CN209959322U

CN209959322U - Urea pump assembly

Info

Publication number: CN209959322U
Application number: CN201821731446.1U
Authority: CN
Inventors: 李智文; J·幕恩希; 周骁; 吕鹏
Original assignee: Continental Automotive Wuhu Co Ltd
Current assignee: Vitesco Automotive Wuhu Co Ltd
Priority date: 2018-10-24
Filing date: 2018-10-24
Publication date: 2020-01-17
Anticipated expiration: 2028-10-24

Abstract

The utility model relates to a urea pump assembly, include: a housing; an end cap assembled to the housing; a urea suction inlet; a urea nozzle; an electrical connector; a bidirectional gear pump located at least partially inside the housing and having a liquid inlet and a liquid outlet; the urea spraying device comprises a urea suction pipeline and a urea spraying pipeline, wherein two ends of the urea suction pipeline are respectively connected with a urea suction inlet and a liquid inlet, and the urea spraying pipeline is respectively connected with a liquid outlet and a urea nozzle. According to the utility model discloses a urea pump assembly has that spare part is few, compact structure, and urea sprays the precision height, and the pressure side spare part receives the little advantage of urea crystallization back expansion stress influence.

Description

Urea pump assembly

Technical Field

The utility model relates to an automobile exhaust handles the field, especially relates to a urea pump assembly for diesel engine exhaust processing system.

Background

When an internal combustion engine of an automobile, such as a diesel engine, is operated, nitrogen oxides (NOx) are generated with an excessive amount of oxygen in many cases, thereby causing environmental pollution. In order to meet the increasingly stringent emission requirements and reduce the emission of nitrogen oxides, NOx in the exhaust gas needs to be reduced into nitrogen and water, and usually, before the exhaust gas enters the catalyst, an aqueous urea solution is injected into the exhaust gas as a reducing agent to reduce the NOx, and the operation is specifically realized by pumping the exhaust gas into an exhaust pipeline after urea is absorbed from a urea tank by a urea pump.

The urea pump assembly on the market at present adopts the structure of one-way pump (for example diaphragm pump) plus switching-over valve to realize the function of urea injection and suck-back more, and the main shortcoming of this kind of design is that the part is many, and the structure is complicated, and measurement accuracy is not high, can not eliminate the shortcoming such as the influence of remaining urea crystallization to the system.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a compact structure, the measurement accuracy is high to can effectively reduce the urea pump assembly of urea crystallization to spare part harm.

The utility model provides a urea pump assembly includes: a housing; an end cap assembled to the housing such that an accommodating space is formed inside thereof; a urea suction inlet; a urea nozzle; an electrical connector; a bidirectional gear pump located at least partially inside the housing and having a liquid inlet and a liquid outlet; the urea spraying device comprises a urea suction pipeline and a urea spraying pipeline, wherein two ends of the urea suction pipeline are respectively connected with a urea suction inlet and a liquid inlet, and the urea spraying pipeline is respectively connected with a liquid outlet and a urea nozzle.

Preferably, the axial direction of the bidirectional gear pump is parallel to the axial direction of the urea nozzle.

Preferably, the urea spraying device further comprises a return pipeline and a urea return opening, wherein the return pipeline is communicated with the urea spraying pipeline and the urea return opening respectively.

Preferably, the urea tank further comprises a calibration component, the calibration component is located in the return pipeline, and a hole-shaped structure is formed on the calibration component, and the urea in the return pipeline can return to the urea tank through the hole-shaped structure.

Preferably, the urea spraying device further comprises a manifold assembly, wherein the manifold assembly is provided with a first connecting port and a second connecting port, the manifold assembly is matched with the bidirectional gear pump and covers a liquid inlet and a liquid outlet of the bidirectional gear pump, the first connecting port is respectively communicated with the urea suction pipeline and the liquid inlet, and the second connecting port is respectively communicated with the urea spraying pipeline and the liquid outlet.

Preferably, an expansion stress absorbing member is further included, the expansion stress absorbing member being located on the urea injection pipe.

Preferably, the urea injection device further comprises a pressure sensor mounted on the urea injection pipe, and the expansion stress absorbing member is located on the urea injection pipe between the liquid outlet and the pressure sensor.

Preferably, the expansion stress absorbing member has an axial direction perpendicular to the flow direction of the urea liquid.

Preferably, the urea quality sensor further comprises a urea quality sensor printed circuit board positioned in an inner accommodating space formed by the shell and the end cover.

Preferably, the electronic device further comprises a main printed circuit board positioned in the inner accommodating space formed by the shell and the end cover.

Preferably, a urea screen is also included, which forms part of the urea intake duct.

