CN115507994A

CN115507994A - Gauge pressure sensor

Info

Publication number: CN115507994A
Application number: CN202211226939.0A
Authority: CN
Inventors: 王小平; 曹万; 张超军; 梁世豪; 洪鹏
Original assignee: Wuhan Finemems Inc
Current assignee: Wuhan Finemems Inc
Priority date: 2022-10-09
Filing date: 2022-10-09
Publication date: 2022-12-23

Abstract

A gauge pressure sensor, comprising: a housing; the separation assembly is used for separating the inner cavity of the shell into a first cavity and a second cavity, the separation assembly is provided with a through hole for communicating the first cavity with the second cavity, and the second cavity is communicated to the outside of the shell through a gauge pressure hole formed in one longitudinal side of the shell; the pressure sensing surface of the pressure chip plugs the through hole from the opposite side of the longitudinal side of the second cavity; the circuit board is arranged in the second cavity and connected with the pressure chip; and a pressure joint pipe connected to one longitudinal side of the casing and communicated to the second cavity. The gauge pressure sensor can effectively reduce the invasion of water and dust.

Description

Gauge pressure sensor

Technical Field

The application relates to the technical field of pressure sensors, in particular to a gauge pressure sensor.

Background

The MEMS pressure sensor measures pressure by using piezoresistive effect of a micromachined semiconductor material, and senses pressure of an external medium by means of a pressure membrane, and a resistance value of a piezoresistive element on the pressure membrane is changed when the piezoresistive element receives pressure transmitted from the pressure membrane. The pressure can be judged by monitoring the change of the resistance value, and the pressure is converted into an electric signal through a circuit and then is output to a peripheral circuit control system. The pressure sensor comprises an absolute pressure sensor, a gauge pressure sensor and a differential pressure sensor, wherein the gauge pressure sensor introduces the pressure to be measured at one side of the pressure membrane, and introduces the atmospheric pressure at the other side of the pressure membrane.

The conventional gauge pressure sensor generally includes a housing and an upper cover, a pressure port for introducing a pressure to be measured is disposed at a bottom, and a gauge pressure hole for introducing atmospheric pressure is disposed at a top or a side. In order to isolate rain from the working environment, a waterproof breathable film is generally required to be arranged at the gage pressure hole.

However, the present application has found that the above-mentioned techniques still have at least some technical problems, for example, when the amount of rain water is large and drainage is not smooth, rain water is likely to completely cover the waterproof breathable film, and the ventilation effect is not achieved.

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Disclosure of Invention

In view of the deficiencies of the prior art, the present application provides a gauge pressure sensor to avoid the blockage of a waterproof breathable membrane covered by water.

In order to achieve the above purpose, the present application provides the following technical solutions: a gauge pressure sensor, comprising:

a housing;

the separation assembly is used for separating the inner cavity of the shell into a first cavity and a second cavity, the separation assembly is provided with a through hole for communicating the first cavity with the second cavity, and the second cavity is communicated to the outside of the shell through a gauge pressure hole formed in one longitudinal side of the shell;

the pressure sensing surface of the pressure chip seals the through hole from the opposite side of the longitudinal side of the second cavity;

the circuit board is arranged in the second cavity and connected with the pressure chip;

and a pressure joint pipe connected to the longitudinal side of the housing and communicated to the second chamber.

Preferably, a waterproof breathable film is arranged at the gage pressure hole.

Preferably, the waterproof breathable film is arranged at one end of the inner side of the gauge pressure hole, a heightening frame is arranged between the waterproof breathable film and the inner wall of the shell, and/or a circle of enclosure and/or glue separation groove positioned around the waterproof breathable film is arranged on the shell.

Preferably, the gauge pressure ports are two, and the two gauge pressure ports are aligned with each other in a first direction perpendicular to the longitudinal direction.

Preferably, a plurality of fisheye contact pins are fixed in the shell, a plurality of contact pin holes are correspondingly formed in the circuit board, and one ends of the fisheye contact pins are correspondingly clamped in the contact pin holes.

