A pressure sensor for measuring a dielectric medium

Abstract

The utility model discloses a kind of pressure sensors for measuring conducting medium, it is related to pressure sensor technical field, including shell assembly and sensing component, shell assembly includes shell, shield and insulating cylinder, shell has the medium inlet and inner chamber of intercommunication, shell has output interface on the side away from medium inlet;Shield is located inner chamber and its bottom and the side wall of medium inlet are coated with insulating coating, the bottom of shield is communicated with medium inlet, and insulating cylinder is located between shield and inner chamber cavity wall.Sensing component includes the pressure sensing element and signal output piece of interconnection, pressure sensing element is located in the inside of shield and is connected to the inner wall of shield, and signal output piece is located in output interface.The application is coated with insulating coating on the bottom of shield and the side wall of medium inlet, and insulating cylinder is arranged between shield and inner chamber cavity wall, effectively isolates conducting medium and internal circuit, avoids internal circuit breakdown damage under high voltage effect.

Description

Technical Field

[0001] This utility model relates to the field of pressure sensor technology, and specifically to a pressure sensor for measuring conductive media. Background Technology

[0002] Pressure sensors are widely used in ventilation systems, air conditioning, industrial energy storage, and other fields to measure the pressure of various media. Traditional pressure sensors mainly use a shield made of metal to terminate the interference sources they generate inside the cylindrical shield through grounding. Due to the conductivity of the inner shield, existing pressure sensors can only measure non-conductive media.

[0003] Because there is no insulating layer between the pressure sensor's interior and the shielding cover, when a conductive medium enters the sensor and comes into contact with the conductive inner shielding cover, a conductive channel is formed, connecting the internal circuitry to the external conductive medium. If a high voltage is applied to the outer casing, it can be transmitted to the internal circuitry through the conductive medium, easily causing the internal circuitry to break down and be damaged. Utility Model Content

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a pressure sensor for measuring conductive media. This solves the technical problem in the prior art where no insulating layer is provided between the inside of the pressure sensor and the shielding cover, and high voltage is applied to the outer shell and transmitted to the internal circuit through the conductive medium, which can easily lead to the breakdown and damage of the internal circuit.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: This utility model provides a pressure sensor for measuring conductive media, comprising: A housing assembly includes a housing, a shield, and an insulating cylinder. The housing has a communicating medium inlet and an inner cavity, and an output interface is located on the side of the housing away from the medium inlet. The shield is located within the inner cavity, and its bottom and the sidewall of the medium inlet are coated with an insulating coating. The bottom of the shield communicates with the medium inlet. The insulating cylinder is located between the shield and the inner cavity wall. The sensing component includes a pressure sensing element and a signal output element. The pressure sensing element is located inside the shield and connected to the inner wall of the shield. The signal output element is located at the output interface and connected to the pressure sensing element.

[0006] In some embodiments, the housing assembly further includes a first insulating pad located at the bottom of the inner cavity, the shield being placed on the first insulating pad and spaced apart from the bottom of the inner cavity to form a first isolation cavity, the first isolation cavity communicating with the medium inlet and the interior of the shield.

[0007] In some embodiments, the housing assembly further includes a first insulating sealing ring located in the first isolation cavity, the outer wall of the first insulating sealing ring abutting against the first insulating pad.

[0008] In some embodiments, the shielding cover has a receiving cavity, and the housing assembly further includes a second insulating pad, the second insulating pad being located at the bottom of the receiving cavity and attached to the cavity wall of the receiving cavity, and the sensing component being located in the receiving cavity and placed on the second insulating pad.

[0009] In some embodiments, the housing assembly further includes a second insulating sealing ring located in the receiving cavity, the outer wall of the second insulating sealing ring abutting against the second insulating pad.

[0010] In some embodiments, the pressure sensing element includes a sensor and a conditioning circuit board connected together, the sensor being connected to the medium inlet, and the grounding wire of the conditioning circuit board being connected to the signal output element and the inner wall of the shield.

