A miniature liquid level switch

Abstract

The application provides a micro liquid level switch and belongs to the technical field of liquid level switches. The micro liquid level switch comprises a rod-shaped body, the middle part of the body is provided with a universal clamping part, the two ends of the universal clamping part are respectively provided with a guide pipe and a connecting pipe, a dry reed pipe is inserted in the body, a sleeve pipe is detachably connected to the guide pipe, the middle part of the sleeve pipe is provided with a magnetic assembly capable of triggering the dry reed pipe to be turned on, a floating ball located in the sleeve pipe is slidably connected to the guide pipe, and a magnetic shielding layer in the shape of a cylinder is arranged on the floating ball and surrounds the outer circumferential surface of the guide pipe; when the magnetic shielding layer is located inside the magnetic assembly, the dry reed pipe is turned off; the sleeve pipe is provided with a water passing structure penetrating the inside and outside of the sleeve pipe. The application has the advantages of small size and high reliability.

Description

Technical Field

[0001] This invention belongs to the field of liquid level switch technology and relates to a miniature liquid level switch. Background Technology

[0002] A typical float-type level switch generally includes a switch body with a guide rod, a reed switch built into the switch body, a float that slides on the guide rod, and a magnetic ring embedded in the float. By sliding the float on the guide rod as the liquid level changes, the magnetic ring is driven to contact the reed switch when it is outside the reed switch contact, thus sending out a corresponding liquid level signal. This type of level switch is widely used, has a simple structure, and is relatively inexpensive. However, it also has many drawbacks, such as: detection accuracy is greatly affected by the environment, maintenance cycle is short, and size is relatively large.

[0003] As is well known, level switches operate with high precision in static liquid environments. However, in reality, most level switches are used in environments with fluctuating liquid surfaces. These fluctuations cause the float to move, triggering the switch contacts and transmitting inaccurate level information. Solving this problem typically requires a bypass pipe connected to a leveling tank. The level switch is then placed vertically inside the tank. Figure 6 As shown, this greatly complicates the structure of the liquid container and is not applicable in many cases, limiting the applicable scenarios for this type of float level switch.

[0004] Furthermore, the float of this type of float level switch has a magnetic ring embedded inside. The magnetic ring is a relatively dense object. In order to make the overall density of the float with the embedded magnetic ring significantly lower than the density of the liquid (usually water), the volume of the foamed material float needs to be large enough to balance the influence of the magnetic ring on the overall density of the float. As a result, the volume of the entire float level switch will increase significantly. In addition, embedding a magnetic ring inside the float will increase the overall defect rate of the float (the float with the embedded magnetic ring as a whole). Installing the magnetic ring inside the float also increases the production cost, and the installation process is also more complicated.

[0005] Furthermore, in existing float level switches, in order to protect the float, the float is usually wrapped with a hard material, such as metal. This increases the overall mass of the float structure and requires a larger volume of foam material to balance the overall density of the float, which also increases the overall size of the float level switch.

[0006] Furthermore, since the magnetic ring is located on the outside of the guide rod, magnetic materials in the liquid accumulate on the inner wall of the magnetic ring. Over time, this increases the sliding resistance between the magnetic ring and the guide rod, causing the float level switch to malfunction and requiring cleaning and maintenance. Moreover, in order to reduce the size of the magnetic ring, sufficient magnetic force is needed to trigger the reed switch contacts. The gap between the float and the guide rod is generally very small, which further increases the probability of the float getting stuck due to the magnetic ring adsorbing magnetic powder materials. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned problems in existing technologies by providing a miniature liquid level switch. The technical problem this invention aims to solve is how to reduce the size of the liquid level switch and improve its reliability.

