Trigger type reducing rock coring device and coring method

Abstract

The invention belongs to the field of drilling sampling, and discloses a trigger type variable-diameter rock coring device and coring method.The trigger type variable-diameter rock coring device comprises a coring barrel, a cutting assembly and a sealing assembly; a sealing assembly is fixed to the bottom of the flexible cylinder. A supporting rod is arranged on the inner side of the supporting frame in a sliding mode, the bottom of the supporting rod is rotationally connected with a cutting assembly through a rotating shaft, and the working face of the cutting assembly and the sealing end face of the sealing assembly are parallel and axially aligned. The axis direction of the rotating shaft is perpendicular to the axis of the coring barrel, a linkage plate is arranged between the cutting assembly and the sealing assembly, when the cutting assembly is subjected to radial acting force pointing to the axis of the coring barrel, the sealing assembly is driven by the linkage plate to execute synchronous centripetal deflection, and the cutting assembly and the sealing assembly achieve synchronous centripetal deflection through the linkage plate. When the cutting assembly encounters a hard rock stratum or an uneven surface, the action that the cutting assembly is driven by radial acting force to gather inwards can actively avoid a non-uniform stress area of an uneven hard block at the upper end.

Description

Technical Field

[0001] This disclosure pertains to the field of drilling and sampling, specifically relating to a trigger-type variable diameter rock coring device and coring method. Background Technology

[0002] In geological exploration, mineral resource assessment, civil engineering surveys, and scientific research, it is necessary to obtain undisturbed rock core samples from underground through drilling. These samples provide crucial first-hand information on stratigraphic structure, lithology, mineral composition, mechanical properties, and paleoenvironment, serving as the direct basis for geological analysis, resource reserve calculations, and engineering design decisions.

[0003] Core sampling is widely applicable to various geological environments, including but not limited to: mineral resource exploration (such as metal mines and coal), hydrogeological surveys, foundation investigation for civil engineering projects (such as dams, bridges, and high-rise buildings), scientific drilling (such as deep crustal exploration), and geological disaster prevention and control surveys. However, geological conditions are complex and varied. In actual drilling, the drill bit often traverses strata with weak mechanical support, consisting of loose sand, gravel, and quicksand. For such geological conditions, the drilling speed of the drill bit is 0.5-1.5 m / s, and the feed pressure is 50-1000 N. The lower rotation speed and lower feed pressure can ensure that the disturbance to the sand and gravel is reduced during drilling, and the original state of the sample is preserved to the greatest extent.

[0004] For example, the core cutting and sealing device and sampling device disclosed in CN114112491B can automatically switch between "open state" (allowing material to enter the core tube) and "sealed state" (cutting off and sealing the material) by setting a sealing structure (such as multiple ring-shaped sealing elements). It integrates core cutting, cutting off and sealing functions into the same device. The sealing is triggered by the movement of the material itself, without the need for an additional power source, reducing equipment complexity and energy consumption.

[0005] However, the existing cutting and support components are rigidly connected, which means that when the drill bit cuts hard rock, the shelter applies a deflection force to the drill bit. When drilling continues downward, the stress concentrates at the connection between the support and cutting components, which can easily cause the drill bit to get stuck. Furthermore, due to the low overall strength of the sand and gravel, the drill bit can deflect without restraint, which can easily cause the sand and gravel structure to collapse and damage the outer wall of the sample. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this disclosure is to provide a trigger-type variable diameter rock coring device and coring method, which solves the risk of drill bit jamming caused by the rigid connection between the cutting component and the support component, and the uneven force on the cutting component when encountering uneven hard blocks at the upper end during the cutting process.

[0007] The objective of this disclosure can be achieved through the following technical solutions:

[0008] A trigger-type variable diameter rock coring device includes: a coring cylinder, a cutting assembly, and a sealing assembly;

[0009] The outer wall of the core sampling tube is provided with a support frame, the bottom of the core sampling tube is slidably connected to a flexible tube, and the bottom of the flexible tube is fixed with a sealing component.

[0010] A support rod is slidably provided on the inner side of the support frame, and a cutting component is rotatably connected to the bottom of the support rod via a rotating shaft. The working surface of the cutting component is parallel to and axially aligned with the sealing end face of the sealing component.

[0011] The axis of the rotating shaft is perpendicular to the axis of the core cylinder. A linkage plate is provided between the cutting assembly and the sealing assembly. When the cutting assembly encounters hard rock or an uneven surface, the cutting assembly is subjected to a radial force pointing towards the axis of the core cylinder. The linkage plate drives the sealing assembly to perform synchronous centripetal deflection. The radial force drives the cutting assembly to move inward and actively avoid the non-uniform force area of ​​the uneven hard block at the top.

[0012] In some disclosures, the sealing assembly includes a flexible cylinder, triangular plates, a groove, and a magnet. The bottom of the core-taking cylinder is slidably provided with a flexible cylinder, and the bottom outer wall of the flexible cylinder is fixed with a groove. Multiple triangular plates are evenly distributed around the bottom end of the flexible cylinder, and magnets are fixed to the inner walls of the multiple triangular plates. The triangular plates are sewn to the flexible cylinder through a flexible connecting layer, and the upper edge of the triangular plates is tangent to the inner wall of the flexible cylinder.

