Micro core fine machining grinding device and core preparation method

Abstract

The invention relates to the technical field of sampling, in particular to a micro rock core fine machining grinding device and a rock core preparation method.The micro rock core fine machining grinding device comprises a clamping module and a power module, the clamping module comprises a chuck and a clamping jaw movably arranged on the end face of the chuck, and the clamping jaw is used for clamping one end of a rock core sample; the clamping module further comprises three sanding rollers which are uniformly arranged on the periphery of the clamping jaw at intervals, the peripheries of the three sanding rollers are used for clamping a rock core sample and polishing the peripheral surface of the rock core sample, and the power module is used for being in transmission connection with the three sanding rollers and driving the sanding rollers to rotate so as to polish the periphery of the rock core sample; clutch can be achieved between the power module and the three sanding rollers. The technical problems that in the prior art, rock core samples are prone to fracture in the polishing process, and the scanning precision is affected due to the fact that the polished rock core samples are large in diameter are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of sampling, and in particular to a micro core fine processing and grinding device and a core preparation method. Background Art

[0002] During oil exploration and development, formation rock samples are often drilled and cores of varying sizes are prepared for analysis of reservoir mineral composition and petrophysical properties. CT scanning core analysis is a recently developed technique that digitally reconstructs the three-dimensional structural characteristics of pore throats through scanned images. Reservoir microscopic pore structure analysis and seepage simulations are then performed based on this reconstructed data. The resolution of CT scanning is directly dependent on sample size. The smaller the core sample diameter, the higher the scanning accuracy, meaning the finer the pore throat structure that can be resolved.

[0003] Existing micro-core preparation devices or methods are prone to brittleness and breakage during the millimeter-scale micro-core preparation process, or their dimensions, specifications, and shape profiles do not meet the requirements of core CT scanning. For example, Chinese invention patent application publication number CN115056091A discloses a micro-core sample grinding device, which includes a chuck, an ejector pin, and a diamond grinding disc. The rock sample is clamped and fixed between the chuck and the ejector pin. The chuck rotates, driving the rock sample, while the diamond grinding disc grinds the rock sample from one side. Because the diameter of the polished rock sample is often relatively small and the rock sample is unsupported, grinding from one side of the rock sample with the diamond grinding disc is prone to fracture. Moreover, to avoid fracture, the polished rock sample often does not have a small enough diameter, which affects CT scanning accuracy. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention proposes a micro-core fine processing grinding device and a core preparation method to solve the technical problems in the existing technology that core samples are easily broken during the grinding process, and the diameter of the ground core samples is large, which affects the scanning accuracy.

[0005] The micro core fine processing grinding device and core preparation method of the present invention adopt the following technical solutions:

[0006] A micro core fine processing grinding device and a core preparation method, comprising a grinding platform and a clamping module arranged on the grinding platform, the clamping module comprising a chuck and a clamping jaw movably arranged on the end face of the chuck, the clamping jaw being used to clamp one end of the core sample, the clamping module further comprising three sanding rollers evenly spaced around the periphery of the clamping jaw, the three sanding rollers being parallel to each other and having axes extending in the left-right direction, the axis extension direction of the sanding roller being the same as the axis extension direction of the core sample clamped on the clamping jaw, the outer periphery of the three sanding rollers being used to clamp the core sample and grind the outer peripheral surface of the core sample, the chuck being provided with three sliding blocks movable along the radial direction of the chuck at the periphery of the clamping jaw, the three sliding blocks being evenly spaced around the circumference of the chuck, One end of the grinding roller is rotatably mounted on three sliding blocks. When the three sliding blocks approach each other radially along the chuck, they drive the three sanding rollers to approach each other to clamp the outer periphery of the core sample. A power module is also provided on the grinding platform. The power module is used to be connected to the three sanding rollers for transmission, and drive the sanding rollers to rotate to grind the outer periphery of the core sample. At least one of the power module and the clamping module can move in the left and right directions to achieve clutch between the power module and the three sanding rollers. When one end of the core sample is clamped by the chuck, the power module and the clamping module approach each other, and the power module is connected to the sanding roller for transmission. When the core sample needs to be removed, the power module and the clamping module are separated from each other, and the power module is disconnected from the sanding roller for transmission.

[0007] Furthermore, the power module includes a support frame, a rotary drive mechanism, a driving pulley and three transmission pulleys. The rotary drive mechanism is arranged on the support frame. The three transmission pulleys are arranged in an equilateral triangle and are arranged one-to-one with the three sanding rollers. The rotary drive mechanism is connected to the driving pulley, and the driving pulley is connected to the three transmission pulleys at the same time through the same transmission belt. When the power module and the clamping module approach each other, the end of each sanding roller away from the chuck is respectively inserted into and locked with one end of the corresponding transmission pulley. When the power module and the clamping module are separated from each other, the end of each sanding roller away from the chuck is respectively disconnected from the corresponding transmission pulley.

[0008] Furthermore, two of the three transmission pulleys have the same outer diameter, namely the first pulley and the second pulley, and the other one has an outer diameter larger than the first pulley and the second pulley, namely the third pulley. The first pulley and the second pulley are respectively located below the third pulley. When the active pulley drives the three transmission pulleys to rotate through the transmission belt, the rotation speed of the first pulley and the second pulley is greater than the rotation speed of the third pulley, so that the rotation speed of the sanding roller connected to the third pulley is less than the rotation speed of the sanding rollers connected to the first pulley and the second pulley respectively. When the three sanding rollers approach each other and clamp the core sample After the periphery of the core sample is reached, the clamping jaws release the clamping of the core sample, and the two sanding rollers respectively connected to the first pulley and the second pulley are used to drive the core sample to rotate, and the sanding roller connected to the third pulley rotates relative to the core sample to grind the core sample; the outer peripheral surfaces of the three sanding rollers are all provided with a grinding layer, the mesh sizes of the grinding layers of the three sanding rollers are all different, and the three sanding rollers have different grinding precisions for the core sample, and when the chuck is rotated, the circumferential positions of the three sanding rollers can be switched, so that the three sanding rollers are respectively connected to different drive pulleys.

[0009] Furthermore, the micro-core fine processing and grinding device includes a circumferentially closed isolation cabinet, and a middle partition is provided inside the isolation cabinet. The middle partition divides the internal space of the entire isolation cabinet into two upper and lower chambers. The upper chamber is the grinding chamber, and the upper side of the middle partition forms the grinding platform. The clamping module and the power module are arranged on the middle partition. The core sample to be ground is ground in the grinding chamber. The chamber below the middle partition is the dust suction chamber. A vacuum cleaner is provided in the dust suction chamber. A dust baffle is provided on one side of the power module. A dust suction port is opened on the dust baffle. The vacuum cleaner is connected to the dust suction port on the dust baffle through a dust suction pipe. When the core sample is ground, the dust suction port faces one side of the core sample to suck debris on the surface of the core sample.

