rock-breaking blade 3, which is set at the lower end, can be used for initial reaming, and the secondary rock-breaking blade 4, which is set at the upper end, can be used for secondary reaming.

[0024] Furthermore, the shift shaft 2 can be equipped with abutment shaft sections of different diameters, and the lower end face of the abutment shaft section can be provided with a tapered surface. In this way, the shift shaft 2 can generate abutment action on the contact side of the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 through the abutment shaft sections of different diameters, so that the rock-breaking side of the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 can extend out of the housing 1 at different lengths, thereby performing different diameter expansion functions.

[0025] In summary, the dual-stage reamer provided in this embodiment, during a single drilling run, allows for different outgoing lengths of the primary rock-breaking blade 3 and the secondary rock-breaking blade 4 by changing the specific abutment position of the shift shaft 2, thereby flexibly enabling the reamer to enlarge the wellbore to different sizes. Furthermore, the sequential enlargement method using the primary rock-breaking blade 3 and the secondary rock-breaking blade 4 effectively solves the problem of frequent tripping and reamer replacement during multi-stage reaming operations, improving drilling efficiency and saving the cost of tripping and replacing reamers of different sizes. Moreover, the sequential reaming and rock-breaking by the primary rock-breaking blade 3 and the secondary rock-breaking blade 4 achieves efficient rock breaking and enlargement while effectively coping with complex formation environments during drilling, avoiding rapid tool wear caused by a single rock-breaking method, and extending the service life of the dual-stage reamer.

[0026] In one embodiment, the shift shaft 2 includes a first shaft segment 21 and a second shaft segment 22 fixedly connected; the first shaft segment 21 has a first radial dimension and is capable of abutting the abutting side of the first-stage rock-breaking blade 3 along its own radial direction; the second shaft segment 22 has a second radial dimension and is capable of abutting the abutting side of the second-stage rock-breaking blade 4 along its own radial direction. When the first shaft section 21 moves downward in the through cavity, it can push the first-stage rock-breaking blade 3 out of the shell 1 at different lengths; when the second shaft section 22 moves downward in the through cavity, it can push the second-stage rock-breaking blade 4 out of the shell 1 at different lengths.

[0027] Specifically, in combination Figure 2 and Figure 3 Further details (of which, Figure 2 Figure b shows the initial position of shift shaft 2 in the through-cavity; Figure 3 Figure b shows the shift shaft 2 in the first descending position through the cavity. The first radial dimension of the first shaft segment 21 of the shift shaft 2 can be set to be smaller than the second radial dimension of the second shaft segment 22, and the first shaft segment 21 and the second shaft segment 22 can be fixedly connected by a connecting shaft segment of a smaller size.

[0028] When the shift shaft 2 moves downward in the through cavity, the first shaft section 21 and the second shaft section 22 can move downward synchronously. The first shaft section 21 can push the first-stage rock-breaking blade 3 out of the housing 1, and the second shaft section 22 can push the second-stage rock-breaking blade 4 out of the housing 1. In this way, the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 can be pushed out of the outer wall of the housing 1 at the same time during the diameter expansion operation by means of linkage pushing.

[0029] Furthermore, it is worth noting that the lower end surfaces of the first shaft segment 21 and the second shaft segment 22 can be set as conical surfaces. In this way, when the shift shaft 2 moves downward in the through cavity, the conical surfaces at the lower ends of the first shaft segment 21 and the second shaft segment 22 can more smoothly squeeze and abut against the contact sides of the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4.

[0030] In one embodiment, multiple primary rock-breaking blades 3 and secondary rock-breaking blades 4 are arranged in a circular array around the central axis of the shell 1; the contact sides of multiple primary rock-breaking blades 3 together form a first stepped hole 31 with varying diameter; the contact sides of multiple secondary rock-breaking blades 4 together form a second stepped hole 41 with varying diameter. When the first shaft segment 21 is inserted into the upper section of the first stepped hole 31, the second shaft segment 22 is simultaneously inserted into the upper section of the second stepped hole 41, and the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 extend out of the shell 1 at the first length. When the first shaft segment 21 is inserted into the lower section of the first stepped hole 31, the second shaft segment 22 is simultaneously inserted into the lower section of the second stepped hole 41, and the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 extend out of the shell 1 at the second length. Specifically, in combination Figure 3 and Figure 4 Further details ( Figure 3 Figure b shows the shift shaft 2 in the first descending position of the through-cavity. Figure 4 Figure b shows the shift shaft 2 in the second descending position of the through cavity. It is possible, but not limited to, setting three, four, five or other quantities of primary rock-breaking blades 3 and secondary rock-breaking blades 4, and arranging them in a circular array along the central axis of the housing 1. In this way, the contact sides of several primary rock-breaking blades 3 can form a first stepped hole 31 with a changing diameter, and the contact sides of several secondary rock-breaking blades 4 can form a second stepped hole 41 with a changing diameter.

