Water area sampling device and method for water quality pollution detection
By designing pumping mechanisms and switching units adapted to different water depths, the problems of immersion difficulties, silt interference, and rope entanglement in sampling devices in shallow water environments were solved, achieving efficient and accurate sampling and easy operation in complex waters.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- LINYI MUNICIPAL ECOLOGICAL ENVIRONMENT BUREAU LINSHU COUNTY BRANCH
- Filing Date
- 2026-04-30
- Publication Date
- 2026-07-21
AI Technical Summary
Existing water sampling devices suffer from several problems: difficulty in immersion triggering in shallow water environments, easy stirring up of silt leading to sample distortion, and entanglement of multiple ropes causing operational inconvenience.
A sampling device was designed, which includes a water storage tank, a pumping mechanism and a switching unit. The pumping mechanism is designed to adapt to waters of different depths, the switching unit reduces silt interference, and a combination of a sleeve and a traction cable is used to prevent the rope from getting tangled.
It enables successful sampling in environments with different water depths, ensuring sample representativeness and ease of operation, and improving the accuracy and simplicity of shallow water sampling data.
Smart Images
Figure CN122430102A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geographic surveying and sampling equipment technology, and in particular to a water sampling device and method for water pollution detection. Background Technology
[0002] Water sampling devices are the core front-end equipment for water pollution detection. Their function is to obtain water samples in a standardized and objective manner, ensuring the accuracy and traceability of subsequent physicochemical and biological analysis data. They can also achieve spatial stratified quantitative sampling, allowing staff to sample at different depths of the water body through the operation of the device. This avoids sample deviations caused by water thermal stratification, density flow, or uneven pollutant settling, ensuring that the obtained water samples have true spatial representativeness.
[0003] Traditional sampling devices are widely used in geographic surveying, but due to limitations in their structure and working principle, they often have some unavoidable problems. Existing equipment has significant shortcomings when sampling in extremely shallow waters. Conventional samplers are often large and heavy, making it difficult to fully submerge in very shallow areas. This results in ineffective sampling actions, directly limiting the normal use of the equipment in special environments such as shallow waters, nearshore areas, and during dry seasons, greatly restricting its applicability. Simultaneously, shallow water areas are often rich in bottom silt, and existing equipment often lacks effective slow-suction mechanisms. The suction action often causes violent water flow disturbances, stirring up bottom sediments and mixing them into the sample. This leads to the water sample losing its representativeness and failing to accurately reflect the water quality of that layer, directly affecting the accuracy of subsequent testing results. Furthermore, there is room for optimization in the operation of existing equipment. Traditional equipment often uses a multi-rope parallel traction and triggering design, which is prone to entanglement during lowering and retrieval, causing the equipment to jam or malfunction, increasing the difficulty of operation. Overall, existing equipment needs improvement in terms of sampling accuracy, environmental adaptability, and ease of operation when facing complex and ever-changing shallow water environments. Summary of the Invention
[0004] In view of the problems of existing technology, such as difficulty in immersion triggering in shallow water environments, easy stirring of silt leading to sample distortion, and easy entanglement of multiple ropes causing inconvenience in operation, a water sampling device for water pollution detection is proposed.
[0005] Its purpose is to enable the sampling device to adapt to different water environments of varying depths, avoid interference from silt in shallow water sampling, be easy to operate, and prevent entanglement.
[0006] The technical solution of the present invention is a water sampling device for water pollution detection, including a water storage tank, a piston disposed inside the water storage tank, a pull rod disposed on the top of the piston, and a pumping mechanism disposed on the top of the pull rod. The pumping mechanism includes handles symmetrically arranged at the top of the pull rod, a retraction hole at the top of the pull rod, a traction cable located in the middle and upper inner wall of the retraction hole, a sleeve sleeved on the outside of the traction cable, limiting pins symmetrically arranged at the bottom of the retraction hole, the bottom end of the traction cable being fixedly connected to the two limiting pins respectively, a return spring located in the middle of the two limiting pins, the two ends of the return spring being fixedly connected to the two limiting pins respectively, an annular groove on the inner wall of the water tank near the limiting pins, a tension spring sleeved on the outside of the pull rod, the two ends of the tension spring being fixedly connected to the piston and the water tank respectively, a baffle on the inner wall of the bottom of the water tank, a hook at the bottom of the baffle, a curved groove on the outer wall of the bottom of the water tank, and a switching unit located at the top of the water tank.
