WO2018188379A1 - Method for segmented voltage buildup of tail gas post-processing system - Google Patents

Abstract

A method for segmented voltage buildup of a tail gas post-processing system, at least comprising the following steps: S0: a step of determining whether an engine is started or not, and if the engine is started, executing step S1; S1: a first voltage buildup stage: driving a pump assembly to operate in a first pump speed, and detecting whether the outlet pressure of the pump assembly exceeds a threshold or not, if yes, executing step S3, and if not, executing step S2; S2: a second voltage buildup stage: driving the pump assembly to operate in a second pump speed, and detecting whether the outlet pressure of the pump assembly exceeds a threshold or not, if yes, executing step S3, and if not, executing step Sn; S3: a pressure maintenance stage: determining whether pressure maintenance is succeeded or not, if yes, succeeding in voltage buildup, and if not, executing step Sn; and Sn: if the first voltage buildup fails, driving the pump assembly for back suction, then performing the second voltage buildup, and determining whether the second voltage buildup is successful or not, if yes, succeeding in voltage buildup, and if not, failing in voltage buildup.

Description

Method for segmenting pressure of exhaust gas aftertreatment system

The present application claims the priority of the Chinese patent application filed on April 12, 2017, the application number is 201710237455.9, and the invention is entitled "Method for the segmentation of the exhaust gas aftertreatment system", the entire contents of which are incorporated by reference. In this application.

Technical field

The invention relates to a method for segmenting pressure of an exhaust gas aftertreatment system, and belongs to the technical field of engine exhaust aftertreatment.

Background technique

The exhaust gas of internal combustion engines, especially diesel engines, contains a large amount of nitrogen oxides and particulate matter, which causes great pollution to the atmosphere. Today's smog is frequent and visibility is reduced, and environmental quality is getting worse and worse. This has an inseparable relationship, which greatly affects human health. Purification of emissions is an urgent task, and all countries have specific environmental regulations to regulate this. As the state has increased its emphasis on the environment, various regulations have been issued to regulate the exhaust gas treatment of internal combustion engines.

The existing pressure-making strategy of the existing exhaust gas after-treatment system relies only on a certain value after calibration. This method has great limitations, such as the length of the pipeline, the performance of the urea pump, the injection aperture of the urea nozzle, and the return aperture. The construction pressure has a great influence, and it is even directly related to whether the construction pressure can be successful. For example, for a batch of urea pumps, some pumps can reach system pressure thresholds at lower speeds, while others require higher speeds. If a certain value after calibration is used, if the value is set lower, those pumps that require high speed tend to fail to build pressure; if the value is set higher, only low speed can be used to build pressure. Pumps that generate high pressures at such high speeds can cause impact on system piping.

Therefore, it is urgent to provide a new method of building pressure to solve the above problems.

Summary of the invention

It is an object of the present invention to provide a method of providing an intelligent pressure building function.

To achieve the above object, the present invention adopts the following technical solutions:

A method for segmenting pressure of an exhaust aftertreatment system, the exhaust aftertreatment system comprising a pump assembly and a nozzle assembly, the method comprising at least the following steps:

S0: a step of judging whether the engine has been started; if the engine is not started, stop building pressure of the pump assembly; if the engine has been started, proceed to step S1;

S1: the first stage of pressure: drive the pump assembly to operate at a first pump speed (PDC1), and detect whether the outlet pressure of the pump assembly exceeds a threshold, and if so, step S3; if not, step S2;

S2: second stage build pressure: driving the pump assembly to operate at a second pump speed (PDC2) higher than the first pump speed (PDC1), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed;

S3: pressure maintenance phase: judging whether the pressure maintenance is passed, if yes, the pressure is successfully established; if not, performing step Sn;

Sn: Failure to build the pressure for the first time, after driving the pump assembly back pumping, perform step S1 or S2 for secondary build pressure, and judge whether the secondary build pressure is successful. If yes, the build pressure is successful; if not, the build pressure fails.

As a further improvement of the technical solution of the present invention, after step S2 and before step Sn, the method further comprises the following steps:

S30: third stage build pressure: driving the pump assembly to operate at a third pump speed (PDC3) higher than the second pump speed (PDC2), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.

As a further improvement of the technical solution of the present invention, after step S30 and before step Sn, the method further comprises the following steps:

S40: The fourth stage builds pressure: driving the pump assembly to operate at a fourth pump speed (PDC4) higher than the third pump speed (PDC3), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.

As a further improvement of the technical solution of the present invention, after step S40 and before step Sn, the method further comprises the following steps:

S50: a fifth stage build pressure: driving the pump assembly to operate at a fifth pump speed (PDC5) higher than the fourth pump speed (PDC4), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.

As a further improvement of the technical solution of the present invention, after step S50 and before step Sn, the method further comprises the following steps:

S60: a sixth stage build pressure: driving the pump assembly to operate at a sixth pump speed (PDC6) higher than the fifth pump speed (PDC5), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.

As a further improved technical solution of the present invention, the method further comprises the step of detecting the number of the nozzle assemblies, wherein the nozzle assembly is cooled by at least urea reflux, wherein:

If the detection fails or detects that the nozzle assembly is one or two, step S1 is performed;

If it is detected that the nozzle assembly is three, four or five, step S2 is performed;

If it is detected that the nozzle assembly is six or seven, step S30 is performed;

If it is detected that the nozzle assembly is eight or more, step S40 is performed.