Preferably, the cooling device further comprises a cooling liquid inflow pipe and a cooling liquid outflow pipe formed on the housing.

Preferably, the cooling device further comprises a cooling liquid screen arranged on the cooling liquid inflow pipeline.

Preferably, the cooling liquid control device further comprises a cooling liquid control valve for controlling the opening and closing of the cooling liquid inflow pipeline.

Compared with the prior art, the utility model provides a urea pump assembly has that spare part is few, compact structure, and assembly process is simple, and urea sprays the precision height, and nozzle department atomization effect is good, and the pressure side spare part receives the little advantage of urea crystallization back expansion stress influence.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. In the drawings:

FIG. 1 is an exploded view of a urea pump assembly according to the present invention;

FIG. 2 is a schematic perspective view of the urea pump assembly shown in FIG. 1;

FIG. 3 is another perspective view of the urea pump assembly shown in FIG. 1;

FIG. 4 is a cross-sectional view of the urea pump assembly shown in FIG. 1;

FIG. 5 is a schematic perspective view of the bidirectional gear pump shown in FIG. 1;

FIG. 6 is a schematic perspective view of the manifold assembly shown in FIG. 1;

FIG. 7 is a top perspective view of the urea pump assembly shown in FIG. 1.

Detailed Description

A urea pump assembly according to an implementation of the present invention will be described below by way of example with reference to the accompanying drawings.

The main function and function of the urea pump assembly are to inject urea in a urea tank assembled with the urea pump assembly into an exhaust pipeline of an engine according to given pressure and flow rate according to information fed back by an Engine Control Unit (ECU), so as to reduce the content of NOx.

As shown in fig. 1 to 7, a urea pump assembly of the present invention includes: a housing 1, wherein the housing 1 includes a housing periphery 101 and a housing bottom 102, the housing periphery 101 and the housing bottom 102 may be integrally formed, or may be two components fixed together by a connecting member (for example, by screws); the end cover 2 is matched with the shell 1 so that a containing space can be formed inside the end cover 2 and the shell 1 for containing other components of the urea pump assembly, and particularly, the end cover 2 can be fixed on the periphery 101 of the shell through a connecting piece; urea intake 3 (shown in fig. 3); a urea nozzle 4; an electrical connector 5; a bidirectional gear pump 6, the bidirectional gear pump 6 being at least partially located inside the housing 1 and housed in a space formed by both the housing 1 and the end cover 2, and having a liquid inlet 61 and a liquid outlet 62; a urea suction pipe 7 and a urea injection pipe 8, both ends of the urea suction pipe 7 are respectively connected to the urea suction port 3 and the liquid inlet 61, and the urea injection pipe 8 is respectively connected to the liquid outlet 62 and the urea nozzle 4.

Wherein, the electrical connector 5 is used for providing electrical and/or signal connection for the bidirectional gear pump 6 and other parts in the urea pump assembly. During the operation of the urea pump assembly, the bidirectional gear pump 6 enters a first operation mode and provides a first pressure supply according to an instruction from a control unit (e.g., an ECU or a control unit inside the urea pump assembly), and at this time, urea sucked from the urea suction port 3 enters the urea suction pipe 7 and the liquid inlet 61, enters the urea injection pipe 8 through the liquid outlet 62, and is finally sprayed out through the urea nozzle 4 into an engine exhaust pipe; when the urea pump assembly needs to empty the residual urea inside, the bidirectional gear pump 6 enters a second working mode (reverse suck-back) according to an instruction from the control unit and provides a second pressure supply, at this time, the urea remaining inside the bidirectional gear pump 6 and in the urea suction pipeline 7 and the urea injection pipeline 8 is sucked back into the urea tank (not shown in the figure) through the urea suction port 3, so that the residual urea is emptied, and urea crystallization inside the pipeline is avoided.

Further, as shown in fig. 7, in view of realizing a compact structure of the urea pump assembly, the bidirectional gear pump 6 is specifically arranged in the following manner: the axial direction of the bidirectional gear pump 6 is parallel to the axial direction of the urea nozzle 4.

