Drill bit assembly and reaming equipment

Abstract

The invention relates to a drill bit assembly (100) and a reaming apparatus. The drill bit assembly (100) has an axis of revolution (1a) and comprises at least two drill bit units (10) connected in series in the direction of the axis of revolution (1a). Each drill bit unit (10) comprises a base (11) and a cutting knife (12), the base (11) is connected with the base (11) of the adjacent drill bit unit (10), the cutting knife (12) is connected to the periphery of the base (11), and the cutting knife (12) is provided with a first position which is opened relative to the base (11) and a second position which is retracted relative to the base (11). Wherein the rotation diameter of the drill bit unit (10) when the cutting blade (12) is in the first position is larger than the rotation diameter of the drill bit unit (10) when the cutting blade (12) is in the second position, and when the cutting blade (12) is in the second position, the drill bit unit (10) is configured to be capable of passing through a working hole channel (T) in which the drill bit assembly (100) is located. The reaming equipment comprises the drill bit assembly (100).

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a drill bit assembly and a hole-reaming device. Background Art

[0002] During borehole reaming in rock tunnels and inclined shafts (especially the extra-long inclined pilot shafts of pumped-storage power plants), severe wear of the reamer drill due to hard rock formations or prolonged operation is common. To address this, the commonly used technique involves stopping drilling and completely withdrawing the entire drill bit, along with the multi-stage drill rod, from the reaming operation to allow for repair or replacement. This process is extremely cumbersome, time-consuming, and energy-intensive. Each replacement of the reamer requires manual labor, resulting in high labor intensity, low construction efficiency, and a high risk of safety incidents.

[0003] To address this issue, some related patented technologies attempt to simplify the drill bit maintenance or replacement process by optimizing the drill bit structure, improving the tool linkage form, or innovating the construction method. However, none of these solutions can avoid completely removing the entire worn drill bit and drill rod from the drilling process, which is a high-cost, low-efficiency, and high-risk operation.

[0004] It should be noted that the information disclosed in the background technology section of the present invention is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the Invention

[0005] The present invention provides a drill bit assembly and a hole-reaming device, which can simplify the maintenance or replacement process of the hole-reaming drill bit during the hole-reaming process and improve the hole-reaming construction efficiency.

[0006] According to one aspect of the present invention, a drill bit assembly is provided, the drill bit assembly having a rotation axis and comprising at least two drill bit units connected in series along the rotation axis, the drill bit unit comprising:

[0007] a base connected to the base of an adjacent drill unit; and

[0008] a cutting blade connected to the periphery of the base, the cutting blade having a first position open relative to the base and a second position retracted relative to the base,

[0009] The rotation diameter of the drill unit when the cutter is in the first position is greater than the rotation diameter when the cutter is in the second position, and when the cutter is in the second position, the drill unit is configured to pass through the working channel where the drill assembly is located.

[0010] In some embodiments, the drill head unit includes a plurality of cutting blades uniformly connected to the outer circumference of the base.

[0011] In some embodiments, the drill head unit further includes a driving mechanism disposed between the base and the cutting blade to drive the cutting blade to move relative to the base and switch from the first position to the second position.

[0012] In some embodiments, a protrusion is provided on the outer periphery of the base, the cutting tool is hinged on the protrusion, and the hinge axis is perpendicular to the rotation axis. A receiving hole is provided in the radial middle portion of the base extending along the rotation axis direction, the receiving hole having a first receiving hole end close to the working direction of the drill bit assembly and a second receiving hole end away from the working direction, a first through hole is provided on the hole wall of the receiving hole, and in the direction of the rotation axis, the first through hole is located between the protrusion and the second end of the receiving hole, the driving mechanism includes a piston and a first push rod, the piston is slidably arranged in the receiving hole, the piston is provided with a first guide surface, the radial distance between the first guide surface and the rotation axis changes along the direction of the rotation axis, the first push rod is passed through the first through hole, and one end of the first push rod located radially outside the receiving hole abuts the cutting tool, and the other end abuts the first guide surface, the piston is configured to slide along the rotation axis direction to push the first push rod to move along the first through hole, and then push the cutting tool to rotate around the protrusion to switch from the first position to the second position.

[0013] In some embodiments, the drill head unit further comprises a first limiting structure configured to position the piston axially relative to the accommodating hole after the cutting blade is switched from the first position to the second position.

[0014] In some embodiments, a first guide groove is provided on the outer periphery of the piston, the first push rod rests in the first guide groove, and the first guide surface is formed at the bottom of the first guide groove. In the direction approaching from the first end of the accommodating hole to the second end of the accommodating hole, the radial distance between the bottom of the first guide groove and the axis of rotation gradually decreases.

[0015] In some embodiments, the first guide groove has a first guide groove first end close to the second end of the accommodating hole and a first guide groove second end close to the first end of the accommodating hole. When the cutting knife is in the first position, the first push rod abuts against the first guide groove first end. When the cutting knife is in the second position, the first push rod abuts against the first guide groove second end.

[0016] In some embodiments, a second through hole is further provided on the wall of the receiving hole. In the direction of the rotation axis, the second through hole is located between the protrusion and the first end of the receiving hole.

[0017] The driving mechanism also includes a second push rod, which is inserted into the second through hole. One end of the second push rod located radially outside the accommodating hole abuts against the cutting blade, and the other end abuts against the piston.

[0018] In some embodiments, an extension direction of the first through hole and / or the second through hole is perpendicular to the direction of the rotation axis.

[0019] In some embodiments, a limiting protrusion is provided on the inner wall of the accommodating hole near the second end of the accommodating hole, and the driving mechanism further includes a first spring, which is arranged between the piston and the limiting protrusion.

[0020] In some embodiments, the receiving hole is continuous along the direction of the rotation axis, the piston is sealed with the hole wall of the receiving hole in the circumferential direction, and is provided with a flow channel running through it, the flow channel including a flow channel inlet proximate to the first end of the receiving hole and in fluid communication therewith, and a flow channel outlet proximate to the second end of the receiving hole and in fluid communication therewith. The drill bit unit further includes a pressure relief assembly, which is disposed in the flow channel and has a closed state and an open state. The pressure relief assembly is configured as follows:

[0021] When the fluid pressure at the inlet of the flow channel is less than or equal to the preset pressure, it is in a closed state to block the flow channel, thereby cutting off the fluid connection between the first end of the accommodating hole and the second end of the accommodating hole; and when the fluid pressure at the inlet of the flow channel is greater than the preset pressure, it switches to an open state to release the blockage of the flow channel, thereby allowing the first end of the accommodating hole and the second end of the accommodating hole to be fluidically connected.

[0022] In some embodiments, the flow channel includes a first flow channel section and a second flow channel section that are interconnected. The first flow channel section extends along the rotation axis and is connected to the flow channel inlet. The second flow channel section is perpendicular to the first flow channel section and is connected to the flow channel outlet. The pressure relief assembly includes a valve core disposed in the first flow channel section and a second spring. The second spring is disposed between the valve core and an axial end portion of the first flow channel section near the second end N of the accommodating hole. The valve core is configured as follows:

[0023] When the pressure relief assembly is in the closed state, the connection between the first flow channel section and the second flow channel section is blocked; and when the pressure of the fluid in the first flow channel section is greater than the preset pressure, the second spring is squeezed and moved toward the axial end of the first flow channel section under the push of the fluid to release the blockage of the connection.

[0024] In some embodiments, a fitting portion is provided at the connection between the first flow channel section and the second flow channel section. When the pressure relief assembly is in a closed state, the fitting portion abuts against and adheres to the end of the valve core away from the second spring.

[0025] In some embodiments, when the cutting blade is in the first position, the first spring is compressed and has a first preload, and the second spring is compressed and has a second preload, wherein, in the same drill bit unit, the first preload of the first spring is smaller than the second preload of the second spring; and, along the direction of the rotation axis, the second preload of the second spring of the drill bit unit close to the working direction of the drill bit assembly is smaller than the second preload of the second spring of the drill bit unit away from the working direction of the drill bit assembly.

[0026] In some embodiments, the end of the cutter close to the working direction of the drill bit assembly is provided with a first cutting surface and a second cutting surface connected to the first cutting surface. When the cutter is in the first position, the first cutting surface is perpendicular to the rotation axis and the second cutting surface is parallel to the rotation axis.

[0027] In some embodiments, the cutting blade is provided with a third cutting surface, which is located on a side of the cutting blade facing away from the base. When the cutting blade is in the second position, the third cutting surface is parallel to the rotation axis.

[0028] In some embodiments, a chip discharge groove is provided on a side of the cutting insert close to the base.

[0029] In some embodiments, the chip flutes are sawtooth-type flutes.

[0030] In some embodiments, the bases of two adjacent drill head units are detachably connected.

[0031] According to another aspect of the present invention, there is provided a hole enlarging device comprising:

[0032] The drill bit assembly described above;

[0033] a drill rod connected to the drill bit assembly;

[0034] A drilling rig connected to an end of the drill pipe away from the drill bit assembly, the drilling rig being configured to drive the drill pipe to move along an operating direction, thereby driving the drill bit assembly to move along the operating direction to expand the operating channel;

[0035] a detection device configured to detect an operating state of at least a drill head unit of the drill head assembly in a working position; and

[0036] A controller configured to:

[0037] receiving a signal from a detection device;

[0038] responding to a signal detected by a detection device indicating that the drill unit in the working position is in a failed state, and controlling the cutting blade of the drill unit in the failed state to switch to a second position; and

[0039] The drilling rig is controlled to drive the drill rod to move along the working direction to pull the drill unit in the failed state into the working channel, and the next drill unit connected in series on the side away from the drilling rig of the drill unit in the failed state is moved to the working position.

[0040] Based on the above technical solution, the present invention provides a drill bit assembly comprising at least two drill bit units, and when the cutter is in the second position, the drill bit unit is constructed to be able to pass through the working channel in which the drill bit assembly is located. During the operation of the drill bit assembly, if the cutter of the drill bit unit in the working position is worn, the cutter of the worn drill bit unit can be retracted to the second position, and the drill bit unit can be moved along the working channel to outside its working position. Then, the drill bit unit of the next level connected in series can be moved to the working position to replace the worn drill bit unit, so that the drill bit assembly can continue to perform the reaming operation. This solution eliminates the tedious operation of withdrawing the reamer from the channel to maintain or replace the worn drill bit in the related art, which can effectively reduce the consumption of manpower and material resources and improve the working efficiency of the drill bit assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0042] Figure 1 A schematic structural diagram of a hole expansion device according to an embodiment of the present invention is shown.

[0043] Figure 2 A structural schematic diagram of a drill bit assembly according to an embodiment of the present invention is shown.

