A liquid level detection device for water treatment

Abstract

The present invention relates to a liquid level detection device for water treatment applied in the field of water treatment technology, comprising a detection isolation mechanism, the detection isolation mechanism comprising an outer isolation shell and an inner isolation shell installed inside the outer isolation shell, a bearing is installed on the outer isolation shell, the inner isolation shell is rotatably connected to the outer isolation shell through the bearing, and an air guide mechanism is installed through the inner isolation shell; a pressure sensor is installed on the inner wall of the inner isolation shell, a driving member is installed on the inner wall of the outer isolation shell, and the output shaft of the driving member is fixed to the inner isolation shell; a liquid level intelligent controller is installed on the inner wall of the inner isolation shell, and the liquid level intelligent controller is provided with a main control module, an instruction module, and a detection module; in the above-mentioned liquid level detection device for water treatment, when the outer isolation shell is blocked and the liquid level height cannot be measured normally, the blockage is discharged through the air guide mechanism, so that the pressure sensor can detect normally, and there is no need to regularly take out the immersion liquid level meter for cleaning and unblocking.

Description

Technical Field

[0001] The invention relates to a liquid level detection device, in particular to a water treatment liquid level detection device applied in the technical field of water treatment. Background Art

[0002] Water treatment is the process of removing harmful substances that are not necessary for production and life from water through physical, chemical and biological means. It is a process of conditioning water quality by sedimentation, filtration, coagulation, flocculation, corrosion inhibition and scale prevention in order to make it suitable for specific purposes.

[0003] Since social production and life are closely related to water, the application scope of water treatment is very wide, which constitutes a huge industrial application. The water level inside the water treatment tank should be detected during operation to ensure the normal operation of the water treatment system. The liquid level measurement often uses a immersion level gauge, which has a simple structure, is easy to install and use, has a long service life and a wide measurement range. It can measure water, oil, and phases with high viscosity. It is cheap and has high reliability. However, after the installation of the immersion level gauge, if the fluid fluctuation increases and the water flow impacts the immersion level gauge, it will affect the accuracy and stability of the measurement. At the same time, in the case of poor water quality or high water hardness, the pressure hole may be blocked. It is necessary to take out the immersion level gauge regularly for cleaning and unblocking the pressure hole, otherwise it will affect the measurement accuracy. It is inconvenient to take out the immersion level gauge regularly for cleaning and unblocking the pressure hole, which will also have a certain impact on water treatment.

[0004] The invention patent with publication number CN108844595A discloses a submersible liquid level meter, including an adjustable rod with a cable installed inside, one end of the adjustable rod is connected to a meter head, the other end of the adjustable rod passes through a weight and is welded to the top of the weight; a temperature sensor and a pressure sensor are arranged inside the weight, the temperature sensor and the pressure sensor are threadedly connected to the bottom of the adjustable rod, the middle of the weight is filled with silicone oil, a diaphragm is welded to the bottom of the weight, the diaphragms are arranged in a spiral shape, a protective shell is threadedly installed on the bottom of the weight, and a plurality of holes are provided on the protective shell.

[0005] This method can adapt to different liquids and is resistant to high temperature and corrosion. However, when the liquid flow rate is too fast, it will impact the immersion level meter and affect the accuracy and stability of the measurement. At the same time, floating objects, sediments, etc. in the liquid will block the pressure taking hole of the immersion level meter and affect the measurement accuracy. Summary of the invention

[0006] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that when the liquid flow rate is too fast, it will have an impact on the immersion liquid level meter, affecting the accuracy and stability of the measurement. At the same time, floating objects, sediments, etc. contained in the liquid will block the pressure taking hole of the immersion liquid level meter, affecting the measurement accuracy.

[0007] In order to solve the above problems, the present invention provides a liquid level detection device for water treatment, including a detection isolation mechanism, the detection isolation mechanism includes an outer isolation shell and an inner isolation shell installed inside the outer isolation shell, a bearing is installed on the outer isolation shell, the inner isolation shell is rotatably connected with the outer isolation shell through the bearing, and an air guide mechanism is installed through the inner isolation shell for introducing gas into the gap between the inner isolation shell and the outer isolation shell; a pressure sensor is installed on the inner wall of the inner isolation shell, the pressure sensor is used to detect the water pressure at the position where the liquid level detection device is located, a driving member is installed on the inner wall of the outer isolation shell, and the output shaft of the driving member is fixed to the inner isolation shell;

[0008] A liquid level intelligent controller is installed on the inner wall of the inner isolation shell. The liquid level intelligent controller is provided with a main control module, a command module, and a detection module. The main control module is electrically connected to the command module and the detection module respectively, the command module is electrically connected to the air guide mechanism and the driving part respectively, and the detection module is electrically connected to the pressure sensor.