Further, as shown in fig. 4, the urea pump assembly further includes a return pipe 9, a urea return port 10, and a calibration component 11, where the return pipe 9 is respectively communicated with the urea injection pipe 8 and the urea return port 10; the calibration part 11 is located in the return line 9 and the calibration part 11 is formed with a hole-like structure (not shown in the figure). The function and function of the return pipeline 9 are to discharge the urea passing through the calibration component 11 into the urea tank through the urea return port 10; specifically, the urea can flow through the porous structure and then flow back to the urea tank. The function and function of the calibration component 11 are specifically as follows: first, the pressure is established in an auxiliary way, which is implemented as follows: because the diameter of the hole-shaped structure is smaller than that of the return pipe 9, the calibration component 11 can assist the bidirectional gear pump 6 to quickly build working pressure meeting the urea injection requirement, so that the urea sprayed out from the urea nozzle 4 has a better atomization effect; secondly, auxiliary calibration is carried out, and the implementation principle is as follows: by acquiring the temperature in the exhaust pipe and the information of the NOx sensor, the ECU can calculate the injection quantity A of the required urea flow, and in addition, the urea flow B of the calibration component 11 under the specific pressure and the specific temperature is fixed, so the urea flow required to be provided by the bidirectional gear pump 6 can be obtained by adding B to A; then, by searching a theoretical Map (flow and rotation speed curve) of the gear pump built in a PCB (such as a main printed circuit board 16), the control rotation speed of the bidirectional gear pump 6 can be obtained, and then the demand of the system is quickly responded; if the performance of the bidirectional gear pump 6 deviates from the theoretical model, the actual rotating speed of the bidirectional gear pump 6 can be adjusted by adjusting the flow of the calibration component 11 (compensating the error into the calibration component), so as to meet the output flow requirement of urea, thereby realizing the precision compensation of the bidirectional gear pump 6, further realizing the precise metering and quantitative supply of urea injection amount, and improving the injection precision. In order to prevent the urea in the urea tank from being sucked into the urea pump assembly when the bidirectional gear pump 6 reversely sucks, a check valve (not shown) is provided in the calibration part 11 to prevent the urea from being sucked from the urea tank through the urea return pipe 9.

Further, as shown in fig. 1, 4, 6 and 7, in order to ensure the effective connection among the urea suction pipe 7, the bidirectional gear pump 6 and the urea injection pipe 8 and fix the bidirectional gear pump 6, the urea pump assembly further includes a manifold assembly 12 located in the accommodating space between the housing 1 and the end cover 2, the manifold assembly 12 has a first connection port 121 and a second connection port 122, the manifold assembly 12 is installed in cooperation with the bidirectional gear pump 6 and covers the liquid inlet 61 and the liquid outlet 62 of the bidirectional gear pump 6, the first connection port 121 is respectively communicated with the urea suction pipe 7 and the liquid inlet 61, and the second connection port 122 is respectively communicated with the urea injection pipe 8 and the liquid outlet 62.

Further, since the density is decreased and the volume is expanded after urea is crystallized, as shown in fig. 1 and 7, in order to absorb the expansion volume (expansion stress) of urea crystals and avoid the crystallization from adversely affecting the pump critical components, the urea pump assembly further includes an expansion stress absorbing member 13, the material of the expansion stress absorbing member 13 is preferably rubber and is located on the urea injection pipe 8; as shown in fig. 6 and 7, preferably, the expansion stress absorbing member 13 is mounted on the urea injection pipe 8 through a first support structure 123 on the manifold assembly 12; preferably, the expansion stress absorbing member 13 has an axial direction perpendicular to the flow direction of the urea liquid (not shown in the figure) in consideration of optimization of the spatial layout.

Further, as shown in fig. 1 and 7, the urea pump assembly further includes a pressure sensor 14, the pressure sensor 14 is mounted on the urea injection pipe 8, as shown in fig. 6 and 7, and preferably, the pressure sensor 14 is mounted on the urea injection pipe 8 through a second support structure 124 on the manifold assembly 12. The function and function of the pressure sensor 14 is: the pressure in the urea injection pipeline 8 close to the urea nozzle 4 side is monitored in real time, the monitoring result is fed back to the control processing unit in the urea pump assembly, and the rotating speed of the bidirectional gear pump 6 is adjusted and controlled in real time through the processing and analysis of the control processing unit, so that the aim of accurately injecting urea is fulfilled, and a better injection atomization effect is obtained.

Further, since the piping of the liquid outlet 62 and the pressure sensor 14 is the urea pressure side where urea crystal is generated, which has a greater adverse effect on the pump assembly, the expansion stress absorbing member 13 may be provided on the urea injection pipe 8 between the liquid outlet 62 and the pressure sensor 14, as shown in fig. 7, so as to reduce the adverse effect of crystal expansion stress on key components as much as possible.

Further, as shown in fig. 1, the urea pump assembly further includes a main printed circuit board 16 located in the internal receiving space formed by the housing 1 and the end cap 2, and the main printed circuit board 16 may be a control processing unit for collecting and processing signals (such as pressure signals, temperature signals, ECU feedback signals, etc.) fed back by various sensors and other electronic components, and determining and controlling the rotation speed of the bidirectional gear pump 6 to achieve the purpose of precise dosage injection and suck back.

