CN218844416U - Urea quality sensor with scouring structure - Google Patents

Abstract

The utility model provides a urea quality sensor of structure is washed in area, including urea cavity, ultrasonic transducer and sensor circuit, the sensor circuit with ultrasonic transducer connects, the urea cavity includes the ultrasonic reflection board, the urea cavity with interior wall mounting ultrasonic transducer that the ultrasonic reflection board is relative is still including setting up the sensor washing device of ultrasonic transducer top, the jet direction of sensor washing device is towards ultrasonic transducer. The utility model discloses a urea pump returns liquid and is connected to ultrasonic sensor top through the honeycomb duct, does sensor washing device, continuously erodees the ultrasonic sensor surface, takes away sensor surface adnexed bubble, avoids the bubble to urea concentration measurement's influence, and urea detects more most accurately.

Description

Urea quality sensor with scouring structure

Technical Field

The utility model belongs to the technical field of the engine aftertreatment, specifically a urea quality sensor of structure is erodeed in area.

Background

The main purification part of NOx in the tail gas of the diesel engine is an SCR (selective catalytic reduction) catalyst, a mixer is arranged in front of the SCR catalyst, and a urea nozzle is arranged on the mixer. The urea injection system calculates the required urea consumption according to the information of the temperature condition of the SCR catalyst, the working condition of the diesel engine and the like, the vehicle urea solution is injected into the mixer through the nozzle, the urea solution is decomposed into NH3 at high temperature and is fully mixed with the high-temperature tail gas of the diesel engine, the mixture enters the SCR catalyst and reacts with NOx in the catalyst to generate N2 and H20, and the purification of the NOx is realized.

The urea concentration is required to be monitored in real time by national six-emission regulations of diesel engines, and the detection of the urea concentration by ultrasonic waves is a common method. The ultrasonic wave is similar to the effect of a transducer, transmits sound waves with certain frequency through electric signal conversion, receives echoes rebounded when encountering obstacles, depends on the physical phenomenon that the transmission speed of the ultrasonic wave in liquid with different concentrations is different, and measures the concentration of urea through echo time.

When urea is filled into an empty tank or a vehicle passes through a bumpy road, the urea solution shakes and impacts the wall of the tank, a large amount of bubbles can be generated in the urea solution and can be attached to the surface of the ultrasonic sensor, the speed of sound waves in the air is low, the concentration value of the urea measured under the condition of bubbles is low, the engine can mistakenly report the low-concentration urea fault, and the engine can limit the speed if the fault cannot be eliminated for a long time.

Also like the ultrasonic probe for urea sensor disclosed in chinese patent CN113820388a, including the casing, its characterized in that: the utility model discloses a novel urea solution probe, including casing, filter screen, probe rubber pad, O type sealing washer, probe main part internally mounted has probe metal casing, probe main part one side internally mounted has NTC resistance, first O type sealing washer is cup jointed to probe metal casing surface, the inside probe rubber pad that is equipped with of probe metal casing, probe rubber pad one end is equipped with the ground connection wire jumper, probe PCB board is installed to probe rubber pad one side, and the effectual bubble that blocks in the urea solution of filter screen gets into inside the probe. This scheme is through inside the effectual bubble immersion probe that blocks in the urea solution of the inside filter screen of casing, prevents that the bubble from attaching to ultrasonic transducer's transmitting surface and plane of reflection to eliminated the influence of bubble to ultrasonic detection, and prevented gas overstock in inside through giving vent to anger the mouth. The scheme has a complex structure and low sealing reliability, is completely sealed by the sealing ring and the rubber pad, and can directly cause the functional failure of the probe once the sealing failure is caused by the loosening of the thread.

SUMMERY OF THE UTILITY MODEL

The utility model provides a urea quality sensor of structure is erodeed in area, urea pump return liquid pass through fluid guide connection to ultrasonic sensor top, do sensor washing device, continuously erode the ultrasonic sensor surface, take away sensor surface adnexed bubble, avoid the bubble to urea concentration measurement's influence, urea detects more accurately.

The technical scheme of the utility model as follows: the utility model provides a urea quality sensor of structure is erodeed in area, includes urea cavity, ultrasonic transducer and sensor line, the sensor line with ultrasonic transducer connects, the urea cavity includes the ultrasonic reflection board, the urea cavity with the relative interior wall mounting ultrasonic transducer of ultrasonic reflection board is still including setting up the sensor washing device of ultrasonic transducer top, the sensor washes the jet direction orientation ultrasonic transducer of device.

The utility model discloses in, sensor washing away device and honeycomb duct intercommunication, the sensor washing away device of liquid through honeycomb duct connection to ultrasonic sensor top of returning of urea pump, continuously erode the ultrasonic sensor surface, take away sensor surface adnexed bubble.

Preferably, the jet direction of the sensor flushing device is towards the cross section of the ultrasonic probe. The cross section is the area that the bubble is concentrated, is favorable to improving the efficiency of washing away of bubble, avoids the influence of bubble to urea concentration measurement.

Preferably, the ultrasonic probe mounting wall surface is configured as a plane parallel to the ultrasonic reflection plate. Simple structure, ultrasonic sensor can be better return detected signal, and the testing result is accurate.

Preferably, the urea cavity is of a cuboid structure. Simple structure and low cost.

