High-precision photoelectric liquid level switch

Abstract

The utility model belongs to the technical field of liquid level sensor, concretely relates to a high accuracy photoelectric liquid level switch, include: detection head, it includes metal seat and the glass prism of sintering in metal seat top, photoelectric monitoring part is connected with detection head through screw thread, connecting line is connected with photoelectric monitoring part terminal, the utility model simple structure has improved the detection accuracy of photoelectric liquid level switch through special technology, has guaranteed the stability of photoelectric liquid level switch in the detection process, and can effectively prevent the corrosion and damage of different medium to the device.

Description

Technical Field

[0001] This utility model belongs to the field of liquid level sensor technology, and in particular relates to a high-precision photoelectric liquid level switch. Background Technology

[0002] Photoelectric level switches primarily utilize the principles of light reflection and refraction for detection. Infrared light emitted from a diode is reflected by a prism at the sensor. When the prism is in the air, the light signal is reflected back to the sensor and received by the photodetector. The reflection and refraction paths of light differ on different surfaces. If liquid submerges the prism, the light signal weakens as it passes through the liquid-covered prism, resulting in a reduced light intensity received by the photodetector, which then emits a low-level signal.

[0003] Existing photoelectric liquid level switches have certain liquid level detection functions, but after long-term use, dirt (such as impurities and oil stains) on the sensor surface may cover the detection surface, leading to signal attenuation or false alarms, requiring regular cleaning and maintenance. At the same time, in high-viscosity liquids, liquids containing suspended solids, liquids that are prone to crystallization, or liquids that are highly corrosive may cause signal drift or damage to the glass probe, thereby affecting its detection and feedback accuracy. Utility Model Content

[0004] The purpose of this utility model is to provide a high-precision photoelectric liquid level switch, comprising: The detection head includes a metal base and a glass prism sintered at the top of the metal base; A photoelectric monitoring component, which is connected to the detection head via threads; A connecting line is connected to the end of the photoelectric monitoring component.

[0005] Preferably, the top of the metal base is provided with a cylindrical prism base, and the transition between the cylindrical prism base and the metal base is an arc shape with R≥3mm.

[0006] Preferably, the glass prism has a conical structure and is made of [material name missing]. The doped GBS glass is sintered and fused together with the conveyed cylindrical prism holder.

[0007] Preferably, the detection head is hollow inside, and the rear end is integrally formed with a connecting section with threads on the surface.

[0008] Preferably, the photoelectric monitoring component includes a metal housing, and a detection unit is installed inside the metal housing. The detection unit integrates an infrared light-emitting diode and a photoelectric receiver.

[0009] Preferably, the metal casing has mounting threads on its inner side.

[0010] Preferably, the connecting wire extends into the interior of the metal casing and is connected to the infrared light-emitting diode and the photodetector.

[0011] The beneficial effects of this utility model are: By employing an aspherical conical GBS prism in conjunction with a pulsed modulated light source (10kHz) and a synchronous detection circuit, a detection accuracy of ±0.5mm is achieved, which is three times higher than that of traditional photoelectric level switches, significantly improving its accuracy and reliability. The ≥3mm radius arc transition design between the metal base and the prism base disperses 90% of edge stress, reducing stress concentration. The surface of the doped GBS glass is not prone to dirt adhesion and can effectively reduce the corrosion rate of acidic and alkaline liquids (pH 2~12), thus ensuring the detection accuracy of the glass prism while effectively extending its service life.

[0012] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0013] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this utility model; Figure 2 The difference is in the embodiments of this utility model. GBS-doped glass forming region; Figure 3 The difference is in the embodiments of this utility model. A schematic diagram of the DSC curve of GBS-doped glass.

[0015] In the picture: Detection head 1, metal base 2, glass prism 3, photoelectric monitoring component 4, connecting line 5, cylindrical prism base 6, boss transition 7, connecting section 8, metal shell 9, detection unit 10, infrared light-emitting diode 11, photoelectric receiver 12. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] like Figures 1 to 3 As shown, this embodiment provides a high-precision photoelectric liquid level switch, including: a detection head 1, which includes a metal base 2 and a glass prism 3 sintered at the top of the metal base 2. The metal base 2 is made of 316L stainless steel, and its yield strength is increased by 40% after cold rolling strengthening treatment to ensure structural stability in a wide temperature range of -40~250℃; a photoelectric monitoring component 4, which is connected to the detection head 1 by threads; and a connecting line 5, which is connected to the end of the photoelectric monitoring component 4. A cylindrical prism seat 6 is provided on the top of the metal seat 2. The boss transition 7 between the cylindrical prism seat 6 and the metal seat 2 is an arc with a radius of R=3mm. According to mechanical design theory, when the radius of the arc R ≥ the wall thickness H / 4, the effective stress concentration factor is <2. If R increases to H / 2, the factor can be reduced to 1.5. Here, the wall thickness of the metal seat 2 is 3mm, so the arc with a radius of R=3mm can avoid crack initiation and extend the fatigue life of the parts. Therefore, this arc can disperse more than 90% of the edge stress, reduce the internal stress to 4MPa, and withstand the impact of large flow and force on the cylindrical prism seat 6, preventing the cylindrical prism seat 6 from breaking under long-term use.

[0018] The glass prism 3 has a conical structure and is made of [material name missing]. The doped GBS glass is sintered and fused together with the conveyed cylindrical prism holder 6; specifically, 30% should be selected. GBS glass with added dopant.

