A subgrade layered sampling device

Abstract

The utility model belongs to the roadbed soil sampling technical field, concretely relates to a kind of roadbed layered sampling device to solve the problem that current sampling device cannot be layered sampling. Including sampling assembly and power component;Sampling assembly includes inner cylinder and outer cylinder, outer cylinder is slidably sleeved in inner cylinder, and its axial length is greater than the axial length of inner cylinder;Power component includes driving mechanism, attitude conversion mechanism and contact mechanism;Attitude conversion mechanism includes switching cylinder, switching cylinder has first position connected with contact mechanism, and second position connected with driving mechanism;When switching cylinder is in first position, driving mechanism keeps vertical under the circumferential limiting action of switching cylinder, to be able to exert axial force to inner cylinder or outer cylinder;When switching cylinder is in second position, switching cylinder removes the circumferential limiting of driving mechanism, and driving mechanism can deviate vertical direction to be able to exert lateral component force to inner cylinder or outer cylinder.The present scheme realizes layered sampling.

Description

Technical Field

[0001] This utility model belongs to the field of roadbed soil sampling technology, and specifically relates to a roadbed layered sampling device. Background Technology

[0002] As the core load-bearing layer in the road structure that directly supports the pavement system and vehicle dynamic loads, the quality of the roadbed is the fundamental guarantee for the overall service performance and long-term stability of the road. The roadbed is a composite structural system constructed by filling and compacting the fill material layer by layer. The compaction quality parameters of each layer (such as the thickness of the surface loose soil and loose transition layer, and the density of the compacted layer) directly determine the overall bearing strength, deformation resistance, and water stability of the roadbed.

[0003] During the quality control of roadbed construction, it is necessary to conduct on-site sampling and analysis of the roadbed to ensure that the actual performance of the roadbed meets the design bearing requirements, thereby avoiding quality defects such as uneven settlement and early cracking during the road operation period.

[0004] In existing technologies, single-cylinder coring machines are commonly used to sample soil by rotating a long cylinder. However, the sampling process applies strong lateral disturbance and vertical compressive stress to the soil, causing particle movement and mixing between the surface loose soil and the compacted soil layer. This severely damages the original compaction state and particle arrangement structure of the soil layer, making it impossible for the obtained core sample to truly reflect the layered structure and compaction status of the soil on site, thus affecting the accurate assessment of the roadbed construction quality. Utility Model Content

[0005] In order to solve the above-mentioned problems in the prior art, namely, the strong lateral disturbance and vertical compressive stress applied to the soil during the sampling process, which causes particle movement and mixing between the surface loose soil and the compacted soil layer, this utility model provides a roadbed layer sampling device.

[0006] A roadbed stratified sampling device includes a sampling component and a power component;

[0007] The sampling assembly includes an inner cylinder and an outer cylinder, wherein the outer cylinder is slidably fitted onto the inner cylinder, and its axial length is greater than that of the inner cylinder;

[0008] The power assembly includes a drive mechanism, an attitude transformation mechanism, and a contact mechanism arranged sequentially from top to bottom, with the attitude transformation mechanism hinged to the contact mechanism.

[0009] The attitude transformation mechanism includes a switching cylinder, which has a first position connected to the contact mechanism and a second position connected to the drive mechanism.

[0010] When the switching cylinder is in the first position, the driving mechanism remains vertical under the circumferential limiting action of the switching cylinder, thereby being able to apply an axial force to the inner cylinder or the outer cylinder, so that the inner cylinder or the outer cylinder moves downward to achieve sampling;

[0011] When the switching cylinder is in the second position, the switching cylinder releases the circumferential limit on the driving mechanism, and the driving mechanism can deviate from the vertical direction so as to apply a lateral component force to the inner cylinder or the outer cylinder, so as to separate the soil from the inner cylinder or the outer cylinder.

[0012] Furthermore,

[0013] The inner cylinder includes an inner cylinder shell and an inner cylinder positioning bracket disposed within the inner cylinder shell. The length of the inner cylinder positioning bracket is shorter than that of the inner cylinder shell, and the inner cylinder positioning bracket is provided with a tapered hole that gradually narrows from top to bottom.

[0014] The outer cylinder includes an outer cylinder shell and an outer cylinder positioning bracket disposed outside the outer cylinder shell. The length of the outer cylinder positioning bracket is shorter than that of the outer cylinder shell, and the outer cylinder positioning bracket is provided with a tapered hole that gradually narrows from top to bottom.

[0015] Furthermore,

[0016] The sampling assembly includes multiple outer cylinders;

[0017] The outer diameters of the multiple outer cylinders increase sequentially along the expansion sequence, and they are coaxially assembled in order of increasing outer diameter.

[0018] Furthermore,

[0019] The contact mechanism includes a hinged seat;

[0020] The attitude transformation mechanism includes an angle adjustment shaft, the upper end of which is connected to the drive mechanism and the lower end of which is connected to the hinge seat.

[0021] When the switching cylinder is in the second position, the switching cylinder releases the circumferential lock on the angle adjustment shaft, thereby allowing the angle adjustment shaft to rotate relative to the hinge seat.