[0013] In some disclosures, the flexible cylinder includes a braided layer and a covering layer. The braided layer is formed by weaving multiple stainless steel wires in a grid arrangement to create an axially reinforced structure. The covering layer covers the outer surface of the braided layer, and its outer edge is welded and fixed to the groove.

[0014] In some disclosures, the cutting assembly includes a rotating base, a micro motor, and a drill bit. The rotating base is rotatably connected to the inner side of the rotating shaft, and the micro motor is fixed to the lower end of the rotating base. The output end of the micro motor is connected to the drill bit.

[0015] In some disclosures, the upper end face of the rotating seat is provided with two rotating parts, and the central axes of the two rotating parts are arranged in parallel. The height of the end of the drill bit is lower than the height of the lower end of the triangular plate, so that the drill bit contacts the rock mass first. The end of the drill bit is fixedly provided with a sharp part. When the sharp part moves around the core tube to make a cutting motion, the inner diameter of the cutting trajectory of the sharp part is smaller than the inner diameter of the core tube.

[0016] During the cutting operation, the drill bit revolves around the axis of the core cylinder, while the pointed part rotates around its own axis to cut the sample at its bottom. The pointed part has a conical structure design.

[0017] In some disclosures, a servo motor is fixed to the top of the core sampling cylinder, and a connecting rod is fixed to the output end of the servo motor. The end of the connecting rod away from the servo motor is fixedly connected to the upper end of the support rod. A guide groove is fixed to the outside of the core sampling cylinder, and the guide groove is spiral in shape. A sleeve is slidably provided on the outside of the support rod, and a guide block is fixed to the outside of the sleeve. The shape of the guide block matches the groove opening in the guide groove, and the movement path of the guide block is the same as the path of the guide groove.

[0018] In some disclosures, the linkage plate includes a protective plate and a guide rod. The protective plate is fixed between the micro motor and the core-taking cylinder. The protective plate is arc-shaped, and the middle part of the protective plate protrudes towards the side close to the flexible cylinder, so that the protrusion contacts the outer wall of the triangular plate. The guide rod is fixed to the outer wall of the protective plate.

[0019] In some disclosures, a spherical plug is fixed to the end of the guide rod, the volume of which is adapted to the groove, and the linkage plate is fixed to the outer wall of the micro motor.

[0020] In some disclosures, a piston rod is rotatably connected to the upper end of another rotating part on the rotating seat, and a hollow rod is slidably provided on the outer side of the piston rod. An electric telescopic rod is fixed to the upper end of the hollow rod, and damping fluid is filled between the output end of the electric telescopic rod and the piston rod. The two ends of the return spring are fixedly connected to the lower end face of the piston rod and the bottom wall of the hollow rod cavity, respectively.

[0021] A method for core sampling of rocks includes the following steps:

[0022] S1. When in use, after transporting the core tube to the sampling position, start the servo motor. The servo motor drives the support rod to rotate in a circle along the support frame, which will clear away the loose sand on the surface of the sand and gravel around the core tube, making it easier for the core tube to be inserted into the sand until the lower end of the core tube reaches the upper end of the hard rock mass.

[0023] S2. Simultaneously, when the guide block on the sleeve slides along the guide groove, it drives the sleeve, cutting component and flexible cylinder to move downward synchronously. When the sand and soil outside the gravel are thick, it can increase the internal space of the core tube to accommodate more samples.

[0024] S3. When hard rocks are encountered around the core barrel, the rocks exert a radial force on the drill bit pointing towards the axis of the core barrel, thereby causing the drill bit and cutting assembly to deflect away from the rocks around the axis of rotation.

[0025] S4. Simultaneously, when the cutting component deflects, it drives the linkage plate to rotate synchronously. When the linkage plate rotates, it drives the guide rod to rotate along the spherical plug. The edge of the triangular plate gradually cuts into the center of the arc surface along the edge of the arc surface. The protective plate pushes the triangular plate in contact with the protective plate to rotate inward, and performs the inward convergence action synchronously with the cutting component, so that the diameter of the rock mass inside the core tube changes.

[0026] S5. After sampling is completed, the electric telescopic rod is extended downwards by remote control, which drives the piston rod inside the hollow rod to move downwards and presses the rotating seat to rotate around the axis, thereby actively cutting the sample at the bottom of the core tube. At this time, the movement path of the cutting component is still circular, so that the connection shape between the bottom of the sample and the rock mass after cutting is a cylindrical tube. As the inclination angle of the cutting component increases, the diameter of the cylindrical tube connecting the bottom of the sample and the rock mass decreases, and the connection strength between the sample and the bottom rock mass decreases.

[0027] S6. When the tilt angle of the cutting component increases, the distance between the magnets on the multiple triangular plates decreases. When the magnetic force of the magnets is greater than the connection strength between the sample and the rock mass, the multiple magnets attract each other and cut the sample and the rock mass. After the magnets are attached to each other, the bottom of the core tube forms a relatively sealed and closed state, thereby completing the core extraction.

[0028] The explanations of the nouns, conjunctions, or adjectives used in the above technical solutions are as follows:

[0029] A fixed connection refers to a connection in which parts or components are fixed in place and there is no relative movement between them;

[0030] A rotating connection is a connection between parts that allows the parts to rotate relative to each other.

