River sediment sampler
By designing a river bottom mud sampler with an articulated structure and a self-closing window mechanism, the problems of traditional samplers causing bottom mud disturbance and sample information loss are solved, and high-precision and low-disturbance bottom mud sampling is achieved to meet the needs of modern environmental monitoring.
Patent Information
- Application Number
- CN202520673254.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2035-04-10
AI Technical Summary
The traditional grab-type river bottom mud sampler will cause serious disturbance in the bottom mud structure during the sampling process, resulting in the loss of sample layering information, affecting the accuracy of the analysis results, and the operation is complex and the applicability is limited.
A river bottom mud sampler is designed, using a first grab and a second grab that is articulated with each other, and the opening and closing of the sampling space is controlled through the control rod, and a sampling window that can be opened and closed and self-closed and limiting mechanism is set on the grab to reduce bottom mud disturbance and provide on-site observation and selective sampling functions.
It effectively reduces structural disturbances during bottom mud sampling, maintains sample stratification information, improves collection accuracy and analysis accuracy, meets the needs of modern environmental monitoring, and improves the pertinence and scientificity of sampling.
Smart Images
Figure CN222882367U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a sampler, in particular to a river bottom mud sampler. Background Art
[0002] River sediment is an important environmental medium, rich in various material information, and plays an important role in indicating the health of river ecosystems. River sediment sampling is a key link in water environment monitoring and evaluation. Through physical, chemical and biological analysis of sediment samples, information such as pollutant distribution, accumulation history, and bioavailability can be obtained, providing a scientific basis for water environment protection, ecological restoration, and pollution source identification. Therefore, the development of efficient and accurate river sediment sampling equipment is of great practical significance for environmental monitoring, scientific research, and ecological protection.
[0003] At present, river sediment sampling technologies mainly include grab samplers, gravity samplers, column samplers and box samplers. Among them, grab samplers are widely used in river sediment sampling due to their simple structure, convenient operation and wide application range. Grab samplers mainly obtain surface sediment by mechanical grabbing. They are generally composed of two semicircular buckets, which close to form a sealed space to preserve samples after contacting the sediment. Other samplers such as gravity samplers rely on their own gravity to insert into the sediment to collect samples; column samplers can maintain the vertical profile structure of the sediment; box samplers are suitable for relatively complete surface sediment collection. These samplers have their own advantages in practical applications, but the operation is complicated, and most samplers require ship platform support, which limits their applicability in shallow water areas or areas with turbulent water flow.
[0004] Traditional grab bucket sediment samplers have significant defects in practical applications. When grab bucket samplers collect samples, they often cause serious disturbance of the sediment structure, resulting in loss of sample stratification information, making it difficult to maintain the original sedimentation state, and affecting the accuracy of the analysis results. In addition, the traditional grab bucket sampler has a closed structure. If field observation and selective sampling are to be carried out, the two grab buckets must be separated, which will affect their hierarchical distribution and thus the results of the stratification test. The above problems seriously restrict the quality and reliability of river sediment monitoring data, and it is difficult to meet the requirements of modern environmental monitoring and scientific research for high-precision, low-disturbance sediment samples. Utility Model Content
[0005] The purpose of the utility model is to provide a river sediment sampler, which can reduce structural disturbance during sediment sampling, maintain sample stratification information, improve collection accuracy and analysis accuracy, and meet modern environmental monitoring needs.
[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a river sediment sampler, comprising a first grab and a second grab hinged to each other, the first grab and the second grab can rotate relative to each other to form a sampling space, and a first control rod is fixed on the first grab, and a second control rod is fixed on the second grab, the first control rod and the second control rod cooperate with each other to control the opening and closing of the sampling space, a first sampling window is provided on the upper surface of the first grab, a first window cover that can be opened and closed is provided on the first sampling window, a first self-closing mechanism is provided between the first window cover and the first grab, which is used to keep the first window cover in a normally closed state, and a first limiting mechanism is also provided between the first window cover and the first grab, which is used to keep the first window cover in a normally open state, the bottom edges of the first grab and the second grab are provided with staggered bucket teeth, the bucket teeth are serrated and bent toward the sampling space, and counterweight mechanisms are detachably provided on the outer walls on both sides of the first grab and the second grab.
[0007] A second sampling window is provided on the upper surface of the second grab bucket, and a second window cover that can be opened and closed is provided on the second sampling window. A second self-closing mechanism is provided between the second window cover and the second grab bucket, which is used to keep the second window cover in a normally closed state. A second limiting mechanism is also provided between the second window cover and the second grab bucket, which is used to keep the second window cover in a normally open state.
