CN216593950U

CN216593950U - Pressure sensor

Info

Publication number: CN216593950U
Application number: CN202122274967.7U
Authority: CN
Inventors: 赵刚; 黄龙圣; 陈文弦
Original assignee: Shanghai Leeg Instruments Co ltd
Current assignee: Shanghai Leeg Instruments Co ltd
Priority date: 2021-09-18
Filing date: 2021-09-18
Publication date: 2022-05-24
Anticipated expiration: 2031-09-18

Abstract

The utility model relates to the technical field of sensors, and discloses a pressure sensor, which comprises: the side wall of the base is provided with a filter sheet groove along the radial direction, one end of the filter sheet groove is communicated with the outside of the sensor, and the other end of the filter sheet groove is communicated with a reference air pressure cavity in the sensor, so that the reference air pressure is ensured to be communicated in the sensor. The porous filter sheet is arranged in the filter sheet groove, so that spark leakage caused by weak current in the pressure sensor can be prevented, and an explosion-proof effect is achieved. So set up, make the reference atmospheric pressure chamber of base from taking explosion-proof function, compressed the product volume. One end of the shell is sleeved outside the base and is configured to prevent the porous filter sheet from falling off from the filter sheet groove along the radial direction, so that the reliability of the pressure sensor is enhanced. The other end of the shell is provided with a through hole, a positive pressure oil cavity is arranged between the through hole and the reference air pressure cavity, and a medium to be detected acts on the positive pressure oil cavity through the through hole to ensure that the sensor detects the external pressure.

Description

Pressure sensor

Technical Field

The utility model relates to the technical field of sensors, in particular to a pressure sensor.

Background

A Pressure Transducer is a device or apparatus that senses a Pressure signal and converts the Pressure signal into a usable output electrical signal according to a certain rule.

The pressure sensor has a limited pressure detection range, so that an explosion-proof device is required to be arranged in the pressure sensor in order to prevent the sensor from exploding due to pressure overtravel or prevent high-pressure gas to be detected from exploding due to sparks generated by weak current in the sensor.

In the prior art, the explosion-proof device needs to be communicated with an atmospheric pressure reference cavity and external atmospheric pressure inside the sensor, and under the condition, if a porous filter sheet in the explosion-proof device falls off due to large internal pressure of the sensor, great potential safety hazards can be caused.

The sensor base integrates the explosion-proof filtering device on the base, the welding sleeve of the outer ring can prevent the porous filtering piece from falling off, so that the atmosphere reference cavity of the base has an explosion-proof function, and the welding sleeve is provided with the waterproof and breathable device to play a role in water resistance and ventilation.

The silicon base integrates the porous filter disc during the core process of the utility model, the anti-drop function is realized by the welding sleeve of the outer ring, and the opening on the sleeve has the function of air, so the utility model is suitable for the structure of directly opening the opening on the sleeve or sticking the breathable film

SUMMERY OF THE UTILITY MODEL

Based on the above, the present invention is directed to provide a pressure sensor, which ensures that a porous filter does not fall off due to a large internal pressure of the sensor, and enhances the explosion-proof reliability of the pressure sensor.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a pressure sensor, comprising:

the side wall of the base is provided with a filter sheet groove along the radial direction, one end of the filter sheet groove is communicated with the outside of the sensor, and the other end of the filter sheet groove is communicated with a reference air pressure cavity in the sensor; a porous filter disc is arranged in the filter disc groove;

the shell is sleeved outside the base, and is configured to prevent the porous filter disc from falling off from the filter disc groove along the radial direction; the other end of the shell is provided with a through hole, a positive pressure oil cavity is arranged between the through hole and the reference air pressure cavity, and the medium to be measured acts on the positive pressure oil cavity through the through hole.

As a preferred scheme of the pressure sensor, the shell is provided with an air hole which is communicated with the filter sheet groove, so that one end of the filter sheet groove is communicated with the outside of the sensor.

As a preferred scheme of the pressure sensor, a waterproof vent plug is arranged in the vent hole.

As a preferable scheme of the pressure sensor, the shell and/or the base are/is provided with an air flow channel, one end of the air flow channel is communicated with the air vent, and the other end of the air flow channel is communicated with the filter sheet groove.

As a preferable scheme of the pressure sensor, the casing comprises a sleeve and a bottom shell, the sleeve is sleeved outside the base and is configured to prevent the porous filter sheet from falling off from the filter sheet groove along the radial direction; one end of the bottom shell is sleeved outside the sleeve, and the other end of the bottom shell is provided with a through hole.