[0009] In the above-mentioned liquid level detection device for water treatment, when the outer isolation shell is blocked and the liquid level height cannot be measured normally, gas is introduced into the gap between the inner isolation shell and the outer isolation shell through the air guide mechanism to discharge the blockage, so that the pressure sensor can detect normally. There is no need to regularly take out the immersion liquid level meter for cleaning and unblocking, and the liquid level height can be measured normally even when the water quality is poor and there is a lot of sediment in the water.

[0010] As a further improvement of the present application, a plurality of through holes 1 are provided on the outer isolation shell, the plurality of through holes 1 are distributed along the circumference of the outer isolation shell, and a filter is provided in the through holes 1.

[0011] As a further improvement of the present application, a supporting member is fixed to the inner wall of the outer isolation shell, and a plurality of through holes 2 are opened on the supporting member.

[0012] As a further improvement of the present application, the inner isolation shell is plugged into the supporting member, and a through hole three corresponding to the through hole two on the supporting member is provided on the inner isolation shell.

[0013] As another improvement of the present application, the air guide mechanism includes an air guide pipe connected to the inner isolation shell, the air guide pipe connects the air source and the annular through pipe, an electromagnetic valve is arranged on the air guide pipe, a plurality of through holes are opened in the annular through pipe, and the instruction module is electrically connected to the air source and the electromagnetic valve.

[0014] As another improved supplement of the present application, an anti-impact mechanism is provided on the outer wall of the outer isolation shell, and a plurality of anti-impact mechanisms are provided, and are arranged corresponding to the through holes opened on the outer isolation shell.

[0015] As another improved supplement of the present application, the anti-impact mechanism includes a connecting seat fixedly mounted on the outer wall of the outer isolation shell, a driving rod is rotatably connected to the connecting seat, the driving rod is slidably connected to a sliding groove provided on the baffle, a locking piece is fixedly mounted on the baffle, and a spring is arranged between the baffle and the outer wall of the outer isolation shell.

[0016] As another improvement of the present application, a stabilizing mechanism is provided on the outer wall of the outer isolation shell, and the stabilizing mechanism includes a stabilizing support shell fixedly installed on the outer wall of the outer isolation shell, an electromagnet is installed on the inner wall of the stabilizing support shell, a magnetic attraction component is installed through the stabilizing support shell, the magnetic attraction component and the stabilizing support shell are connected by spring 2, a through hole 5 is opened on the stabilizing support shell, and the instruction module is electrically connected to the electromagnet.

[0017] As another improvement of the present application, the magnetic attraction component includes a magnetic attraction base with a limiting groove, the magnetic attraction base is fixedly connected to the second spring, and a permanent magnet is fixedly installed in the limiting groove.

[0018] To summarize, the present application can solve the problem that the through hole 1 opened on the outer isolation shell is blocked by floating objects and sediments in the water, causing the liquid level detection device to be unable to detect the current liquid level. When the through hole 1 is blocked, the driving member drives the inner isolation shell to rotate, closes the through hole 3 opened on the inner isolation shell, and then opens the solenoid valve, injects gas into the air guide pipe through the air source, and the gas flows along the air guide pipe to the annular through pipe, and then is sprayed into the gap between the inner isolation shell and the outer isolation shell through the through hole 4 on the annular through pipe. When the air pressure in the gap increases, the gas will be discharged from the through hole 1, and at the same time, the floating objects, sediments, etc. blocked in the through hole will also be brought out, so that the liquid level detection device can return to normal working state. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the three-dimensional structure of the liquid level detection device for water treatment according to the first and second embodiments of the present application;

[0020] Figure 2 This is a schematic diagram of the structure of the air guide mechanism of the first and second embodiments of the present application;