[0008] Preferably, the first self-closing mechanism includes a first rotating shaft and a first torsion spring, two first fixed blocks are fixed at intervals on the upper surface of the first grab, two first hinge blocks are fixed at intervals on one end of the upper surface of the first window cover, the first rotating shaft is connected between the two first fixed blocks and the two first hinge blocks, and the first torsion spring is sleeved on the first rotating shaft and abuts against the upper surface of the first grab.
[0009] Preferably, the first limiting mechanism includes a first pulling block, a first hook and a first pulling ring, the first pulling block is fixed to the upper surface of the first window cover, the first pulling ring is fixed to the upper surface of the first grab and is located in the middle position between the two first fixed blocks, one end of the first hook is connected to the first pulling block, and the other end of the first hook is used to hook with the first pulling ring.
[0010] Preferably, the second self-closing mechanism includes a second rotating shaft and a second torsion spring, two second fixed blocks are fixed at intervals on the upper surface of the second grab, two second hinge blocks are fixed at intervals at one end of the upper surface of the second window cover, the second rotating shaft is connected between the two second fixed blocks and the two second hinge blocks, and the second torsion spring is sleeved on the second rotating shaft and abuts against the upper surface of the second grab.
[0011] Preferably, the second limiting mechanism includes a second pull block, a second hook and a second pull ring, the second pull block is fixed to the upper surface of the second window cover, the second pull ring is fixed to the upper surface of the second grab and is located in the middle position between the two second fixed blocks, one end of the second hook is connected to the second pull block, and the other end of the second hook is used to hook with the second pull ring.
[0012] Preferably, a plurality of first mounting blocks are fixed at intervals on the top edge of the first grab bucket, a plurality of second mounting blocks are fixed at intervals on the top edge of the second grab bucket, the first mounting blocks and the second mounting blocks are staggered, and an articulated shaft is connected between the first mounting blocks and the second mounting blocks.
[0013] Preferably, the counterweight mechanism comprises a counterweight block and fixing bolts, at least one threaded hole is provided on both side outer walls of the first grab bucket and the second grab bucket, and the counterweight block is detachably connected to the threaded hole via the fixing bolts.
[0014] Preferably, a plurality of water holes are provided on the side walls of the first grab bucket and the second grab bucket, and the water holes are connected to the sampling space.
[0015] Compared with the prior art, the advantages of the utility model are: the device can realize the opening and closing of the sampling space through the operation of the first control lever and the second control lever, and is designed with an upper surface sampling window, equipped with a self-closing mechanism and a limit mechanism, so that the operator can conduct on-site observation and selective sampling without destroying the overall sample, which greatly improves the pertinence and scientificity of the sampling; the design of the staggered serrated bucket teeth on the bottom edge bending toward the sampling space can effectively reduce the disturbance of the bottom mud and maintain the original hierarchical structure of the sample, while enhancing the ability to grasp the bottom mud and prevent the loss of fine particles; the detachable counterweight mechanism allows the operator to adjust the weight of the sampler according to different water environments, bottom mud types and water flow conditions to ensure that the sampling process is stable and controllable.
