Adblue quality sensor probe

Abstract

The utility model discloses an automotive urea quality sensor probe which comprises a probe base, a gas pipe joint and an ultrasonic transducer, and the ultrasonic transducer is installed on the probe base. At least one end of the probe base is open, and an ultrasonic signal receiving and transmitting end of the ultrasonic transducer faces the open end of the probe base; the probe base is provided with an airflow channel, an airflow inlet and an airflow outlet, and the airflow inlet and the airflow outlet are respectively communicated with the airflow channel; the air pipe joint is mounted at an airflow inlet of the probe base; the airflow outlet is arranged corresponding to the ultrasonic signal receiving and transmitting end of the ultrasonic transducer and used for blowing away bubbles attached to the end face of the ultrasonic signal receiving and transmitting end of the ultrasonic transducer. According to the ultrasonic transducer, bubbles attached to the end face of the ultrasonic signal receiving and transmitting end of the ultrasonic transducer can be scoured through an external air source, bubbles of various sizes can be effectively scoured and eliminated, and the working condition of the ultrasonic transducer is improved.

Description

Technical Field

[0001] This utility model belongs to the field of sensors, and more specifically, relates to a urea quality sensor probe for vehicles. Background Technology

[0002] Motor vehicle emissions are a significant source of air pollution, and approximately 75% of nitrogen oxides (NOx) in air pollutants are caused by heavy-duty diesel vehicles. With the implementation of the China VI emission standard, the emission limits for nitrogen oxides (NOx) are becoming increasingly stringent.

[0003] To reduce air pollution from heavy-duty diesel vehicles, most heavy-duty diesel vehicles now use SCR after-treatment systems, which convert nitrogen oxides (NOx) into nitrogen and water by injecting automotive urea solution into the exhaust pipe, thereby reducing air pollution.

[0004] To accurately control the injection volume of automotive urea solution, a urea quality sensor in the urea storage tank is needed to provide accurate concentration information. Currently, the mainstream concentration detection technology is ultrasonic technology. By measuring the time of flight (TOF) of ultrasound waves over a fixed distance, the propagation speed of ultrasound waves in the automotive urea solution is obtained, and temperature compensation is combined to invert the concentration of the automotive urea solution.

[0005] Urea quality sensors typically consist of an ultrasonic transducer, a reflector, and corresponding connecting and supporting devices. When diesel engine vehicles are subjected to various operating conditions such as temperature changes, altitude changes, acceleration / deceleration, and hill climbing, as well as when new vehicles are refilled with automotive urea solution or when urea solution is replenished during operation, a large number of small and microbubbles of different sizes are generated. These microbubbles, in particular, can remain for several minutes or even tens of minutes.

[0006] Currently, the ultrasonic ceramic transducers used in urea quality sensors operate primarily between 1MHz and 2MHz. When the gaseous concentration of the automotive urea solution in the urea storage tank is 50%, the attenuation coefficient of the ultrasonic waves reaches its maximum. This problem can be solved by increasing the transmission power of the ultrasonic ceramic transducer. However, due to the surface finish and material properties of the ultrasonic transducer's transducer end face (the end used to transmit / receive signals, through which ultrasonic signals enter and exit), bubbles adsorbed at the transducer end face form a gas phase barrier layer, which is difficult to eliminate naturally. The gas in the bubbles adsorbed at the transducer end face has similar components and properties to air. The acoustic impedance of the gas phase barrier layer in the 1MHz-2MHz frequency band is approximately 415 Rayles (Rayl), while the acoustic impedance of a typical 32.5% automotive urea solution in the same frequency band is 1.67 MegaRayl (MRayl), a significant difference. Significant differences in acoustic impedance cause strong reflections of ultrasonic waves at the gas-liquid interface, preventing the ultrasonic probe's signal from reaching the reflector and forming an effective echo. Furthermore, the transceiver ends of ultrasonic signals are typically made of stainless steel or engineering plastic, which, due to manufacturing processes, have a certain surface roughness. Small, micro-bubbles can adhere to the ultrasonic transducer and reflector, significantly weakening or even eliminating the ultrasonic echo signal. This can cause the urea quality sensor ECU (electronic control unit) to misdiagnose faults such as short circuits or open circuits in the ultrasonic transducer, issuing an FMI (Fault Mode Identification Code) signal. This prevents the urea quality sensor from accurately measuring the concentration of automotive urea solution, leading to errors in vehicle signals and potentially triggering "torque reduction and speed limiting" functions, putting the vehicle into "limp mode" and severely impacting normal vehicle operation.

