A liquid level sensor

Abstract

The utility model discloses a liquid level sensor belongs to liquid level sensor technical field. Including the shell, the shell lower extreme is installed with the insulating sleeve pipe, is provided with the induction electrode stem in the insulating sleeve pipe, is provided with the mounting portion to the shell lower extreme, and the shell bottom is located the outside of mounting portion and is provided with the sealing assembly, the sealing assembly includes the U type mounting ring, and the shell bottom surface is provided with the installation groove, and the U type mounting ring is installed in the installation groove, and the U type mounting ring is opposite and is provided with two sealing strips in, and is provided with the sealing ring between two sealing strips, and the inboard of sealing strip is provided with a plurality of elastic parts. The utility model discloses through multilayer sealing piece and elastic pre -tightening structure, can adapt to the vehicle -mounted vibration environment, and continuously provide the close -fitting pressure for sealing ring, effectively block the fuel leakage path, and adapt the sealing demand of complex installation scene. The mounting portion guarantees the assembly concentricity of insulating sleeve pipe, and the U type mounting ring accurate positioning sealing assembly reduces assembly deviation, improves the structural integrity, also reduces the installation difficulty.

Description

Technical Field

[0001] This utility model relates to the field of liquid level sensor technology, and more specifically, to a liquid level sensor. Background Technology

[0002] Capacitive fuel level sensors are core components for monitoring fuel tank levels in commercial vehicles, construction machinery, and other equipment. Their performance directly affects the accuracy of fuel metering and the safety of equipment operation. However, existing sensors of this type still have several technical shortcomings under complex on-board conditions: Regarding sealing performance, existing products mostly employ a simple sealing structure with a single O-ring, lacking an elastic pre-tightening mechanism. Continuous bumps and vibrations in the vehicle environment can easily lead to a decrease in the sealing pressure, especially when there is fuel vapor pressure in the fuel tank. The sealing gap will widen with vibration, not only easily causing fuel leakage but also allowing external moisture and dust to enter the sensor, affecting circuit stability and even posing safety hazards. In terms of measurement accuracy, traditional induction electrode rods are mostly made of ordinary stainless steel, which is unsuitable for the corrosive environment of high-sulfur fuel (long-term immersion can easily cause rust on the rod surface, reducing capacitive sensing sensitivity).

[0003] In addition, the existing products have poor structural assembly: the sealing components lack a precise positioning structure, which makes them prone to misalignment during installation. This not only increases the assembly time for workers, but also easily exacerbates the risk of seal failure due to assembly deviations, making it difficult to adapt to the needs of large-scale equipment assembly.

[0004] Therefore, the performance of existing capacitive fuel level sensors is insufficient to meet the high reliability and high accuracy requirements of automotive applications, necessitating targeted structural improvements. In light of this, we propose a new fuel level sensor. Utility Model Content

[0005] The purpose of this invention is to provide a liquid level sensor to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A liquid level sensor includes a housing, an insulating outer sleeve installed at the lower end of the housing, a sensing electrode rod disposed inside the insulating outer sleeve, a mounting part disposed at the lower end of the housing, an upper end of the insulating outer sleeve connected to the mounting part, and a sealing component disposed at the bottom of the housing outside the mounting part. The sealing assembly includes a U-shaped mounting ring. A mounting groove is provided on the bottom surface of the housing. The U-shaped mounting ring is installed in the mounting groove. Two sealing strips are arranged opposite each other inside the U-shaped mounting ring. A sealing ring is provided between the two sealing strips. Multiple elastic elements are provided inside the sealing strips. The ends of the elastic elements are in contact with the surface of the sealing ring.

[0007] Preferably, the elastic element includes a spring, with a ball connected to the end of the spring, and a groove is provided on the sealing strip, with the spring extending into the groove.

[0008] Preferably, the sealing strip has a bevel at the outer end of the mounting groove.

[0009] Preferably, a connecting cable is provided on one side of the housing, and the end of the connecting cable located inside the housing is configured as a corrugated pipe structure.

[0010] Preferably, a circuit module is provided inside the housing, and the circuit module is electrically connected to the connecting cable. A buffer groove is provided on the inner wall of the housing at the location of the connecting cable, and a rubber pad is provided inside the buffer groove.

[0011] Preferably, the outer surface of the sensing electrode rod is coated with an oleophobic and anti-stick coating, and the material of the sensing electrode rod is titanium alloy or 316L stainless steel.

[0012] Preferably, the insulating outer sheath is made of a composite material reinforced with fluororubber and glass fiber.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: (1) This utility model, through multi-layer sealing components and elastic pre-tightening structure, can adapt to the vehicle vibration environment, continuously provide fitting pressure for the sealing ring, effectively block the fuel leakage path, and adapt to the sealing requirements of complex installation scenarios. The mounting part ensures the coaxiality of the insulating outer sleeve assembly, and the U-shaped mounting ring accurately positions the sealing components, reducing assembly deviation, which not only improves the overall structure but also reduces the installation difficulty. The oleophobic and anti-fouling coating of the sensing electrode rod reduces viscous fuel residue, and the titanium alloy / 316L stainless steel material ensures sensing stability, greatly reducing measurement errors caused by wall adhesion and corrosion.

