Double-nozzle type gas differential pressure sensor

Abstract

The utility model relates to the technical field of gas pressure difference detection, in particular to a double-nozzle type gas pressure difference sensor, which comprises a base and a metal cover plate, a circle of mounting groove is arranged on the inner wall of the base, the metal cover plate is mounted on the mounting groove, two air nozzles are arranged on the base, and an air pressure chamber and two air holes are arranged in the base. The air pressure chambers are communicated with the corresponding air taps through air holes, MEMS chips are embedded in the air pressure chambers, resistance strain gauges are arranged on the surfaces of the MEMS chips, the MEMS chips are attached to one air hole, one face of each resistance strain gauge is communicated with the corresponding air tap, and the other face of each resistance strain gauge is in contact with the corresponding air pressure chamber. Communication pins electrically connected with the MEMS chip are arranged on the two sides of the base. According to the utility model, high-precision and high-reliability differential pressure detection is realized through a double-gas-path isolation design, MEMS high-precision sensing, gas nozzle structure reinforcement, reverse connection prevention and heat dissipation optimization, and the differential pressure sensor is particularly suitable for the field of medical equipment.

Description

Technical Field

[0001] This utility model relates to the field of gas differential pressure detection technology, and in particular to a dual-nozzle gas differential pressure sensor. Background Technology

[0002] Gas differential pressure sensors are widely used in medical equipment, such as ventilators and anesthesia machines, to measure the pressure difference between two gas paths or cavities. Existing differential pressure sensors suffer from the following problems: the nozzle structure is easily damaged, and its sealing performance deteriorates after long-term use; the conductive pins are easily reversed, leading to signal reading errors; heat dissipation is poor, and the lifespan of electronic components is affected by heat buildup; the sensor is large in size, has low sensitivity, and exhibits significant zero-point drift. For example, Chinese patent CN 217237067 U discloses a single-nozzle differential pressure sensor, which optimizes nozzle strength and heat dissipation through designs such as a reinforced base, an indicator notch, and a metal cover. However, it is only suitable for measuring the pressure difference between a single gas path and atmospheric pressure and cannot meet the high-precision differential pressure detection requirements of dual gas paths. Therefore, designing a sensor to achieve high-precision synchronous measurement of dual gas paths has become a key technical challenge in this field. Utility Model Content

[0003] The purpose of this invention is to provide a dual-nozzle gas differential pressure sensor to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a dual-nozzle gas differential pressure sensor, comprising a base and a metal cover plate. The inner wall of the base is provided with a mounting groove, and the metal cover plate is mounted on the mounting groove. The base is provided with two gas nozzles. The base has a built-in pressure chamber and two air holes. The pressure chamber is connected to the corresponding gas nozzle through the air holes. A MEMS chip is embedded in the pressure chamber. A resistance strain gauge is provided on the surface of the MEMS chip. The MEMS chip is attached to one of the air holes, and one side of the resistance strain gauge is connected to the gas nozzle, while the other side of the resistance strain gauge is in contact with the pressure chamber. Communication pins electrically connected to the MEMS chip are provided on both sides of the base.

[0005] Preferably, the two air nozzles are air nozzle one and air nozzle two, and both air nozzles have barbed structures at their ends.

[0006] Preferably, the two air holes are air hole one and air hole two, with air hole one connected to air nozzle one and air hole two connected to air nozzle two.

[0007] Preferably, the base is further provided with two annular chambers, namely annular chamber one and annular chamber two. One end of annular chamber one is connected to air hole one and the other end is connected to air nozzle one; annular chamber two is connected to air hole two and the other end is connected to air nozzle two.

[0008] Preferably, the two air nozzles and the base are integrally injection molded with reinforcing ribs.

[0009] Preferably, the base is a cuboid structure, and one side of the base is provided with a directional indicator notch, which points to the first pin of the communication pin.