[0044] Figure 3 FIG2 shows a structural schematic diagram of a drill bit assembly according to another embodiment of the present invention.

[0045] Figure 4 FIG2 shows a structural schematic diagram of a drill head unit according to an embodiment of the present invention.

[0046] Figure 5 Shown Figure 4 Top view of the drill unit.

[0047] Figure 6 Shown Figure 5 AA cross-sectional view of the drill unit.

[0048] Figure 7 Shown Figure 5 DD cross-sectional view of the drill unit.

[0049] Figure 8 Shown Figure 6 An enlarged view of part G of the drill unit.

[0050] Figure 9 Shown Figure 7 An enlarged view of the H portion of the drill unit.

[0051] Figure 10 FIG2 shows a structural schematic diagram of a drill unit according to another embodiment of the present invention.

[0052] Figure 11 Shown Figure 10 Top view of the drill unit.

[0053] Figure 12 Shown Figure 11 A'-A' cross-sectional view of the drill unit.

[0054] Figure 13 Shown Figure 11 D'-D' cross-sectional view of the drill unit.

[0055] Figure 14 Shown Figure 12 E'-E' cross-sectional view of the drill unit.

[0056] Figure 15 Shown Figure 14 Enlarged view of the F' portion of the drill unit.

[0057] Figure 16 Shown Figure 12 Enlarged view of the G' portion of the drill unit.

[0058] Figure 17 Shown Figure 13 An enlarged view of the H' portion of an embodiment of a drill head unit.

[0059] Figure 18 Shown Figure 13 FIG. 1 is an enlarged view of the H' portion of another embodiment of the drill head unit.

[0060] Figure 19 A control logic diagram of a controller of a hole-reaming device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0061] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0062] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0063] In the field of rock tunnel and inclined shaft drilling and reaming, particularly during the excavation of extremely long, steeply inclined shafts or vertical pilot shafts for pumped-storage power plants, conventional techniques typically involve drilling a pilot hole first, followed by reverse reaming based on this pilot hole. However, these reaming drill bits suffer from low maintenance efficiency and high operational risks when operating in complex rock formations and over long distances.

[0064] To this end, the present invention provides a drill head assembly 100 having a rotation axis 1 a.

[0065] like Figure 1 As shown, in a working state, the drill head assembly 100 is configured to rotate about a rotation axis 1 a to perform a drilling or reaming operation in a working tunnel T in which the drill head assembly 100 is located.

[0066] It should be noted that the drill bit assembly 100 according to the embodiment of the present invention has a wide range of applications and is suitable for excavation and reaming operations in a variety of tunnels. To facilitate a clear explanation of the structure, function, and advantages of the drill bit assembly 100 of the present invention, the following description of the specific embodiment will be based on an application scenario where the operating tunnel T is a lead guide hole in the construction of an inclined shaft of a pumped-storage power station, and the drill bit assembly 100 performs a reaming operation based on this lead guide hole.

[0067] In some implementations, the working tunnel T includes a first tunnel section T1 and a second tunnel section T2. The first tunnel section T1 may be a section of a pilot hole drilled in the initial stage of deviated well construction, and the second tunnel section T2 may be another section of the pilot hole formed after the drilling head assembly 100 is expanded, with a larger hole diameter than the first tunnel section T1.

[0068] In some embodiments, as Figure 1 and Figure 2As shown, the drill head assembly 100 includes at least two drill head units 10 connected in series along the direction of the rotation axis 1a. The drill head unit 10 includes a base 11 and a cutting blade 12. The base 11 is connected to the base 11 of the adjacent drill head unit 10. The cutting blade 12 is connected to the outer periphery of the base 11, and the cutting blade 12 has a first position that is open relative to the base 11 and a second position that is retracted relative to the base 11. The rotation diameter of the drill head unit 10 when the cutting blade 12 is in the first position is larger than the rotation diameter when the cutting blade 12 is in the second position. Moreover, when the cutting blade 12 is in the second position, the drill head unit 10 is configured to be able to pass through the working tunnel T in which the drill head assembly 100 is located. Here, the drill head unit 10 is particularly configured to be able to pass through the first tunnel section T1 in the working tunnel T.

[0069] Next, continue to refer to Figures 1-18 , some embodiments of the drill bit assembly 100 of the present invention are described. Figure 1 and Figure 2 In the illustrated drill head assembly 100, the cutting blades 12 of all drill head units 10 are in a first position; Figure 3 In the illustrated drill head assembly 100 , the cutting blades 12 of the drill head unit 10 of the drill head unit 10 - 1 are all in the second position, while the cutting blades 12 of the drill head unit 10 - 2 , the drill head unit 10 - 3 , the drill head unit 10 - 4 , and the drill head unit 10 - 5 are all in the first position; Figure 4-Figure 9 1 is a schematic structural diagram of the drill unit 10 according to an embodiment of the present invention when the cutting blade 12 is in the first position; Figures 10-18 FIG. 1 is a schematic structural diagram of the drill head unit 10 according to an embodiment of the present invention when the cutting blade 12 is in the second position.

[0070] During the operation of the drill bit assembly 100, it is pulled along the working channel T under the driving action of the drilling rig 300, the drill rod 200 and other components, for example Figure 1-Figure 3 The direction of the speed V+ in FIG schematically shows the forward direction of the drill bit assembly 100 during the hole enlarging operation, that is, the drill bit assembly 100 is pulled upward obliquely. In this working condition, the drill bit unit 10 (e.g. Figure 2 The drill unit 10-1) is the drill unit 10 in the working position.

[0071] When the drill bit assembly 100 rotates about the rotation axis 1a, it is generally driven by the drill rod 200 to rotate as a whole, that is, all drill head units 10 rotate together. When the cutter 12 is in the first position, the cutter 12 can cut the rock wall in the working tunnel T during the rotation of the drill head unit 10, thereby expanding the hole.

[0072] Among the multiple drill units 10 of the drill assembly 100, the drill unit 10 in the working position is subject to more wear and is most likely to be damaged and unable to work normally because it not only needs to cut in its circumference to form a cylindrical cutting surface, but also needs to cut on the wall perpendicular to the forward direction to form an annular cutting surface.

[0073] Here, since the cutting blades 12 are the part that directly contacts the rock wall and performs the cutting action, they are more susceptible to wear than other parts of the drill bit unit 10. Therefore, the wear or failure of the drill bit unit 10 mentioned in the embodiment of the present invention mainly refers to the wear and failure of the cutting blades 12.

[0074] Furthermore, the cutting blade 12 is configured to be detachably connected to the base 11. Thus, after the drill bit assembly 100 completes each reaming operation, the worn cutting blade 12 on the drill bit unit 10 can be removed from the base 11 for maintenance or replacement. In other words, at least the base 11 portion of the drill bit unit 10 can be reused for multiple operations, helping to reduce the operating and maintenance costs of the drill bit unit 10 and the drill bit assembly 100.

[0075] like Figure 1 As shown above, the first tunnel section T1 is a section of the advanced pilot hole drilled in the initial stage of the inclined well construction, and the second tunnel section T2 is another section of the advanced pilot hole that has been enlarged after the hole is enlarged by the drilling head assembly 100. In other words, the second tunnel section T2 is formed after cutting by the drill bit assembly 100. Therefore, the hole diameter of the second tunnel section T2 is equal to the rotation diameter of the drill head unit 10 when the cutter 12 is in the first position (in Figure 2 shown as D1).

[0076] You can refer to Figure 5 , shows a top view of the drill unit 10 when the cutting blade 12 is in a first position opened relative to the base 11, and the rotary diameter of the drill unit 10 at this time is Figure 5 Shown as D1.

[0077] The rotation diameter of the drill unit 10 when the cutting blade 12 is in the second position ( Figure 2 and Figure 3 The hole diameter of the first hole section T1 is slightly smaller than that of the first hole section T2.

[0078] You can also refer to Figure 11 , shows a top view of the drill unit 10 when the cutting blade 12 is in the second position retracted relative to the base 11, and the rotary diameter of the drill unit 10 at this time is Figure 11 Shown as D2.

[0079] Optionally, the rotation diameter of the cutting blade 12 when in the second position is configured to be 3 to 8 cm smaller than the aperture of the first tunnel section T1. As an example, the rotation diameter of the cutting blade 12 when in the second position is 16 cm, and the aperture of the first tunnel section T1 is 20 cm.

[0080] Based on this, reference Figure 3 As shown, after the cutting blade 12 is retracted from the first open position relative to the base 11 to the second position close to the base 11, the drill unit 10 in which it is located can be moved into the first tunnel section T1. Figure 2 and Figure 3 As shown in , if the drill unit 10-1 is worn to the point where it cannot work normally during the operation of the drill assembly 100, the cutter 12 can be retracted to the second position and further pulled into the first channel section T1 by driving components such as the drill rig 300 and the drill rod 200. At this time, the drill unit 10-2 located downstream of the drill unit 10-1 can be moved to the working position where the drill unit 10-1 was originally located, so that the drill assembly 100 can continue to perform the hole expansion operation.

[0081] Similarly, if the drill unit 10-2 wears out during subsequent operations, the drill unit 10-3 downstream of the drill unit 10-2 can be used to replace it, as described above. The following drill units 10-4 and 10-5 work in the same manner.

[0082] That is, when the cutting blade 12 is in the first position, the drill unit 10 is in an operating state capable of performing a hole enlarging operation. When the cutting blade 12 is in the second position, the drill unit 10 is in a non-operating state with the blade retracted, and can enter the first tunnel section T1, thereby not affecting the normal operation of other drill units 10 in an operating state.

[0083] In the embodiment of the present invention, a plurality of drill head units 10 connected in series are also referred to as multi-stage drill head units 10. For any one stage of drill head unit 10, the drill head unit 10 of another stage connected to the end thereof away from the advancing direction of the drill head assembly 100 is the drill head unit 10 of the next stage relative to the drill head unit 10 closer to the advancing direction of the drill head assembly 100. Figure 2 Taking the drill head assembly 100 as an example, the drill head unit 10-2 is the next level of the drill head unit 10-1, the drill head unit 10-3 is the next level of the drill head unit 10-2, the drill head unit 10-4 is the next level of the drill head unit 10-3, and the drill head unit 10-5 is the next level of the drill head unit 10-4.

[0084] According to an embodiment of the present invention, by configuring the drill bit assembly 100 to include at least two drill bit units 10, and configuring the drill bit units 10 to be able to pass through the working tunnel T in which the drill bit assembly 100 is located, particularly the first tunnel section T1, when the cutter 12 is in the second position, if a drill bit unit 10 in the working position becomes worn during operation of the drill bit assembly 100, the worn drill bit unit 10 can be replaced by the drill bit unit 10 at the next level to continue the reaming operation. This solution eliminates the need to withdraw the drill bit assembly 100 from the working tunnel T to maintain or replace the worn drill bit unit 10, and can quickly restore the drill bit assembly 100 to a normal operating state to continue the reaming operation.