[0007] Furthermore, the water tank has an inlet at the bottom and several vents arranged in a ring array at the top.
[0008] Furthermore, a connecting plate is provided on the side of the baffle away from the hook, and the inner wall of the bottom of the water tank away from the hook is rotatably connected to the connecting plate.
[0009] Furthermore, the bottom end of the traction cable is symmetrically provided with two support cables, and the bottom ends of the two support cables are respectively fixedly connected to corresponding limiting pins.
[0010] Furthermore, a positioning hole is provided at the bottom end of the limiting pin, and a support shaft is provided at the bottom of the inner wall of the receiving hole, with the outer wall of the support shaft rotatably connected to the inner wall of the positioning hole.
[0011] Furthermore, the switching unit includes a fixed sleeve disposed on the top of the water storage tank, a lifting plate disposed on the outer wall of the fixed sleeve, telescopic holes symmetrically opened on the water storage tank near the top of the annular groove, a damping block disposed at the bottom of the telescopic hole, a pressure block disposed on the top of the telescopic hole, a counterweight block symmetrically disposed on the outside of the water storage tank, an outer shell disposed on the water storage tank at the midpoint between the two counterweight blocks, a connecting pipe disposed inside the outer shell, a plurality of linear arrays of connection ports disposed on the side of the connecting pipe away from the water storage tank, and a plurality of linear arrays of suction ports disposed on the side of the outer shell away from the water storage tank.
[0012] Furthermore, the top of the outer shell is provided with a receiving cavity, the bottom of which is connected to the interior of the water storage tank. The outer wall of the fixing sleeve is provided with threads, and the top of the lifting plate is provided with a threaded hole that extends to the bottom. The threaded hole is threadedly connected to the outer wall of the fixing sleeve.
[0013] Furthermore, a driving inclined surface is provided at the bottom of the pressure block, and a passive inclined surface is provided on the side of the damping block away from the pull rod, with the driving inclined surface and the passive inclined surface slidably connected.
[0014] Another object of the present invention is to provide a water sampling method for water pollution detection, the purpose of which is to perform water sampling in conjunction with a sampling device.
[0015] To achieve the above objectives, the present invention provides the following technical solution: a water sampling method for water pollution detection, comprising the following steps: First, the water storage tank is placed into the water area, and different sampling modes are selected according to the water depth of the sampling area; Then, during deep water sampling, the traction cable is pulled to retract the limit pin, which causes the tension spring to drive the piston to move upward. The upward movement of the piston creates negative pressure inside the water storage tank, drawing water samples from the outside into the water storage tank. When the depth of the sampling area is less than the height of the water storage tank, the water intake port is positioned downward and slowly draws water through the action of the switching unit. Finally, after the water tank has drawn in enough water, it is lifted out of the water and retrieved using a sleeve.
[0016] Furthermore, after the water tank is retrieved, water samples are taken from inside the tank, repackaged, and sent for testing.
[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting up a pumping mechanism, the device can adapt to sampling needs in waters of varying depths, thereby increasing its applicability. When facing waters of sufficient depth, the pumping mechanism can trigger a water suction action to complete sample collection in deep water areas. When facing shallow waters with insufficient depth, the pumping mechanism can work with other modules to adjust the water suction rhythm, ensuring that water samples can still be successfully obtained even under conditions of limited water level. This operational method, which takes into account both deep and shallow water environments, breaks through the shortcomings of traditional equipment that is limited to specific water depths. It enables the equipment to perform sampling functions in various complex water environments such as rivers and lakes, effectively expanding the equipment's operational range and application scenarios.