[0021] Figure 3 A schematic cross-sectional view of the outer isolation shell of the first and second embodiments of the present application;

[0022] Figure 4 This is a schematic diagram of a liquid level intelligent controller according to the first embodiment of the present application;

[0023] Figure 5 This is a physical diagram of the anti-impact mechanism structure of the first and second embodiments of the present application;

[0024] Figure 6 This is a schematic diagram of the stabilizing mechanism structure of the first and second implementation modes of the present application;

[0025] Figure 7 This is a schematic structural diagram of the stabilizing mechanism of the first and second embodiments of the present application from another angle;

[0026] Figure 8 This is a schematic diagram of the liquid level intelligent controller according to the second embodiment of the present application.

[0027] Description of the numbers in the figure:

[0028] 1. Detection isolation mechanism; 101. Outer isolation shell; 102. Inner isolation shell; 103. Bearing; 104. Filter; 105. Supporting member; 106. Through hole one; 107. Through hole two; 108. Through hole three; 2. Anti-impact mechanism; 201. Baffle; 202. Sliding groove; 203. Driving rod; 204. Connecting seat; 205. Locking member; 206. Spring one; 3. Air guide mechanism; 301. Air guide pipe; 302. Annular through pipe; 303. Solenoid valve; 4. Stabilizing mechanism; 401. Stabilizing support shell; 402. Magnetic suction component; 403. Spring two; 404. Electromagnet; 405. Through hole five; 406. Limiting groove; 5. Liquid level intelligent controller; 6. Pressure sensor; 7. Driving member. DETAILED DESCRIPTION

[0029] Two implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0030] The first implementation method:

[0031] Figure 1-Figure 4 A liquid level detection device for water treatment is shown, comprising a detection isolation mechanism 1, the detection isolation mechanism 1 comprising an outer isolation shell 101 and an inner isolation shell 102 installed inside the outer isolation shell 101, a bearing 103 is installed on the outer isolation shell 101, the inner isolation shell 102 is rotatably connected to the outer isolation shell 101 through the bearing 103, and an air guide mechanism 3 is installed through the inner isolation shell 102 for introducing gas into the gap between the inner isolation shell 102 and the outer isolation shell 101; a pressure sensor 6 is installed on the inner wall of the inner isolation shell 102, and the pressure sensor 6 is used to detect the water pressure at the position where the liquid level detection device is located; a driving member 7 is installed on the inner wall of the outer isolation shell 101, and the output shaft of the driving member 7 is fixed to the inner isolation shell 102;

[0032] A liquid level intelligent controller 5 is installed on the inner wall of the inner isolation shell 102. The liquid level intelligent controller 5 is provided with a main control module, a command module, and a detection module. The main control module is electrically connected to the command module and the detection module respectively, the command module is electrically connected to the air guide mechanism 3 and the driving part 7 respectively, and the detection module is electrically connected to the pressure sensor 6.

[0033] When measuring the liquid level, a plurality of through holes 106 are provided on the outer isolation shell 101, and the plurality of through holes 106 are distributed along the circumference of the outer isolation shell 101. The liquid level detection device is put into the liquid tank, and the liquid enters the gap between the inner isolation shell 102 and the outer isolation shell 101 from each through hole 106. A filter 104 is provided in the through hole 106 to block floating objects and sediments in the liquid outside the outer isolation shell 101. After the liquid enters the gap between the inner isolation shell 102 and the outer isolation shell 101, the liquid level in the gap gradually rises. A supporting member 105 is fixed to the inner wall of the outer isolation shell 101, and a plurality of through holes 107 are provided on the supporting member 105. The shell 102 is plugged into the supporting member 105. After the liquid level rises to the position of the through hole 107, it will flow into the inner isolation shell 102 from the through hole 107. The inner isolation shell 102 is provided with a through hole 108 corresponding to the through hole 107 on the supporting member 105. The liquid flows into the inner isolation shell 102 along the through hole 108. As the liquid level detection device is immersed in the liquid tank, the liquid eventually fills the entire inner isolation shell 102 and the gap between the inner isolation shell 102 and the outer isolation shell 101. At this time, as the liquid level detection device sinks to the bottom of the liquid tank under the action of gravity, the inside and outside of the liquid level detection device will be filled with liquid, so that the pressure sensor 6 can detect the pressure of the liquid.

