Urea ultrasonic sensor bubble removing device and urea box

Abstract

The utility model discloses a urea ultrasonic sensor bubble removing device and a urea box, the bubble removing device comprises a shunting device arranged on an overflow pipe communicated with a urea pump, and the shunting device is provided with a urea outlet leading to a sensor and a urea outlet flowing back into the urea box; liquid overflowing from the urea pump is shunted through the two urea outlets, so that part of urea water solution directly flows back into the urea box, and part of the urea water solution is led to the emitting surface and the reflecting surface of the ultrasonic sensor so as to remove bubbles possibly generated on the surface of the ultrasonic sensor. The flow dividing device is used for dividing the overflow into two parts, the flow led to the urea sensor is adjusted, the scouring strength is controlled, the overflow back pressure is reduced, and the negative influence caused by an overflow pipe is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of diesel engine post-processing, and more specifically, to a urea ultrasonic sensor degassing device and a urea tank. Background Art

[0002] Urea sensors in current diesel engine aftertreatment systems generally use ultrasound to detect the concentration (quality) of urea aqueous solution (hereinafter referred to as urea), and are equipped with a float sensor to detect the liquid level, or are also equipped with an ultrasonic sensor to detect the liquid level.

[0003] Figure 1 A typical arrangement of an overhead urea pump is shown: a urea pump 100 is installed on the top of a urea tank 200 through a connecting chuck 110; there is urea (aqueous solution) 220 in the urea tank; the urea pump 100 extracts urea 220 from the bottom of the urea tank 200 through a liquid inlet pipe 120, and then supplies urea to a nozzle (not shown) through a urea injection pipe 130; in fact, the urea supplied to the nozzle (not shown) by the urea pump 100 is only a small part of the urea extracted from the urea tank 200 by the urea pump, and most of the urea flows back into the urea tank through an overflow valve 140; in order to detect the liquid level and urea quality (the concentration of urea in the urea aqueous solution) of the urea tank, a urea sensor 300 is arranged at the bottom of the urea tank; the sensor is composed of two ultrasonic sensors (one for detecting urea concentration and the other for detecting urea liquid level) or one ultrasonic sensor (only detecting urea concentration); as shown in FIG. Figure 3 As shown, the quality (concentration) sensor ultrasonic transmitting surface 310 and the quality (concentration) sensor ultrasonic reflecting surface 320 of the sensor 300, as well as the liquid level sensor ultrasonic transmitting surface 330 (if any) are in contact with urea; in actual applications, bubbles often adhere to these ultrasonic transmitting surfaces and reflecting surfaces, affecting the transmission and reception of ultrasonic signals.

[0004] There is a technology that leads the overflow of the urea pump 100 to the vicinity of the above-mentioned urea sensor to flush the ultrasonic emission and reflection surfaces and remove the bubbles attached thereto. Figures 2-3 As shown, the overflow valve 140 guides part of the overflowed urea to the vicinity of the ultrasonic urea sensor 300 (installed at the bottom of the urea tank) through the overflow pipe 150. This technology has the following fatal defects in actual application:

[0005] 1) Since the final overflow outlet is moved from the top of the urea tank to the bottom of the urea tank, the overflow outlet pressure increases with the increase of urea liquid level. In particular, the back pressure is large when the urea pump is emptied, which affects the emptying of the urea pump and even causes pressure building failure in severe cases;

[0006] 2) When the vehicle is idle for a long time, if there is residual urea in the overflow pipe 150, it may crystallize due to dehydration, causing the overflow channel to be blocked, affecting the normal operation of the urea pump, especially the failure of emptying and pressure building;

[0007] 3) In cold weather, the residual urea in the overflow pipe 150 freezes. If there is no appropriate method to heat and thaw it, it will also cause the overflow channel to be blocked, affecting the normal operation of the urea pump, especially the failure of emptying and pressure building;

[0008] 4) Flushing the surface of the urea sensor at high intensity (high speed) may cause damage to the sensor surface coating; at the same time, the high intensity (high speed) flushing of the surface of the urea sensor causes the urea on the sensor surface to flow rapidly, affecting the stability of the sensor ultrasonic signal transmission.

[0009] The technical problem that needs to be solved in this application is to avoid the above negative effects to the greatest extent possible and ensure the normal operation of the urea pump. Utility Model Content

[0010] One purpose of the utility model is to provide a urea ultrasonic sensor debubbling device and a urea tank, which utilizes a diverter device to divide the overflow into two, adjust the flow directed to the urea sensor, control the flushing intensity, reduce the overflow back pressure, and avoid the negative impact caused by the overflow pipe.