As a further improvement of the technical solution of the present invention, before the first pressure failure is obtained, the step Sn further includes the step of determining whether the maximum time for establishing the pressure is exceeded, wherein if yes, the first pressure is failed; if not, the detection is performed. The step of the number of nozzle assemblies.

As a further improved technical solution of the present invention, in step S50, the nozzle assembly first duty ratio (IDC1) is driven to open; if the pressure build-up is successful, the nozzle assembly is immediately closed.

As a further improved technical solution of the present invention, in step S60, the nozzle assembly is driven to be opened with a second duty ratio (IDC2), and the second duty ratio (IDC2) is greater than the first duty ratio (IDC1) ); if the build pressure is successful, immediately close the nozzle assembly.

As a further improved technical solution of the present invention, in step S3, the power-down storage pressure exceeds the threshold value of the pump speed value (PDC).

As a further improved technical solution of the present invention, in the step S2, before the pressure is established in the second stage, the method further comprises the step of opening the nozzle assembly.

As a further improvement of the technical solution of the present invention, the pressure-building time of step S1 is T1, the pressure-building time of step S2 is T2, and the pressure-building time of step S30 is T3;

The step Sn further includes the step of determining whether the maximum time for establishing the pressure is exceeded, wherein if yes, the first pressure is failed; if not, the relationship between the pressure building time and T1, T2, and T3 is determined, wherein:

If the build time is not greater than T1, step S1 is performed;

If the build time is greater than T1 but not greater than T2, step S2 is performed;

If the build time is greater than T2, step S30 is performed.

As a further improved technical solution of the present invention, the exhaust aftertreatment system includes an integrated device of a pump and a nozzle, the integrated device including a housing, the pump assembly being at least partially mounted in the housing, the nozzle assembly Cooperating with the pump assembly, wherein the housing includes an inlet passage upstream of the pump assembly and in communication with the pump assembly, and an outlet passage downstream of the pump assembly and in communication with the pump assembly, The outlet passage is in communication with the nozzle assembly; the pump assembly includes a motor coil for driving a pump, a magnetic body that interacts with the motor coil, and a first gear assembly and a second gear assembly that mesh with each other, wherein The first gear assembly includes a first gear, the second gear assembly includes a second gear, the first gear and the second gear are in mesh with each other, and the housing is provided to receive the first gear and the a gear groove of the second gear, one side of the gear groove is provided with an inlet chamber communicating with the inlet passage, and the other side of the gear groove is provided to communicate with the outlet passage A liquid chamber; a coil for driving the nozzle the nozzle assembly comprises a nozzle.

As a further improved technical solution of the present invention, the integrated device further includes a heat shield at least partially surrounding the casing.

As a further improved technical solution of the present invention, the integrated device further includes a controller for independently controlling the pump assembly and the nozzle assembly, the controller including a circuit board, the motor coil and the nozzle The coils are each connected to the circuit board.

As a further improved technical solution of the present invention, the integrated device includes an overflow element connected between the outlet passage and the inlet passage.

As a further improved technical solution of the present invention, the exhaust gas aftertreatment system includes an integrated device of a pump and a nozzle, the integrated device includes the pump assembly and the nozzle assembly; and the pump assembly includes a motor casing assembly a magnetic cover assembly at least partially located within the motor housing assembly and a pump housing assembly mated with the motor housing assembly; the motor housing assembly including an electromagnetic shield and at least partially located a motor coil within the electromagnetic shield; the magnetic shield assembly including a metal cover at least partially inserted into the motor coil and a rotor housed within the metal cover; the pump housing assembly including the pump An inlet passage upstream and in communication with the pump and an outlet passage downstream of the pump and in communication with the pump, the outlet passage being in communication with the nozzle assembly; the pump housing assembly further including intermeshing a first gear assembly and a second gear assembly, wherein the first gear assembly includes a first gear shaft and a first gear, and the second gear assembly includes a second gear shaft a second gear, the first gear and the second gear mesh with each other, the rotor is fixed on the first gear shaft; the pump housing assembly is provided to receive the first gear and the first a gear groove of the two gears, one side of the gear groove is provided with an inlet chamber communicating with the inlet passage, and the other side of the gear groove is provided with an outlet chamber communicating with the outlet passage; the nozzle The assembly includes a nozzle coil for driving the nozzle.

As a further improved technical solution of the present invention, the integrated device further includes a heat shield at least partially surrounding the pump assembly and the nozzle assembly; the motor housing assembly includes the pump assembly and the nozzle assembly Separately controlled controllers each comprising a circuit board, the motor coils and the nozzle coils being connected to the circuit board.

As a further improved technical solution of the present invention, the metal cover is further provided with an anti-freeze body above the rotor, and the anti-freeze body can be compressed to absorb the expansion volume generated by the urea icing.

As a further improved technical solution of the present invention, the pump assembly further includes an elastic body housed in the metal cover and located under the rotor, the elastic body being capable of being compressed to absorb an expansion volume generated by urea freezing. .

As a further improved technical solution of the present invention, the pump housing assembly further includes a first anti-freeze rod located in the liquid inlet chamber and a second anti-freeze rod located in the liquid discharge chamber, the Both the antifreeze bar and the second antifreeze bar are capable of being compressed when the urea is frozen.