[0016] This design not only solves the problems of large sample disturbance, serious leakage, and blind operation of traditional grab samplers, but also significantly improves the accuracy, integrity and representativeness of river sediment sampling, providing more reliable support for water environment monitoring and evaluation. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0018] Figure 1It is a three-dimensional structural schematic diagram of the utility model;
[0019] Figure 2 This is a schematic diagram of the state when the sampling space is closed in the utility model;
[0020] Figure 3 This is a schematic diagram of the state when the sampling space in the utility model is opened;
[0021] Figure 4 It is a three-dimensional structural schematic diagram of the first grab bucket in the utility model;
[0022] Figure 5 It is a three-dimensional structural diagram of the second grab bucket, the second self-closing mechanism and the second limiting mechanism in the present utility model when they cooperate with each other;
[0023] In the figure, 1, the first grab bucket; 2, the second grab bucket; 3, the sampling space; 4, the first control rod; 5, the second control rod; 6, the first sampling window; 7, the first window cover; 8, the first self-closing mechanism; 9, the first limiting mechanism; 10, the bucket tooth; 11, the counterweight mechanism; 12, the second sampling window; 13, the second window cover; 14, the second self-closing mechanism; 15, the second limiting mechanism; 16, the first rotating shaft; 17, the first torsion spring; 18, the first Fixed block; 19, first hinge block; 20, first pull block; 21, first hook; 22, first pull ring; 24, second rotating shaft; 25, second torsion spring; 26, second fixed block; 27, second hinge block; 28, second pull block; 29, second hook; 30, second pull ring; 32, first mounting block; 33, second mounting block; 34, hinge shaft; 35, counterweight block; 36, fixing bolt; 37, threaded hole; 38, water hole. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0025] Embodiment 1: Figure 1-Figure 5As shown, a river sediment sampler comprises a first grab bucket 1 and a second grab bucket 2 which are hinged to each other, the first grab bucket 1 and the second grab bucket 2 can rotate relative to each other to form a sampling space 3, and a first control rod 4 is fixed on the first grab bucket 1, and a second control rod 5 is fixed on the second grab bucket 2, the first control rod 4 and the second control rod 5 cooperate with each other to control the opening and closing of the sampling space 3, a first sampling window 6 is provided on the upper surface of the first grab bucket 1, a first window cover 7 which can be opened and closed is provided on the first sampling window 6, a first self-closing mechanism 8 is provided between the first window cover 7 and the first grab bucket 1, which is used to keep the first window cover 7 in a normally closed state, a first limiting mechanism 9 is also provided between the first window cover 7 and the first grab bucket 1, which is used to keep the first window cover 7 in a normally open state, the bottom edges of the first grab bucket 1 and the second grab bucket 2 are provided with staggered bucket teeth 10, the bucket teeth 10 are serrated and bent toward the sampling space 3, and counterweight mechanisms 11 are detachably provided on the outer walls on both sides of the first grab bucket 1 and the second grab bucket 2.
[0026] When using the river sediment sampler for sediment sampling, firstly, the first grab 1 and the second grab 2 need to be in an open state, and the sampling space 3 is kept fully expanded by controlling the first control rod 4 and the second control rod 5. Then, according to the depth of the sampling water area and the bottom characteristics, appropriate counterweight devices are installed on the outer walls of both sides of the grab to ensure that the sampler can sink smoothly and stably contact the sediment. Then, the operator slowly puts the sampler into the water along the rope or rod until it contacts the river bottom. At this time, gently shake the control rod to make the bucket teeth 10 fully insert into the surface of the sediment. Then, by coordinating the operation of the two control rods, the two grabs are relatively rotated and closed, and the serrated and inwardly curved bucket teeth 10 will interlock and bite, effectively closing the sampling space 3 and cutting the sediment.
[0027] When the sampler is lifted to the water surface, the first window cover 7 on the upper surface of the first grab bucket 1 can be opened (the window is kept open by the first limiting mechanism 9) to conduct on-site observation and selective sampling of the collected sediment samples. After completion, the window cover is locked by the first self-closing mechanism 8 to ensure that the remaining sample will not be lost. Finally, the entire sample is transferred to the sample container for subsequent processing and analysis.
[0028] Embodiment 2: Figure 1-Figure 5 As shown, different from the first embodiment, a second sampling window 12 is provided on the upper surface of the second grab 2, and a second window cover 13 that can be opened and closed is provided on the second sampling window 12. A second self-closing mechanism 14 is provided between the second window cover 13 and the second grab 2, which is used to keep the second window cover 13 in a normally closed state. A second limiting mechanism 15 is also provided between the second window cover 13 and the second grab 2, which is used to keep the second window cover 13 in a normally open state.
[0029] In the above structure, the second sampling window 12 arranged on the upper surface of the second grab 2 is an important supplement to the first sampling window 6, forming a complete double-window sampling structure. The second sampling window 12 is equipped with an openable and closable window cover, which is reliably maintained in a normally closed state through a second self-closing mechanism 14. The second self-closing mechanism 14 can apply continuous and stable pressure to the window cover during the closing, lifting and transportation of the sampler, ensuring that the bottom mud sample will not leak from the window, effectively ensuring the integrity and representativeness of the sample. At the same time, the design of the second limiting mechanism 15 enables the window cover to remain normally open when needed, and the operator does not need to continuously hold the window cover with his hands, freeing up both hands for delicate sampling operations.