As a preferred scheme of the pressure sensor, a pressure sensing assembly is arranged in the shell and comprises a pressure chip and an isolation diaphragm;

a positive pressure oil cavity is formed between the isolation diaphragm and the base;

silicone oil is filled in the positive pressure oil cavity;

the pressure chip is arranged in the positive pressure oil cavity, and the surface of the pressure chip close to the base is communicated with the filter sheet groove to form a reference air pressure cavity.

As a preferred scheme of the pressure sensor, a diaphragm welding table is arranged between a base and an isolation diaphragm, the diaphragm welding table is connected with the isolation diaphragm, and a first oil cavity is formed between the diaphragm welding table and the isolation diaphragm; a second oil cavity is formed between the membrane welding table and the base; the axial of diaphragm welding bench is equipped with the connecting hole, and the both ends of connecting hole are just to pressure chip and isolation diaphragm respectively.

As a preferable aspect of the pressure sensor, the first oil chamber is a continuous wavy gap.

As a preferred scheme of the pressure sensor, a cock valve grounding needle is further arranged on the base, one end of the cock valve grounding needle is connected with the pressure chip, and the other end of the cock valve grounding needle extends out of the base.

As a preferred scheme of the pressure sensor, the base is provided with an oil filling hole, the oil filling hole is connected with an oil filling pipe, and the oil filling pipe extends out of the base.

The utility model has the beneficial effects that:

the utility model provides a pressure sensor, comprising: the side wall of the base is provided with a filter sheet groove along the radial direction, one end of the filter sheet groove is communicated with the outside of the sensor, and the other end of the filter sheet groove is communicated with a reference air pressure cavity in the sensor, so that the reference air pressure is ensured to be communicated in the sensor. The porous filter sheet is arranged in the filter sheet groove, so that spark leakage caused by weak current in the pressure sensor can be prevented, and an explosion-proof effect is achieved. So set up, make the reference atmospheric pressure chamber of base from taking explosion-proof function, compressed the product volume. One end of the shell is sleeved outside the base and is configured to prevent the porous filter sheet from falling off from the filter sheet groove along the radial direction, so that the reliability of the pressure sensor is enhanced. The other end of the shell is provided with a through hole, a positive pressure oil cavity is arranged between the through hole and the reference air pressure cavity, and a medium to be detected acts on the positive pressure oil cavity through the through hole to ensure that the sensor detects the external pressure.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a cross-sectional view of a pressure sensor provided in accordance with an embodiment of the present invention;

fig. 2 is a partial schematic view of a pressure sensor a provided in accordance with an embodiment of the present invention.

In the figure:

1. a base; 11. a filter sheet groove; 111. a porous filter sheet; 12. a ground pin of the cock valve; 13. an oil charge hole; 14. An oil-filled tube;

2. a housing; 21. a through hole; 22. air holes are formed; 221. a waterproof vent plug; 23. an air flow channel; 24. a pressure chip; 25. an isolation diaphragm; 26. a membrane welding station; 261. connecting holes;

101. a reference air pressure chamber; 102. a positive pressure oil cavity; 1021. a first oil chamber; 1022. a second oil chamber;

201. a sleeve; 202. a bottom shell.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 is a sectional view of a pressure sensor according to an embodiment of the present invention, and referring to fig. 1, the embodiment provides a pressure sensor including: the sensor comprises a base 1 and a shell 2, wherein a filter sheet groove 11 is radially arranged on the side wall of the base 1, one end of the filter sheet groove 11 is communicated with the outside of the sensor, and the other end of the filter sheet groove 11 is communicated with a reference air pressure cavity 101 in the sensor. The filter sheet groove 11 is provided with a porous filter sheet 111. One end of the housing 2 is sleeved outside the base 1 and configured to prevent the porous filter 111 from falling off from the filter groove 11 in the radial direction. The other end of the shell 2 is provided with a through hole 21, a positive pressure oil cavity 102 is arranged between the through hole 21 and the reference air pressure cavity 101, and the medium to be measured acts on the positive pressure oil cavity 102 through the through hole 21.

The base 1 is provided with the filter sheet groove 11, and the porous filter sheet 111 is arranged in the filter sheet groove 11, so that spark leakage caused by weak current in the pressure sensor can be prevented, and an explosion-proof effect is achieved. So set up, make the reference atmospheric pressure chamber 101 of base from taking explosion-proof function, compressed the product volume. Meanwhile, one end of the housing 2 is sleeved outside the base 1 and is configured to prevent the porous filter 111 from falling off from the filter groove 11 along the radial direction, thereby enhancing the reliability of the pressure sensor.

