Directional geotechnical investigation coring device based on cylindrical magnetic suspension

Abstract

The present application relates to the field of geotechnical investigation coring, and discloses a directional geotechnical investigation coring device based on a cylindrical magnetic suspension, which comprises a directional outer pipe assembly, a magnetic suspension inner pipe assembly and a directional control system; the directional outer pipe assembly comprises a drill bit, an outer pipe body, an annular radial suspension stator, a long stator linear motor winding and a snap fastener; the outer pipe body is threadedly connected with the drill bit, the annular radial suspension stator is arranged in a circumferential annular manner along the inner wall of the outer pipe body, and the long stator linear motor winding is embedded in an axial groove in the inner wall of the outer pipe body. The present application has the following advantages and effects: the coring device based on the principle of cylindrical magnetic suspension realizes contactless suspension and directional accurate driving, is suitable for directional drilling operations of different inclination angles, can flexibly match the directional drilling track, realizes accurate running-in of the coring pipe along the directional track, sampling and lifting, and guarantees the integrity of the rock core throughout the whole process.

Description

Technical Field

[0001] This invention relates to the field of geotechnical exploration and coring technology, and in particular to a directional geotechnical exploration and coring device based on cylindrical magnetic levitation. Background Technology

[0002] Geotechnical engineering investigation is a fundamental preliminary work for underground engineering construction, geological disaster management, and mineral resource exploration. Directional core drilling technology can complete deep strata sampling along unconventional trajectories such as dips and curves, accurately obtaining undisturbed soil and rock samples at different locations and depths under complex working conditions. It has now become a core technology for deep geological exploration and underground space development. Currently, most mainstream directional core drilling devices on the market adopt traditional rigid mechanical joint structures, relying on the mechanical cooperation of drill rods and inner tube assemblies to achieve lowering and retrieval of core samples. However, the following problems still exist in the actual directional drilling construction process:

[0003] (1) Directional drilling is mostly inclined or curved. The core tube of the traditional device has a large contact area with the borehole wall, resulting in large mechanical friction. The frictional resistance combined with the directional gravity offset can easily lead to the core tube offset and twisting, resulting in low retrieval efficiency. It may also cause the core tube to get stuck or damaged, which cannot meet the needs of high-precision directional exploration.

[0004] (2) Under the directional inclined trajectory, the mechanical friction between the core tube and the borehole wall is intensified, which can easily cause the core tube to vibrate and deviate, resulting in the core breaking and falling off, making it difficult to obtain the original core sample;

[0005] (3) Existing wireline coring mainly relies on the self-weight of the retrieval mechanism or hydraulic drive to reach the inner tube position to realize the deployment and retrieval of the inner tube assembly. For drilling operations with small inclination angles or negative angles, it is difficult for the retrieval device to reach the inner tube position.

[0006] (4) Mechanical transmission components are susceptible to erosion by mud and rock cuttings, resulting in severe wear and frequent maintenance, which reduces work efficiency and increases construction costs;

[0007] (5) The existing inner tube is a long cylindrical structure. When the rock core is a soil sample, the rock core should not be taken out from the inner tube due to the poor structure of the soil and the looseness of the soil.

[0008] Therefore, it is necessary to design a directional rock and soil exploration core sampling device based on cylindrical magnetic levitation to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide a directional rock and soil exploration core sampling device based on cylindrical magnetic levitation to solve the above-mentioned problems.

[0010] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a directional rock and soil exploration core sampling device based on cylindrical magnetic levitation, comprising:

[0011] Orientation outer tube assembly, magnetic levitation inner tube assembly, and orientation control system;

[0012] The directional outer tube assembly includes a drill bit, an outer tube body, an annular radial suspension stator, a long stator linear motor winding, and a spring clip retainer.

[0013] The outer tube body is threadedly connected to the drill bit, the annular radial suspension stator is arranged circumferentially along the inner wall of the outer tube body, the long stator linear motor winding is embedded in the axial groove of the inner wall of the outer tube body, and the spring clip retainer is located at the rear of the outer tube body and threadedly connected to the outer tube body.