[0034] When the main control module of the liquid level intelligent controller 5 receives the pressure information of the pressure sensor 6 sent by the detection module and the pressure information does not change significantly for a period of time, it will be judged that the through hole 106 may be blocked. At this time, the main control module will control the action of the driving member 7 through the instruction module. The action of the driving member 7 drives the inner isolation shell 102 to rotate, and the inner isolation shell 102 rotates to a preset position (a preset position is preset in the main control module), so that the through hole 3 108 opened on the inner isolation shell 102 no longer corresponds to the through hole 2 107 opened on the supporting member 105, and the interior of the inner isolation shell 102 is separated from the gap between the inner isolation shell 102 and the outer isolation shell 101, so that the pressure change in the gap between the inner isolation shell 102 and the outer isolation shell 101 will not affect the pressure sensor 6, and the instruction module then controls the air guide mechanism 3, the air guide mechanism 3 includes an air guide pipe 301 connected to the inner isolation shell 102, the air guide pipe 301 is connected to the air source and the annular through pipe 302, and the air guide pipe 301 is provided with a solenoid valve 303, the annular through-tube 302 is provided with a plurality of through-holes four, the command module is electrically connected with the gas source and the solenoid valve 303, the command module controls the solenoid valve 303 to open, and then controls the gas source to inject the compressed gas into the annular through-tube 302 along the air guide tube 301, the compressed gas flows along the annular through-tube 302, and enters the gap between the inner isolation shell 102 and the outer isolation shell 101 from the through-hole four of the annular through-tube 302, as the amount of gas injected into the gap by the gas source increases, the pressure in the gap increases, and the liquid in the gap is discharged, the liquid is mainly discharged along the through-hole 106, during the liquid discharge process, the filter screen 104 arranged in the through-hole 106 will be flushed, the liquid flushing the filter screen 104 will take away a part of the floating matter and sediment attached to the filter screen 104, when the liquid in the gap is emptied, the compressed gas will be discharged from the through-hole 106, the high-speed compressed gas flushes the filter screen 104, and effectively takes the floating matter and sediment attached to the filter screen 104 away from the filter screen 104.

[0035] At this time, the instruction module controls the gas source to stop injecting compressed gas, controls the solenoid valve 303 to close, and then controls the driving member 7 to move in the opposite direction. The reverse movement of the driving member 7 will drive the inner isolation shell 102 to rotate in the opposite direction, and rotate the inner isolation shell 102 in the opposite direction to the initial position, so that the through hole three 108 of the inner isolation shell 102 and the through hole two 107 of the supporting member 105 correspond to each other again, so that the inner isolation shell 102 and the gap between the inner isolation shell 102 and the outer isolation shell 101 are reconnected, and the liquid flows into the gap from the through hole one 106 again, and the gas in the gap will flow out from the gap in the bearing 103 at the connection between the inner isolation shell 102 and the outer isolation shell 101. After waiting for a period of time, the liquid will refill the gap between the inner isolation shell 102 and the inner isolation shell 102 and the outer isolation shell 101, so that the main control module can receive the accurate pressure information detected by the pressure sensor 6 sent by the detection module.

[0036] The second implementation method:

[0037] Figure 1 , Figure 2 as well as Figure 5-Figure 8 A liquid level detection device for water treatment is shown. Different from the first embodiment, when performing liquid level detection, the liquid level detection device may not be completely stabilized at the bottom of the liquid tank due to liquid buoyancy, a large amount of sediment at the bottom of the liquid tank, etc., resulting in deviations in the measured liquid level data. It is also possible that a large amount of liquid in the liquid tank is used during the treatment process, which increases the liquid flow rate and impacts the liquid level detection device, affecting the accuracy and stability of the liquid level measured by the liquid level detection device.