According to a further improvement of the present invention, the nozzle assembly includes a magnetic portion that interacts with the nozzle coil, a first sleeve that at least partially houses the magnetic portion, and a valve needle portion that is located below the magnetic portion. a second sleeve that at least partially houses the valve needle portion, a spring that acts between the magnetic portion and the valve needle portion, a valve seat that engages with the valve needle portion, and a valve seat that is separate from the valve seat a swirling sheet abutting against the valve seat, the swirling fin being provided with a plurality of swirling grooves.

As a further improved technical solution of the present invention, the nozzle coil is located at a periphery of the magnetic portion, the valve needle portion is provided with a valve needle, and the first sleeve is fixed with the second sleeve to form a surrounding a space around a periphery of the valve needle portion, the valve needle is provided with a through hole communicating with the space, and the second sleeve is provided with a communication groove that communicates the space with the swirl groove, The valve seat is provided with an injection hole that cooperates with the valve needle.

As a further improvement of the technical solution of the present invention, the motor casing assembly is provided with an injection molded connector, the connector is electrically connected to the circuit board, and the circuit board is mounted with a plurality of electronic components, The motor housing assembly also includes a heat sink pad overlying the surface of the electronic component.

As a further improved technical solution of the present invention, the magnetic cover assembly includes a plate portion under the metal cover, and the plate portion is fixed to the pump housing assembly by a plurality of screws.

As a further improved technical solution of the present invention, the pump housing assembly includes a first housing, the first housing including a first upper surface, a first lower surface, and a first side, wherein the first upper surface a first annular groove, a first island portion surrounded by the first annular groove, and a first sealing ring received in the first annular groove, the plate portion pressing down against the first seal a first positioning hole penetrating the first lower surface and a second positioning hole penetrating the first lower surface, the pump assembly being included in the first positioning hole a first bushing and a second bushing received in the second positioning hole, wherein the first gear shaft is inserted into the first bushing, and the second gear shaft is inserted into the second bushing in.

According to a further improvement of the present invention, the first island portion further includes a first flow guiding groove extending through the first upper surface and communicating with the second positioning hole, and extending through the first upper surface a first outlet hole communicating with the liquid chamber; the first upper surface further provided with a sensor receiving hole located at a side of the first island portion for receiving the sensor, the integrated device including a sensor for detecting temperature and pressure The first housing is further provided with a second outlet hole that communicates with the sensor receiving hole.

As a further improved technical solution of the present invention, the first housing is provided with an overflow element receiving groove, and the integrated device is provided with an overflow element installed in the overflow element receiving groove; when the outlet passage is When the pressure is above a set value, the overflow element opens to return a portion of the urea solution to the inlet passage.

As a further improved technical solution of the present invention, the pump housing assembly includes a second housing that is below the first housing and is connected to the first housing, and the second housing includes a second The upper surface and the second lower surface, the gear groove extends through the second upper surface and the second lower surface.

As a further improved technical solution of the present invention, the pump housing assembly includes a third housing located below the second housing and connected to the second housing, the third housing including a body portion And a raised portion extending downward from the body portion, wherein the body portion is provided with a third upper surface, the third upper surface is provided with a third annular groove and a third surrounded by the third annular groove Island Department.

As a further improved technical solution of the present invention, the nozzle assembly includes a nozzle assembly and a water-cooling base sleeved outside the nozzle assembly, the water-cooling base is provided with a mounting groove, a first cooling passage, and the a second cooling passage spaced apart from the cooling passage and an end cap sealed at a periphery of the mounting groove, the nozzle assembly forming a communication between the end cover and the second sleeve to communicate with the first cooling An annular cooling channel of the passage and the second cooling passage, the first cooling passage is connected to the inlet joint for injection of engine coolant, and the second cooling passage is connected to the outlet joint for the engine coolant to flow out.

The invention aims at the problem that the existing exhaust gas after-treatment system frequently fails to build pressure, and through the analysis of the influencing factors of the pressure-building failure and a large number of experiments, the intelligent pressure-building strategy is made. The intelligent pressure-building strategy is not affected by these factors such as the length of the pipeline, the performance of the urea pump, the injection aperture of the urea nozzle, and the recirculation aperture, which greatly improves the success rate of the construction. Moreover, when the system state is switched from the built pressure to the injection state, the pressure transition is smooth, ensuring stable injection pressure and improved injection accuracy.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of the exhaust gas aftertreatment system of the present invention applied to the treatment of engine exhaust.

Figure 2 is a schematic diagram of the integrated device of Figure 1.

3 is a perspective view of an integrated device of the present invention in an embodiment.

Figure 4 is a plan view of Figure 3.

Figure 5 is a partial exploded perspective view of the integrated device of the present invention with the pump assembly separated from the nozzle assembly.

Figure 6 is a partially exploded perspective view of the integrated device of the present invention with the motor housing assembly separated.

Figure 7 is a perspective view of the motor housing assembly of Figure 6.

Figure 8 is a partially exploded perspective view of the motor housing assembly of Figure 6.

Figure 9 is a further exploded perspective view of Figure 8 with the motor coils separated.

Figure 10 is a further exploded perspective view of the motor housing assembly of Figure 6 removed.

Figure 11 is a further exploded perspective view of Figure 10.

Figure 12 is a further exploded perspective view of Figure 11 .

Figure 13 is a further exploded perspective view of Figure 12 with the pump housing assembly, nozzle assembly, end caps and the like separated.

Figure 14 is a partially exploded perspective view of the pump housing assembly of Figure 13;

Figure 15 is an exploded perspective view of the first housing of Figure 14 and the components thereon.

Figure 16 is an exploded perspective view of Figure 15 at another angle.