Preferably, the gauge pressure holes are two, and the gauge pressure holes are arranged along a first direction perpendicular to the longitudinal direction; the three fisheye pins are arranged in a first direction perpendicular to the longitudinal direction, one fisheye pin penetrates through a portion, located between the two gauge pressure holes, of the shell, and the other two fisheye pins penetrate through portions, located on the opposite sides of the two gauge pressure holes, of the shell respectively.

Preferably, a ring of drainage grooves are formed by inward depression of the edge of one longitudinal side surface of the shell, a ring of flanges are formed by opposite outward protrusion of the edge of one longitudinal side surface of the shell, and drainage ports communicated with the drainage grooves are formed at corners of the flanges.

Preferably, the longitudinal side surface of the casing is formed with two convex portions protruding outward relative to the drain groove, and the two convex portions are respectively located on opposite sides of the gauge pressure holes.

Preferably, the boss is flush with the longitudinal side of the flange in a transverse plane.

Preferably, the pressure connector tube extends longitudinally.

The application has the following effects: the gauge pressure hole is arranged at one side of the pressure joint pipe, the waterproof breathable film is arranged, and the drainage channel is arranged, so that the invasion of water and dust can be reduced to the greatest extent; in addition, the surrounding of the waterproof breathable film is provided with a surrounding baffle and/or a glue separating groove and/or a heightening frame, so that the waterproof breathable film can be further prevented from being blocked by glue used in the assembly of the shell; the waterproof breathable film can be further clamped in the pin hole in the circuit board through the fisheye pin, can be riveted after being positioned through the positioning riveting column, and is sealed through the compressed sealing gasket, so that glue-free connection is achieved, the risk that the waterproof breathable film is blocked by glue in the assembling process is reduced as much as possible, and the assembling is convenient.

Drawings

FIG. 1 is a top view of a gauge pressure sensor in accordance with a preferred embodiment;

FIG. 2 is a bottom view of a preferred embodiment gauge pressure sensor;

FIG. 3 isbase:Sub>A cross-sectional view ofbase:Sub>A preferred embodiment gauge pressure sensor taken along A-A shown in FIG. 1;

FIG. 4 is a front view of a preferred embodiment gauge pressure sensor;

FIG. 5 is an enlarged schematic view of detail B shown in FIG. 3;

FIG. 6 is an enlarged schematic view corresponding to detail B shown in FIG. 3 in another embodiment;

FIG. 7 is a cross-sectional view of a preferred embodiment gauge pressure sensor taken along C-C shown in FIG. 4;

in the figure: 1. a main housing; 2. a push button; 3. a pressure connector tube; 4. a media channel; 5. a seal ring; 6. a support surface; 7. a rib is protruded; 8. a sealing gasket; 9. a second through hole; 10. a substrate; 11. a first through hole; 12. a pressure chip; 13. a circuit board; 14. a pin inserting hole; 16. positioning the riveting column; 17. a cover body; 18. a yielding concave part; 19. gage pressure vent; 20. a waterproof breathable film; 21. a heightening frame; 22. a wire; 23. a water outlet; 24. a bottom surface; 25. a boss portion; 26. a flange; 27. a water discharge tank; 28. covering the gel; 29. a guide portion; 30. a joint pipe mounting portion; 151. a first fisheye pin; 152. a second fisheye pin; 171. a glue tank.

Detailed Description

The technical solution of the present application will be clearly and completely described below with reference to the accompanying drawings. The following examples are illustrative only and are not to be construed as limiting the present application. In the following description, the same reference numerals are used to designate the same or equivalent elements, and the repetitive description is omitted.

In the description of the present application, it is to be understood that the terms "upper", "lower", "inner", "outer", "left", "right", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships that the products of the present invention are conventionally placed in use, or the orientations or positional relationships that are conventionally understood by those skilled in the art, and are used for convenience of describing the present application and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

In addition, the terms "mounted," "connected," and "coupled" are to be construed broadly and may include, for example, fixed connections, removable connections, or integral connections; 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 meaning of the above terms in the present application can be understood as appropriate by those of ordinary skill in the art.