[0022] Furthermore,

[0023] The contact mechanism further includes a first threaded portion, which is located below the hinge seat.

[0024] When the switching cylinder is in the first position, the switching cylinder is connected to the first screw connection.

[0025] Furthermore,

[0026] The drive mechanism further includes a second threaded portion, which is located above the first threaded portion;

[0027] When the switching cylinder is in the second position, the switching cylinder is connected to the second screw connection.

[0028] Furthermore,

[0029] The drive mechanism includes a guide shaft, an impact support, and an impact hammer;

[0030] The guide shaft extends downward to connect with the angle adjustment shaft;

[0031] The impact support is fitted onto the guide shaft and is located above the second threaded connection.

[0032] The impact hammer is slidably mounted on the guide shaft and located above the impact support, for reciprocating impacts on the impact support.

[0033] Furthermore,

[0034] The contact mechanism includes a force-guiding plate and a force-guiding socket located below the force-guiding plate;

[0035] The force-guiding plate is connected to the first screw connection at the top and to the force-guiding socket at the bottom. The force-guiding socket is provided with a tapered surface that gradually tapers from top to bottom.

[0036] Furthermore,

[0037] The contact mechanism also includes a rotary base, which is fitted onto the force guide plate and fixedly connected to the force guide socket.

[0038] The force-guiding plate can rotate freely around its own axis within the rotating base.

[0039] Furthermore,

[0040] The inner cylinder shell is inserted into the roadbed at one end with an initial guide tilt angle;

[0041] The outer cylinder shell is inserted into the roadbed at one end with a progressive guide angle.

[0042] The beneficial effects of this utility model are:

[0043] The roadbed layered sampling device, by setting up slidingly fitted inner and outer cylinders with different axial lengths, in conjunction with the drive mechanism, attitude transformation mechanism, and contact mechanism arranged sequentially from top to bottom in the power assembly, and by utilizing the switching cylinder in the attitude transformation mechanism to switch between the first and second positions, fundamentally changes the force transmission path and direction constraints in both sampling and demolding working modes.

[0044] When the switching cylinder is in the first position, the switching cylinder is connected to the contact mechanism and forms a circumferential limit on the drive mechanism, forcing the drive mechanism to maintain a vertical posture, thereby enabling the axial force generated by the drive mechanism to be stably applied to the inner or outer cylinder, causing it to move vertically downward to complete the stratified sampling.

[0045] When the switching cylinder is switched to the second position, the switching cylinder is connected to the drive mechanism and the circumferential limit on the drive mechanism is released. At this time, since the attitude change mechanism and the contact mechanism are hinged, the drive mechanism can deviate from the vertical direction, thereby applying a lateral component force to the inner or outer cylinder that has been inserted into the soil, so that the soil sample and the cylinder wall are relatively loose and easy to separate.

[0046] Based on the above mechanism, the device utilizes a layered operation method in sampling mode, where the inner cylinder prioritizes collecting surface soil samples and the outer cylinder subsequently slides along the outer wall of the inner cylinder to collect deep soil samples. This fundamentally avoids the particle movement and mixing problems caused by lateral disturbance and vertical compression stress between the surface loose soil and the compacted soil layer during traditional single-cylinder sampling. At the same time, the force direction can be changed in demolding mode by simply switching the position of the switching cylinder, achieving effective separation of the sampling cylinder from the surrounding soil with a smaller lateral component force. Thus, while ensuring the in-situ representativeness and stratification integrity of soil samples at different depths, the device significantly improves the convenience and success rate of sampling operations. Attached Figure Description

[0047] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0048] Figure 1 This is a schematic diagram of the overall structure of the roadbed layered sampling device provided in this embodiment;

[0049] Figure 2 for Figure 1 Sectional view of AA;

[0050] Figure 3 This is an exploded view of the roadbed layered sampling device provided in this embodiment;

[0051] Figure 4 This is a schematic diagram of the power component (excluding the switching cylinder) in the roadbed layered sampling device provided in this embodiment;

[0052] Figure 5 This is a schematic diagram of the contact mechanism in the roadbed layered sampling device provided in this embodiment;

[0053] Figure 6 for Figure 5 Diagram of BB in the middle;

[0054] Figure 7This is a schematic diagram of the sampling component.

[0055] Figure 8 for Figure 7 CC section view;

[0056] Figure 9 This is a schematic diagram of the inner cylinder structure;

[0057] Figure 10 This is a schematic diagram of the outer cylinder.