Figure 17 is a perspective view of the first housing of Figure 15.

Figure 18 is a perspective view of Figure 17 at another angle.

Figure 19 is a plan view of Figure 18.

Figure 20 is a plan view of Figure 17 .

Figure 21 is a schematic cross-sectional view taken along line C-C of Figure 20.

Figure 22 is a cross-sectional view taken along line D-D of Figure 20.

Figure 23 is a cross-sectional view taken along line E-E of Figure 20.

Figure 24 is a cross-sectional view taken along line F-F of Figure 20.

Figure 25 is a perspective view showing the first housing of Figure 14 removed.

Figure 26 is a partially exploded perspective view of Figure 25.

Figure 27 is a plan view of Figure 25.

Figure 28 is a further exploded perspective view of Figure 25.

Figure 29 is a perspective view of the nozzle assembly of Figure 13;

Figure 30 is a cross-sectional view taken along line G-G of Figure 29.

Figure 31 is an exploded perspective view of Figure 29.

Figure 32 is a further exploded perspective view of Figure 31.

Figure 33 is a cross-sectional view taken along line A-A of Figure 4 .

Figure 34 is a cross-sectional view taken along line B-B of Figure 4 .

Figure 35 is a schematic cross-sectional view taken along line H-H of Figure 33.

Figure 36 is an exploded perspective view of the integrated device of the present invention.

Figure 37 is a flow chart showing the method of segmenting the exhaust gas aftertreatment system in the first embodiment of the present invention.

Figure 38 is a flow chart showing the method for segmenting the exhaust gas aftertreatment system in the second embodiment of the present invention.

detailed description

Referring to FIG. 1, the present invention discloses an exhaust aftertreatment system 100 that can be applied to treat exhaust gas from engine 10 to reduce emissions of hazardous materials to meet emission regulations. The exhaust aftertreatment system 100 includes an exhaust aftertreatment injection system 200 and an exhaust aftertreatment packaging system 300, wherein the injection system 200 includes means for pumping urea solution from the urea tank 201 (as indicated by arrow X) and An integrated device 1 that injects urea solution into the intake or exhaust of the engine 10 (e.g., into the exhaust pipe 106 or within the packaging system 300); the packaging system 300 includes a mixer 301 located downstream of the integrated device 1 And a carrier 302 located downstream of the mixer 301. Of course, in some embodiments, the mixer may not be provided, or two or more mixers may be provided. The carrier 302 can be, for example, a selective catalytic reduction (SCR) or the like.

The engine 10 has an engine coolant circulation circuit. Referring to FIG. 1, in the illustrated embodiment of the present invention, the engine coolant circulation circuit includes a first circulation circuit 101 (shown by a thick arrow Y) and a second circulation circuit 102 (refer to a thin arrow Z). The first circulation loop 101 is configured to cool the integrated device 1 to reduce its risk of being burned out by a high temperature engine exhaust; the second circulation loop 102 is used to heat the urea tank 201, To achieve the heating and defrosting function. It can be understood that, in the first circulation loop 101, the integrated device 1 is provided with an inlet joint 103 for the engine coolant to flow in and an outlet joint 104 for the engine coolant to flow out; in the second circulation loop 102, it is provided There is a control valve 105 to open or close the control valve 105 under suitable conditions to effect control of the second circulation loop 102. The urea tank 201 is provided with a heating rod 202 connected to the second circulation loop 102 to heat and thaw the urea solution by using the temperature of the engine coolant.

The integrated device 1 of the present invention will be described in detail below.

Referring to FIG. 2, in principle, the integrated device 1 of the present invention integrates the functions of the urea pump 11 and the urea nozzle 12. The urea pump 11 includes, but is not limited to, a gear pump, a diaphragm pump, a plunger pump, a vane pump, and the like. It should be understood that the term "integrated" as used herein means that the urea pump 11 and the urea nozzle 12 can be mounted as a single device on the intake or exhaust pipe; or the urea pump 11 and the urea nozzle 12 are close to each other and pass through. A shorter connecting pipe is connected and can be regarded as a device as a whole.

In addition, the exhaust aftertreatment system 100 of the present invention is further provided with a controller 13. The controller 13 is capable of independently controlling the urea pump 11 and the urea nozzle 12. It will be appreciated that the controller 13 may be integrated with or separate from the integrated device 1. Referring to FIG. 2, in the illustrated embodiment of the present invention, the controller 13 is integrated in the integrated device 1 to achieve high integration of parts and improve installation convenience of the client.

The integrated device 1 is provided with a housing 14 for accommodating the urea pump 11 and the urea nozzle 12. The embodiment shown in Figure 2 is only a rough representation of the housing 14. For example, in one embodiment, the housing 14 is shared by the urea pump 11 and the urea nozzle 12; in another embodiment, the housing 14 is divided into a first housing that mates with the urea pump 11. And a second housing that cooperates with the urea nozzle 12, the first housing and the second housing being assembled together to form a unitary body. Of course, in other embodiments, the housing 14 can also be divided into several to mate with the urea pump 11 and/or the urea nozzle 12. The housing 14 is provided with an inlet passage 15 connected between the urea tank 201 and the urea pump 11, and an outlet passage 16 connected between the urea pump 11 and the urea nozzle 12. It should be noted that the term "inlet" in the "inlet passage 15" and "outlet" in the "outlet passage 16" are referenced by the urea pump 11, that is, the upstream of the urea pump 11 is the inlet, and the urea pump 11 The downstream is the exit. The outlet passage 16 is in communication with the urea nozzle 12 to pump a urea solution to the urea nozzle 12. It can be understood that the inlet passage 15 is located upstream of the urea pump 11 and is a low pressure passage; the outlet passage 16 is located downstream of the urea pump 11 and is a high pressure passage.