[0007] To prevent air bubbles, especially microbubbles, from affecting the operation of ultrasonic transducers, certain measures are needed to eliminate the air bubbles adsorbed on the end face of the ultrasonic transducer's transceiver. One measure is to add a rubber protective sleeve, but the large gaps in the sleeve still cannot prevent air bubbles from entering the vicinity of the ultrasonic transducer and adsorbing on the end face of the transceiver. Another measure is to apply a hydrophilic treatment to the end face of the transceiver to reduce air bubble adsorption, but this hydrophilic treatment is not permanent and will lose its hydrophilicity during use. With both of these measures, air bubbles will remain on the end face of the ultrasonic transducer's transceiver after a period of use, and these air bubbles cannot be eliminated, affecting the accuracy of the ultrasonic transducer's detection. Utility Model Content

[0008] To address the aforementioned deficiencies or improvement needs of existing technologies, this utility model provides a vehicle urea quality sensor probe. The probe base has an airflow channel, allowing airflow to be introduced into the channel via an external air source. This airflow can flush away and eliminate air bubbles adhering to the end face of the ultrasonic transducer's ultrasonic signal transceiver, thus solving the problem of a large number of air bubbles adhering to the end face of the ultrasonic transducer and causing the ultrasonic transducer's echo signal to disappear when diesel engine vehicles are refueled after new production, during operation, or when changes in the driving environment occur.

[0009] To achieve the above objectives, according to this utility model, a vehicle urea quality sensor probe is provided, characterized in that it includes a probe base, a tracheal connector, and an ultrasonic transducer, wherein:

[0010] The ultrasonic transducer is mounted on the probe base;

[0011] The probe base is open at at least one end, and the ultrasonic signal transceiver of the ultrasonic transducer faces the open end of the probe base so that the ultrasonic signal transceiver of the ultrasonic transducer is immersed in automotive urea solution.

[0012] The probe base is provided with an airflow channel, an airflow inlet and an airflow outlet, and the airflow inlet and airflow outlet are respectively connected to the airflow channel;

[0013] The tracheal connector is installed at the airflow inlet of the probe base for connecting to an external air source;

[0014] The airflow outlet is arranged corresponding to the ultrasonic signal transceiver of the ultrasonic transducer to blow away air bubbles attached to the end face of the ultrasonic signal transceiver of the ultrasonic transducer.

[0015] Preferably, the probe base includes an outer cylinder, an inner cylinder, and two sealing structures. There is a gap between the inner wall of the outer cylinder and the outer wall of the inner cylinder. The two sealing structures are arranged along the axial direction of the outer cylinder. Each sealing structure is sealed to the inner wall of the outer cylinder and the outer wall of the inner cylinder, respectively. The space enclosed by the outer cylinder, the inner cylinder, and the two sealing structures forms the airflow channel. The airflow inlet and the airflow outlet are respectively arranged on the outer cylinder and the inner cylinder.

[0016] The ultrasonic transceiver of the ultrasonic transducer extends into the inner cavity of the inner cylinder and is fixedly installed on the inner cylinder.

[0017] Preferably, the outer cylinder, the inner cylinder, and one of the sealing structures are integrally formed, and the other sealing structure is a cover plate that covers one end of the inner cylinder. The inner cylinder and the outer cylinder are respectively welded to the cover plate, and the airflow outlet is provided at the end of the inner cylinder near the cover plate.

[0018] Preferably, the airflow outlet is a notch or groove on the end face of the inner cylinder, the cover plate covers the notch or groove, and the end face of the ultrasonic signal transceiver of the ultrasonic transducer is flush with the bottom of the notch or groove.