[0010] Furthermore, the power module includes a deformable bracket, which includes three connecting shafts. The axes of the three connecting shafts extend in the left-right direction and are arranged one-to-one with the three sanding rollers. The three transmission pulleys are rotatably installed on the end of each connecting shaft facing the sanding roller. A guide link is connected between each two adjacent connecting shafts. One end of the guide link is fixedly connected to one of the two adjacent connecting shafts, and the other end is movably inserted in the other connecting shaft. The three guide links form an equilateral triangle structure. Each guide link is provided with a first compression spring, which presses between the two adjacent connecting shafts to make the three connecting shafts stay away from each other in the initial state.

[0011] Furthermore, the power module also includes a conical cylinder movably arranged on the support frame along the left and right directions, the axis of the conical cylinder extends along the left and right directions, and one end of the conical cylinder is a flared end, and the other end is a closed end, the flared end of the conical cylinder faces the chuck, and a dovetail groove extending along the busbar of the conical cylinder is provided on the inner wall of the conical cylinder, and three dovetail grooves are evenly spaced along the circumference of the conical cylinder, and a dovetail block is fixed at one end of the three connecting shafts away from the transmission pulley, and each dovetail block is slidably installed in the corresponding dovetail groove. When the conical cylinder moves along the left and right directions relative to the support frame, the dovetail block moves along the extension direction of the dovetail groove, so that the three connecting shafts approach or move away from each other along the radial direction of the conical cylinder.

[0012] Furthermore, the support frame includes a vertical frame and a support shaft cantilevered on the vertical frame along the left and right directions. The conical cylinder is movably mounted on the support shaft along the left and right directions. The three connecting shafts and three guide connecting rods are respectively located on the periphery of the support shaft. The power module also includes a telescopic drive mechanism. The telescopic drive mechanism has a telescopic shaft extending along the left and right directions. When the telescopic shaft is extended, it pushes the conical cylinder toward the direction close to the chuck, so that the three connecting shafts approach each other along the radial direction of the conical cylinder.

[0013] Furthermore, a push ring is provided on the vertical frame along the left and right directions, one end of the push ring is in push contact with the closed end of the conical tube, and the other end is in push contact with the telescopic shaft. An axial tension spring is connected between the closed end of the conical tube and the vertical frame, one end of the axial tension spring is connected to the closed end of the conical tube, and the other end is connected to the vertical frame. When the telescopic shaft is shortened, the axial tension spring drives the conical tube to move away from the chuck, and the first compression spring drives the three connecting shafts to move away from each other along the radial direction of the conical tube.

[0014] Furthermore, the pushing ring is composed of a plurality of guide rods and two circular rings arranged symmetrically on the left and right sides. The left and right circular rings are respectively located on the left and right sides of the vertical frame. The plurality of guide rods extend in the left and right directions and are evenly spaced along the circumference of the support shaft. The two ends of each guide rod are fixedly connected to the circular rings on the left and right sides respectively. Each guide rod is guided and passed through the vertical frame along the left and right directions. One of the left and right circular rings is in pushing contact with the closing end of the conical cylinder, and the other is in pushing contact with the telescopic shaft of the telescopic drive mechanism.

[0015] Furthermore, the deformable bracket also includes a triangular plate, a through hole is provided in the center of the triangular plate, the triangular plate is installed on the support shaft through the through hole, three guide grooves extending radially along the through hole are provided on the periphery of the through hole of the triangular plate, the guide grooves are arranged in a one-to-one correspondence with the connecting shafts, and each connecting shaft is respectively passed through the corresponding guide grooves, and the side walls of the connecting shaft are provided with a card groove that cooperates with the side wall of the triangular plate to stop the triangular plate, and the card groove prevents the triangular plate from moving axially along the connecting shaft.

[0016] Furthermore, the support shaft is movably arranged on the stand in the left and right directions, and a second compression spring is sleeved on the support shaft. The second compression spring is located inside the conical cylinder, and one end of the second compression spring contacts the inner wall of the closing end of the conical cylinder. A shaft shoulder is provided on the side wall of the support shaft, and the other end of the second compression spring contacts the shaft shoulder. When the conical cylinder moves toward the chuck, the conical cylinder drives the support shaft to move toward the chuck through the second compression spring, so that the end of the support shaft toward the chuck fits with the end of the core sample to prevent the core sample from moving toward the conical cylinder.

[0017] Furthermore, the support frame includes a limit bracket and a lifting frame movably arranged in the limit bracket along the upper and lower directions, the limit bracket and the lifting frame are located below the transmission belt pulley, and a lifting drive mechanism is provided below the lifting frame, the rotary driving mechanism is arranged on the lifting frame, the active belt pulley is rotatably installed on the lifting frame, and the lifting frame adjusts the tension of the transmission belt when it moves up and down. When the transmission belt pulley is separated from the sand grinding roller, the lifting frame rises to loosen the transmission belt, and the transmission belt is separated from each transmission belt pulley. When the three sand grinding rollers approach each other and clamp the core sample, the lifting frame descends to tighten the transmission belt and fit closely with each transmission belt pulley. Tensioning wheels are respectively rotatably provided on the limit bracket on opposite sides of the transmission belt, and the two tensioning wheels are respectively located above the active belt pulley, and the distance between the two tensioning wheels is smaller than the outer diameter of the active belt pulley.

[0018] Furthermore, a limiting ring is fixed on the periphery of the clamping jaws of the chuck, and three sliding grooves extending along its own radial direction are provided at circumferential intervals. The sliding blocks are respectively guided and installed in the corresponding sliding grooves, and a radial tension spring is respectively provided in each sliding groove. One end of the radial tension spring is fixedly connected to the sliding block, and the other end is fixedly connected to the limiting ring. When each sanding roller is separated from the transmission pulley, each radial tension spring drives the sliding blocks to move away from each other along the radial direction of the limiting ring, so that the three sanding rollers are away from each other.

[0019] Furthermore, the polishing platform is provided with a transverse slide rail extending in the left and right directions and a longitudinal slide rail extending in the front and back directions. The transverse slide rail is guided by a transverse slide that moves in the left and right directions, and the longitudinal slide rail is guided by a longitudinal slide that moves in the front and back directions. The clamping module is arranged on the transverse slide, and the power module is arranged on the longitudinal slide. The transverse slide moves left and right to drive the clamping module close to or away from the power module, and the longitudinal slide moves forward and backward to drive the power module to be staggered or aligned with the clamping module in the front and back directions.