In addition, the integrated device 1 is provided with a temperature sensor for detecting the temperature. The temperature sensor may be arranged to communicate with the inlet channel 15 and/or the outlet channel 16; or the temperature sensor may be arranged to be mounted at any location of the integrated device 1. The signal detected by the temperature sensor is transmitted to the controller 13, and the control algorithm designed by the controller 13 based on the input signal and other signals can improve the injection accuracy of the urea nozzle 12. The integrated device 1 is also provided with a pressure sensor for detecting pressure, the pressure sensor being in communication with the outlet passage 16 to detect the pressure in the high pressure passage of the outlet of the urea pump 11. Due to the integrated design of the present invention, the distance of the internal passage is relatively short, so that the position of the pressure sensor can be considered to be relatively close to the urea nozzle 12. The advantage of this design is that the pressure measured by the pressure sensor is relatively close to the pressure in the urea nozzle 12, which improves the accuracy of the data and thus improves the injection accuracy of the urea nozzle 12. In an embodiment of the invention, the temperature sensor and the pressure sensor are two components; in the illustrated embodiment of the invention, the temperature sensor and the pressure sensor are one component (ie, the sensor 174) , detailed later, but at the same time has the function of detecting temperature and pressure.

Referring to FIG. 2, the integrated device 1 is further provided with an overflow element 173 connected between the outlet passage 16 and the inlet passage 15. The overflow element 173 includes, but is not limited to, a relief valve, a safety valve, or an electrically controlled valve or the like. The function of the overflow element 173 is to open the overflow element 173 when the pressure in the high pressure passage is higher than the set value, to release the urea solution located in the high pressure passage into the low pressure passage or directly return to the In the urea tank 201, pressure regulation is achieved.

In order to drive the urea pump 11, the urea pump 11 is provided with a motor coil 111 that communicates with the controller 13. In order to drive the urea nozzle 12, the urea nozzle 12 is provided with a nozzle coil 121 that communicates with the controller 13.

The controller 13 communicates with the temperature sensor and the pressure sensor to transmit a temperature signal and a pressure signal to the controller 13. Of course, in order to enable precise control, the controller 13 can also receive other signals, such as signals from the CAN bus that are related to engine operating parameters. In addition, the controller 13 can also obtain the rotational speed of the urea pump 11. Of course, the acquisition of the rotational speed signal can be achieved by a corresponding rotational speed sensor 175 (hardware) or by a control algorithm (software). The controller 13 independently controls the urea pump 11 and the urea nozzle 12. The advantage of such control is that the effect of the action of the urea pump 11 on the urea nozzle 12 can be reduced to achieve a relatively high control accuracy.

In addition, under certain operating conditions, since the exhaust of the engine has a higher temperature, and the urea nozzle 12 is generally mounted on the exhaust pipe, the urea nozzle 12 needs to be cooled and/or Insulation. The integrated device 1 is also provided with a cooling assembly for this purpose, which cools the urea nozzle 12 by means of a cooling medium. The cooling medium includes, but is not limited to, air, and/or engine coolant, and/or lubricating oil, and/or urea, and the like. Referring to Figure 2, the illustrated embodiment of the present invention uses water cooling, i.e., cooling the urea nozzle 12 with engine coolant. A cooling passage 141 for circulating the engine coolant is provided in the housing 14. Referring to FIG. 1, in the illustrated embodiment of the present invention, the integrated device 1 is further provided with a mounting seat 107 mounted on the exhaust pipe 106 and a partition fixed to the mounting base 107. Heat shield 109. In the illustrated embodiment of the present invention, the mount 107 is mounted on the exhaust pipe 106; of course, it can be understood that in other embodiments, the mount 107 can also be directly mounted on the package system 300. .

Referring to FIG. 2, the main working principle of the integrated device 1 is as follows:

The controller 13 drives the urea pump 11 to operate. The urea solution in the urea tank 201 is sucked into the urea pump 11 through the inlet passage 15, and after being pressurized, is sent to the urea nozzle 12 through the outlet passage 16. Among them, the controller 13 collects and/or calculates required signals such as temperature, pressure, pump speed, and the like. When the injection condition is reached, the controller 13 sends a control signal to the urea nozzle 12, such as energizing the nozzle coil 121, and by controlling the movement of the valve needle to effect urea injection. The controller 13 sends a control signal to the urea pump 11 to control its rotational speed, thereby stabilizing the pressure of the system. In the illustrated embodiment of the invention, the controller 13 independently controls the urea pump 11 and the urea nozzle 12.

Referring to FIGS. 3 through 36, in the illustrated embodiment of the present invention, the integrated device 1 includes a pump assembly 18 and a nozzle assembly 19. Referring to Figure 5, the nozzle assembly 19 is at least partially inserted into the pump assembly 18 and welded together.

Referring to Figures 3 through 5, in the illustrated embodiment of the invention, the pump assembly 18 includes a motor housing assembly 181, and a magnetic cover assembly 6 at least partially disposed within the motor housing assembly 181. And a pump housing assembly 182 that mates with the motor housing assembly 181.

