Differential pressure sensor

Abstract

The utility model relates to the technical field of pressure detection, and discloses a differential pressure transducer, which comprises a shell, an installation groove is arranged in the shell, a first detection groove and a second detection groove are arranged in the installation groove, and a first gas transmission channel communicated with the first detection groove and a second gas transmission channel communicated with the second detection groove are arranged on the shell. The bottom of the PCB is provided with two MEMS chips, the bottom surface of the PCB is provided with a box dam at the periphery of each MEMS chip, and the box dam is provided with a third gas transmission channel; the PCB is installed in the installation groove, the two box dams are installed in the first detection groove and the second detection groove in a sealed mode through adhesive layers respectively, and gas input from the first gas transmission channel and the second gas transmission channel is input into the MEMS chip through the third gas transmission channel. When the pressure detection device is used, the two MEMS chips are arranged, and the two MEMS chips can detect the pressure at the two ends of the particle trap through the first gas transmission channel and the second gas transmission channel, so that the pressure detection can be more accurately carried out.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure detection, in particular to a differential pressure sensor. Background Art

[0002] At present, pressure sensors are needed for pressure detection in the fields of monitoring and control of hydraulic, pneumatic and hydraulic systems in the industrial field, blood vessel and nerve pressure detection in the medical field, tire pressure detection in automobiles, overload detection of particle collectors, and aerospace. In these detection fields, the pressure detection sensor converts the pressure into an electrical signal through the MEMS chip on the one hand, and processes the electrical signal through the signal processing circuit on the other hand to obtain the final pressure detection signal. Therefore, when performing pressure detection, on the one hand, the sealing of the MEMS chip and the gas pipeline must be ensured, and on the other hand, the influence of the detection environment on the signal processing circuit must be avoided.

[0003] Taking the overload detection of the particulate filter of a car as an example, the first thing you need to know is that since the internal combustion engine works by burning petroleum fuel, the fuel will produce harmful substances such as nitrogen oxides, hydrocarbons, sulfides and particulate matter during the combustion process. If these harmful substances are not treated, they will seriously affect the environment and cause pollution to the environment. In order to prevent the above pollutants from being discharged into the environment, three-way catalysis (TWC) and selective catalytic reduction technology (SCR) will be used to remove nitrogen oxides, hydrocarbons, sulfides and other harmful substances, so that the car can meet the latest National VI B emission standards in my country; however, since particulate matter cannot be removed fundamentally, it can only be "captured" and then removed using regeneration technology. Specifically, a differential pressure sensor is used to detect the pressure at both ends of the catalyst to determine whether the particulate filter (DPF / GPF) is overloaded, and the regeneration technology is triggered when the particulate filter is overloaded.

[0004] However, the existing differential pressure sensors have the following deficiencies in actual use:

[0005] First, a single MEMS chip is used to detect the pressure at both ends of the catalyst, which has low detection accuracy;

[0006] Secondly, other components on the PCB board where the MEMS chip is installed will be exposed to automobile exhaust, thereby corroding the electronic components and reducing the product life. That is, the existing pressure sensor cannot well seal and isolate the pressure detection surface of the MEMS chip and the components on the PCB board;

[0007] Finally, the consistency of the sealing layer of the PCB board cannot be controlled, and there is a risk of leakage. Utility Model Content

[0008] In view of the shortcomings of the background technology, the utility model provides a differential pressure sensor. The technical problem to be solved is that the existing differential pressure sensor used to determine whether the secondary particulate collector is overloaded has the problems of low detection accuracy, components corroded by exhaust gas and poor sealing consistency of PCB board.

[0009] In order to solve the above technical problems, the utility model provides the following technical solutions: a differential pressure sensor, comprising

[0010] A housing, wherein a mounting groove is provided inside the housing, a first detection groove and a second detection groove are provided inside the mounting groove, and a first gas transmission channel communicating with the first detection groove and a second gas transmission channel communicating with the second detection groove are provided on the housing;

[0011] A PCB board, wherein two MEMS chips are arranged at the bottom of the PCB board, a dam is arranged at the periphery of each MEMS chip on the bottom surface of the PCB board, and a third gas transmission channel is arranged on the dam in a direction perpendicular to the PCB board;

[0012] The PCB board is installed in the installation groove, and two dams are respectively installed in the first detection groove and the second detection groove through adhesive layer sealing, and the gas input from the first gas transmission channel and the second gas transmission channel is input to the MEMS chip through the third gas transmission channel.

[0013] In some embodiments, the gas outlet of the first gas transmission channel extends to the bottom of the first detection tank, and the gas outlet of the second gas transmission channel extends to the bottom of the second detection tank.

[0014] In a certain embodiment, the bottom of the first detection groove is provided with a first protrusion outside the gas outlet of the first gas transmission channel, and the bottom of the second detection groove is provided with a second protrusion outside the gas outlet of the second gas transmission channel; the two dams are respectively mounted on the first protrusion and the second protrusion.

[0015] In a certain embodiment, four support columns are provided on the bottom surface of the mounting groove, and the PCB board is sleeved on the four support columns.

