Hollow cylinder sample preparation device and method

Abstract

The invention discloses a hollow cylinder sample preparation device and method.The device comprises an outer cylinder mold, an inner cylinder mold, a sample loading structure and a compaction structure, the outer cylinder mold is arranged on the periphery of the inner cylinder mold in a sleeving mode, and a hollow cylinder sample preparation space is formed between the outer cylinder mold and the inner cylinder mold; the outer cylinder mold and the inner cylinder mold are each in a cylinder shape defined by a plurality of arc-shaped plates. The sample loading structure is detachably mounted above the sample preparation space and is used for uniformly falling materials into the sample preparation space, the compaction structure is detachably mounted above the sample preparation space, and a compaction end of the compaction structure can be lifted and is used for compacting the materials in the sample preparation space; according to the device, a standardized hollow cylindrical sample preparation space is formed through the outer barrel mold and the inner barrel mold, and controllable operation of sample loading and compaction is realized by combining a detachable sample loading structure and a compaction structure, so that the uniformity of a sample and the sample preparation efficiency are greatly improved, and personal errors are reduced.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, and in particular to a hollow cylindrical sample preparation device and method. Background Technology

[0002] The hollow cylindrical torsion shear apparatus can apply rotational displacement and torque to soil, control the magnitude and direction of the three principal stresses, and realize more complex and realistic stress paths, including rotation of the principal stress axes. It is currently the most advanced geotechnical testing equipment for studying the mechanical properties of foundation soil and catastrophic assessment in engineering. However, the current sample preparation process relies entirely on manual labor, which is time-consuming, labor-intensive, and delays the test progress. It also makes it difficult to guarantee the sample preparation effect, and the repeatability is often poor due to human operational factors, resulting in certain errors. A semi-automatic sample preparation device for remolded sand hollow cylindrical specimens (patent number CN212110828U) addresses this issue, noting that the uniformity of hollow cylindrical specimens varies. Summary of the Invention

[0003] The purpose of this invention is to provide a hollow cylindrical sample preparation device and method, which solves the problems of poor repeatability, operational errors and uneven sample preparation in existing hollow cylindrical sample preparation equipment.

[0004] This invention is implemented as follows: It provides a hollow cylindrical sample preparation device, comprising an outer cylinder mold, an inner cylinder mold, a sample loading structure, and a compaction structure. The outer cylinder mold is sleeved around the outer periphery of the inner cylinder mold, forming a hollow cylindrical sample preparation space between them. Both the outer cylinder mold and the inner cylinder mold are formed into a cylindrical shape by multiple arc-shaped plates. The sample loading structure is detachably installed above the sample preparation space to uniformly drop materials into the space. The compaction structure is detachably installed above the sample preparation space, and its compaction end is movable to compact the materials within the space.

[0005] The device forms a standardized hollow cylindrical sample preparation space through an outer cylinder and an inner cylinder mold. Combined with a detachable sample loading and compaction structure, it enables controllable operation of sample loading and compaction, greatly improving the uniformity of the sample and the efficiency of sample preparation, and reducing human error.

[0006] A further technical solution of the present invention is: the bottom of the outer cylinder mold is provided with a base, and the base is provided with two limiting grooves, one inside and one outside, which limit the bottom of the outer cylinder mold and the other inside the inner cylinder mold respectively.

[0007] The limiting groove on the base ensures the precise positioning and stability of the outer and inner cylinder molds, preventing the molds from shifting during the sample preparation process, thereby ensuring the geometric consistency and sample quality of the hollow cylindrical sample.

[0008] A further technical solution of the present invention is: an outer cylinder hoop is fitted around the outer circumference of the outer cylinder mold, and a support cylinder for supporting the inner cylinder mold is provided inside the inner cylinder mold. A column is provided on the support cylinder, and the column passes through the support cylinder and is connected to the base.