[0018] 2. By setting up a switching unit, the device can reduce sampling inaccuracies caused by factors such as silt when sampling in shallow water. When operating in shallow water areas, silt at the bottom of the water body is easily suspended by water flow disturbance, thus mixing into the collected water sample and interfering with the test results. The switching unit can change the water intake mode of the device, making the water intake process gentler and avoiding the formation of a strong suction effect in local areas, thereby preventing the silt at the bottom from being rolled up. This design ensures that the collected water sample can truly reflect the water quality of the water layer, eliminates the interference of impurities, improves the data accuracy and reliability of the shallow water sampling process, and provides a pure sample basis for subsequent water pollution detection.
[0019] 3. By incorporating a traction cable and sleeve, unlike the traditional structure where two independent ropes are used for traction and triggering, this design solves the problem of ropes easily tangling together, making operation more convenient. Traditional dual-rope structures are prone to entanglement during lowering and lifting due to water flow impact or differences in operator movements, leading to equipment malfunction or even jamming. This equipment uses a combination of sleeve and internal traction cable, integrating lowering control and triggering control on the same axis. These two controls are independent and do not interfere with each other, eliminating the risk of entanglement associated with multiple parallel lines. Operators can easily complete the lifting, lowering, and sampling commands with simple operations, simplifying the workflow and reducing operational difficulty. Attached Figure Description
[0020] Figure 1 This is a three-dimensional structural diagram of the sampling device of the present invention; Figure 2 This is a schematic diagram of the internal structure of the water storage tank of the sampling device of the present invention; Figure 3 This is a schematic diagram of the connection between the hook and the groove in the sampling device of the present invention; Figure 4 This is a schematic diagram showing the connection between the damping block and the pressure block in the sampling device of the present invention; Figure 5 This is a schematic diagram showing the connection between the receiving / discharging hole and the limiting pin of the sampling device of the present invention; Figure 6 This is a schematic diagram showing the connection between the traction cable and the sleeve of the sampling device of the present invention; Figure 7 This is a schematic diagram of the internal structure of the pull rod of the sampling device of the present invention; Figure 8 This is a schematic diagram of the outer shell structure of the sampling device of the present invention; Figure 9 This is a schematic diagram showing the connection between the connecting tube and the outer shell of the sampling device of the present invention; Figure 10 This is a schematic diagram of the connecting pipe structure of the sampling device of the present invention; Figure 11 This is a schematic diagram showing the connection between the hook and the baffle of the sampling device of the present invention.
[0021] In the picture: 1. Water storage tank; 2. Piston; 3. Pull rod; 4. Pumping mechanism; 41. Handle; 42. Retracting hole; 43. Traction rope; 44. Sleeve; 45. Limiting pin; 46. Return spring; 47. Ring groove; 48. Tension spring; 49. Baffle; 410. Hook; 411. Bend; 412. Fixing sleeve; 413. Lifting plate; 414. Telescopic hole; 415. Damping block; 416. Pressure block; 417. Counterweight; 418. Outer shell; 419. Connecting pipe; 420. Connecting interface; 421. Water suction port. Detailed Implementation
[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0023] Example 1, referring to Figures 1-11 This invention provides a first embodiment of a water sampling device for water pollution detection, comprising a water storage tank 1, a piston 2 slidably connected inside the water storage tank 1, a pull rod 3 fixedly connected to the top of the piston 2, and a pumping mechanism 4 mounted on the top of the pull rod 3. The pumping mechanism 4 includes a handle 41 symmetrically fixedly connected to the top of the pull rod 3, a retraction hole 42 at the top of the pull rod 3, a traction cable 43 slidably connected to the middle and upper inner walls of the retraction hole 42, a sleeve 44 sleeved on the outside of the traction cable 43, and limiting pins 45 symmetrically rotatably connected to the bottom of the retraction hole 42. The bottom end is fixedly connected to two limit pins 45 respectively, and a return spring 46 is fixedly connected to the middle of the two limit pins 45. The two ends of the return spring 46 are fixedly connected to the two limit pins 45 respectively. An annular groove 47 is opened on the inner wall of the water tank 1 near the limit pins 45. A tension spring 48 is sleeved on the outside of the pull rod 3. The two ends of the tension spring 48 are fixedly connected to the piston 2 and the water tank 1 respectively. A baffle 49 is rotatably connected to the inner wall of the bottom of the water tank 1. A hook 410 is rotatably connected to the bottom of the baffle 49. A curved groove 411 is opened on the outer wall of the bottom of the water tank 1. And a switching unit is assembled on the top of the water tank 1.