[0038] Therefore, a stabilizing mechanism 4 is arranged on the outer wall of the outer isolation shell 101, and the stabilizing mechanism 4 comprises a stabilizing support shell 401 fixedly mounted on the outer wall of the outer isolation shell 101, an electromagnet 404 is installed on the inner wall of the stabilizing support shell 401, a magnetic suction component 402 is installed through the stabilizing support shell 401, the magnetic suction component 402 is connected to the stabilizing support shell 401 through a spring 2 403, a through hole 5 405 is provided on the stabilizing support shell 401, the instruction module is electrically connected to the electromagnet 404, the magnetic suction component 402 comprises a magnetic suction base with a limiting groove 406, and the magnetic suction base The seat is fixedly connected to the spring 2 403, and a permanent magnet is fixedly installed on the magnetic base. After the liquid level detection device is put into the liquid tank, the liquid level detection device will move to the bottom of the tank under the action of gravity. When the liquid level detection device moves to the bottom of the tank, the permanent magnet in the magnetic component 402 of the stabilizing mechanism 4 will be adsorbed on the bottom of the tank. At the same time, the main control module controls the electromagnet 404 through the instruction module, driving the stable support shell 401 to approach the magnetic component 402, compressing the spring, so that the magnetic base fits on the electromagnet 404, enhancing the magnetic force of the permanent magnet, and improving the stability of the liquid level detection device.

[0039] It is worth mentioning that if there are too many sediments on the bottom of the tank and the liquid level detection device cannot fall to the bottom of the tank, the main control module will control the solenoid valve 303 to open through the command module, and then control the gas source to inject compressed gas into the liquid level detection device. After the compressed gas empties the liquid in the liquid level detection device, it will be discharged from the through hole 106 of the outer isolation shell 101. In the process of discharging the gas, the flow of the liquid will be accelerated. The flow of the liquid can bring up the sediment at the bottom of the tank, so that the liquid level detection device can fall smoothly to the bottom of the tank.

[0040] After the liquid level detection device can be firmly fixed on the bottom of the tank, in order to reduce the influence of liquid flow on the accuracy and stability of the measurement result of the liquid level detection device, an anti-shock mechanism 2 is provided on the outer wall of the outer isolation shell 101. The anti-shock mechanism 2 is provided in plurality and is provided corresponding to the through hole 106 opened on the outer isolation shell 101. The anti-shock mechanism 2 is provided to block the liquid that directly flows into the through hole 106 opened on the outer isolation shell 101, so that it cannot directly impact the through hole 106 and affect the water pressure inside the liquid level detection device, thereby ensuring the accuracy and stability of the measurement result of the liquid level detection device. The anti-shock mechanism 2 includes a connecting seat 204 fixedly installed on the outer wall of the outer isolation shell 101, and a rotatable connection on the connecting seat 204. There is a driving rod 203, which is slidably connected to a sliding groove 202 provided on the baffle 201. A locking piece 205 is fixedly installed on the baffle 201. A spring 206 is provided between the baffle 201 and the outer wall of the outer isolation shell 101. When the liquid level detection device has not yet been put into the liquid tank, the baffle 201 is tightly attached to the outer isolation shell 101 to compress the spring 206. The locking piece 205 installed on the baffle 201 is inserted into the through hole 405 of the stabilizing mechanism 4, and the end of the locking piece 205 is stuck in the limiting groove 406 provided on the magnetic base. At this time, the spring 2 403 is in an expanded state, pushing the magnetic suction component 402 outward, so that the limiting groove 406 locks the position of the locking piece 205, thereby locking the position of the baffle 201.

[0041] After the stabilizing mechanism 4 is adsorbed on the bottom of the tank, the main control module controls the electromagnet 404 through the command module to drive the stabilizing support shell 401 to approach the magnetic component 402. A permanent magnet is fixedly installed in the limiting groove 406 of the magnetic component 402 to compress the spring so that the magnetic base fits on the electromagnet 404. The magnetic component 402 no longer pushes outward, and the limiting groove on the magnetic base can no longer lock the locking piece 205. The spring 206 pops open, pushing the baffle 201 to move outward. The baffle 201 moves outward, driving one end of the driving rod 203 to slide toward the center of the baffle 201 along the sliding groove 202 with the connecting seat 204 as the axis, until the driving rod 203 slides to the point where the pulling force on the baffle 201 is equal to the thrust of the spring 206, and the baffle 201 stops moving. At this time, the baffle 201 will block the surrounding of the outer isolation shell 101 and block the liquid rushing directly toward the through hole 106, so that the liquid level detection device can accurately and stably detect the liquid level.