Referring to FIGS. 7-10, the motor housing assembly 181 includes an electromagnetic shield 183, a motor coil 111 at least partially located within the electromagnetic shield 183, and a controller 13. In the illustrated embodiment of the present invention, the electromagnetic shielding cover 183 is made of a metal material to reduce external interference of internal electronic components and the like, and also reduce the influence of internal electronic components on other external electronic devices. . The motor housing assembly 181 also includes a housing 2 that is injection molded at the periphery. The casing 2 includes a casing cavity 21 for covering the controller 13 and at least a portion of the pump assembly 18, a through hole 22 communicating with the casing cavity 21, and being fixed in the through hole 22. Waterproof venting cover 24. The motor coil 111 is electrically connected to the controller 13 . In the illustrated embodiment of the invention, the controller 13 includes a circuit board 131 having a plurality of electronic components disposed thereon. The electronic component generates heat during operation, causing the air around it to expand. The present invention solves the problem of crushing the chip and/or the electronic component due to air expansion by providing the waterproof and permeable cover 24, and can also Waterproof effect. In addition, the waterproof venting cover 24 can improve the environment in which the controller 13 is placed to enable it to meet operating conditions.

In the illustrated embodiment of the invention, the circuit board 131 is annular and is provided with a central aperture 135 in the middle. The cover 2 is injection molded with a connector 132 connected to the circuit board 131. In addition, the motor housing assembly 181 further includes a heat dissipation pad 130 covering the surface of the electronic component. In this way, the temperature of the electronic component can be uniformized by the heat dissipation pad 130, thereby avoiding the burning of the electronic component due to local overheating.

The magnetic cover assembly 6 includes a metal cover 62 at least partially inserted into the motor coil 111, a plate portion 61 located below the metal cover 62, and a rotor 72 and the like housed in the metal cover 62. The metal cover 62 protrudes upward from the plate portion 61. The metal cover 62 passes upward through the central aperture 135 of the circuit board 131 and is at least partially inserted into the motor coil 111. Referring to FIG. 10, the plate portion 61 is tightened to the pump housing assembly 182 by a plurality of screws 133 to secure the magnetic cover assembly 6. In addition, referring to FIG. 33 and FIG. 34, the metal cover 62 is further provided with an anti-freeze body 70 located above the rotor 72, and the anti-freeze body 70 can be compressed and absorbed when the urea is frozen. Expand the volume to avoid being damaged by freezing. In the illustrated embodiment of the invention, the anti-freeze body 70 is mounted in a sleeve which is then rolled against the top of the metal cover 62 for securing. The pump assembly 18 also includes an elastomer 71 housed within the metal shroud 62 and below the rotor 72, the elastomer 71 being also compressible to absorb the expanded volume created by urea icing. Referring to FIG. 34, the motor coil 111 is sleeved on the periphery of the metal cover 62.

The pump housing assembly 182 includes a first housing 3, a second housing 4, and a third housing 5 that are stacked one above another. In the illustrated embodiment of the invention, the first housing 3, the second housing 4, and the third housing 5 are each made of a metal material. The housing 14 includes the first housing 3, the second housing 4, and the third housing 5.

In the illustrated embodiment of the present invention, the urea pump 11 is a gear pump including the motor coil 111, the metal cover 62, the elastic body 71 and the rotor 72 located in the metal cover 62, and located at the A first seal ring 73 below the metal cover 62, and a first gear assembly 74 and a second gear assembly 75 that are in mesh with each other are described. Since the gear pump can establish a relatively large working pressure, it is advantageous to increase the flow rate of the urea nozzle 12. In addition, the gear pump can also reverse, which helps to evacuate the residual urea solution and reduce the risk of urea crystallization.

Referring to FIG. 14 to FIG. 28, in the illustrated embodiment of the present invention, the first housing 3, the second housing 4, and the third housing 5 are machined parts and are fixed by bolts 66. together. The first housing 3 is provided with a card slot 34 on the side and an O-ring 35 held in the slot 34. In the illustrated embodiment of the invention, the first housing 3 and the motor housing assembly 181 are secured together by rolling or welding and are sealed by an O-ring 35.

The first housing 3 includes a first upper surface 31, a first lower surface 32, and a first side surface 33, wherein the first upper surface 31 is provided with a first annular groove 311 and surrounded by the first annular groove 311 The first island portion 312. The first annular groove 311 is configured to receive the first sealing ring 73. The sheet portion 61 presses down the first seal ring 73 to effect sealing. The first lower surface 32 is provided with a second annular groove 325 and a second island portion 326 surrounded by the second annular groove 325. The second annular groove 325 is for receiving the second sealing ring 731 (as shown in FIG. 16).

The first island portion 312 is provided with a first positioning hole 3121 extending through the first lower surface 32, a second positioning hole 3122 extending through the first lower surface 32, and penetrating the first upper surface 31 and A first outlet hole 3123 communicating with the outlet passage 16 and a first guide groove 3124 penetrating the first upper surface 31 and communicating with the second positioning hole 3122. The urea pump 11 is provided with a first sleeve 76 housed in the first positioning hole 3121 and a second sleeve 77 housed in the second positioning hole 3122. The first housing 3 further includes a plurality of first assembly holes 318 through which the bolts 66 pass, the first assembly holes 318 extending through the first upper surface 31 and the first lower surface 32. The first upper surface 31 further includes a sensor receiving hole 313 located at a side of the first island portion 312 for receiving the sensor 174. The sensor 174 has a function of detecting temperature and pressure. The first housing 3 is further provided with a second outlet hole 3125 that communicates with the outlet passage 16 and the sensor receiving hole 313.