Specifically, referring to fig. 1, the housing 2 is provided with a vent hole 22, and the vent hole 22 is communicated with the filter sheet groove 11, so that one end of the filter sheet groove 11 is communicated with the outside of the sensor, and the reference air pressure is ensured to be communicated in the sensor.

As a preferred technical scheme, a waterproof vent plug 221 is arranged in the vent hole 22, so that the vent hole 22 can play both a ventilating function and a waterproof function. The waterproof vent plug 221 is a mature prior art in the industry and will not be described in detail herein.

More specifically, in the present embodiment, an air flow channel 23 is provided on the inner wall of the housing 2, and one end of the air flow channel 23 is communicated with the air hole 22, and the other end is communicated with the filter sheet groove 11. In other embodiments, the airflow channel 23 may also be disposed on the base 1, or the base 1 and the housing 2 are both provided with ventilation grooves, and the two grooves jointly form the airflow channel 23.

In order to ensure the universality of the pressure sensor and simplify the difficulty of the assembly process, as a preferred technical scheme, the housing 2 comprises a sleeve 201 and a bottom shell 202, the sleeve 201 is sleeved outside the base 1, the sleeve 201 can cover the porous filter 111, and the porous filter 111 is prevented from falling off from the filter groove 11 along the radial direction by a mechanical structure.

The bottom case 202 is in a long tube shape, one end of the bottom case 202 is sleeved outside the sleeve 201, and the other end is provided with a through hole 21. The shell 2 is internally provided with a pressure sensing component for detecting the pressure of the fluid to be detected. The pressure sensing assembly includes a pressure chip 24 and an isolation diaphragm 25. A positive pressure oil cavity 102 is formed between the isolation diaphragm 25 and the base 1, and the positive pressure oil cavity 102 is filled with silicon oil. When the isolation diaphragm 25 bears the external pressure, the isolation diaphragm 25 elastically deforms, and presses the silicone oil in the positive pressure oil chamber 102 inwards, and the pressure is transmitted to the pressure chip 24 through the silicone oil. The pressure chip 24 can convert an external pressure signal into an electric signal, in this embodiment, the pressure chip 24 is disposed in the positive pressure oil chamber 102, and the surface of the pressure chip 24 close to the base 1 is communicated with the filter sheet groove 11 to form a reference pressure chamber 101. The surface of the pressure chip 24 far away from the base 1 is communicated with the positive pressure oil chamber 102 and bears the pressure of the silicone oil in the positive pressure oil chamber 102. By comparing the test pressure with the reference air pressure, the relative pressure of the fluid to be tested in the environment is obtained, and the pressure is converted into an electric signal and then is transmitted to other external equipment through the guide pin.

As a preferable technical scheme, a Korovalve grounding needle 12 is further arranged on the base 1, one end of the Korovalve grounding needle 12 is connected with the pressure chip 24, and the other end of the Korovalve grounding needle 12 extends out of the base 1, so that the grounding problem of the pressure sensor is solved.

Further preferably, the base 1 is provided with an oil filling hole 13, the oil filling hole 13 is connected with an oil filling pipe 14, and the oil filling pipe 14 extends out of the base 1. In the prior art, in order to facilitate the sealing of the sensor after oil filling, the oil filling hole 13 is generally made to be very small, and the steel ball sealing welding is carried out on the port of the oil hole after oil dripping; in the mode, the sealing strength of the sintered base glass insulator can be reduced due to high temperature during sealing and welding, the insulator can be seriously damaged, and oil leakage is directly caused to be scrapped; in addition, when the steel balls are sealed and welded, gas is often mixed, the zero point of the sensor is subjected to uncertain change due to additional pressure, and the overall performance of the sensor is reduced. By integrating the oil fill tube 14 in the base 1, oil filling and sealing by the oil fill tube 14 eliminates the above-mentioned drawbacks caused by oil filling and encapsulation through the oil fill hole 13.

