Fixed-volume automatic sampler for undisturbed soil

Abstract

The invention discloses an undisturbed soil fixed-volume automatic sampler which comprises a sampling tube, the sampling tube further comprises a sample feeding body, an expansion air bag and a controller, and the sample feeding body slides in the sampling tube; the expansion airbag is arranged in the sampling tube, one end of the expansion airbag is connected with the air pump, and the other end is provided with a pressing plate which is provided with a pressure sensor; before sampling, the sampling volume capable of being contained by the sampling tube is controlled by controlling the expansion length of the expansion air bag, during sampling, the sampling tube is inserted into a soil sample to be tested, the sampling tube is pulled out after the soil sample is filled in the containing space, and the sampling tube is connected with the controller. The sampling port of the sampling tube is inserted into the glass bottle, the expansion air bag is controlled to continue to expand, the sample feeding body is driven to move towards the sampling port, all soil samples in the sampling tube are pushed into the glass bottle, the volume difference of the soil samples sampled every time can be reduced, and therefore the accuracy of test data is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of soil detection equipment, in particular to an original soil fixed volume automatic sampler. Background Art

[0002] Soil isotopes are currently widely studied based on the application of stable hydrogen and oxygen isotope analysis methods. A key pretreatment step for stable hydrogen and oxygen isotope analysis in soil is to extract bound water from the soil via vacuum extraction to obtain its hydrogen and oxygen isotope signals. This process places strict demands on sample volume: due to the design standardization of core experimental instrumentation (such as vacuum extraction systems and isotope ratio mass spectrometer autosamplers) and the precision requirements of the operating procedures, samples must be placed in glass vials of specific specifications (typically 12ml). This is a key prerequisite for ensuring consistent subsequent vacuum extraction efficiency, controllable system pressure balance, predictable condensate volume, and meeting the instrument's injection volume requirements.

[0003] However, due to the limited inner diameter of glass bottle openings (typically only about 10 mm), existing soil sampling and transfer methods mostly rely on tools such as glass rods, tweezers, or small spoons to insert or scoop soil into the bottle. This sampling device makes it difficult to precisely control the volume of soil transferred each time. This results in significant variability in the volume of soil sample loaded into the bottle, directly affecting the extraction efficiency and completeness of bound water during the subsequent vacuum extraction process. This leads to significant deviations in the measured soil water isotope ratios, impacting the reliability of the data and the comparability between different samples. Summary of the Invention

[0004] The purpose of the present invention is to provide an automatic sampler for fixed volume of undisturbed soil, which can reduce the difference in soil volume of each sampling, improve the efficiency of soil sample collection and ensure the reliability of experimental data.

[0005] The technical solution of the present invention is: An automatic sampler for fixed volume of original soil, comprising a sampling tube, wherein a slide groove is provided on the side of the sampling tube along its axial direction, and the sampling tube further comprises: a sample delivery body, wherein a slider is provided on the circumferential side, the slider slides in the slide groove, and the side of the slider away from the sample delivery body is an arc-shaped surface, the arc-shaped surface and the curvature of the side of the sampling tube are consistent, and the side of the slider is in sliding contact with the side wall of the slide groove; an expansion airbag is arranged inside the sampling tube, at one end away from the sampling port, one end of the expansion airbag is connected to the air pump, and the other end is provided with a pressure plate, and a pressure sensor is provided on the plate surface of the pressure plate away from the expansion airbag; a controller is arranged on the sampling tube, and the pressure sensor and the air pump are both connected to and communicated with the controller.

[0006] Furthermore, it also includes a guide rod and a spring, the two ends of the guide rod are respectively connected to the two end faces of the slide groove, a through hole is opened on the slider, and the slider is slidably sleeved on the guide rod through the through hole, the spring is sleeved on the guide rod, and the two ends of the spring are respectively connected to the side face of the slider and the end face of the slide groove.

[0007] Furthermore, it includes two sections of sealing cloth, and the two ends of each section of the sealing cloth are respectively connected to the end faces of the slider and the slide groove. The groove surfaces on both sides of the slide groove are grooves along the sliding direction of the slider, and both sides of each section of the sealing cloth slide in the groove.

