CN207472829U - For the signal stabilization device of ultrasonic wave urea concentration sensor signal measurement - Google Patents

Abstract

The utility model provides a signal stabilizing device for signal measurement of an ultrasonic urea concentration sensor. The signal stabilizing device is placed in the urea tank of the engine, and the signal stabilizing device is arranged in an integrated structure, including a top surface, a bottom surface and a side surface. The probe of the ultrasonic urea concentration sensor extends into the signal stabilizing device from the opening on the side, and the signal stabilizing device surrounds the probe of the urea concentration sensor and the measurement area, and the top and bottom surfaces are provided with nets. shape structure. The utility model protects the area of the ultrasonic urea concentration sensor signal acquisition probe to avoid the interference of the air bubbles in the urea on the urea concentration signal acquisition in actual use, so that the sensor can accurately reflect the real urea concentration signal.

Description

Signal stabilization device for signal measurement of ultrasonic urea concentration sensor

technical field

The utility model relates to the technical field of SCR processing, in particular to a signal stabilization device for signal measurement of an ultrasonic urea concentration sensor.

Background technique

With the increasingly stringent national regulations, the requirements for diesel engine emissions are getting higher and higher. In the National VI and Euro VI regulations, the requirements for _NOx emissions are becoming more and more stringent, which requires a more efficient and stable SCR post-treatment system, urea The solution is used as the reducing agent for NO _x treatment in the SCR system, and whether its concentration reaches the standard directly affects the NO _x emission of the engine.

In the prior art, ultrasonic urea concentration sensors or optical refraction urea concentration sensors are commonly used to measure urea concentration, but the cost of optical refraction urea concentration sensors is relatively high, and more manufacturers use ultrasonic urea concentration sensors. Ultrasonic urea concentration sensors are easily affected by air (bubbles) and other media. At present, there is a common problem of signal jumps. Many manufacturers use software strategies to overcome this problem.

The existing ultrasound-based urea concentration inspection method, when monitoring the urea concentration, during the operation of the engine and the whole vehicle, due to the backflow of the urea liquid return pipe into the urea tank, or the vehicle is running on bumpy road conditions, the urea tank will The urea solution produces more air bubbles. When the ultrasonic wave meets the bubbles, the urea concentration measurement signal will jump and be inaccurate, which will cause the system to report an error, cause the engine to light up the OBD light or cause the engine torque limit problem. If the software processing scheme is adopted, the ECU does not receive the signal when the urea concentration signal jumps, there is a risk of customer cheating, and the use of inferior urea when the signal jumps will not cause the on-board diagnostic system OBD to report an error, which violates the requirements of regulations.

Utility model content

The purpose of this utility model is to at least solve one of the above defects and deficiencies, and this purpose is achieved through the following technical solutions.

The utility model provides a signal stabilizing device for signal measurement of an ultrasonic urea concentration sensor. The signal stabilizing device is placed in the urea tank of the engine, and the signal stabilizing device is arranged in an integrated structure, including a top surface, a bottom surface and a side surface. The probe of the ultrasonic urea concentration sensor extends into the signal stabilizing device from the opening on the side, and the signal stabilizing device surrounds the probe of the urea concentration sensor and the measurement area, and the top and bottom surfaces are provided with nets. shape structure.

Preferably, the integral structure is a polyhedral structure.

Preferably, the side is a curved surface or a plane.

Preferably, the top surface, bottom surface and side surfaces are smooth metal surfaces.

Preferably, the integral structure is an inverted trapezoidal structure or a cuboid structure, including a top surface, a bottom surface, an opposite first side and an opposite second side, and the first side and the second side are both connected to the top surface. connected to the bottom.

Preferably, the first side is a plane, and the opening for matching with the ultrasonic urea concentration sensor probe is provided on the first side.

Preferably, the second side is a smooth curved surface.

Preferably, the mesh structure is a metal mesh.

The utility model has the following advantages:

(1) The utility model avoids the influence of air bubbles in the urea solution, and can ensure that the urea concentration sensor can accurately measure the urea concentration;

(2) The utility model is simple in structure, low in cost, and does not need complex design and transformation;

(3) The utility model has a fixed geometric structure, high reliability and no maintenance;

(4) The utility model does not need to modify the software strategy, can ensure the accuracy of the concentration measurement, and prevent customers from cheating.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating preferred embodiments, and are not considered to limit the present invention. Also throughout the drawings, the same reference numerals are used to designate the same components.

Fig. 1 is the perspective view of the urea concentration sensor signal measurement stabilizing device that the utility model embodiment provides;

Fig. 2 is the top view of the urea concentration sensor signal measurement stabilization device provided by the utility model embodiment;

Fig. 3 is the bottom view of the urea concentration sensor signal measuring and stabilizing device provided by the embodiment of the utility model;

Fig. 4 is the side view of the urea concentration sensor signal measuring and stabilizing device provided by the embodiment of the utility model;

Fig. 5 is a comparison chart of signals of urea concentration measured by an ultrasonic sensor provided by an embodiment of the present invention.