Specifically, fig. 2 is a partial schematic view of a pressure sensor a provided in the embodiment of the present invention, and fig. 2 is referred to. Since the isolation diaphragm 25 is very thin, a diaphragm weld pad 26 needs to be provided between the base 1 and the isolation diaphragm 25 to prevent the isolation diaphragm 25 from being excessively deformed and damaged. After the isolation diaphragm 25 is clamped by the diaphragm pressing ring, the diaphragm pressing ring is welded with the diaphragm welding table 26, so that the isolation diaphragm 25 is connected with the diaphragm welding table 26. After the connection, a first oil chamber 1021 is formed between the diaphragm welding table 26 and the isolation diaphragm 25, and the space of the first oil chamber 1021 is adjustable, but is generally smaller, so that the isolation diaphragm 25 is not damaged due to deformation. A second oil chamber 1022 is formed between the membrane welding table 26 and the base 1; the diaphragm welding table 26 is axially provided with a connecting hole 261, and two ends of the connecting hole 261 are respectively opposite to the pressure chip 24 and the isolation diaphragm 25. When the isolation diaphragm 25 is subjected to pressure, it is elastically deformed to press the silicone oil in the first oil chamber 1021 and transmit the pressure to the pressure chip 24 in the second oil chamber 1022 through the connection hole 261.

As a preferable technical solution, the first oil chamber 1021 is a continuous wavy gap, so that the deformation amount of the isolation diaphragm 25 when the same volume of silicone oil is extruded from the first oil chamber 1021 is smaller, and the resilience and reliability of the isolation diaphragm 25 are enhanced.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the utility model. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Claims

1. A pressure sensor, comprising:

the sensor comprises a base (1), wherein a filter sheet groove (11) is formed in the side wall of the base (1) along the radial direction, one end of the filter sheet groove (11) is communicated with the outside of the sensor, and the other end of the filter sheet groove is communicated with a reference air pressure cavity (101) in the sensor; a porous filter (111) is arranged in the filter sheet groove (11);

the shell (2), one end of the shell (2) is sleeved outside the base (1) and is configured to prevent the porous filter sheet (111) from falling off from the filter sheet groove (11) along the radial direction; the other end of shell (2) is equipped with through-hole (21), through-hole (21) with be equipped with malleation oil pocket (102) between reference atmospheric pressure chamber (101), the medium that awaits measuring passes through-hole (21) will be pressed on malleation oil pocket (102).

2. A pressure sensor according to claim 1, wherein the housing (2) is provided with a vent (22), and the vent (22) is communicated with the filter sheet groove (11), so that one end of the filter sheet groove (11) is communicated with the outside of the sensor.

3. A pressure sensor according to claim 2, characterized in that a waterproof venting plug (221) is provided in the venting hole (22).

4. A pressure sensor according to claim 2, characterized in that the housing (2) and/or the base (1) is provided with an air flow channel (23), one end of the air flow channel (23) being in communication with the air vent (22) and the other end being in communication with the filter plate slot (11).

5. The pressure sensor according to claim 1, wherein the housing (2) comprises a sleeve (201) and a bottom shell (202), the sleeve (201) is sleeved outside the base (1) and is configured to prevent the porous filter sheet (111) from falling off from the filter sheet groove (11) along a radial direction; one end of the bottom shell (202) is sleeved outside the sleeve (201), and the other end of the bottom shell is provided with a through hole (21).

6. A pressure sensor according to claim 1, wherein a pressure sensing assembly is provided within the housing (2), the pressure sensing assembly comprising a pressure chip (24) and an isolation diaphragm (25);

the positive pressure oil chamber (102) is formed between the isolation diaphragm (25) and the base (1);

the positive pressure oil cavity (102) is filled with silicon oil;

the pressure chip (24) is arranged in the positive pressure oil cavity (102), the surface of the pressure chip (24) close to the base (1) is communicated with the filter sheet groove (11), and the reference air pressure cavity (101) is formed.

7. The pressure sensor according to claim 6, wherein a diaphragm welding station (26) is arranged between the base (1) and the isolation diaphragm (25), the diaphragm welding station (26) is connected with the isolation diaphragm (25) and forms a first oil chamber (1021) with the isolation diaphragm (25); a second oil chamber (1022) is formed between the membrane welding table (26) and the base (1); the axial of diaphragm welding platform (26) is equipped with connecting hole (261), the both ends of connecting hole (261) are just right respectively pressure chip (24) with isolation diaphragm (25).

8. The pressure sensor of claim 7, wherein the first oil chamber (1021) is a continuous wave-like gap.

9. A pressure sensor as claimed in claim 6, wherein the base (1) is further provided with a Korovalve grounding pin (12), one end of the Korovalve grounding pin (12) is connected with the pressure chip (24), and the other end of the Korovalve grounding pin (12) extends out of the base (1).

10. The pressure sensor according to claim 1, wherein the base (1) is provided with an oil filling hole (13), the oil filling hole (13) is connected with an oil filling pipe (14), and the oil filling pipe (14) extends out of the base (1).