[0058] icon:

[0059] 100-Sampling Component;

[0060] 110 - Inner cylinder; 111 - Inner cylinder shell; 112 - Inner cylinder positioning bracket;

[0061] 120 - Outer cylinder; 121 - Outer cylinder shell; 122 - Outer cylinder positioning bracket;

[0062] 200-Power Components;

[0063] 210 - Drive mechanism; 211 - Second screw connection; 212 - Guide shaft; 213 - Impact support; 214 - Impact hammer;

[0064] 220 - Attitude transformation mechanism; 221 - Switching cylinder; 222 - Angle adjustment shaft;

[0065] 230 - Contact mechanism; 231 - Hinge seat; 232 - First screw connection; 233 - Force guide plate; 234 - Force guide socket; 235 - Rotary base. Detailed Implementation

[0066] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0067] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0068] This embodiment discloses a roadbed layered sampling device; please refer to [other documentation / reference]. Figures 1-10The system includes a sampling component 100 and a power component 200. The sampling component 100 includes an inner cylinder 110 and an outer cylinder 120, with the outer cylinder 120 slidably fitted onto the inner cylinder 110 and having an axial length greater than that of the inner cylinder 110. The power component 200 includes a drive mechanism 210, an attitude transformation mechanism 220, and a contact mechanism 230 arranged sequentially from top to bottom. The attitude transformation mechanism 220 is hinged to the contact mechanism 230. The attitude transformation mechanism 220 includes a switching cylinder 221, which has a first position connected to the contact mechanism 230 and a position connected to the drive mechanism 210. The second position is connected to 0; when the switching cylinder 221 is in the first position, the drive mechanism 210 remains vertical under the circumferential limiting action of the switching cylinder 221, so that it can apply an axial force to the inner cylinder 110 or the outer cylinder 120, so that the inner cylinder 110 or the outer cylinder 120 moves downward to achieve sampling; when the switching cylinder 221 is in the second position, the switching cylinder 221 releases the circumferential limiting action of the drive mechanism 210, and the drive mechanism 210 can deviate from the vertical direction so that it can apply a lateral force to the inner cylinder 110 or the outer cylinder 120, so that the soil is separated from the inner cylinder 110 or the outer cylinder 120.

[0069] The roadbed stratified sampling device provided in this embodiment includes two main parts: a sampling component 100 and a power component 200.

[0070] The sampling assembly 100 is used to insert into the roadbed to collect soil samples. It consists of an inner cylinder 110 and an outer cylinder 120. The outer cylinder 120 is slidably coaxially fitted outside the inner cylinder 110, and the axial length of the outer cylinder 120 is greater than the axial length of the inner cylinder 110. This design allows the inner cylinder 110 to mainly collect surface and shallow soil samples, while the outer cylinder 120 can continue to slide down along the outer wall of the inner cylinder 110 to enter deeper undisturbed soil layers for sampling.

[0071] The power assembly 200 provides driving force to the sampling assembly 100. From top to bottom, it includes a drive mechanism 210, an attitude transformation mechanism 220, and a contact mechanism 230. The attitude transformation mechanism 220 and the contact mechanism 230 are hinged, allowing them to rotate relative to each other. The core component of the attitude transformation mechanism 220 is a switching cylinder 221, which has two selectable working positions.

[0072] The first position is the position where the switching cylinder 221 is fixedly connected to the contact mechanism 230. At this time, the switching cylinder 221 forms a circumferential limit on the drive mechanism 210, forcing the drive mechanism 210 to maintain a vertical posture. The impact force generated by the drive mechanism 210 can be transmitted to the inner cylinder 110 or the outer cylinder 120 in a purely axial manner, pushing it to insert vertically downward into the roadbed to complete the sampling.

[0073] The second position is the position where the switching cylinder 221 is fixedly connected to the drive mechanism 210. At this time, the switching cylinder 221 releases the circumferential limit on the drive mechanism 210. Since the attitude change mechanism 220 and the contact mechanism 230 are hinged, the drive mechanism 210 can freely deflect relative to the contact mechanism 230 within a certain solid angle range. The operator can manually tilt the drive mechanism 210 to apply a force with a lateral component (such as lateral knocking or swinging pull) to the inner cylinder 110 or outer cylinder 120 that has been inserted into the soil, so that the friction between the sampling cylinder and the surrounding soil is broken, and the soil sample and the cylinder wall are relatively loosened, so that the entire sampling assembly 100 together with the internal soil sample can be completely pulled out from the roadbed.

[0074] The core working mechanism of this structure is that by physically switching the switching cylinder 221 between two positions, the force transmission path and directional constraints of the power component 200 are changed, realizing the rapid conversion between two working modes: vertical rigid impact sampling and lateral flexible loosening demolding.

[0075] The beneficial effects are as follows: First, in sampling mode, it can ensure the accuracy and stability of the impact direction, avoiding sampling failure or soil disturbance caused by deflection; Second, in demolding mode, by applying a lateral component force, the sampling tube can be pulled out of the dense soil with a smaller total force, avoiding soil sample breakage or tube damage that may occur when pulling directly upwards; Third, the switching operation is simple and quick, without the need to disassemble any fasteners, which greatly improves the efficiency of field sampling.

[0076] As an extension, the first and second positions of the switching cylinder 221 can be achieved by setting two annular grooves of different diameters on the inner wall of the switching cylinder 221. The upper annular groove cooperates with the protrusion on the drive mechanism 210 to achieve circumferential locking, and the lower annular groove cooperates with the protrusion on the contact mechanism 230 to achieve fixed connection; or the switching cylinder 221 itself can be designed as a two-half clamp structure, and its connection state with different components can be changed by tightening or loosening the clamp bolts.