[0031] like Figure 3 As shown in Figure b, at this time, the first shaft segment 21 is inserted into the upper hole segment of the first stepped hole 31, and the second shaft segment 22 is simultaneously inserted into the upper hole segment of the second stepped hole 41. At this time, the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 extend out of the shell 1 in the first length state (for example, in the first length state, the first-stage rock-breaking blade 3 extends outward from the shell 1 by 2cm, and the second-stage rock-breaking blade 4 extends outward from the shell 1 by 4cm). like Figure 4 As shown in Figure b, at this time, the first shaft segment 21 is inserted into the lower section of the first stepped hole 31, and the second shaft segment 22 is simultaneously inserted into the lower section of the second stepped hole 41. At this time, the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 extend out of the shell 1 in the second length state (for example, in the second length state, the first-stage rock-breaking blade 3 extends outward from the shell 1 by 5cm, and the second-stage rock-breaking blade 4 extends outward from the shell 1 by 7cm). Thus, by synchronously adjusting the specific insertion depths of the first shaft segment 21 and the second shaft segment 22 in the first step hole 31 and the second step hole 41 respectively, the actual extension lengths of the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 can be changed accordingly. This allows the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 to sequentially expand the hole and break the rock in stages, further solving the problem of frequent drilling and replacement of the reamer for multi-stage diameter expansion, improving the working efficiency of drilling operations, and further reducing the rapid wear of the cutting tools caused by a single rock-breaking method.

[0032] Of course, theoretically, by increasing the number of hole segments in the first step hole 31 and the second step hole 41, and by increasing the step size of the first shaft segment 21 and the second shaft segment 22, the two can be combined to achieve more levels of gear replacement for the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4.

[0033] In one embodiment, the housing 1 has a fixed stop pin 11 fixedly inserted in its own housing wall; the shift shaft 2 has a shift shaft section 23, and the outer peripheral wall of the shift shaft section 23 is provided with a shift groove 24 for the fixed stop pin 11 to be inserted and fitted; when the shift shaft 2 moves vertically to different trigger positions in the through cavity, the fixed stop pin 11 is correspondingly limited and blocked in different gear positions in the shift groove 24.

[0034] Specifically, in combination Figure 2 , Figure 3 and Figure 4 Further details ( Figure 2 Figure a shows the shift shaft section 23 in the reset state. Figure 3 Figure a shows the shift shaft segment 23 in the first gear position. Figure 4 Figure a shows the shift shaft section 23 in the second gear position. Since the fixed pin 11 is fixedly installed in the shell wall of the housing 1, the fixed pin 11 will move along the shift groove 24 in the shift shaft section 23 when the shift shaft 2 moves up and down in the through cavity in the housing 1 (in reality, the fixed pin 11 does not move, but the shift groove 24 moves up and down).

[0035] When the shift shaft 2 is in its initial position in the through-cavity (i.e.) Figure 2 (As shown in Figure b), the fixed gear pin 11 is correspondingly stopped at the lowest reset point of the shift groove 24 (i.e., Figure 2 (as shown in Figure a); when the shift shaft 2 is in the first descending position in the through-cavity (i.e. Figure 3 (As shown in Figure b), the fixed gear pin 11 is positioned at the first gear point in the center of the shift groove 24 (i.e., Figure 3 (as shown in Figure a); when the shift shaft 2 is in the second descending position in the through-cavity (i.e. Figure 4 (As shown in Figure b), the fixed gear pin 11 is correspondingly stopped at the second gear position at the top of the shift groove 24 (i.e., Figure 4 (The location shown in Figure a).

