Non-contact photoelectric liquid level sensor

Abstract

The invention relates to the technical field of photoelectric liquid level sensors, and particularly discloses a non-contact photoelectric liquid level sensor which comprises a protective shell, a sensor body is installed at the bottom end of the inner side of the protective shell, a shell cover is connected to the top end of the protective shell in a clamped mode and covers the top end of the protective shell, and an incident light indicating lamp is installed at the top end of the shell cover. By the adoption of the structure, ventilation and heat dissipation of the sensor body can be facilitated through the ventilation opening, a large amount of dust can be prevented from entering the sensor body through the first dustproof plate and the second dustproof plate, meanwhile, circulating air can enter the protective shell in a bending mode, the filtering plate can conduct good secondary filtering on convection ventilation, and therefore the good dustproof and heat dissipation effect can be achieved; when the position where the sensor body is used needs a good sealing effect, a user can directly pull down the sealing plate according to the sliding principle, the sealing plate can completely cover the position of the ventilation opening, and therefore the good sealing protection effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of photoelectric liquid level sensors, in particular to a non-contact photoelectric liquid level sensor. Background Art

[0002] The non-contact photoelectric liquid level sensor is an innovative liquid level monitoring technology. It works on the principle of optical sensing and does not require direct contact with the liquid to be measured. The sensor determines the liquid level by emitting and receiving light and detecting the refraction or absorption of light. This sensor has the advantages of high precision, high reliability, and no movement of mechanical parts. It is suitable for liquid level monitoring of various small household appliances and equipment. It is easy to install and simple to maintain, especially suitable for occasions where water tanks need to be moved frequently or equipment needs to be kept clean.

[0003] A Chinese patent with announcement number "CN215217751U" discloses a non-contact photoelectric liquid level sensor, which includes: a housing assembly, a PCB board, a pair of tubes assembly and a wire sealing gasket. The PCB board is arranged in the housing assembly. The pair of tubes assembly includes: a transmitting pair of tubes and a receiving pair of tubes. The transmitting pair of tubes is welded on the PCB. The transmitting pair of tubes is welded on the PCB and is located on one side of the transmitting pair of tubes.

[0004] However, the above structure still has some shortcomings, because there are many small electrical structures in the sensor, and the installation point of the sensor is generally inside the machine, and the shell structure of the sensor generally does not have a relative heat dissipation structure, and its heat dissipation method is also carried out by opening a heat dissipation port. This heat dissipation method will cause dust or pollutants to enter the sensor, thereby causing damage to the sensor. In addition, according to the different devices used by the sensor, the sensor must also have a relative waterproof sealing structure, so that the sensor with a heat dissipation structure and the sensor with a waterproof sealing structure must be used separately, which increases the cost and reduces the scope of use of the sensor itself. Summary of the invention

[0005] The object of the present invention is to provide a non-contact photoelectric liquid level sensor to solve the problem of low sensor usage range mentioned in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides a non-contact photoelectric liquid level sensor, including a protective shell, a sensor body is installed at the inner bottom end of the protective shell, a shell cover is clamped at the top of the protective shell, the shell cover covers the top of the protective shell, a light input indicator light is installed at the top of the shell cover, a wire is provided at the top of the shell cover, a switching switch is provided at the top of the shell cover, a limiting groove is provided on one side of the protective shell, a vent is provided on one side of the limiting groove, the vent is communicated with the inner side of the protective shell, a filter plate is slidably connected to the inner wall of the vent, the filter plate covers the inner side of the vent, a limiting frame is inserted on one side of the limiting groove, a first dustproof plate and a second dustproof plate are fixedly connected to the inner side of the limiting frame, the position of the second dustproof plate corresponds to the position of the filter plate, a sealing plate is slidably connected to the inner wall of the protective shell, a second protrusion is fixedly connected to the other side of the sealing plate, and the sealing plate covers the other side of the vent.