[0077] As an alternative, the circumferential limiting function of the switching cylinder 221 can be replaced with an axial pin limiting function. That is, when the switching cylinder 221 is in the first position, the pin is inserted into the pin hole of the drive mechanism 210 to prevent it from rotating; when it is in the second position, the pin is pulled out, and the switching cylinder 221 and the drive mechanism 210 are connected by a snap-fit. Alternatively, an electromagnetic switching method can be used, in which the switching cylinder 221 is attracted and separated from different components by the on and off state of the electromagnet, thereby achieving electric switching.

[0078] Regarding the structure of the inner cylinder 110 and the outer cylinder 120, specifically:

[0079] The inner cylinder 110 includes an inner cylinder shell 111 and an inner cylinder positioning bracket 112 disposed inside the inner cylinder shell 111. The length of the inner cylinder positioning bracket 112 is shorter than that of the inner cylinder shell 111, and the inner cylinder positioning bracket 112 is provided with a tapered hole that gradually narrows from top to bottom. The outer cylinder 120 includes an outer cylinder shell 121 and an outer cylinder positioning bracket 122 disposed outside the outer cylinder shell 121. The length of the outer cylinder positioning bracket 122 is shorter than that of the outer cylinder shell 121, and the outer cylinder positioning bracket 122 is provided with a tapered hole that gradually narrows from top to bottom.

[0080] The inner cylinder 110 consists of an inner cylinder shell 111 and an inner cylinder positioning bracket 112. The inner cylinder positioning bracket 112 is fixedly installed inside the upper part of the inner cylinder shell 111, and its axial length is less than the total length of the inner cylinder shell 111. Thus, when the inner cylinder 110 is inserted into the roadbed, the lower end of the inner cylinder shell 111 penetrates the soil layer, while the inner cylinder positioning bracket 112 is located in the upper part that does not penetrate the soil layer. The center of the inner cylinder positioning bracket 112 has a tapered hole that gradually tapers from top to bottom, meaning the upper diameter of the tapered hole is larger than the lower diameter. Similarly, the outer cylinder 120 consists of an outer cylinder shell 121 and an outer cylinder positioning bracket 122. The outer cylinder positioning bracket 122 is fixedly installed outside the upper part of the outer cylinder shell 121, and its axial length is also less than the total length of the outer cylinder shell 121. The outer cylinder positioning bracket 122 also has a tapered hole that gradually tapers from top to bottom. In actual use, the lower end of the contact mechanism 230 is equipped with a tapered plug or tapered socket that matches the aforementioned tapered hole. When the contact mechanism 230 is connected to the inner cylinder 110 or the outer cylinder 120, the conical plug is inserted into the conical hole. Since the conical surface gradually narrows from top to bottom, the two will automatically center and press together under the action of gravity and impact force, so as to achieve reliable axial force transmission.

[0081] The beneficial effects of this structure are: the tapered hole mating structure has the characteristics of self-centering, self-locking and impact resistance. It will not loosen or become eccentric even under repeated impact loads. At the same time, it can be separated by simply lifting axially during disassembly and assembly without rotation or the use of tools, making it very suitable for rapid field operations.

[0082] As an alternative, the tapered hole can be replaced by a spherical hole and a spherical head to achieve a larger adaptive adjustment angle; or an elastic pad or rubber layer can be set on the inner wall of the tapered hole to absorb impact vibration and reduce wear on the mating surfaces; or the tapered hole can be designed as a segmented structure, with a cylindrical guide section at the top and a tapered locking section at the bottom to improve the guiding accuracy during initial insertion.

[0083] In an optional embodiment, the sampling component includes multiple outer cylinders 120; the outer diameters of the multiple outer cylinders 120 increase sequentially along the expansion order, and they are coaxially assembled in order of increasing outer diameter.

[0084] Specifically, the outer cylinder 120 with the smallest outer diameter is directly fitted onto the outside of the inner cylinder 110, with its inner diameter slightly larger than the outer diameter of the inner cylinder 110, leaving a sliding gap between them; the outer cylinder 120 with the second smallest outer diameter is fitted onto the outside of the outer cylinder 120 with the smallest outer diameter, and so on, with the outer cylinder 120 with the largest outer diameter located at the outermost layer. The axial length of each outer cylinder 120 can be the same, or it can gradually increase from the inner layer to the outer layer, but usually the outermost outer cylinder 120 is the longest, to ensure that each outer cylinder 120 can reach its designed depth when sampling layer by layer.

[0085] In actual sampling operations, the power unit 200 is first used to drive the inner cylinder 110 to insert into the roadbed and collect surface soil samples (e.g., 0-20cm depth). Then, the power unit 200 is removed, and the first outer cylinder 120 (minimum outer diameter) is placed over the upper part of the inner cylinder 110 that is exposed above the roadbed. The contact mechanism 230 is connected to the outer cylinder positioning bracket 122 of the first outer cylinder 120, driving the first outer cylinder 120 to slide downward along the outer wall of the inner cylinder 110 and insert into the roadbed to collect the second layer of soil samples (e.g., 20-40cm depth). Next, the second outer cylinder 120 (second smallest outer diameter) is replaced and placed over the outside of the first outer cylinder 120, driving it downward to collect samples. This process is repeated until all outer cylinders 120 are inserted to the predetermined depth. In this way, each sampling cylinder enters the soil layer under the guidance of the previous one, and each sampling cylinder only collects soil samples within its corresponding depth range. Soil samples at different depths are completely separated by the cylinder walls, preventing particle movement or interlayer mixing.