[0019] Preferably, the notch has a width of 2mm-5mm and a depth of 0.3mm-0.6mm.

[0020] Preferably, both the inner and outer cylinders are open at both ends, the ultrasonic signal transceiver of the ultrasonic transducer faces the first end of the outer cylinder, and the second end of the outer cylinder is provided with potting compound to seal the ultrasonic transducer.

[0021] Preferably, the ultrasonic transducer is provided with a limiting flange, which is located outside the inner cylinder and abuts against the end of the inner cylinder to limit the axial displacement of the ultrasonic transducer.

[0022] Preferably, the ultrasonic transducer is equipped with a temperature sensor to obtain the temperature of the automotive urea solution.

[0023] Preferably, a lead wire conduit is installed on the probe base, and the signal wires of the ultrasonic transducer and the temperature sensor are respectively led out from the lead wire conduit.

[0024] Preferably, there are multiple airflow outlets arranged in a circumferentially uniform manner.

[0025] In summary, compared with the prior art, the above-described technical solution conceived by this utility model can achieve the following beneficial effects:

[0026] 1) The present invention relates to a vehicle urea quality sensor probe, wherein an airflow channel is provided on the probe base, the air source connector at the airflow inlet can be connected to an external air source, and the airflow coming out at the airflow outlet can flush away the air bubbles attached to the end face of the ultrasonic signal transceiver of the ultrasonic transducer, effectively flushing and eliminating air bubbles of various sizes adsorbed on the end face of the ultrasonic signal transceiver of the ultrasonic transducer, improving the working conditions of the ultrasonic transducer, greatly reducing the influence of air bubbles attached to the end face on the ultrasonic transducer's transmitted signal and echo signal, significantly improving the detection accuracy and precision of the ultrasonic transducer, and the probe base is easy to manufacture and install at low cost, which can effectively reduce the cost of the entire vehicle urea quality sensor probe.

[0027] 2) The present invention provides a vehicle urea quality sensor probe. The probe base has an outer cylinder, an inner cylinder and two sealing structures, which form an airflow channel to facilitate the installation of an ultrasonic transducer and to facilitate the blowing of gas to the ultrasonic signal transceiver of the ultrasonic transducer. Attached Figure Description

[0028] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0029] Figure 2 This is a schematic diagram of the present invention after a portion has been removed. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0031] Reference Figure 1 , Figure 2 A vehicle urea quality sensor probe includes a probe base 1, a tracheal connector 2, and an ultrasonic transducer 3, wherein:

[0032] The ultrasonic transducer 3 is mounted on the probe base 1;

[0033] The probe base 1 has at least one open end, and the ultrasonic transceiver of the ultrasonic transducer 3 faces the open end of the probe base 1, allowing the ultrasonic transceiver of the ultrasonic transducer 3 to be immersed in the automotive urea solution. If the probe base 1 has two open ends, the ultrasonic transceiver of the ultrasonic transducer 3 faces either open end of the probe base 1. The ultrasonic transceiver of the ultrasonic transducer 3 can emit ultrasonic waves into the automotive urea solution for detection; the open end of the probe base 1 will cause air bubbles in the automotive urea solution to adhere to the ultrasonic transceiver of the ultrasonic transducer 3, therefore, the air bubbles need to be flushed and defoamed. The ultrasonic transceiver can both emit and receive ultrasonic signals, serving as the end of the ultrasonic transducer 3 that emits and / or receives signals. The ultrasonic signal enters / exits the ultrasonic transducer from the end face of the ultrasonic transceiver. Preferably, the ultrasonic transducer of this invention is a transceiver integrated transducer.

[0034] The probe base 1 is provided with an airflow channel 101. The airflow channel 101 can be any type of channel, as long as it allows airflow to flow within the probe base 1.

[0035] The probe base 1 is also provided with an airflow inlet 102 and an airflow outlet 103, which are used for air intake and air exhaust, respectively. The airflow inlet 102 and the airflow outlet 103 are respectively connected to the airflow channel 101.