[0014] The magnetic levitation inner tube assembly includes a core-taking one-way valve, a split-mold core-taking tube, a straightening ring, a magnetic levitation actuator assembly, and a spring clip.

[0015] The split mold core-taking tube is threadedly connected to the core-taking one-way valve, the straightening ring is fixedly installed inside the front end of the outer tube body, the magnetic levitation actuator is located on the outer wall of the split mold core-taking tube, and the spring clip is threadedly connected to the split mold core-taking tube.

[0016] A further embodiment of the present invention is that the orientation control system includes a ground control host, a driver, and an orientation adjuster.

[0017] A further feature of the present invention is that the drill bit is a hollow cylindrical tube, and the end of the drill bit is serrated.

[0018] A further feature of the present invention is that the outer tube body is composed of multiple hollow cylinders, and the annular radially suspended stator is a superconducting coil.

[0019] A further feature of the present invention is that the core-taking one-way valve is located at the front end of the magnetic levitation inner tube assembly, the core-taking one-way valve is composed of multiple inwardly bent baffles, and the core-taking tube is a hollow cylinder.

[0020] A further configuration of the present invention is that the magnetic levitation mover assembly includes a radially levitated mover and an axially driven mover, wherein the radially levitated mover is a ring-shaped permanent magnet array and the axially driven mover is a permanent magnet array.

[0021] A further feature of the present invention is that the spring clip is located at the rear end of the split mold core tube.

[0022] A further provision of the present invention is that the driver is electrically connected to the ground control host.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention adopts the principle of cylindrical magnetic levitation to achieve non-contact levitation of the core sampling tube and the outer tube body, eliminating the mechanical friction interference between the core sampling tube and the borehole wall during directional drilling, avoiding friction and vibration between the core sampling tube and the borehole wall, making the core sampling process stable. With the core sampling one-way valve, it can effectively prevent the rock core from breaking and falling off. The obtained rock core sample retains its original structure and can truly reflect the rock and soil characteristics of different strata on the directional trajectory, providing accurate data support for stratigraphic analysis.

[0025] 2. This invention uses magnetic levitation to drive the split-mold coring tube to achieve uniform lowering and lifting along a directional trajectory, eliminating the need to raise or lower the drill rod and improving coring efficiency. The absence of mechanical contact friction reduces drive energy consumption, maintenance costs, and service life. The magnetic levitation principle enhances the device's adaptability to directional drilling at different inclination angles. The magnetic levitation system provides propulsion to the split-mold coring tube, enabling it to reach positions inaccessible by gravity or hydraulic drive alone. The split-mold design of the coring tube avoids the problem of difficult core extraction. Attached Figure Description

[0026] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary. The structures, proportions, sizes, etc., drawn in this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance, and any modification of the structure, change of the proportional relationship, or adjustment of the size is not permitted.

[0027] Figure 1 This is a schematic diagram of the structure of a directional rock and soil exploration core sampling device based on cylindrical magnetic levitation proposed in this invention.

[0028] Figure 2 This is a structural schematic diagram of the directional outer tube assembly.

[0029] Figure 3 This is a schematic diagram of the magnetic levitation inner tube assembly.

[0030] In the diagram, 1. Drill bit; 2. Outer tube body; 3. Annular radial suspension stator; 4. Long stator linear motor winding; 5. Spring clip holder; 6. Core sampling check valve; 7. Split mold core sampling tube; 8. Centralizing ring; 9. Magnetic levitation mover assembly; 10. Spring clip holder; 11. Ground control host; 12. Driver; 13. Orientation adjuster. Detailed Implementation

[0031] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "circumferential," and "radial," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more unless otherwise explicitly specified.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] See Figure 1 , Figure 2 and Figure 3 This invention provides a directional rock and soil exploration core sampling device based on cylindrical magnetic levitation, comprising:

[0037] Orientation outer tube assembly, magnetic levitation inner tube assembly, and orientation control system;

[0038] The directional outer tube assembly includes a drill bit 1, an outer tube body 2, an annular radial suspension stator 3, a long stator linear motor winding 4, and a spring clip retainer 5;

[0039] The outer tube body 2 is threadedly connected to the drill bit 1. The annular radial suspension stator 3 is arranged circumferentially along the inner wall of the outer tube body 2. The long stator linear motor winding 4 is embedded in the axial groove of the inner wall of the outer tube body 2. The spring clip retainer 5 is located at the rear of the outer tube body 2 and is threadedly connected to the outer tube body 2.