[0020] A core preparation method using the micro core fine processing grinding device comprises the following steps:

[0021] a. Prepare core samples: Select an initial core sample that meets the length requirements, then perform CT scanning on the initial core sample to select the target area, and use a wire cutting tool to cut the portion of the initial core sample containing the target area into a cylindrical core sample, with both ends of the core sample having flat end surfaces;

[0022] b. Grinding the core sample for the first time; insert the columnar core sample between the three sanding rollers of the clamping module, clamp one end of the core sample with the clamping claw, fix the core sample on the chuck, and the clamping module and the power module are close to each other and connected in transmission. The three sanding rollers are close to each other and clamp the outer periphery of the core sample. The power module drives the sanding rollers to rotate to grind the outer periphery of the core module; use sanding rollers with a grinding layer of 800 mesh to grind the core sample, set the speed of the rotary drive mechanism to 3000 rpm, and extend the telescopic rod of the telescopic drive mechanism at a set speed to extend the tapered cylinder at a set speed toward the chuck, so that the three sanding rollers approach the core sample along the radial direction of the core sample at a feed speed of 0.05 mm / min, that is, the feed speed of the sanding rollers is 0.05 mm / min, and the grinding feed amount of the entire first grinding is 2 mm;

[0023] c. Grind the core sample a second time; use a sanding roller with a grinding layer of 1200 mesh to grind the core sample, set the speed of the rotary drive motor to 2000 rpm, the grinding feed of the sanding roller to 2 mm, and the feed rate to 0.02 mm / min;

[0024] d. Grind the core sample for the third time; use a sanding roller with a grinding layer of 2000 mesh to grind the core sample, set the speed of the rotary drive motor to 2000 rpm, the grinding feed of the sanding roller 38 to 1 mm, and the feed speed to 0.01 mm / min.

[0025] The beneficial effects of the present invention are as follows: a micro-core fine processing and grinding device and a core preparation method of the present invention are provided. The micro-core fine processing and grinding device arranges sanding rollers parallel to the axis of the core sample around the core sample, and uses the sanding rollers to support and grind the core sample. This can protect the core sample and prevent it from breaking during the grinding process. This allows the core sample to be ground more times, and a core sample with a smaller diameter can be obtained. Furthermore, by setting the grinding layer mesh of the three sanding rollers to different sizes and switching between different sanding rollers to grind the core sample, the grinding efficiency can be improved, and the use is more convenient.

[0026] The present invention utilizes a vacuum cleaner to suck the surface of the core sample from one side of the core sample, which can, on the one hand, peel off debris from the surface of the core sample, and on the other hand, solve the heat accumulation during the grinding of the core sample surface through air cooling. In addition, in terms of HSE, dust diffusion is controlled to ensure the health and safety of the operating environment of the workers.

[0027] The core sample prepared by the core preparation method of the present invention has a scanning voxel accuracy of 1.743 μm in a micron CT system. During the core preparation process, manual operation is required only in the steps of adjusting the grinding parameters and replacing the grinding head. No human supervision is required in the rest of the processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work. Those skilled in the art should understand that these drawings are not necessarily drawn to scale.

[0029] Figure 1 It is an overall three-dimensional schematic diagram of an embodiment of a micro-core fine processing and grinding device of the present invention;

[0030] Figure 2 This is a schematic diagram of an embodiment of a micro-core fine processing and grinding device of the present invention, after removing the isolation cabinet and the vacuum cleaner;

[0031] Figure 3 This is a schematic diagram of the docking of a power module and a clamping module in one embodiment of a micro core fine machining and grinding device of the present invention (the power module is without the outer shell);

[0032] Figure 4 This is a schematic diagram of a micro-core fine processing and grinding device according to an embodiment of the present invention, wherein the power module and the clamping module are separated (the power module is without the outer shell);

[0033] Figure 5 for Figure 3 The main view;

[0034] Figure 6 for Figure 5 Middle AA section view;

[0035] Figure 7 for Figure 5 Middle BB section view;

[0036] Figure 8 for Figure 3 A top view of

[0037] Figure 9 for Figure 8 CC section view.

[0038] Figure: 1. Isolation cabinet; 2. Middle partition; 3. Vacuum cleaner; 4. External touch screen; 5. Horizontal stopper; 6. Vertical stopper; 7. Dust baffle; 8. Rotary motor; 9. Telescopic drive mechanism; 10. Vertical slide; 11. Horizontal slide; 12. Chuck; 13. Gripping jaws; 14. Horizontal slide; 15. Core sample; 17. Vertical slide; 19. Support frame; 20. Ejector ring; 201. Axial tension spring; 21. Vertical frame 22. Limiting frame; 23. Threaded shaft; 24. Lifting frame; 25. Rotary drive mechanism; 26. Active pulley; 27. Transmission belt; 28. Third pulley; 29. ​​Guide connecting rod; 30. First compression spring; 32. Triangular plate; 33. Dovetail block; 34. Second pulley; 35. Conical cylinder; 36. Second compression spring; 37. Support shaft; 38. Sanding roller; 39. Sliding block; 40. Limiting ring; 50. Power module; 60. Clamping module. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments 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 any creative efforts shall fall within the scope of protection of the present invention.

[0040] An embodiment of a micro core fine processing grinding device and a core preparation method of the present invention is as follows: Figures 1 to 9 As shown, the micro-core fine processing and grinding device includes a circumferentially closed isolation cabinet 1, which is provided with a middle partition 2 inside. The middle partition 2 divides the interior of the entire isolation cabinet 1 into two upper and lower chambers. The upper chamber is the grinding chamber, in which the core sample 15 to be polished is polished. The upper side of the middle partition 2 forms a grinding platform. The chamber below the middle partition 2 is the dust collection chamber, in which a vacuum cleaner 3 is provided. The vacuum cleaner 3 is connected to the grinding chamber through a dust collection pipe to absorb dust generated in the grinding chamber. An external touch screen 4 is provided on one side of the isolation cabinet 1. The external touch screen 4 is operated by the staff to control the operation of the micro-core fine processing and grinding device.

[0041] In the present invention, the micro-core fine machining and grinding device further includes a clamping module 60 and a power module 50 disposed within the grinding chamber of the isolation cabinet 1. In this embodiment, both the clamping module 60 and the power module 50 are movably mounted on a grinding platform. Specifically, the grinding platform is provided with a transverse slide rail 14 extending in a left-right direction and a longitudinal slide rail 17 extending in a front-back direction. The transverse slide rail 14 guides a transverse slide 11 that moves in a left-right direction, while the longitudinal slide rail 17 guides a longitudinal slide 10 that moves in a front-back direction. The clamping module 60 is arranged on the transverse slide 11, and the power module 50 is arranged on the longitudinal slide 10. The transverse slide 11 moves left and right to drive the clamping module 60 to move closer to or away from the power module 50. The longitudinal slide 10 moves forward and backward to drive the power module 50 to stagger or align with the clamping module 60 in the front-to-back direction. When the clamping module 60 and the power module 50 are staggered in the front-to-back direction, it is beneficial to make enough space for the clamping module 60 to install and remove the core sample 15. In the present invention, the left end of the transverse slide 14 is connected to a transverse limiter 5, and the front end of the longitudinal slide 17 is connected to a longitudinal limiter 6. The transverse limiter 5 and the longitudinal limiter 6 are used to drive the transverse slide 11 and the longitudinal slide 10 to move a set distance respectively. It should be noted that the transverse slide 14, the longitudinal slide 17, the transverse slide 11, the longitudinal slide 10, the transverse limiter 5, the longitudinal limiter 6 and the vacuum cleaner 3 are all existing known structures and will not be described in detail here.