[0009] The outer cylinder hoop restrains the outer cylinder mold to prevent expansion and deformation, while the supporting cylinder fixes the inner cylinder mold through the column, enhancing the rigidity and stability of the overall structure, ensuring that the mold does not deform during sample preparation, and improving the accuracy of the sample.

[0010] A further technical solution of the present invention is: the inner diameter of the outer cylinder hoop is equal to the outer diameter of the outer cylinder mold, the outer diameter of the supporting cylinder is equal to the inner diameter of the inner cylinder mold, and the supporting cylinder enters and exits the inner cylinder mold through the column.

[0011] The dimensional matching between the outer cylinder hoop and the supporting cylinder ensures tight constraint and reliable support of the mold, facilitates assembly and disassembly, and improves operational convenience and sample preparation repeatability.

[0012] A further technical solution of the present invention is: a fixed base is provided below the base, and a cylinder is provided on the fixed base. The sample loading structure and the compaction structure are detachably installed on the cylinder by fixing bolts.

[0013] The fixed base and cylinder provide a stable support platform. The material feeding and compaction structure is adjustable and fixed by fixing bolts, allowing for flexible height adjustment, thereby controlling the sample drop distance and compaction position and optimizing sample preparation parameters.

[0014] A further technical solution of the present invention is: the sample loading structure includes a cylindrical tube and a positive funnel, a cylindrical channel and an inverted funnel arranged sequentially from top to bottom inside the cylindrical tube. The inverted funnel is provided with a conical baffle, which is fixed inside the cylindrical tube by a thin rod.

[0015] The dumbbell structure formed by the positive funnel, cylindrical channel and negative funnel, combined with the conical baffle, ensures that the material is evenly distributed during sample loading, avoiding the problem of uneven filling by manual pouring, and improving the uniformity of sample loading and the consistency of the sample.

[0016] A further technical solution of the present invention is: an outwardly extending inclined discharge channel is formed between the conical baffle and the anti-funnel, and the bottom of the cylindrical tube is a cylindrical discharge channel communicating with the inclined discharge channel.

[0017] The design of the inclined discharge channel and the cylindrical discharge channel further optimizes the material flow path, ensuring that the material evenly covers the sample preparation space, reducing local accumulation or gaps, and improving the sample loading quality.

[0018] A further technical solution of the present invention is: the compaction structure includes a hollow compaction disc, a two-hole disc, and a four-hole disc arranged sequentially from bottom to top. A cylinder is provided on the hollow compaction disc, and the cylinder passes through the four-hole disc and connects with the two-hole disc. The four-hole disc is fixed in position, while the two-hole disc is movable. A force transmission bolt is provided between the two-hole disc and the four-hole disc. By rotating the force transmission bolt, the hollow compaction disc can be driven to rise and fall.

[0019] This compaction structure transmits force through force-transmitting bolts, and the hollow compaction disc ensures uniform pressure distribution, achieving efficient and uniform compaction. This avoids the problem of uneven pressure in traditional compaction and improves the density and uniformity of the sample.

[0020] A further technical solution of the present invention is that the force transmission bolt is threadedly connected to the two-hole disc and the four-hole disc.

[0021] The threaded connection ensures stable transmission and precise control of the force-transmitting bolts, allowing for gradual application of pressure. The compaction process is controllable and repeatable, further guaranteeing the uniformity of compaction and the quality of the sample.

[0022] The present invention also provides a method for preparing a hollow cylinder sample, the method being based on the aforementioned apparatus, and the method comprising the following steps:

[0023] S1. Install the sample loading structure above the sample preparation space, pour the material into the sample loading structure, and after the material is uniformly processed by the sample loading structure, it falls into the sample preparation space to complete the sample loading.

[0024] S2. Remove the sample loading structure and install the compaction structure above the sample preparation space after loading.

[0025] S3. The compaction end of the compaction structure moves downward to compact the material in the sample preparation space, completing one compaction, and then the compaction structure is removed.

[0026] S4. Repeat steps S1-S3 until the sample preparation is completed. Disassemble the outer cylinder mold and the inner cylinder mold to obtain a hollow cylinder.