[0085] In actual application, the number of drill bit units 10 connected in series can be adjusted according to the operation requirements. For example, the number of drill bit units 10 required to complete the hole expansion operation can be calculated before the operation is carried out based on factors such as the characteristics of the rock in the formation Q (rock composition, hardness, etc.), the required drilling distance (i.e., the length of the operation tunnel T), and the material of the cutting blade 12. Figure 1-Figure 3 In the embodiment of the present invention, the drill head assembly 100 includes five drill head units 10 connected in series.

[0086] Optionally, to ensure that the entire working tunnel T is enlarged in one drilling process without having to replace the drill bit assembly 100 midway, one or two more drill bit units 10 may be appropriately configured in the drill bit assembly 100 based on the calculation results. For example, if it is calculated that n drill bit units 10 are required to complete the enlargement of the entire working tunnel T, then n+1 or n+2 drill bit units 10 may be configured in the drill bit assembly 100.

[0087] Furthermore, two adjacent drill units 10 in the drill assembly 100 are configured to be detachably connected. This allows for flexible and rapid connection of multiple drill units 10 in preparation for construction work, based on the calculated number of drill units 10 required. After the hole expansion operation is complete, the multiple drill units 10 can also be easily disassembled for storage and maintenance.

[0088] Optionally, the bases 11 of two adjacent drill head units 10 are detachably connected. For example, the bases 11 of two adjacent drill head units 10 are connected by threads.

[0089] In some embodiments, reference Figure 4 and Figure 10 As shown, the drill head unit 10 includes a plurality of cutting blades 12 , which are uniformly connected to the outer circumference of the base 11 .

[0090] Arranging multiple cutting blades 12 can increase the cutting capacity of the drill unit 10. Furthermore, the multiple cutting blades 12 are evenly distributed circumferentially around the base 11, which can achieve circumferential balance of the reaction force to the cutting force borne by the drill unit 10 as a whole, helping to reduce vibration and runout, thereby increasing the service life of the drill unit 10.

[0091] Optionally, the number of cutters 12 provided on each drill bit unit 10 can be adjusted based on parameters such as the size of the set expansion diameter, rock hardness, and cutting speed, for example, three, four, five, or six cutters 12 can be arranged. As some implementations, when the rock formation is harder or higher expansion efficiency is required, a larger number of cutters can be configured, or the number of cutters 12 can be appropriately reduced while increasing the strength of each cutter 12.

[0092] Optionally, different hole enlarging effects can be achieved by adjusting the length or arrangement angle of the cutting blade 12 .

[0093] Optionally, the shape and structure of the cutting blade 12 can be selected in a variety of ways, such as a long strip structure.

[0094] As some implementations, the length of the cutting blade 12 is changed, referring to Figure 2 The length L shown in FIG. 1 can change the diameter of the hole being reamed of the hole reaming assembly 100. As an example, the length L can be 20 cm, 30 cm, 40 cm, etc.

[0095] As another implementation, the arrangement angle of the cutting blade 12 is changed, referring to Figure 2 The angle α shown in FIG, i.e., the angle between the cutting blade 12 and the base 11 in the first position, i.e., the angle between the cutting blade 12 and the rotation axis 1a, can also change the diameter of the hole being reamed by the reaming assembly 100. As an example, the angle α can be 25 degrees, 30 degrees, 45 degrees, etc.

[0096] In some embodiments, reference Figure 4 、 Figure 7 and Figure 10 As shown, the cutter 12 is provided with a first cutting surface 12a and a second cutting surface 12b, which are located at one end of the cutter 12 close to the working direction of the drill bit assembly 100. The first cutting surface 12a and the second cutting surface 12b are both provided with a plurality of cutting teeth for cutting the rock wall.

[0097] like Figure 2 As shown, the working direction of the drill bit assembly 100 is shown as its forward direction along the working tunnel T (schematically shown in the direction of speed V+).

[0098] When the cutter 12 is in the first position, the first cutting surface 12a is configured to cut the rock wall facing the working direction of the drill bit assembly 100. Optionally, when the cutter 12 is in the first position, the first cutting surface 12a is perpendicular to the rotation axis 1a, thereby cutting an annular surface on the rock wall that is perpendicular to the rotation axis 1a, that is, perpendicular to the axis of the working tunnel T.

[0099] Optionally, when the cutter 12 is in the first position, the second cutting surface 12b is parallel to the rotation axis 1a. In this case, the second cutting surface 12b can closely contact the hole wall surrounding its outer periphery and perform cutting. This not only helps to cut a smoother hole wall, but also provides guidance and support for the drill unit 10, thereby improving the rotational stability of the drill unit 10 and the overall operational stability of the drill assembly 100.

[0100] In some embodiments, reference Figure 4 、 Figure 7 and Figure 10 As shown, the cutting blade 12 is provided with a third cutting surface 12c. The third cutting surface 12c is located on the side of the cutting blade 12 away from the base 11. Figure 13 As shown, in some implementations, when the cutter 12 is in the second position, the third cutting surface 12c is parallel to the rotation axis 1a. Thus, after the cutter 12 of the drill unit 10 is retracted and the drill unit 10 moves into the first tunnel section T1, the third cutting surface 12c also rotates during the rotation of the drill unit 10, forming a rotating surface that matches the circumferential inner wall of the first tunnel section T1. This helps guide and support the drill unit 10, thereby also improving the overall operational stability of the drill bit assembly 100. Optionally, the third cutting surface 12c is also provided with a plurality of cutting teeth.

[0101] It should be noted that the first cutting surface 12a, the second cutting surface 12b and the third cutting surface 12c are not limited to being planes or curved surfaces, or may be configured as a composite shape of planes and curved surfaces to accommodate different hole expansion requirements.

[0102] In some embodiments, as Figure 14 and Figure 15 As shown, a chip groove 121 is provided on one side of the cutting blade 12 close to the base 11. Thus, rock chips generated during the process of the drill unit 10 cutting the rock wall can be discharged outside the drill unit 10 through the chip groove 121 and further discharged through the second channel section T2.

[0103] There are multiple options for the specific structural form of the chip removal groove 121.

[0104] As some implementations, such as Figure 15 As shown, the chip groove 121 is a sawtooth groove.

[0105] In some embodiments, the drill unit 10 further includes a driving mechanism disposed between the base 11 and the cutting blade 12 to drive the cutting blade 12 to move relative to the base 11 and switch from the first position to the second position.

[0106] The drive mechanism is used to realize the switching of the cutting blade 12 between the first position (open / working position) and the second position (retracted / passing position), and its specific implementation forms can be various.

[0107] In some implementations, the drive mechanism includes a pressure piston assembly, wherein the piston body is disposed within a chamber provided within or on the surface of the base 11, and the piston rod is operably connected to the cutting blade 12. When pressurized fluid (e.g., water or mud) is input into the piston body, the extension or retraction of the piston rod drives the cutting blade 12 to move, thereby completing the switching from the first position to the second position.

[0108] As other implementation methods, the driving mechanism may include driving components such as an electric push rod or a motor, which is also fixed on the base 11, and the push rod / mover end is connected to the cutting blade 12, which receives control signals and electricity wirelessly to control the adjustment of the position of the cutting blade 12.

[0109] In some embodiments, reference Figure 4 As shown, the outer periphery of the base 11 is provided with a raised portion 111, and the cutting blade 12 is hingedly connected to the raised portion 111, with the hinge axis perpendicular to the rotation axis 1a. A receiving hole 112 is provided in the radial middle portion of the base 11, extending in the direction of the rotation axis 1a. The receiving hole 112 has a first end M near the working direction of the drill bit assembly 100 and a second end N away from the working direction.

[0110] As some implementations, such as Figure 6 As shown, the drill unit 10 further includes a rotation pin 19, a first hinge hole is provided on the raised portion 111 to cooperate with the rotation pin 19, and a second hinge hole is provided on the cutting blade 12 to cooperate with the rotation pin 19. The rotation pin 19 is rotatably inserted into the first hinge hole and the second hinge hole, so that the cutting blade 12 can rotate relative to the rotation pin 19, thereby achieving rotation relative to the raised portion 111.

[0111] As some implementations, the raised portion 111 may be provided in the form of an ear plate. Figure 4 、 Figure 5 and Figure 6As shown, two lug plates can be configured for each cutting blade 12. A first hinge hole is provided on each lug plate. The cutting blade 12 is arranged between the two lug plates, with the second hinge hole provided thereon coaxially aligned with the first hinge hole on the lug plate. A rotation pin 19 is rotatably inserted into the first and second hinge holes, thereby enabling the cutting blade 12 to rotate relative to the two lug plates.

[0112] Further references Figure 6 、 Figure 7 and Figure 9 A first through hole 112a is provided on the wall of the receiving hole 112. In the direction of the rotation axis 1a, the first through hole 112a is located between the protrusion 111 and the second end N of the receiving hole. The drive mechanism includes a piston 13 and a first push rod 14. The piston 13 is slidably disposed within the receiving hole 112. The piston 13 is provided with a first guide surface 13a. The radial distance between the first guide surface 13a and the rotation axis 1a varies along the direction of the rotation axis 1a. The first push rod 14 is inserted into the first through hole 112a, and one end of the first push rod 14 located radially outside the receiving hole 112 abuts against the cutting blade 12, while the other end abuts against the first guide surface 13a.

[0113] The piston 13 is configured to slide along the rotation axis 1 a to push the first push rod 14 to move along the first through hole 112 a , thereby pushing the cutting blade 12 to rotate around the protrusion 111 to switch from the first position to the second position.

[0114] During the sliding process of the piston 13 along the rotation axis 1a, since its first guide surface 13a is in contact with the end of the first push rod 14 and the radial distance between the first guide surface 13a and the rotation axis 1a changes, the axial movement of the piston 13 along the accommodating hole 112 is converted into the axial movement of the first push rod 14 along the first through hole 112a. Figure 7 and Figure 9 As shown in the figure, the first push rod 14 located on the right side in the first position moves to the right along the axial direction of the first through hole 112a under the direct push of the first guide surface 13a during the process of the piston 13 moving downward along the rotation axis 1a (i.e., toward the second end N of the receiving hole), thereby pushing the cutting blade 12 to rotate around the protrusion 111. Then, the cutting blade 12 is switched to the first push rod 14. Figure 13 and Figure 17 The second position is shown.