[0042] In the present invention, the clamping module 60 includes a chuck 12 and a clamping jaw 13 movably mounted on the end surface of the chuck 12. The clamping jaw 13 is used to clamp one end of the core sample 15. The chuck 12 is rotatably mounted on the left end of the transverse slide 11. The right end of the transverse slide 11 is provided with a rotary motor 8. The rotary motor 8 is in transmission connection with the chuck 12 to drive the chuck 12 to rotate. It should be noted that the rotary motor 8, chuck 12, clamping jaw 13, and the connection and matching structure between the three are all existing structures and will not be described in detail here. The clamping module 60 also includes three sanding rollers 38 evenly spaced and arranged around the periphery of the clamping jaw 13. The three sanding rollers 38 are parallel to each other and their axes extend in the left-right direction. The axis of the sanding rollers 38 extends in the same direction as the axis of the core sample 15 clamped in the clamping jaw 13. The outer periphery of the three sanding rollers 38 is used to clamp the core sample 15 and grind the outer peripheral surface of the core sample 15.

[0043] In this embodiment, a limit ring 40 is fixed to the periphery of the jaws 13 on the end surface of the chuck 12. The limit ring 40 is provided with three radially extending slots at intervals along its circumference. The three slots correspond to the three sanding rollers 38, and a sliding block 39 is provided in each slot for guiding movement. The jaws 13 and the sliding blocks 39 each have three, and are alternately and evenly spaced along the circumference of the chuck 12. One end of each of the three sanding rollers 38 is rotatably mounted on the three sliding blocks 39. When the three sliding blocks 39 approach each other in the radial direction of the chuck 12, they drive the three sanding rollers 38 toward each other to clamp the outer periphery of the core sample 15. When the three sliding blocks 39 move away from each other in the radial direction of the chuck 12, they drive the three sanding rollers 38 away from each other to loosen the core sample 15. In this embodiment, a radial tension spring is provided in each slide groove, one end of the radial tension spring is fixedly connected to the sliding block 39, and the other end is fixedly connected to the limiting ring 40. In the initial state, each radial tension spring drives the sliding block 39 to move away from each other along the radial direction of the limiting ring 40, so that the three sanding rollers 38 move away from each other.

[0044] The power module 50 is used to be in transmission connection with the three sanding rollers 38, and drives the sanding rollers 38 to rotate to grind the outer periphery of the core sample 15. The transverse slide 11 drives the clamping module 60 to move left and right, so that the clamping module 60 and the power module 50 move closer to or farther away from each other, thereby achieving a clutch between the power module 50 and the three sanding rollers 38. When one end of the core sample 15 is clamped by the chuck 12, the power module 50 and the clamping module 60 move closer to each other, and the power module 50 is in transmission connection with the sanding rollers 38. When the core sample 15 needs to be removed, the power module 50 and the clamping module 60 separate from each other, and the power module 50 is disconnected from the sanding rollers 38.

[0045] In this embodiment, the power module 50 includes a housing, a support frame 19 disposed within the housing, a rotary drive mechanism 25, a driving pulley 26, and three transmission pulleys. A dust shield 7 is fixed to the exterior of the housing, and a dust suction port is provided on the dust shield 7. The vacuum cleaner 3 is connected to the dust suction port on the dust shield 7 via a dust suction duct. When grinding the core sample 15, the dust suction port faces one side of the core sample 15 to suction debris from the surface of the core sample 15. The three transmission pulleys are arranged in an equilateral triangle and correspond one-to-one with the three sanding rollers 38. In this embodiment, the rotary drive mechanism 25 is a motor, disposed on the support frame 19, and connected to the driving pulley 26. The driving pulley 26 is connected to all three transmission pulleys via a common transmission belt 27. When the power module 50 and the clamping module 60 are brought into proximity with each other, the end of each sanding roller 38 facing away from the chuck 12 is respectively engaged with the end of the corresponding drive pulley and is locked in rotation. When the power module 50 and the clamping module 60 are separated from each other, the end of each sanding roller 38 facing away from the chuck 12 is respectively disconnected from the corresponding drive pulley. In this embodiment, a square hole is defined at the end of each sanding roller 38 facing away from the chuck 12, and a square shaft is provided at the end of each drive pulley facing the sanding roller 38 to fit into the square hole. In an initial state, the spacing between the three drive pulleys is the same as the spacing between the three sanding rollers 38. Thus, when the clamping module 60 and the power module 50 are aligned front-to-back and brought into proximity with each other, the square shafts on the three drive pulleys can be engaged with the square holes on the three sanding rollers 38, thereby achieving a transmission connection between the power module 50 and the sanding rollers 38.

[0046] In this embodiment, in order to ensure that the spacing between the three drive pulleys matches the spacing between the three sanding rollers 38, that is, to enable the three drive pulleys to move toward and away from each other, the power module 50 further includes a tapered cylinder 35 movably mounted on the support frame 19 in the left-right direction, and a deformable bracket movably connected to the tapered cylinder 35. The deformable bracket includes three connecting shafts, each of which has an axis extending in the left-right direction and corresponding to each of the three sanding rollers 38. The three drive pulleys are rotatably mounted on one end of each connecting shaft facing the sanding roller 38. A guide link 29 is connected between each two adjacent connecting shafts. One end of the guide link 29 is fixedly connected to one of the two adjacent connecting shafts, and the other end is movably inserted into the other connecting shaft. The three guide links 29 form an equilateral triangle structure. Each guide link 29 is sleeved with a first compression spring 30. The first compression spring 30 presses between the two adjacent connecting shafts, causing the three connecting shafts to move away from each other in the initial state. The axis of the tapered cylinder 35 extends in the left-right direction, and one end of the tapered cylinder 35 is a flared end and the other end is a closed end. The flared end of the tapered cylinder 35 faces the chuck 12. A dovetail groove extending along the busbar of the tapered cylinder 35 is provided on the inner wall of the tapered cylinder 35. Three dovetail grooves are evenly spaced along the circumference of the tapered cylinder 35. A dovetail block 33 is fixed to the end of the three connecting shafts away from the transmission pulley. Each dovetail block 33 is slidably installed in the corresponding dovetail groove. When the tapered cylinder 35 moves in the left-right direction relative to the support frame 19, the dovetail block 33 moves along the extension direction of the dovetail groove, so that the three connecting shafts are close to or away from each other along the radial direction of the tapered cylinder 35.