[0027] This method, through layered sample loading and compaction, combined with the uniform feeding and controllable compaction of the device, ensures high uniformity and density of hollow cylindrical samples, significantly improving sample preparation efficiency and repeatability, and reducing human error.

[0028] The beneficial effects of this invention are: This invention makes the sample preparation process of hollow cylinders more controllable, greatly improves the uniformity of sample loading and compaction, ensures sample quality, saves experimental sample preparation time, greatly reduces sample preparation time and human error, and improves sample preparation efficiency.

[0029] In this invention, the inner cylinder four-lobed mold is inserted into the inner circular groove of the base, the supporting cylinder is used to support the inner cylinder mold, and the outer cylinder hoop is fitted on the assembled three-lobed mold to constrain the outer cylinder, forming a standard hollow cylindrical mold. Furthermore, it will not deform during the sample preparation process, thus ensuring the effectiveness of producing hollow cylindrical samples.

[0030] In this invention, the fixing bolt hole of the sample loading structure passes through the cylinder. After moving to the required height, the bolt is tightened to fix it on the cylinder. When using the aerial sand rain method for sample loading, the relative density can be controlled by adjusting the drop distance.

[0031] The cylindrical channel in this invention can collect the incoming soil particles and distribute them evenly under the action of the conical baffle, which can improve the uniformity of the soil sample poured in during sample preparation and avoid the problem of some places having more soil and some places having less soil when manually pouring soil directly.

[0032] The structure of the two-hole disc, the force-transmitting bolt, and the four-hole disc in this invention provides a new compaction method. Because the bolt exerts a very large pressure, and the hollow disc makes the force distribution more uniform, the uniformity of compaction is improved. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the installation and loading structure of a hollow cylindrical sample preparation device according to the present invention;

[0034] Figure 2 This is a schematic diagram of the installation and compaction structure of a hollow cylindrical sample preparation device according to the present invention;

[0035] Figure 3 This is a cross-sectional view of a hollow cylindrical mold.

[0036] Figure 4 This is a cross-sectional structural diagram of the sample assembly structure;

[0037] Figure 5 This is a cross-sectional structural schematic diagram of the compaction device;

[0038] Figure 6 These are top views of a two-hole disk and a four-hole disk.

[0039] Reference numerals: 1-Fixed base, 2-Cylinder, 3-Fixing bolt, 4-Base, 5-Outer cylinder mold, 6-Inner cylinder mold, 7-Supporting cylinder, 8-Outer cylinder hoop, 9-Cylinder tube, 10-Positive funnel, 11-Cylindrical channel, 12-Inverted funnel, 13-Conical baffle, 14-Thin rod, 15-Cylindrical discharge channel, 16-Hollow compaction disc, 17-Round rod, 18-Two-hole disc, 19-Four-hole disc, 20-Force transmission bolt. Detailed Implementation

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0041] Example 1:

[0042] like Figure 1-6 The hollow cylindrical sample preparation device shown includes an outer cylinder mold 5, an inner cylinder mold 6, a sample loading structure, and a compaction structure. The outer cylinder mold 5 is sleeved around the outer periphery of the inner cylinder mold 6, forming a hollow cylindrical sample preparation space between the outer cylinder mold 5 and the inner cylinder mold 6. Both the outer cylinder mold 5 and the inner cylinder mold 6 are formed into a cylindrical shape by multiple arc-shaped plates. The sample loading structure is detachably installed above the sample preparation space to uniformly drop materials into the sample preparation space. The compaction structure is detachably installed above the sample preparation space, and the compaction end of the compaction structure can be raised and lowered to compact the materials in the sample preparation space.

[0043] The device forms a standardized hollow cylindrical sample preparation space through an outer cylinder and an inner cylinder mold. Combined with a detachable sample loading and compaction structure, it enables controllable operation of sample loading and compaction, greatly improving the uniformity of the sample and the efficiency of sample preparation, and reducing human error.