[0115] In some embodiments, as Figure 6 、 Figure 7 and Figure 13As shown, a first guide groove 131 is provided on the outer periphery of the piston 13, the first push rod 14 rests against the first guide groove 131, and a first guide surface 13a is formed at the bottom of the first guide groove 131. In the direction approaching from the first end M of the accommodating hole to the second end N of the accommodating hole, the radial distance between the first guide surface 13a and the rotation axis 1a gradually decreases, that is, the radial distance between the bottom of the first guide groove 131 and the rotation axis 1a gradually decreases.

[0116] The first guide groove 131 can provide a limit for the movement of the first push rod 14, so that the end of the first push rod 14 resting in the groove is always constrained to move in the groove, preventing the first push rod 14 from generating circumferential displacement or twisting during the movement and affecting the retraction process of the cutting knife 12, thereby ensuring that the cutting knife 12 can smoothly switch from the first position to the second position.

[0117] In some embodiments, reference Figure 6 As shown, the first guide groove 131 has a first guide groove first end 1311 close to the second end N of the receiving hole and a first guide groove second end 1312 close to the first end M of the receiving hole. Based on the above configuration, the groove depth at the first guide groove first end 1311 is greater than the groove depth at the first guide groove second end 1312. Figure 6 、 Figure 7 and Figure 13 As shown, when the cutting blade 12 is in the first position, the first push rod 14 abuts against the first end 1311 of the first guide groove, and when the cutting blade 12 is in the second position, the first push rod 14 abuts against the second end 1312 of the first guide groove. Thus, the first end 1311 of the first guide groove and the second end 1312 of the first guide groove can provide axial limitation for the first push rod 14 in the piston 13, so that the first push rod 14 maintains its own position stability when the cutting blade 12 is in the first position and the second position, respectively, thereby also helping to improve the overall structural stability of the drill unit 10.

[0118] In some embodiments, as Figure 7 、 Figure 12 and Figure 13 As shown, the wall of the receiving hole 112 is further provided with a second through hole 112b. In the direction of the rotation axis 1a, the second through hole 112b is located between the protrusion 111 and the first end M of the receiving hole. The drive mechanism also includes a second push rod 16. The second push rod 16 is disposed in the second through hole 112b. One end of the second push rod 16, located radially outward from the receiving hole 112, abuts against the cutting blade 12, and the other end abuts against the outer surface of the piston 13.

[0119] By providing a second push rod 16 that passes through the second through hole 112b, the second push rod 16 can provide support for the cutter 12 and maintain the position stability of the cutter 12. For example, when the cutter 12 is in the first position, especially when the drill unit 10 is performing a cutting operation, the second push rod 16 abuts against the piston 13. During the cutting operation, the piston 13 remains stationary in the axial direction relative to the receiving hole 112, and the radial position of the second push rod 16 relative to the receiving hole 112 can also remain stationary, thereby maintaining the cutter 12 in the first position. This arrangement allows the cutter 12 to remain in the open state in the first position even when subjected to a reaction force during the rock wall cutting process, thereby preventing the cutting process from being affected and ensuring the operational reliability of the drill unit 10.

[0120] In addition, during the process of the cutting knife 12 rotating around the protrusion 111 and switching from the first position to the second position, the second push rod 16 moves axially along the second through hole 112b under the push of the cutting knife 12, and the cutting knife 12 always keeps rotating against the second push rod 16, that is, the second push rod 16 can also provide a certain support for the cutting knife 12 during its rotation, which helps to improve the movement stability of the cutting knife 12 during the switching process from the first position to the second position.

[0121] Further references Figure 6 In some embodiments, the piston 13 further comprises a second guide surface 13b. The radial distance between the second guide surface 13b and the rotation axis 1a varies along the rotation axis 1a. The second push rod 16 is disposed within the second through hole 112b. One end of the second push rod 16, located radially outward from the receiving hole 112, abuts the cutting blade 12, while the other end abuts the second guide surface 13b.

[0122] As the piston 13 slides downward along the direction of the rotation axis 1a (i.e., toward the second end N of the accommodating hole), it pushes the cutting blade 12 to rotate around the protrusion 111, so that the second push rod 16 is pushed by the cutting blade 12 to move axially along the second through hole 112b and slide along the second guide surface 13b.

[0123] In some embodiments, as Figure 7 As shown, the extending direction of the first through hole 112a and / or the second through hole 112b is perpendicular to the direction of the rotation axis 1a.

[0124] In some examples, the extension direction of the first through hole 112 a is perpendicular to the direction of the rotation axis 1 a , so that when the piston 13 slides along the direction of the rotation axis 1 a , the first push rod 14 translates radially along the accommodating hole 112 .

[0125] In some examples, the extension direction of the second through hole 112 b is perpendicular to the direction of the rotation axis 1 a , so that when the piston 13 slides along the direction of the rotation axis 1 a , the second push rod 16 translates radially along the accommodating hole 112 .

[0126] In some embodiments, as Figure 6 、 Figure 7 and Figure 13 As shown, a second guide groove 132 is provided on the outer periphery of the piston 13, the second push rod 16 rests in the second guide groove 132, and a second guide surface 13b is formed at the bottom of the second guide groove 132. In the direction from the first end M of the accommodating hole to the second end N of the accommodating hole, the radial distance between the second guide surface 13b and the rotation axis 1a gradually increases, that is, the radial distance between the bottom of the second guide groove 132 and the rotation axis 1a gradually increases.

[0127] The second guide groove 132 can provide a limit for the movement of the second push rod 16, so that the end of the second push rod 16 resting in the groove is always constrained to move in the groove, preventing the second push rod 16 from generating circumferential displacement or twisting during the movement and affecting the retraction process of the cutting knife 12, thereby ensuring that the cutting knife 12 can smoothly switch from the first position to the second position.

[0128] In some embodiments, reference Figure 6 As shown, the second guide groove 132 has a second guide groove first end 1321 close to the first end M of the receiving hole and a second guide groove second end 1322 close to the second end N of the receiving hole. Based on the above configuration, the groove depth at the second guide groove first end 1321 is greater than the groove depth at the second guide groove second end 1322. Figure 6 、 Figure 7 and Figure 13 As shown, when the cutting blade 12 is in the first position, the second push rod 16 abuts against the second guide groove second end 1322, and when the cutting blade 12 is in the second position, the second push rod 16 abuts against the second guide groove first end 1321. Thus, the second guide groove first end 1321 and the second guide groove second end 1322 can provide axial limitation for the second push rod 16 in the piston 13, so that the second push rod 16 maintains its own position stability when the cutting blade 12 is in the first position and the second position, respectively, thereby also helping to improve the overall structural stability of the drill unit 10.

[0129] According to the embodiment of the present invention, the first end 1311 of the first guide groove and the second end 1312 of the first guide groove can provide axial positioning of the first push rod 14 with respect to the piston 13, and the first end 1321 of the second guide groove and the second end 1322 of the second guide groove can provide axial positioning of the second push rod 16 with respect to the piston 13. Thus, when the cutting blade 12 is in the first position and the second position, the axial position of the piston 13 within the receiving hole 112 can be limited by the matching relationship between the first guide groove and the first push rod 14, and the matching relationship between the second guide groove and the second push rod 16, and the axial travel range of the piston 13 within the receiving hole 112 can also be limited. In this way, the second cutting blade 12 can maintain its own position stability when it is in the first position and the second position, and it also helps to avoid the risk of the piston 13 slipping out of the hole when sliding.

[0130] According to the embodiment of the present invention, there are multiple options for the specific structural parameters of the piston 13.

[0131] Optionally, the first guide groove 131 and the second guide groove 132 are symmetrical about a radial center section of the piston 13. The radial center section is a section located in the axial middle of the piston 13 and is perpendicular to the axis of the piston 13.

[0132] Optional, such as Figure 12 As shown, the included angle β1 between the first guide groove 131 and the axis of the piston 13 is less than 45 degrees, and the included angle β2 between the second guide groove 132 and the axis of the piston 13 is less than 45 degrees.

[0133] Optionally, the number of the first guide grooves 131 and their circumferential positions relative to the piston 13 may be set to correspond to the number of the cutting blades 12 and their circumferential positions relative to the base 11 .

[0134] Optionally, the number of the second guide grooves 132 and their circumferential positions relative to the piston 13 may also be set to correspond to the number of the cutting blades 12 and their circumferential positions relative to the base 11 .

[0135] In some embodiments, reference Figure 8 、 Figure 9 、 Figure 16 and Figure 17 As shown, a limiting protrusion 1121 is provided on the inner wall of the accommodating hole 112 near the second end N of the accommodating hole. The driving mechanism further includes a first spring 15 , which is provided between the piston 13 and the limiting protrusion 1121 .

[0136] The limiting protrusion 1121 is used to provide axial support to the first spring 15. As some implementations, the limiting protrusion 1121 can be as follows Figure 8 and Figure 9As shown in FIG, a radially protruding structure is provided that is integrally formed with the receiving hole 112. As another implementation, instead of providing the limiting protrusion 1121 on the receiving hole 112, a detachable blocking structure can be provided to provide axial support for the first spring 15, such as a nut detachably connected to the second end N of the receiving hole.

[0137] The first spring 15 provides support for the piston 13. When the cutting blade 12 is in the first position, the first spring 15 exerts a certain preload, generating an upward spring force on the piston 13 (i.e., a force pushing the piston 13 toward the first end M of the receiving hole), thereby maintaining the piston 13 in the first axial position capable of maintaining the cutting blade 12 in the first position. When the piston 13 is in this first axial position, the first push rod 14 retracts relative to the base 11, the second push rod 16 extends relative to the base 11, and the cutting blade 12 is in the first position, ensuring that the drill unit 10 is in an operating state capable of cutting the rock wall and achieving hole expansion. The first push rod 14 engages with the first guide groove 131 of the piston 13 (abutting against the first end 1311 of the first guide groove), and the second push rod 16 engages with the second guide groove 132 of the piston 13 (abutting against the second end 1322 of the second guide groove), further stabilizing the piston 13 in the first axial position.

[0138] Furthermore, when the piston 13 is subjected to a force pushing it toward the second end N of the receiving hole, the piston 13 slides along the direction of the rotational axis 1a toward the second end N of the receiving hole, thereby causing the first push rod 14 to extend relative to the base 11 and the second push rod 16 to retract relative to the base 11, thereby switching the cutting blade 12 to the second position. Here, the piston 13 moves to the second axial position that maintains the cutting blade 12 in the second position. Here, the first push rod 14 engages with the first guide groove 131 of the piston 13 (abutting against the second end 1312 of the first guide groove), and the second push rod 16 engages with the second guide groove 132 of the piston 13 (abutting against the first end 1321 of the second guide groove), further stabilizing the piston 13 in the first axial position.