[0008] Furthermore, the sample delivering body is a cylinder with a cavity therein, and through holes are opened at the center positions of the top and bottom surfaces. The sample delivering body also includes: a motor assembly, including: a dual-axis motor, which is arranged in the cavity of the sample delivering body and is connected and communicated with the controller, the two output shafts of the dual-axis motor extend from the through holes on the top and bottom surfaces of the sample delivering body to the outside of the sample delivering body respectively, and the two output shafts are both sleeved with a second ring gear; two connecting pipes, which are respectively sleeved on the two output shafts, and one end of the connecting pipe is fixedly connected to the motor housing of the dual-axis motor, a section of the tube body of the connecting pipe is a rotating tube structure, the outer side of the rotating tube is sleeved with a third ring gear, and the inner side is sleeved with a fourth ring gear, and the fourth ring gear is meshed with the second ring gear; two rotating rings, the inner ring of each rotating ring is sleeved with a first ring gear, the first ring gear is meshed with the third ring gear, and the outer peripheral surface of the rotating ring is provided with a cleaning structure.

[0009] Furthermore, the cleaning structure includes a carrying ring and multiple groups of bristles, the inner ring surface of the carrying ring is sleeved on the outer ring surface of the rotating ring, the multiple groups of bristles are vertically arranged with the ring surface of the carrying ring, and the multiple groups of bristles are arranged in a circular array on the outer ring surface of the carrying ring, and one end of the multiple groups of bristles abuts against the inner wall of the sampling tube.

[0010] Furthermore, it also includes two closing plates, both of which are circular plates, located at both ends of the dual-axis motor respectively, and the circular surfaces of the closing plates are connected to the connecting pipe, and the center of the circle coincides with the central axis of the connecting pipe.

[0011] Furthermore, the height of the carrying ring is greater than the height of the rotating ring, and the circular plate surface of the closing plate close to the sample sending body is provided with a step structure from its outer circumference toward the center of the circle, and the circular end surface of the sample sending body close to the closing plate is provided with a step structure from its outer circumference toward the center of the circle, and the step structure on the sample sending body and the step structure on the closing plate are symmetrically arranged to form an accommodating space for accommodating the bristles and the carrying ring.

[0012] Furthermore, an annular groove is provided on the annular end surface of the rotating ring, and a positioning roller is provided on the closing plate. The positioning roller is connected to the closing plate by rotating along its own axis, and one end of the positioning roller is inserted into the annular groove.

[0013] Furthermore, the sampling tube is equipped with a sampling tube drive assembly, which includes: a guide plate located on one side of the sampling tube and arranged parallel to the sampling tube, the guide plate having a limit slot formed on its surface along the axial direction of the sampling tube, and support plates at both ends of the guide plate; a lead screw, the ends of which are rotatably connected to the surfaces of the two support plates, and a lead screw motor is configured at the end of the lead screw away from the sampling port of the sampling tube, the lead screw motor being connected and communicating with the controller; a threaded slider sleeved on the lead screw, one side of the threaded slider being fixedly connected to the outer side of the sampling tube, and the other side being slidably connected to the limit slot.

[0014] Furthermore, a fixing nail is provided at the bottom of the support plate near the sampling port of the sampling tube.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention adjusts the length of the expansion airbag through a controller, thereby controlling the distance between the sample delivery body and the sampling port of the sampling tube, thereby controlling the volume of the soil sample obtained each time to be basically fixed. After the sampling of the present invention is completed, the sampling port of the sampling tube is inserted into the glass bottle, and the air pump is started by the controller to continue to expand the expansion airbag. The expansion airbag drives the sample delivery body to move along the axial direction of the sampling tube toward the position of the sampling port, and pushes all the soil samples in the sampling tube into the glass bottle. This not only reduces the volume difference of the soil samples sampled each time and ensures the accuracy of the test data, but also makes the sampler of the present invention more convenient and efficient in collecting and transferring samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a main view of the external structure schematic diagram of Example 1 of the present invention.

[0017] Figure 2 for Figure 1 Schematic diagram of the internal structure.

[0018] Figure 3 This is a front view of the external structure diagram of Example 2 of the present invention.

[0019] Figure 4 This is a top view of a schematic diagram showing the positional relationship between the sample delivery body and the sampling tube of the present invention.

[0020] Figure 5 This is a top view of a schematic diagram showing the positional relationship between the air pump and the sampling tube of the present invention.

[0021] Figure 6 for Figure 3 An enlarged view of the structural schematic diagram of the middle A area.

[0022] Figure 7 for Figure 2 An enlarged view of the structural schematic diagram of the middle B area.

[0023] Figure 8 This is a schematic diagram of the connection relationship between the sample delivery body and the sealing plate of the present invention.

[0024] Figure 9 It is a top view of the structural schematic diagram of the rotating ring of the present invention.