[0044] In this embodiment, the outer cylinder mold 5 is formed into a cylindrical shape by three arc-shaped plates. The bottom of the outer cylinder mold 5 is limited by a limiting groove and the outer periphery is limited by an outer cylinder hoop 8 to maintain the stability of the cylindrical structure of the outer cylinder mold 5.

[0045] In this embodiment, the inner cylinder mold 6 is formed by four arc-shaped plates. The bottom of the inner cylinder mold 6 is limited by the limiting groove of the inner ring of the base 4. In order to ensure the integrity and stability of the inner cylinder mold 6 during the compaction process, a support cylinder 7 is provided in the inner cylinder mold 6 for support. The support cylinder 7 can be removed and placed through the column, which is convenient for disassembly. This ensures the sampling operation after the sample preparation is complete.

[0046] In this embodiment, the bottom of the outer cylinder mold 5 is provided with a base 4, and the base 4 is provided with two limiting grooves, one inside and one outside, which limit the bottom of the outer cylinder mold 5 and the other inside the inner cylinder mold 6.

[0047] The limiting groove on the base ensures the precise positioning and stability of the outer and inner cylinder molds, preventing the molds from shifting during the sample preparation process, thereby ensuring the geometric consistency and sample quality of the hollow cylindrical sample.

[0048] In this embodiment, the outer cylinder mold 5 is fitted with an outer cylinder hoop 8, and the inner cylinder mold 6 is provided with a support cylinder 7 for supporting the inner cylinder mold 6. The support cylinder 7 is provided with a column, and the column passes through the support cylinder 7 and is connected to the base 4.

[0049] The outer cylinder hoop restrains the outer cylinder mold to prevent expansion and deformation, while the supporting cylinder fixes the inner cylinder mold through the column, enhancing the rigidity and stability of the overall structure, ensuring that the mold does not deform during sample preparation, and improving the accuracy of the sample.

[0050] In this embodiment, the inner diameter of the outer cylinder hoop 8 is equal to the outer diameter of the outer cylinder mold 5, the outer diameter of the supporting cylinder 7 is equal to the inner diameter of the inner cylinder mold 6, and the supporting cylinder 7 enters and exits the inner cylinder mold 6 through the column.

[0051] The dimensional matching between the outer cylinder hoop and the supporting cylinder ensures tight constraint and reliable support of the mold, facilitates assembly and disassembly, and improves operational convenience and sample preparation repeatability.

[0052] In this embodiment, a fixed base 1 is provided below the base 4, and a cylinder 2 is provided on the fixed base. The sample loading structure and the compaction structure are detachably installed on the cylinder 2 by fixing bolts 3.

[0053] The fixed base and cylinder provide a stable support platform. The material feeding and compaction structure is adjustable and fixed by fixing bolts, allowing for flexible height adjustment, thereby controlling the sample drop distance and compaction position and optimizing sample preparation parameters.

[0054] In this embodiment, the fixed base 1 and the base 4 are concentrically arranged, and two cylinders 2 are symmetrically arranged on both sides of the base 4. The cylindrical tube 9 of the sample assembly structure is provided with fixing bolts 3 to connect with the cylinders 2.

[0055] In this embodiment, the cylinder 2 is provided with a sliding sleeve connected to the cylindrical tube 9, and the fixing bolt 3 passes through the sliding sleeve and is connected to the cylinder 2.

[0056] In this embodiment, the sample loading structure includes a cylindrical tube 9 and a positive funnel 10, a cylindrical channel 11, and an inverted funnel 12 arranged sequentially from top to bottom inside the cylindrical tube 9. The inverted funnel 12 is provided with a conical baffle 13, which is fixed inside the cylindrical tube 9 by a thin rod 14.

[0057] The dumbbell structure formed by the positive funnel, cylindrical channel and negative funnel, combined with the conical baffle, ensures that the material is evenly distributed during sample loading, avoiding the problem of uneven filling by manual pouring, and improving the uniformity of sample loading and the consistency of the sample.