[0007] Furthermore, a first slide groove matching the filter plate is opened on the inner wall of the vent, and the filter plate is slidably connected to the inner wall of the vent through the first slide groove. A second slide groove matching the sealing plate is opened on the inner wall of the protective shell, and the sealing plate is slidably connected to the inner wall of the protective shell through the second slide groove.

[0008] Furthermore, a first groove is opened at the inner bottom end of the vent, and a magnet is fixedly connected to the inner bottom end of the first groove. The magnet covers the inner side of the first groove, and the bottom end of the filter plate is attached to the top end of the magnet. The bottom end of the filter plate is made of magnetically attractive material.

[0009] Furthermore, a second groove is opened on the inner wall of the protective shell, and a second sealing ring is fixedly connected to the inner side of the second groove. The second sealing ring covers the inner side of the second groove, and the other side of the second sealing ring is attached to one side of the sealing plate.

[0010] Furthermore, a slot is provided on one side of the limit groove, and an insert block matching the slot is fixedly connected to the other side of the limit frame. The insert block is fixedly connected to the four sides of the other side of the limit frame near the corners, and the insert block is inserted into the inner side of the slot. The limit frame is inserted into one side of the limit groove through the slot and the insert block.

[0011] Furthermore, a positioning groove is provided at the top of the protective shell, and a positioning block matching the positioning groove is fixedly connected to the bottom of the shell cover. The positioning block is fixedly connected to the four sides of the bottom of the shell cover near the corners, and the positioning block is clamped on the inner side of the positioning groove.

[0012] Furthermore, a first card slot is provided at the top of the shell cover, the first card slot extends to the inside of the protective shell, a second card slot is provided on the inner wall of the first card slot, a circular groove is provided at the inner bottom end of the first card slot, a first card block is clamped on the inner side of the first card slot, a second card block matching the second card slot is fixedly connected to the outer side of the first card block, and the second card block is clamped on the inner side of the circular groove.

[0013] Furthermore, a retaining spring matching the second clamping block is installed at the inner bottom end of the circular groove, the top end of the retaining spring is clamped at the bottom end of the second clamping block, the second clamping block is clamped to the inner side of the circular groove through the retaining spring, the top end of the first clamping block is fixedly connected to a sealing block, the sealing block covers the top end of the first clamping groove, the top end of the sealing block is fixedly connected to a first protrusion, and the shape of the corner of the first protrusion is arc-shaped.

[0014] Furthermore, a first sealing ring is fixedly connected to the top of the protective shell, the first sealing ring is located close to the inner side of the first clamping block, and a sealing groove matching the first sealing ring is opened at the bottom end of the shell cover, and the first sealing ring covers the inner side of the sealing groove.

[0015] Furthermore, a rectangular opening is opened on the front side of the protective shell, the rectangular opening is communicated with the inner side of the protective shell, and a transparent glass is fixedly connected to the inner side of the rectangular opening, and the transparent glass covers the inner side of the rectangular opening.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] Firstly, in the present invention, when in use, the vents can facilitate ventilation and heat dissipation of the sensor body, and the first dustproof plate and the second dustproof plate can effectively block dust and pollutants in the air to prevent a large amount of dust from entering, and also allow the air flow to enter the protective shell in a roundabout way, so that the filter plate and the air flow can be in closer contact, thereby enabling the filter plate to perform good secondary filtration of the air flow, so as to achieve good dustproof and heat dissipation effects; when the points where the sensor body is used require good sealing effects, the user can directly pull down the sealing plate through the sliding principle, and the sealing plate can completely cover the vent points, thereby achieving good sealing and protection effects, and can effectively increase the use range of the sensor body.