[0014] (2) The corrugated tube of the connecting cable of this utility model buffers the vibration tension and the rubber pad absorbs the impact, reducing the interference of vibration on the connection, sealing and signal transmission of the components and improving the adaptability of the working conditions. The fluororubber and glass fiber composite material of the insulating outer tube and the corrosion-resistant material of the electrode rod enhance the ability of the components to resist fuel corrosion and wear, and extend the overall service life of the sensor. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the outer shell structure of this utility model; Figure 3 This is a schematic diagram of the sealing component structure of this utility model.

[0016] The following are the labels in the diagram: 1. Outer shell; 101. Mounting part; 2. Insulating outer sleeve; 3. Induction electrode rod; 4. U-shaped mounting ring; 5. Sealing strip; 501. Bevel; 6. Sealing ring; 7. Spring; 8. Sphere; 9. Connecting cable; 10. Circuit module; 11. Rubber pad. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0018] Example: Please see Figure 1-3 A liquid level sensor includes a housing 1, an insulating outer sleeve 2 installed at the lower end of the housing 1, a sensing electrode rod 3 disposed inside the insulating outer sleeve 2, a mounting part 101 disposed at the lower end of the housing 1, and the upper end of the insulating outer sleeve 2 connected to the mounting part 101 to ensure the coaxiality and connection stability of the insulating outer sleeve and the housing, and to avoid electrode rod tilting and measurement errors caused by assembly deviations; a sealing assembly is disposed at the bottom of the housing 1 outside the mounting part 101 for sealing the liquid level sensor.

[0019] like Figure 3 As shown, the sealing assembly includes a U-shaped mounting ring 4. A mounting groove is provided on the bottom surface of the housing 1, and the U-shaped mounting ring 4 is installed within the mounting groove, supporting the sealing strip 5 and the sealing ring 6. The U-shaped mounting ring 4 is embedded in the mounting groove 101 of the housing 1 to achieve positioning and installation of the sealing components, preventing displacement of the sealing structure in a vibration environment and improving the structural stability of the sealing system. Two sealing strips 5 are arranged opposite each other inside the U-shaped mounting ring 4, and a sealing ring 6 is positioned between the two sealing strips 5. Multiple elastic elements are provided on the inner side of the sealing strips 5, with the ends of the elastic elements contacting the surface of the sealing ring 6. The elastic elements provide a certain pressure to the sealing ring 6, resulting in a better sealing effect when the sensor is installed.

[0020] The sealing strip 5 has a bevel 501 on the outer end of the mounting groove, which improves the sealing effect. The sealing strip 5, together with the sealing ring 6, forms a multi-layered sealing structure. The inner groove provides installation space for the elastic element; the bevel 501 increases the contact area with the mounting surface (such as a fuel tank), and the bevel design improves the tightness of the sealing surface, reducing gaps; the groove adapts to the elastic element, ensuring effective transmission of elastic pressure and strengthening sealing synergy. The sealing ring 6 directly contacts the surface of the object to be installed (such as a fuel tank) and is the core contact component of the seal; through the continuous pressure of the elastic element, it maintains a tight fit with the mounting surface, blocking fuel leakage paths and improving the sealing reliability of the sensor.

[0021] In this application, the elastic elements are arranged in multiple groups at equal intervals in a ring. The elastic elements include springs 7, with a ball 8 connected to the end of the spring 7. A groove is provided on the sealing strip 5, and the spring 7 extends into the groove. By setting the spring 7 to provide a certain elastic force to the ball 8, the ball 8 squeezes the sealing ring 6 to achieve a sealing effect between the liquid level sensor and the object to be installed.

[0022] Spring 7 provides elastic force, which is evenly transmitted to sealing ring 6 through ball 8, providing continuous pre-tightening pressure to sealing ring 6; it is especially suitable for vehicle vibration environment, and can maintain the contact pressure of sealing ring 6 even if there are slight errors in the mounting surface or it is affected by vibration, thus avoiding seal failure; the design of ball 8 makes the elastic force transmission more uniform and reduces local wear of sealing ring.

[0023] In this application, a connecting cable 9 is provided on one side of the outer casing 1. The inner end of the connecting cable 9 is provided with a corrugated tube structure. The corrugated tube structure is provided to prevent the cable from becoming tense when there is vibration.

[0024] In this application, a circuit module 10 is provided inside the housing 1. The circuit module 10 is electrically connected to the connecting cable 9. A buffer groove is provided on the inner wall of the housing 1 at the location of the connecting cable 9. A rubber pad 11 is provided in the buffer groove. The rubber pad 11 is designed to provide buffer support for the insertion end of the connecting cable 9, absorb vibration energy, prevent the connection between the connecting cable 9 and the housing 1 from loosening due to vibration, improve the stability of the cable connection, and reduce signal transmission failures.