[0058] In this embodiment, the conical baffle 13 includes a conical part and a cylindrical part arranged at the top and bottom. The conical part and the inverted funnel form an inclined discharge channel, and the cylindrical part and the cylindrical tube 9 form a cylindrical discharge channel 15.

[0059] In this embodiment, an outwardly extending inclined discharge channel is formed between the conical baffle 13 and the anti-funnel 12, and the bottom of the cylindrical tube 9 is a cylindrical discharge channel 15 that communicates with the inclined discharge channel.

[0060] The design of the inclined discharge channel and the cylindrical discharge channel 15 further optimizes the material flow path, ensuring that the material evenly covers the sample preparation space, reducing local accumulation or gaps, and improving the sample loading quality.

[0061] In this embodiment, the cylindrical discharge channel 15 is consistent with the shape of the sample preparation space.

[0062] In this embodiment, the compaction structure includes a hollow compaction disc 16, a two-hole disc 18, and a four-hole disc 19 arranged sequentially from bottom to top. A cylinder 17 is provided on the hollow compaction disc 16. The cylinder 17 passes through the four-hole disc 19 and connects to the two-hole disc 18. The four-hole disc 19 is fixed in position, while the two-hole disc 18 is movable. A force transmission bolt 20 is provided between the two-hole disc 18 and the four-hole disc 19. By rotating the force transmission bolt 20, the hollow compaction disc 16 can be raised and lowered.

[0063] This compaction structure transmits force through force-transmitting bolts, and the hollow compaction disc ensures uniform pressure distribution, achieving efficient and uniform compaction. This avoids the problem of uneven pressure in traditional compaction and improves the density and uniformity of the sample.

[0064] In this embodiment, the hollow compaction disc 16 is fitted with the inner cylinder mold 6 with a clearance.

[0065] In this embodiment, the force transmission bolt 20 is threadedly connected to the two-hole disc 18 and the four-hole disc 19.

[0066] The threaded connection ensures stable transmission and precise control of the force-transmitting bolts, allowing for gradual application of pressure. The compaction process is controllable and repeatable, further guaranteeing the uniformity of compaction and the quality of the sample.

[0067] In this embodiment, the base 4 is placed inside the fixed base 1, and the outer diameter of the base 4 is smaller than the inner diameter of the fixed base 1.

[0068] In this embodiment, the outer cylinder mold 5 and the inner cylinder mold 6 are secured to the base 4.

[0069] In this embodiment, the supporting cylinder 7 is placed inside the inner cylinder mold 6 to support the inner cylinder mold 6, and the outer cylinder hoop 8 is fitted on the assembled outer cylinder mold 5 to constrain the outer cylinder.

[0070] In this embodiment, the positive funnel 10, the cylindrical channel 11, and the negative funnel 12 are sequentially connected inside the cylindrical tube 9 to form a dumbbell-like structure.

[0071] In this embodiment, the conical baffle 13 is connected to the thin rod 14 and fixed inside the cylindrical tube 9.

[0072] In this embodiment, the cylindrical tube 9 can be slid to any position on the cylinder 2 and fixed by tightening or loosening the fixing bolts 3.

[0073] In this embodiment, the hollow compaction disc 16 is connected to the round rod 17, and the round rod 17 passes through two symmetrical round holes in the four-hole disc 19.

[0074] In this embodiment, the two-hole disc 18 is pressed on the two round rods 2 and connected to the four-hole disc 19 by two force transmission bolts 20.

[0075] In this embodiment, the two-hole disc 18 and the four-hole disc 19 can be moved and fixed on the cylinder 2 by adjusting the fixing bolt 3.

[0076] In this embodiment, the outer cylinder mold is clamped on the inner wall of the outer circle of the base to form an outer circle, and the inner cylinder mold is clamped on the groove of the inner circle of the base to form an inner circle.

