A high-precision urea pump pressure sensor

Abstract

The utility model relates to pressure measurement sensing related technical field, concretely to a kind of high-precision urea pump pressure sensor, the lower end of shell body is provided with sensing connector;The surface of first cantilever plate is through and is provided with first reserved hole;The surface of second cantilever plate is through and is provided with second reserved hole;The sidewall of shell body is further provided with wire board;Wire hole is through and is provided between wire board and shell body;Lead terminal is mounted in the inside of wire hole;Positioning buckle is arranged on the inner side wall of wire board;The upper end of shell body is provided with upper cover;Upper cover and the upper surface of shell body are sealed together;Induction circuit is fixedly installed in upper mounting hole;Sensing groove is processed on sensing connector and sensing diaphragm is installed on the sensing groove, and sensing chip is installed on the upper portion of sensing diaphragm;The utility model can provide a kind of high-precision urea pump pressure sensor with corrosion resistance, anti-electromagnetic interference capability and strong use stability.

Description

Technical Field

[0001] This utility model belongs to the technical field of pressure measurement and sensing, and specifically relates to a high-precision urea pump pressure sensor. Background Technology

[0002] The urea pressure sensor feeds back the detected urea solution pressure signal to the engine controller (ECU), which then adjusts the urea solution injection pressure in real time according to the fuel injection requirements. This allows the nitrogen oxides in the vehicle exhaust to neutralize with the urea solution, eliminating nitrogen oxide pollution to the atmospheric environment.

[0003] In recent years, with the continuous advancement of environmental protection policies and the upgrading of vehicle exhaust treatment technologies, urea sensors, as a core component of diesel vehicle exhaust reprocessing (SCR) systems, have become an indispensable link in the environmental protection industry chain. Data shows that the global number of diesel vehicles is steadily increasing, and domestic and international standards for nitrogen oxide emissions from diesel vehicles are continuously tightening. With the full implementation of the China VI emission standard, SCR systems have become standard equipment for automakers. Each diesel vehicle needs to be equipped with 1-2 urea sensors, directly driving the incremental market demand for IoT devices. Existing sensors suffer from problems such as easy freezing, slow response speed, and low measurement accuracy. To solve the problems encountered in the detection process of urea pump pressure sensors, it is necessary to develop a new type of sensor device that can improve the accuracy of nitrogen oxide emission detection and help make diesel engines cleaner. Utility Model Content

[0004] The purpose of this invention is to provide a high-precision urea pump pressure sensor that is corrosion-resistant, electromagnetic interference-resistant, and has strong stability in use.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a high-precision urea pump pressure sensor, comprising a housing, a sensing connector, a first cantilever plate, a second cantilever plate, a first reserved hole, a second reserved hole, a wire guide plate, a wire hole, a lead terminal, a positioning buckle, and a top cover; the lower end of the housing is provided with a sensing connector; the left and right side walls of the housing are fixed with a first cantilever plate and a second cantilever plate; the surface of the first cantilever plate is provided with a first reserved hole; the surface of the second cantilever plate is provided with a second reserved hole; a wire guide plate is also provided on the side wall of the housing; a wire hole is provided between the wire guide plate and the housing; A lead terminal is installed inside the wire hole; a positioning buckle is provided on the inner side wall of the wire board; a top cover is provided at the upper end of the housing; the top cover is sealed to the upper surface of the housing; a first sealing ring is installed circumferentially on the outer side of the sensing connector; a second sealing ring is installed circumferentially on the inner side of the sensing connector; an upper mounting hole and a lower mounting hole are reserved inside the housing, and the sensing connector is inserted into the lower mounting hole, while a sensing circuit is fixedly installed in the upper mounting hole; a sensing groove is machined on the sensing connector, and a sensing diaphragm is installed on the sensing groove, with a sensing chip installed on the upper part of the sensing diaphragm.

[0006] As a further improvement of this utility model, a ceramic pad is provided at the edge of the sensing chip located above the sensing diaphragm; the gaps in the sensing grooves of the sensing connector are all filled with low-temperature filling oil.

[0007] As a further improvement of this utility model, the terminal of the sensing chip is provided with pins, and the pins are connected to the lead terminals through the sensing circuit via wires.

[0008] As a further improvement of this utility model, the gaps in the upper and lower mounting holes inside the outer shell are filled with sealant.

[0009] As a further improvement of this utility model, the sensing diaphragm is made of corrosion-resistant stainless steel corrugated diaphragm.