[0047] Furthermore, the support frame 19 includes a vertical frame 21 and a support shaft 37 cantilevered from the vertical frame 21 in the horizontal direction. The conical cylinder 35 is movably mounted on the support shaft 37 in the horizontal direction. Three connecting shafts and three guide links 29 are respectively located on the periphery of the support shaft 37. The power module 50 also includes a telescopic drive mechanism 9, which is a telescopic cylinder having a fixed cylinder body and a telescopic shaft that can be extended and retracted in the horizontal direction. The fixed cylinder body of the telescopic cylinder is fixed to the outer wall of the housing of the power module 50. When the telescopic shaft is extended, it pushes the conical cylinder 35 toward the chuck 12, causing the three connecting shafts to move closer to each other along the radial direction of the conical cylinder 35. When the telescopic shaft is retracted, the conical cylinder 35 loses the pushing effect of the telescopic cylinder, and the first compression spring 30 mounted on the guide link 29 drives the three connecting shafts away from each other, causing the dovetail block 33 on each connecting shaft to slide along the dovetail groove.

[0048] Furthermore, in order to control the tightness of the transmission belt 27 so as to achieve the three transmission pulleys approaching and moving away from each other, in this embodiment, the support frame 19 includes a limit bracket and a lifting frame 24 movably arranged in the limit bracket along the up and down directions. The limit bracket and the lifting frame 24 are located below the transmission pulley. A lifting drive mechanism is provided below the lifting frame 24. The rotation drive mechanism 25 is arranged on the lifting frame 24. The active pulley 26 is rotatably installed on the lifting frame 24. The lifting frame 24 adjusts the tension of the transmission belt 27 as it moves up and down. When the transmission pulley separates from the sanding rollers 38, the lifting frame 24 rises to loosen the transmission belt 27, separating the transmission belt 27 from the respective transmission pulleys. When the three sanding rollers 38 approach each other and clamp the core sample 15, the lifting frame 24 descends to tighten the transmission belt 27 and tightly fit it against the respective transmission pulleys. The limiting bracket is provided with rotatable tensioning pulleys on opposite sides of the transmission belt 27. The two tensioning pulleys are respectively located above the driving pulley 26, and the distance between the two tensioning pulleys is less than the outer diameter of the driving pulley 26. In this embodiment, the lifting drive mechanism includes a threaded shaft 23 extending in the vertical direction. The threaded shaft 23 is threadedly engaged with the lifting frame 24. The lower end of the threaded shaft 23 is rotatably mounted on the bottom of the limiting frame 22. A lifting drive motor is provided at the bottom of the limiting frame 22, and the lower end of the threaded shaft 23 is connected to the lifting drive motor. A guide shaft extending in the up-down direction is provided on one side of the threaded shaft 23 at the bottom of the limiting frame 22 , and the guide shaft is guided and matched with the lifting frame 24 .

[0049] In this embodiment, a push ring 20 is provided on the upright frame 21 along a left-right guide. The telescopic drive mechanism 9 pushes the conical tube 35 via the push ring 20. One end of the push ring 20 engages with the closed end of the conical tube 35, while the other end engages with the telescopic shaft. An axial tension spring 201 is connected between the closed end of the conical tube 35 and the upright frame 21. One end of the axial tension spring 201 is connected to the closed end of the conical tube 35, while the other end is connected to the upright frame 21. When the telescopic shaft is shortened, the axial tension spring 201 drives the conical tube 35 away from the chuck 12, and the first compression spring 30 drives the three connecting shafts away from each other along the radial direction of the conical tube 35.

[0050] In this embodiment, the push ring 20 is composed of a plurality of guide rods and two circular rings arranged symmetrically on the left and right sides. The left and right circular rings are respectively located on the left and right sides of the vertical frame 21. The plurality of guide rods extend in the left and right directions and are evenly spaced along the circumference of the support shaft 37. The two ends of each guide rod are fixedly connected to the circular rings on the left and right sides respectively. Each guide rod is guided and passed through the vertical frame 21 along the left and right directions. One of the left and right circular rings is in push contact with the closing end of the conical cylinder 35, and the other is in push contact with the telescopic shaft of the telescopic drive mechanism 9.

[0051] In this embodiment, the deformable bracket also includes a triangular plate 32, the center of which is provided with a through hole, and the triangular plate 32 is installed on the support shaft 37 through the through hole. The triangular plate 32 is provided with three guide grooves extending radially along the through hole on the periphery of the through hole, and the guide grooves are arranged in a one-to-one correspondence with the connecting shafts, and each connecting shaft is respectively provided in the corresponding guide groove, and the side wall of the connecting shaft is provided with a card groove that cooperates with the side wall of the triangular plate 32 to prevent the triangular plate 32 from moving axially along the connecting shaft.

[0052] In this embodiment, two of the three transmission pulleys have the same outer diameter, namely the first pulley and the second pulley 34. The other has a larger outer diameter than the first and second pulleys 34, namely the third pulley 28. The first and second pulleys 34 are respectively located below the third pulley 28. When the driving pulley 26 drives the three transmission pulleys to rotate via the transmission belt 27, the rotation speeds of the first and second pulleys 34 are greater than the rotation speed of the third pulley 28. This causes the rotation speed of the sanding roller 38 connected to the third pulley 28 to be less than the rotation speed of the sanding roller 38 connected to the first and second pulleys 34. In the present invention, after the three sanding rollers 38 approach each other and clamp the outer circumference of the core sample 15, the clamping jaws 13 release the core sample 15, releasing the clamping action on the core sample 15, allowing the core sample 15 to rotate with the rotation of the three sanding rollers 38. Specifically, among the three sanding rollers 38, the rotation speed of the two sanding rollers 38 connected to the first pulley and the second pulley 34 is relatively high, so that the friction between these two sanding rollers 38 and the core sample 15 is relatively large. In this way, the two sanding rollers 38 connected to the first pulley and the second pulley 34 respectively can drive the core sample 15 to rotate around its own axis, while the sanding roller 38 connected to the third pulley 28 has a lower rotation speed and will generate relative rotation with the core sample 15, thereby grinding the core sample 15.

[0053] In this embodiment, the outer circumferences of the three sanding rollers 38 all have a grinding layer, and the mesh sizes of the grinding layers of the three sanding rollers 38 are different. That is, the three sanding rollers 38 have different grinding accuracies for the core sample 15. Specifically, a larger mesh size of the grinding layer results in a more detailed grinding of the outer circumference of the core sample 15 and a higher grinding accuracy. Conversely, a smaller mesh size results in a coarser grinding and a lower grinding accuracy. In this embodiment, the mesh sizes of the grinding layers of the three sanding rollers 38 are 800 mesh, 1200 mesh, and 2000 mesh, respectively. During use, when the transverse slide 11 drives the clamping module 60 to separate from the power module 50, the chuck 12 is driven to rotate by the rotating motor 8. The rotation of the chuck 12 can switch the circumferential position of the three sanding rollers 38, so that the three sanding rollers 38 are respectively connected to different transmission pulleys. Since the grinding layer mesh numbers of the outer periphery of the three sanding rollers 38 are different, the different sanding rollers 38 can perform different precision grinding on the outer periphery of the core sample 15 after being connected to the third pulley 28. In this way, by switching different sanding rollers 38, the core sample 15 can be polished multiple times and with different precisions.