Further, as shown in Fig. 24, the first casing 3 is provided with a liquid inlet passage 332 which penetrates the first side surface 33 to be connected to the urea joint 331. Referring to FIG. 15, FIG. 16, and FIG. 34, the urea joint 331 includes a filter 3311 near the outer side and an antifreeze element 3312 near the inner side, wherein the filter net 3311 can filter impurities in the urea solution. The antifreeze element 3312 is capable of absorbing the expansion volume as the urea freezes, thereby reducing the risk of freezing. The first housing 3 is provided with a connecting hole 3127 that penetrates the first lower surface 32 and communicates with the liquid inlet passage 332. The first outlet hole 3123 and the connection hole 3127 are both perpendicular to the liquid inlet passage 332. The first positioning hole 3121, the second positioning hole 3122, and the connecting hole 3127 all penetrate downward through the second island portion 326. The first lower surface 32 is provided with a first relief groove 321 that communicates with the first positioning hole 3121 and the second positioning hole 3122 to ensure pressure balance. The first relief groove 321 is located on the second island portion 326. In addition, the first housing 3 is further provided with a receiving cavity 322 extending downwardly through the first lower surface 32 for receiving at least a portion of the nozzle assembly 19. Referring to FIG. 21 and FIG. 22 , the receiving cavity 322 is in communication with the sensor receiving hole 313 . At the same time, the receiving cavity 322 is also in communication with the second outlet hole 3125. In the illustrated embodiment of the invention, the second outlet opening 3125 is inclined inside the first housing 3.

In addition, referring to FIGS. 14 to 16 , 22 , and 24 , the first casing 3 is further provided with an overflow element receiving groove 319 that communicates with the liquid inlet passage 332 and the receiving cavity 322 . The overflow element receiving groove 319 extends outward through the first side surface 33 to receive the overflow element 173. The overflow element 173 is a safety valve in the illustrated embodiment of the invention, the purpose of which is to ensure that the pressure in the high pressure passage in the integrated device 1 is within a safe range by means of pressure relief. In order to fix the overflow element 173, the first housing 3 is provided with a plug 5122 that fixes the overflow element 173.

Referring to FIG. 1, the urea joint 331 is in communication with the urea tank 201 through a urea connection pipe 333. In order to better achieve the heating and defrosting function, the exhaust gas aftertreatment system 100 may further be provided with a heating device 334 that heats the urea connection pipe 333. Referring to FIG. 24, in the illustrated embodiment of the present invention, the liquid inlet passage 332 extends horizontally into the interior of the first casing 3. Of course, in other embodiments, the liquid inlet channel 332 can also be at an angle.

Referring to FIGS. 25-27, the first gear assembly 74 includes a first gear shaft 741 and a first gear 742 fixed to the first gear shaft 741; the second gear assembly 75 includes a second gear shaft. 751 and a second gear 752 fixed to the second gear shaft 751, the first gear 742 and the second gear 752 mesh with each other. Referring to FIGS. 25-27, in the illustrated embodiment of the present invention, the first gear 742 is externally meshed with the second gear 752. In addition, the first gear shaft 741 is a drive shaft, the second gear shaft 751 is a driven shaft, and the first gear shaft 741 is higher than the second gear shaft 751. The upper end of the first gear shaft 741 passes through the first sleeve 76 and is fixed to the rotor 72. The upper end of the second gear shaft 751 is positioned in the second boss 77. When the motor coil 111 is energized, it interacts with the magnetic body 72, and the electromagnetic force drives the first gear shaft 741 to rotate, thereby driving the first gear 742 and the second gear 752 to rotate.

Referring to FIGS. 25 to 28 , the second housing 4 is located below the first housing 3 and is connected to the first housing 3 . In addition, for better positioning, a plurality of positioning pins 328 are further disposed between the first housing 3 and the second housing 4. The second housing 4 includes a second upper surface 41 , a second lower surface 42 , and a second upper surface 41 and a second lower surface 42 for receiving the first gear 742 and the second gear 752 . Gear groove 43. One side of the gear groove 43 is provided with an inlet chamber 431 communicating with the inlet passage 15, and the other side of the gear groove 43 is provided with an outlet chamber 432 communicating with the outlet passage 16. Specifically, the liquid inlet chamber 431 is in communication with the connection hole 3127, and the upper end of the liquid outlet chamber 432 is in communication with the first outlet hole 3123. In addition, in order to improve the frost resistance of the product, the second casing 4 is further provided with a first anti-freeze bar 441 located in the liquid inlet chamber 431 and a second anti-freeze bar located in the liquid outlet chamber 432. 442. The first antifreeze bar 441 and the second antifreeze bar 442 are both compressible when the urea is frozen.

In addition, the second housing 4 is further provided with a receiving hole 411 through which at least a part of the nozzle assembly 19 passes. The nozzle assembly 19 protrudes upward from the second upper surface 41 and is received in the receiving cavity 322. With this arrangement, a high pressure urea solution can be delivered to the urea nozzle 12. The second housing 4 further includes a plurality of second assembly holes 418 aligned with the first assembly apertures 318.