[0018] Secondly, in the present invention, due to the presence of the plug block, the insertion of the plug block can effectively limit the position of the limit frame to avoid its displacement, and it is also convenient for the user to disassemble it individually to clean or maintain its inner structure at a later time. The adsorption of the magnet can effectively limit the position of the filter plate to avoid its displacement. When it is necessary to disassemble it individually for maintenance or cleaning at a later time, it can be directly pulled out through the first slide groove. Due to the presence of the second sealing ring, it can fit together with the sealing plate, which can effectively improve the sealing effect of the sealing plate on the vent. At the same time, the rubber-type second sealing ring has good anti-slip ability to avoid displacement of the sealing plate after closing.

[0019] Thirdly, in the present invention, due to the existence of the first clamping block, it is convenient to insert the second clamping block into the circular groove. The second clamping block is adjusted to a point that is not corresponding to the second clamping slot, so that the shell cover point can be effectively clamped. The clamping of the retaining spring can secondary improve the stability of the clamping of the second clamping block point to avoid its displacement. The insertion of the positioning block can effectively improve the accuracy of the insertion of the first clamping block point while limiting the shell cover point. When it needs to be removed later, the second clamping block is rotated to the point corresponding to the second clamping slot, and then the first clamping block is directly pulled out, and finally the positioning block is pulled out of the positioning slot. While achieving the convenience of later disassembly and assembly of the shell cover, it is also more conducive to the user's later inspection or maintenance of the inner structure of the protective shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 It is a schematic diagram of the shell cover structure in the present invention;

[0022] Figure 3 It is a schematic diagram of the inner structure of the protective shell in the present invention;

[0023] Figure 4 For the present invention Figure 3 A schematic diagram of the enlarged structure of part A;

[0024] Figure 5 It is a schematic diagram of the inner structure of the vent in the present invention;

[0025] Figure 6 For the present invention Figure 5 A schematic diagram of the enlarged structure of part B;

[0026] Figure 7 It is a schematic diagram of the inner structure of the limiting groove in the present invention;

[0027] Figure 8 It is a schematic diagram of the limit frame structure in the present invention.

[0028] In the figure: 1. protective shell; 2. sensor body; 3. positioning groove; 4. first sealing ring; 5. shell cover; 6. positioning block; 7. sealing groove; 8. first clamping groove; 9. second clamping groove; 10. circular groove; 11. retaining spring; 12. first clamping block; 13. second clamping block; 14. sealing block; 15. first protrusion; 16. wire; 17. switching switch; 18. light-incoming indicator light; 19. rectangular opening; 20. transparent glass; 21. limiting groove; 22. ventilation port; 23. filter plate; 24. first slide groove; 25. first groove; 26. magnet; 27. second groove; 28. second sealing ring; 29. ​​second slide groove; 30. sealing plate; 31. second protrusion; 32. slot; 33. limiting frame; 34. first dustproof plate; 35. second dustproof plate; 36. plug-in block. DETAILED DESCRIPTION