[0086] The beneficial effects of this structure are that it enables in-situ, undisturbed, and simultaneous sampling of soil layers at different depths in the roadbed. Each soil sample retains its original compaction state and particle arrangement structure, providing highly representative samples for subsequent indoor tests such as compaction degree, moisture content, and particle size analysis.

[0087] As an alternative, guide rings or anti-friction bushings can be installed between multiple outer cylinders 120 to reduce interlayer sliding friction; the insertion end of each outer cylinder 120 can be designed with different cutting edge angles to adapt to the hardness changes of different soil layers; the axial lengths of the outermost few outer cylinders 120 can also be designed to be equal to achieve simultaneous advancement of multiple layers and improve sampling efficiency.

[0088] Regarding the attitude transformation principle of the attitude transformation mechanism 220, specifically:

[0089] The contact mechanism 230 includes a hinge seat 231; the attitude transformation mechanism 220 includes an angle adjustment shaft 222, the upper end of which is connected to the drive mechanism 210, and the lower end of which is connected to the hinge seat 231. When the switching cylinder 221 is in the second position, the switching cylinder 221 releases the circumferential lock on the angle adjustment shaft 222, thereby allowing the angle adjustment shaft 222 to rotate relative to the hinge seat 231. The hinge seat 231 can be a base with a U-shaped fork or a spherical groove. The upper end of the angle adjustment shaft 222 is fixedly connected to the drive mechanism 210 or integrally formed, and the lower end of the angle adjustment shaft 222 is connected to the hinge seat 231 by a hinge. For example, the lower end of the angle adjustment shaft 222 is provided with a hinge ball head or a cylindrical horizontal shaft, which is placed in the corresponding groove of the hinge seat 231 to form a ball joint or a cylindrical joint.

[0090] When the switching cylinder 221 is in the first position, the switching cylinder 221 is sleeved on the outside of the angle adjustment shaft 222. The non-circular cross section (e.g., hexagon) of the inner wall can cooperate with the corresponding non-circular segment on the angle adjustment shaft 222 to prevent the angle adjustment shaft 222 from rotating relative to the switching cylinder 221. Since the switching cylinder 221 is fixed to the contact mechanism 230 at this time, the angle adjustment shaft 222 and the drive mechanism 210 also cannot rotate relative to the contact mechanism 230 and maintain a vertical posture.

[0091] When the switching cylinder 221 is switched to the second position, it disengages from the adjusting shaft 222, releasing the circumferential lock on the adjusting shaft 222. The adjusting shaft 222 can then rotate freely within the hinge seat 231 (it can rotate omnidirectionally in the case of a ball joint, and can swing in a plane in the case of a cylindrical hinge). At this time, the operator can hold the handle of the drive mechanism 210 and tilt it around the hinge point, thereby applying a lateral force to the sampling cylinder that has been inserted into the soil below.

[0092] The advantages of this structure are as follows: the drive mechanism 210 can be switched between rigid locking and hinged free states simply by moving the switching cylinder 221 axially, resulting in a compact structure and intuitive operation; the hinged method can withstand large lateral bending moments and impact forces, making it suitable for use in harsh outdoor environments. As an alternative, the hinge seat 231 can adopt a universal joint structure, with the lower end of the adjusting shaft 222 connected to one shaft of the universal joint, and the other shaft of the universal joint connected to the contact mechanism 230, achieving deflection in two vertical planes; alternatively, a spring reset structure can be set between the adjusting shaft 222 and the hinge seat 231, so that when the switching cylinder 221 is released from its limit, the adjusting shaft 222 automatically returns to the vertical position, facilitating the next sampling.

[0093] The switching cylinder 221 is fixed in the first position in the following way:

[0094] The contact mechanism 230 also includes a first threaded portion 232, which is located below the hinge seat 231. When the switching cylinder 221 is in the first position, the switching cylinder 221 is connected to the first threaded portion 232. Specifically, the first threaded portion 232 can be an externally threaded cylindrical section or an internally threaded hole. The lower end of the inner wall of the switching cylinder 221 or the bottom extension of the switching cylinder 221 is provided with a matching thread. When the switching cylinder 221 is in the first position, the operator screws the switching cylinder 221 downwards onto the first threaded portion 232. At this time, the switching cylinder 221 not only circumferentially limits the angle adjustment shaft 222 through the non-circular section of its inner wall, but also forms a rigid fixation with the contact mechanism 230 through the threaded connection. Meanwhile, since the first threaded part 232 is located below the hinge seat 231, when the switching cylinder 221 is tightened with the first threaded part 232, the entire switching cylinder 221, together with its internal angle-adjusting shaft 222 and the upper drive mechanism 210, is fixed to the contact mechanism 230 as a rigid whole, ensuring efficient and stable transmission of impact force during sampling. The beneficial effects of this structure are: the threaded connection provides a reliable and detachable fixing method, capable of withstanding repeated impact vibrations without loosening; at the same time, the threaded connection itself is an axial tensioning mechanism, which can eliminate the gap at the hinge seat 231 and improve the overall rigidity. As an alternative, the first threaded part 232 can be replaced with a quick-locking structure, such as setting radial spring beads on the contact mechanism 230 and setting an annular groove on the inner wall of the switching cylinder 221, so that the locking connection can be achieved by axial pushing; or a cam-locking quick-change connector can be used, which can be locked or released by rotating a certain angle.