[0054] Since the jaws 13 release the core sample 15 during grinding, to prevent axial movement of the core sample 15, in this embodiment, a support shaft 37 is movably mounted on the stand 21 in the left-right direction. A second compression spring 36 is sleeved on the support shaft 37. The second compression spring 36 is located within the conical barrel 35. One end of the second compression spring 36 contacts the inner wall of the closed end of the conical barrel 35. The other end of the second compression spring 36 contacts the shoulder provided on the sidewall of the support shaft 37. When the conical barrel 35 moves toward the chuck 12, the second compression spring 36 drives the support shaft 37 toward the chuck 12, causing the end of the support shaft 37 facing the chuck 12 to abut against the end of the core sample 15. This abutment between the support shaft 37 and the end of the core sample 15 prevents the core sample 15 from moving toward the conical barrel 35.

[0055] The present invention uses the core preparation method of the micro core fine processing grinding device, the micro core fine processing grinding device is as follows Figures 1 to 9 As shown, the core preparation method includes inserting a cylindrical core sample 15 between three sanding rollers 38 of a clamping module 60. The clamping jaws 13 clamp one end of the core sample 15 to secure the core sample 15 to the chuck 12. The clamping module and the power module 50 are brought into close proximity and connected in a transmission manner. The three sanding rollers 38 approach each other and clamp the outer periphery of the core sample 15. The power module 50 drives the sanding rollers 38 to rotate to grind the outer periphery of the core module. The specific steps are as follows:

[0056] a. Prepare core sample 15. Select an initial core sample that meets the length requirements. Then, perform a CT scan on the initial core sample to identify the target area. Use a wire cutting tool to cut the portion of the initial core sample containing the target area into a cylindrical core sample 15. The core sample 15 has a diameter of approximately 1 cm and flat end surfaces at both ends.

[0057] b. Grinding the core sample 15 for the first time. In the initial state, the clamping module 60 and the power module 50 are separated and staggered in the front-to-back direction, as shown in FIG. Figure 2 The core sample 15 is inserted between the three sanding rollers 38, and the jaws 13 grip one end of the core sample 15. The rotary motor 8 drives the chuck 12 to rotate, positioning the sanding roller 38 with an 800-grit grinding layer at the top, corresponding to the position of the third pulley 28. The external touchscreen 4 is used to adjust the position of the longitudinal slide 10, aligning the clamping module 60 and the power module 50. The transverse slide 11 is then adjusted to position the clamping module 60 carrying the core sample 15 close to the power module 50, connecting the sanding rollers 38 to the drive pulleys. The telescopic shaft of the telescopic drive mechanism 9 is then extended, pushing the conical cylinder 35 toward the chuck 12 until the outer circumferences of the three sanding rollers 38 are aligned with the outer circumferences of the core sample 15. The telescopic drive mechanism 9 then stops extending, and the lifting drive mechanism lowers the lifting frame 24, tightening the drive belt 27 and connecting it to the three drive pulleys. The clamping jaws 13 are then controlled to release the core sample 15, the vacuum cleaner 3 is activated, and the rotary drive mechanism 25 is activated, with the rotational speed of the rotary drive mechanism 25 set to 3000 rpm. The two lower sanding rollers 38 of the three sanding rollers 38 rotate at the same speed, driving the core sample 15 to rotate at the same speed. The upper sanding roller 38 rotates at a lower speed than the two lower sanding rollers 38, causing relative sliding between the sanding roller 38 and the core sample 15, thereby grinding the outer circumference of the core sample 15. During the grinding process, the telescopic rod of the telescopic drive mechanism 9 extends at a set speed, causing the conical cylinder 35 to move toward the chuck 12 at a set speed, causing the three connecting shafts to approach the core sample 15 radially at a feed rate of 0.05 mm / min. In other words, the feed rate of the sanding rollers 38 is 0.05 mm / min, and the grinding feed amount for the entire first grinding is 2 mm.

[0058] c. Grind the core sample 15 for the second time. After the first grinding is completed, the rotary drive mechanism 25 is stopped, and the lifting frame 24 is raised to release the transmission belt 27 , and the clamping jaw 13 is clamped to one end of the core sample 15 . Then the telescopic drive mechanism 9 contracts, and after the conical cylinder 35 loses its pushing effect, under the action of the first compression spring 30 and the circumferential tension spring, the conical cylinder 35 moves in the direction away from the chuck 12, and the three connecting shafts move together with the conical cylinder 35 in the direction away from the chuck 12, and at the same time move away from each other along the radial direction of the core sample 15, and the transverse slide 11 drives the clamping component to move in the direction away from the power module 50, and then the rotating motor 8 drives the chuck 12 to rotate the set angle, switches the sanding roller 38 with a grinding layer of 1200 mesh to the upper position, and then re-docking the clamping module 60 and the power module 50 and transmission connection. In this step, the rotation speed of the rotary drive motor is set to 2000rpm, the grinding feed amount of the sanding roller 38 is 2mm, and the feed speed is 0.02mm / min.

[0059] d. Grind the core sample 15 for the third time. According to step (3), the sanding roller 38 with a grinding layer of 2000 mesh is switched to the upper position, and then the clamping module 60 and the power module 50 are re-connected and transmission-connected. In this step, the speed of the rotary drive motor is set to 2000 rpm, the grinding feed of the sanding roller 38 is 1 mm, and the feed rate is 0.01 mm / min.

[0060] e. Following the above operation process, the core sample 15 can be polished for the fourth time by replacing the sanding roller 38 with a larger mesh size, or more polishing and fine polishing can be performed to finally prepare a slender columnar core with a diameter of 1.89 mm and a length exceeding 3 cm.

[0061] The core sample 15 prepared by the core preparation method of the present invention has a scanning voxel accuracy of 1.743 μm in a micron CT system. During the core preparation process, manual operation is required only in the steps of adjusting the grinding parameters and replacing the grinding head. No human supervision is required in the rest of the process.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A micro core fine machining grinding device, comprising a grinding platform and a clamping module (60) arranged on the grinding platform, wherein the clamping module (60) comprises a chuck (12) and a clamping jaw (13) movably arranged on the end face of the chuck (12), wherein the clamping jaw (13) is used to clamp one end of a core sample (15), and is characterized in that: The clamping module (60) further includes three sanding rollers (38) evenly spaced around the periphery of the clamping jaws (13). The three sanding rollers (38) are parallel to each other and their axes extend in the left-right direction. The axis extension direction of the sanding rollers (38) is the same as the axis extension direction of the core sample (15) clamped on the clamping jaws (13). The periphery of the three sanding rollers (38) is used to clamp the core sample (15) and grind the outer peripheral surface of the core sample (15). The chuck (12) is provided with three sliding blocks (39) movable along the radial direction of the chuck (12) on the periphery of the clamping jaws (13). The three sliding blocks (39) are evenly spaced around the circumference of the chuck (12). One end of the three sanding rollers (38) is rotatably mounted on the three sliding blocks (39). The three sliding blocks (39) drive the three sanding rollers (38) when they approach each other in the radial direction of the chuck (12). The grinding platform is provided with a power module (50), which is used to be connected to the three sanding rollers (38) for transmission, and drives the sanding rollers (38) to rotate to grind the outer periphery of the core sample (15). At least one of the power module (50) and the clamping module (60) can move in the left and right directions to achieve clutch between the power module (50) and the three sanding rollers (38). When one end of the core sample (15) is clamped by the chuck (12), the power module (50) and the clamping module (60) are close to each other, and the power module (50) is connected to the sanding rollers (38). When the core sample (15) needs to be removed, the power module (50) and the clamping module (60) are separated from each other, and the power module (50) is disconnected from the sanding rollers (38).