[0139] In some embodiments, the drill head unit 10 further includes a first limiting structure, which is configured to position the piston 13 axially relative to the receiving hole 112 after the cutter 12 switches from the first position to the second position. With this arrangement, the cutter 12 can maintain a stable position after switching to the second position, thereby allowing the drill head unit 10 to maintain the non-operating state in which the cutter 12 is retracted, facilitating further movement into the first tunnel section T1. Furthermore, during subsequent operations, the cutter 12 can be kept retracted without affecting the normal operation of other drill head units 10 that are in an operating state.

[0140] In some embodiments, as Figure 9 and Figure 17 As shown, a first position-limiting recess 133 is provided on the outer circumferential surface of the piston 13, and a first position-limiting hole 1122 for accommodating the first position-limiting structure is provided on the wall of the receiving hole 112. When the piston 13 is in the axial position where the cutting blade 12 is in the first position, the first position-limiting structure is configured such that the end of the first position-limiting structure proximate to the piston 13 is completely embedded in the axial interior of the first position-limiting hole 1122. When the piston 13 is in the axial position where the cutting blade 12 is in the second position, the first position-limiting structure is configured such that the end of the first position-limiting structure proximate to the piston 13 protrudes from the first position-limiting hole 1122 and is embedded in the inner first position-limiting recess 133, thereby positioning the piston 13 axially relative to the receiving hole 112.

[0141] As some implementations, such as Figure 9 As shown, the first limiting recess 133 is arranged on the outer peripheral surface of the piston 13 in a staggered manner with respect to the first guide groove 131 .

[0142] In some embodiments, Figure 9 When the piston 13 shown is in an axial position that places the cutting blade 12 in the first position, the first limiting recess 133 and the first limiting hole 1122 are not aligned, and the end of the first limiting structure close to the piston 13 is completely embedded in the axial interior of the first limiting hole 1122. In some implementations, the first limiting structure includes a first limiting stud 103, a first limiting spring 104, and a first limiting block 105. The first limiting stud 103 is fixedly connected to the end of the first limiting hole 1122 away from the piston 13, for example, by threading, and the first limiting spring 104 is disposed between the first limiting stud 103 and the first limiting block 105. When the first limiting recess 133 and the first limiting hole 1122 are not aligned, the first limiting block 105 abuts against the outer peripheral surface of the piston 13, and the first limiting spring 104 is in a compressed state. When the piston 13 moves to the axial position where the first limiting recess 133 and the first limiting hole 1122 are aligned, i.e., the cutting blade 12 is in the second position, the first limiting block 105 is inserted into the first limiting recess 133 under the elastic force of the first limiting spring 104 and is pressed against the first limiting recess 133, so that the first limiting block 105 and the first limiting recess 133 can be mutually engaged. Based on this, the first limiting structure limits the axial position of the piston 13, thereby preventing the piston 13 from moving toward the first end M of the accommodating hole under the elastic force of the first spring 15, and thus preventing the cutting blade 12 from returning to the first position.

[0143] In some implementations, the first stopper 105 is configured to release its engagement with the first stopper recess 133, thereby enabling the first stopper structure to be removed from the drill head unit 10, and further enabling the piston 13 to be removed from the receiving hole 112. Thus, after the drill head assembly 100 completes each reaming operation, the piston 13 can be easily removed, and further, the disassembly and maintenance of other components that cooperate with the piston 13 can be facilitated.

[0144] In some specific examples, the first limiting block 105 is configured to engage with the first limiting recess 133 within a preset angular range, for example, the first limiting block 105 is configured to have a non-circumferential engaging structure. Thus, by rotating the first limiting structure, in particular, by rotating the first limiting stud 103 to drive the first limiting block 105 relative to the first limiting recess 133 to a position outside the engaging angular range of the engaging structure, the first limiting block 105 can be released from the first limiting recess 133, and the first limiting structure can be further removed.

[0145] In other specific examples, such as Figure 17 As shown, the end of the first position-limiting recess 133 near the first end M of the receiving hole is configured to have an arcuate guide surface. Therefore, when the first position-limiting structure needs to be removed, the piston 13 can be further pushed toward the second end N of the receiving hole, and the first position-limiting block 105 can be squeezed by the arcuate guide surface, thereby pushing the first position-limiting block 105 back axially inside the first position-limiting hole 1122, allowing further removal of the piston 13.

[0146] According to embodiments of the present invention, there are various options for pushing the piston 13 to slide in the receiving hole 112. In some implementations, fluid can be injected into the receiving hole 112 to push the piston 13 to move, particularly to overcome the elastic force of the first spring 15 and move toward the second end N of the receiving hole.

[0147] In some embodiments, the receiving hole 112 is continuous along the direction of the rotation axis 1a. The piston 13 is sealed with the hole wall of the receiving hole 112 in the circumferential direction and is provided with a flow channel running through it. Figure 12 and Figure 17As shown, the flow channel includes a flow channel inlet m adjacent to the first end M of the receiving hole and in fluid communication therewith, and a flow channel outlet n adjacent to the second end N of the receiving hole and in fluid communication therewith. The drill unit 10 also includes a pressure relief assembly, which is disposed in the flow channel and has a closed state and an open state. The pressure relief assembly is configured to: be in a closed state when the fluid pressure at the flow channel inlet m is less than or equal to a preset pressure, so as to block the flow channel and thereby cut off the fluid communication between the first end M of the receiving hole and the second end N of the receiving hole; and, switch to an open state when the fluid pressure at the flow channel inlet m is greater than a preset pressure, so as to release the blockage of the flow channel and thereby enable the first end M of the receiving hole and the second end N of the receiving hole to be in fluid communication.

[0148] As some implementations, a seal is further provided between the piston 13 and the wall of the receiving hole 112 to ensure the sealing reliability between the piston 13 and the receiving hole 112 in the circumferential direction. The specific form and location of the seal can be adjusted according to the specific structure and shape of the piston 13. As an example, refer to Figure 6 As shown, a sealing ring 101 is provided on the radial outer side of the end portion of the piston 13 close to the first end M of the accommodating hole and on the radial outer side of the axial middle portion of the piston 13, thereby achieving circumferential sealing at these two positions.

[0149] Through the arrangement in the above embodiment, the flow of fluid between the multiple drill head units 10 , especially the flow of fluid between two adjacent drill head units 10 , can be controlled.

[0150] by Figure 2 Taking the adjacent drill units 10-1 and 10-2 as an example, when the pressure relief assembly in drill unit 10-1 is in the closed state, if a fluid with a certain pressure is injected into the first end M of its receiving hole, and if the fluid flows into the flow channel inlet m and further flows through the flow channel to the position of the pressure relief assembly, and the fluid pressure is less than or equal to the preset pressure, the pressure relief assembly will remain closed, and the fluid cannot flow from drill unit 10-1 to the drill unit 10-2 at the next level. If the fluid flows into the flow channel inlet m and further flows through the flow channel to the position of the pressure relief assembly, and the fluid pressure is greater than the preset pressure, the pressure relief assembly in drill unit 10-1 switches from the closed state to the open state under the action of the fluid, thereby unblocking the flow channel in piston 13 and allowing the fluid to flow further to the drill unit 10-2 at the next level. In other words, by controlling the pressure of the fluid injected into the first end M of the receiving hole, the open and closed state of the pressure relief assembly can be controlled.

[0151] Here, there are multiple options for the arrangement of the pressure relief component in the flow channel and the structure and form of the pressure relief component itself, as long as the pressure relief component can block and release the flow channel in response to changes in fluid pressure.

[0152] In some embodiments, as Figure 9 As shown, the flow channel includes a first flow channel section 1301 and a second flow channel section 1302 that are interconnected. The first flow channel section 1301 extends along the direction of the rotation axis 1a and is connected to the flow channel inlet m. The second flow channel section 1302 is perpendicular to the first flow channel section 1301 and is connected to the flow channel outlet n. As some implementations, such as Figure 12 and Figure 17 As shown, the inlet of the first flow channel section 1301 constitutes the flow channel inlet m, and the outlet of the second flow channel section 1302 constitutes the flow channel outlet n.

[0153] Further, such as Figure 8 As shown, the pressure relief assembly includes a valve core 17 and a second spring 18 disposed within the first flow channel segment 1301. The second spring 18 is disposed between the valve core 17 and an axial end portion of the first flow channel segment 1301, adjacent to the second end N of the receiving hole. The valve core 17 is configured to: when the pressure relief assembly is closed, block the connection between the first flow channel segment 1301 and the second flow channel segment 1302; and, when the pressure of the fluid within the first flow channel segment 1301 exceeds a predetermined pressure, the valve core 17, driven by the fluid, compresses the second spring 18 and moves toward the axial end portion of the first flow channel segment 1301, thereby releasing the blockage of the connection.

[0154] Based on this, if a fluid with a certain pressure is injected into the first end M of the receiving hole, if the fluid flows into the flow channel inlet m and further flows through the flow channel to the position of the pressure relief component, the pressure of the fluid is less than or equal to the preset pressure. At this time, the pressure generated by the fluid on the valve core 17 is less than or equal to the preload force of the second spring 18. The pressure relief component will still remain closed, and the fluid cannot flow from the drill unit 10-1 to the drill unit 10-2 of the next level. If the fluid flows into the flow channel inlet m and further flows through the flow channel to the position of the pressure relief component, the fluid pressure is greater than the preset pressure. At this time, the pressure generated by the fluid on the valve core 17 is greater than the preload force of the second spring 18. Then, under the action of the fluid, the pressure relief component in the drill unit 10-1 switches from the closed state to the open state.

[0155] In some embodiments, as Figure 17 As shown, a mating portion 13011 is provided at the connection between the first flow channel section 1301 and the second flow channel section 1302. When the pressure relief assembly is in the closed state, the mating portion 13011 abuts and clings to the end of the valve core 17 away from the second spring 18, thereby blocking the flow of fluid between the first flow channel section 1301 and the second flow channel section 1302.

[0156] As some implementation methods, the shape of the matching part 13011 is set to correspond to the shape of the end of the valve core 17 away from the second spring 18, so that the matching part 13011 can fit tightly with the valve core 17 to achieve the blocking of the connection between the first flow channel section 1301 and the second flow channel section 1302.

[0157] Further, such as Figure 18 As shown, when the valve core 17 moves to a position to release the blockage of the connection point under the push of the fluid, the mating portion 13011 disengages from the valve core 17, so that the fluid can flow from the first flow channel section 1301 into the second flow channel section 1302, and then flow to the second end N of the accommodating hole, and further flow into the first end M of the accommodating hole of the next drill unit 10.