[0095] The switching cylinder 221 is fixed in the second position in the following way:

[0096] The drive mechanism 210 also includes a second screw connection 211, which is located above the first screw connection 232; when the switching cylinder 221 is in the second position, the switching cylinder 221 is connected to the second screw connection 211.

[0097] The drive mechanism 210 has a second threaded part 211 located below the guide shaft 212 or impact support 213, which is vertically positioned above the first threaded part 232. When switching to the demolding mode, the operator first unscrews the switching cylinder 221 from the first threaded part 232, then moves the switching cylinder 221 upwards so that its internal thread engages with the external thread of the second threaded part 211 and is tightened. At this time, the switching cylinder 221 is fixedly connected to the drive mechanism 210, and the switching cylinder 221 no longer circumferentially limits the angle adjustment shaft 222. Since the switching cylinder 221 is fixed to the drive mechanism 210, the operator can directly hold the handle of the switching cylinder 221 or the drive mechanism 210 to tilt the entire drive mechanism 210, allowing the angle adjustment shaft 222 to rotate freely within the hinge seat 231, thereby applying a lateral force. Simultaneously, the connection between the switching cylinder 221 and the drive mechanism 210 also increases the rigidity and operability of the drive mechanism 210 itself. The advantages of this structure are as follows: In demolding mode, the switching cylinder 221 becomes an extension handle of the drive mechanism 210, facilitating force application by the operator; simultaneously, the switching cylinder 221 does not interfere with the contact mechanism 230, ensuring a sufficiently large tilt angle; the threaded connection design allows switching between the two modes to be done with a simple tightening action, without the need for additional tools. As an alternative, the second threaded part 211 can be located below the impact support 213 and use a reverse thread (left-hand thread) to prevent the switching cylinder 221 from accidentally loosening under impact vibration; alternatively, a locking nut can be provided on the second threaded part 211, which is used to tighten the switching cylinder 221 after it has been tightened, further improving the reliability of the connection.

[0098] Regarding the shape and structure of the drive mechanism 210, specifically:

[0099] The drive mechanism 210 includes a guide shaft 212, an impact support 213, and an impact hammer 214. The guide shaft 212 extends downward to be connected to the angle adjustment shaft 222. The impact support 213 is fitted onto the guide shaft 212 and is located above the second threaded connection 211. The impact hammer 214 is slidably fitted onto the guide shaft 212 and is located above the impact support 213 for reciprocating impacts on the impact support 213.

[0100] This embodiment specifically discloses one implementation of the drive mechanism 210, namely, using a manually operated impact hammer 214 structure. The drive mechanism 210 includes a slender guide shaft 212, an impact support 213 fixedly mounted on the guide shaft 212, and an impact hammer 214 that can slide up and down along the guide shaft 212. The lower end of the guide shaft 212 extends downward and is fixedly connected to the upper end of the angle-adjusting shaft 222 (which can be achieved by threaded connection or welding). The impact support 213 is a metal block with a central hole, the inner hole of which precisely matches the outer diameter of the guide shaft 212, and is fixed to the guide shaft 212 by radial pins or threaded fasteners. The mounting position of the impact support 213 on the guide shaft 212 is above the second threaded connection 211. The impact hammer 214 is a relatively heavy metal sleeve or solid cylinder with a through hole in its center that slides with the guide shaft 212. The impact hammer 214 is mounted on the guide shaft 212 and is located directly above the impact support 213. The upper end of the impact hammer 214 can be equipped with a handle or pull ring for easy gripping by the operator. In use, the operator lifts the impact hammer 214 upwards along the guide shaft 212 to a certain height, then quickly releases it. The impact hammer 214 falls freely under gravity, striking the upper surface of the impact support 213. The impact force is transmitted through the impact support 213 to the guide shaft 212, then sequentially through the angle adjustment shaft 222 and the contact mechanism 230, finally being transmitted to the inner cylinder 110 or the outer cylinder 120, driving it downwards into the soil. Continuous impact sampling can be achieved by repeatedly lifting and lowering the impact hammer 214. The mass and lifting height of the impact hammer 214 can be adjusted according to the soil hardness; for example, less impact energy can be used in soft soil, and more impact energy in hard soil. The advantages of this structure are: it is entirely driven by human power, requiring no external power or air source, making it ideal for field construction sites without power; the impact force is controllable, and the operation is intuitive; the structure is simple, robust, durable, and easy to maintain. As an alternative, the impact hammer 214 can be replaced with an electric impact mechanism, such as installing an electromagnet or linear motor above the guide shaft 212 to lift the impact hammer 214 through electromagnetic attraction and release it automatically, realizing semi-automatic or fully automatic impact sampling; a hydraulic impact mechanism can also be used, which generates impact force by driving the piston to reciprocate through a manual hydraulic pump; a pneumatic impact mechanism can also be used, which is connected to a small air compressor.