It should be further understood that the term "and/or" as used in this specification and the corresponding claims refers to any and all possible combinations of one or more of the listed items.

Please refer to fig. 1 to 4. In a preferred embodiment of the present application, the gauge pressure sensor includes a housing, a divider assembly, a pressure chip 12, a circuit board 13, and a pressure connector 3. The separating assembly separates the inner cavity of the shell into a first cavity and a second cavity. The pressure sensing face of the pressure chip 12 blocks the through hole from the opposite side of the longitudinal side of the second cavity.

The first chamber is mainly used for introducing a medium to be measured in pressure to the pressure sensing surface of the pressure chip 12, and the second chamber is communicated to the outside (such as the atmosphere) of the shell through a gauge pressure hole 19 to introduce a reference pressure to the pressure reference surface of the pressure chip 12. The separating component is provided with a through hole for communicating the first cavity with the second cavity. The pressure reference surface and the pressure sensing surface are two opposite surfaces of the pressure chip 12, respectively, and the pressure chip 12 generates resistance value change under the action of pressure difference (gauge pressure) on two sides, so that the pressure difference on two sides can be represented by measuring the resistance value change. Wherein, the circuit board 13 is disposed in the second cavity and connected to the pressure chip 12 through a wire 22. The pressure joint pipe 3 is connected to one longitudinal side of the shell and communicated to the second cavity so as to introduce a medium to be measured in pressure into the first cavity.

The housing may be formed by combining the main housing 1 and the cover 17, for example, the cover 17 is fastened on an opening at the upper end of the main housing 1 and may be adhered by glue. Preferably, the pressure joint pipe 3 extends in the longitudinal direction, but in other embodiments, the pressure joint pipe 3 may be arranged obliquely to the longitudinal direction. In other embodiments, the gage pressure port 19 may be opened at one longitudinal side (lower side in fig. 3, 4) of the housing to communicate with one lateral end (left end in fig. 3, 4) of the second chamber toward the opposite longitudinal side (upper side in fig. 3, 4).

Therefore, when the pressure joint pipe 3 is inserted into the working equipment, the lower side surface of the pressure joint pipe can be close to the working equipment, and compared with the situation that the gauge pressure hole is arranged at the top or the side part, the risk that water vapor and dust enter from the gauge pressure hole 19 is reduced.

In other embodiments, a waterproof and breathable membrane 20 is installed at the gauge pressure hole 19 to isolate moisture and dust from the second cavity, so as to protect the circuit board 13 and the pressure chip 12.

Referring to fig. 5, in other embodiments, a waterproof breathable membrane 20 is preferably installed at one end of the inner side of the gauge pressure hole 19. A heightening frame 21 (shown in fig. 6) can be arranged between the waterproof breathable film 20 and the inner wall of the shell, and/or a circle of enclosing barrier and/or glue separating groove is arranged around the waterproof breathable film 20, and the enclosing barrier and the glue separating groove are both arranged on the shell. This prevents the water-proof air-permeable membrane 20 from being clogged after the glue flows to the bottom when the upper cover 12 is adhered to the main casing 1.

Please refer to fig. 7. In other embodiments, two gauge pressure holes 19 may be provided to reduce the risk of the waterproof breathable membrane 20 being blocked by liquid such as water from below. Wherein two gage pressure ports 19 may be aligned in a first direction perpendicular to the longitudinal direction and separated by a partition beam 101 of the main casing 1.

In other embodiments, it may be preferred that a plurality of fisheye pins be embedded in the housing, for example, three first fisheye pins 151 and one second fisheye pin 152 may be included. Wherein, three first fisheye pins 151 and three second fisheye pins 152 can be respectively located at two opposite sides in the transverse direction. A plurality of pin holes 14 are correspondingly formed on the circuit board 13. One end of first fisheye pin 151 and one end of second fisheye pin 152 face upwards and are correspondingly clamped in the pin holes 14. The three first fisheye pins 151 are arranged in a first direction (a direction perpendicular to the paper in fig. 3) perpendicular to the longitudinal direction. Pin holes 14 are made by making holes in the circuit board and plating metal into the holes to simultaneously achieve mechanical and electrical connection with the fisheye pins. The circuit board is preferably a ceramic board.