[0158] In some embodiments, the drill head unit 10 further includes a second position-limiting structure, which is configured to position the valve core 17 axially relative to the first flow channel segment 1301 after the valve core 17 moves from a position blocking the connection between the first flow channel segment 1301 and the second flow channel segment 1302 to a position where the connection is unblocked. With this arrangement, the valve core 17 can maintain a stable axial position relative to the first flow channel segment 1301 after moving to the position where the connection is unblocked, thereby maintaining the flow channel in a fluid-connected state and facilitating smooth flow of fluid from a first-stage drill head unit 10 to a next-stage drill head unit 10.

[0159] In some embodiments, as Figure 8 and Figure 16 As shown, a second position-limiting recess 171 is provided on the outer periphery of the valve core 17, and a second position-limiting hole 134 is provided on the piston 13, extending through the first flow channel section 1301 and accommodating the second position-limiting structure. When the valve core 17 is in a position blocking the connection between the first flow channel section 1301 and the second flow channel section 1302, the second position-limiting structure is configured such that the end of the second position-limiting structure proximate the valve core 17 is completely embedded axially within the second position-limiting hole 134. When the valve core 17 moves to a position that releases the blockage of the connection, the second position-limiting structure is configured such that the end of the second position-limiting structure proximate the valve core 17 protrudes from the second position-limiting hole 134 and is embedded within the second position-limiting recess 171, thereby positioning the valve core 17 axially relative to the first flow channel section 1301.

[0160] As some implementation methods, when the valve core 17 is in a position to block the connection between the first flow channel section 1301 and the second flow channel section 1302, the second limiting recess 171 and the second limiting hole 134 are not aligned, and the end of the second limiting structure close to the valve core 17 is completely embedded in the second limiting hole 134.

[0161] In some examples, the second limiting structure includes a second limiting stud 106, a second limiting spring 107, and a second limiting block 108. The second limiting stud 106 is fixedly connected to the end of the second limiting hole 134 away from the valve core 17, for example, by a threaded connection, and the second limiting spring 107 is disposed between the second limiting stud 106 and the second limiting block 108. When the second limiting recess 171 and the second limiting hole 134 are not aligned, the second limiting block 108 abuts against the outer periphery of the valve core 17, and the second limiting spring 107 is in a compressed state. When the valve core 17 moves until the second limiting recess 171 and the second limiting hole 134 are aligned, the second limiting block 108 is pushed by the elastic force of the second limiting spring 107 to be stuck in the second limiting recess 171 and tightened against the second limiting recess 171.

[0162] In some embodiments, the first flow channel segment 1301 extends through the piston 13 along the rotational axis 1a. The pressure relief assembly further includes a pressure relief stud 102 connected to the axial end of the first flow channel segment 1301 near the second end N of the receiving hole. The pressure relief stud 102 is used to support the second spring 18. For example, the pressure relief stud 102 is threadedly connected to the axial end of the first flow channel segment 1301 near the second end N of the receiving hole.

[0163] In some embodiments, when the cutting blade 12 is in the first position, the first spring 15 is compressed and has a first preload force, and the second spring 18 is compressed and has a second preload force.

[0164] As some implementations, in the same drill head unit 10, the first preload force of the first spring 15 is less than the second preload force of the second spring 18; and, along the direction of the rotation axis 1a, the second preload force of the second spring 18 of the drill head unit 10 close to the working direction of the drill head assembly 100 is less than the second preload force of the second spring 18 of the drill head unit 100 away from the working direction of the drill head assembly 100.

[0165] Here, Figure 2 Taking the adjacent drill unit 10-1, drill unit 10-2 and drill unit 10-3 as an example, the setting principle of the preload force of each spring is explained.

[0166] For example, during operation of the drill head assembly 100, if the drill head unit 10-1 in the working position experiences wear and its cutting blade 12 needs to be retracted, a fluid having a first pressure can be introduced into the first end M of the receiving hole of the current drill head unit 10-1. This fluid having the first pressure can generate a first pressure on the piston 13 near the first end M of the receiving hole when it flows to the position where the piston 13 is located, and a second pressure on the valve core 17 when it flows to the position where the pressure relief assembly is located. The magnitude of the first pressure of the fluid can be set so that the generated first pressure is greater than the first preload force of the first spring 15 of the current drill head unit 10-1, but the generated second pressure is less than the second preload force of the second spring 18. Consequently, the piston 13 of the current drill head unit 10-1, driven by the first pressure of the fluid, can compress the first spring 15, thereby moving toward the second end N of the receiving hole and pushing the cutting blade 12 from the first position to the second position, thereby retracting the cutting blade 12 of the current drill head unit 10-1.

[0167] At this time, because the second pressure is less than the second preload force of the second spring 18 of the current drill unit 10-1, the pressure relief assembly of the current drill unit 10-1 remains closed, and fluid cannot pass through the fluid channel, and thus cannot flow into the next-stage drill unit 10-2 connected to the current drill unit 10-1, thereby avoiding affecting the open state of the cutting blade 12 of the next-stage drill unit 10-2. The drill unit 10-2 can now move to the working position and take over the drilling operation from the drill unit 10-1.

[0168] Furthermore, if the drill unit 10-2 wears out during subsequent operations and the cutting blade 12 needs to be retracted, a fluid with a second pressure can be input into the first end M of the receiving hole of the drill unit 10-1. The fluid with the second pressure can generate a second pressure on the valve core 17 when it flows to the position of the pressure relief component of the drill unit 10-1. The second pressure is greater than the second preload force of the second spring 18 of the drill unit 10-1, so that the pressure relief component of the drill unit 10-1 is switched to the open state, and the fluid can flow through the fluid channel in the drill unit 10-1 to the first end M of the receiving hole of the drill unit 10-2.

[0169] Here, because the second preload force of the second spring 18 of drill unit 10-2 is greater than the second preload force of the second spring 18 of drill unit 10-1, and the second preload force of the second spring 18 of drill unit 10-2 is also greater than the first preload force of the first spring 15 of drill unit 10-2, the magnitude of the second pressure of the fluid can be set so that the second pressure generated by the fluid at the pressure relief assembly of drill unit 10-1 is greater than the first preload force of the first spring 15 of drill unit 10-2 and less than the second preload force of the second spring 18 of drill unit 10-2. Consequently, the fluid can flow smoothly from drill unit 10-1 to drill unit 10-2, causing the cutting blade 12 of drill unit 10-2 to switch from the first position to the second position, achieving retraction. At the same time, the pressure relief assembly of drill unit 10-2 can remain closed, preventing fluid from flowing into the lower-level drill unit 10-3, and thus the open state of the cutting blade 12 of the lower-level drill unit 10-3 is not affected by the fluid. The drill unit 10-3 can now be moved to the working position to take over the drill unit 10-2 to perform the hole expansion operation.

[0170] In actual applications, fluid is usually input into the receiving hole 112 of the first-stage drill unit 10 to achieve fluid supply to the drill unit 10 of that stage, and the fluid is further made to flow to the subsequent stage along the multiple stages of drill units 10 connected in series, so as to supply fluid to the receiving holes 112 of the subsequent one or more stages of drill units 10.

[0171] Based on this, in order to facilitate the control of the pressure of the fluid input to the drill bit assembly 100 during operation, a starting pressure P can be configured for each stage of the drill bit unit 10 to enable the retraction of its cutting blade 12 without causing the retraction of the cutting blade 12 of the next stage of the drill bit unit 10. The starting pressure P refers to the pressure of the fluid at the first end M of the receiving hole of the first stage of the drill bit unit 10.

[0172] Here, based on Figure 2 The embodiment shown illustrates the configuration of the starting pressure P of a total of five levels of drill head units 10. The starting pressure of the fluid corresponding to each level of drill head unit 10 is P1, P2, P3, P4 and P5 respectively.

[0173] In this embodiment, each drill unit 10 includes a first stopper structure and a second stopper structure. Thus, after the piston 13 of each drill unit 10 moves to the axial position where the cutting blade 12 is retracted, the piston 13 is held in this axial position by the first stopper structure, thereby maintaining the retracted cutting blade 12. Similarly, after the pressure relief assembly of each drill unit 10 is opened, the pressure relief assembly is held in the open position by the second stopper structure, thereby maintaining the unobstructed flow path within the piston 13.

[0174] Based on the above settings,

[0175] To retract the cutting blade 12 of the drill unit 10 - 1 , a fluid with a pressure of P1 is input into the first end M of the receiving hole thereof. The fluid is configured to be able to push the piston 13 thereof to move but not to open the pressure relief assembly thereof.

[0176] To further retract the cutter 12 of the drill unit 10-2, a fluid with a pressure of P2 is input into the first end M of the receiving hole of the drill unit 10-1. The fluid is configured to open the pressure relief component of the drill unit 10-1 and to push the piston 13 of the drill unit 10-2 to move, but the fluid cannot open the pressure relief component of the drill unit 10-2.

[0177] To further retract the cutter 12 of the drill unit 10-3, a fluid with a pressure of P3 is input into the first end M of the receiving hole of the drill unit 10-1. The fluid is configured to open the pressure relief component of the drill unit 10-2 and to push the piston 13 of the drill unit 10-3 to move, but the fluid cannot open the pressure relief component of the drill unit 10-3.

[0178] If the cutting blade 12 of the drill unit 10-4 is to be further retracted, a fluid with a pressure of P4 is input into the first end M of the receiving hole of the drill unit 10-1. The fluid is configured to open the pressure relief component of the drill unit 10-3 and to push the piston 13 of the drill unit 10-4 to move, but the fluid cannot open the pressure relief component of the drill unit 10-4.

[0179] If the cutting blade 12 of the drill unit 10-5 is to be further retracted, a fluid with a pressure of P5 is input into the first end M of the accommodating hole of the drill unit 10-1. The fluid is configured to be able to open the pressure relief component of the drill unit 10-4 and to push the piston 13 of the drill unit 10-5 to move, but the fluid cannot open the pressure relief component of the drill unit 10-5.

[0180] Based on the above description, it is easy to know that P1 <P2<P3<P4<P5。

[0181] Accordingly, it can be understood that in a multi-stage drill unit 10, the preload force of the first spring 15 of each stage drill unit 10 can be set to be equal, but the preload force of the second spring 18 of the drill unit 10 with a smaller stage should be set to be smaller than the preload force of the second spring 18 of the drill unit 10 with a larger stage.

[0182] Based on the above-mentioned drill bit assembly 100, the present invention also provides a hole enlarging device. Figure 1 As shown, the reaming device includes a drill bit assembly 100 , a drill rod 200 , a drilling rig 300 , a detection device 400 and a controller 500 .