[0025] Among them, 1. sampling tube, 11. slide groove, 12. guide rod, 13. spring, 14. sealing cloth, 2. sample feeding body, 21. slider, 3. rotating ring, 31. cleaning structure, 32. first ring gear, 33. ring groove, 4. closing plate, 41. step structure, 42. positioning roller, 5. dual-axis motor, 51. output shaft, 511. second ring gear, 52. connecting pipe, 53. rotating tube, 531. third ring gear, 532. fourth ring gear, 6. expansion airbag, 61. air pump, 62. pressure plate, 621. pressure sensor, 7. sampling tube drive assembly, 71. threaded slider, 72. guide plate, 73. screw. DETAILED DESCRIPTION

[0026] The following combination Figures 1 to 9 , a detailed description of the specific embodiments of the present invention is provided. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limiting the present invention.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; and in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0028] It should be noted that the circuit connections involved in the present invention all adopt conventional circuit connection methods and do not involve any innovation.

[0029] Example 1 like Figure 1As shown, an original soil fixed volume automatic sampler includes a sampling tube 1, and a chute 11 is opened on the side of the sampling tube 1 along its axial direction. The chute 11 can be multiple, such as Figure 2 As shown, the sampling tube 1 also includes: a sample delivery body 2, an inflation airbag 6 and a controller. A slider 21 is provided on the periphery of the sample delivery body 2. The number of sliders 21 corresponds to the number of chutes 11, and each slider 21 slides in the corresponding chute 11. The side of the slider 21 away from the sample delivery body 2 is an arc-shaped surface. The arc-shaped surface is consistent with the curvature of the side of the sampling tube 1, so that the arc-shaped surface of the slider 21 and the outer peripheral surface of the sampling tube 1 form a flush surface, avoiding soil resistance caused by the slider 21 protruding from the outer peripheral surface of the sampling tube 1 during sampling. The two side surfaces of the slider 21 are in sliding contact with the two side walls of the chute 11 to avoid shaking of the sample delivery body 2 when sliding; the inflation airbag 6 is arranged inside the sampling tube 1 , located at one end away from the sampling port, one end of the expansion airbag 6 is connected to one of the communication ports of the air pump 61, and the other end is provided with a pressure plate 62, and a pressure sensor 621 is provided on the plate surface of the pressure plate 62 away from the expansion airbag 6, and the other communication port of the air pump 61 is located outside the sampling tube 1; the controller is set on the sampling tube 1, and the pressure sensor 621 and the air pump 61 are both connected to the controller for communication. When in use, the air pump 61 is started by the controller to inflate the expansion airbag 6, thereby adjusting the space in the sampling tube 1 that can accommodate the soil sample, thereby controlling the sampling volume of the sampling tube 1. The tube orifice diameter of the sampling tube 1 in this embodiment is 0.8 mm to ensure that the sampling tube 1 can extend into the glass In the glass bottle, the volume of the soil sample obtained each time is controlled by adjusting the distance between the sampling port of the sampling tube 1 and the pressure plate 62 of the expansion airbag 6. The sampling tube 1 is inserted into the soil sample to be tested. When the soil sample entering the sampling tube 1 fills the containing space, it will squeeze the sample delivery body 2 and the pressure sensor 621 on the pressure plate 62. The pressure sensor 621 transmits the pressure value to the controller. The controller is equipped with a display module for displaying the pressure value of the pressure sensor 621. At this time, the sampling tube 1 is pulled out, and the sampling port of the sampling tube 1 is inserted into the glass bottle. The air pump 61 is started by the controller to make the expansion airbag 6 continue to expand. The expansion airbag 6 drives the sample delivery body 2 to take the sample along the axial direction of the sampling tube 1. The position of the sample port is moved to push all the soil samples in the sampling tube 1 into the glass bottle. After that, the air pump 61 is started by the controller to discharge the gas in the expansion airbag 6 and restore the expansion airbag 6 to its initial volume. It is worth noting that the expansion airbag 6 in this embodiment is a cylindrical airbag, which can shrink and expand along the axial direction and can maintain the cylindrical shape when expanding and shrinking. This is the existing technology and will not be elaborated on here. This embodiment adjusts the occupied space of the expansion airbag 6 in the sampling tube 1 to determine the maximum volume of the soil sample that can be collected by the sampling tube 1 each time. This reduces the volume difference of the soil sample sampled each time, thereby ensuring the accuracy of the test data.