Further, as shown in fig. 1 and 7, the urea pump assembly further includes a urea quality sensor printed circuit board 15 located in the internal accommodating space formed by the housing 1 and the end cover 2, and configured to receive and process the collected urea quality signal in the urea tank and send the signal to the ECU.

Further, as shown in fig. 1, 2, 3 and 7, the urea pump assembly further includes a urea strainer 17, which forms a part of the urea suction duct 7, for filtering impurities in the urea.

Further, as shown in fig. 1, 2, 3 and 7, the urea pump assembly further includes a cooling liquid inflow pipe 18 and a cooling liquid outflow pipe 19 formed on the housing 1, wherein the housing internal pipe is not fully shown in the drawings. The cooling water from, for example, an engine, flows into the interior of the urea pump assembly through the cooling water inflow conduit 18, and flows out of the cooling water outflow conduit 19 through an external circulation line (not shown) inserted into the urea tank, and functions to heat the urea pump assembly and the urea in the urea tank with the engine cooling water to prevent urea from crystallizing.

Further, as shown in fig. 1, 3 and 7, the urea pump assembly further includes a coolant screen 20 disposed on the coolant inflow pipe 18 for filtering impurities in the coolant.

Further, as shown in fig. 1 and 2, the urea pump assembly further includes a coolant control valve 21 for controlling opening and closing of the coolant inflow pipe 18.

Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited thereto. Various changes and modifications can be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention is to be determined by the appended claims.

Claims

1. Urea pump assembly, its characterized in that includes:

a housing (1); an end cap (2), the end cap (2) being fitted to the housing (1) such that a receiving space is formed inside both; a urea inlet (3); a urea nozzle (4); an electrical connector (5);

a bidirectional gear pump (6), the bidirectional gear pump (6) being located at least partially inside the housing (1) and having a liquid inlet (61) and a liquid outlet (62); the axial direction of the bidirectional gear pump (6) is parallel to the axial direction of the urea nozzle (4);

the urea spraying device comprises a urea suction pipeline (7) and a urea spraying pipeline (8), wherein two ends of the urea suction pipeline (7) are respectively connected with a urea suction port (3) and a liquid inlet (61), and the urea spraying pipeline (8) is respectively connected with a liquid outlet (62) and a urea nozzle (4).

2. Urea pump assembly according to claim 1, characterized in that it further comprises a return duct (9) and a urea return opening (10), the return duct (9) communicating with the urea injection duct (8) and the urea return opening (10), respectively.

3. Urea pump assembly according to claim 2, characterized in that it further comprises a calibration part (11), which calibration part (11) is located in the return line (9), and in that a hole-like structure is formed in the calibration part (11), through which hole-like structure the urea in the return line (9) can flow back into the urea tank.

4. Urea pump assembly according to claim 1, characterized in that it further comprises a manifold assembly (12), the manifold assembly (12) having a first connection port (121) and a second connection port (122), and the manifold assembly (12) being fitted with the bidirectional gear pump (6) and covering the liquid inlet (61) and the liquid outlet (62) of the bidirectional gear pump (6), the first connection port (121) being in communication with the urea suction line (7) and the liquid inlet (61), respectively, and the second connection port (122) being in communication with the urea injection line (8) and the liquid outlet (62), respectively.

5. Urea pump assembly according to claim 1, characterized in that it further comprises an expansion stress absorbing part (13), which expansion stress absorbing part (13) is located on the urea injection pipe (8).

6. Urea pump assembly according to claim 5, characterized in that it further comprises a pressure sensor (14), which pressure sensor (14) is mounted on the urea injection conduit (8), the expansion stress absorbing member (13) being located on the urea injection conduit (8) between the liquid outlet (62) and the pressure sensor (14).

7. Urea pump assembly according to claim 5, characterized in that the axial direction of the expansion stress absorbing element (13) is perpendicular to the urea liquid flow direction.

8. Urea pump assembly according to claim 1, characterized in that it further comprises a urea quality sensor printed circuit board (15) in the inner receiving space formed by the housing (1) and end cap (2).

9. Urea pump assembly according to claim 1, characterized in that it further comprises a main printed circuit board (16) located in the inner receiving space formed by the housing (1) and end cap (2).

10. Urea pump assembly according to claim 1, characterized in that it further comprises a urea screen (17) which forms part of the urea suction conduit (7).

11. Urea pump assembly according to claim 1, characterized in that it further comprises a coolant inflow duct (18) and a coolant outflow duct (19) formed on the housing (1).

12. A urea pump assembly according to claim 11, further comprising a coolant screen (20) arranged on the coolant inflow conduit (18).

13. A urea pump assembly according to claim 11, further comprising a coolant control valve (21) for controlling the opening and closing of the coolant inflow conduit (18).