[0036] The tracheal connector 2 is installed at the airflow inlet 102 of the probe base for connecting to an external air source. The tracheal connector 2 connects to the air source via a tracheal tube. The external air source can be an electric air pump, whose start and stop timing is controlled by an electronic control unit (ECU). The electric air pump has a flow rate of 0.15L / min-0.5L / min and a pressure of 0.03Mpa-0.1Mpa.

[0037] The airflow outlet 103 is arranged corresponding to the ultrasonic signal transceiver end of the ultrasonic transducer 3 to blow away air bubbles attached to the end face 31 of the ultrasonic signal transceiver end of the ultrasonic transducer 3. After the air bubbles on the end face of the ultrasonic signal transceiver end are blown away, they will not re-adsorb air bubbles within a short period of time, thus the ultrasonic detection process can be free from interference from air bubbles on the end face, improving the accuracy and precision of ultrasonic detection. Preferably, multiple airflow outlets 103 are arranged, and these airflow outlets 103 are evenly distributed circumferentially, which can blow away air bubbles attached to the end face 31 of the ultrasonic signal transceiver end of the ultrasonic transducer 3 from multiple directions. If air bubbles re-adhere to the end face after a period of time, they can be blown away again.

[0038] Furthermore, the probe base 1 includes an outer cylinder 11, an inner cylinder 12, and two sealing structures. There is a gap between the inner wall of the outer cylinder 11 and the outer wall of the inner cylinder 12. The two sealing structures are arranged along the axial direction of the outer cylinder 11, and each sealing structure is respectively sealed to the inner wall of the outer cylinder 11 and the outer wall of the inner cylinder 12. The annular space enclosed by the outer cylinder 11, the inner cylinder 12, and the two sealing structures forms the airflow channel 101. This annular space makes the airflow relatively smooth and will not disturb the urea solution, thus preventing the internal flow field of the urea solution from becoming turbulent. The airflow inlet 102 and the airflow outlet 103 are respectively arranged on the outer cylinder 11 and the inner cylinder 12. The inner cylinder 12 is designed to facilitate the installation of an ultrasonic transducer. The distance between the outer cylinder 11 and the inner cylinder 12 facilitates the formation of the airflow channel 101. The two sealing structures can seal the space between the outer cylinder 11 and the inner cylinder 12, thereby forming a sealed airflow channel 101 to allow gas to flow.

[0039] The ultrasonic transducer 3 has its ultrasonic signal transceiver end extending into the inner cavity of the inner cylinder 12 and fixedly mounted on the inner cylinder 12. A limiting flange 32 is provided on the ultrasonic transducer 3, located outside the inner cylinder 12 and abutting against the end of the inner cylinder 12 to limit the axial displacement of the ultrasonic transducer 3. The probe base 1 has at least one open end, so that both the outer cylinder 11 and the inner cylinder 12 have an open end. Automotive urea solution can contact the ultrasonic signal transceiver end of the ultrasonic transducer 3 from the open end of the probe base 1. Ultrasonic waves are emitted from the open ends of the inner cylinder 12 and the outer cylinder 11, while the airflow from the air outlet 103 blows away air bubbles attached to the end face 31 of the ultrasonic signal transceiver end of the ultrasonic transducer 3. The inner cylinder 12 and the outer cylinder 11 are preferably both open at both ends. The ultrasonic signal transceiver end of the ultrasonic transducer 3 faces the first end of the outer cylinder 11, and the second end of the outer cylinder 11 is provided with potting compound to seal the ultrasonic transducer 3.