[0016] In a certain embodiment, the four support columns are distributed in a rectangular shape inside the installation slot, two support columns are located on both sides of the first detection slot, and the other two support columns are located on both sides of the second detection slot.

[0017] In a certain embodiment, an opening is provided on the top of the shell, and an upper cover is installed on the top of the shell, and the upper cover covers the opening.

[0018] In some embodiments, the air inlet of the first air delivery channel and the air inlet of the second air delivery channel are located on the same side of the shell.

[0019] In a certain embodiment, an electrical connector is also installed on the shell, and an electrical terminal is provided inside the electrical connector, and the electrical terminal is electrically connected to the signal terminal on the PCB board.

[0020] In a certain embodiment, a fixing seat is provided on one side of the shell, and a fixing hole is opened on the fixing seat along the vertical direction.

[0021] In a certain embodiment, the third gas transmission channel is stepped, and the end with a smaller opening faces the MEMS chip.

[0022] Compared with the prior art, the utility model has the following beneficial effects: firstly, by setting two MEMS chips, and allowing the two MEMS chips to detect the pressure at both ends of the particle trap through the first gas transmission channel and the second gas transmission channel, the pressure detection can be performed more accurately;

[0023] Secondly, by setting the first inspection slot and the second inspection slot, and allowing the two dams to be installed in the first inspection slot and the second inspection slot through the adhesive layer, it can be ensured that the air outlet of the first gas pipeline and the air outlet of the second gas pipeline are sealed with the periphery of the dam, thereby improving the sealing consistency and isolating the automobile exhaust from corroding other components on the PCB board. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure in which the PCB board in the embodiment is installed in the housing;

[0025] Figure 2 is a schematic structural diagram of a housing in an embodiment;

[0026] Figure 3 Schematic diagram of the structure of the PCB board in the embodiment;

[0027] Figure 4 for Figure 1 Schematic diagram of the internal section of the structure in the longitudinal direction;

[0028] Figure 5 for Figure 1 Schematic diagram of the internal cross-section of the structure in the transverse direction. DETAILED DESCRIPTION

[0029] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0030] like Figure 1-3 As shown, a differential pressure sensor includes

[0031] Shell 1, wherein the structure of shell 1 refers to Figure 2 The housing 1 is provided with a mounting groove 14, the first detection groove 12 and the second detection groove 13 are provided inside the mounting groove 14, and the housing 1 is provided with a first gas delivery channel 10 communicating with the first detection groove 12 and a second gas delivery channel 11 communicating with the second detection groove 13;

[0032] PCB board 2, wherein the structural schematic diagram of PCB board 2 is as follows Figure 3 As shown, two MEMS chips 21 are arranged at the bottom of the PCB board 2, and a dam 22 is arranged on the bottom surface of the PCB board 2 at the periphery of each MEMS chip 21, and a third gas transmission channel 220 is arranged on the dam 22 in a direction perpendicular to the PCB board 2; in addition, the material of the PCB board 2 is a glass fiber board;

[0033] exist Figure 1 In the embodiment, the PCB board 2 is installed in the installation groove 14, and the two dams 22 are respectively installed in the first detection groove 12 and the second detection groove 13 through the adhesive layer sealing; Figure 4 and Figure 5 The gas input from the first gas transmission channel 10 and the second gas transmission channel 11 is input to the MEMS chip 21 through the third gas transmission channel 220 .

[0034] for Figure 1 The structure shown in the figure, by setting two MEMS chips 21, and allowing the two MEMS chips 21 to detect the pressure at both ends of the particle trap through the first gas transmission channel 10 and the second gas transmission channel 11, so that the pressure detection can be performed more accurately;

[0035] Secondly, by setting the first detection groove 12 and the second detection groove 13, and allowing the two dams 22 to be installed in the first detection groove 12 and the second detection groove 13 through the adhesive layer, it can be ensured that the air outlet 101 of the first gas pipeline 10 and the air outlet 111 of the second gas pipeline 11 are sealed with the periphery of the dam 22, thereby improving the sealing consistency and isolating the automobile exhaust from corroding other components on the PCB board 2.

[0036] Specifically, in this embodiment, Figure 1 In the embodiment, the air inlet 100 of the first air delivery channel 10 and the air inlet 110 of the second air delivery channel 11 are located on the same side of the housing 1. The air outlet 101 of the first air delivery channel 10 extends to the bottom of the first detection slot 12, and the air outlet 111 of the second air delivery channel 11 extends to the bottom of the second detection slot 13.

[0037] In addition, a first protrusion 130 is provided at the bottom of the first detection groove 12 outside the gas outlet 101 of the first gas transmission channel 10, and a second protrusion 131 is provided at the bottom of the second detection groove 13 outside the gas outlet 111 of the second gas transmission channel 11; the two dams 22 are respectively mounted on the first protrusion 130 and the second protrusion 131.