[0077] In this embodiment, the supporting cylinder is screwed into the base through a column to support the inner cylinder mold, and the outer cylinder hoop is fitted onto the assembled outer cylinder mold to constrain the outer cylinder.

[0078] Example 2:

[0079] A method for preparing a hollow cylinder sample, the method being based on the apparatus described in Embodiment 1, the method comprising the following steps:

[0080] S1. Install the sample loading structure above the sample preparation space, pour the material into the sample loading structure, and after the material is uniformly processed by the sample loading structure, it falls into the sample preparation space to complete the sample loading.

[0081] S2. Remove the sample loading structure and install the compaction structure above the sample preparation space after loading.

[0082] S3. The compaction end of the compaction structure moves downward to compact the material in the sample preparation space, completing one compaction, and then the compaction structure is removed.

[0083] S4. Repeat steps S1-S3 until the sample preparation is completed. Disassemble the outer cylinder mold 5 and the inner cylinder mold 6 to obtain a hollow cylinder.

[0084] This method, through layered sample loading and compaction, combined with the uniform feeding and controllable compaction of the device, ensures high uniformity and density of hollow cylindrical samples, significantly improving sample preparation efficiency and repeatability, and reducing human error.

[0085] In this embodiment, before step S1, the method further includes: placing the base 4 inside the fixed base 1; clamping the inner cylinder mold 6 in the inner circular groove of the base 4; then screwing the support cylinder 7 into the fixed base 1 through the column to support the inner cylinder mold 6; and putting the outer cylinder hoop 8 on the assembled outer cylinder mold 5 to constrain the outer cylinder.

[0086] In this embodiment, step S1 specifically involves: passing the round hole of the fixing bolt 3 of the sample mounting structure through the cylinder 2, moving it to the required height, and then tightening the bolt 3 to fix it on the cylinder 2;

[0087] The soil is poured into the positive funnel 10 in layers, and then flows into the inverted funnel 12 below at the cylindrical channel 11. Under the action of the conical baffle 13, the soil is evenly distributed. When it flows to the thin rod 14, the disturbance to the soil flow is negligible because the thin rod 14 is very thin. The cylindrical discharge channel 15 at the bottom of the cylindrical cylinder 9 prevents soil particles from flying out.

[0088] In this embodiment, step S2 specifically involves: loosening the fixing bolts 3 and removing the sample structure after each layer of soil is filled;

[0089] Place the hollow compaction disc 16, together with the round rod 17, onto the soil sample in the sample preparation space;

[0090] Next, pass the two smooth round holes of the four-hole disc 19 through the two round rods 17, and pass the round holes of the fixing bolts 3 of the four-hole disc 19 through the two round cylinders 2. Tighten the fixing bolts 3 to fix the four-hole disc 19 in the required position.

[0091] Insert the fixing bolt 3 of the two-hole disc 18 into the cylinder 2, slide the two-hole disc 18 above the two round rods 17, and then completely loosen the fixing bolt 3.

[0092] Screw the two force-transmitting bolts 20 into the threaded holes of the two-hole disc 18 simultaneously, and continue to screw the bolts into the two threaded holes of the four-hole disc 19 until the nut contacts the two-hole disc 18.

[0093] In this embodiment, step S3 specifically involves the following steps: At this time, when the force transmission bolt 20 is tightened simultaneously, the soil sample will be subjected to the squeezing action of the hollow compaction disc 18. Since the pressure exerted by the bolt can be very large, and the hollow disc makes the force more uniform, it can be compacted better.

[0094] After one compaction is completed, loosen the fixing bolt 3 and remove them one by one.