[0011] In some embodiments, the signal output device includes an output connector, a positive electrode needle, a negative electrode needle, and a ground electrode needle. The output connector is snapped into the shield and has the output interface. The input ends of the positive electrode needle, the negative electrode needle, and the ground electrode needle are all connected to the conditioning circuit board, and the output ends are located at the output interface.

[0012] In some embodiments, the output interface includes a socket and a countersunk hole, the countersunk hole being formed at the bottom of the socket, and the positive electrode pin, negative electrode pin, and ground electrode pin passing through the countersunk hole and extending into the socket.

[0013] In some embodiments, the gap between the output connector and the housing is filled with sealant.

[0014] In some embodiments, the outer casing has a plug-in slot, the medium inlet connects the plug-in slot to the inner cavity, and the plug-in slot has a positioning post.

[0015] Compared with existing technologies, the pressure sensor for measuring conductive media provided by this utility model allows the conductive medium to enter the inner cavity through the medium inlet of the outer shell. The conductive medium acts on the sensing diaphragm of the pressure sensing element, causing the diaphragm to deform and thus changing the value of the variable capacitance. The pressure sensing element amplifies and conditions the capacitance change signal, converting it into a voltage signal of a corresponding proportion. The conditioned voltage signal is output through a signal output device for subsequent equipment to measure and process. This application effectively isolates the conductive medium from the internal circuit by coating the bottom of the shield and the side wall of the medium inlet with an insulating coating, and by setting an insulating cylinder between the shield and the inner cavity wall, preventing the conductive medium from forming a conductive path with the shield, thereby avoiding the problem of internal circuit breakdown and damage under high voltage. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of the pressure sensor provided in an embodiment of the present invention from one perspective; Figure 2 This is a structural schematic diagram of the pressure sensor provided in another embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of the pressure sensor provided in an embodiment of this utility model. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0018] To address the technical problem in existing pressure sensors where no insulating layer is provided between the sensor's interior and the shield, high voltage applied to the outer shell can be transmitted to the internal circuitry via the conductive medium, easily leading to circuit breakdown and damage. This invention provides a pressure sensor for measuring conductive media. By coating the bottom of the shielding cover and the sidewall of the medium inlet with an insulating layer, and by placing an insulating cylinder between the shielding cover and the inner cavity wall, the conductive medium and the internal circuitry are effectively isolated, preventing the conductive medium from forming a conductive path with the shielding cover and avoiding damage to the internal circuitry under high voltage.

[0019] It should be noted that the pressure sensor for measuring conductive media described in this utility model is used for, but not limited to, pressure detection of conductive media. For ease of explanation, this utility model only uses the application of the pressure sensor for measuring conductive media to conductive media as an example. The principle of the pressure sensor for measuring conductive media applied to other types of equipment is essentially the same as that applied to conductive media, and will not be described in detail here.

[0020] Please see Figures 1 to 3, Figure 1 This is a schematic diagram of the structure of a pressure sensor for measuring conductive media in one embodiment of the present invention. The pressure sensor 100 for measuring conductive media includes a housing assembly 1 and a sensing assembly 2. The housing assembly 1 includes a housing 11, a shield 12 and an insulating cylinder 13. The housing 11 has a medium inlet 111 and an inner cavity 112 that are connected. The side of the housing 11 away from the medium inlet 111 has an output interface 113. The shield 12 is located in the inner cavity 112 and its bottom and the side wall of the medium inlet 111 are coated with an insulating coating. The bottom of the shield 12 is connected to the medium inlet 111. The insulating cylinder 13 is located between the shield 12 and the cavity wall of the inner cavity 112.

[0021] The sensing component 2 includes a pressure sensing element 21 and a signal output element 22. The pressure sensing element 21 is located inside the shield 12 and connected to the inner wall of the shield 12. The signal output element 22 is located at the output interface 113 and connected to the pressure sensing element 21.