[0030] This design is particularly suitable for observing and selectively sampling the bottom mud captured in the second grab bucket 2, especially when the bottom mud presents a layered structure or needs to be studied in a specific depth area. The second sampling window 12 system can provide additional observation and sampling angles, making up for the visual limitations and operational inconveniences that may be caused by relying solely on the first sampling window 6, and significantly improving the accuracy, comprehensiveness and scientificity of the sampling.
[0031] In this embodiment, the first self-closing mechanism 8 includes a first rotating shaft 16 and a first torsion spring 17, two first fixed blocks 18 are fixed at intervals on the upper surface of the first grab 1, and two first hinge blocks 19 are fixed at intervals at one end of the upper surface of the first window cover 7. The first rotating shaft 16 is connected between the two first fixed blocks 18 and the two first hinge blocks 19, and the first torsion spring 17 is sleeved on the first rotating shaft 16 and abuts against the upper surface of the first grab 1.
[0032] The first self-closing mechanism 8 adopts a rotating shaft-torsion spring structural design to form a stable hinged support. The first torsion spring 17 is sleeved on the first rotating shaft 16 and abuts against the upper surface of the first grab 1. The elastic potential energy of the torsion spring is used to generate continuous pressure, so that the first window cover 7 always remains tightly closed in a natural state. The advantage of this design is that the structure is simple and reliable, and the window cover can be kept in a normally closed state without a complicated locking device. At the same time, the elastic force of the torsion spring is moderate, which can ensure that the window cover fits tightly to prevent sample leakage, and will not cause excessive resistance to affect the sampling operation.
[0033] In this embodiment, the first limiting mechanism 9 includes a first pull block 20, a first hook 21 and a first pull ring 22. The first pull block 20 is fixed on the upper surface of the first window cover 7, and the first pull ring 22 is fixed on the upper surface of the first grab 1 and is located in the middle position of the two first fixed blocks 18. One end of the first hook 21 is connected to the first pull block 20, and the other end of the first hook 21 is used to hook with the first pull ring 22.
[0034] The first limiting mechanism 9 is simple and practical in design. When the first window cover 7 needs to be kept in an open state, the operator only needs to lift the first window cover 7, and then hook the first pull ring 22 with the first hook 21, and the first window cover 7 can be stably kept in the open position, so that the operator can free both hands to perform sampling. The first limiting mechanism 9 and the first self-closing mechanism 8 form a complementary relationship. The first self-closing mechanism 8 ensures that the first window cover 7 is always closed, while the first limiting mechanism 9 ensures that the first window cover 7 can be kept always open when needed. This mechanical structure is not easy to damage and is suitable for outdoor environments. The positions of various components are reasonably designed, the operation is simple and intuitive, the overall structure is firm and reliable, and it is not easy to get unhooked even in a bumpy environment, which greatly improves the efficiency and accuracy of on-site sampling.
[0035] In this embodiment, the second self-closing mechanism 14 includes a second rotating shaft 24 and a second torsion spring 25, two second fixed blocks 26 are fixed at intervals on the upper surface of the second grab 2, and two second hinge blocks 27 are fixed at intervals at one end of the upper surface of the second window cover 13. The second rotating shaft 24 is connected between the two second fixed blocks 26 and the two second hinge blocks 27, and the second torsion spring 25 is sleeved on the second rotating shaft 24 and abuts against the upper surface of the second grab 2.
[0036] In the above structure, the second self-closing mechanism 14 adopts the same rotating shaft-torsion spring structure design as the first self-closing mechanism 8. Two second fixed blocks 26 are fixed at intervals on the upper surface of the second grab 2, and two second hinged blocks 27 are fixed at intervals on one end of the upper surface of the second window cover 13. These components are connected by the second rotating shaft 24 to form an articulated support. At the same time, the second torsion spring 25 is sleeved on the rotating shaft and abuts against the upper surface of the second grab 2. This structure uses the elastic potential energy of the torsion spring to generate continuous pressure, so that the second window cover 13 always remains tightly closed in a natural state, effectively preventing the sediment sample from leaking from the window. The symmetrical design of the double fixed blocks and the double hinged blocks enhances the overall structural stability and prevents the window cover from being offset or deformed during use.
[0037] This mechanical clamping structure is simple and reliable, not affected by the water environment, has strong corrosion resistance, and is easy to maintain. It can maintain a good working condition even under long-term field working conditions, and provides reliable guarantee for the complete preservation of the bottom mud sample in the second grab bucket 2. Together with the first self-closing mechanism 8, it constitutes a complete double-window protection system.
