阅读说明：本技术 一种紧凑型压力感应模块 (Compact pressure sensing module ) 是由 唐田 朱建 刘庆 杨小华 于 2021-07-15 设计创作，主要内容包括：本发明公开了一种紧凑型压力感应模块,包括由两个膜座左右对焊连接、并将测量膜片固定夹持在中间形成的膜片式压力传感器,其外壁呈圆盘状,并且外罩设有封闭的稳压盒,稳压盒为空心圆柱形,稳压盒的两端部分别正对膜片式压力传感器的两端,稳压盒的圆周壁围绕膜片式压力传感器的圆周外壁,稳压盒与膜片式压力传感器之间的空间形成稳压腔,稳压盒的两端内壁与膜片式压力传感器的相应端面外壁之间分别设有抵靠限位结构,该抵靠限位结构之外的稳压腔为连续腔体。与现有技术相比,本发明的有益效果：通过简洁地结构将膜片式压力传感器方便地定位在稳压盒内,提高二者安装稳定性,同时稳压盒对两个膜座起到抵靠约束作用。(The invention discloses a compact pressure sensing module, which comprises a diaphragm type pressure sensor formed by connecting two diaphragm seats in a left-right butt welding mode and fixedly clamping a measuring diaphragm in the middle, wherein the outer wall of the diaphragm type pressure sensor is disc-shaped, a closed pressure stabilizing box is arranged on an outer cover of the diaphragm type pressure sensor, the pressure stabilizing box is hollow cylindrical, two end parts of the pressure stabilizing box are respectively opposite to two ends of the diaphragm type pressure sensor, the circumferential wall of the pressure stabilizing box surrounds the circumferential outer wall of the diaphragm type pressure sensor, a pressure stabilizing cavity is formed in a space between the pressure stabilizing box and the diaphragm type pressure sensor, abutting limiting structures are respectively arranged between the inner walls of two ends of the pressure stabilizing box and the outer walls of the corresponding end faces of the diaphragm type pressure sensor, and the pressure stabilizing cavity outside the abutting limiting structures is a continuous cavity. Compared with the prior art, the invention has the beneficial effects that: through succinctly the structure with diaphragm formula pressure sensor conveniently fix a position in the steady voltage box, improve the two installation stability, the steady voltage box plays to support to lean on the constraint effect to two membrane seats simultaneously.)

1. A compact pressure sensing module, comprising a diaphragm pressure sensor (100), wherein the diaphragm pressure sensor (100) comprises two diaphragm bases (110) and a measuring diaphragm (120), wherein two diaphragm bases (110) are butt welded left and right and the measuring diaphragm (120) is fixedly clamped to form the diaphragm pressure sensor (100) with a disc-shaped outer wall, characterized in that:

a closed pressure stabilizing box (200) is arranged outside the diaphragm type pressure sensor (100), the pressure stabilizing box (200) is in a hollow cylindrical shape, two end parts of the pressure stabilizing box (200) are respectively opposite to two ends of the diaphragm type pressure sensor (100), the circumferential wall of the pressure stabilizing box (200) surrounds the circumferential outer wall of the diaphragm type pressure sensor (100), and a space between the pressure stabilizing box (200) and the diaphragm type pressure sensor (100) forms a pressure stabilizing cavity (230);

abutting limiting structures are respectively arranged between the inner walls of the two ends of the pressure stabilizing box (200) and the outer walls of the corresponding end faces of the diaphragm type pressure sensor (100), and the pressure stabilizing cavity (230) outside the abutting limiting structures is a continuous cavity.

2. The compact pressure sensing module of claim 1, wherein: the areas of the two end faces of the diaphragm type pressure sensor (100) outside the occupied space of the abutting limiting structure are equal.

3. The compact pressure sensing module of claim 1, wherein: the abutting limiting structures at the two ends of the diaphragm type pressure sensor (100) are right and left opposite.

4. A compact pressure sensing module according to any one of claims 1 to 3, wherein: the abutting limiting structure comprises a positioning boss (111) and a positioning recess (221) which are matched with each other, one of the positioning boss and the positioning recess is located on the end face of the diaphragm type pressure sensor (100), and the other positioning boss and the positioning recess are located on the inner wall of the end portion of the pressure stabilizing box (200).