2. The micro core fine machining grinding device according to claim 1, characterized in that: The power module (50) comprises a support frame (19), a rotary drive mechanism (25), a driving pulley (26) and three transmission pulleys. The rotary drive mechanism (25) is arranged on the support frame (19). The three transmission pulleys are arranged in an equilateral triangle and are respectively arranged in a one-to-one correspondence with the three sanding rollers (38). The rotary drive mechanism (25) is connected to the driving pulley (26). The driving pulley (26) is simultaneously connected to the three transmission pulleys through the same transmission belt (27). When the power module (50) and the clamping module (60) approach each other, the end of each sanding roller (38) away from the chuck (12) is respectively inserted and matched with the end of the corresponding transmission pulley and is rotationally fixed. When the power module (50) and the clamping module (60) are separated from each other, the end of each sanding roller (38) away from the chuck (12) is respectively disconnected from the corresponding transmission pulley.

3. The micro core fine machining grinding device according to claim 2, characterized in that: Two of the three transmission pulleys have the same outer diameter, namely the first pulley and the second pulley (34), and the other one has an outer diameter greater than the first pulley and the second pulley (34), namely the third pulley (28). The first pulley and the second pulley (34) are respectively located below the third pulley (28). When the active pulley (26) drives the three transmission pulleys to rotate through the transmission belt (27), the rotation speeds of the first pulley and the second pulley (34) are greater than the rotation speed of the third pulley (28), so that the rotation speed of the sanding roller (38) connected to the third pulley (28) is less than the rotation speed of the sanding roller (38) connected to the first pulley and the second pulley (34). When the three sanding rollers (38) approach each other and clamp the periphery of the core sample (15), The clamping jaws (13) release the grip on the core sample (15), and the two sanding rollers (38) respectively connected to the first pulley and the second pulley (34) are used to drive the core sample (15) to rotate. The sanding roller (38) connected to the third pulley (28) rotates relative to the core sample (15) to grind the core sample (15); the outer peripheral surfaces of the three sanding rollers (38) are all provided with a grinding layer, and the mesh counts of the grinding layers of the three sanding rollers (38) are all different. The three sanding rollers (38) have different grinding precisions for the core sample (15). When the chuck (12) is rotated, the circumferential positions of the three sanding rollers (38) can be switched, so that the three sanding rollers (38) are respectively connected to different transmission pulleys.

4. The micro core fine machining grinding device according to claim 3, characterized in that: The invention comprises a circumferentially closed isolation cabinet (1), wherein a middle partition (2) is provided inside the isolation cabinet (1), wherein the middle partition (2) divides the internal space of the entire isolation cabinet (1) into two upper and lower chambers, wherein the upper chamber is a grinding chamber, and the upper side of the middle partition (2) forms the grinding platform, wherein the clamping module (60) and the power module (50) are arranged on the middle partition (2), and the core sample (15) to be ground is placed in the grinding chamber. The grinding is performed, the chamber located below the middle partition (2) is a dust suction chamber, a dust collector (3) is provided in the dust suction chamber, a dust baffle (7) is provided on one side of the power module, a dust suction port is provided on the dust baffle (7), the dust collector (3) is connected to the dust suction port on the dust baffle (7) through a dust suction pipe, and when the core sample (15) is ground, the dust suction port faces one side of the core sample (15) to suck debris on the surface of the core sample (15).

5. The micro core fine machining and grinding device according to claim 4, characterized in that: The power module (50) includes a deformable bracket, and the deformable bracket includes three connecting shafts. The axes of the three connecting shafts extend in the left-right direction and are arranged in one-to-one correspondence with the three sanding rollers (38). Three transmission pulleys are rotatably installed on one end of each connecting shaft facing the sanding roller (38). A guide link (29) is connected between each two adjacent connecting shafts. One end of the guide link (29) is fixedly connected to one of the two adjacent connecting shafts, and the other end is movably inserted into the other connecting shaft. The three guide links (29) form an equilateral triangle structure. Each guide link (29) is sleeved with a first compression spring (30). The first compression spring (30) presses between the two adjacent connecting shafts to make the three connecting shafts move away from each other in the initial state.

6. The micro core fine machining and grinding device according to claim 5, characterized in that: The power module (50) also includes a conical cylinder (35) movably arranged on the support frame (19) in the left and right directions, the axis of the conical cylinder (35) extending in the left and right directions, and one end of the conical cylinder (35) is a flared end and the other end is a closed end, the flared end of the conical cylinder (35) faces the chuck (12), and a dovetail groove extending along the busbar of the conical cylinder (35) is opened on the inner wall of the conical cylinder (35), and three dovetail grooves are evenly spaced along the circumference of the conical cylinder (35), and a dovetail block (33) is fixed at one end of the three connecting shafts away from the transmission pulley, and each dovetail block (33) is slidably installed in the corresponding dovetail groove. When the conical cylinder (35) moves in the left and right directions relative to the support frame (19), the dovetail block (33) moves along the extension direction of the dovetail groove, so that the three connecting shafts are close to or away from each other along the radial direction of the conical cylinder (35).

7. The micro core fine machining grinding device according to claim 6, characterized in that: The support frame (19) includes a stand (21) and a support shaft (37) cantilevered on the stand (21) in the left-right direction. The conical cylinder (35) is movably sleeved on the support shaft (37) in the left-right direction. Three connecting shafts and three guide connecting rods (29) are respectively located on the periphery of the support shaft (37). The power module (50) also includes a telescopic drive mechanism (9). The telescopic drive mechanism (9) has a telescopic shaft extending in the left-right direction. When the telescopic shaft is extended, it pushes the conical cylinder (35) to move toward the chuck (12), so that the three connecting shafts are close to each other along the radial direction of the conical cylinder (35).

8. The micro core fine machining and grinding device according to claim 7, characterized in that: A push ring (20) is provided on the vertical frame (21) along the left and right directions. One end of the push ring (20) is in push contact with the closing end of the conical cylinder (35), and the other end is in push contact with the telescopic shaft. An axial tension spring (201) is connected between the closing end of the conical cylinder (35) and the vertical frame (21). One end of the axial tension spring (201) is connected to the closing end of the conical cylinder (35), and the other end is connected to the vertical frame (21). When the telescopic shaft is shortened, the axial tension spring (201) drives the conical cylinder (35) to move in a direction away from the chuck (12), and the first compression spring (30) drives the three connecting shafts to move away from each other along the radial direction of the conical cylinder (35).