[0036] By setting the aforementioned fixed pin 11 and shift groove 24, the shift shaft 2 can be limited and fixed at the initial position, the first descending position and the second descending position in the through cavity. This allows the shift shaft 2 to remain relatively fixed when it pushes against the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4, thereby ensuring that the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 maintain a stable extension length in both the first length state and the second length state of extending out of the housing 1.

[0037] In one embodiment, the shift groove 24 includes a zigzag groove 241, a reset groove 242, a first gear groove 243, and a second gear groove 244; the zigzag groove 241 is serrated and surrounds the outer peripheral wall of the shift shaft section 23; the reset groove 242 is straight and is vertically connected to the lower corner of the zigzag groove 241; the first gear groove 243 is straight and is vertically connected to the upper corner of the zigzag groove 241; the second gear groove 244 is straight and is vertically connected to the upper corner of the zigzag groove 241. The first gear slot 243 and the second gear slot 244 are arranged alternately, and the length of the first gear slot 243 is less than the length of the second gear slot 244.

[0038] Specifically, in combination Figure 2 , Figure 3 and Figure 4 To explain in further detail, the zigzag groove 241 in the shift groove 24 is configured as a sawtooth shape and is formed around the outer peripheral wall of the shift shaft section 23. Furthermore, the reset groove 242 is vertically connected to the lower corner of the zigzag groove 241, and the first gear groove 243 and the second gear groove 244 are vertically spaced and connected to the upper corner of the zigzag groove 241. Thus, when the shift groove 24 moves downward with the shift shaft 2, the stationary pin 11 can move upward along the reset groove 242 into the zigzag groove 241, then through the upward-sloping section of the zigzag groove 241 and engage at the very top of the first gear groove 243 (e.g., ...). Figure 3 As shown in Figure a), at this point, the shift shaft 2 can be fixed in the first gear position, so that the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 extend out of the housing 1 in the first length state.

[0039] When it is necessary to shift the gear shaft 2 to the second gear, first briefly raise the gear shaft 2 a certain distance, and the fixed gear pin 11 can then move downwards along the first gear return groove 243 through the tortuous groove 241 into the reset groove 242; then lower the gear shaft 2 further a certain distance, at which point the fixed gear pin 11 can rise again from the reset groove 242, and again move along the upward-sloping section of the tortuous groove 241 to engage at the very top of the second gear return groove 244 (e.g., Figure 4 As shown in Figure a), at this point, the shift shaft 2 can be fixed in the second gear position, so that the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 extend out of the housing 1 in the second length state.

[0040] In one embodiment, the dual-stage drilling reamer further includes a blade return spring 5; the blade return spring 5 is connected between the housing 1 and the first-stage rock-breaking blade 3, and between the housing 1 and the second-stage rock-breaking blade 4, and is used to apply a spring force to the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 to move inward toward the interior of the housing 1.

[0041] Specifically, in combination Figure 1 To explain in further detail, the blade return spring 5 can be, but is not limited to, a compression spring, and can always provide elastic force to the primary rock-breaking blade 3 and the secondary rock-breaking blade 4 to retract toward the inside of the housing 1. In this way, when the shift shaft 2 in the dual-stage drilling reamer is in or switched to the reset state, the blade return spring 5 can use its own elastic force to cause the primary rock-breaking blade 3 and the secondary rock-breaking blade 4 to retract and return to their original position in the housing 1.

[0042] However, when the shift shaft 2 in the dual-stage drilling reamer is in or switching between the first and second gear positions, the pushing force generated by the shift shaft 2 on the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 can overcome the elastic force of the blade return spring 5, allowing the blade return spring 5 to further elastically contract. In this way, the first-stage rock-breaking blade 3 and the second-stage rock-breaking blade 4 can extend out of the outer wall of the housing 1 at different lengths.

[0043] In one embodiment, the dual-stage reamer also includes a mandrel return spring 6; the mandrel return spring 6 is connected between the housing 1 and the shift shaft 2, and is used to apply an upward return force to the shift shaft 2.