[0101] Regarding the shape and structure of the contact mechanism 230, the following should also be added:

[0102] The contact mechanism 230 includes a force-guiding plate 233 and a force-guiding socket 234 located below the force-guiding plate 233. The force-guiding plate 233 is connected to the first screw connection 232 at the top and to the force-guiding socket 234 at the bottom. The force-guiding socket 234 has a tapered surface that gradually tapers from top to bottom. The force-guiding plate 233 is a disc-shaped or cylindrical metal component, with its upper end face or upper inner hole fixedly connected to the first screw connection 232. A force-guiding socket 234 is fixedly connected to the bottom of the force-guiding plate 233. The force-guiding socket 234 can be a sleeve-shaped or columnar component with a tapered surface that gradually tapers from top to bottom at its lower end, forming a tapered boss or tapered plug. The taper of this tapered surface is typically between 1:5 and 1:10, ensuring both self-locking performance and easy separation. During actual sampling, the force guide socket 234 is directly inserted into the conical hole of the inner cylinder positioning bracket 112 or the outer cylinder positioning bracket 122, with the conical surface tightly fitting the inner conical surface of the conical hole. When the impact force is transmitted to the force guide socket 234 through the force guide plate 233, the conical surface fit will evenly distribute the axial force onto the positioning bracket. At the same time, due to the wedge effect of the conical surface, the force guide socket 234 will automatically center itself, ensuring that the axis of the impact force coincides with the axis of the sampling cylinder.

[0103] The beneficial effects of this structure are as follows: the conical surface fit not only enables quick assembly and disassembly and self-centering, but also withstands large impact loads without plastic deformation; the conical surface fit also has a sealing function, preventing external dust or moisture from entering the connection interface. As an alternative, the conical surface on the force-guiding socket 234 can be machined into multiple segments with different tapers, the upper segment with a smaller taper for guiding and the lower segment with a larger taper for locking; it can also be coated with hard alloy or carburized to improve wear resistance; a set of disc springs can also be set between the force-guiding socket 234 and the force-guiding carrier plate 233, so that the conical surface can generate a small amount of elastic compression under impact load, buffering the peak impact force.

[0104] The contact mechanism 230 also includes a rotating base 235, which is fitted onto the force-guiding plate 233 and fixedly connected to the force-guiding socket 234. The force-guiding plate 233 can rotate freely within the rotating base 235 about its own axis. The rotating base 235 is fitted onto the outer circumference of the force-guiding plate 233, and the lower end of the rotating base 235 is fixedly connected to the force-guiding socket 234 (by bolts or welding). Preferably, a sliding bearing or rolling bearing is provided between the outer circumference of the force-guiding plate 233 and the inner hole of the rotating base 235, so that the force-guiding plate 233 can rotate freely within the rotating base 235 about its own vertical axis, while the rotating base 235 and the force-guiding socket 234 fixed thereto do not rotate with the force-guiding plate 233. The practical significance of this design is that, under certain working conditions, auxiliary rotational motion may be needed during sampling to help the sampling cylinder cut through hard soil layers. In this case, the drive mechanism 210 can apply rotational torque, and the force guide plate 233 rotates accordingly. However, due to the presence of the rotating base 235, the rotational torque will not be transmitted to the force guide socket 234, and therefore will not be transmitted to the sampling cylinder, thus avoiding torsional disturbance to the soil sample caused by the rotation of the sampling cylinder. At the same time, in the demolding mode, when the drive mechanism 210 tilts and applies a lateral force, the free rotation of the force guide plate 233 allows the operator to adjust the direction of force application without rotating the entire device.

[0105] It should also be noted that:

[0106] The inner cylinder shell 111 has an initial guide angle at one end inserted into the roadbed; the outer cylinder shell 121 has a progressive guide angle at one end inserted into the roadbed. This embodiment optimizes the geometry of the lower ends (i.e., the ends inserted into the roadbed) of the inner and outer cylinder shells 111. The lower end of the inner cylinder shell 111 has an initial guide angle, typically a chamfer or conical surface of 15° to 30°. Its function is to convert the axial component of the impact force into a radial expansion force when the inner cylinder 110 first contacts the soil, causing the soil to be pushed aside rather than compacted downwards, thereby reducing insertion resistance. The lower end of the outer cylinder shell 121 has a progressive guide angle, which differs from the initial guide angle in that it is a longer, gradually changing conical surface, for example, starting with a small angle of 5° from the cylinder diameter and gradually increasing to 20°. Since the outer cylinder 120 is pushed downward along the narrow annular gap between the outer wall of the inner cylinder 110 and the soil after the inner cylinder 110 has been inserted, the progressive guide angle allows the cutting edge of the outer cylinder 120 to gradually and smoothly cut into the soil, rather than suddenly squeezing the soil, thereby minimizing the disturbance to the soil samples already collected in the inner cylinder 110.