[0038] In this embodiment, the second limiting mechanism 15 includes a second pull block 28, a second hook 29 and a second pull ring 30. The second pull block 28 is fixed to the upper surface of the second window cover 13. The second pull ring 30 is fixed to the upper surface of the second grab 2 and is located in the middle position of the two second fixed blocks 26. One end of the second hook 29 is connected to the second pull block 28, and the other end of the second hook 29 is used to hook with the second pull ring 30.
[0039] The second limiting mechanism 15 is composed of three key components: a second pull block 28, a second hook 29 and a second pull ring 30, forming a complete window cover positioning system. The second pull block 28 is firmly fixed on the upper surface of the second window cover 13, and the second pull ring 30 is fixed on the upper surface of the second grab 2 and located in the middle of the two second fixing blocks 26. One end of the second hook 29 is connected to the second pull block 28, and the other end can be flexibly connected to the second pull ring 30.
[0040] When it is necessary to keep the second window cover 13 open, the operator only needs to lift the second window cover 13 and use the second hook 29 to hook the second pull ring 30 to keep the second window cover 13 stably in the open position, thereby freeing both hands to perform delicate sampling operations. This design complements the second self-closing mechanism 14. The second self-closing mechanism 14 ensures that the second window cover 13 remains closed during sampling and transportation to prevent sample loss, while the second limiting mechanism 15 provides a reliable opening and fixing function when sampling is required. The entire structural design is simple and practical, the positions of the components are reasonably arranged, the operation is intuitive and convenient, and it has high mechanical strength. It can maintain a stable working state even in complex environments in the wild, effectively improving the practicality and operating efficiency of the sampling window of the second grab 2.
[0041] In this embodiment, a plurality of first mounting blocks 32 are fixed at intervals on the top edge of the first grab bucket 1, and a plurality of second mounting blocks 33 are fixed at intervals on the top edge of the second grab bucket 2. The first mounting blocks 32 and the second mounting blocks 33 are staggered, and an articulated shaft 34 is connected between the first mounting blocks 32 and the second mounting blocks 33.
[0042] In the above structure, a plurality of first mounting blocks 32 are fixed at intervals on the top edge of the first grab 1, and a plurality of second mounting blocks 33 are fixed at intervals on the top edge of the second grab 2. The two groups of mounting blocks are staggered and connected by an articulated shaft 34. This structural design enables the two grabs to rotate smoothly around the articulated shaft 34 to form a reliable mechanical connection.
[0043] The staggered mounting blocks increase the number of hinge points, significantly improving the stability and load-bearing capacity of the overall structure, allowing the sampler to withstand greater sediment weight and water flow impact. At the same time, the multi-point hinge design also ensures that the two grab buckets remain precisely aligned during the opening and closing process to avoid leakage problems caused by misalignment. The hinge shaft 34 runs through all the mounting blocks to form a solid rotation axis, making the opening and closing of the grab bucket smoother and more uniform. This hinge structure is simple and reliable, easy to maintain, and has strong durability. It can maintain good working condition even in long-term use and harsh environments.
[0044] Embodiment 3: Figure 1-Figure 5As shown, different from the second embodiment, the counterweight mechanism 11 includes a counterweight block 35 and a fixing bolt 36, and at least one threaded hole 37 is opened on the outer walls of both sides of the first grab bucket 1 and the second grab bucket 2, and the counterweight block 35 is detachably connected to the threaded hole 37 by the fixing bolt 36.
[0045] This structural design makes the sampler extremely adaptable. The operator can adjust the number, position and weight of the counterweights 35 according to different water environments and bottom mud types, so as to control the sinking speed and stability of the sampler. For example, in shallow water areas or soft bottom mud environments, the number of counterweights 35 can be reduced to avoid excessive sinking; while in areas with turbulent water flow or hard bottom mud environments, the counterweights 35 can be increased to provide sufficient downward force.
[0046] The threaded connection ensures that the counterweight 35 is firmly installed and will not loosen or fall off during the sampling process. At the same time, it is convenient for quick disassembly and adjustment on site. The design of multiple threaded holes 37 further enhances the flexibility of the counterweight position. The center of gravity position can be adjusted as needed to optimize the balance and stability of the sampler. This detachable counterweight design also facilitates equipment transportation and storage, greatly improving the practicality and applicability of the sampler.
[0047] In this embodiment, a plurality of water holes 38 are provided on the side walls of the first grab bucket 1 and the second grab bucket 2 , and the water holes 38 are connected to the sampling space 3 .