[0024] Specifically, by gripping handle 41 and pressing down pull rod 3, pull rod 3 drives piston 2 to move downward. The downward movement of piston 2 causes tension spring 48 to store force. Simultaneously, pull rod 3 moves downward, causing limit pin 45 to move as well. Since the two limit pins 45 maintain an outward expanding trend under the action of return spring 46, after the limit pins 45 move downward a certain distance, their tops will engage with annular groove 47. At this time, limit pins 45 lock pull rod 3, preventing it from moving upward. When sampling deep water, grip the top of sleeve 44 and then put water tank 1 into the water. After water tank 1 enters the water, water flows into its interior through the vent, expelling the internal air. At this time, the buoyancy of water tank 1 decreases, causing it to sink. The operator controls the sinking depth of water tank 1 through sleeve 44. After water tank 1 reaches the appropriate depth, pull up the top of traction cable 43, causing it to sink relative to sleeve 44. As the traction cable 43 moves upward, it simultaneously pulls the two limiting pins 45 through the bottom support cable, causing the limiting pins 45 to retract into the receiving and discharging hole 42. When the limiting pins 45 retract into the receiving and discharging hole 42, the locking of the pull rod 3 is released. At this time, the tension spring 48 pulls the piston 2 upward. As the piston 2 moves upward, it creates a negative pressure inside the water storage tank 1. At this time, the external water flow lifts the baffle 49 through the water inlet, causing it to rotate. At this time, the baffle 49 releases its obstruction of the water inlet, thus entering the interior of the water storage tank 1. Then, the water storage tank 1 is lifted out for blowing. At this time, the water flow inside the water storage tank 1 pushes the baffle 49 downward under the action of gravity. Since the bottom of the baffle 49 is in contact with the inner wall of the water storage tank 1, it closes the outlet under the push of the water flow, preventing the water sample from flowing out. After the water storage tank 1 is retracted, the baffle 49 is pushed upward, allowing the water sample inside the water storage tank 1 to flow out.
[0025] Reference Figure 1 and Figure 2 The bottom of the water storage tank 1 has a water inlet, and the top of the water storage tank 1 has several exhaust ports arranged in a ring array.
[0026] Specifically, external water flows into the water storage tank 1 through the inlet. The inlet cooperates with the baffle 49 so that the water cannot flow out in reverse without human intervention.
[0027] Reference Figure 2 A connecting plate is provided on the side of the baffle 49 away from the hook 410, and the bottom inner wall of the water tank 1 away from the hook 410 is rotatably connected to the connecting plate.
[0028] Specifically, the baffle 49 is connected to the water storage tank 1 via a connecting plate. When the bottom of the baffle 49 is subjected to force, it will rotate upwards, and after the baffle 49 rotates downwards until its bottom surface is in contact with the water storage tank 1, it will stop rotating.
[0029] Reference Figures 5-7 Two symmetrical support cables are provided at the bottom end of the traction cable 43, and the bottom ends of the two support cables are fixedly connected to the corresponding limiting pins 45 respectively.
[0030] Specifically, the traction cable 43 is connected to the corresponding limiting pin 45 via a branch cable. When the traction cable 43 moves upward, it will drive the tops of the two limiting pins 45 to move closer to each other.