In other embodiments, the main housing 1 is further connected with a button 2 at one end in the transverse direction, and the other ends of three of the buttons extend into the button 2. One of the first fisheye pins 151 passes through a portion of the housing (the dividing beam 101) located between the two gage pressure ports 19, and the other two first fisheye pins 151 pass through portions of the housing located on opposite sides of the two gage pressure ports 19, respectively.

Please refer to fig. 2. In other embodiments, in order to enable water to be discharged more smoothly from below the waterproof air-permeable membrane 20, a drainage groove 27 is formed by recessing inward at a proximal edge of one longitudinal side surface (lower surface in fig. 3) of the main casing 1. The edge of one side surface of the main casing 1 in the longitudinal direction protrudes outward to form a ring of flange 26, the middle of one side surface of the main casing 1 in the longitudinal direction protrudes outward to form a joint pipe mounting part 30, and the pressure joint pipe 3 is connected to the joint pipe mounting part 30. Preferably, the lower end of the main housing 1 and the flange 26 are rectangular, and at least two of the four corners of the flange 26 are provided with drain ports 23 communicating with the drain grooves 27.

In other embodiments, it is preferable that two convex portions 25 are formed on one longitudinal side surface of the main housing 1 to be convex outward with respect to the drain groove 27. The two protruding portions 25 are respectively located on the opposite sides of the two gauge pressure holes 19, so that the portion of the main housing 1 for installing the waterproof breathable film 20 can be bent during installation or use, and the risk of water leakage and even falling of the waterproof breathable film 20 is reduced. Preferably, the protrusion 25 is flush with a longitudinal side of the flange 26 in a transverse plane (e.g., the bottom surface 24 in fig. 5 and 6) perpendicular to the longitudinal direction.

In other embodiments, a plurality of longitudinally extending locating studs 16 are secured to the main housing 1. The positioning rivet 16 is riveted on the circuit board 13 after penetrating the circuit board 13 towards one longitudinal end of the housing. Preferably, the positioning studs 16 are integrally connected to the main housing 1 and may be made of plastic, which may be heat staked to the circuit board. The circuit board 13 can be securely held in the housing by locating the studs 16 and the fisheye pins. In other embodiments, the separator assembly may include a base plate 10 and a sealing gasket 8. A support surface 6 is formed on the inner wall of one longitudinal side of the housing. The base plate 10 presses the sealing gasket 8 against the support surface 6. Like this, the gauge pressure sensor of this application can guarantee to seal under the good prerequisite, can carry out very conveniently and assemble.

In other embodiments, in order to improve the sealing effect and prevent the lateral movement of the sealing gasket 8, the support surface 6 is provided with a ring of ribs 7, the ribs 7 being pressed into the sealing gasket 8.

In other embodiments, it is preferable that the inner wall of one longitudinal side of the main housing 1 is recessed to form a first mounting groove. The support surface 6 may be provided at the bottom of the first mounting groove.

In other embodiments, it is preferable that the opposite end of the above-mentioned one lateral end of the main housing 1 is provided with a longitudinally extending guide portion 29 which can be engaged with a guide structure (e.g., a guide groove) on the working device for positioning and guiding when the pressure joint pipe 3 is mounted on the working device.

In other embodiments, the pressure connector tube 3 is preferably sleeved with a sealing ring 5.

In other embodiments, it is preferable that the opposite side of the longitudinal side of the main housing 1 is recessed inward to form a second mounting groove. The edge of the cover 17 is protruded toward the opposite side of the longitudinal one side and abuts against the bottom of the second mounting groove. A glue groove 171 can be enclosed between the outer wall of the cover 17 and the side wall of the second mounting groove, so that glue can be poured into the glue groove 171, and the cover 17 and the main housing 1 can be bonded.