[0048] When the sampler sinks, the water hole 38 allows water to flow freely through the grab, reducing water resistance and enabling the sampler to reach the target position more quickly and smoothly. After contacting the bottom mud, when the grab is closed, the water hole 38 can discharge excess water, reducing the weight of the sampler and facilitating lifting operations. At the same time, this design can also gradually discharge overlying water while retaining the bottom mud sample, avoiding excessive dilution of the sample and improving the concentration and representativeness of the sample.
[0049] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A river sediment sampler, comprising a first grab and a second grab that are hinged to each other, the first grab and the second grab can rotate relative to each other to form a sampling space, and a first control rod is fixed on the first grab, and a second control rod is fixed on the second grab, the first control rod and the second control rod cooperate with each other to control the opening and closing of the sampling space, characterized in that: A first sampling window is provided on the upper surface of the first grab bucket, and a first window cover that can be opened and closed is provided on the first sampling window. A first self-closing mechanism is provided between the first window cover and the first grab bucket, which is used to keep the first window cover in a normally closed state. A first limiting mechanism is also provided between the first window cover and the first grab bucket, which is used to keep the first window cover in a normally open state. The bottom edges of the first grab bucket and the second grab bucket are provided with staggered bucket teeth, which are serrated and bent toward the sampling space. Counterweight mechanisms are detachably provided on the outer walls on both sides of the first grab bucket and the second grab bucket.
2. A river sediment sampler according to claim 1, characterized in that: A second sampling window is provided on the upper surface of the second grab bucket, and a second window cover that can be opened and closed is provided on the second sampling window. A second self-closing mechanism is provided between the second window cover and the second grab bucket, which is used to keep the second window cover in a normally closed state. A second limiting mechanism is also provided between the second window cover and the second grab bucket, which is used to keep the second window cover in a normally open state.
3. A river sediment sampler according to claim 1, characterized in that: The first self-closing mechanism includes a first rotating shaft and a first torsion spring. Two first fixed blocks are fixed at intervals on the upper surface of the first grab bucket. Two first hinge blocks are fixed at intervals at one end of the upper surface of the first window cover. The first rotating shaft is connected between the two first fixed blocks and the two first hinge blocks. The first torsion spring is sleeved on the first rotating shaft and abuts against the upper surface of the first grab bucket.
4. A river sediment sampler according to claim 3, characterized in that: The first limiting mechanism includes a first pulling block, a first hook and a first pulling ring. The first pulling block is fixed to the upper surface of the first window cover. The first pulling ring is fixed to the upper surface of the first grab and is located in the middle of the two first fixed blocks. One end of the first hook is connected to the first pulling block, and the other end of the first hook is used to hook with the first pulling ring.
5. A river sediment sampler according to claim 2, characterized in that: The second self-closing mechanism includes a second rotating shaft and a second torsion spring, two second fixed blocks are fixed at intervals on the upper surface of the second grab, two second hinge blocks are fixed at intervals at one end of the upper surface of the second window cover, the second rotating shaft is connected between the two second fixed blocks and the two second hinge blocks, and the second torsion spring is sleeved on the second rotating shaft and abuts against the upper surface of the second grab.
6. A river sediment sampler according to claim 5, characterized in that: The second limiting mechanism includes a second pulling block, a second hook and a second pulling ring. The second pulling block is fixed to the upper surface of the second window cover. The second pulling ring is fixed to the upper surface of the second grab and is located in the middle of the two second fixed blocks. One end of the second hook is connected to the second pulling block, and the other end of the second hook is used to hook with the second pulling ring.
7. A river sediment sampler according to claim 1, characterized in that: A plurality of first mounting blocks are fixed at intervals on the top edge of the first grab bucket, a plurality of second mounting blocks are fixed at intervals on the top edge of the second grab bucket, the first mounting blocks and the second mounting blocks are staggered, and a hinge shaft is connected between the first mounting blocks and the second mounting blocks.
8. A river sediment sampler according to claim 1, characterized in that: The counterweight mechanism includes a counterweight block and fixing bolts. At least one threaded hole is provided on both side outer walls of the first grab bucket and the second grab bucket. The counterweight block is detachably connected to the threaded hole via the fixing bolts.
9. A river sediment sampler according to claim 1, characterized in that: A plurality of water holes are provided on the side walls of the first grab bucket and the second grab bucket, and the water holes are connected to the sampling space.