[0030] like Figure 1 and Figure 6 As shown, it also includes a guide rod 12 and a spring 13. The two ends of the guide rod 12 are respectively connected to the two end faces of the slide groove 11. A through hole is provided on the slider 21, which is slidably mounted on the guide rod 12 through the through hole. The spring 13 is mounted on the guide rod 12, and the two ends of the spring 13 are respectively connected to the side face of the slider 21 and the end face of the slide groove 11. The slider 21 is supported by the spring 13, and the slider 21 is reset as soon as possible through the recovery of the spring 13, so that the sample sending body 2 is reset until it is close to the pressure plate 62. It is worth noting that the value detected by the pressure sensor 621 at this time is provided by the spring 13. During sampling, when the value of the pressure sensor 621 continues to rise until there is no longer a large increase, it is judged that the sampling tube 1 is filled with soil.

[0031] like Figure 1 and Figure 6 As shown, it also includes two sections of sealing cloth 14, and the two ends of each section of sealing cloth 14 are respectively connected to the end faces of the slider 21 and the slide groove 11. The groove surfaces on both sides of the slide groove 11 are grooves along the sliding direction of the slider 21. Both sides of each section of sealing cloth 14 slide in the groove. When the slider 21 slides, the sealing cloth 14 connected to its top and bottom can be folded and stretched to prevent the soil sample from scattering from the gap between the slider 21 and the slide groove 11 to the outside of the sampling tube 1.

[0032] like Figure 2 and Figure 7As shown, the sample delivery body 2 is a cylinder with a cavity inside, and a through hole is opened at the center position of the top and bottom surfaces. The sample delivery body 2 also includes: a motor assembly and two rotating rings 3. The motor assembly includes: a dual-axis motor 5 and two connecting pipes 52. The dual-axis motor 5 is arranged in the cavity of the sample delivery body 2 and is connected to the controller for communication. The two output shafts 51 of the dual-axis motor 5 extend from the through holes on the top and bottom surfaces of the sample delivery body 2 to the outside of the sample delivery body 2 respectively. The two output shafts 51 are both sleeved with a second ring gear 511; the two connecting pipes 52 are respectively It is sleeved on the two output shafts 51, and one end of the connecting tube 52 is fixedly connected to the motor housing of the dual-axis motor 5. A section of the tube body of the connecting tube 52 is a rotating tube 53 structure. The outer side of the rotating tube 53 is sleeved with a third ring gear 531, and the inner side is sleeved with a fourth ring gear 532. The fourth ring gear 532 is engaged with the second ring gear 511; the inner ring of each of the two rotating rings 3 is sleeved with a first ring gear 32, and the first ring gear 32 is engaged with the third ring gear 531. The outer peripheral surface of the rotating ring 3 is provided with a cleaning structure 31. When the above device is used when pushing samples, the dual-axis motor 5 is started by the controller, and the two output shafts 51 rotate. The fourth ring gear 532 is driven by the second ring gear 511 to rotate the rotating tube 53. The third ring gear 531 rotates synchronously with the rotating tube 53 and drives the first ring gear 32 meshing with it to rotate the rotating ring 3, so that the cleaning structure 31 on the outer peripheral surface of the rotating ring 3 rotates with the output shaft 51 as the axis, and cooperates with the axial movement of the sample sending body 2 to clean the soil sample on the inner wall of the sampling tube 1, preventing the soil sample adhering to the inner wall of the sampling tube 1 from affecting the movement of the sample sending body 2, and at the same time allowing all the soil samples in the sampling tube 1 to enter the glass bottle.

[0033] Preferably, the cleaning structure 31 includes a carrying ring and multiple groups of bristles. The inner ring surface of the carrying ring is sleeved on the outer ring surface of the rotating ring 3. The multiple groups of bristles are arranged vertically to the ring surface of the carrying ring, and the multiple groups of bristles are arranged in a circular array on the outer ring surface of the carrying ring. One end of the multiple groups of bristles abuts the inner wall of the sampling tube 1. The bristles have a certain hardness, and the dense arrangement of the bristles can easily clean and brush off sticky soil samples, so that the inner wall of the sampling tube 1 can be kept smooth to the greatest extent, reducing the influence of the soil sample attached to the inner wall of the sampling tube 1 on the movement of the sample sending body 2.