[0040] The magnetic levitation inner tube assembly includes a core-taking one-way valve 6, a split mold core-taking tube 7, a straightening ring 8, a magnetic levitation actuator assembly 9, and a card ejector 10;

[0041] The split mold core extraction tube 7 is threadedly connected to the core extraction one-way valve 6, the straightening ring 8 is fixedly installed inside the front end of the outer tube body 2, the magnetic levitation actuator assembly 9 is located on the outer wall of the split mold core extraction tube 7, and the spring clip 10 is threadedly connected to the split mold core extraction tube 7.

[0042] Specifically, the orientation control system includes a ground control host 11, a drive 12, and an orientation adjuster 13.

[0043] Through the above structure, the ground control host 11 is equipped with dedicated directional control software, which displays the directional drilling trajectory, core tube inclination angle, displacement data, and core depth. It supports parameter settings and adjusts the core tube drive parameters and core position according to the directional trajectory requirements to achieve synchronous coordination between the directional trajectory and the core operation. The driver 12 adjusts the magnetic field strength of the annular radial suspension stator 3 according to the instructions of the ground control host 11 to counteract the gravitational offset of the open-form core tube 7 and achieve stable control of the suspension gap of the open-form core tube 7; it also adjusts the winding 4 of the long stator linear motor to drive the open-form core tube 7 to descend and lift at a uniform speed along the directional trajectory. The base of the directional adjuster 13 adopts a weighted adjustable structure with an anti-slip fixing device at the bottom, which can be fixed to the ground or drilling platform by expansion bolts. The upper part is an adjustable support plate to ensure the overall stability of the device during directional drilling. The inclination angle of directional drilling can be set by adjusting the support plate. The outer tube body 2 is supported by the support plate before entering the soil and enters the soil along the inclination angle set by the support plate.

[0044] Specifically, drill bit 1 is a hollow cylindrical tube, and the end of drill bit 1 is serrated.

[0045] With the above structure, drill bit 1 is located at the front end of the directional outer tube assembly. It is a hollow cylindrical tube made of high-strength wear-resistant material and is serrated, which can cut soil samples during drilling.

[0046] Specifically, the outer tube body 2 is composed of multiple hollow cylinders, and the annular radial suspension stator 3 is a superconducting coil.

[0047] Through the above structure, the outer tube body 2 is made of high-strength wear-resistant material. The outermost section of the outer tube body 2 has a thickened wall, so that the outer diameter remains unchanged while the inner diameter decreases. As drilling progresses, the number of sections of the outer tube body is continuously increased according to the drilling depth, so that the length of the outer tube body 2 is basically consistent with the drilling depth. The annular radial suspension stator 3 is a uniformly distributed superconducting coil, arranged circumferentially along the inner wall of the outer tube body 2, used to generate a radially uniform magnetic field to achieve radial centering and suspension of the core tube, counteracting the gravitational offset of the core tube under directional tilt, and ensuring that the core tube always runs along the axis of the outer tube body 2. The long stator linear motor winding 4 cooperates with the magnetic levitation mover assembly on the core tube to generate axial driving force along the axis of the outer tube body 2, completing the lowering and lifting operation of the core tube and ensuring stable operation. The spring clip retainer 5 is located at the rear of the outermost section of the outer tube body 2 and is used to fix the spring clip.

[0048] Specifically, the core-taking one-way valve 6 is located at the front end of the magnetic levitation inner tube assembly. The core-taking one-way valve 6 is composed of multiple inwardly bent baffles, and the core-taking tube 7 is a hollow cylinder.