[0010] Compared with the prior art, this utility model provides a dual-nozzle gas differential pressure sensor with the following advantages: This utility model can achieve high-precision measurement with dual gas paths. Through the isolated annular chamber and independent air hole design, signal interference between the two gas paths is avoided; the strength of the gas nozzle is optimized. The gas nozzle and the base are integrally injection molded to disperse mechanical stress and prevent structural deformation or damage caused by high pressure impact; the reverse connection protection design is provided. The directional guide notch corresponds to the SOP16 pin layout, reducing the wiring error rate; the heat dissipation performance is improved. The metal cover plate and the SOP16 pin work together to dissipate heat, quickly dissipating the working heat of the MEMS chip and signal processing components. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model;

[0012] Figure 2 This is a schematic diagram of the present invention from another angle;

[0013] Figure 3 This is an exploded view of the present invention;

[0014] Figure 4 This is a cross-sectional view of the present invention;

[0015] Figure 5 For the present utility model Figure 4 Axonometric drawing;

[0016] Figure 6 This is a perspective view of the present invention.

[0017] Explanation of reference numerals in the attached diagram: 1. Base; 2. Metal cover plate; 3. Mounting slot; 4. Nozzle 1; 5. Nozzle 2; 6. Air pressure chamber; 7. Air hole 1; 8. Air hole 2; 9. MEMS chip; 10. Communication pin; 11. Annular chamber 1; 12. Annular chamber 2; 13. Notch for directional indicator. Detailed Implementation

[0018] The technical solutions of the present utility model will now be described with reference to the accompanying drawings in the embodiments of the present utility model:

[0019] like Figure 1-6The image shows a dual-nozzle gas differential pressure sensor, comprising a base 1 and a metal cover 2. The inner wall of the base 1 has a mounting groove 3, and the metal cover 2 is mounted on the mounting groove 3. Two gas nozzles are located on the base 1, diagonally opposite each other on the top surface. This diagonal design accommodates the thickness of the pipe being measured, ensuring that the pipe can be connected to the gas nozzles. The two gas nozzles are integrally injection molded with the base 1 using reinforcing ribs. The two gas nozzles are designated as Nozzle 1 (4) and Nozzle 2 (5). Both gas nozzles have barbed ends to ensure airtightness and secure installation using flexible hoses. The base 1 contains a built-in pressure chamber 6 and two air vents. The pressure chamber 6 is connected to a corresponding air nozzle via the air vents. The two air vents are designated as vent 1 (7) and vent 2 (8). Vent 1 (7) connects to air nozzle 1 (4), and vent 2 (8) connects to air nozzle 2 (5). A MEMS chip 9 is embedded within the pressure chamber 6. A strain gauge is mounted on the surface of the MEMS chip 9. The MEMS chip 9 is attached to one of the air vents, with one side of the strain gauge connected to the air nozzle and the other side in contact with the pressure chamber 6. Communication pins 10, electrically connected to the MEMS chip 9, are located on both sides of the base 1. The communication pins use a standard SOP16 package for easy mounting on the PCB, ensuring heat dissipation and stability.

[0020] The base 1 is also equipped with two annular chambers, namely annular chamber 11 and annular chamber 2 12. One end of annular chamber 11 is connected to air hole 7 and the other end is connected to air nozzle 4; annular chamber 2 12 is connected to air hole 8 and the other end is connected to air nozzle 5. Through the design of isolated annular chambers and independent air holes, interference between dual air paths is avoided.

[0021] The base 1 has a cuboid structure. One side of the base 1 is provided with a direction guide notch 13. The direction guide notch 13 points to the first pin of the communication pin 10. The direction guide notch 13 can mark the first pin and avoid the problem of reverse connection.

[0022] The working principle of this utility model:

[0023] The dual-nozzle gas differential pressure sensor of this invention achieves accurate measurement and signal output of dual-channel gas differential pressure through the following steps:

[0024] 1. Isolation of air pressure input and air path

[0025] Dual gas path access: The gases from gas path one and gas path two enter the sensor through gas nozzle 4 and gas nozzle 5, respectively.