[0008] The objective of this invention can be achieved through the following technical solution: a miniature liquid level switch, comprising a rod-shaped body, a universal clamping part in the middle of the body, a guide tube and a connecting tube at both ends of the universal clamping part, and a reed switch inserted into the body, characterized in that a sleeve is detachably connected to the guide tube, the middle of the sleeve has a magnetic component capable of triggering the reed switch to conduct, a float located inside the sleeve is slidably connected to the guide rod, and a cylindrical magnetic shielding layer surrounding the outer circumference of the guide tube is provided on the float; when the magnetic shielding layer is located inside the magnetic component, the reed switch is disconnected; the sleeve has a water-passing structure penetrating the inside and outside of the sleeve.

[0009] Furthermore, the magnetic component is a ring-shaped permanent magnet material fixed to the outer wall of the sleeve or embedded in the sleeve.

[0010] Furthermore, the magnetic component is an electromagnetic structure fixed to the outer wall of the sleeve or embedded in the sleeve.

[0011] Furthermore, the water-passing structure includes a plurality of water-passing holes formed on the sleeve, the water-passing holes being distributed on both sides of the magnetic component.

[0012] Furthermore, the water-passing structure includes two water-passing pipes, which are located on both sides of the magnetic component.

[0013] Furthermore, the guide tube and the sleeve are threaded together.

[0014] Furthermore, the opening of the sleeve is rotatably connected to a clamping head adapted to a universal clamping part.

[0015] Furthermore, the guide tube has a tapered structure, with the large-diameter end of the guide tube being far from the universal clamping part, and the central perforation of the float being a tapered hole adapted to the guide tube.

[0016] Furthermore, the magnetic shielding layer is located on the inner wall of the perforation in the middle of the float.

[0017] Furthermore, the magnetic shielding layer is located on the outer periphery of the float.

[0018] Furthermore, the magnetic shielding layer is embedded inside the float.

[0019] In this solution, since the magnetic material no longer needs to be fixed to the float, the size of the float can be greatly reduced while still meeting the density requirements, thus significantly reducing the overall size of the liquid level switch.

[0020] Furthermore, the mechanism for triggering the reed switch in this solution differs from that of traditional liquid level switches. In this solution, the magnetic component is always located outside the reed switch contact. However, before the liquid level trigger position, the magnetic field of the magnetic component cannot reach the reed switch due to the magnetic shielding layer on the float, thus preventing the reed switch from being triggered. Only when the float moves up with the liquid level and leaves the inside of the magnetic component, the magnetic component can trigger the reed switch because the magnetic shielding layer is no longer located between the magnetic component and the reed switch.

[0021] This solution uses a sleeve to surround the float, preventing the float from being squeezed by external objects in the environment. In contrast, traditional level switches require a rigid material to protect the float, which increases the volume of the foam material in the float and affects the overall size of the level switch. In other words, the above reasons are one of the reasons why this level switch has a smaller overall size.

[0022] Existing level switches have a magnetic structure located on a float, which needs to reciprocate with the liquid surface. Therefore, existing level switches can only use permanent magnets to trigger reed switches. In this solution, the sleeve is a fixed component, and the magnetic component is separated from the float. The magnetic component can use an electromagnetic structure, and the wires connecting the electromagnetic structure will not interfere with the reciprocating motion of the float. This not only makes the magnetic field strength adjustable and enhances the sensitivity of the level switch, but also allows it to be actively opened or closed, avoiding the adhesion of magnetic materials in the liquid to the level switch.

[0023] Based on the description of the defects of existing level switches in the background technology, it is easy to see that this level switch, because the magnetic material is far away from the guide tube, allows the float to slide more smoothly on the guide tube. The movement of the float will not be affected by the adhesion of magnetic powder on the float, so the sensitivity of this level switch can be maintained for a longer period of time, the maintenance cycle is also greatly extended, and the reliability is improved.