[0049] With the above structure, the one-way valve 6 for core sampling consists of multiple inwardly bent baffles. When the core enters the split-mold core sampling tube, the baffles open under external pressure; when the core enters the split-mold core sampling tube, the baffles close under internal pressure to prevent the core from falling out. The split-mold core sampling tube 7 is divided into two along the axial direction, with several interlocking surfaces on the separation surface.

[0050] The straightening ring 8 is fitted at the front end of the split mold core tube 7 and is made of elastic material. When the split mold core tube 7 enters the outer tube body 2, the inner diameter becomes smaller due to the thickening of the tube wall at the front end of the outer tube body 2. The straightening ring 8 fixes the split mold core tube 7 inside the outer tube body 2.

[0051] Specifically, the magnetic levitation mover assembly 9 includes a radially levitated mover and an axially driven mover. The radially levitated mover is a ring-shaped permanent magnet array, and the axially driven mover is a permanent magnet array.

[0052] Through the above structure, the radial suspension mover is a ring-shaped permanent magnet array, which is like-paired and repulsive with the ring-shaped radial suspension stator 3 on the inner wall of the outer tube body 2. This enables the core tube 7 to be automatically centered and suspended radially in the outer tube body 2. It can automatically counteract the gravitational offset of the core tube 7 under directional tilt, ensuring suspension stability and avoiding friction caused by contact between the core tube 7 and the outer tube body 2. The axial drive mover is a permanent magnet array, which cooperates with the long stator linear motor winding 4 on the inner wall of the outer tube body 2 to receive axial driving force and drive the core tube 7 to be lowered and lifted at a uniform speed along the directional trajectory. The operation is smooth and vibration-free, avoiding core breakage.

[0053] Specifically, the ejector 10 is located at the rear end of the split mold core tube 7.

[0054] With the above structure, when the core-taking tube 7 of the mold-opening device enters the outer tube body 2, the spring clip 10 opens and engages with the spring clip retainer 5 to fix the magnetic levitation inner tube assembly inside the directional outer tube assembly.

[0055] Specifically, the driver 12 is electrically connected to the ground control host 11.

[0056] Working principle:

[0057] During directional drilling, the directional adjuster 13 is fixed to the ground or drilling platform. The angle of the support plate is adjusted and fixed according to the required inclination angle of directional drilling. The magnetic levitation inner tube assembly is placed into the directional outer tube assembly. At this time, due to the thickening of the front wall of the outer tube body 2, the inner diameter becomes smaller. At the same time, the spring clip 10 is opened and engaged with the spring clip fixing device 5, so that the split mold core tube 7 is fixed inside the outer tube body 2.

[0058] The directional outer tube assembly, together with the magnetic levitation inner tube assembly, is placed into the support plate of the directional adjuster 13. The drilling rig is started, causing the outer tube assembly and the magnetic levitation inner tube assembly to rotate, so that the drill bit 1 begins to cut the soil. At this time, the baffle of the core sampling one-way valve 6 is opened by external pressure, and the rock core enters the split mold core tube 7. When the split mold core tube 7 is full of rock core, the baffle of the core sampling one-way valve 6 is closed by internal pressure to prevent the rock core from falling. At the same time, the ground control host 11 issues a lifting command, and the driver 12 adjusts the magnetic field strength of the annular radial suspension stator 3, which interacts with the magnetic levitation mover assembly 9 to counteract the gravity offset of the split mold core tube 7 and achieve stable control of the suspension gap of the split mold core tube 7. The long stator linear motor winding 4 is adjusted to interact with the magnetic levitation mover assembly 9, driving the split mold core tube 7 to be lifted at a constant speed along the directional trajectory.

[0059] When the split-mold core tube 7 begins to be lifted, the spring clip 10 and the spring clip retainer 5 begin to separate under the lifting force, and the split-mold core tube 7 reaches the ground along the outer tube body 2; the split-mold core tube 7 is opened and the rock core is taken out; the split-mold core tube 7 is reinstalled, and the lifting command is issued through the ground control host 11. The driver 12 adjusts the magnetic field strength of the annular radial suspension stator 3, which interacts with the magnetic levitation mover assembly 9 to counteract the gravity offset of the split-mold core tube 7 and achieve stable control of the suspension gap of the split-mold core tube 7; the long stator linear motor winding 4 is adjusted to interact with the magnetic levitation mover assembly 9, driving the split-mold core tube 7 to descend into the outer tube body 2 at a uniform speed along the directional trajectory.