[0044] Specifically, in combination Figure 1 To elaborate further, the spindle return spring 6 can also be, but is not limited to, a compression spring, and can always provide the shift shaft 2 with an upward force toward the top of the housing 1. In this way, when the hydraulic force acts downward on the shift shaft 2, the hydraulic force can overcome the spring force of the spindle return spring 6, thereby enabling the shift shaft 2 to descend from the reset state and switch to the first gear state or the second gear state. When the hydraulic force disappears or is less than the spring force of the spindle return spring 6, the spindle return spring 6 can drive the shift shaft 2 to automatically rise toward the top of the housing 1, enabling the shift shaft 2 to rise from the first gear state or the second gear state and switch to the reset state.

[0045] In one embodiment, a cutting wheel 32 is provided in the primary rock-breaking blade 3; the cutting wheel 32 is rotatably mounted on the primary rock-breaking blade 3 via a self-renewing shaft 33; wherein, during the process of the primary rock-breaking blade 3 extending out of the housing 1, the self-renewing shaft 33 can drive the cutting wheel 32 to rotate unidirectionally by a certain angle.

[0046] Specifically, in combination Figure 1 and Figure 5 To elaborate further, the cutting wheel 32 in the primary rock-breaking blade 3 can be, but is not limited to, made of tungsten carbide, and the self-renewing shaft 33 can be, but is not limited to, a ratchet shaft. Thus, each time the primary rock-breaking blade 3 extends out of the housing 1, the self-renewing shaft 33 can drive the cutting wheel 32 to rotate unidirectionally by a certain angle (such as 15°, 20°, or 30°). In this way, during one working cycle of the primary rock-breaking blade 3's expansion and contraction, the cutting wheel 32 will perform a self-renewal rotation, turning the cutting teeth from the previous operation into the recycling and renewing the unused cutting teeth, thereby improving the service life of the primary rock-breaking blade 3 and the efficiency of the diameter expansion operation.

[0047] In one embodiment, the housing 1 has an opening for the extension and retraction of the primary rock-breaking blade 3, and a pawl 34 and a self-locking block 35 are correspondingly provided in the opening; the self-renewing shaft 33 includes a ratchet part 331, a key part 332 and a self-locking part 333 connected coaxially in sequence; when the primary rock-breaking blade 3 drives the cutting wheel 32 to extend out of the opening, the pawl 34 and the ratchet part 331 cooperate to form a check ratchet mechanism, and drive the self-renewing shaft 33 and the cutting wheel 32 to rotate unidirectionally by a certain angle, and cause the self-locking part 333 and the self-locking block 35 to abut and lock.

[0048] Specifically, in combination Figure 5 ( Figure 5 (Figures a and b in the text) and Figure 6 To elaborate further, a pawl 34 and a self-locking block 35 are correspondingly provided in the opening of the housing 1 where the first-stage rock-breaking blade 3 is installed, and a ratchet part 331 and a self-locking part 333 are correspondingly provided in the self-renewing shaft 33. Thus, when the first-stage rock-breaking blade 3 drives the cutting wheel 32 to extend out of the opening, the pawl 34 and the ratchet part 331 can cooperate to form a check ratchet mechanism, which can drive the self-renewing shaft 33 and the cutting wheel 32 to rotate unidirectionally by a certain angle (e.g., ...). Figure 6 (As shown in Figure a); and when the cutting wheel 32 rotates to its unidirectional position, the self-locking part 333 can move with the cutting wheel 32 to abut against the self-locking block 35. Since the circumferential surface of the self-locking part 333 is polygonal, the self-locking part 333 can thus perform anti-rotation blocking and limiting with the self-locking block 35 (as shown in Figure a). Figure 6 (As shown in Figure b), thus further ensuring that the cutting wheel 32 cannot rotate during the eye-opening cutting of the first-stage rock-breaking blade 3.

[0049] Specifically, combined with Figure 5 The diagram in Figure b provides a detailed explanation. The ratchet part 331, the key part 332, and the self-locking part 333 are coaxially arranged, and the cutting wheel 32 is fitted into the key part 332 via the key, so that the self-renewing shaft 33 and the cutting wheel 32 can rotate synchronously.