[0031] Threaded connections are a type of detachable fixed connection with advantages such as simple structure, reliable connection, and convenient assembly and disassembly. They are widely used in mechanical engineering and connection structure fields.

[0032] A sliding connection is a connection between parts that allows the parts to slide against each other.

[0033] The beneficial effects of this disclosure are:

[0034] 1. The cutting component and the sealing component achieve synchronous centripetal deflection through the linkage plate. When the cutting component encounters hard rock layers or uneven surfaces, the radial force drives the cutting component to converge inward, which can actively avoid the non-uniform force area of ​​the uneven hard block at the top.

[0035] 2. The triangular plate of the sealing component is sewn to the flexible cylinder through a flexible connecting layer. When subjected to radial force, it can deflect centripetally to dynamically adjust the contact pressure with sand and gravel. Its coordinated deformation capability with the cutting component ensures stable sampling in complex sand and gravel environments.

[0036] 3. When the sample itself has low gravity and loose structure, the connection strength between the bottom of the sample and the rock mass is reduced by cutting components. Then, the bottom of the sample is cut by a triangular plate. When the sample has a weak reaction force, the magnet is attracted and closed to form a bottom seal, reducing the energy waste of driving the additional seal and adapting to the energy-limited conditions of the detector. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this disclosure;

[0039] Figure 2 This is a schematic diagram of the connection structure between the servo motor and the connecting rod according to an embodiment of the present disclosure;

[0040] Figure 3 This is a schematic diagram of the connection structure between the flexible cylinder and the sealing assembly according to an embodiment of this disclosure;

[0041] Figure 4 This is a schematic diagram of the overall structure of the cutting component according to an embodiment of the present disclosure;

[0042] Figure 5 This is a schematic diagram of the internal structure of the hollow rod according to an embodiment of the present disclosure;

[0043] Figure 6 This is a schematic diagram of the connection structure between the flexible cylinder and the sealing assembly according to an embodiment of this disclosure;

[0044] Figure 7 This is a schematic diagram of the cross-sectional structure of a single triangular plate according to an embodiment of this disclosure;

[0045] Figure 8 This is a schematic diagram of the internal cross-sectional structure of the flexible cylinder according to an embodiment of the present disclosure;

[0046] Figure 9 This is a schematic diagram of the borehole cross-section when the sealing assembly of this embodiment is closed.

[0047] In the diagram: 1. Core tube; 2. Support frame; 3. Flexible tube; 31. Braided layer; 32. Covering layer; 4. Cutting assembly; 41. Rotating seat; 42. Micro motor; 43. Drill bit; 411. Rotating part; 431. Sharp part; 5. Sealing assembly; 51. Triangular plate; 52. Slide groove; 53. Magnet; 511. Flexible connecting layer; 6. Support rod; 7. Rotating shaft; 8. Linkage plate; 81. Protective plate; 82. Guide rod; 821. Spherical plug; 9. Servo motor; 10. Connecting rod; 11. Guide groove; 12. Sleeve; 13. Guide block; 14. Piston rod; 15. Hollow rod; 16. Electric telescopic rod; 17. Return spring. Detailed Implementation

[0048] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0049] Please refer to Figures 1 to 9 A trigger-type variable diameter rock coring device includes: a coring cylinder 1, a cutting assembly 4, and a sealing assembly 5;

[0050] The outer wall of the core sampling cylinder 1 is provided with a support frame 2, and the bottom of the core sampling cylinder 1 is slidably connected to a flexible cylinder 3, and the bottom of the flexible cylinder 3 is fixed with a sealing component 5.

[0051] A support rod 6 is slidably provided on the inner side of the support frame 2. The bottom of the support rod 6 is rotatably connected to the cutting component 4 through the rotating shaft 7. The working surface of the cutting component 4 is parallel to and axially aligned with the sealing end face of the sealing component 5.

[0052] The axis of the rotating shaft 7 is perpendicular to the axis of the core-taking cylinder 1, and a linkage plate 8 is provided between the cutting assembly 4 and the sealing assembly 5;

[0053] When the cutting component 4 encounters hard rock layers or uneven surfaces, when the cutting component 4 is subjected to a radial force pointing towards the axis of the core tube 1, the sealing component 5 is driven to perform synchronous centripetal deflection through the linkage plate 8. The radial force drives the cutting component 4 to move inward, which can actively avoid the non-uniform force area of ​​the uneven hard block at the top.