[0040] Furthermore, the outer cylinder 11, inner cylinder 12, and one of the sealing structures are integrally formed. This integrally formed sealing structure is an annular platform 13, and the other sealing structure is a cover plate 14 that covers one end of the inner cylinder 12. The inner cylinder 12 and the outer cylinder 11 are respectively welded to the cover plate 14 to form a seal. The airflow outlet 103 is provided at the end of the inner cylinder 12 near the cover plate 14. In addition, the airflow outlet 103 is a notch groove on the end face of the inner cylinder 12. The cover plate 14 covers the notch groove, and the end face of the ultrasonic signal transceiver of the ultrasonic transducer 3 is flush with the bottom of the notch groove. The limiting flange 32 ensures that after the ultrasonic transducer 3 is installed, the end face of the ultrasonic signal transceiver of the ultrasonic transducer 3 is exactly located at the bottom of the notch groove. After the notch groove is formed, the cover plate 14 is placed on the inner cylinder 12 and then welded. The notch groove has a width of 2mm-5mm and a depth of 0.3mm-0.6mm. The ultrasonic transducer 3 of the automotive urea quality sensor probe has a relatively uniform size, and this size range of the notch can accommodate the elimination of air bubbles in most ultrasonic transducers. The number of airflow outlets 103 is preferably 1-6 (but not limited to 6). When there is only one outlet, it is located at opposite ends of the air pipe connector 2, with the flushing direction vertically upward along the horizontal plane. When there are 2-6 outlets, they are evenly arranged.

[0041] Furthermore, a temperature sensor is installed on the ultrasonic transducer 3 to obtain the temperature of the automotive urea solution. Additionally, a lead conduit 4 is installed on the probe base 1, from which the signal lines of the ultrasonic transducer 3 and the temperature sensor are respectively led out.

[0042] The automotive urea quality sensor probe of this invention is connected to external components such as a probe reflector, an electronic control board (ECU), and an electric air pump, which together constitute the automotive urea quality sensor. In the automotive urea quality sensor probe of this invention, the ultrasonic transducer 3 houses a piezoelectric ceramic plate and a temperature sensor. The signal lines from the piezoelectric ceramic plate and the temperature sensor are led to the ECU via a lead conduit 4.

[0043] This invention uses an electronic control unit (ECU) to control the bubble flushing operation of the automotive urea quality sensor. The flushing can be performed at regular intervals or the flushing timing can be set according to the flushing control strategy.

[0044] This invention preferably controls the flushing of air bubbles based on the detection signal received by the electronic control unit (ECU). After the ECU is powered on and operating normally, it sets the detection threshold for the ultrasonic echo signal by checking the amplitude of the echo signal. When a large number of air bubbles are present in the urea storage tank under various specific operating conditions, the ECU will set the detection threshold to its maximum. If no echo signal is detected, combined with the liquid level and temperature signal from the ultrasonic transducer 3, it can be determined that the automotive urea solution in the urea storage tank is in a gas-liquid two-phase mixed state. Specifically, the liquid level is used to determine whether the probe is in air or automotive urea solution. Sensor probes designed for liquid environments do not have a signal in air. The temperature detected by the temperature sensor is used to determine whether the temperature exceeds the operating range of the ultrasonic transducer 3. If it does, there is no echo signal. If the sensor probe is in liquid and the temperature is within the operating range, but the signal is lost, except for the exception of damage to the ultrasonic transducer 3, it can be determined that the automotive urea solution is in a gas-liquid two-phase mixed state.

[0045] In a gas-liquid two-phase mixture, small and microbubbles in the liquid rise and coalesce, causing the gas phase component to gradually decrease over time. When the electronic control unit (ECU) determines that the automotive urea solution in the urea storage tank is in a gas-liquid two-phase state, the ECU controls the electric air pump to start, allowing gas to flow through the gas outlet 103 to flush the end face 31 of the ultrasonic transducer 3, removing bubbles adhering to the end face 31 of the ultrasonic transducer 3. After the electric air pump starts flushing for a period of time, it stops working, ending the flushing and defoaming process. The ECU then readjusts the detection threshold to detect the echo signal. If no valid echo signal is detected, the electric air pump is restarted for flushing. If no echo signal is detected after exceeding the set number of flushing cycles, an error alarm signal is issued, indicating a sensor malfunction. The probe base 1 of this invention is tightly integrated with the ultrasonic transducer 3, resulting in a compact structure that facilitates integration with existing urea storage tanks. The airflow flushing process is automatically controlled by the electronic control board and is only activated when air bubbles are present in the urea storage tank under various special operating conditions. The flushing time is short and does not affect the gaseous or liquid phases in the urea storage tank. This invention provides excellent flushing performance, effectively removing air bubbles of various sizes adsorbed on the end face 31 of the ultrasonic transducer 3, improving the working conditions of the ultrasonic transducer 3, and ensuring that the transmitted and echo signals are not affected by air bubbles adsorbed on the end face 31 of the ultrasonic transducer 3. When air bubbles are detected affecting normal ultrasonic measurement, defoaming can restore the ultrasonic transducer 3 to normal measurement within 60-90 seconds.