Preferably, the ultrasonic probe is connected to the inner wall of the urea cavity through two hexagon socket head cap screws, the cross section of the ultrasonic probe protrudes out of the installation wall surface by 2-4 mm, so that bubble aggregation can be reduced as little as possible, and the influence of bubbles on urea concentration measurement is reduced and avoided.

The utility model has the advantages that:

the urea pump return liquid is connected above the ultrasonic sensor, and the urea pump return liquid is used for flushing the ultrasonic sensor, so that bubbles attached to the sensor are flushed away, and the influence of the bubbles on the urea concentration measurement is avoided.

Compare with current structure, the structure is simpler, with sensor washing device and honeycomb duct intercommunication, and the sensor washing device of liquid through honeycomb duct connection to ultrasonic sensor top is passed through to the liquid that returns of urea pump, and is with low costs.

Drawings

Fig. 1 is a schematic structural diagram of a urea quality sensor with a flushing structure according to the present invention.

Fig. 2 is a working principle diagram of a urea quality sensor with a flushing structure according to the present invention.

In the figure: the device comprises a urea cavity, a 101-ultrasonic reflection plate, a 2-ultrasonic probe, a sensor line 3-, a 4-sensor flushing device, a 5-inner hexagon bolt and a 6-flow guide pipe.

Detailed Description

The invention will be further described with reference to the accompanying drawings and specific embodiments, which are illustrative of the invention and are not to be construed as unduly limiting the invention.

Example 1:

as shown in fig. 1, a urea quality sensor of structure is washd in area detects the urea quality, including urea cavity 1, ultrasonic transducer 2 and sensor circuit 3, sensor circuit 3 with ultrasonic transducer 2 connects, urea cavity 1 includes ultrasonic reflection board 101, urea cavity 1 with ultrasonic reflection board 101 relative inner wall installation ultrasonic transducer 2, still including setting up the sensor washing device 4 of ultrasonic transducer 2 top, sensor washing device 4's injection direction is towards ultrasonic transducer 2.

As shown in fig. 2, the working principle of the present embodiment is: the sensor scouring device 4 is communicated with the flow guide pipe 6, liquid returning through the urea pump is connected to the sensor scouring device 4 above the ultrasonic sensor through the flow guide pipe 6, the surface of the ultrasonic probe 2 is continuously scoured, and bubbles attached to the surface of the ultrasonic probe 2 are taken away.

The influence of a large amount of bubbles generated in the urea solution on the detection of the concentration value of the urea is avoided when the urea is filled into an empty tank or a vehicle passes through a bumpy road and the urea solution shakes and impacts the tank wall.

Example 2:

as shown in figure 1, a urea quality sensor of structure is washed in area, including urea cavity 1, ultrasonic probe 2 and sensor circuit 3, sensor circuit 3 with ultrasonic probe 2 connects, urea cavity 1 includes ultrasonic reflection board 101, urea cavity 1 with ultrasonic reflection board 101 relative interior wall mounting ultrasonic probe 2, still including setting up the sensor washing device 4 of ultrasonic probe 2 top, the injection direction of sensor washing device 4 is towards ultrasonic probe 2.

As shown in fig. 2, in this embodiment, the sensor flushing device 4 is communicated with the flow guide pipe 6, the return liquid passing through the urea pump is connected to the sensor flushing device 4 above the ultrasonic sensor through the flow guide pipe 6, the surface of the ultrasonic probe 2 is continuously flushed, and bubbles attached to the surface of the sensor are taken away.

As shown in fig. 2, the jetting direction of the sensor flushing device 4 is preferably towards the cross section of the ultrasonic probe 2;

the ultrasonic probe 2 mounting wall surface is configured as a plane parallel to the ultrasonic reflection plate 101;

the urea cavity 1 is of a cuboid structure;

the ultrasonic probe 2 is connected to the inner wall of the urea cavity 1 through two hexagon socket head cap bolts 5, and the cross section of the ultrasonic probe 2 protrudes out of the installation wall surface by 2-4 mm.

Claims (5)

1. The utility model provides a urea quality sensor of structure is erodeed in area, includes urea cavity (1), ultrasonic transducer (2) and sensor line (3), sensor line (3) with ultrasonic transducer (2) are connected, its characterized in that: urea cavity (1) includes ultrasonic reflection board (101), urea cavity (1) with interior wall mounting ultrasonic probe (2) that ultrasonic reflection board (101) are relative are still including setting up sensor washing device (4) of ultrasonic probe (2) top, the injection direction of sensor washing device (4) is towards ultrasonic probe (2).

2. The urea quality sensor with a flushing structure according to claim 1, wherein: the spraying direction of the sensor flushing device (4) faces the cross section of the ultrasonic probe (2).

3. The urea quality sensor with a flushing structure according to claim 2, characterized in that: the ultrasonic probe (2) mounting wall surface is configured as a plane parallel to the ultrasonic reflection plate (101).

4. The urea quality sensor with a flushing structure of claim 2, wherein: the urea cavity (1) is of a cuboid structure.

5. The urea quality sensor with a flushing structure of claim 2, wherein: the ultrasonic probe (2) is connected to the inner wall of the urea cavity (1) through two hexagon socket head cap screws (5).

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