[0011] In order to solve the above technical problems, the utility model provides a urea ultrasonic sensor debubbling device, including a diverter device arranged on an overflow pipe connected to a urea pump, which has a urea outlet leading to the sensor and a urea outlet for returning to the urea tank. The liquid overflowing from the urea pump is diverted through the two urea outlets, so that part of the urea aqueous solution directly returns to the urea tank, and part of the urea aqueous solution is led to the emitting surface and the reflecting surface of the ultrasonic sensor to remove bubbles that may be generated on the surface of the ultrasonic sensor.

[0012] Preferably, the flow diverter is arranged on the overflow pipe close to the overflow valve outlet.

[0013] Preferably, the diverter device is connected to the overflow valve outlet by setting a urea inlet, the urea inlet is connected to both the urea outlet leading to the sensor and the urea outlet returning to the urea tank, and the urea outlet returning to the urea tank is connected to the overflow pipe.

[0014] Preferably, the urea outlet flow rate leading to the sensor is smaller than the urea outlet flow rate returning to the urea tank.

[0015] Preferably, the flow ratio of the urea outlet flow leading to the sensor to the urea outlet flow returning to the urea tank is 1:4 to 1:1.

[0016] The utility model also provides a urea box, comprising the urea ultrasonic sensor debubbling device described in any one of the above items.

[0017] Preferably, the urea pump included in the urea tank is a top-mounted urea pump, a bottom-mounted urea pump, or a split-type urea pump.

[0018] The utility model at least has the following beneficial effects:

[0019] 1. The setting of the diversion device of the utility model makes most of the overflow flow back to the urea tank directly without passing through the overflow pipe. Even if the overflow pipe is temporarily blocked under certain accidental circumstances, it will not affect the overflow volume of the urea pump. At the same time, this setting also greatly reduces the overflow back pressure, does not affect the normal emptying and pressure building of the urea pump, and greatly reduces the failure rate of the urea pump.

[0020] 2. The setting of the diverter device of the utility model controls the urea flow rate on the surface of the ultrasonic urea sensor within a relatively suitable range by diverting the overflow of the urea pump, thereby avoiding the generation of bubbles when the urea liquid level is low, reducing interference with the ultrasonic signal, and reducing excessive scouring damage to the sensor surface coating.

[0021] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a schematic diagram of the assembly relationship of the urea pump, the overflow valve, the urea tank and the urea sensor of the overhead urea pump;

[0023] Figure 2 Schematic diagram of current technology using urea pump overflow to flush the sensor surface;

[0024] Figure 3 Current technology uses urea pump overflow to flush the sensor surface;

[0025] Figure 4 It is a schematic diagram of diverting the overflow of a urea pump disclosed in the utility model;

[0026] Figure 5 It is a partial schematic diagram of the overflow diversion of the urea pump disclosed in the utility model;

[0027] Figure 6 This is a schematic diagram of the diversion device disclosed in the utility model.

[0028] Description of reference numerals:

[0029] 100: urea pump; 110: connecting chuck; 120: liquid inlet pipe; 130: injection pipe; 140: overflow valve; 150: overflow pipe; 200: urea tank; 220: urea (aqueous solution); 300: urea sensor; 310: ultrasonic emitting surface of quality (concentration) sensor; 320: ultrasonic reflecting surface of quality (concentration) sensor; 330: ultrasonic emitting surface of liquid level sensor; 400: diverter; 410: urea inlet; 420: urea outlet for returning to urea tank; 430: urea outlet leading to sensor. DETAILED DESCRIPTION

[0030] In order to better understand the purpose, structure and function of the utility model, the utility model is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0031] It should be noted that, in the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0032] The utility model discloses a device that utilizes the overflow of a urea pump to remove bubbles on the surface of an ultrasonic urea sensor. Taking an integrated top-mounted urea pump as an example, the implementation case is as follows:

[0033] The present application discloses a device for diverting overflow of a urea pump, such as Figures 2-3 As shown in FIG. 1 , part of the overflowed urea from the overflow valve 140 of the urea pump is led to the vicinity of the ultrasonic urea sensor 300 (installed at the bottom of the urea tank) through the pipeline (overflow pipe) 150, so that the urea on the surface of the sensor flows and takes away (expels) the bubbles that may be attached to the surface of the sensor; in order to avoid the blockage of the overflow pipe in some cases, and also to adjust the intensity (speed) of the urea flow near the sensor and reduce the overflow back pressure, as shown in FIG. Figure 4 As shown, a diverter device 400 is installed at the overflow pipe 150 as close as possible to the outlet of the overflow valve 140, so that most of the overflowed urea is directly returned to the urea tank, and only a small part of the overflowed urea is led to the vicinity of the urea sensor 300 to flush the emitting surfaces 310 and 330 and the reflecting surface 320 of the sensor. Figure 5 shown.