[0050] When the first-stage rock-breaking blade 3 drives the cutting wheel 32 to extend out of the opening, the self-renewing shaft 33 will also be synchronously driven to extend out of the opening. At this time, combined with Figure 6 Figures a and b provide a detailed explanation. During the process of the ratchet portion 331 extending from the opening in the self-updating shaft 33, the corresponding pawl 34 within the opening forms a check ratchet mechanism with the ratchet portion 331. That is, the pawl 34 ensures that the ratchet portion 331 can only perform [returning action]. Figure 6 The clockwise rotation shown in Figure a is as follows ( Figure 6 (As shown by the curved arrow in Figure a); and at this time, the self-locking part 333 in the self-updating axis 33 will also extend its opening synchronously (as shown by the arrow in Figure a). Figure 6As shown by the straight arrow in Figure b), in the early stage when the self-locking part 333 extends out of the opening, the self-locking part 333 will rotate synchronously with the ratchet part 331. However, in the later stage when the self-locking part 333 extends out of the opening, the ratchet part 331 is no longer pushed and rotated by the pawl 34. At this time, the self-locking part 333 also stops rotating, and the self-locking part 333 can also abut against the self-locking block 35 in the opening. Since the circumference of the self-locking part 333 is polygonal, the self-locking part 333 can anti-rotation and locking limit the self-locking block 35.

[0051] It is also worth noting that, to ensure that one side of the polygonal circumferential surface of the self-locking part 333 can be flush with the self-locking block 35 after the self-locking part 333 extends out of the opening, the number of sides of the polygonal surface of the self-locking part 333 can be adjusted according to the rotation angle of the ratchet part 331 after being pushed by the pawl 34 each time. For example, if the ratchet part 331 rotates 10° each time it is pushed by the pawl 34, then the number of sides of the polygonal surface of the self-locking part 333 can be set to 360° / 10°=36. In addition, when the first-stage rock-breaking blade 3 drives the cutting wheel 32 to retract into the opening, in the first half of the retraction, the self-locking block 35 will still block and limit the self-locking part 333, and the self-renewing shaft 33 will not rotate at this time; in the second half of the retraction, the ratchet part 331 will push against the pawl 34 upward, so that the pawl 34 will bounce upward, but the ratchet part 331 will not rotate at this time.

[0052] In one embodiment, polycrystalline diamond cutting teeth 42 are provided on the rock-breaking side of the secondary rock-breaking blade 4.

[0053] Specifically, in combination Figure 5 To elaborate further, polycrystalline diamond cutting teeth 42 are provided on the rock-breaking side of the secondary rock-breaking blade 4. Polycrystalline diamond (PCD), also known as polycrystalline diamond, is a man-made superhard material with high hardness, wear resistance, toughness and self-sharpening properties. This can effectively ensure the service life of the secondary rock-breaking blade 4 and the efficiency of the diameter expansion operation.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A two-stage drilling reamer, characterized in that, include: The shell (1) has a through cavity opened in the vertical direction inside; The shift shaft (2) is movably inserted into the through cavity; The first-stage rock-breaking blade (3) is movably installed in the shell wall of the shell (1), and has a rock-breaking side that can extend out of the shell (1) and an abutting side located in the through cavity; The secondary rock-breaking blade (4) is spaced above the primary rock-breaking blade (3) and is movably inserted into the shell wall of the shell (1). It has a rock-breaking side that can extend out of the shell (1) and an abutting side located in the through cavity. Under the action of external force, the shift shaft (2) can descend vertically to the trigger position in the through cavity and simultaneously push against the contact side of the first-stage rock-breaking blade (3) and the second-stage rock-breaking blade (4) so ​​that the rock-breaking side of the two can extend out of the shell (1) at different lengths.

2. The dual-stage reamer as described in claim 1, characterized in that, The shift shaft (2) includes a first shaft section (21) and a second shaft section (22) that are fixedly connected. The first shaft segment (21) has a first radial dimension and is able to abut against the contact side of the first-stage rock-breaking blade (3) along its own radial direction; The second shaft segment (22) has a second radial dimension and is able to abut against the contact side of the secondary rock-breaking blade (4) radially. When the first shaft segment (21) moves downward in the through cavity, the first shaft segment (21) can push the first-stage rock-breaking blade (3) out of the shell (1) at different lengths. When the second shaft segment (22) moves downward in the through cavity, the second shaft segment (22) can push the secondary rock-breaking blade (4) out of the shell (1) at different lengths.