[0054] In use, after the detector transports the core sampler 1 to the sampling position and inserts it into the sand and gravel surface (since the surface is dusty and the bottom is hard rock), when the bottom of the core sampler 1 moves to the top of the hard rock layer, the servo motor 9 is activated. The servo motor 9 drives the support rod 6 and the cutting assembly 4 to slide along the inner side of the support frame 2. Simultaneously, the support frame 2 and the core sampler 1 are coaxially arranged, causing the cutting assembly 4 to move around the outer wall of the core sampler 1. The cutting assembly 4 is then activated, separating the rock mass covered by the core sampler 1 from the surrounding rock mass. When there is material higher than the rock mass or the rock surface is uneven, the cutting component 4, upon contact with this type of rock mass, exerts a radial force on the cutting component 4 pointing towards the axis of the core cylinder 1. This causes the cutting component 4 and the sealing component 5 to rotate around the central axis of the rotating shaft 7, bringing them closer together. During the cutting process, the inward convergence of the cutting component 4 actively avoids the uneven, hardened area at the top, reducing the risk of the drill bit 43 getting stuck. As the cutting depth of the cutting component 4 increases, it moves downward along the axis of the core cylinder 1. During this process, the rock moves upward relative to the cutting component 4, causing the rotation fulcrum of the cutting component 4 to gradually move upward, and its rotation angle gradually increases. This mechanism allows the sealing component 5 to be triggered and closed before the rock is higher than the cutting component 4, effectively reducing the interference between the cutting component 4 and the rock during its revolution. When hard rocks appear at the bottom of the core cylinder 1, it indicates an increased complexity of the bottom sample structure. At this point, ending the sampling operation early can reduce the risk of losing samples that have already entered the core cylinder 1.

[0055] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 7 , Figure 8 and Figure 9 The sealing assembly 5 includes a flexible cylinder 3, triangular plates 51, a groove 52, and magnets 53. The flexible cylinder 3 is slidably disposed at the bottom of the core-taking cylinder 1, and the groove 52 is fixed to the outer wall of the bottom of the flexible cylinder 3. Multiple triangular plates 51 are evenly distributed around the bottom end of the flexible cylinder 3, and magnets 53 are fixed to the inner walls of the multiple triangular plates 51. The triangular plates 51 are sewn to the flexible cylinder 3 through a flexible connecting layer 511, and the upper edge of the triangular plates 51 is tangent to the inner wall of the flexible cylinder 3. When the cutting assembly 4 is subjected to radial force, the flexible connecting layer 511 is pushed to produce elastic deformation through the linkage plate 8, driving the triangular plates 51 to deflect centripetally around the upper sewn joint, causing the multiple triangular plates 51 to converge inward and close. During the convergence process, the cutting assembly 4 reduces the diameter of the cylindrical tube connecting the bottom of the sample to the rock mass. When the magnets 53 attract each other, the magnetic force can be used to clamp the cylindrical tube connecting the bottom of the sample to the rock mass, and the magnets 53 attract each other to maintain the closed state, forming a bottom sealing structure.

[0056] To ensure that the bottom of the triangular plate 51 can close after the inner diameter decreases, and to prevent the triangular plate 51 from quickly returning to a vertical position, when the cutting component 4 is tilted, the bottom of the drill hole is tilted. At this time, the lower end of the triangular plate 51 abuts against the inner wall of the bottom of the drill hole, thereby limiting the angle after the triangular plate 51 returns to its original position. At the same time, when the adjacent triangular plates 51 bend, the magnets 53 at the ends of the adjacent triangular plates 51 exert a pulling force on the triangular plate 51 about to return to its original position towards the central axis of the core tube 1 through magnetic force when the distance between the adjacent triangular plates 51 and the magnets 53 at the ends of the triangular plates 51 about to return to their original position is the smallest. This limits the return of the triangular plates 51 from being too fast. The greater the tilt angle of the cutting component 4, the greater the magnetic force between the adjacent triangular plates 51. As the magnetic force increases, the diameter of the sample bottom decreases, and the strength of the sample bottom weakens.

[0057] Please refer to Figure 8 A flexible connecting layer 511 is sewn onto the outer side of each triangular plate 51. The flexible connecting layer 511 on the upper side of the triangular plate 51 is sewn onto the outer side of the covering layer 32 at the bottom of the flexible cylinder 3. The flexible connecting layer 511 is made of glass fiber, Vectran fiber, or other textiles. This allows the flexible connecting layer 511 to elastically deform when the triangular plate 51 is subjected to radial force, even when the sample itself has a low weight and loose structure. This causes the triangular plate 51 to rotate centripetally around its junction with the flexible cylinder 3. The deflection motion causes the sample to converge inward. After the triangular plate 51 converges inward, the weight of the sample is applied to the inner wall of the triangular plate 51. When the sample itself has a low weight and a loose structure, the sand and dust inside the core tube 1 are in a floating state and exert less pressure on the triangular plate 51. This results in less resistance to the triangular plate 51 from the sample inside the core tube 1 compared to a sample with a higher density and greater weight. The contact pressure with the sand and gravel can be dynamically adjusted, and the sample can deform in coordination with the cutting component 4 to accurately avoid obstacles.

[0058] When the core sample reaches the target location, the active drive component 4 deflects, and the linkage plate 8 causes the triangles to bend inward in sequence, resulting in a continuous reduction in the bottom diameter of the core sample. At the same time, the connection strength between the core sample and the rock mass gradually weakens. Due to the low gravity and loose structure of the sample itself, when the mutual attraction between the magnets 53 can clamp the core sample, the magnets 53 attract each other, causing multiple triangles 51 to stick together at the bottom of the flexible cylinder 3 and close the bottom of the flexible cylinder 3. Under the influence of gravity, the core sample inside the flexible cylinder 3 exerts a large downward pressure on the connection where the diameter is reduced, causing it to break prematurely due to gravity before the diameter is reduced to the point where the mutual attraction between the magnets 53 can clamp it. This greatly increases the resistance when multiple triangles 51 stick together, making it easy to cause problems with loose adhesion. At the same time, the fragments cut at the contact point between the inner wall of the core sampling cylinder 1 and the rock mass sample move downward under the influence of gravity and accumulate at the bottom of the rock mass, which will also affect the closure of multiple sealing plates.