5. The compact pressure sensing module of claim 4, wherein: the diaphragm type pressure sensor is characterized in that the positioning bosses (111) are located on the end face of the diaphragm type pressure sensor (100), at least two positioning bosses (111) are arranged on each end face of the diaphragm type pressure sensor (100), all the positioning bosses (111) on the same end face of the diaphragm type pressure sensor (100) are evenly distributed around the center of the end face in the circumferential direction, and positioning recesses (221) are respectively arranged on the inner wall of the end portion of the pressure stabilizing box (200) corresponding to each positioning boss (111).

6. The compact pressure sensing module of claim 4, wherein: each end face of the diaphragm pressure sensor (100) is provided with at least two arc-shaped positioning bosses (111), the positioning bosses (111) on the same end face are positioned on the same circular ring, and the positioning bosses (111) on the same end face are uniformly distributed around the cylindrical center line of the diaphragm pressure sensor (100) in the radial direction;

the inner area and the outer area of a circular ring formed by surrounding all the positioning bosses (111) are communicated through gaps among the positioning bosses (111) on the same end face.

7. The compact pressure sensing module of claim 4, wherein: the pressure stabilizing box (200) comprises a cylinder (210), the cylinder (210) is sleeved outside the diaphragm type pressure sensor (100), two ends of the cylinder (210) are respectively buckled and covered with a circular end plate (220), and the cylinder (210) is respectively welded with the two circular end plates (220);

the inner side surfaces of the two circular end plates (220) are respectively provided with the positioning depressions (221).

Technical Field

The invention relates to a pressure measuring device, in particular to a compact pressure sensing module.

Background

The detection principle of the flowmeter for detecting the fluid flow is to detect the pressure values of two different points on a fluid flow path, and the fluid flow can be calculated due to the difference of the pressure values of the two points. The main body of this type of flowmeter is a fluid pressure detection device, and the core detection element of the fluid pressure detection device is a diaphragm pressure sensor. The diaphragm type pressure sensor converts two pressure signals of different positions of fluid into the change of a capacitance signal, and then a detection circuit at the rear end processes the change of the capacitance signal to obtain a differential pressure value of applied pressure.

The diaphragm type pressure sensor comprises two cake-shaped diaphragm seats, a measuring diaphragm is arranged between the two diaphragm seats, and the two diaphragm seats are in butt welding connection and clamp the measuring diaphragm tightly. Pressure transmission cavities for containing liquid pressure transmission media are arranged between the measuring diaphragm and the two diaphragm seats respectively, the two pressure transmission cavities are connected with pressure transmission channels respectively, external pressure to be measured is introduced into the two sides of the measuring diaphragm, and the deformation of the measuring diaphragm is reflected as the change of capacitance signals.

The diaphragm type pressure sensor is connected with the pressure taking module, and the fluid pressure is transmitted to the measuring diaphragm through the pressure taking module. Due to the fact that volume change is extremely tiny when liquid is pressurized, when high-pressure fluid is measured, the internal pressure of a pressure transmission cavity is remarkably increased, two membrane seats have the tendency of outward expansion deformation and mutual separation, welding seams can be cracked when the two membrane seats work for a long time in a high-pressure state, and the diaphragm type pressure sensor is caused to lose effectiveness in an accelerated mode. For this reason, patent document CN112595450A discloses a sealed pressure stabilizing structure for a pressure sensor, in which after a diaphragm sensor is mounted on a pressure-leading seat, a cover body is used to cover the diaphragm sensor, the cover body is hermetically connected with the pressure-leading seat to form a sealed pressure stabilizing cavity, silicone oil is filled in the pressure stabilizing cavity, and the pressure stabilizing cavity and one of the pressure transmitting cavities are connected with the same external pressure source, so as to form a pressure balancing system. Therefore, the external pressure acts on the inside and the outside of the diaphragm type pressure sensor simultaneously, so that the internal pressure and the external pressure are balanced when the sensor works, and the sensor is protected. However, there are problems with this structure. Firstly, the pressure stabilizing cavity has a large volume, consumes more silicone oil, increases the cost, and simultaneously brings challenges to the assembly and sealing between the cover body and the pressure guiding seat. More importantly, in order to simplify the structure, the pressure stabilizing cavity is directly communicated with one pressure transmission cavity in actual design so as to ensure synchronous change of internal and external pressures of the sensor, but the volume change cannot be ignored when the silicon oil is more and expands under heat, so that the silicon oil in the pressure transmission cavity on one side connected with the pressure stabilizing cavity has obvious pressure change on the measuring diaphragm, and the accuracy of the sensor is also influenced. For this reason, it is necessary to further improve the pressure balance system inside and outside the sensor and the corresponding structure.