[0183] like Figure 1 As shown, the drill rod 200 is connected to the drill bit assembly 100. The drilling rig 300 is connected to the end of the drill rod 200 away from the drill bit assembly 100. The drilling rig 300 is configured to drive the drill rod 200 to move along the working direction, thereby driving the drill bit assembly 100 to move along the working direction to expand the working tunnel T.

[0184] In some embodiments, as Figure 1 As shown, the drilling rig 300 includes a rotary motor 310, a push-pull motor 320, and a base 330. The rotary motor 310 and the push-pull motor 320 are mounted on the base 330 so that the rotary motor 310, the push-pull motor 320, and the base 330 can form a whole that can move together. The rotary motor 310 is configured to drive the drill rod 200 to rotate to drive the drill bit assembly 100 to rotate. The push-pull motor 320 is configured to pull the drill rod 200 to move it along the working direction, that is, along the working direction. Figure 1 The extension direction of the middle working channel T moves obliquely upward to the right.

[0185] Further, such as Figure 1 As shown, in some embodiments, the reaming device further includes a frame 700, and the drilling rig 300 is movably mounted on the frame 700. As some implementations, the base 330 of the drilling rig 300 is slidably mounted on the guide rail 710 of the frame 700. Optionally, the guide rail 710 is tilted relative to the ground where the frame 700 is located, and its tilt angle is the same as the tilt angle of the working tunnel T relative to the ground. When the push-pull motor 320 pulls the drill rod 200 to move along the working direction V+ shown in the figure, the drilling rig 300 itself slides along the guide rail 710 toward the working tunnel T. As an example, the output end of the push-pull motor 320 is a gear structure, and the gear structure cooperates with the rack of the guide rail 710 to realize transmission.

[0186] In some embodiments, the detection device 400 includes a pressure sensor 410 and a rotation speed sensor 420. The pressure sensor 410 is configured to detect the operating pressure of the rotary motor 310, which corresponds to the output torque of the rotary motor 310. The rotation speed sensor 420 is configured to detect the rotation speed output by the rotary motor 310, that is, the corresponding rotation speed of the drill rod 200.

[0187] In some embodiments, the detection device 400 further includes a push-pull pressure sensor 430 and a displacement sensor 440. The push-pull pressure sensor 430 is configured to detect the operating pressure of the push-pull motor 320, which corresponds to the pulling force required by the push-pull motor 320 to move the drill rod 200. The displacement sensor 440 is configured to detect the push-pull speed output by the push-pull motor 320, i.e., the speed at which the drill rod 200 moves along the working tunnel T.

[0188] According to an embodiment of the present invention, the detection device 400 is configured to detect the operating status of at least the drill head unit 10 of the drill head assembly 100 that is in the working position.

[0189] As some implementation methods, the operating status of the drill unit 10 in the working position can be reflected by one or more of the parameters such as the working pressure of the above-mentioned rotary motor 310, the rotation speed output by the rotary motor 310, the working pressure of the push-pull motor 320, and the detection of the push-pull speed output by the push-pull motor 320.

[0190] For example, when one or more of the above parameters deviate from the preset values to a certain range, or exceed the normal range to a certain extent, it can be determined that the drill unit 10 in the working position is worn and in a failure state, and it is necessary to switch to the next-level drill unit 10 for operation.

[0191] Among them, the preset values of the relevant parameters or the values of the normal range of the relevant parameters can be set with reference to the operation requirements and operation experience, and will not be elaborated here.

[0192] According to an embodiment of the present invention, the controller 500 is configured to: receive a signal from the detection device 400; respond to a signal detected by the detection device 400 that the drill unit 10 in the working position is in a failure state, and control the cutter 12 of the drill unit 10 in the failure state to switch to the second position; and control the drilling rig 300 to drive the drill rod 200 to move along the working direction to pull the drill unit 10 in the failure state to move into the working channel T, and make the next drill unit 10 connected in series on the side of the drill unit 10 in the failure state away from the drilling rig 300 move to the working position.

[0193] In some implementations, the controller 500 receives signals (i.e., multiple detection results for the aforementioned related parameters) in real time from the detection device 400 and, based on the multiple detection results, determines whether one or more of the aforementioned related parameters deviate from a preset value by a certain range or exceed a normal range by a certain degree. If the drill head unit 100 in the working position is determined to be in a failed state, the controller 500 determines that the drill head unit 10 within the drill head assembly 100 needs to be replaced. The controller 500 then controls the position of the cutting blade 12 of the drill head unit 10 within the drill head assembly 100 and controls the drill rig 300 to pull the drill rod 200.

[0194] In some embodiments, the reaming device further includes a water pump 600. The water pump 600 is used to supply water or mud into the receiving hole 112 of the drill unit 10, so that the drill unit 10 can perform a position switching action of the corresponding cutting blade 12.

[0195] In some implementations, the drill rod 200 is hollow, its inner cavity communicating with the receiving hole 112 of the drill head unit 10. The fluid output end of the water pump 600 communicates with the inner cavity of the drill rod 200 to deliver water or slurry into the receiving hole 112 of the drill head unit 10. The water pump 600 includes a relief valve 610 and a flow sensor 620. The relief valve 610 controls the pressure of the water or slurry delivered by the water pump 600, while the flow sensor 620 controls the flow rate of the water or slurry delivered by the water pump 600.

[0196] Regarding how the drill bit unit 10 realizes the position switching of its cutting blade 12 under the action of fluid (for example, water or mud), and how the fluid is circulated between the multi-stage drill bit units 10, the content of the structural part of the drill bit unit 10 described above has been described in detail and will not be repeated here.

[0197] Specifically, in the process of the controller 500 controlling the drill unit 10 in the drill assembly 100 to switch the position of the cutting blade 12, the controller 500 controls the overflow valve 610 to adjust the pressure of the water or mud to a specified size, so that when the water or mud flows to a specific position such as the one described above (such as the position of the piston 13, the position of the valve core 17), it can form a first pressure required to meet the movement of the piston 13 or form a second pressure required to meet the movement of the valve core 17.

[0198] Here, the relief valve 610 can be defined as being able to adjust the output pressure of the water pump 600 to a first activation pressure P1. At this point, when the water or slurry output by the water pump 600 flows to the position where the piston 13 is located, it can generate a first pressure required to satisfy the movement of the piston 13, that is, it can activate the first spring 15 (that is, it is pushed by the piston 13 to achieve further compression). The relief valve 610 can also be defined as being able to adjust the output pressure of the water pump 600 to a second activation pressure P2. At this point, when the water or slurry output by the water pump 600 flows to the position where the valve core 17 of the pressure relief assembly is located, it can generate a second pressure required to satisfy the movement of the valve core 17, that is, it can activate the second spring 18 (that is, it is pushed by the valve core 17 to achieve further compression).

[0199] Specifically, in the process of the controller 500 controlling the drilling rig 300 to lift the drill rod 200, the controller 500 controls the action of the push-pull motor 320 to drive the drilling rig 300 as a whole to move relative to the guide rail 710, and at the same time realizes the lifting of the drill rod 200, so that the drill bit assembly 100 is lifted accordingly, thereby moving the failed drill bit unit 10 into the first working channel section T1, and the next-level drill bit unit 10 moves to the working position.

[0200] Next, an exemplary embodiment of replacing the drill bit unit during the reaming operation of the reaming device according to an embodiment of the present invention is described, especially the workflow of the controller 500. Figure 19 As shown, taking the controller 500 including the data acquisition module 510, the data analysis module 520 and the execution module 530 as an example, its control logic mainly includes the following steps:

[0201] Step 1: When the drill bit assembly 100 performs a hole enlarging operation, the data acquisition module 510 automatically collects various sensor signals from the detection device 400 and transmits each signal to the data analysis module 520 in real time.

[0202] Step 2: The data analysis module 520 analyzes each received signal. When the working pressure of the rotary motor 310 is greater than the first threshold, the working pressure of the push-pull motor 320 is greater than the second threshold, and the push-pull speed output by the push-pull motor 320 is less than the third threshold, an alarm is output to prompt that the drill unit 10 currently in the working position has failed and the next-level drill unit 10 needs to be replaced. The specific values of the first threshold, the second threshold and the third threshold can be set according to the actual working conditions.

[0203] Step 3: Obtain the initial position of the push-pull motor 320 on the guide rail 710 (for example, L0 = 0 mm) based on the information recorded by the displacement sensor 440 .

[0204] Step 4: The data analysis module 520 determines the level of the currently failed operating unit 10. If the currently failed operating unit 10 is a first-level drill unit 10 (i.e. Figure 2 The drill unit 10-1 in the embodiment of the present invention performs the following steps 5-8.

[0205] Step 5: Based on the first starting pressure P1 of the water pump 600 corresponding to the pressure that can start the first spring 15 of the drill head unit 10 at this level, the execution module 530 controls the overflow pressure value of the overflow valve 610 to P1+1; the water pump 3 is started and mud is output to the inner cavity of the drill rod 200 until the pressure generated by the mud reaches above P1; under the action of the pressure generated by the mud, the cutting blade 12 of the drill head unit 10 that is currently in a failed state is switched from the first position to the second position to be retracted.

[0206] Step 6: The execution module 530 controls the push-pull motor 320 to move upward to pull up the drill bit assembly 100, and controls the rotary motor 310 to output at a low speed, so that the currently disabled drill bit unit 10 moves into the first working tunnel section T1.

[0207] Step 7: Acquire the position information of the push-pull motor 320 in real time based on the push-pull speed output by the push-pull motor 320 .

[0208] Step 8: When the push-pull motor 320 is detected to move to a preset position on the guide rail 710 (for example, L1=-500mm, where the difference between L1 and L0 can be set as the axial length of the drill unit 10), that is, it is confirmed that the failed drill unit 10 has completely entered the first operating channel section T1, the data analysis module 520 determines that the drill unit 10 has been replaced, and the execution module 530 stops outputting the control signal.

[0209] Step 9: If the current level of the drill unit 10 is the second level or later (ie, drill unit 10-2 or later), execute the following steps 10-11.

[0210] Step 10: Based on the second starting pressure P2 of the water pump 600 corresponding to the pressure that can start the second spring 18 of the previous-level drill unit 10, the execution module 530 controls the overflow pressure value of the overflow valve 610 to be P2+1; the water pump 3 is started and mud is output to the inner cavity of the drill rod 200 until the pressure of the mud therein reaches above P2; under the action of the pressure generated by the mud, the mud in the previous-level drill unit 10 flows into the current-level drill unit 10, so that the cutting blade 12 of the current-level drill unit 10, which is currently in an invalid state, switches from the first position to the second position, thereby realizing retraction.

