Low-range high-precision differential pressure sensor core structure

Abstract

The utility model discloses a low-range high-precision differential pressure sensor core body structure, which comprises a glass sintering device and a capacitor core body I. The bottom of the glass sintering device is fixedly connected with a capacitor separation blade, the glass sintering device is fixed at the middle part of a capacitor core body II and is in welded connection with the capacitor core body II, and the capacitor core body II is provided with a gas guide tube I; a diaphragm is arranged at the bottom of the second capacitor core body, a first capacitor core body is arranged on the side, away from the second capacitor core body, of the diaphragm, and a second air guide pipe is arranged on the first capacitor core body. According to the utility model, the capacitance principle is adopted to measure the pressure, the larger the pressure sensing surface of the capacitor core body is, the smaller the measuring range is, only part size control is needed, the processing is simple, and the qualified rate is high.

Description

Technical Field

[0001] The utility model relates to the technical field of sensor core structures, in particular to a low-range high-precision differential pressure sensor core structure. Background Art

[0002] With the rapid development, more industries have increasing requirements for the environment. For example, the breeding industry needs to ensure that the indoor environment is at positive pressure to ensure the elimination of bacteria; medical operating rooms need to maintain positive pressure at all times and exhaust the indoor air to prevent dust and bacteria from entering the room and affecting the operating room environment; the dust-free workshops in the electronics industry also need to maintain a positive pressure environment at all times and exhaust air to ensure product quality.

[0003] Therefore, the demand for differential pressure sensors is also increasing. When used in the above environment, the existing differential pressure cores are all silicon piezoresistive differential pressure core structures, with a large range and low accuracy below 1KPa. They cannot be measured very accurately and are not suitable for customer needs. Utility Model Content

[0004] The purpose of the present invention is to provide a low-range high-precision differential pressure sensor core structure to address the deficiencies of the prior art and to solve the problems raised in the background art.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a low-range, high-precision differential pressure sensor core structure, comprising a glass sinter and a capacitor core one, the bottom of the glass sinter is fixedly connected to the capacitor baffle, the glass sinter is fixed to the middle of the capacitor core two and welded to it, an air guide tube one is provided on the capacitor core two, a diaphragm is provided at the bottom of the capacitor core two, the capacitor core one is provided on the side of the diaphragm away from the capacitor core two, and an air guide tube two is provided on the capacitor core one.

[0006] Preferably, the diaphragm is a flexible metal diaphragm.

[0007] Preferably, an air outlet is provided at the bottom of the second capacitor core, and a cavity is provided between the bottom of the second capacitor core and the diaphragm.

[0008] Preferably, an air outlet is provided on the upper side of the capacitor core 1, and a cavity is provided between the upper side of the capacitor core 1 and the diaphragm.

[0009] Compared with the existing technology, the utility model provides a low-range, high-precision differential pressure sensor core structure with the following beneficial effects: the traditional silicon piezoresistive differential pressure core relies on a silicon crystal source to measure pressure. The thickness of the silicon crystal source determines the range. The thinner the silicon crystal source, the smaller the range. However, due to limitations in the manufacturing process, the minimum can only be around 1KPa, and the scrap rate is high. The utility model uses the capacitive principle to measure pressure. The larger the pressure-sensing surface of the capacitor core, the smaller the range can be. Only part size control is required, processing is simple, and the qualified rate is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a structural diagram of a low-range, high-precision differential pressure sensor core structure proposed by the utility model;

[0011] Figure 2 A schematic diagram of the internal structure of a low-range, high-precision differential pressure sensor core structure proposed by the present invention;

[0012] Figure 3 This is a diagram showing the parameter significance of the core structure of a low-range, high-precision differential pressure sensor proposed in this utility model.

[0013] Figure numerals: 1. glass sinter; 2. capacitor core 2; 3. gas guide tube 1; 4. capacitor core 1; 5. capacitor baffle; 6. diaphragm; 7. gas guide tube 2. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] A low-range high-precision differential pressure sensor core structure is as follows Figure 1 and Figure 2 As shown, the capacitor baffle 5 is fixed on the glass sintered connector 1, the glass sintered connector 1 is welded and fixed on the capacitor core 2, an air guide tube 3 is provided on the capacitor core 2, and an air guide tube 2 7 is also provided on the capacitor core 1 4. A diaphragm 6 is provided between the capacitor core 2 2 and the capacitor core 1 4, and the diaphragm 6 divides the capacitor core into two upper and lower cavities.

[0016] Capacitor core 2 2, capacitor core 1 4 and diaphragm 6 constitute electrode 1, and capacitor baffle 5 and sintered connector 1 constitute electrode 2. When pressure is added from air duct 1 3 at the end of capacitor core 2, the distance between capacitor baffle 5 and diaphragm 6 increases, and the capacitance value of the core increases. When pressure is added from air duct 2 7 at the end of capacitor core 1 4, the distance between capacitor baffle 5 and diaphragm 6 decreases, and the capacitance value of the core decreases. The pressure is measured based on the capacitance value.

[0017] Due to the limitations of the conventional silicon piezoresistive differential pressure core structure, the minimum core range is 1KPa. Below 1KPa, the accuracy is very poor and inaccurate. This patent is a low-range, high-precision differential pressure sensor core structure. By increasing the pressure-bearing area by enlarging the core cavity, it can measure a pressure of 100Pa. Because the pressure-bearing area is large and the pressure sensing is sensitive, the accuracy of the differential pressure core is greatly improved.

[0018] According to a large amount of experimental data, it is found that the core sensitivity is proportional to the electrode plate area S, and the core sensitivity is inversely proportional to the electrode plate distance P. Figure 3 As shown, when the radius of the capacitor baffle 5 is 6 mm and the distance between the capacitor baffle 5 and the diaphragm 6 is 0.5 mm, the core can actually measure 100 Pa. According to the above experiment, when the radius of the capacitor baffle 5 is increased or the distance between the capacitor baffle 5 and the diaphragm 6 is reduced, the sensitivity of the differential pressure sensor can be greater and the range can be smaller.

[0019] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A low-range high-precision differential pressure sensor core structure, characterized in that: The invention comprises a glass sinter (1) and a capacitor core body 1 (4), wherein the bottom of the glass sinter (1) is fixedly connected to a capacitor baffle (5), the glass sinter (1) is fixed to the middle of the capacitor core body 2 (2) and is welded thereto, an air guide tube 1 (3) is provided on the capacitor core body 2 (2), a diaphragm (6) is provided at the bottom of the capacitor core body 2 (2), the capacitor core body 1 (4) is provided on the side of the diaphragm (6) away from the capacitor core body 2 (2), and an air guide tube 2 (7) is provided on the capacitor core body 1 (4).

2. The low-range high-precision differential pressure sensor core structure according to claim 1, characterized in that: The diaphragm (6) is a flexible metal diaphragm.

3. The low-range high-precision differential pressure sensor core structure according to claim 1, characterized in that: An air outlet is provided at the bottom of the second capacitor core (2), and a cavity is provided between the bottom of the second capacitor core (2) and the diaphragm (6).

4. The low-range high-precision differential pressure sensor core structure according to claim 1, characterized in that: An air outlet is provided on the upper side of the capacitor core (4), and a cavity is provided between the upper side of the capacitor core (4) and the diaphragm (6).

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