Disclosure of Invention

In view of the above, the present invention provides a compact pressure sensing module as part of an overall solution to the above-mentioned problems.

The technical scheme is as follows:

a compact pressure sensing module comprises a diaphragm pressure sensor, the diaphragm pressure sensor comprises two diaphragm seats and a measuring diaphragm, wherein the two diaphragm seats are in butt welding connection left and right and fixedly clamp the measuring diaphragm to form the diaphragm pressure sensor with a disc-shaped outer wall,

the diaphragm type pressure sensor is characterized in that a closed pressure stabilizing box is arranged on the outer cover of the diaphragm type pressure sensor, the pressure stabilizing box is hollow cylindrical, two end parts of the pressure stabilizing box are respectively opposite to two ends of the diaphragm type pressure sensor, the circumferential wall of the pressure stabilizing box surrounds the circumferential outer wall of the diaphragm type pressure sensor, and a pressure stabilizing cavity is formed in a space between the pressure stabilizing box and the diaphragm type pressure sensor;

and abutting limit structures are respectively arranged between the inner walls of the two ends of the pressure stabilizing box and the outer walls of the corresponding end surfaces of the diaphragm type pressure sensors, and the pressure stabilizing cavity outside the abutting limit structures is a continuous cavity.

Compared with the prior art, the invention has the beneficial effects that: through succinctly the structure with diaphragm formula pressure sensor conveniently fix a position in steady voltage box, improve the two installation stability, steady voltage box plays two membrane seats to diaphragm formula pressure sensor simultaneously and supports to lean on the constraint effect, prevents that the two from welding seam department part relatively.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of a positioning boss on the end face of the diaphragm pressure sensor, in which a partial structure of the pressure stabilizing box is hidden;

FIG. 3 is a schematic cross-sectional view of a measurement module;

FIG. 4 is a schematic view of the overall structure of the measurement module;

FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4;

FIG. 6 is a left side view of FIG. 4;

fig. 7 is a cross-sectional view taken along line C-C of fig. 6.

Detailed Description

The present invention will be further described with reference to the following examples and the accompanying drawings.

Example 1

As shown in fig. 1, a compact pressure sensing module includes a diaphragm pressure sensor 100, where the diaphragm pressure sensor 100 includes two diaphragm bases 110 and a measuring diaphragm 120, where the two diaphragm bases 110 are butt-welded to each other left and right, and the measuring diaphragm 120 is fixedly clamped to form the diaphragm pressure sensor 100 with a disk-shaped outer wall. The diaphragm pressure sensor 100 is covered with a closed pressure stabilizing box 200, the pressure stabilizing box 200 is hollow cylindrical, two ends of the pressure stabilizing box 200 are respectively opposite to two ends of the diaphragm pressure sensor 100, the circumferential wall of the pressure stabilizing box 200 surrounds the circumferential outer wall of the diaphragm pressure sensor 100, and a pressure stabilizing cavity 230 is formed in the space between the pressure stabilizing box 200 and the diaphragm pressure sensor 100. Abutting limit structures are respectively arranged between the inner walls of the two ends of the pressure stabilizing box 200 and the outer walls of the corresponding end surfaces of the diaphragm type pressure sensor 100, and the pressure stabilizing cavity 230 outside the abutting limit structures is a continuous cavity.