[0022] In this embodiment, the housing 11 can be made of high-strength, corrosion-resistant materials such as brass, aluminum alloy, or stainless steel, possessing excellent mechanical and protective properties. The medium inlet 111 of the housing 11 can be configured as a threaded interface for easy connection to an external pipeline, which stably supplies conductive medium into the inner cavity 112. The output interface 113 of the housing 11 is located on the side of the housing 11 away from the medium inlet 111, employing a standard electrical interface design for easy connection to external devices.

[0023] The shielding cover 12 can be made of aluminum alloy A6061 or stainless steel, which has excellent corrosion resistance and mechanical strength. The bottom of the shielding cover 12 and the sidewalls of the medium inlet 111 are coated with an insulating coating, which can be made of parylene and formed into a dense, pinhole-free nanofilm layer through chemical vapor deposition (CVD). The bottom of the shielding cover 12 is connected to the medium inlet 111, allowing the conductive medium to enter the interior of the shielding cover 12 through the medium inlet 111 to contact the pressure sensing element 21 inside the shielding cover 12.

[0024] The insulating cylinder 13 is made of flexible cylindrical insulating paper material. The insulating paper is flexible and has extremely strong flexibility and mechanical strength. When the upper part of the outer shell 11 is bent, the cylindrical insulating paper bends accordingly, and it can ensure that the insulating paper is not damaged after bending. It isolates the shielding cover 12 and the outer shell 11, ensuring that the two conductors cannot be connected.

[0025] The pressure sensing element 21 includes a sensing element 211 and a conditioning circuit board 212. The sensing element 211 may be made of ceramic, possessing good corrosion resistance and mechanical properties, and can maintain stable performance under the influence of high-pressure conductive media. The sensing diaphragm of the sensing element 211 can sense pressure changes in the conductive media, causing the diaphragm to deform, thereby changing the value of the variable capacitance. The conditioning circuit board 212 may be made of polyimide (PI) as the substrate, possessing good high-temperature resistance and insulation properties. One end of the conditioning circuit board 212 is connected to three pins of the sensing element 211, and the other end is connected to three pins of the signal output element 22 via soldering. The conditioning circuit board 212 can amplify and condition the capacitance change signal generated by the sensing element 211, converting it into a proportional voltage signal output. Furthermore, the pressure sensing element 21 is located inside the shielding cover 12 and connected to the inner wall of the shielding cover 12; specifically, the conditioning circuit board 212 is connected to the inner wall of the shielding cover 12. The conditioning circuit board 212 is connected to three pins of the signal output component 22. These three pins are the power supply voltage input line, the signal output line, and the ground line, respectively. The ground line, the two flexible thin plate-shaped pins in the conditioning circuit board 212, and the inner wall of the shield 12 form a conductive loop, thereby terminating the electromagnetic field generated by the capacitors, resistors, chips, and other components in the conditioning circuit board 212 at the inner wall of the shield 12. Then, the ground line introduces the charge generated by the internal electric or magnetic field into the ground, thus preventing electromagnetic interference.

[0026] The signal output component 22 includes an output connector 221 and positive electrode pins 222, negative electrode pins 223, and ground electrode pins 224 disposed on the output connector 221. The output connector 221 is made of metal, possessing good conductivity and mechanical strength, ensuring stable signal output. The positive electrode pins 222, negative electrode pins 223, and ground electrode pins 224 are used to transmit power supply voltage signals and ground signals, respectively, ensuring the normal operation of the conditioning circuit board 212. The output connector 221 snaps into the output interface 113 of the shielding cover 12, ensuring reliable connection. At the end of the output connector 221 away from the shielding cover 12, there is a socket 225 and a countersunk hole 226. The countersunk hole 226 is formed at the bottom of the socket 225. The positive electrode pins 222, negative electrode pins 223, and ground electrode pins 224 pass through the countersunk hole 226 and extend into the socket 225, enabling the signal output component 22 to reliably connect to external devices and ensuring accurate transmission of measurement signals.