[0026] Gas path isolation design: After being fixed by the barbed structure at the end of the nozzle, the gas is transmitted to the pressure chamber 6 through two independent annular chambers and air holes. The physical isolation between the annular chambers and the air holes ensures that the pressure signals of the two gas paths do not interfere with each other.

[0027] 2. Pressure difference transmission and membrane deformation

[0028] Air pressure effect: The air pressure from air path one acts on one side of MEMS chip 9, and the air pressure from air path two acts on the other side of MEMS chip 9. When the pressures on both sides are inconsistent, the thin film of the MEMS chip undergoes elastic deformation due to the pressure difference.

[0029] 3. Signal conversion of resistance strain gauge

[0030] Piezoresistive effect: The resistance of a strain gauge integrated on the surface of a thin film changes with the deformation of the film. For example, the resistance decreases on the compression side and increases on the tension side.

[0031] 4. Signal Processing and Output

[0032] Pin transmission: The resistance change of the strain gauge of MEMS chip 9 is converted into an electrical signal by the signal processing chip and output to the external circuit through the SOP16 standard package pins. The pin arrangement corresponds to the direction guide notch 13 to ensure the correct wiring direction.

[0033] 5. Heat dissipation and stability assurance

[0034] Heat conduction: The metal cover plate 2 works in conjunction with the SOP16 standard package pins to dissipate heat, quickly removing the operating heat of the MEMS chip 9 and signal processing components.

[0035] Structural rigidity: The two air nozzles and the base 1 are integrally injection molded to disperse mechanical stress and prevent structural deformation or damage caused by high pressure impact.

[0036] This invention achieves high-precision and high-reliability differential pressure detection through dual-air-path isolation design, MEMS high-precision sensing, reinforced air nozzle structure, reverse connection protection, and optimized heat dissipation. It is particularly suitable for medical equipment and industrial automation.

[0037] The above embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A dual-nozzle gas differential pressure sensor, comprising a base (1) and a metal cover plate (2), characterized in that: The base (1) has a ring of mounting grooves (3) on its inner wall. A metal cover plate (2) is installed on the mounting grooves (3). The base (1) has two air nozzles. The base (1) has a built-in air pressure chamber (6) and two air holes. The air pressure chamber (6) is connected to the corresponding air nozzle through the air holes. The air pressure chamber (6) has a MEMS chip (9) embedded in it. The surface of the MEMS chip (9) is provided with a resistance strain gauge. The MEMS chip (9) is attached to one of the air holes and one side of the resistance strain gauge is connected to the air nozzle. The other side of the resistance strain gauge is in contact with the air pressure chamber (6). The base (1) has communication pins (10) on both sides that are electrically connected to the MEMS chip (9).

2. The dual-nozzle gas differential pressure sensor according to claim 1, characterized in that: The two air nozzles are air nozzle one (4) and air nozzle two (5), and both air nozzles have barbed structures at their ends.

3. The dual-nozzle gas differential pressure sensor according to claim 1, characterized in that: The two vents are vent one (7) and vent two (8), vent one (7) is connected to vent one (4), and vent two (8) is connected to vent two (5).

4. The dual-nozzle gas differential pressure sensor according to claim 1, characterized in that: The base (1) is also provided with two annular chambers, namely annular chamber one (11) and annular chamber two (12). One end of annular chamber one (11) is connected to air hole one (7) and the other end is connected to air nozzle one (4); annular chamber two (12) is connected to air hole two (8) and the other end is connected to air nozzle two (5).

5. The dual-nozzle gas differential pressure sensor according to claim 2, characterized in that: The two air nozzles and the base (1) are integrally injection molded with reinforcing ribs.

6. The dual-nozzle gas differential pressure sensor according to claim 1, characterized in that: The base (1) is a cuboid structure. One side of the base (1) is provided with a direction guide notch (13), which points to the first pin of the communication pin (10).

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