[0059] Please refer to Figures 2 to 3 The flexible cylinder 3 includes a braided layer 31 and a covering layer 32. The braided layer 31 is formed by weaving multiple stainless steel wires in a grid arrangement to form an axially reinforced structure. The covering layer 32 covers the outer surface of the braided layer 31, and its outer edge wall is welded and fixed to the groove 52.

[0060] The mesh-arranged metal wire mesh forms a continuous force transmission path in the axial direction, while absorbing impact energy in the radial direction through mesh deformation, making it suitable for both rigid drilling and flexible obstacle avoidance in sand and gravel sampling.

[0061] This gives the flexible cylinder 3 good rigidity and strength, while allowing it to deform during obstacle avoidance to improve the adaptability of the device. It provides rigid support for the rock core sample while also having good flexibility, allowing it to deform slightly during obstacle avoidance to facilitate the flexible cylinder 3 passing through harder rock masses.

[0062] Please refer to Figure 4 and Figure 5 The cutting assembly 4 includes a rotating seat 41, a micro motor 42, and a drill bit 43. The rotating seat 41 is rotatably connected to the inner side of the rotating shaft 7, and the micro motor 42 is fixed at the lower end of the rotating seat 41. The output end of the micro motor 42 is connected to the drill bit 43.

[0063] Two rotating parts 411 are provided on the upper end face of the rotating seat 41, and the central axes of the two rotating parts 411 are arranged in parallel. The height of the end of the drill bit 43 is lower than the height of the lower end of the triangular plate 51, so that the drill bit 43 contacts the rock mass first. The design that the end of the drill bit 43 is lower than the triangular plate 51 ensures that the drill bit 43 contacts the sand and gravel rock mass first, forming an initial cutting guide surface, which helps to reduce the wear of the bottom triangular plate 51 of the sealing component 5. At the same time, it can also reduce the interference between the drill bit 43 and the triangular plate 51 when the drill bit 43 rotates. The end of the drill bit 43 is fixedly provided with a sharp part 431. When the sharp part 431 moves around the core tube 1 for cutting, the inner diameter of its cutting trajectory is smaller than the inner diameter of the core tube 1. During the cutting operation, the drill bit 43 revolves around the axis of the core tube 1, while the sharp part 431 rotates around its own axis to cut the sample at its bottom. Because the inner diameter of the orbital cutting trajectory of the sharp part 431 is smaller than the inner diameter of the core tube 1, the cut sample can be completely wrapped by the sealing component 5. The sharp part 431 has a conical structure design.

[0064] When cutting hard blocks with high hardness, if the upper surface of the block is flat, the force between the central axis of the tip 431 and the rock mass is transmitted in the vertical direction, which facilitates drilling the block. When the upper surface of the block is inclined or uneven, the block applies a component force perpendicular to the inclined surface to the tip 431. At this time, the tip 431 of the conical structure can tilt along the direction of the component force to adapt to the surface shape of the block and deflect.

[0065] In use, the shaft 7 at the bottom of the support rod 6 is connected to the rotating part 411 at the upper end of the rotating seat 41 near the core cylinder 1. During normal drilling, the force between the lower end face of the drill bit 43 and the rock mass is in the same vertical direction, which enables drilling of the rock mass. The drill bit 43 cuts around the outer wall of the core cylinder 1 to separate the sample from the surrounding sample. If it is necessary to increase the diameter of the core sample in the future, the core cylinder 1 with a larger diameter can be replaced. Compared with replacing the drilling tool assembly, this improves the convenience of the device and reduces costs.

[0066] At the same time, using the circumferential cutting method can maintain a relatively complete layered structure in the middle of the core sample, which helps to reduce stress concentration.

[0067] Please refer to Figures 1 to 3A servo motor 9 is fixed to the top of the core-taking cylinder 1, and a connecting rod 10 is fixed to the output end of the servo motor 9. The end of the connecting rod 10 away from the servo motor 9 is fixedly connected to the upper end of the support rod 6. A guide groove 11 is fixed to the outside of the core-taking cylinder 1, and the guide groove 11 is spiral in shape. A sleeve 12 is slidably arranged on the outside of the support rod 6, and a guide block 13 is fixed to the outside of the sleeve 12. The shape of the guide block 13 matches the groove opening in the guide groove 11, and the movement path of the guide block 13 is the same as the path of the guide groove 11. When the servo motor 9 rotates, it drives the support rod 6 to rotate along the support frame 2 via the connecting rod 10. The support rod 6 cuts the rock mass around the side wall of the core cylinder 1 with the central axis of the core cylinder 1 as the center, so that the sample at the bottom of the core cylinder 1 is cut and separated from the surrounding rock mass. At the same time, during the rotation of the support rod 6, the sleeve 12 and the guide block 13 slide along the guide groove 11. The guide block 13 and the sleeve 12 are fixedly connected, so that as the support rod 6 rotates, the sleeve 12 moves downward to facilitate penetration into deeper layers of rock. This not only ensures stable autonomous feeding and deep sampling capabilities when the sample itself has low gravity and loose structure, but also reduces the weight and energy consumption of the equipment through structural simplification.