[0031] Reference Figure 5 and Figure 7 The bottom end of the limiting pin 45 is provided with a positioning hole, and the bottom of the inner wall of the receiving hole 42 is provided with a support shaft, and the outer wall of the support shaft is rotatably connected to the inner wall of the positioning hole.
[0032] Specifically, the limiting pin 45 is constrained by the positioning hole and the support shaft, so it can only rotate around the support shaft after being subjected to force.
[0033] Example 2, refer to Figures 1-11 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the switching unit includes a fixed sleeve 412 fixedly connected to the top of the water storage tank 1, a lifting plate 413 threadedly connected to the outer wall of the fixed sleeve 412, a telescopic hole 414 symmetrically opened at the top of the water storage tank 1 near the annular groove 47, a damping block 415 slidably connected to the bottom of the telescopic hole 414, a pressure block 416 slidably connected to the top of the telescopic hole 414, a counterweight block 417 symmetrically fixedly connected to the outside of the water storage tank 1, a shell 418 fixedly connected to the water storage tank 1 at the middle of the two counterweight blocks 417, a connecting pipe 419 rotatably connected inside the shell 418, a plurality of linear arrays of connection ports 420 opened on the side of the connecting pipe 419 away from the water storage tank 1, and a plurality of linear arrays of suction ports 421 opened on the side of the shell 418 away from the water storage tank 1.
[0034] Specifically, when the sampling water area is shallow and insufficient to submerge the water storage tank 1, the hook 410 is rotated to engage with the bend 411, thereby fixing the baffle 49. Then, the connecting pipe 419 is rotated, causing the interface 420 to rotate and align with the suction port 421. The lifting plate 413 is then rotated, moving downwards along the axis of the fixing sleeve 412. Simultaneously, the lifting plate 413 pushes the pressure block 416 downwards, compressing the damping block 415 and causing it to press against the outer wall of the pull rod 3. At this point, the water storage tank is opened. After tank 1 is placed into the water, the side of tank 1 connected to counterweight 417 will be in a downward position, so that the suction port 421 will also be in a downward position. Then, the piston 2 is triggered by the traction cable 43 to draw water. During this process, the pull rod 3 moves slowly under the friction of the damping block 415, which slows down the entire pumping process. Under the action of negative pressure, the external water flows through the suction port 421 and the interface 420 in sequence and enters the interior of the connecting pipe 419. Then, it enters the interior of tank 1 through the receiving cavity of the outer shell 418. By slowly drawing water, the external water flow is prevented from entering too quickly and stirring up the silt and bringing it into tank 1.
[0035] Reference Figures 4-9 The top of the outer shell 418 is provided with a receiving cavity, the bottom of which is connected to the interior of the water storage tank 1. The outer wall of the fixing sleeve 412 is provided with threads, and the top of the lifting plate 413 is provided with a threaded hole that extends to the bottom. The threaded hole is threadedly connected to the outer wall of the fixing sleeve 412.
[0036] Specifically, after the water flows into the connecting pipe 419, it enters the receiving cavity through the bottom of the connecting pipe 419 and then flows into the water storage tank 1.
[0037] Reference Figure 4 and Figure 7 The bottom of the pressure block 416 is provided with a driving slope, and the damping block 415 is provided with a passive slope on the side away from the pull rod 3. The driving slope and the passive slope are slidably connected.
[0038] Specifically, as the pressure block 416 moves downward, it compresses the passive inclined surface of the damping block 415 through the driving inclined surface, thereby causing the driving block to move. The rest of the structure is the same as that in Embodiment 1.