[0034] like Figure 2 and Figure 8 As shown, it also includes two closing plates 4. Both closing plates 4 are circular plates, which are respectively located at the two ends of the dual-axis motor 5. The circular surfaces of the closing plates 4 are connected to the connecting tube 52, and the center of the circle coincides with the central axis of the connecting tube 52. After the dual-axis motor 5 is started, the rotating ring 3 directly contacts the pressure plate 62, which is not only easy to affect the rotation of the rotating ring 3 but also easy to affect the value of the pressure sensor 621. Therefore, the above problems are avoided by contacting the closing plate 4 fixed to the sample feeding body 2 and the pressure plate 62.

[0035] Preferably, the height of the carrying ring is greater than the height of the rotating ring 3. The carrying ring with a larger height can carry a larger number of bristles, thereby increasing the coverage area of ​​the bristles on the inner wall of the sampling tube 1. The circular plate surface of the closing plate 4 close to the sample delivery body 2 is provided with a step structure 41 from its outer circumference toward the center of the circle, and the circular end surface of the sample delivery body 2 close to the closing plate 4 is provided with a step structure 41 from its outer circumference toward the center of the circle. The step structure 41 on the sample delivery body 2 and the step structure 41 on the closing plate 4 are symmetrically arranged to form an accommodating space for accommodating bristles and the carrying ring.

[0036] like Figure 8 and Figure 9 As shown, an annular groove 33 is provided on the annular end face of the rotating ring 3, and a positioning roller 42 is provided on the closing plate 4. The positioning roller 42 is connected to the closing plate 4 and rotates along its own axis, and one end of the positioning roller 42 is inserted into the annular groove 33. Through the action of the positioning roller 42, the rotating ring 3 always rotates around the output shaft 51 as the axis.

[0037] Example 2 like Figure 2 As shown, the difference from Example 1 is that the sampling tube 1 is equipped with a sampling tube drive assembly 7, which includes a guide plate 72, a lead screw 73, and a threaded slider 71. The guide plate 72 is located on one side of the sampling tube 1 and is arranged parallel to the sampling tube 1. The surface of the guide plate 72 is provided with a limit slot along the axial direction of the sampling tube 1, and support plates are provided at both ends of the guide plate 72. The ends of the lead screw 73 are respectively rotatably connected to the surfaces of the two support plates, and the end of the lead screw 73 away from the sampling port of the sampling tube 1 is equipped with a lead screw motor, which is connected to the controller for communication. The threaded slider 71 is mounted on the lead screw 73. One side of the threaded slider 71 is fixedly connected to the outer side of the sampling tube 1, and the other side is slidably connected to the limit slot. The controller activates the lead screw motor to rotate the lead screw 73, and the sampling tube 1 is uniformly inserted into the soil to be collected through the lead screw transmission principle.

[0038] like Figure 2 As shown, a fixing nail is provided at the bottom of the support plate near the sampling port of the sampling tube 1, and the fixing nail is inserted into the soil to improve the stability of the sampling tube 1 during the insertion into the soil.

[0039] The above disclosures are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. An automatic sampler for fixed volume of undisturbed soil, comprising a sampling tube (1), characterized in that: A sliding groove (11) is provided on the side of the sampling tube (1) along its axial direction. The sampling tube (1) further comprises: The sample delivery body (2) is provided with a slider (21) on its circumferential side, the slider (21) slides in the chute (11), and the side of the slider (21) away from the sample delivery body (2) is an arcuate surface, the arcuate surface and the side curvature of the sampling tube (1) are consistent, and the side of the slider (21) is in sliding contact with the side wall of the chute (11); An expansion airbag (6) is arranged inside the sampling tube (1) and located at one end away from the sampling port. One end of the expansion airbag (6) is connected to the air pump (61), and the other end is provided with a pressure plate (62). A pressure sensor (621) is provided on the plate surface of the pressure plate (62) away from the expansion airbag (6); A controller is provided on the sampling tube (1), and the pressure sensor (621) and the air pump (61) are both connected to and communicate with the controller.

2. The undisturbed soil fixed volume automatic sampler according to claim 1, characterized in that: The invention also includes a guide rod (12) and a spring (13), wherein the two ends of the guide rod (12) are respectively connected to the two end faces of the slide groove (11), the slider (21) is provided with a through hole, and is slidably sleeved on the guide rod (12) through the through hole, the spring (13) is sleeved on the guide rod (12), and the two ends of the spring (13) are respectively connected to the side face of the slider (21) and the end face of the slide groove (11).