[0068] Please refer to Figure 4 The linkage plate 8 includes a protective plate 81 and a guide rod 82. The protective plate 81 is fixed between the micro motor 42 and the core-taking cylinder 1. The protective plate 81 is arc-shaped, and the middle part of the protective plate 81 protrudes towards the side close to the flexible cylinder 3, so that the protrusion contacts the outer wall of the triangular plate 51. The guide rod 82 is fixed to the outer wall of the protective plate 81. In order to avoid motion interference between the protective plate 81 and the guide rod 82 when the protective plate 81 rotates, the guide rod 82 is designed to be telescopic, which helps to reduce stress concentration on the guide rod 82 when the cutting assembly 4 rotates.

[0069] Please refer to Figure 4 A spherical plug 821 is fixed to the end of the guide rod 82. The volume of the spherical plug 821 is adapted to the slide groove 52. The linkage plate 8 is fixed to the outer wall of the micro motor 42.

[0070] When the cutting assembly 4 rotates, it causes the protective plate 81 to rotate towards the side closer to the triangular plate 51. At this time, the protrusion on the outer wall of the protective plate 81 presses the triangular plate 51 in contact with it, bending it inward to prevent motion interference between the drill bit 43 and the triangular plate 51. This is beneficial to the synchronization between the drill bit 43 and the corresponding triangular plate 51. At the same time, since the protective plate 81 and the triangular plate 51 are not fixedly connected, when the drill bit 43 contacts another triangular plate 51, the edge of the protective plate 81 contacts the edge of the triangular plate 51 first. As the position of the drill bit 43 changes, the edge of the triangular plate 51 gradually protrudes from the edge of the arc surface towards the center of the arc surface. The gradual cutting in helps reduce the rigid pressure when the two collide directly and protects the cutting component 4. At the same time, the guide rod 82 provides a force point for the cutting component 4, which helps increase the stability between the flexible cylinder 3 and the cutting component 4. Since the end of the guide rod 82 is spherical and the inner side of the slide groove 52 is also arc-shaped, when the cutting component 4 and the guide rod 82 rotate, the guide rod 82 can rotate slightly up and down inside the slide groove 52. When the cutting component 4 tilts, the guide rod 82 has a suitable range of motion inside the slide groove 52, reducing the motion interference between the guide rod 82 and the slide groove 52.

[0071] Please refer to Figure 5 A piston rod 14 is rotatably connected to the upper end of another rotating part 411 on the rotating seat 41, and a hollow rod 15 is slidably provided on the outer side of the piston rod 14. An electric telescopic rod 16 is fixed to the upper end of the hollow rod 15. Damping fluid is filled between the output end of the electric telescopic rod 16 and the piston rod 14. The two ends of the return spring 17 are fixedly connected to the lower end face of the piston rod 14 and the bottom wall of the inner cavity of the hollow rod 15, respectively.

[0072] In use, when the cutting assembly 4 is subjected to a radial force pointing towards the axis of the core barrel 1, and this force is greater than the elastic force of the return spring 17, the return spring 17 undergoes elastic deformation. After the cutting assembly 4 passes around the hard rock, the deformation restoring force of the return spring 17 is used to correct the cutting assembly 4, making the central axis of the drill bit 43 parallel to the core barrel 1. When the core taking is completed, the electric telescopic rod 16 is activated, and the output end of the electric telescopic rod 16 extends downward and then contacts the damping fluid. By pushing the damping fluid and the piston rod 14, it moves towards... The piston rod 14 moves downward, thereby pressing the rotating seat 41 to rotate around the rotating shaft 7. Then, the piston rod 14 is closed by the mutual attraction of the magnets 53 on the triangular plate 51 and the bottom of the core tube 1 is closed. This is driven by the electric telescopic rod 16. Before the electric telescopic rod 16 extends, the distance between the end of the electric telescopic rod 16 and the damping fluid provides conditions for the piston rod 14 to move freely up and down. The electric telescopic rod 16 causes the cutting component 4 to deflect inward and the sealing component 5 to close, so that the volume of the core sample can be temporarily and dynamically adjusted according to the task requirements.

[0073] The following description, in conjunction with the accompanying drawings and embodiments, further illustrates a trigger-type variable diameter rock coring device and coring method provided by the present invention.

[0074] S1. When in use, after transporting the core tube 1 to the sampling position, start the servo motor 9. The servo motor 9 drives the support rod 6 to rotate in a circle along the support frame 2, which will clear away the loose sand on the surface of the sand and gravel around the core tube 1, making it easier for the core tube 1 to be inserted into the sand until the lower end of the core tube 1 reaches the upper end of the hard rock mass.

[0075] S2. Simultaneously, when the guide block 13 on the sleeve 12 slides along the guide groove 11, it drives the sleeve 12, the cutting component 4 and the flexible cylinder 3 to move downward synchronously. When the sand outside the gravel is thick, it can increase the internal space of the core tube 1 to accommodate more samples.