[0027] The conductive medium enters the inner cavity 112 through the medium inlet 111 of the outer shell 11, and then enters the interior of the shield 12 through the bottom of the shield 12. The threaded interface of the medium inlet 111 ensures a reliable connection with the external pipeline to prevent leakage of the conductive medium.

[0028] A conductive medium acts on the sensing element 211 of the pressure sensing element 21, causing deformation of the sensing diaphragm of the sensing element 211, thereby changing the value of the variable capacitance. The sensing element 211 is made of ceramic material, which has good corrosion resistance and mechanical properties, and can maintain stable performance under the action of high-pressure conductive medium. The conditioning circuit board 212 amplifies and conditions the capacitance change signal generated by the sensing element 211, converting it into a proportional voltage signal. The conditioning circuit board 212 uses polyimide (PI) as the substrate, which has good high-temperature resistance and insulation properties, and can ensure stable signal transmission.

[0029] The conditioned voltage signal is output through signal output component 22 for subsequent equipment to measure and process. The output connector 221 of signal output component 22 is made of metal, which has good conductivity and mechanical strength to ensure stable signal output.

[0030] Through the above design, the pressure sensor for measuring conductive media of this utility model can maintain high insulation performance when measuring conductive media, effectively preventing the internal circuit from being damaged by breakdown, while improving the sensor's anti-electromagnetic interference ability and corrosion resistance, making it suitable for various complex working environments.

[0031] In one embodiment, please refer to Figure 3 The outer casing assembly 1 also includes a first insulating pad 14, which is located at the bottom of the inner cavity 112. The shielding cover 12 is placed on the first insulating pad 14 and forms a first isolation cavity 114 with the bottom of the inner cavity 112 as a gap. The first isolation cavity 114 connects the medium inlet 111 and the interior of the shielding cover 12. In this embodiment, the first insulating pad 14 can be made of polytetrafluoroethylene (PTFE), which has good insulation and corrosion resistance, and can effectively isolate the conductive path between the shielding cover 12 and the bottom of the inner cavity 112.

[0032] Further, please refer to Figure 3 The housing assembly 1 also includes a first insulating sealing ring 15, which is located in the first isolation cavity 114, and the outer wall of the first insulating sealing ring 15 abuts against the first insulating pad 14. In this embodiment, the first insulating sealing ring 15 can be made of hydrogenated nitrile butadiene rubber (HNBR) or ethylene propylene diene monomer rubber (EPDM) with excellent corrosion resistance, which can effectively prevent conductive medium from leaking through the first isolation cavity 114, further enhancing the sealing performance of the sensor.

[0033] In one embodiment, please refer to Figure 3The shielding cover 12 has a receiving cavity 121 inside. The outer shell assembly 1 also includes a second insulating pad 16. The second insulating pad 16 is located at the bottom of the receiving cavity 121 and is attached to the cavity wall of the receiving cavity 121. The sensing component 2 is located in the receiving cavity 121 and is placed on the second insulating pad 16. In this embodiment, the second insulating pad 16 can also be made of PPS (polyphenylene sulfide) + 40%GF (glass fiber) material with excellent corrosion resistance and good insulation performance, which can effectively isolate the conductive path between the sensing component 2 and the shielding cover 12 and protect the sensing component 2 from the influence of conductive media.

[0034] Further, please refer to Figure 3 The housing assembly 1 also includes a second insulating sealing ring 17, which is located in the accommodating cavity 121, and the outer wall of the second insulating sealing ring 17 abuts against the second insulating pad 16. In this embodiment, the second insulating sealing ring 17 is made of the same hydrogenated nitrile butadiene rubber (HNBR) or ethylene propylene diene monomer (EPDM) as the first insulating sealing ring 15, which further enhances the sealing performance of the accommodating cavity 121 and ensures that conductive media will not enter the area where the sensing assembly 2 is located.