[0107] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0108] The technical solution of this utility model has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

Claims

1. A roadbed layered sampling device, characterized in that: It includes a sampling component (100) and a power component (200); The sampling assembly (100) includes an inner cylinder (110) and an outer cylinder (120). The outer cylinder (120) is slidably fitted onto the inner cylinder (110), and its axial length is greater than that of the inner cylinder (110). The power assembly (200) includes a drive mechanism (210), an attitude transformation mechanism (220), and a contact mechanism (230) arranged sequentially from top to bottom, wherein the attitude transformation mechanism (220) is hinged to the contact mechanism (230); The attitude transformation mechanism (220) includes a switching cylinder (221), which has a first position connected to the contact mechanism (230) and a second position connected to the drive mechanism (210). When the switching cylinder (221) is in the first position, the driving mechanism (210) remains vertical under the circumferential limiting action of the switching cylinder (221), thereby being able to apply an axial force to the inner cylinder (110) or the outer cylinder (120) so that the inner cylinder (110) or the outer cylinder (120) moves downward to achieve sampling; When the switching cylinder (221) is in the second position, the switching cylinder (221) releases the circumferential limit on the driving mechanism (210), and the driving mechanism (210) can deviate from the vertical direction so as to apply a lateral component force to the inner cylinder (110) or the outer cylinder (120) so as to separate the soil from the inner cylinder (110) or the outer cylinder (120).

2. The roadbed stratified sampling device according to claim 1, characterized in that: The inner cylinder (110) includes an inner cylinder shell (111) and an inner cylinder positioning bracket (112) disposed inside the inner cylinder shell (111). The length of the inner cylinder positioning bracket (112) is shorter than that of the inner cylinder shell (111), and the inner cylinder positioning bracket (112) is provided with a tapered hole that gradually narrows from top to bottom. The outer cylinder (120) includes an outer cylinder shell (121) and an outer cylinder positioning bracket (122) disposed outside the outer cylinder shell (121). The length of the outer cylinder positioning bracket (122) is shorter than that of the outer cylinder shell (121), and the outer cylinder positioning bracket (122) is provided with a tapered hole that gradually narrows from top to bottom.

3. The roadbed stratified sampling device according to claim 2, characterized in that: The sampling assembly (100) includes a plurality of the outer cylinders (120); The outer diameters of the multiple outer cylinders (120) increase sequentially along the expansion sequence, and they are coaxially assembled in order of increasing outer diameter.

4. The roadbed stratified sampling device according to claim 3, characterized in that: The contact mechanism (230) includes a hinge seat (231); The attitude transformation mechanism (220) includes an angle adjustment shaft (222), the upper end of which is connected to the drive mechanism (210), and the lower end of which is connected to the hinge seat (231); When the switching cylinder (221) is in the second position, the switching cylinder (221) releases the circumferential lock on the angle adjustment shaft (222), so that the angle adjustment shaft (222) can rotate relative to the hinge seat (231).

5. The roadbed stratified sampling device according to claim 4, characterized in that: The contact mechanism (230) further includes a first threaded portion (232), which is located below the hinge seat (231). When the switching cylinder (221) is in the first position, the switching cylinder (221) is connected to the first screw connection (232).

6. The roadbed stratified sampling device according to claim 5, characterized in that: The drive mechanism (210) further includes a second threaded portion (211), which is located above the first threaded portion (232); When the switching cylinder (221) is in the second position, the switching cylinder (221) is connected to the second screw connection (211).

7. The roadbed stratified sampling device according to claim 6, characterized in that: The drive mechanism (210) includes a guide shaft (212), an impact support (213), and an impact hammer (214); The guide shaft (212) extends downward to connect with the angle adjustment shaft (222); The impact support (213) is fitted onto the guide shaft (212) and is located above the second threaded part (211); The impact hammer (214) is slidably mounted on the guide shaft (212) and located above the impact support (213) for reciprocating impact on the impact support (213).

8. The roadbed stratified sampling device according to claim 7, characterized in that: The contact mechanism (230) includes a force guide plate (233) and a force guide socket (234) located below the force guide plate (233); The force-guiding plate (233) is connected to the first screw connection (232) at the top and to the force-guiding socket (234) at the bottom. The force-guiding socket (234) is provided with a tapered surface that gradually narrows from top to bottom.

9. The roadbed stratified sampling device according to claim 8, characterized in that: The contact mechanism (230) further includes a rotating base (235), which is fitted onto the force guide plate (233) and fixedly connected to the force guide socket (234); The force-guiding plate (233) can rotate freely around its own axis within the rotating base (235).

10. The roadbed stratified sampling device according to claim 9, characterized in that: The inner cylinder shell (111) is inserted into the roadbed at one end with an initial guide tilt angle; The outer cylinder shell (121) is inserted into the roadbed at one end with a progressive guide angle.

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