[0010] According to the high-precision urea pump pressure sensor of the claim, the filling oil is diffused silicon oil-filled, and the sensing chip is a diffused silicon oil-filled sensing chip.

[0011] As a further improvement of this utility model, the outer shell is made of nylon and glass fiber material.

[0012] As a further improvement of this utility model, both the first sealing ring and the second sealing ring are made of silicone double-layer O-rings.

[0013] Compared with existing technologies, the beneficial effects of this utility model are as follows: This device, through its compact structural design and the use of low-temperature resistant materials and components, can solve the problems encountered in the detection process of urea pump pressure sensors, including easy freezing, slow response speed, and low measurement accuracy, thereby improving the detection of nitrogen oxide emissions and contributing to cleaner diesel engines. This device also employs multi-layer sealing rings filled with sealant and low-temperature filling oil, which effectively improves its sealing performance and low-temperature resistance. Furthermore, the device incorporates a stainless steel corrugated diaphragm inside the sensing end, enhancing its corrosion resistance in harsh environments such as those with high concentrations of urea in diesel vehicles, effectively improving its service life and operational stability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the upper part of this utility model.

[0015] Figure 2 This is a schematic diagram of the overall structure of the lower part of this utility model.

[0016] Figure 3 This is a top view of the structure of this utility model.

[0017] Figure 4 This is a schematic diagram of the internal cross-section of the connection between the outer shell and the sensing connector of this utility model.

[0018] In the diagram: 1. Outer shell; 2. Sensor connector; 3. First cantilever plate; 4. Second cantilever plate; 5. First reserved hole; 6. Second reserved hole; 7. Wire board; 8. Wire hole; 9. Lead terminal; 10. Positioning buckle; 11. Top cover; 12. First sealing ring; 13. Second sealing ring; 14. Sensing circuit; 15. Sensing diaphragm; 16. Filling oil; 17. Sensor chip; 18. Pin; 19. Ceramic pad; 20. Sealant. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figures 1 to 4This utility model provides a technical solution: a high-precision urea pump pressure sensor, including a housing 1, a sensing connector 2, a first cantilever plate 3, a second cantilever plate 4, a first reserved hole 5, a second reserved hole 6, a wire plate 7, a wire hole 8, a lead terminal 9, a positioning buckle 10, and a top cover 11; the sensing connector 2 is provided at the lower end of the housing 1; the first cantilever plate 3 and the second cantilever plate 4 are fixed on the left and right side walls of the housing 1; the first reserved hole 5 is provided through the surface of the first cantilever plate 3; the second reserved hole 6 is provided through the surface of the second cantilever plate 4; the wire plate 7 is also provided on the side wall of the housing 1; the wire hole 8 is provided through the wire plate 7 and the housing 1; the lead terminal 9 is installed inside the wire hole 8; the positioning buckle 10 is provided on the inner side wall of the wire plate 7; the top cover 11 is provided at the upper end of the housing 1; the top cover 11 is sealed to the upper surface of the housing 1; a first sealing ring 12 is circumferentially installed on the outer side of the sensing connector 2.

[0021] A second sealing ring 13 is installed in a ring shape on the inner side of the sensor connector 2; the outer casing 1 has an upper mounting hole and a lower mounting hole, and the sensor connector 2 is inserted into the lower mounting hole, while the sensing circuit 14 is fixedly installed in the upper mounting hole.

[0022] The sensing connector 2 has a sensing groove and a sensing diaphragm 15 is installed on the sensing groove. A sensing chip 17 is installed on the upper part of the sensing diaphragm 15. A ceramic pad 19 is provided at the edge of the sensing chip 17 located above the sensing diaphragm 15. The gaps in the sensing groove of the sensing connector 2 are filled with low-temperature filling oil 16.

[0023] The sensor chip 17 has pins 18 at its terminals. Pins 18 are connected to lead terminals 9 via wires through the sensing circuit 14. The gaps in the upper and lower mounting holes inside the housing 1 are filled with sealant 20. The sensing diaphragm 15 is a corrosion-resistant stainless steel corrugated diaphragm. The housing 1 is made of nylon and glass fiber. The first sealing ring 12 and the second sealing ring 13 are both double-layer O-rings made of silicone. The filling oil 16 is diffused silicone oil-filled, and the sensor chip 17 is a diffused silicone oil-filled sensor chip.