[0035] In one embodiment, please refer to Figure 3 The pressure sensing element 21 includes a sensing element 211 and a conditioning circuit board 212 connected together. The sensing element 211 is connected to the medium inlet 111, and the ground wire of the conditioning circuit board 212 is connected to the signal output element 22 and the inner wall of the shield 12. The sensing element 211 is made of ceramic material, which has good corrosion resistance and mechanical properties, and can maintain stable performance under the action of high-pressure conductive medium. The conditioning circuit board 212 uses polyimide (PI) as the substrate, which has good high temperature resistance and insulation properties, and can amplify and condition the capacitance change signal generated by the sensing element 211, converting it into a proportional voltage signal output.

[0036] In one embodiment, please refer to Figure 3The signal output component 22 includes an output connector 221, a positive electrode needle 222, a negative electrode needle 223, and a ground electrode needle 224. The output connector 221 has the aforementioned output interface 113. The input ends of the positive electrode needle 222, negative electrode needle 223, and ground electrode needle 224 are all connected to the conditioning circuit board 212, and their output ends are all located in the output interface 113. The output connector 221 is snapped into the shielding cover 12. In this embodiment, the positive electrode needle 222, negative electrode needle 223, and ground electrode needle 224 are all made of highly conductive copper alloy material, which has good conductivity and corrosion resistance. The input ends of these electrode needles are connected to the corresponding solder points of the conditioning circuit board 212 by welding or crimping to ensure stable signal transmission. The output ends are located inside the output interface 113, allowing external devices to make electrical connections with these electrode needles when connecting the output connector 221. Positive electrode pin 222 is used to transmit power supply voltage, negative electrode pin 223 is used to transmit signals, and ground electrode pin 224 is used to ground, ensuring the normal operation of conditioning circuit board 212 and stable signal output.

[0037] The conditioning circuit board 212 amplifies and conditions the capacitance change signal generated by the pressure sensing element 21, converting it into a proportional voltage signal. These signals are transmitted through the output terminal of the conditioning circuit board 212 to the input terminals of the positive electrode needle 222, the negative electrode needle 223, and the ground electrode needle 224.

[0038] In one embodiment, please refer to Figure 2 The output interface 113 includes a socket 225 and a countersunk hole 226. The countersunk hole 226 is formed at the bottom of the socket 225. The positive electrode needle 222, the negative electrode needle 223, and the ground electrode needle 224 all pass through the countersunk hole 226 and extend into the socket 225. In this embodiment, by providing the socket 225 and the countersunk hole 226, the signal output component 22 can reliably connect to external devices, ensuring accurate transmission of measurement signals. The output ends of the positive electrode needle 222, the negative electrode needle 223, and the ground electrode needle 224 are electrically connected to external devices through the socket 225 and the countersunk hole 226, allowing the external devices to stably connect to the output connector 221 and preventing loosening or poor contact.

[0039] In one embodiment, please refer to Figure 3 The gap between the output connector 221 and the housing 11 is filled with sealant 227. In this embodiment, the sealant 227 can be made of RTV silicone rubber, which has good waterproof performance, does not crack at high and low temperatures, and can effectively prevent external moisture and dust from entering the sensor, further enhancing the sensor's protective performance.

[0040] In one embodiment, please refer to Figure 3The outer casing 11 has a plug-in slot 115, and the medium inlet 111 connects the plug-in slot 115 to the inner cavity 112. The plug-in slot 115 has a positioning post 116. In this embodiment, by setting the plug-in slot 115 and the positioning post 116, the sensor can be quickly positioned during installation, ensuring the accurate connection between the medium inlet 111 and the external pipeline, thereby improving the installation efficiency and reliability of the sensor.