The measuring diaphragm 120 and the two diaphragm holders 110 respectively form a pressure transmission cavity, the two pressure transmission cavities are respectively connected with a pressure guiding pipe 130, and the pressure transmission cavities and the pressure guiding pipe 130 are filled with liquid pressure transmission media for transmitting the pressure of the fluid to be measured to the measuring diaphragm 120. The two pressure pipes 130 respectively penetrate through the pressure stabilizing box 200, and the pipe walls of the two pressure pipes 130 are respectively sealed with the wall of the pressure stabilizing box 200. The pressure stabilizing cavity 230 is used for accommodating liquid pressure transmission medium, and the liquid pressure transmission medium can fill the whole pressure stabilizing cavity 230 due to the fact that the pressure stabilizing cavity is a continuous cavity. The pressure stabilizing cavity 230 is connected with a pressure source through a liquid pressure transmission medium or is communicated with any one of the pressure leading pipes 130. In this way, the pressure of the fluid to be measured is transmitted to the inside and the outside of the diaphragm pressure sensor 100 at the same time, thereby achieving the balance of the internal and external pressures. In the embodiment, a skillful and simple structure is adopted, that is, a communication port 140 is formed in the tube wall of the section of one of the pressure guiding tubes 130 corresponding to the pressure stabilizing cavity 230, and the pressure guiding tube 130 is communicated with the pressure stabilizing cavity 230 through the communication port 140.

In order to make the liquid pressures on the two end faces of the diaphragm pressure sensor 100 the same, the areas of the two end faces of the diaphragm pressure sensor 100 outside the occupied space of the abutting limiting structure are equal. Further, the abutting limiting structures at two ends of the diaphragm type pressure sensor 100 are right and left opposite and symmetrical with respect to the measuring diaphragm 120. Thus, the liquid pressure received by both end faces of the diaphragm type pressure sensor 100 and the abutting force from the surge tank 200 are uniform and symmetrical.

The abutting limiting structure comprises a positioning boss 111 and a positioning recess 221 which are matched with each other, wherein one of the positioning boss and the positioning recess is positioned on the end face of the diaphragm type pressure sensor 100, and the other one is positioned on the inner wall of the end part of the pressure stabilizing box 200.

In this embodiment, the positioning bosses 111 are located on the end surface of the diaphragm pressure sensor 100, at least two positioning bosses 111 are arranged on each end surface of the diaphragm pressure sensor 100, all the positioning bosses 111 located on the same end surface of the diaphragm pressure sensor 100 are circumferentially and uniformly distributed around the center of the end surface, and the inner wall of the end portion of the pressure stabilizing box 200 corresponding to each positioning boss 111 is respectively provided with a positioning recess 221.

In order to make the abutting force of the pressure stabilizing box 200 on the end face of the diaphragm pressure sensor 100 as uniform as possible. As shown in fig. 2, each end face of the diaphragm pressure sensor 100 is provided with at least two arc-shaped positioning bosses 111, the positioning bosses 111 on the same end face are located on the same ring, and the positioning bosses 111 on the same end face are uniformly distributed around the cylindrical core of the diaphragm pressure sensor 100 in the axial direction. In this embodiment, there are two positioning bosses 111 on the same end surface. The inner area and the outer area of the circular ring surrounded by all the positioning bosses 111 are communicated through the gaps between the positioning bosses 111 on the same end surface to form a channel for flowing of liquid pressure transfer medium. Thus, the pressure guiding tube 130 connected to the pressure transmitting cavity on the same side of the end face of the measuring diaphragm 120 penetrates out of the circular ring surrounded by the positioning boss 111.

In one embodiment, the pressure stabilizing box 200 includes a cylinder 210, the cylinder 210 is sleeved outside the diaphragm pressure sensor 100, two ends of the cylinder 210 are respectively covered with a circular end plate 220, and the cylinder 210 and the two circular end plates 220 are respectively welded and connected. The inner side surfaces of the two circular end plates 220 are respectively provided with a positioning recess 221.

The compact pressure sensing module is applied to the following measuring module of the flowmeter.

Example 2

Referring to fig. 3, a measurement module of a flow meter includes the above-mentioned compact pressure sensing module, and further includes a pressure-inducing seat 300 and a pressure-tapping seat 400. The upper surface of the pressure guide base 300 is provided with a positioning groove 310, the bottom of the positioning groove 310 is an arc surface with an upward concave surface, the pressure stabilizing box 200 is arranged in the positioning groove 310, the lower part of the pressure stabilizing box 200 is located in the positioning groove 310, the cylinder 210 falls on the bottom of the positioning groove 310, and the two circular end plates 220 are respectively close to the two side groove walls of the positioning groove 310. The pressure guide base 300 is further provided with two pressure guide channels 320, the two pressure guide channels 320 are respectively located at two sides of the positioning groove 310, and the two pressure guide channels 320 are in one-to-one correspondence with and connected to the two pressure guide pipes 130.