[0029] Example

[0030] See also Figure 1-Figure 8In an embodiment of the present invention, a non-contact photoelectric liquid level sensor includes a protective shell 1, a sensor body 2 is installed at the inner bottom end of the protective shell 1, a shell cover 5 is clamped at the top of the protective shell 1, the shell cover 5 covers the top of the protective shell 1, a light input indicator 18 is installed at the top of the shell cover 5, a wire 16 is provided at the top of the shell cover 5, a switch 17 is provided at the top of the shell cover 5, a limiting groove 21 is provided on one side of the protective shell 1, a vent 22 is provided on one side of the limiting groove 21, the vent 22 is communicated with the inner side of the protective shell 1, a filter plate 23 is slidably connected to the inner wall of the vent 22, the filter plate 23 covers the inner side of the vent 22, and one side of the limiting groove 21 is plugged into A limit frame 33 is provided, and a first dustproof plate 34 and a second dustproof plate 35 are fixedly connected to the inner side of the limit frame 33. The position of the second dustproof plate 35 corresponds to the position of the filter plate 23. A sealing plate 30 is slidably connected to the inner wall of the protective shell 1, and a second protrusion 31 is fixedly connected to the other side of the sealing plate 30. The sealing plate 30 covers the other side of the vent 22. The non-contact photoelectric liquid level sensor is a liquid level detection device based on the optical sensing principle. Its basic structure includes a transmitter, a receiver and a light-transmitting light cone. The transmitter emits infrared light, and the light is refracted through the light cone and completely returns to the receiver when there is no water; when there is water, the light is refracted into the water, and the light received by the receiver is reduced. The sensor body 2 judges the liquid level according to the change of light received by the receiver. When the liquid level rises, more light is refracted by the liquid, the light received by the receiver decreases, and the sensor outputs a corresponding signal to realize non-contact liquid level monitoring. The sensor body 2 does not need to be in direct contact with the liquid, and has the advantages of high precision, easy installation, and low maintenance cost. When in use, the opening of the vent 22 is beneficial to the ventilation and heat dissipation of the sensor body 2. The first dustproof plate 34 and the second dustproof plate 35 can effectively block dust and pollutants in the air to avoid a large amount of dust from entering. At the same time, the flow ventilation can also enter the protective shell 1 in a roundabout way, so that the filter plate 23 is in closer contact with the flow ventilation, so that the filter plate 23 can perform good secondary filtration on the flow ventilation to achieve a good dust-proof and heat-dissipating effect. When the point where the sensor body 2 is used requires a good sealing effect, the user can directly pull down the sealing plate 30 through the sliding principle, and the sealing plate 30 can completely cover the vent 22 point, thereby achieving a good sealing and protective effect.

[0031] See also Figures 1 to 6A first slide groove 24 matching the filter plate 23 is provided on the inner wall of the vent 22, and the filter plate 23 is slidably connected to the inner wall of the vent 22 through the first slide groove 24. A second slide groove 29 matching the sealing plate 30 is provided on the inner wall of the protective shell 1, and the sealing plate 30 is slidably connected to the inner wall of the protective shell 1 through the second slide groove 29. Due to the opening of the first slide groove 24, the sliding point of the filter plate 23 can be effectively pulled, and it is also convenient for the user to disassemble and install the filter plate 23 later. Due to the opening of the second slide groove 29, the sliding direction of the sealing plate 30 can be effectively pulled, and it is also convenient for the user to disassemble the sealing plate 30 according to the use requirements of the sensor body 2.

[0032] See also Figures 1 to 6 A first groove 25 is provided at the inner bottom end of the vent 22, and a magnet 26 is fixedly connected to the inner bottom end of the first groove 25. The magnet 26 covers the inner side of the first groove 25, and the bottom end of the filter plate 23 is in contact with the top end of the magnet 26. The bottom end of the filter plate 23 is made of a magnetic material. Due to the presence of the magnet 26, the adsorption of the magnet 26 can effectively limit the position of the filter plate 23 to prevent it from being displaced. When it needs to be disassembled separately for maintenance or cleaning later, it can also be directly pulled out through the first slide groove 24.

[0033] See also Figures 1 to 6 A second groove 27 is provided on the inner wall of the protective shell 1, and a second sealing ring 28 is fixedly connected to the inner side of the second groove 27. The second sealing ring 28 covers the inner side of the second groove 27, and the other side of the second sealing ring 28 is in contact with one side of the sealing plate 30. Due to the existence of the second sealing ring 28, it can fit with the sealing plate 30, which can effectively improve the sealing effect of the sealing plate 30 on the vent 22. At the same time, the second sealing ring 28 is a rubber product. The rubber-type second sealing ring 28 has good anti-slip ability to avoid displacement of the sealing plate 30 after closing, thereby also having a good limiting effect.