[0038] In actual use, the first protrusion 130 and the second protrusion 131 can be used to locate the position of the dam 22, which is convenient for installation. Figure 3 and Figure 5 In the figure, the third gas transmission channel 220 is stepped, and the end with a smaller opening faces the MEMS chip. By setting the third gas transmission channel 220 to a stepped shape, firstly, the step of the third gas transmission channel 220 can be located on the protrusion to prevent the protrusion from damaging the MEMS chip 21. Secondly, the material used for the dam 22 can be reduced. Finally, by setting an open dam 22, after the condensed water freezes, the open dam 22 can disperse the force formed by the volume expansion of the condensed water after freezing.

[0039] In addition, Figure 1 In the embodiment, four supports 5 are provided on the bottom surface of the mounting groove 14 , and the PCB board 2 is sleeved on the four support columns 2 .

[0040] Specifically, the four support columns 5 are distributed in a rectangular shape inside the installation slot 14, with two support columns 5 on both sides of the first detection slot 12 and the other two support columns 5 on both sides of the second detection slot 13. In actual use, the position of the PCB board 2 in the installation slot 14 can be ensured by the four support columns 5, so that the sealing consistency of the utility model can be better.

[0041] In addition, an opening 15 is provided on the top of the housing 1 , and an upper cover is installed on the top of the housing 1 , the upper cover covers the opening 15 , wherein the shape of the upper cover is set according to the shape of the opening 15 .

[0042] In addition, in this embodiment, an electrical connector 4 is also installed on the housing 1, and an electrical terminal 40 is provided inside the electrical connector 4, and the electrical terminal 40 is electrically connected to the signal terminal 20 on the PCB board 2. In actual use, the electrical connector 4 can realize signal interaction between the utility model and the external circuit.

[0043] In addition, in this embodiment, a fixing seat 3 is provided on one side of the housing 1, and a fixing hole 30 is opened in the vertical direction on the fixing seat 3. The fixing seat 3 and the electrical connector 4 are located on two opposite sides of the housing 1.

[0044] The above is based on the enlightenment of this utility model. Through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of ​​this utility model. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A differential pressure sensor, characterized in that: include A housing (1), wherein a mounting groove (14) is provided inside the housing (1), a first detection groove (12) and a second detection groove (13) are provided inside the mounting groove (14), and a first gas transmission channel (10) communicating with the first detection groove (12) and a second gas transmission channel (11) communicating with the second detection groove (13) are provided on the housing (1); A PCB board (2), wherein two MEMS chips (21) are provided at the bottom of the PCB board (2), a dam (22) is provided on the bottom surface of the PCB board (2) at the periphery of each MEMS chip (21), and a third gas transmission channel (220) is provided on the dam (22) in a direction perpendicular to the PCB board; The PCB board (2) is installed in the installation groove (14), and the two dams (22) are respectively installed in the first detection groove (12) and the second detection groove (13) through adhesive layer sealing, and the gas input from the first gas transmission channel (10) and the second gas transmission channel (11) is input into the MEMS chip (22) through the third gas transmission channel (220).

2. A differential pressure sensor according to claim 1, characterized in that: The gas outlet (101) of the first gas supply channel (10) extends to the bottom of the first detection groove (12), and the gas outlet (111) of the second gas supply channel (11) extends to the bottom of the second detection groove (13).

3. A differential pressure sensor according to claim 2, characterized in that: The bottom of the first detection groove (12) is provided with a first protruding portion (130) at the periphery of the gas outlet (101) of the first gas transmission channel (10), and the bottom of the second detection groove (13) is provided with a second protruding portion (131) at the periphery of the gas outlet (111) of the second gas transmission channel (11); the two dams (22) are respectively sleeved on the first protruding portion (130) and the second protruding portion (131).

4. A differential pressure sensor according to claim 1, characterized in that: Four support columns (5) are provided on the bottom surface of the installation groove (14), and the PCB board (2) is sleeved on the four support columns (5).

5. A differential pressure sensor according to claim 4, characterized in that: The four support columns (5) are distributed in a rectangular shape inside the installation slot (14), two support columns (5) are located on both sides of the first detection slot (12), and the other two support columns (5) are located on both sides of the second detection slot (13).

6. A differential pressure sensor according to claim 1, characterized in that: The top of the shell (1) is provided with an opening, and an upper cover is installed on the top of the shell, the upper cover covers the opening.

7. A differential pressure sensor according to claim 1, characterized in that: The air inlet (100) of the first air delivery channel (10) and the air inlet (110) of the second air delivery channel (11) are located on the same side of the housing (1).

8. The differential pressure sensor according to claim 1, characterized in that: An electrical connector (4) is also mounted on the housing (1), an electrical terminal (40) is provided inside the electrical connector (4), and the electrical terminal (40) is electrically connected to a signal terminal (20) on the PCB board (2).

9. The differential pressure sensor according to claim 1, characterized in that: A fixing seat (3) is provided on one side of the housing (1), and a fixing hole (30) is provided on the fixing seat (3) in a vertical direction.

10. The differential pressure sensor according to claim 1, characterized in that: The third gas transmission channel (220) is in a stepped shape, and the end with a smaller opening faces the MEMS chip.

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