[0076] S3. When a small, hard rock is encountered around the core barrel 1, and one corner of the rock is inside the core barrel 1, the rock exerts a radial force on the drill bit 43 pointing towards the axis of the core barrel 1. This causes the drill bit 43 and the cutting assembly 4 to deflect away from the rock around the pivot 7, thus avoiding the corner of the rock extending into the core barrel 1 and facilitating the core barrel 1 to continue to penetrate deeper. After the cutting assembly 4 passes around the rock, the rock presses the flexible cylinder 3, causing the flexible cylinder 3 to deform inward and reduce interference with the rock. At the same time, the core taking stops after passing around the rock and before the rock is lower than the rotating seat 41.

[0077] S4. Simultaneously, when the cutting component 4 deflects, it drives the linkage plate 8 to rotate synchronously. When the linkage plate 8 rotates, it drives the guide rod 82 to rotate along the spherical plug 821. The edge of the triangular plate 51 gradually cuts into the center of the arc surface along the edge of the arc surface. The protective plate 81 pushes the triangular plate 51 in contact with the protective plate 81 to rotate inward, and performs an inward convergence action synchronously with the cutting component 4, so that the diameter of the rock mass inside the core tube 1 changes.

[0078] S5. When sampling is completed or the staff believes that the bottom environment is too complex to continue sampling, the electric telescopic rod 16 is extended downward by controlling it, thereby driving the piston rod 14 inside the hollow rod 15 to move downward and press the rotating seat 41 to rotate around the rotating shaft 7, thereby actively cutting the sample at the bottom of the core tube 1. At this time, the movement path of the cutting component 4 is still circular, so that the connection shape between the bottom of the sample and the rock is a cylindrical tube. As the inclination angle of the cutting component 4 increases, the diameter of the cylindrical tube connecting the bottom of the sample and the rock decreases, and the connection strength between the sample and the bottom rock decreases.

[0079] S6. When the space at the bottom of the core tube 1 increases due to the stone extending into it, the angle of the cutting component 4 increases, and the distance between the magnets 53 on the multiple triangular plates 51 decreases. When the attraction of the magnets 53 is greater than the bonding force between the sample and the rock, the multiple magnets 53 attract each other and cut the sample from the rock. After the magnets 53 stick together, the bottom of the core tube 1 forms a relatively sealed and closed state, thus enabling the core taking to end in advance.

[0080] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0081] The foregoing has shown and described the basic principles, main features, and advantages of this disclosure. Those skilled in the art should understand that this disclosure is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this disclosure. Various changes and modifications can be made to this disclosure without departing from its spirit and scope, and all such changes and modifications fall within the scope of this disclosure as claimed.

Claims

1. A trigger-type variable diameter rock coring device, characterized in that, include: Core-taking cylinder (1), cutting assembly (4), and sealing assembly (5); The outer wall of the core sampling cylinder (1) is provided with a support frame (2), and a flexible cylinder (3) is slidably connected to the bottom of the core sampling cylinder (1), and a sealing component (5) is fixed to the bottom of the flexible cylinder (3). A support rod (6) is slidably provided on the inner side of the support frame (2). The bottom of the support rod (6) is rotatably connected to a cutting assembly (4) via a rotating shaft (7). The working surface of the cutting assembly (4) is parallel to and axially aligned with the sealing end face of the sealing assembly (5). The axis of the rotating shaft (7) is perpendicular to the axis of the core-taking cylinder (1), and a linkage plate (8) is provided between the cutting assembly (4) and the sealing assembly (5); When the cutting component (4) encounters a hard rock layer or an uneven surface, the cutting component (4) is subjected to a radial force pointing towards the axis of the core tube (1). The sealing component (5) is driven to perform synchronous centripetal deflection through the linkage plate (8). The radial force drives the cutting component (4) to move inward to actively avoid the non-uniform force area of ​​the uneven hard block at the top.

2. The trigger-type variable diameter rock coring device according to claim 1, characterized in that, The sealing assembly (5) includes a flexible cylinder (3), a triangular plate (51), a groove (52), and a magnet (53). The flexible cylinder (3) is slidably disposed at the bottom of the core-taking cylinder (1), and the groove (52) is fixed on the outer wall of the bottom of the flexible cylinder (3). Multiple triangular plates (51) are evenly distributed around the bottom end of the flexible cylinder (3), and magnets (53) are fixed on the inner walls of the multiple triangular plates (51). The triangular plates (51) are sewn to the flexible cylinder (3) through a flexible connecting layer (511), and the upper edge of the triangular plate (51) is tangent to the inner wall of the flexible cylinder (3).

3. The trigger-type variable diameter rock coring device according to claim 2, characterized in that, The flexible cylinder (3) includes a braided layer (31) and a covering layer (32). The braided layer (31) is woven from multiple stainless steel wires in a grid arrangement to form an axially reinforced structure. The covering layer (32) covers the outer surface of the braided layer (31), and its outer edge wall is welded and fixed to the groove (52).

4. The trigger-type variable diameter rock coring device according to claim 1, characterized in that, The cutting assembly (4) includes a rotating seat (41), a micro motor (42) and a drill bit (43). The rotating seat (41) is rotatably connected to the inner side of the rotating shaft (7), and the micro motor (42) is fixed at the lower end of the rotating seat (41). The output end of the micro motor (42) is connected to the drill bit (43).