3. The undisturbed soil fixed volume automatic sampler according to claim 1, characterized in that: It also includes two sections of sealing cloth (14), both ends of each section of the sealing cloth (14) are respectively connected to the end faces of the slider (21) and the slide groove (11), and the groove surfaces on both sides of the slide groove (11) are grooves along the sliding direction of the slider (21), and both sides of each section of the sealing cloth (14) slide in the grooves.

4. The undisturbed soil fixed volume automatic sampler according to claim 1, characterized in that: The sample delivery body (2) is a cylinder with a cavity inside, and through holes are opened at the center positions of the top and bottom surfaces. The sample delivery body (2) also includes: A motor assembly comprises: a dual-axis motor (5), which is arranged in the cavity of the sample delivery body (2) and is connected to the controller for communication, wherein the two output shafts (51) of the dual-axis motor (5) extend from through holes on the top and bottom surfaces of the sample delivery body (2) to the outside of the sample delivery body (2), respectively, and the two output shafts (51) are sleeved with a second ring gear (511); two connecting tubes (52), which are sleeved on the two output shafts (51), and one end of the connecting tube (52) is fixedly connected to the motor housing of the dual-axis motor (5), a tube section of the connecting tube (52) is a rotating tube (53) structure, the outer side of the rotating tube (53) is sleeved with a third ring gear (531), and the inner side of the rotating tube (53) is sleeved with a fourth ring gear (532), and the fourth ring gear (532) is meshed with the second ring gear (511); Two rotating rings (3), the inner ring of each rotating ring (3) is sleeved with a first ring gear (32), the first ring gear (32) and the third ring gear (531) are meshed, and the outer peripheral surface of the rotating ring (3) is provided with a cleaning structure (31).

5. The undisturbed soil fixed volume automatic sampler according to claim 4, characterized in that: The cleaning structure (31) comprises a carrying ring and a plurality of groups of bristles, wherein the inner ring surface of the carrying ring is sleeved on the outer ring surface of the rotating ring (3), the plurality of groups of bristles are vertically arranged with respect to the ring surface of the carrying ring, and the plurality of groups of bristles are arranged in a circular array on the outer ring surface of the carrying ring, and one end of the plurality of groups of bristles abuts against the inner wall of the sampling tube (1).

6. The undisturbed soil fixed volume automatic sampler according to claim 4, characterized in that: It also includes two closing plates (4), both of which are circular plates and are located at the two ends of the dual-axis motor (5). The circular surfaces of the closing plates (4) are connected to the connecting pipe (52), and the center of the circle coincides with the central axis of the connecting pipe (52).

7. The undisturbed soil fixed volume automatic sampler according to claim 6, characterized in that: The height of the carrying ring is greater than the height of the rotating ring (3); the circular plate surface of the closing plate (4) close to the sample delivery body (2) is provided with a step structure (41) from its outer circumference toward the center of the circle; the circular end surface of the sample delivery body (2) close to the closing plate (4) is provided with a step structure (41) from its outer circumference toward the center of the circle; the step structure (41) on the sample delivery body (2) and the step structure (41) on the closing plate (4) are symmetrically arranged to form an accommodating space for accommodating bristles and the carrying ring.

8. The undisturbed soil fixed volume automatic sampler according to claim 6, characterized in that: An annular groove (33) is provided on the annular end surface of the rotating ring (3), and a positioning roller (42) is provided on the closing plate (4). The positioning roller (42) is connected to the closing plate (4) by rotating along its own axis, and one end of the positioning roller (42) is inserted into the annular groove (33).

9. The undisturbed soil fixed volume automatic sampler according to claim 1, characterized in that: The sampling tube (1) is equipped with a sampling tube drive assembly (7), and the sampling tube drive assembly (7) comprises: A guide plate (72) is located on one side of the sampling tube (1) and is arranged parallel to the sampling tube (1). A limiting sliding groove is provided on the plate surface of the guide plate (72) along the axial direction of the sampling tube (1). Support plates are provided at both ends of the guide plate (72); The ends of the lead screw (73) are rotatably connected to the surfaces of the two support plates, and the end of the lead screw (73) away from the sampling port of the sampling tube (1) is provided with a lead screw motor, and the lead screw motor is connected to the controller for communication; A threaded slider (71) is sleeved on the lead screw (73), one side of the threaded slider (71) is fixedly connected to the outer side of the sampling tube (1), and the other side is slidably connected in the limiting slide groove.

10. The undisturbed soil fixed volume automatic sampler according to claim 9, characterized in that: A fixing nail is provided at the bottom of the support plate near the sampling port of the sampling tube (1).

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