In other embodiments, the cover 17 may be recessed on its inner wall to form a plurality of relief recesses 18 for corresponding relief of fisheye pins, thereby minimizing the longitudinal dimension of the gauge pressure sensor.

In other embodiments, the circuit board 13 is provided with a window in the middle, and the pressure chip 12 is located in the window. The window is filled with a cover gel 28, such as silicone gel or fluorosilicone gel, which protects the pressure chip 12 from being covered while allowing pressure conduction with less loss.

In other embodiments, the aperture is a stepped bore having a step face facing an opposite side of the longitudinal side, the step face having the land provided thereon. The pressure chip 12 is connected to the bonding pads by wires 22, which facilitates the connection of the pressure chip 12 to the circuit board.

In other embodiments, the main housing 1, the connector mounting portion 30, the button 2, the pressure connector 3, and the guiding portion 29 may be integrally connected, for example, integrally formed by injection molding.

The scope of the present disclosure is defined not by the detailed description but by the claims and their equivalents, and all modifications within the scope of the claims and their equivalents are to be construed as being included in the present disclosure.

Claims

1. A gauge pressure sensor, comprising:

a housing;

the separating component is used for separating the inner cavity of the shell into a first cavity and a second cavity, the separating component is provided with a through hole for communicating the first cavity with the second cavity, and the second cavity is communicated to the outside of the shell through a gauge pressure hole (19) formed in one longitudinal side of the shell;

a pressure chip (12) having a pressure sensing surface for sealing the through hole from the opposite side of the longitudinal side of the second cavity;

the circuit board (13) is arranged in the second cavity and connected with the pressure chip (12);

and a pressure joint pipe (3) connected to the longitudinal side of the housing and communicated to the second chamber.

2. A gauge pressure sensor according to claim 1, wherein a waterproof, breathable membrane (20) is mounted at the gauge pressure port (19).

3. The gauge pressure sensor according to claim 2, wherein the waterproof breathable film (20) is installed at one end of the inner side of the gauge pressure hole (19), a heightening frame (21) is arranged between the waterproof breathable film (20) and the inner wall of the shell, and/or a circle of enclosing and/or glue separating grooves are arranged on the shell and are positioned around the waterproof breathable film (20).

4. A gauge pressure sensor according to claim 3, wherein there are two gauge pressure ports (19), and two of the gauge pressure ports (19) are arranged therebetween in a first direction perpendicular to the longitudinal direction.

5. The gauge pressure sensor according to claim 1, wherein a plurality of fisheye pins are fixed in the housing, a plurality of pin holes (14) are correspondingly formed in the circuit board (13), and one ends of the fisheye pins are correspondingly clamped in the pin holes (14).

6. The gauge pressure sensor according to claim 5, wherein the gauge pressure holes (19) are two, and two of the gauge pressure holes (19) are arranged therebetween in a first direction perpendicular to the longitudinal direction; the three fisheye pins are arranged along a first direction perpendicular to the longitudinal direction, one fisheye pin penetrates through the part, located between the two gauge pressure holes (19), of the shell, and the other two fisheye pins penetrate through the part, located on the opposite side of the two gauge pressure holes (19), of the shell respectively.

7. A gauge pressure sensor according to claim 1, wherein the housing is provided with a ring of drain grooves (27) formed by inwardly recessing an edge of the longitudinal side surface of the housing, and a ring of flanges (26) formed by relatively outwardly protruding an edge of the longitudinal side surface of the housing, and drain openings (23) communicating with the drain grooves (27) are provided at corners of the flanges (26).

8. The gauge pressure sensor according to claim 7, wherein the longitudinal side surface of the housing is formed with two protrusions (25) protruding outward with respect to the drain groove (27), and the two protrusions (25) are located on opposite sides of the gauge pressure holes (19), respectively.

9. A gauge pressure sensor according to claim 8, wherein the boss (25) is flush with the longitudinal side of the flange (26) in a transverse plane.

10. Gauge pressure sensor according to any of claims 1 to 9, characterized in that the pressure connector tube (3) extends longitudinally.