[0034] See also Figure 7 and Figure 8 A slot 32 is provided on one side of the limit slot 21, and an insert block 36 matching the slot 32 is fixedly connected to the other side of the limit frame 33. The insert block 36 is fixedly connected to the four sides of the other side of the limit frame 33 near the corners, and the insert block 36 is inserted into the inner side of the slot 32. The limit frame 33 is inserted into one side of the limit slot 21 through the slot 32 and the insert block 36. Due to the existence of the insert block 36, the insertion of the insert block 36 can effectively limit the point position of the limit frame 33 to prevent it from displacement, and it is also convenient for the user to disassemble it individually later to clean or maintain its inner structure.

[0035] See also Figures 1 to 4The top of the protective shell 1 is provided with a positioning groove 3, and the bottom of the shell cover 5 is fixedly connected with a positioning block 6 matching the positioning groove 3. The positioning block 6 is fixedly connected to the four sides of the bottom of the shell cover 5 near the corners. The positioning block 6 is snapped into the inner side of the positioning groove 3. The top of the shell cover 5 is provided with a first card slot 8, and the first card slot 8 extends to the inside of the protective shell 1. A second card slot 9 is provided on the inner wall of the first card slot 8. A circular groove 10 is provided at the inner bottom of the first card slot 8. The inner wall of the first card slot 8 is provided with a second card slot 9. The side is clamped with a first clamping block 12, and the outer side of the first clamping block 12 is fixedly connected with a second clamping block 13 matching the second clamping groove 9, the second clamping block 13 is clamped to the inner side of the circular groove 10, and a clamping spring 11 matching the second clamping block 13 is installed at the inner bottom end of the circular groove 10, and the top of the clamping spring 11 is clamped to the bottom end of the second clamping block 13, and the second clamping block 13 is clamped to the inner side of the circular groove 10 through the clamping spring 11, and the top of the first clamping block 12 is fixedly connected with a sealing block 14, and the sealing block 1 4 covers the top of the first card slot 8, and the top of the sealing block 14 is fixedly connected with the first protrusion 15, and the shape of the corner of the first protrusion 15 is arc-shaped. Due to the existence of the first card block 12, it is convenient for the second card block 13 to be inserted into the circular groove 10. The second card block 13 is adjusted to a point position that is not mutually corresponding to the second card slot 9, so that the shell cover 5 can be effectively clamped. The clamping of its clamping spring 11 can secondary improve the stability of the clamping of the second card block 13 to avoid its displacement. The insertion of its positioning block 6 can effectively improve the accuracy of the insertion of the first card block 12 while limiting the point position of the shell cover 5. When it needs to be disassembled later, the second card block 13 is rotated to the point position corresponding to the second card slot 9, and then the first card block 12 is directly pulled out, and finally the positioning block 6 is pulled out of the positioning slot 3. While achieving the convenience of disassembling and assembling the shell cover 5 in the later stage, it is also more conducive to the user to check or maintain the inner structure of the protective shell 1 in the later stage.

[0036] See also Figures 1 to 4 A first sealing ring 4 is fixedly connected to the top of the protective shell 1. The first sealing ring 4 is located on the inner side close to the first clamping block 12. A sealing groove 7 matching the first sealing ring 4 is opened at the bottom of the shell cover 5. The first sealing ring 4 covers the inner side of the sealing groove 7. Due to the existence of the first sealing ring 4, the first sealing ring 4 can effectively seal the connection point between the protective shell 1 and the shell cover 5, thereby effectively improving the sealing effect of the overall protective shell 1, so as to improve the sealing and dustproof performance of the overall shell.

[0037] See also Figure 1A rectangular opening 19 is provided on the front side of the protective shell 1, and the rectangular opening 19 is communicated with the inner side of the protective shell 1. A transparent glass 20 is fixedly connected to the inner side of the rectangular opening 19, and the transparent glass 20 covers the inner side of the rectangular opening 19. Due to the opening of the rectangular opening 19, the user can directly view the inner side of the protective shell 1 through the transparent glass 20 without opening the shell cover 5, which is beneficial for the user to observe the operating status of the sensor body 2 at all times, so as to improve the safety protection of the sensor body 2.