[0024] In addition, to improve the resistance of the level switch to liquid level fluctuations, the guide tube is designed in a conical shape, and the perforation in the middle of the float is also adapted to it. When the liquid level is low, the float moves downwards under its own weight. During the downward movement of the float, the gap between the perforation and the outer wall of the guide tube gradually decreases until the inner wall of the perforation of the float contacts the outer wall of the guide tube, and the two have a certain connection strength. When the liquid level fluctuates slightly, the upward force of the liquid on the float is short and small, and in many cases it is not enough to drive the float to slide on the guide tube. Within a certain range, the influence of liquid level fluctuations on the movement of the float can be eliminated. Only when the liquid level is higher than the float does the float experience a greater buoyancy force, and the float can detach from the contact with the guide tube and move upwards with the liquid level. Therefore, this structure can resist liquid level fluctuations and can be triggered normally. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the liquid level switch in Embodiment 1.

[0026] Figure 2 yes Figure 1 The decomposition diagram in the image.

[0027] Figure 3 This is a schematic diagram of the sleeve structure in Example 2.

[0028] Figure 4 This is a cross-sectional view of the level switch in Embodiment 1.

[0029] Figure 5 This is a schematic diagram of the liquid level switch in Embodiment 3.

[0030] Figure 6 This is a schematic diagram of the placement of a level switch in the prior art to improve its resistance to liquid level fluctuations.

[0031] In the diagram, 1. General clamping part; 2. Guide tube; 3. Connecting tube; 4. Reed switch; 5. Sleeve; 6. Magnetic component; 7. Float; 8. Magnetic shielding layer; 9. Water inlet hole; 10. Water inlet pipe; 11. Clamping head. Detailed Implementation

[0032] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0033] Example 1

[0034] like Figure 1 , Figure 2 and Figure 4As shown, the miniature liquid level switch includes a rod-shaped body with a universal clamping part 1 in the middle. The universal clamping part 1 has a guide tube 2 and a connecting tube 3 at its two ends. A reed switch 4 is inserted into the body. A sleeve 5 is detachably connected to the guide tube 2. The sleeve 5 has a magnetic component 6 in the middle that can trigger the reed switch 4 to conduct. A float 7 located inside the sleeve 5 is slidably connected to the guide rod. A cylindrical magnetic shielding layer 8 is provided on the float 7, which surrounds the outer periphery of the guide tube 2. When the magnetic shielding layer 8 is located inside the magnetic component 6, the reed switch 4 is disconnected. The sleeve 5 has a water-passing structure that penetrates the inside and outside of the sleeve 5.

[0035] The magnetic component 6 is a ring-shaped permanent magnet material fixed to the outer wall of the sleeve 5 or embedded in the sleeve 5.

[0036] Alternatively, the magnetic component 6 can also be an electromagnetic structure fixed to the outer wall of the sleeve 5 or embedded within the sleeve 5. The electromagnetic structure is a structure in which a current-carrying wire is wound around the armature, and this current-carrying wire is connected to an external power supply.

[0037] The water passage structure includes several water passage holes 9 formed on the sleeve 5, which are distributed on both sides of the magnetic component 6. There is a certain gap between the outer wall of the float 7 and the inner wall of the sleeve 5, and the water passage holes 9 are relatively large to prevent dirt from being unable to drain.

[0038] The guide tube 2 and the sleeve 5 are threaded together.

[0039] The opening of the sleeve 5 is rotatably connected to a clamping head 11 that is compatible with the universal clamping part 1.

[0040] The magnetic shielding layer 8 can be attached to the float 7 in the following ways: the magnetic shielding layer 8 is located on the inner wall of the perforation in the middle of the float 7; the magnetic shielding layer 8 is located on the outer circumference of the float 7; or the magnetic shielding layer 8 is embedded in the float 7.

[0041] Example 2

[0042] like Figure 3 As shown, the content of this embodiment is largely the same as that of Embodiment 1, except that the water-passing structure includes two water-passing pipes 10, which are located on both sides of the magnetic component 6. A filter screen is installed inside the water-passing pipe 10 located at the lower end of the magnetic component 6 to prevent large-diameter debris from entering the sleeve 5. This method can better resist liquid level fluctuations and make the liquid inside the sleeve less affected by external liquid level fluctuations.