[0025] Connecting cable 9 provides power to circuit module 10 and transmits liquid level signals. The corrugated pipe structure buffers cable tension caused by vibration, preventing cable damage and improving vibration resistance and lifespan. Circuit module 10 receives the capacitance signal from sensing electrode rod 3, converts it into identifiable liquid level data, and outputs the signal through connecting cable 9. Circuit module 10 integrates signal processing functions to achieve accurate conversion and stable transmission of liquid level signals, ensuring the accuracy of measurement data.

[0026] In this application, the outer surface of the sensing electrode rod 3 is coated with an oleophobic and anti-fouling coating, and the material of the sensing electrode rod 3 is titanium alloy or 316L stainless steel. As the core liquid level sensing component, the sensing electrode rod 3 changes its capacitance by varying its contact area with the fuel, thereby acquiring the liquid level signal. The titanium alloy / 316L stainless steel material is resistant to fuel corrosion (especially sulfur-containing fuel) and suitable for long-term immersion environments. The oleophobic and anti-fouling coating reduces the residue of viscous fuel on the rod surface, avoiding liquid level measurement errors caused by adhesion and improving measurement accuracy.

[0027] In this application, the insulating outer sleeve 2 is made of a composite material reinforced with fluororubber and glass fiber. The insulating outer sleeve 2 wraps around the induction electrode rod 3, achieving insulation isolation between the electrode rod and the outside (such as the fuel tank wall) to avoid short circuits; at the same time, it protects the electrode rod from direct erosion and wear by fuel. The use of a composite material reinforced with fluororubber and glass fiber combines fuel corrosion resistance, insulation stability, and wear resistance, ensuring the insulation performance of the electrode rod and extending its working life.

[0028] In this application, the liquid level measurement is as follows: when the fuel level in the tank rises, the contact area between the sensing electrode rod 3 and the fuel increases, and the capacitance value increases linearly. The circuit module 10 collects the capacitance signal, converts it into a standard liquid level signal of 4-20mA, and transmits it to the vehicle instrument panel through the connecting cable 9 to realize the fuel level display.

[0029] Assembly process First, embed the rubber pad 11 into the buffer groove of the outer shell 1, then fix the circuit module 10 in the slot inside the outer shell 1, and insert the corrugated section of the connecting cable 9 through the rubber pad 11 into the groove on the inner wall of the outer shell 1 so that the end of the connecting cable 9 protrudes out of the outer shell 1, and solder the inner end of the connecting cable 9 to the pin of the circuit module 10. Embed the U-shaped mounting ring 4 in the annular mounting groove of the outer shell 1, install the spring 7 and the ball 8 into the groove of the sealing strip 5 in sequence, then symmetrically place the two sealing strips 5 into the U-shaped mounting ring 4, and finally place the sealing ring 6 between the two sealing strips 5 to complete the assembly of the sealing component. Insert the sensing electrode rod 3 into the insulating outer sleeve 2, insert the upper end of the outer sleeve into the mounting part 101 of the outer casing 1, and tighten it with threads to fix it. Finally, the assembled sensor is fixed to the mounting port of the vehicle's fuel tank by the mounting part 101 at the lower end of the housing 1 and the sealing assembly, thus completing the overall assembly.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A liquid level sensor, comprising a housing (1), wherein an insulating outer sleeve (2) is installed at the lower end of the housing (1), and a sensing electrode rod (3) is disposed inside the insulating outer sleeve (2), characterized in that: The lower end of the outer shell (1) is provided with a mounting part (101), the upper end of the insulating outer sleeve (2) is connected to the mounting part (101), and the bottom of the outer shell (1) is provided with a sealing component outside the mounting part (101); The sealing assembly includes a U-shaped mounting ring (4), and the bottom surface of the outer shell (1) is provided with a mounting groove. The U-shaped mounting ring (4) is installed in the mounting groove. Two sealing strips (5) are arranged opposite to each other inside the U-shaped mounting ring (4). A sealing ring (6) is provided between the two sealing strips (5). Multiple elastic elements are provided on the inner side of the sealing strips (5). The ends of the elastic elements are in contact with the surface of the sealing ring (6).

2. A liquid level sensor according to claim 1, characterized in that: The elastic element includes a spring (7), the end of which is connected to a ball (8), and a groove is provided on the sealing strip (5), with the spring (7) extending into the groove.

3. A liquid level sensor according to claim 1, characterized in that: The sealing strip (5) has an inclined surface (501) at the outer end of the mounting groove.

4. A liquid level sensor according to claim 1, characterized in that: A connecting cable (9) is provided on one side of the outer shell (1), and one end of the connecting cable (9) located inside the outer shell (1) is configured as a corrugated pipe structure.

5. A liquid level sensor according to claim 4, characterized in that: The outer casing (1) is provided with a circuit module (10), which is electrically connected to the connecting cable (9). The inner wall of the outer casing (1) located at the connecting cable (9) is provided with a buffer groove, and a rubber pad (11) is provided in the buffer groove.

6. A liquid level sensor according to claim 1, characterized in that: The outer surface of the sensing electrode rod (3) is coated with an oleophobic and anti-stick coating, and the material of the sensing electrode rod (3) is titanium alloy or 316L stainless steel.

7. A liquid level sensor according to claim 1, characterized in that: The insulating outer sheath (2) is made of a composite material reinforced with fluororubber and glass fiber.

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