[0211] Step 11: Follow steps 7 and 8 above.

[0212] Here, pressure value P1+1 refers to a pressure value slightly greater than pressure value P1, and pressure value P2+1 refers to a pressure value slightly greater than pressure value P2. These values are not limited to a specific value of 1 MPa greater. Because there is a certain distance between water pump 600 and drill head assembly 100, this slightly greater pressure value is set to overcome the pressure loss along the pipeline system between water pump 600 and drill head assembly 100 and local pressure loss.

[0213] Here, the pressure actually refers to the pressure of the fluid that can be controlled by the overflow valve (i.e., pressure), but in engineering practice it is usually called pressure. Here, the output pressure / starting pressure of the water pump 600 and the overflow pressure of the overflow valve 610 follow this term in the engineering field, which is specially explained.

[0214] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, ordinary technicians in the field should understand that without departing from the principles of the present invention, the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents. These modifications and equivalent replacements should all be included in the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A drill bit assembly (100) having a rotation axis (1a), characterized in that: It comprises at least two drill head units (10) connected in series along the direction of the rotation axis (1a), and the drill head unit (10) comprises: a base (11) connected to the base (11) of the adjacent drill unit (10); and A cutting blade (12) is connected to the outer periphery of the base (11), the cutting blade (12) having a first position opened relative to the base (11) and a second position retracted relative to the base (11), The rotary diameter of the drill unit (10) when the cutting blade (12) is in the first position is greater than the rotary diameter when the cutting blade (12) is in the second position, and when the cutting blade (12) is in the second position, the drill unit (10) is configured to be able to pass through the working channel (T) where the drill assembly (100) is located.

2. The drill bit assembly (100) according to claim 1, characterized in that The drill unit (10) comprises a plurality of cutting blades (12), and the plurality of cutting blades (12) are evenly connected to the outer periphery of the base (11).

3. The drill bit assembly (100) according to claim 1, characterized in that The drill unit (10) further comprises a driving mechanism, which is arranged between the base (11) and the cutting blade (12) to drive the cutting blade (12) to move relative to the base (11) and switch from the first position to the second position.

4. The drill bit assembly (100) according to claim 3, characterized in that A raised portion (111) is provided on the outer periphery of the base (11), the cutting blade (12) is hinged to the raised portion (111), and the hinge axis is perpendicular to the rotation axis (1a). A receiving hole (112) extending in the direction of the rotation axis (1a) is provided in the radial middle portion of the base (11), the receiving hole (112) having a first receiving hole end (M) close to the working direction of the drill bit assembly (100) and a second receiving hole end (N) away from the working direction, a first through hole (112a) is provided on the hole wall of the receiving hole (112), and in the direction of the rotation axis (1a), the first through hole (112a) is located between the protrusion (111) and the second receiving hole end (N), The driving mechanism comprises a piston (13) and a first push rod (14), The piston (13) is slidably disposed in the accommodating hole (112), and the piston (13) is provided with a first guide surface (13a). The radial distance between the first guide surface (13a) and the rotation axis (1a) changes along the direction of the rotation axis (1a). The first push rod (14) is inserted into the first through hole (112a), and one end of the first push rod (14) located radially outside the accommodating hole (112) abuts against the cutting blade (12), and the other end abuts against the first guide surface (13a). The piston (13) is configured to slide along the direction of the rotation axis (1a) to push the first push rod (14) to move along the first through hole (112a), thereby pushing the cutting blade (12) to rotate around the protrusion (111) to switch from the first position to the second position.

5. The drill bit assembly (100) according to claim 4, characterized in that The drill unit (10) further comprises a first limiting structure, which is configured to position the piston (13) axially relative to the accommodating hole (112) after the cutting blade (12) switches from the first position to the second position.

6. The drill bit assembly (100) according to claim 4, characterized in that A first guide groove (131) is provided on the outer periphery of the piston (13), the first push rod (14) abuts against the first guide groove (131), the first guide surface (13a) is formed at the bottom of the first guide groove (131), and the radial distance between the bottom of the first guide groove (131) and the rotation axis (1a) gradually decreases in a direction approaching from the first end (M) of the accommodating hole to the second end (N) of the accommodating hole.

7. The drill bit assembly (100) according to claim 6, characterized in that The first guide groove (131) has a first guide groove first end (1311) close to the second end (N) of the accommodating hole and a first guide groove second end (1312) close to the first end (M) of the accommodating hole. When the cutting knife (12) is in the first position, the first push rod (14) abuts against the first guide groove first end (1311). When the cutting knife (12) is in the second position, the first push rod (14) abuts against the first guide groove second end (1312).

8. The drill bit assembly (100) according to claim 4, characterized in that A second through hole (112b) is further provided on the hole wall of the accommodating hole (112). In the direction of the rotation axis (1a), the second through hole (112b) is located between the protruding portion (111) and the first end (M) of the accommodating hole. The driving mechanism further comprises a second push rod (16), the second push rod (16) being passed through the second through hole (112b), and one end of the second push rod (16) being located radially outside the accommodating hole (112) abuts against the cutting blade (12), and the other end abuts against the piston (13).

9. The drill bit assembly (100) according to claim 8, characterized in that The extension direction of the first through hole (112a) and / or the second through hole (112b) is perpendicular to the direction of the rotation axis (1a).

10. The drill bit assembly (100) according to claim 4, characterized in that A limiting convex portion (1121) is provided on the inner wall of the accommodating hole (112) near the second end (N) of the accommodating hole. The driving mechanism further comprises a first spring (15), which is arranged between the piston (13) and the limiting convex portion (1121).

11. The drill bit assembly (100) according to claim 10, characterized in that The accommodating hole (112) is continuous along the direction of the rotation axis (1a). The piston (13) is sealed with the wall of the accommodating hole (112) in the circumferential direction and is provided with a flow channel running through it, the flow channel comprising a flow channel inlet (m) close to the first end (M) of the accommodating hole and in fluid communication therewith, and a flow channel outlet (n) close to the second end (N) of the accommodating hole and in fluid communication therewith, The drill unit (10) further comprises a pressure relief component, which is arranged in the flow channel and has a closed state and an open state, and the pressure relief component is configured as follows: When the fluid pressure at the flow channel inlet (m) is less than or equal to a preset pressure, the device is in the closed state to block the flow channel, thereby cutting off the fluid communication between the first end (M) of the receiving hole and the second end (N) of the receiving hole; as well as When the fluid pressure at the flow channel inlet (m) is greater than the preset pressure, it switches to the open state to release the blockage of the flow channel, thereby allowing the first end (M) of the accommodating hole and the second end (N) of the accommodating hole to be fluidically connected.

12. The drill bit assembly (100) according to claim 11, characterized in that The flow channel comprises a first flow channel section (1301) and a second flow channel section (1302) which are connected to each other, wherein the first flow channel section (1301) extends along the direction of the rotation axis (1a) and is connected to the flow channel inlet (m), and the second flow channel section (1302) is perpendicular to the first flow channel section (1301) and is connected to the flow channel outlet (n). The pressure relief assembly comprises a valve core (17) and a second spring (18) arranged in the first flow channel section (1301), wherein the second spring (18) is arranged between the valve core (17) and an axial end portion of the first flow channel section (1301) close to the second end (N) of the accommodating hole, and the valve core (17) is configured as follows: In the closed state of the pressure relief assembly, the connection between the first flow channel section (1301) and the second flow channel section (1302) is blocked; and When the pressure of the fluid in the first flow channel section (1301) is greater than the preset pressure, the second spring (18) is squeezed under the push of the fluid and moves toward the axial end of the first flow channel section (1301) to release the blockage of the connection point.

13. The drill bit assembly (100) according to claim 12, characterized in that A fitting portion (13011) is provided at the connection point between the first flow channel section (1301) and the second flow channel section (1302). In the closed state of the pressure relief assembly, the fitting portion (13011) abuts against and is in close contact with the end of the valve core (17) away from the second spring (18).

14. The drill head assembly (100) according to claim 12, characterized in that When the cutting blade (12) is in the first position, the first spring (15) is compressed and has a first preload force, and the second spring (18) is compressed and has a second preload force, wherein: In the same drill head unit (10), the first preload force of the first spring (15) is smaller than the second preload force of the second spring (18); and Along the direction of the rotation axis (1a), the second preload force of the second spring (18) of the drill head unit (10) close to the working direction of the drill head assembly (100) is smaller than the second preload force of the second spring (18) of the drill head unit (10) away from the working direction of the drill head assembly (100).

15. The drill bit assembly (100) according to claim 1, characterized in that The cutting blade (12) is provided with a first cutting surface (12a) and a second cutting surface (12b) connected to the first cutting surface (12a) at one end thereof close to the working direction of the drill bit assembly (100); when the cutting blade (12) is in the first position, the first cutting surface (12a) is perpendicular to the rotation axis (1a), and the second cutting surface (12b) is parallel to the rotation axis (1a).

16. The drill head assembly (100) according to claim 1, characterized in that The cutting blade (12) is provided with a third cutting surface, the third cutting surface (12c) being located on a side of the cutting blade (12) facing away from the base (11), and when the cutting blade (12) is in the second position, the third cutting surface (12c) is parallel to the rotation axis (1a).

17. The drill bit assembly (100) according to claim 1, characterized in that A chip removal groove (121) is provided on a side of the cutting blade (12) close to the base (11).

18. The drill head assembly (100) according to claim 17, characterized in that The chip removal groove (121) is a sawtooth groove.

19. The drill head assembly (100) according to claim 1, characterized in that The bases (11) of two adjacent drill head units (10) are detachably connected.

20. A hole enlarging device, characterized in that: include: The drill bit assembly (100) according to any one of claims 1 to 19; A drill rod (200) connected to the drill bit assembly (100); a drilling rig (300) connected to an end of the drill rod (200) away from the drill bit assembly (100), the drilling rig (300) being configured to drive the drill rod (200) to move along an operating direction, thereby driving the drill bit assembly (100) to move along the operating direction to expand the operating tunnel (T); A detection device (400) configured to detect an operating state of at least the drill unit (10) of the drill assembly (100) that is in a working position; and The controller (500) is configured to: receiving a signal from the detection device (400); In response to a signal detected by the detection device (400) indicating that the drill unit (10) in the working position is in a failed state, the cutting blade (12) of the drill unit (10) in the failed state is controlled to switch to the second position; and The drilling rig (300) is controlled to drive the drill rod (200) to move along the working direction, so as to pull the drill head unit (10) in the failed state to move into the working tunnel (T), and to move the next drill head unit (10) in series on the side of the drill head unit (10) in the failed state away from the drilling rig (300) to the working position.

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