100-signal stabilization device

101-top 102-bottom

103 - first side 104 - second side

105-Metal grid

Detailed ways

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

Fig. 1 to Fig. 4 show perspective views of an ultrasonic urea concentration sensor signal measurement stabilization device provided according to an embodiment of the present invention. As shown in FIG. 1 , the signal stabilization device 100 is placed in the urea tank and is set as an inverted trapezoidal all-encompassing structure, including a top surface 101, a bottom surface 102, an opposite first side 103 and an opposite second side 104, The probe of the ultrasonic urea concentration sensor extends into the signal stabilizing device 100 from the opening on the first side 103, and the signal stabilizing device 100 surrounds and protects the probe of the urea concentration sensor and the measurement area, which can effectively protect the ultrasonic sensor probe and prevent large-diameter impurities from entering The surrounding measuring area interferes with the sensor signal measurement, keeping the urea inside the measuring area pure.

In specific implementation, the signal stabilizing device 100 can adopt other geometric structures (such as cuboid, polyhedron, etc.) to directly surround the ultrasonic urea concentration sensor, and the material and size of the geometric structure can be set as required. In a preferred implementation, each surface is a metal surface.

The top surface 101 and the bottom surface 102 are designed with metal mesh, and there is a metal mesh 105. The bottom surface 102 adopts a metal mesh structure to ensure that the urea solution can be quickly filled into the surrounding area, and the metal mesh structure on the top surface 101 can ensure that the air bubbles in the surrounding area are promptly filled. escape while avoiding the entry of external air bubbles into the surrounding area. The metal mesh design is adopted on the top surface 101 and the bottom surface 102 of the surrounding structure, which can also prevent large-diameter impurities in the urea from entering the measurement area, thereby affecting the measurement. In a specific implementation, the metal mesh structure is a porous mesh structure, and the shape of the holes can be round holes, square holes, rhombus holes, etc., and the utility model is not limited thereto.

The first side 103 connected to the top and the bottom is set as a plane, so that the probe of the urea concentration sensor can be inserted into the signal stabilization device 100 to surround the measurement area.

The second side 104 connected with the top and the bottom adopts a smooth curved surface, which can prevent air bubbles from accumulating on its surface. In a preferred implementation, the second side 104 adopts a smooth metal surface.

In a specific implementation, the upper and lower parts of the signal stabilization device 100 are surrounded by metal grids 105. When the sensor probe is placed in the urea solution, the upper and lower metal mesh surrounding structures can quickly fill the surrounding area with urea. Bubbles are generated inside, and the generated bubbles can float up to the metal mesh on the top surface 101 and escape in time, so that the bubbles are isolated from the surrounding area by the metal mesh on the top surface 101. At the same time, the inverted trapezoidal structure and smooth surface can prevent the bubbles from attaching to the surrounding area. area walls.

The utility model is verified through a bench test, and the urea concentration acquisition signal without using the device and after using the device is compared, and the standard urea concentration with a urea concentration of 32.5% is used for measurement in the test. As shown in Figure 5, in the comparison diagram of the urea concentration signal measured by the ultrasonic sensor, one curve is the urea concentration measured without the ultrasonic sensor of the utility model, and the other curve is the urea concentration measured by the ultrasonic sensor of the utility model. It can be seen from the figure that the urea concentration signal measured by the sensor without the device fluctuates greatly, and the measured signal range is 22% to 63.75%. The signal range is 32.5% to 33%, and the measurement is more accurate after using the device.

Through the test data analysis, the utility model solves the problem of abnormal signal jump caused by the ultrasonic urea concentration sensor due to air bubbles and other reasons, avoids the OBD false report of the on-board diagnostic system, has less sensor changes, low cost, and has a good application prospect .

The utility model protects the area of the signal acquisition probe of the ultrasonic urea concentration sensor to avoid the interference of the air bubbles in the urea on the acquisition of the urea concentration signal in actual use, so that the sensor can accurately reflect the real urea concentration signal, and then judge the urea concentration in the urea tank Whether it is qualified or not, the driver will be reminded through the on-board diagnostic system OBD, and the injected low-quality urea will be dealt with in time to avoid false alarms and torque limitations of the engine.

It should be pointed out that in the description of the present utility model, the terms "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations There is no such actual relationship or order between the operations.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of All changes or replacements should fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (8)

1. A signal stabilizing device for ultrasonic urea concentration sensor signal measurement, said signal stabilizing device is placed in the engine urea tank, it is characterized in that, said signal stabilizing device is set to integral structure, comprises top surface, bottom surface and side , the ultrasonic urea concentration sensor probe extends into the signal stabilizing device from the opening on the side, the signal stabilizing device surrounds the urea concentration sensor probe and the measurement area, and the top and bottom surfaces are provided with grid. 2 . The signal stabilization device according to claim 1 , wherein the integrated structure is a polyhedral structure. 3 . 3. The signal stabilization device according to claim 1, wherein the side is a curved surface or a plane. 4. The signal stabilization device according to any one of claims 1 to 3, wherein the top surface, bottom surface and side surfaces are smooth metal surfaces. 5. The signal stabilization device according to any one of claims 1 to 3, wherein the integrated structure is an inverted trapezoidal structure or a rectangular parallelepiped structure, comprising a top surface, a bottom surface, an oppositely arranged first side and an oppositely arranged The second side of the first side and the second side are both connected to the top surface and the bottom surface. 6 . The signal stabilizing device according to claim 5 , wherein the first side is a plane, and the first side is provided with the opening that cooperates with the probe of the ultrasonic urea concentration sensor. 7 . 7. The signal stabilization device according to claim 5, wherein the second side is a smooth curved surface. 8. The signal stabilization device according to any one of claims 1 to 3, characterized in that, the mesh structure is a metal mesh.