[0034] Since the diverter device 400 is installed very close to the overflow valve 140, the overflow resistance (back pressure) can be minimized; meanwhile, the possibility of the overflow pipe 150 being blocked due to urea crystallization and freezing can be minimized.

[0035] The flow dividing device 400 can be any device that can divide the fluid into two according to a pre-designed ratio, for example, it can be a very simple structure, such as Figure 6 As shown, the overflow urea comes out of the overflow valve 140 and enters the interior of the diverter device through the urea inlet 410 of the diverter device 400, and then most of the urea flows back from the side into the urea outlet 420 of the urea tank and flows into the urea tank 200, leaving only a small amount of urea flowing out from the urea outlet 430 leading to the sensor below and being led to the urea sensor.

[0036] The size ratio of the two urea outlets 420 and 430 is designed according to the required flushing flow rate on the surface of the urea sensor, so that the liquid flow rate on the sensor surface is moderate, which will not damage the coating on its surface and will not affect the stability of ultrasonic signal transmission. Different products correspond to different ratios. The flow ratio of the urea outlet flow to the sensor and the urea outlet flow back into the urea tank is generally between 1:4 and 1:1. In fact, only a small local liquid flow (disturbance) is required to drive out bubbles on the surface of the urea sensor.

[0037] Although the above implementation cases take the top-mounted urea pump as an example, in fact, the utility model is also applicable to bottom-mounted and split-type urea pumps. For bottom-mounted urea pumps, the above overflow generally overflows upward, so the overflow pipe needs to be U-shaped and lead from top to bottom to the urea sensor. Compared with the top-mounted urea pump, the overflow pipe is more likely to be dehydrated or blocked in the pipe due to insufficient heating when the liquid level is low. For the split pump, except for the additional connecting pipe between the urea pump and the urea tank pipe, it is similar to the top-mounted pump. Therefore, this article will not go into details.

[0038] It can be understood that the present invention is described by some embodiments, and those skilled in the art know that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation mode. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, other modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to specific details and the illustrations shown and described here.

Claims

1. A urea ultrasonic sensor debubbling device, characterized in that: The invention comprises a flow diversion device arranged on an overflow pipe connected to the urea pump, which has a urea outlet leading to the sensor and a urea outlet returning to the urea tank. The liquid overflowing from the urea pump is diverted through the two urea outlets, so that part of the urea aqueous solution directly returns to the urea tank, and part of the urea aqueous solution is led to the emitting surface and the reflecting surface of the ultrasonic sensor to drive away bubbles that may be generated on the surface of the ultrasonic sensor.

2. The urea ultrasonic sensor debubbling device according to claim 1, characterized in that: The flow dividing device is arranged on the overflow pipe close to the outlet of the overflow valve.

3. The urea ultrasonic sensor debubbling device according to claim 1, characterized in that: The diverter device is connected to the overflow valve outlet by arranging a urea inlet, the urea inlet is connected to both the urea outlet leading to the sensor and the urea outlet returning to the urea tank, and the urea outlet returning to the urea tank is connected to the overflow pipe.

4. The urea ultrasonic sensor debubbling device according to claim 1, characterized in that: The urea outlet flow rate to the sensor is less than the urea outlet flow rate returning to the urea tank.

5. The urea ultrasonic sensor debubbling device according to claim 4, characterized in that: The flow ratio of the urea outlet flow leading to the sensor and the urea outlet flow returning to the urea tank is 1:4 to 1:

1.

6. A urea tank, characterized in that: The invention comprises the debubbling device for a urea ultrasonic sensor as described in any one of claims 1 to 5.

7. The urea tank according to claim 6, characterized in that: The urea pump included in the urea tank is a top-mounted urea pump, a bottom-mounted urea pump, or a split-type urea pump.

Images