9. The micro core fine machining grinding device according to claim 8, characterized in that: The push ring (20) is composed of a plurality of guide rods and two circular rings arranged symmetrically on the left and right sides. The left and right circular rings are respectively located on the left and right sides of the vertical frame (21). The plurality of guide rods extend in the left and right directions and are evenly spaced along the circumference of the support shaft (37). The two ends of each guide rod are fixedly connected to the circular rings on the left and right sides respectively. Each guide rod is guided and passed through the vertical frame (21) in the left and right directions. One of the left and right circular rings is in push-pushing contact with the closing end of the conical cylinder (35), and the other is in push-pushing contact with the telescopic shaft of the telescopic drive mechanism (9).

10. The micro core fine machining and grinding device according to claim 7, characterized in that: The deformable bracket also includes a triangular plate (32), a through hole is provided at the center of the triangular plate (32), and the triangular plate (32) is installed on the support shaft (37) through the through hole. Three guide grooves extending along the radial direction of the through hole are provided on the triangular plate (32) at the periphery of the through hole. The guide grooves are arranged in a one-to-one correspondence with the connecting shafts, and each connecting shaft is respectively inserted into the corresponding guide groove. The side wall of the connecting shaft is provided with a slot that cooperates with the side wall of the triangular plate (32) to prevent the triangular plate (32) from moving axially along the connecting shaft.

11. The micro core fine machining grinding device according to claim 7, characterized in that: The support shaft (37) is movably arranged on the stand (21) in the left and right directions. A second compression spring (36) is sleeved on the support shaft (37). The second compression spring (36) is located inside the conical cylinder (35). One end of the second compression spring (36) contacts the inner wall of the closing end of the conical cylinder (35). A shaft shoulder is provided on the side wall of the support shaft (37). The other end of the second compression spring (36) contacts the shaft shoulder. When the conical cylinder (35) moves toward the chuck (12), the conical cylinder (35) drives the support shaft (37) to move toward the chuck (12) through the second compression spring (36), so that one end of the support shaft (37) toward the chuck (12) is in contact with the end of the core sample (15) to prevent the core sample (15) from moving toward the conical cylinder (35).

12. The micro core fine machining grinding device according to claim 2, characterized in that: The support frame (19) includes a limit bracket and a lifting frame (24) movably arranged in the limit bracket along the up and down directions. The limit bracket and the lifting frame (24) are located below the transmission pulley. A lifting drive mechanism is provided below the lifting frame (24). The rotary drive mechanism (25) is arranged on the lifting frame (24). The active pulley (26) is rotatably mounted on the lifting frame (24). The lifting frame (24) adjusts the tightness of the transmission belt (27) when it moves up and down. When the transmission pulley is separated from the sanding roller (38), the driving belt (26) is rotated and mounted on the lifting frame (24). The lifting frame (24) is raised to loosen the transmission belt (27), and the transmission belt (27) is separated from each transmission pulley. When the three sanding rollers (38) approach each other and clamp the core sample (15), the lifting frame (24) is lowered to tighten the transmission belt (27) and fit closely with each transmission pulley. Tensioning wheels are respectively provided on the limiting bracket on opposite sides of the transmission belt (27). The two tensioning wheels are respectively located above the driving pulley (26), and the distance between the two tensioning wheels is smaller than the outer diameter of the driving pulley (26).

13. The micro core fine machining and grinding device according to claim 5, characterized in that: A limiting ring (40) is fixed on the periphery of the clamping jaw (13) on the chuck (12), and three sliding grooves extending along its own radial direction are provided at circumferential intervals on the limiting ring (40). The sliding blocks (39) are respectively guided and installed in the corresponding sliding grooves, and radial tension springs are respectively provided in each sliding groove. One end of the radial tension spring is fixedly connected to the sliding block (39), and the other end is fixedly connected to the limiting ring (40). When each sanding roller (38) is separated from the transmission pulley, each radial tension spring drives the sliding block (39) to move away from each other along the radial direction of the limiting ring (40), so that the three sanding rollers (38) are moved away from each other.

14. The micro core fine machining and grinding device according to claim 2, characterized in that: The polishing platform is provided with a transverse slide rail (14) extending in the left-right direction and a longitudinal slide rail (17) extending in the front-back direction. The transverse slide rail (14) is provided with a transverse slide seat (11) moving in the left-right direction, and the longitudinal slide rail (17) is provided with a longitudinal slide seat (10) moving in the front-back direction. The clamping module (60) is arranged on the transverse slide seat (11), and the power module (50) is arranged on the longitudinal slide seat (10). The transverse slide seat (11) moves left and right to drive the clamping module (60) to approach or move away from the power module (50), and the longitudinal slide seat (10) moves forward and backward to drive the power module (50) to stagger or align with the clamping module (60) in the front-back direction.

15. A core preparation method using the micro-core fine processing grinding device according to any one of claims 1 to 14, characterized in that: The method comprises the following steps: a. preparing a core sample (15); selecting an initial core sample that meets the length requirement, then performing CT scanning on the initial core sample to select a target area, and using a wire cutting tool to cut the portion of the initial core sample containing the target area into a columnar core sample (15), wherein both ends of the core sample (15) are flat end surfaces; b. Grinding the core sample (15) for the first time; The columnar core sample (15) is inserted between the three sanding rollers (38) of the clamping module (60), and the clamping claw (13) clamps one end of the core sample (15) to fix the core sample (15) on the chuck (12). The clamping module and the power module (50) are close to each other and connected in transmission. The three sanding rollers (38) are close to each other and clamp the outer periphery of the core sample (15). The power module (50) drives the sanding rollers (38) to rotate to grind the outer periphery of the core module. The core sample is ground using a sanding roller with a grinding layer of 800 mesh. The core sample (15) is ground, the rotation speed of the rotary drive mechanism (25) is set to 3000 rpm, the telescopic rod of the telescopic drive mechanism (9) is extended at the set speed, the conical cylinder (35) is moved toward the chuck (12) at the set speed, and the three sanding rollers (38) are moved close to the core sample (15) along the radial direction of the core sample (15) at a feed speed of 0.05 mm / min, that is, the feed speed of the sanding rollers (38) is 0.05 mm / min, and the grinding feed amount of the entire first grinding is 2 mm; c. Grinding the core sample (15) for the second time; grinding the core sample (15) using a sanding roller with a grinding layer of 1200 mesh, setting the rotation speed of the rotary drive motor to 2000 rpm, the grinding feed of the sanding roller (38) to 2 mm, and the feed speed to 0.02 mm / min; d. Grind the core sample (15) for the third time; use a sanding roller with a grinding layer of 2000 mesh to grind the core sample (15), set the speed of the rotary drive motor to 2000 rpm, the grinding feed amount of the sanding roller 38 to 1 mm, and the feed speed to 0.01 mm / min.

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