[0038] The working principle of the present invention is: when in use, due to the opening of the vent 22, the ventilation and heat dissipation of the sensor body 2 is facilitated, and the first dustproof plate 34 and the second dustproof plate 35 can effectively block the dust and pollutants in the air to prevent a large amount of dust from entering, and at the same time, the air flow can enter the protective shell 1 in a roundabout way, so that the filter plate 23 and the air flow are in closer contact, so that the filter plate 23 can perform a good secondary filtration on the air flow, so as to achieve a good dust-proof and heat-dissipating effect. When the point where the sensor body 2 is used requires a good sealing effect, the user can directly pull down the sealing plate 30 through the sliding principle, and the sealing plate 30 can completely cover the vent 22 point, so as to achieve a good sealing and protection effect. 4 is opened, so that the sliding point of the filter plate 23 can be effectively pulled, and it is also convenient for the user to disassemble and install the filter plate 23 at a later time. Due to the opening of the second slide groove 29, the sliding direction of the sealing plate 30 can be effectively pulled, and it is also convenient for the user to disassemble the sealing plate 30 according to the use requirements of the sensor body 2. Due to the existence of the magnet 26, the adsorption of the magnet 26 can effectively limit the point of the filter plate 23 to avoid its displacement. When it is necessary to disassemble it separately for maintenance or cleaning at a later time, it can also be directly pulled out through the first slide groove 24. Due to the existence of the second sealing ring 28, it can fit with the sealing plate 30, which can effectively improve the sealing effect of the sealing plate 30 on the vent 22. At the same time, the second sealing ring 28 is a rubber product. The rubber-type second sealing ring 28 has good anti-slip ability to prevent the sealing plate 30 from being displaced after closing, thereby also having a good limiting effect. Due to the existence of the plug block 36, the insertion of the plug block 36 can effectively limit the point of the limit frame 33 to prevent it from being displaced. At the same time, it is also convenient for the user to disassemble it individually later to clean or maintain its inner structure. Due to the existence of the first clamping block 12, it is convenient to insert the second clamping block 13 into the circular groove 10. The second clamping block 13 is adjusted to a point that is not corresponding to the second clamping groove 9, so that the shell cover 5 can be effectively clamped. The clamping of the retaining spring 11 can secondary improve the stability of the clamping of the second clamping block 13 to prevent it from being displaced. The insertion of the positioning block 6 While limiting the position of the shell cover 5, the insertion accuracy of the first card block 12 can also be effectively improved. When it needs to be disassembled later, the second card block 13 is rotated to the point corresponding to the second card slot 9, and then the first card block 12 is directly pulled out, and finally the positioning block 6 is pulled out of the positioning slot 3. While facilitating the later disassembly and assembly of the shell cover 5, it is also more conducive to the user to check or maintain the inner structure of the protective shell 1 later. Due to the existence of the first sealing ring 4, the first sealing ring 4 can effectively seal the connection point between the protective shell 1 and the shell cover 5, thereby effectively improving the sealing effect of the overall protective shell 1, so as to improve the sealing and dustproof performance of the overall shell. Due to the opening of the rectangular opening 19, the user can do it without opening the shell cover 5.The inner side of the protective housing 1 can be viewed directly through the transparent glass 20, which helps the user to observe the operating status of the sensor body 2 at all times, thereby improving the safety protection of the sensor body 2.

Claims

1. A non-contact photoelectric liquid level sensor, characterized in that: It includes a protective shell, a sensor body is installed at the bottom inner end of the protective shell, a shell cover is clamped at the top of the protective shell, the shell cover covers the top of the protective shell, a light input indicator light is installed at the top of the shell cover, a wire is provided at the top of the shell cover, a switching switch is provided at the top of the shell cover, a limiting groove is provided on one side of the protective shell, a vent is provided on one side of the limiting groove, the vent is communicated with the inner side of the protective shell, a filter plate is slidably connected to the inner wall of the vent, the filter plate covers the inner side of the vent, a limiting frame is inserted on one side of the limiting groove, a first dustproof plate and a second dustproof plate are fixedly connected to the inner side of the limiting frame, the position of the second dustproof plate corresponds to the position of the filter plate, a sealing plate is slidably connected to the inner wall of the protective shell, a second protrusion is fixedly connected to the other side of the sealing plate, and the sealing plate covers the other side of the vent.