[0043] Example 3

[0044] like Figure 5As shown, the guide tube 2 has a tapered structure and is detachably connected to the universal clamping part 1. The large-diameter end of the guide tube 2 is far away from the universal clamping part 1, and the central perforation of the float 7 is a tapered hole adapted to the guide tube 2. To improve the resistance of the level switch to liquid level fluctuations, the guide tube 2 is designed in a conical shape, and the perforation in the middle of the float 7 is also adapted to it. When the liquid level is low, the float 7 moves downward under its own weight. During the downward movement of the float 7, the gap between the perforation and the outer wall of the guide tube 2 gradually decreases until the inner wall of the perforation of the float 7 contacts the outer wall of the guide tube 2, and the two have a certain connection strength. When the liquid level fluctuates slightly, the upward force of the liquid on the float 7 is short and small, and in many cases it is not enough to drive the float 7 to slide on the guide tube 2. Within a certain range, the influence of liquid level fluctuations on the movement of the float 7 can be eliminated. Only when the liquid level is higher than the float 7, the float 7 is subjected to a larger buoyancy force, and the float can detach from the contact with the guide tube 2 and then move upward with the liquid level. Therefore, this structure can resist liquid level fluctuations and can be triggered normally.

[0045] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A miniature liquid level switch, comprising a rod-shaped body, wherein the middle portion of the body has a universal clamping part (1), and the two ends of the universal clamping part (1) respectively have guide tubes (2) and connecting tubes (3), and a reed switch (4) is inserted into the body, characterized in that, A sleeve (5) is detachably connected to the guide tube (2). The middle part of the sleeve (5) has a magnetic component (6) that can trigger the reed switch (4) to conduct. A float (7) located inside the sleeve (5) is slidably connected to the guide tube. A cylindrical magnetic shielding layer (8) surrounding the outer circumference of the guide tube (2) is provided on the float (7). When the magnetic shielding layer (8) is located inside the magnetic component (6), the reed switch (4) is disconnected. The sleeve (5) has a water-passing structure that penetrates the inside and outside of the sleeve (5).

2. The miniature liquid level switch according to claim 1, characterized in that, The magnetic component (6) is a ring-shaped permanent magnet material fixed to the outer wall of the sleeve (5) or embedded in the sleeve (5).

3. The miniature liquid level switch according to claim 1, characterized in that, The magnetic component (6) is an electromagnetic structure fixed to the outer wall of the sleeve (5) or embedded in the sleeve (5).

4. A miniature liquid level switch according to claim 1, 2, or 3, characterized in that, The water passage structure includes several water passage holes (9) opened on the sleeve (5), and the water passage holes (9) are distributed on both sides of the magnetic component (6).

5. A miniature liquid level switch according to claim 1, 2, or 3, characterized in that, The water-passing structure includes two water-passing pipes (10), which are located on both sides of the magnetic component (6).

6. A miniature liquid level switch according to claim 1, 2, or 3, characterized in that, The guide tube (2) and the sleeve (5) are threaded together.

7. A miniature liquid level switch according to claim 6, characterized in that, The opening of the sleeve (5) is rotatably connected to a chuck (11) adapted to the universal clamping part (1).

8. A miniature liquid level switch according to claim 1, 2, or 3, characterized in that, The guide tube (2) has a tapered structure, and the large-diameter end of the guide tube (2) is far away from the universal clamping part (1). The middle perforation of the float (7) is a tapered hole adapted to the guide tube (2).

9. A miniature liquid level switch according to claim 1, 2, or 3, characterized in that, The magnetic shielding layer (8) is located on the inner wall of the perforation in the middle of the float (7).

10. A miniature liquid level switch according to claim 1, 2, or 3, characterized in that, The magnetic shielding layer (8) is located on the outer periphery of the float (7).

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