[0041] To better understand this utility model, the following is combined with... Figures 1 to 3 The technical solution of this utility model is described in detail below: The conductive medium of the pressure sensor 100 provided by this utility model enters the inner cavity 112 through the medium inlet 111 of the outer shell 11. The conductive medium acts on the sensing diaphragm of the pressure sensing element 21, causing the sensing diaphragm to deform, thereby changing the value of the variable capacitance. The pressure sensing element 21 amplifies and conditions the capacitance change signal, converting it into a voltage signal of corresponding proportion. The conditioned voltage signal is output through a signal output device for subsequent equipment to measure and process. This application effectively isolates the conductive medium from the internal circuit by coating the bottom of the shielding cover 12 and the side wall of the medium inlet 111 with an insulating coating, and by setting an insulating cylinder 13 between the shielding cover 12 and the cavity wall of the inner cavity 112, preventing the conductive medium from forming a conductive path with the shielding cover 12, thereby avoiding the problem of internal circuit breakdown and damage under high voltage.

[0042] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A pressure sensor for measuring conductive media, characterized in that, include: A housing assembly includes a housing, a shield, and an insulating cylinder. The housing has a communicating medium inlet and an inner cavity, and an output interface is located on the side of the housing away from the medium inlet. The shield is located in the inner cavity and its bottom and the sidewall of the medium inlet are coated with an insulating coating. The bottom of the shield communicates with the medium inlet. The insulating cylinder is located between the shield and the inner cavity wall. and The sensing component includes a pressure sensing element and a signal output element. The pressure sensing element is located inside the shield and connected to the inner wall of the shield. The signal output element is located at the output interface and connected to the pressure sensing element.

2. The pressure sensor for measuring conductive media according to claim 1, characterized in that, The housing assembly further includes a first insulating pad located at the bottom of the inner cavity. The shield is placed on the first insulating pad and spaced apart from the bottom of the inner cavity to form a first isolation cavity. The first isolation cavity communicates with the medium inlet and the interior of the shield.

3. The pressure sensor for measuring conductive media according to claim 2, characterized in that, The housing assembly further includes a first insulating sealing ring located in the first isolation cavity, with the outer wall of the first insulating sealing ring abutting against the first insulating pad.

4. The pressure sensor for measuring conductive media according to claim 1, characterized in that, The shielding cover has a receiving cavity, and the outer shell assembly also includes a second insulating pad. The second insulating pad is located at the bottom of the receiving cavity and is attached to the cavity wall of the receiving cavity. The sensing component is located in the receiving cavity and is placed on the second insulating pad.

5. The pressure sensor for measuring conductive media according to claim 4, characterized in that, The housing assembly further includes a second insulating sealing ring located in the receiving cavity, with the outer wall of the second insulating sealing ring abutting against the second insulating pad.

6. The pressure sensor for measuring conductive media according to claim 1, characterized in that, The pressure sensing element includes a sensor and a conditioning circuit board connected together. The sensor is connected to the medium inlet, and the ground wire of the conditioning circuit board is connected to the signal output element and the inner wall of the shield.

7. The pressure sensor for measuring conductive media according to claim 6, characterized in that, The signal output device includes an output connector, a positive electrode needle, a negative electrode needle, and a ground electrode needle. The output connector is snapped into the shield and has the output interface. The input ends of the positive electrode needle, the negative electrode needle, and the ground electrode needle are all connected to the conditioning circuit board, and the output ends are located at the output interface.

8. The pressure sensor for measuring conductive media according to claim 7, characterized in that, The output interface includes a socket and a countersunk hole. The countersunk hole is formed at the bottom of the socket. The positive electrode needle, negative electrode needle, and ground electrode needle pass through the countersunk hole and extend into the socket.

9. The pressure sensor for measuring conductive media according to claim 7, characterized in that, The gap between the output connector and the housing is filled with sealant.

10. The pressure sensor for measuring conductive media according to claim 1, characterized in that, The outer shell has a plug-in slot, the medium inlet connects the plug-in slot to the inner cavity, and the plug-in slot has a positioning post.

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