5. A trigger-type variable diameter rock coring device according to claim 4, characterized in that, The upper end face of the rotating seat (41) is provided with two rotating parts (411), and the central axes of the two rotating parts (411) are arranged in parallel. The height of the end of the drill bit (43) is lower than the height of the lower end of the triangular plate (51), so that the drill bit (43) contacts the rock first. The end of the drill bit (43) is fixedly provided with a sharp part (431). When the sharp part (431) moves around the core tube (1) for cutting, the inner diameter of the cutting trajectory of the sharp part (431) is smaller than the inner diameter of the core tube (1). During the cutting operation, the drill bit (43) revolves around the axis of the core cylinder (1), while the pointed part (431) rotates around its own axis to cut the sample at its bottom. The pointed part (431) has a conical structure design.

6. The trigger-type variable diameter rock coring device according to claim 1, characterized in that, A servo motor (9) is fixed to the top of the core-taking cylinder (1), and a connecting rod (10) is fixed to the output end of the servo motor (9). The end of the connecting rod (10) away from the servo motor (9) is fixedly connected to the upper end of the support rod (6). A guide groove (11) is fixed to the outside of the core-taking cylinder (1), and the guide groove (11) is spiral in shape. A sleeve (12) is slidably arranged on the outside of the support rod (6), and a guide block (13) is fixed to the outside of the sleeve (12). The shape of the guide block (13) matches the groove in the guide groove (11), and the moving path of the guide block (13) is the same as the path of the guide groove (11).

7. A trigger-type variable diameter rock coring device according to claim 4, characterized in that, The linkage plate (8) includes a protective plate (81) and a guide rod (82). The protective plate (81) is fixed between the micro motor (42) and the core tube (1). The protective plate (81) is arc-shaped, and the middle part of the protective plate (81) protrudes towards the side close to the flexible tube (3), so that the protrusion contacts the outer wall of the triangular plate (51). The guide rod (82) is fixed to the outer wall of the protective plate (81).

8. A trigger-type variable diameter rock coring device according to claim 7, characterized in that, The end of the guide rod (82) is fixed with a spherical plug (821), the volume of which is adapted to the slide groove (52), and the linkage plate (8) is fixed to the outer wall of the micro motor (42).

9. A trigger-type variable diameter rock coring device according to claim 5, characterized in that, A piston rod (14) is rotatably connected to the upper end of another rotating part (411) on the rotating seat (41), and a hollow rod (15) is slidably provided on the outer side of the piston rod (14), and an electric telescopic rod (16) is fixed to the upper end of the hollow rod (15). Damping fluid is filled between the output end of the electric telescopic rod (16) and the piston rod (14), and the two ends of the return spring (17) are fixedly connected to the lower end face of the piston rod (14) and the bottom wall of the inner cavity of the hollow rod (15), respectively.

10. A method for core sampling of rocks, using a trigger-type variable-diameter rock core sampling device as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. When in use, after transporting the core tube (1) to the sampling position, start the servo motor (9). The servo motor (9) drives the support rod (6) to rotate in a circle along the support frame (2), which will remove the loose sand on the surface of the sand and gravel around the core tube (1) so that the core tube (1) can be inserted into the sand until the lower end of the core tube (1) reaches the upper end of the hard rock mass. S2. At the same time, when the guide block (13) on the sleeve (12) slides along the guide groove (11), it drives the sleeve (12), the cutting component (4) and the flexible cylinder (3) to move downward synchronously. In the case of thick sand on the outside of the sand and gravel, it can increase the internal space of the core tube (1) to accommodate more samples. S3. When hard rocks are encountered around the core barrel (1), the rocks exert a radial force on the drill bit (43) pointing towards the axis of the core barrel (1), thereby causing the drill bit (43) and the cutting assembly (4) to deflect away from the rocks with the pivot (7) as the center. S4. When the cutting component (4) deflects, it drives the linkage plate (8) to rotate synchronously. When the linkage plate (8) rotates, it drives the guide rod (82) to rotate along the spherical plug (821). The edge of the triangular plate (51) gradually cuts into the center of the arc surface along the edge of the arc surface. The triangular plate (51) in contact with the protective plate (81) is pushed to rotate inward through the protective plate (81). It moves inward in sync with the cutting component (4), causing the diameter of the rock mass inside the core tube (1) to change. S5. After sampling is completed, the electric telescopic rod (16) is extended downward by remote control, thereby driving the piston rod (14) inside the hollow rod (15) to move downward and press the rotating seat (41) to rotate around the rotating shaft (7) as the center, thereby actively cutting the sample at the bottom of the core tube 1. At this time, the movement path of the cutting component (4) is still circular, so that the connection shape between the bottom of the sample and the rock is a cylindrical tube. As the inclination angle of the cutting component (4) increases, the diameter of the cylindrical tube connecting the bottom of the sample and the rock shrinks, and the connection strength between the sample and the bottom rock is reduced. S6. When the tilt angle of the cutting component (4) increases, the distance between the magnets (53) on the multiple triangular plates (51) decreases. When the attraction of the magnets (53) is greater than the connection strength between the sample and the rock mass, the multiple magnets (53) attract each other and cut the sample and the rock mass. After the magnets (53) are attached together, the bottom of the core tube (1) forms a relatively sealed and closed state, thereby completing the core taking.

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