2. A non-contact photoelectric liquid level sensor according to claim 1, characterized in that: A first slide groove matching the filter plate is provided on the inner wall of the vent, and the filter plate is slidably connected to the inner wall of the vent via the first slide groove. A second slide groove matching the sealing plate is provided on the inner wall of the protective shell, and the sealing plate is slidably connected to the inner wall of the protective shell via the second slide groove.

3. A non-contact photoelectric liquid level sensor according to claim 1, characterized in that: A first groove is provided at the inner bottom end of the vent, a magnet is fixedly connected to the inner bottom end of the first groove, the magnet covers the inner side of the first groove, the bottom end of the filter plate is attached to the top end of the magnet, and the bottom end of the filter plate is made of magnetically attractive material.

4. A non-contact photoelectric liquid level sensor according to claim 1, characterized in that: A second groove is formed on the inner wall of the protective shell, a second sealing ring is fixedly connected to the inner side of the second groove, the second sealing ring covers the inner side of the second groove, and the other side of the second sealing ring is in contact with one side of the sealing plate.

5. The non-contact photoelectric liquid level sensor according to claim 1, characterized in that: A slot is provided on one side of the limit groove, and an insert block matching the slot is fixedly connected to the other side of the limit frame. The insert block is fixedly connected to the four sides of the other side of the limit frame near the corner, and the insert block is inserted into the inner side of the slot. The limit frame is inserted into one side of the limit groove through the slot and the insert block.

6. A non-contact photoelectric liquid level sensor according to claim 1, characterized in that: A positioning groove is provided at the top of the protective shell, and a positioning block matching the positioning groove is fixedly connected to the bottom of the shell cover. The positioning block is fixedly connected to the four sides of the bottom of the shell cover near the corners, and the positioning block is clamped on the inner side of the positioning groove.

7. The non-contact photoelectric liquid level sensor according to claim 1, characterized in that: A first card slot is provided at the top of the shell cover, the first card slot extends to the inside of the protective shell, a second card slot is provided on the inner wall of the first card slot, a circular groove is provided at the inner bottom end of the first card slot, a first card block is clamped on the inner side of the first card slot, a second card block matching the second card slot is fixedly connected to the outer side of the first card block, and the second card block is clamped on the inner side of the circular groove.

8. The non-contact photoelectric liquid level sensor according to claim 7, characterized in that: A retaining spring matching the second clamping block is installed at the inner bottom end of the circular groove, the top of the retaining spring is clamped at the bottom end of the second clamping block, the second clamping block is clamped to the inner side of the circular groove through the retaining spring, the top of the first clamping block is fixedly connected to a sealing block, the sealing block covers the top of the first clamping groove, the top of the sealing block is fixedly connected to a first protrusion, and the shape of the corner of the first protrusion is arc-shaped.

9. The non-contact photoelectric liquid level sensor according to claim 7, characterized in that: A first sealing ring is fixedly connected to the top of the protective shell, and the first sealing ring is located close to the inner side of the first clamping block. A sealing groove matching the first sealing ring is formed at the bottom end of the shell cover, and the first sealing ring covers the inner side of the sealing groove.

10. The non-contact photoelectric liquid level sensor according to claim 1, characterized in that: A rectangular opening is provided on the front side of the protective shell, the rectangular opening is communicated with the inner side of the protective shell, and a transparent glass is fixedly connected to the inner side of the rectangular opening, and the transparent glass covers the inner side of the rectangular opening.

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