[0024] This structure is suitable for pressure measurement in various media. During use, the pressure applied to the stainless steel diaphragm is transmitted to the sensor chip through low-temperature filling oil. It is suitable for high-precision, small-range applications. Its internal signal processing circuit uses automotive-grade components, which have good anti-electromagnetic interference capabilities. It is suitable for various complex electronic environments, extends the sensor life and improves long-term stability.

[0025] This device is a compact diffused silicon oil-filled sensor, encapsulated with a stainless steel diaphragm, a nylon and glass fiber housing, and sealed with double-layer silicone O-rings. Its diaphragm design ensures the stainless steel wetted surface is fully compatible with the corrosive chemical properties of the fluid. The internal signal processing circuitry is equipped with automotive-grade integrated circuit ASIC chips, providing excellent electromagnetic interference resistance. Suitable for various complex electronic environments, it enables output signal correction and compensation, and can store measurement data as needed, improving the stability and reliability of data measurements.

[0026] This urea pump pressure sensor is based on a piezoresistive measurement design. In practical applications, it can measure absolute fluid pressures up to 10 bar by processing diaphragm reflections. By combining a low-temperature silicone oil action structure to transfer medium pressure to the steel diaphragm, this urea pressure sensor can achieve up to 1000 freezing cycles of use. The sensor's stainless steel wetted surface is fully compatible with the corrosive chemical properties of the fluid. Despite its small and compact size, the sensor still has the ability to store data and can provide measurement accuracy with an error of no more than ±1%.

Claims

1. A high-precision urea pump pressure sensor, characterized in that: The device includes an outer casing (1), a sensor connector (2), a first cantilever plate (3), a second cantilever plate (4), a first reserved hole (5), a second reserved hole (6), a wire board (7), a wire hole (8), a lead terminal (9), a positioning buckle (10), and a top cover (11). The lower end of the outer casing (1) is provided with a sensor connector (2). The first cantilever plate (3) and the second cantilever plate (4) are fixed on the left and right side walls of the outer casing (1). The surface of the first cantilever plate (3) is provided with a first reserved hole (5). The surface of the second cantilever plate (4) is provided with a second reserved hole (6). The side wall of the outer casing (1) is also provided with a wire board (7). The wire board (7) and the outer casing (1) are connected by a wire hole (8). The wire hole (8) is installed inside the wire hole (8). The device has lead terminals (9); a positioning buckle (10) is provided on the inner side wall of the lead plate (7); a top cover (11) is provided at the upper end of the outer shell (1); the top cover (11) is sealed to the upper surface of the outer shell (1); a first sealing ring (12) is installed in a ring on the outer side of the sensor connector (2); a second sealing ring (13) is installed in a ring on the inner side of the sensor connector (2); an upper mounting hole and a lower mounting hole are reserved inside the outer shell (1), and the sensor connector (2) is inserted into the lower mounting hole, and a sensing circuit (14) is fixedly installed in the upper mounting hole; a sensing groove is processed on the sensor connector (2) and a sensing diaphragm (15) is installed on the sensing groove, and a sensing chip (17) is installed on the upper part of the sensing diaphragm (15).

2. The high-precision urea pump pressure sensor according to claim 1, characterized in that: A ceramic pad (19) is provided at the edge of the sensing chip (17) located above the sensing diaphragm (15); the gaps in the sensing groove of the sensing connector (2) are filled with low-temperature filling oil (16).

3. The high-precision urea pump pressure sensor according to claim 1, characterized in that: The sensor chip (17) has pins (18) at its terminals. The pins (18) are connected to the lead terminals (9) via wires through the sensing circuit (14).

4. The high-precision urea pump pressure sensor according to claim 1, characterized in that: The gaps in the upper and lower mounting holes inside the outer casing (1) are filled with sealant (20).

5. A high-precision urea pump pressure sensor according to claim 1, characterized in that: The sensing diaphragm (15) is made of corrosion-resistant stainless steel corrugated diaphragm.

6. A high-precision urea pump pressure sensor according to claim 2, characterized in that: The filling oil (16) is a diffused silicon oil filling, and the sensing chip (17) is a diffused silicon oil filling sensing chip.

7. A high-precision urea pump pressure sensor according to claim 1, characterized in that: The outer shell (1) is made of nylon and glass fiber.

8. A high-precision urea pump pressure sensor according to claim 1, characterized in that: Both the first sealing ring (12) and the second sealing ring (13) are made of silicone double-layer O-rings.

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