[0019] The detection head 1 is hollow inside, with a threaded connecting section 8 integrally formed at the rear end. The photoelectric monitoring component 4 includes a metal housing 9, inside which a detection unit 10 is installed. The detection unit 10 integrates an infrared light-emitting diode 11 and a photodetector 12. The infrared light-emitting diode 11 emits light as a pulse-modulated light source (10kHz), which is reflected by the inside of a conical glass prism 3 to the photodetector 12 and the synchronous detection circuit. The liquid level height at the glass prism 3 is determined by the attenuation of the light received by the photodetector 12. The metal housing 9 has mounting threads on its inner side, allowing the connecting section 8 of the detection head 1 and the photoelectric monitoring component 4 to be screwed together. The connecting wire 5 extends into the metal housing 9 and communicates with the infrared light-emitting diode 11 and the photodetector 12.

[0020] In this application, the glass prism 3 is selected as 30%. The specific preparation steps for doped GBS glass are as follows: 1. Raw material ratio: 30wt% pure terbium oxide (Tb4O7), 40wt% boric acid (H3BO3), 15wt% gallium oxide (Ga2O3), and 15wt% silicon oxide (SiO2); 2. Melting process: A two-step melting method is adopted. First, the mixture is kept at 650℃ for 3 hours, then added to a platinum crucible at 1400℃ and kept at 1450℃ for 2 hours, and finally poured into a preheated iron mold. 3. Annealing treatment: After holding at 750℃ in a muffle furnace for 30 minutes, the temperature is reduced to 200℃ at a rate of 1℃ / h, and the furnace is closed and allowed to cool naturally to room temperature; 4. Sintering process: The GBS glass prism and the metal prism base are fused together in a vacuum sintering furnace at 1100℃ to form a seamless integrated structure, ensuring that there are no air gaps at the optical interface.

[0021] The difficulty in its preparation process lies in the GBS glass. The determination of the dosage varies depending on the specific circumstances. The properties of GBS-doped glasses vary greatly, therefore it is necessary to study different... The performance of GBS-doped glasses was tested and compared: like Figure 2 As shown, the GBS glass-forming region follows The dosage increases first and then decreases with increasing dosage. The maximum glass-forming area is achieved at 30%. This is mainly due to... Caused by a dual effect, It acts as a network in the glass structure, providing free oxygen ions. With With increasing doping concentration, the number of free oxygen ions in the glass also increases, and the two-dimensional boron-oxygen triangular ions in the random glass network structure gradually transform into three-dimensional boron-oxygen tetrahedra, making the network structure more stable; and Filling the gaps in the network structure continuously increases the density of the glass. Improvements in the glass network structure lead to an expansion of the glass-forming area. If... When the doping amount exceeds the maximum capacity of the glass network, at this point... The damage to the glass structure gradually intensifies, causing the bonds in the glass to break and gradually transform into non-bridging oxygen, thus reducing the glass density; and The strong accumulation process leads to a gradual decrease in glass stability and a reduction in glass-forming ability.

[0022] like Figure 3 As shown, different The stability of GBS-doped glass is measured by the crystallization parameter β. A larger β indicates a more stable glass; a smaller β indicates a glass that is more prone to crystallization. The value of β is calculated as follows: , In the formula, This refers to the GBS glass transition temperature. This refers to the crystallization temperature of GBS glass. This is the melting temperature of GBS glass.

[0023] Depend on Figure 3 It can be seen that, with With increasing doping concentration, β first increases and then decreases, reaching a maximum at 30%. The maximum value is achieved at this time. This is because, from a network structure perspective, B atoms and M (Al and Ga) atoms in oxide glasses can... and as well as and It exists in the form of [something]. When there is excess free oxygen present... and Acceptable conversion of free oxygen into and The glass network structure is strengthened, increasing stability; however, due to and Negatively charged, they cannot be directly connected and must be separated by other coordination polyhedral groups (such as silicon oxide). and Towards and The transformation is limited, therefore adding excessive amounts... At that time, the density of the glass network structure decreases, and its stability weakens.

[0024] In conclusion, 30% should be selected. When glass prisms 3 are made with GBS glass with added additives, their stability, corrosion resistance, and dirt adhesion are significantly improved, thereby ensuring the high precision performance of the photoelectric level switch in different media and effectively extending its service life.

[0025] All the devices selected in this application (parts whose specific structures are not specified) are general standard parts or parts known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0026] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high-precision photoelectric liquid level switch, characterized in that, include: The detection head (1) includes a metal base (2) and a glass prism (3) sintered at the top of the metal base (2). The photoelectric monitoring component (4) is connected to the detection head (1) by a thread; The connecting line (5) is connected to the end of the photoelectric monitoring component (4).

2. The high-precision photoelectric liquid level switch according to claim 1, characterized in that: The top of the metal base (2) is provided with a cylindrical prism base (6), and the boss transition (7) between the cylindrical prism base (6) and the metal base (2) is an arc shape with R≥3mm.

3. The high-precision photoelectric liquid level switch according to claim 2, characterized in that: The glass prism (3) has a conical structure and is made of [material name missing]. The doped GBS glass is sintered and fused together with the cylindrical prism holder (6) being transported.

4. The high-precision photoelectric liquid level switch according to claim 3, characterized in that: The detection head (1) is hollow inside, and the rear end is integrally formed with a connecting section (8) with threads on the surface.

5. The high-precision photoelectric liquid level switch according to claim 1, characterized in that: The photoelectric monitoring component (4) includes a metal casing (9), and a detection unit (10) is installed inside the metal casing (9). The detection unit (10) integrates an infrared light-emitting diode (11) and a photoelectric receiver (12).

6. The high-precision photoelectric liquid level switch according to claim 5, characterized in that: The metal casing (9) has mounting threads on its inner side.

7. The high-precision photoelectric liquid level switch according to claim 6, characterized in that: The connecting line (5) extends into the interior of the metal casing (9) and is connected to the infrared light-emitting diode (11) and the photodetector (12).

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