[0046] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A urea quality sensor probe for vehicles, characterized by, Includes probe base, endotracheal connector, and ultrasonic transducer, wherein: The ultrasonic transducer is mounted on the probe base; The probe base is open at at least one end, and the ultrasonic signal transceiver of the ultrasonic transducer faces the open end of the probe base so that the ultrasonic signal transceiver of the ultrasonic transducer is immersed in automotive urea solution. The probe base is provided with an airflow channel, an airflow inlet and an airflow outlet, and the airflow inlet and airflow outlet are respectively connected to the airflow channel; The tracheal connector is installed at the airflow inlet of the probe base for connecting to an external air source; The airflow outlet is arranged corresponding to the ultrasonic signal transceiver of the ultrasonic transducer to blow away air bubbles attached to the end face of the ultrasonic signal transceiver of the ultrasonic transducer.

2. The urea quality sensor probe for vehicles according to claim 1, characterized by The probe base includes an outer cylinder, an inner cylinder, and two sealing structures. There is a gap between the inner wall of the outer cylinder and the outer wall of the inner cylinder. The two sealing structures are arranged along the axial direction of the outer cylinder. Each sealing structure is sealed to the inner wall of the outer cylinder and the outer wall of the inner cylinder, respectively. The space enclosed by the outer cylinder, the inner cylinder, and the two sealing structures forms the airflow channel. The airflow inlet and the airflow outlet are respectively arranged on the outer cylinder and the inner cylinder. The ultrasonic transceiver of the ultrasonic transducer extends into the inner cavity of the inner cylinder and is fixedly installed on the inner cylinder.

3. The urea quality sensor probe for vehicles according to claim 2, characterized by The outer cylinder, the inner cylinder, and one of the sealing structures are integrally formed. The other sealing structure is a cover plate that covers one end of the inner cylinder. The inner cylinder and the outer cylinder are respectively welded to the cover plate. The airflow outlet is provided at the end of the inner cylinder near the cover plate.

4. The urea quality sensor probe for vehicles according to claim 3, characterized by The airflow outlet is a notch or groove on the end face of the inner cylinder. The cover plate covers the notch or groove, and the end face of the ultrasonic signal transceiver of the ultrasonic transducer is flush with the bottom of the notch or groove.

5. The urea quality sensor probe for vehicles according to claim 4, characterized by The notch has a width of 2mm-5mm and a depth of 0.3mm-0.6mm.

6. The urea quality sensor probe for vehicles according to claim 2, characterized by Both the inner and outer cylinders are open at both ends. The ultrasonic signal transceiver of the ultrasonic transducer faces the first end of the outer cylinder, and the second end of the outer cylinder is provided with potting compound to seal the ultrasonic transducer.

7. The urea quality sensor probe for vehicles according to claim 2, characterized by The ultrasonic transducer is provided with a limiting flange, which is located outside the inner cylinder and abuts against the end of the inner cylinder to limit the axial displacement of the ultrasonic transducer.

8. The urea quality sensor probe for vehicles according to claim 1, characterized by The ultrasonic transducer is equipped with a temperature sensor to obtain the temperature of the automotive urea solution.

9. The urea quality sensor probe for vehicles according to claim 8, characterized by A lead wire conduit is installed on the probe base, and the signal lines of the ultrasonic transducer and the temperature sensor are respectively led out from the lead wire conduit.

10. A vehicle urea quality sensor probe according to claim 1, characterized in that, The airflow outlets are arranged in multiple ways and are evenly distributed circumferentially.

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