[0042] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A liquid level detection device for water treatment, characterized in that: The detection isolation mechanism (1) comprises an outer isolation shell (101) and an inner isolation shell (102) installed inside the outer isolation shell (101); a bearing (103) is installed on the outer isolation shell (101); the inner isolation shell (102) is rotatably connected to the outer isolation shell (101) via the bearing (103); an air guide mechanism (3) is installed through the inner isolation shell (102) for introducing gas into the gap between the inner isolation shell (102) and the outer isolation shell (101); a pressure sensor (6) is installed on the inner wall of the inner isolation shell (102); the pressure sensor (6) is used to detect the water pressure at the location of the liquid level detection device; a driving member (7) is installed on the inner wall of the outer isolation shell (101); the output shaft of the driving member (7) is fixed to the inner isolation shell (102); A liquid level intelligent controller (5) is installed on the inner wall of the inner isolation shell (102), and the liquid level intelligent controller (5) is provided with a main control module, a command module, and a detection module, the main control module is electrically connected to the command module and the detection module respectively, the command module is electrically connected to the air guide mechanism (3) and the driving member (7) respectively, and the detection module is electrically connected to the pressure sensor (6); The outer isolation shell (101) is provided with a plurality of through holes one (106), the plurality of through holes one (106) are distributed along the circumference of the outer isolation shell (101), and a filter screen (104) is provided in the through holes one (106); A supporting member (105) is fixed to the inner wall of the outer isolation shell (101), and a plurality of second through holes (107) are formed on the supporting member (105); The inner isolation shell (102) is plugged into the supporting member (105), and a third through hole (108) corresponding to the second through hole (107) on the supporting member (105) is provided on the inner isolation shell (102); The air guide mechanism (3) comprises an air guide pipe (301) penetrating and connected to the inner isolation shell (102), the air guide pipe (301) communicating with an air source and an annular through pipe (302), an electromagnetic valve (303) being arranged on the air guide pipe (301), a plurality of through holes (4) being provided on the annular through pipe (302), and the instruction module being electrically connected to the air source and the electromagnetic valve (303); The driving member (7) is actuated to drive the inner isolation shell (102) to rotate, and the inner isolation shell (102) rotates to a preset position, so that the third through hole (108) provided on the inner isolation shell (102) does not correspond to the second through hole (107) provided on the supporting member (105), and the interior of the inner isolation shell (102) is separated from the gap between the inner isolation shell (102) and the outer isolation shell (101), so that the pressure change in the gap between the inner isolation shell (102) and the outer isolation shell (101) will not affect the pressure sensor (6).

2. A liquid level detection device for water treatment according to claim 1, characterized in that: The outer wall of the outer isolation shell (101) is provided with an anti-impact mechanism (2), and a plurality of the anti-impact mechanisms (2) are provided and are arranged corresponding to through holes (106) opened on the outer isolation shell (101).

3. A liquid level detection device for water treatment according to claim 2, characterized in that: The anti-impact mechanism (2) comprises a connection seat (204) fixedly mounted on the outer wall of the outer isolation shell (101); a driving rod (203) is rotatably connected to the connection seat (204); the driving rod (203) is slidably connected to a sliding groove (202) provided on the baffle plate (201); a locking member (205) is fixedly mounted on the baffle plate (201); and a spring 1 (206) is provided between the baffle plate (201) and the outer wall of the outer isolation shell (101).

4. A liquid level detection device for water treatment according to claim 1, characterized in that: The outer wall of the outer isolation shell (101) is provided with a stabilizing mechanism (4), and the stabilizing mechanism (4) comprises a stabilizing support shell (401) fixedly mounted on the outer wall of the outer isolation shell (101), an electromagnet (404) is mounted on the inner wall of the stabilizing support shell (401), a magnetic attraction component (402) is installed through the stabilizing support shell (401), the magnetic attraction component (402) is connected to the stabilizing support shell (401) via a second spring (403), a fifth through hole (405) is provided on the stabilizing support shell (401), and the instruction module is electrically connected to the electromagnet (404).

5. A liquid level detection device for water treatment according to claim 4, characterized in that: The magnetic attraction component (402) comprises a magnetic attraction base with a limiting groove (406), the magnetic attraction base is fixedly connected to the second spring (403), and a permanent magnet is fixedly installed in the limiting groove (406).

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