[0060] When the split-mold core sampling tube 7 reaches the foremost section of the outer tube body 2, the inner diameter decreases due to the thickened front wall of the outer tube body 2. The centering ring 8 can then be secured within the front wall of the outer tube body 2. Simultaneously, the spring clip 10 opens and engages with the spring clip retainer 5, fixing the split-mold core sampling tube 7 within the outer tube body 2. The drilling rig is then restarted, causing the outer tube assembly and the magnetically levitated inner tube assembly to rotate, allowing the drill bit 1 to begin cutting the soil. This sampling process is repeated. As the drilling distance increases, the number of sections in the outer tube body 2 needs to be continuously increased.

[0061] The foregoing has provided a detailed description of a directional rock and soil exploration core sampling device based on cylindrical magnetic levitation provided by the present invention. Specific embodiments have been used to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A directional rock and soil exploration core sampling device based on cylindrical magnetic levitation, characterized in that, include: Orientation outer tube assembly, magnetic levitation inner tube assembly, and orientation control system; The directional outer tube assembly includes a drill bit (1), an outer tube body (2), an annular radial suspension stator (3), a long stator linear motor winding (4), and a spring clip retainer (5). The outer tube body (2) is threadedly connected to the drill bit (1), the annular radial suspension stator (3) is arranged circumferentially along the inner wall of the outer tube body (2), the long stator linear motor winding (4) is embedded in the axial groove of the inner wall of the outer tube body (2), and the spring clip retainer (5) is located at the rear of the outer tube body (2) and threadedly connected to the outer tube body (2). The magnetic levitation inner tube assembly includes a core-taking one-way valve (6), a split-mold core-taking tube (7), a straightening ring (8), a magnetic levitation actuator assembly (9), and a card ejector (10). The split mold core-taking tube (7) is threadedly connected to the core-taking one-way valve (6), the straightening ring (8) is fixedly installed inside the front end of the outer tube body (2), the magnetic levitation actuator assembly (9) is located on the outer wall of the split mold core-taking tube (7), and the spring clip (10) is threadedly connected to the split mold core-taking tube (7).

2. The directional rock and soil exploration core sampling device based on cylindrical magnetic levitation according to claim 1, characterized in that, The orientation control system includes a ground control host (11), a driver (12), and an orientation adjuster (13).

3. The directional rock and soil exploration core sampling device based on cylindrical magnetic levitation according to claim 1, characterized in that, The drill bit (1) is a hollow cylindrical tube, and the end of the drill bit (1) is serrated.

4. The directional rock and soil exploration core sampling device based on cylindrical magnetic levitation according to claim 1, characterized in that, The outer tube body (2) is composed of multiple hollow cylinders, and the annular radial suspension stator (3) is a superconducting coil.

5. A directional rock and soil exploration core sampling device based on cylindrical magnetic levitation according to claim 1, characterized in that, The core-taking one-way valve (6) is located at the front end of the magnetic levitation inner tube assembly. The core-taking one-way valve (6) is composed of multiple inwardly bent baffles, and the core-taking tube (7) is a hollow cylinder.

6. The directional rock and soil exploration core sampling device based on cylindrical magnetic levitation according to claim 1, characterized in that, The magnetic levitation mover assembly (9) includes a radially levitated mover and an axially driven mover. The radially levitated mover is a ring-shaped permanent magnet array, and the axially driven mover is a permanent magnet array.

7. A directional rock and soil exploration core sampling device based on cylindrical magnetic levitation according to claim 1, characterized in that, The ejector (10) is located at the rear end of the split mold core tube (7).

8. A directional rock and soil exploration core sampling device based on cylindrical magnetic levitation according to claim 2, characterized in that, The driver (12) is electrically connected to the ground control host (11).

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