[0039] Based on embodiments 1-2, the working principle of this invention is as follows: When sampling deep water, a rapid sampling mode can be used to improve efficiency. The handle 41 is pressed down in advance, causing the pull rod 3 to drive the piston 2 downward. The tension spring 48 stores force, and at the same time, the limiting pin 45 expands outward under the action of the return spring 46. When the piston 2 moves to the lowest position, the limiting pin 45 automatically engages with the annular groove 47 to complete the locking. The water storage tank 1 is then placed in the water. Water enters the interior from the vent at the top of the water storage tank 1, squeezing out the air. The buoyancy of the device decreases and it gradually sinks. After reaching the target depth, the traction cable 43 is pulled up. The traction cable 43 pulls the two limiting pins 45 through the support cable, causing them to retract inward and disengage from the annular groove 47, thus releasing the lock. The tension spring 48 is released instantly, pulling the piston 2 to move upward quickly. A negative pressure is generated inside the water storage tank 1. The external water pressure pushes open the bottom baffle 49, and the water sample quickly flows into the water storage tank 1. After being lifted off the water surface, the gravity of the water sample presses down on the baffle 49, making it fit against the bottom of the tank, thus achieving automatic sealing and preventing leakage.
[0040] When sampling in shallow water, a low-disturbance sampling mode is used to ensure sampling quality. First, the bottom baffle 49 is fixed by the hook 410 and the bend 411 to close the water inlet. Then, the connecting pipe 419 is rotated to align the suction port 421 with the docking port 420. Next, the lifting plate 413 is screwed down to move it down. The driving inclined plane squeezes the passive inclined plane of the damping block 415, so that the damping block 415 presses against the pull rod 3. The device is then put into the water. The counterweight 417 guides the water storage tank 1 to automatically invert, with the suction port 421 facing down. After the traction cable 43 is pulled up to unlock, the pull rod 3 moves slowly up under the constraint of the high friction of the damping block 415, forming a gentle negative pressure. The water flows through the suction port 421, the docking port 420, and the connecting pipe 419 in sequence, and enters the water storage tank 1 smoothly from the receiving cavity, completely avoiding water sample contamination caused by the bottom silt being rolled up due to excessive water intake.
[0041] Example 3, referring to Figures 1-11 The third embodiment of the present invention provides a water sampling method for water pollution detection, comprising the following steps: S1. First, select different sampling modes according to the water depth of the sampling area, and put the water storage tank 1 into the water area. During this process, hold the top of the sleeve 44 to facilitate the retrieval of the water storage tank 1.
[0042] S2. Then, during deep water sampling, the traction cable 43 is pulled to retract the limiting pin 45, causing the tension spring 48 to drive the piston 2 to move upward. The upward movement of the piston 2 creates a negative pressure inside the water storage tank 1, drawing the external water sample into the water storage tank 1. When the sampling water depth is less than the height of the water storage tank 1, the water intake port 421 is positioned downward to slowly draw water through the action of the switching unit, adapting to different water depths through different modes.
[0043] S3. Finally, after enough water sample is drawn into the water storage tank 1, the water storage tank 1 is lifted out of the water surface through the sleeve 44 and retracted. The water sample inside the water storage tank 1 is then discharged by lifting the pressure plate.
[0044] S4. After the water storage tank 1 is retrieved, the water sample inside the water storage tank 1 is taken out, packaged, and sent for testing, thus completing the process from sampling to testing.
[0045] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A water sampling device for water pollution detection, comprising a water storage tank (1), a piston (2) disposed inside the water storage tank (1), and a pull rod (3) disposed on the top of the piston (2), characterized in that: It also includes a pumping mechanism (4) located at the top of the pull rod (3); The pumping mechanism (4) includes a handle (41) symmetrically arranged on the top of the pull rod (3), a take-up and release hole (42) opened at the top of the pull rod (3), a traction cable (43) arranged in the middle and upper inner wall of the take-up and release hole (42), a sleeve (44) sleeved on the outside of the traction cable (43), and limiting pins (45) symmetrically arranged at the bottom of the take-up and release hole (42). The bottom end of the traction cable (43) is fixedly connected to the two limiting pins (45) respectively, and a return spring (46) is arranged in the middle of the two limiting pins (45). The two ends of the valve are fixedly connected to two limit pins (45) respectively, and an annular groove (47) is opened on the inner wall of the water tank (1) near the limit pins (45). A tension spring (48) is sleeved on the outside of the pull rod (3). The two ends of the tension spring (48) are fixedly connected to the piston (2) and the water tank (1) respectively. A baffle (49) is set on the inner wall of the bottom of the water tank (1), a hook (410) is set on the bottom of the baffle (49), a curved groove (411) is opened on the outer wall of the bottom of the water tank (1), and a switching unit is set on the top of the water tank (1).