3. The dual-stage reamer as described in claim 2, characterized in that, The first-stage rock-breaking blade (3) and the second-stage rock-breaking blade (4) are arranged in a ring array around the central axis of the shell (1); The contact sides of multiple first-stage rock-breaking blades (3) together form a first stepped hole (31) with varying diameter. The contact sides of multiple secondary rock-breaking blades (4) together form a second stepped hole (41) with varying diameter. When the first shaft segment (21) is inserted into the upper hole of the first stepped hole (31), the second shaft segment (22) is simultaneously inserted into the upper hole of the second stepped hole (41), and the first-stage rock-breaking blade (3) and the second-stage rock-breaking blade (4) extend out of the shell (1) in the first length state. When the first shaft segment (21) is inserted into the lower section of the first stepped hole (31), the second shaft segment (22) is simultaneously inserted into the lower section of the second stepped hole (41), and the first-stage rock-breaking blade (3) and the second-stage rock-breaking blade (4) extend out of the shell (1) in the second length state.

4. The dual-stage reamer as described in claim 3, characterized in that, The shell (1) has a fixed stop pin (11) fixedly inserted in its shell wall. The shift shaft (2) has a shift shaft section (23), and the outer peripheral wall of the shift shaft section (23) is provided with a shift groove (24) for the fixed pin (11) to be inserted and fitted. When the shift shaft (2) moves vertically to different trigger positions in the through cavity, the fixed pin (11) is correspondingly limited and blocked at different gear positions in the shift groove (24).

5. The dual-stage reamer as described in claim 4, characterized in that, The shifting channel (24) includes: The meandering groove (241) is serrated and surrounds the outer peripheral wall of the shift shaft section (23); The reset channel (242) is straight and is vertically connected to the lower corner of the tortuous channel (241); The first gear groove (243) is straight and is vertically connected to the upper corner of the tortuous groove (241); The second gear groove (244) is straight and is vertically connected to the upper corner of the tortuous groove (241); The first gear slot (243) and the second gear slot (244) are arranged alternately and interleaved, and the length of the first gear slot (243) is less than the length of the second gear slot (244).

6. The dual-stage reamer as described in claim 1, characterized in that, The dual-stage drilling reamer also includes a cutter return spring (5); The blade return spring (5) is connected between the housing (1) and the first-stage rock-breaking blade (3) and between the housing (1) and the second-stage rock-breaking blade (4), and is used to apply a spring force to the first-stage rock-breaking blade (3) and the second-stage rock-breaking blade (4) to move inward toward the interior of the housing (1).

7. The dual-stage reamer as described in claim 1, characterized in that, The dual-stage drilling reamer also includes a mandrel return spring (6). The spindle return spring (6) is connected between the housing (1) and the shift shaft (2) and is used to apply an upward return force to the shift shaft (2).

8. The two-stage reamer according to any one of claims 1 to 7, characterized in that, The first-stage rock-breaking blade (3) is equipped with a cutting wheel (32); The cutting wheel (32) is rotatably mounted on the first-stage rock-breaking blade (3) via a self-renewing shaft (33). During the process of the first-stage rock-breaking blade (3) extending out of the housing (1), the self-renewing shaft (33) can drive the cutting wheel (32) to rotate unidirectionally by a certain angle.

9. The dual-stage reamer as described in claim 8, characterized in that, An opening is provided in the housing (1) for the extension and retraction of the first-stage rock-breaking blade (3), and a pawl (34) and a self-locking block (35) are provided in the opening. The self-renewing shaft (33) includes a ratchet part (331), a key part (332) and a self-locking part (333) that are coaxially connected in sequence. When the first-stage rock-breaking blade (3) drives the cutting wheel (32) to extend out of the opening, the pawl (34) and the ratchet part (331) cooperate to form a check ratchet mechanism, and drive the self-renewing shaft (33) and the cutting wheel (32) to rotate in one direction by a certain angle, and make the self-locking part (333) and the self-locking block (35) abut and lock.

10. The dual-stage reamer as described in claim 8, characterized in that, Polycrystalline diamond cutting teeth (42) are provided on the rock-breaking side of the secondary rock-breaking blade (4).

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