[0095] 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, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hollow cylindrical sample preparation device, characterized in that: The sample preparation includes an outer cylinder mold (5), an inner cylinder mold (6), a sample loading structure, and a compaction structure. The outer cylinder mold (5) is fitted around the outer circumference of the inner cylinder mold (6), and a hollow cylindrical sample preparation space is formed between the outer cylinder mold (5) and the inner cylinder mold (6). Both the outer cylinder mold (5) and the inner cylinder mold (6) are formed into a cylindrical shape by multiple arc-shaped plates. The sample loading structure is detachably installed above the sample preparation space to uniformly drop materials into the sample preparation space. The compaction structure is detachably installed above the sample preparation space, and the compaction end of the compaction structure can be raised and lowered to compact the materials in the sample preparation space.

2. The hollow cylindrical sample preparation device according to claim 1, characterized in that: The outer cylinder mold (5) has a base (4) at its bottom. The base (4) has two limiting grooves, one inside and one outside, which limit the bottom of the outer cylinder mold (5) and the other inside the inner cylinder mold (6).

3. The hollow cylindrical sample preparation device according to claim 2, characterized in that: The outer cylinder mold (5) is fitted with an outer cylinder hoop (8) on its outer periphery. The inner cylinder mold (6) is provided with a support cylinder (7) for supporting the inner cylinder mold (6). The support cylinder (7) is provided with a column, which passes through the support cylinder (7) and is connected to the base (4).

4. The hollow cylindrical sample preparation device according to claim 3, characterized in that: The inner diameter of the outer cylinder hoop (8) is equal to the outer diameter of the outer cylinder mold (5), and the outer diameter of the supporting cylinder (7) is equal to the inner diameter of the inner cylinder mold (6). The supporting cylinder (7) enters and exits the inner cylinder mold (6) through the column.

5. The hollow cylindrical sample preparation device according to claim 2, characterized in that: The base (4) is provided with a fixed base (1) below it, and a cylinder (2) is provided on the fixed base. The sample loading structure and the compaction structure are detachably installed on the cylinder (2) by fixing bolts (3).

6. The hollow cylindrical sample preparation device according to claim 1, characterized in that: The sample loading structure includes a cylindrical tube (9) and a positive funnel (10), a cylindrical channel (11) and a negative funnel (12) arranged sequentially from top to bottom inside the cylindrical tube (9). The negative funnel (12) is provided with a conical baffle (13), which is fixed inside the cylindrical tube (9) by a thin rod (14).

7. The hollow cylindrical sample preparation device according to claim 6, characterized in that: An outwardly extending inclined discharge channel is formed between the conical baffle (13) and the anti-funnel (12), and the bottom of the cylindrical tube (9) is a cylindrical discharge channel (15) connected to the inclined discharge channel.

8. The hollow cylindrical sample preparation device according to claim 1, characterized in that: The compaction structure includes a hollow compaction disc (16), a two-hole disc (18), and a four-hole disc (19) arranged sequentially from bottom to top. A cylinder (17) is provided on the hollow compaction disc (16). The cylinder (17) passes through the four-hole disc (19) and connects to the two-hole disc (18). The four-hole disc (19) is fixed in position, while the two-hole disc (18) is movable. A force transmission bolt (20) is provided between the two-hole disc (18) and the four-hole disc (19). By rotating the force transmission bolt (20), the hollow compaction disc (16) can be raised and lowered.

9. A hollow cylindrical sample preparation device according to claim 8, characterized in that: The force transmission bolt (20) is threadedly connected to the two-hole disc (18) and the four-hole disc (19).

10. A method for preparing a hollow cylindrical sample, characterized in that: The method is based on the apparatus according to any one of claims 1-9, and the method includes the following steps: S1. Install the sample loading structure above the sample preparation space, pour the material into the sample loading structure, and after the material is uniformly processed by the sample loading structure, it falls into the sample preparation space to complete the sample loading. S2. Remove the sample loading structure and install the compaction structure above the sample preparation space after loading. S3. The compaction end of the compaction structure moves downward to compact the material in the sample preparation space, completing one compaction, and then the compaction structure is removed. S4. Repeat steps S1-S3 until the sample preparation is completed. Disassemble the outer cylinder mold (5) and the inner cylinder mold (6) to obtain a hollow cylinder.

Images