As can be seen from fig. 4 and 5, the pressure guiding channel 320 includes a horizontal pressure guiding section and a vertical pressure guiding section, wherein the upper end of the vertical pressure guiding section is connected to the corresponding pressure guiding pipe 130, the lower end of the vertical pressure guiding section is connected to one end of the horizontal pressure guiding section, and the other end of the horizontal pressure guiding section is open on the outer sidewall of the pressure guiding base 300. The outer wall of the pressure guiding base 300 is provided with pressure guiding ports 330 corresponding to the two horizontal pressure guiding sections, the pressure guiding ports 330 are variable diameter holes, the diameter of the holes is gradually reduced from outside to inside, and the inner ends of the pressure guiding ports 330 are communicated with the outer ends of the horizontal pressure guiding sections. The outer end of the pressure guide port 330 is covered with an isolation diaphragm 340, the isolation diaphragm 340 closes the outer end of the pressure guide port 330, so that one of the pressure transmission cavities, the pressure guide pipe 130, the pressure guide channel 320 and the pressure guide port 330 connected with the pressure transmission cavity form a closed liquid containing cavity, and the other pressure transmission cavity, the pressure guide pipe 130, the pressure guide channel 320, the pressure guide port 330 and the pressure stabilizing cavity 230 connected with the pressure transmission cavity form another closed liquid containing cavity. Every draws and presses the passageway 320 to be connected with and annotates the liquid hole, annotates the one end in liquid hole and the corresponding passageway 320 intercommunication of drawing the pressure, and the other end opening is in drawing the surface of pressing the seat 300, and the outer end of annotating the liquid hole is equipped with can dismantle the end cap. The liquid injection holes are used for respectively filling liquid pressure transfer media which can be silicon oil into the corresponding liquid containing cavities.

As can be seen from fig. 4 to 7, the openings of the two pressure guiding openings 330 are oppositely arranged on a pair of opposite parallel side walls of the pressure guiding base 300, one pressure taking base 400 is respectively arranged on the side wall of the pressure guiding base 300 where the pressure guiding opening 330 is located, and the two pressure taking bases 400 are connected with the pressure guiding base 300 through bolts. Each pressure taking seat 400 is further provided with a pressure taking channel 410 and a pressure taking hole 420, wherein the pressure taking channel 410 is communicated with the pressure taking hole 420, the pressure taking hole 420 is formed in the side wall of the pressure taking seat 400 facing the pressure drawing seat 300, the pressure taking hole 420 is opposite to the corresponding pressure drawing port 330, and a pressure taking area is formed in the area between the pressure taking hole 420 and the corresponding isolation diaphragm 340.

As shown in fig. 1, signal leads 150 are respectively led out from two sides of the measuring diaphragm 120, two signal leads 150 are also respectively led out from two diaphragm seats 110 in a sealed manner, and a lead via hole is opened on each circular end plate 220 corresponding to the corresponding signal lead 150. The outer wall of each circular end plate 220 is integrally formed with a connector tube 250. The lead via hole has a hole center line with the corresponding connector tube 250, and the hole diameter of the lead via hole is smaller than the inner diameter of the connector tube 250. A lead wire connector 260 is embedded in the wire connector tube 250, the signal lead 150 is arranged in the lead wire connector 260 and the lead through hole in a penetrating manner, and the lead wire connector 260 seals the lead through hole. Two signal leads 150 conduct the capacitance change signal to the detection circuitry to detect pressure changes within the pressure transmitting chamber.

During measurement, the two pressure taking channels 410 are respectively connected with two points on the fluid flow path, fluid at two different points enters the corresponding pressure taking areas, fluid pressure acts on the corresponding isolation diaphragm 340 and is conducted to the measurement diaphragm 120 through the liquid pressure transmission medium, and therefore the fluid pressure at two positions is measured, and the fluid flow is calculated.

Finally, it should be noted that the above-mentioned description is only a preferred embodiment of the present invention, and those skilled in the art can make various similar representations without departing from the spirit and scope of the present invention.