2. The water sampling device for water pollution detection according to claim 1, characterized in that, The water storage tank (1) has an inlet at the bottom and several exhaust ports arranged in a ring array at the top.
3. The water sampling device for water pollution detection according to claim 1, characterized in that, A connecting plate is provided on the side of the baffle (49) away from the hook (410), and the bottom inner wall of the water tank (1) away from the hook (410) is rotatably connected to the connecting plate.
4. The water sampling device for water pollution detection according to claim 1, characterized in that, The bottom end of the traction cable (43) is symmetrically provided with two support cables, and the bottom ends of the two support cables are respectively fixedly connected to the corresponding limiting pins (45).
5. The water sampling device for water pollution detection according to claim 1, characterized in that, The bottom end of the limiting pin (45) is provided with a positioning hole, and the bottom of the inner wall of the receiving hole (42) is provided with a support shaft, and the outer wall of the support shaft is rotatably connected to the inner wall of the positioning hole.
6. The water sampling device for water pollution detection according to claim 1, characterized in that, The switching unit includes a fixed sleeve (412) set on the top of the water tank (1), a lifting plate (413) set on the outer wall of the fixed sleeve (412), a telescopic hole (414) symmetrically opened on the top of the water tank (1) near the annular groove (47), a damping block (415) set at the bottom of the telescopic hole (414), a pressure block (416) set on the top of the telescopic hole (414), a counterweight block (417) symmetrically set on the outside of the water tank (1), a shell (418) set on the water tank (1) at the middle of the two counterweight blocks (417), a connecting pipe (419) set inside the shell (418), a plurality of linear arrays of docking ports (420) opened on the side of the connecting pipe (419) away from the water tank (1), and a plurality of linear arrays of suction ports (421) opened on the side of the shell (418) away from the water tank (1).
7. The water sampling device for water pollution detection according to claim 6, characterized in that, The top of the outer shell (418) is provided with a receiving cavity, the bottom of which is connected to the interior of the water storage tank (1). The outer wall of the fixing sleeve (412) is provided with threads, and the top of the lifting plate (413) is provided with a threaded hole that extends to the bottom. The threaded hole is threadedly connected to the outer wall of the fixing sleeve (412).
8. The water sampling device for water pollution detection according to claim 6, characterized in that, The bottom of the pressure block (416) is provided with a driving slope, and the side of the damping block (415) away from the pull rod (3) is provided with a passive slope. The driving slope and the passive slope are slidably connected.
9. A water sampling method for water pollution detection, applied to the water sampling device for water pollution detection as described in claim 6, characterized in that, Includes the following steps: First, the water storage tank (1) is placed into the water area, and different sampling modes are selected according to the water depth of the sampling area; Then, during deep water sampling, the limiting pin (45) is contracted by pulling the traction cable (43), and the tension spring (48) drives the piston (2) to move upward. The upward movement of the piston (2) creates negative pressure inside the water storage tank (1), drawing water samples from the outside into the water storage tank (1). When the depth of the sampling water area is less than the height of the water storage tank (1), the water intake port (421) is positioned downward and slowly draws water through the action of the switching unit. Finally, after the water tank (1) has absorbed enough water sample, the water tank (1) is lifted out of the water surface through the sleeve (44) and retrieved.
10. The water sampling method for water pollution detection according to claim 9, characterized in that, After the water storage tank (1) is retrieved, the water sample inside the water storage tank (1) is taken out, repackaged and sent for testing.