Referring to FIG. 28, the third housing 5 is located below the second housing 4 and is connected to the second housing 4. The third housing 5 includes a body portion 51, a boss portion 52 extending downward from the body portion 51, and a flange 53 extending outward from the body portion 51, wherein the flange 53 is provided with the A plurality of third assembly holes 531 are aligned with the second assembly holes 418 for the bolts 66 to pass through. The body portion 51 is provided with a third upper surface 511, and the third upper surface 511 is provided with a third annular groove 512 and a third island portion 513 surrounded by the third annular groove 512. The third annular groove 512 is for receiving the third sealing ring 732 (as shown in FIG. 33). The third island portion 513 is provided with a third positioning hole 5111 penetrating the third upper surface 511 and a fourth positioning hole 5112 penetrating the third upper surface 511. The third housing 5 is provided with a third sleeve 78 received in the third positioning hole 5111 and a fourth sleeve 79 received in the fourth positioning hole 5112 . The lower end of the first gear shaft 741 is positioned in the third bushing 78, and the lower end of the second gear shaft 751 is positioned in the fourth bushing 79.

In addition, the third island portion 513 is further provided with a second guiding groove 5114 and a third guiding groove 5115 on the third upper surface 511, wherein the second guiding groove 5114 and the third positioning hole 5111 In communication, the third guiding groove 5115 is in communication with the fourth positioning hole 5112. The second guiding groove 5114 and the third guiding groove 5115 are obliquely disposed inside the third casing 5. In the vertical direction, the second guiding groove 5114 and the third guiding groove 5115 are both in communication with the liquid outlet chamber 432, so as to ensure that the urea solution can enter the third positioning hole 5111 and the first The third sleeve 78 and the fourth sleeve 79 are lubricated in the four positioning holes 5112.

In operation, the urea solution enters the inlet channel 332 from the urea connection tube 333 and enters the inlet chamber 431 through the connection hole 3127; after the pressure of the gear pump, a portion of the high pressure urea solution passes upward through the first outlet port. 3123 enters into the metal cover 62, and another portion of the high pressure urea solution enters the second flow guiding groove 5114 and the third flow guiding groove 5115 downward; a portion of the urea solution located in the metal cover 62 is from the first guiding groove 3124 The second sleeve 77 enters the second sleeve 77 and enters the first sleeve 76 through the first relief groove 321 to improve the stability of the gear pump rotation and reduce wear; another portion of the urea solution located in the metal cover 62 is from the second The exit aperture 3125 enters the containment chamber 322 to flow to the nozzle assembly 19 while a portion of the urea solution flows to the overflow element 173. When the pressure is less than the set value of the overflow element 173, the overflow element 173 is closed; and when the pressure is greater than the set value of the overflow element 173, the overflow element 173 is opened, and part of the urea solution enters the liquid inlet passage 332 to Realize pressure relief.

It will be understood that in the illustrated embodiment of the invention, the inlet passage 15 includes a feed passage 332, a connecting bore 3127, and an inlet chamber 431. Since the inlet passage 15 is located upstream of the urea pump 11, it is called a low pressure passage. The outlet passage 16 includes a liquid outlet chamber 432, a first outlet hole 3123, a second outlet hole 3125, a receiving cavity 322, and the like. Since the outlet passage 16 is located downstream of the urea pump 11, it is referred to as a high pressure passage.

Referring to FIGS. 29 to 36, the nozzle assembly 19 includes a nozzle assembly 120 and a water-cooled base 190 that is sleeved outside the nozzle assembly 120. In the illustrated embodiment of the invention, the nozzle assembly 120 and the water-cooled base 190 together form a urea nozzle 12.

Referring to FIGS. 29 to 32, in the illustrated embodiment of the present invention, the nozzle assembly 120 includes a nozzle coil 121, a magnetic portion 81 that interacts with the nozzle coil 121, and the magnetic portion 81. The lower needle portion 82, a spring 83 that acts between the magnetic portion 81 and the needle portion 82, and a valve seat 84 (shown in FIG. 30) that is engaged with the valve needle portion 82. The nozzle coil 121 is located at a periphery of the magnetic portion 81. The nozzle assembly 120 further includes a first sleeve 811 at least partially receiving the magnetic portion 81 and a portion at least partially receiving the valve needle portion 82. Two sleeves 812. Additionally, the nozzle assembly 120 further includes a sleeve portion 122 that is sleeved around the periphery of the nozzle coil 121. The spring 83 is mounted in the magnetic portion 81 and the valve needle portion 82. The valve needle portion 82 is provided with a tapered portion 821 and a valve needle 822 extending downward from the tapered portion 821.

The first sleeve 811 is fixed with the second sleeve 812 to form a space 813 surrounding the periphery of the valve needle portion 82, and the valve needle 822 is provided with a communication with the space 813. Hole 814. The nozzle assembly 120 further includes a swirling vane 85 that is formed separately from the valve seat 84 and abuts against the valve seat 84. The swirling vane 85 is provided with a plurality of swirling grooves 851. The second sleeve 812 is provided with a communication groove 815 that communicates the space 813 with the swirl groove 851. The valve seat 84 is provided with an injection hole 841 that cooperates with the valve needle 822.

As shown in FIG. 30, the upper end of the magnetic portion 81 is sleeved with a fourth sealing ring 816 to seal against the inner wall of the receiving cavity 322. In addition, the nozzle assembly 120 further includes a terminal encapsulation portion 86 connected to the nozzle coil 121, and the terminal encapsulation portion 86 is sleeved with a fifth sealing ring 817.

The water-cooling base 190 includes a main body portion 91, a mounting groove 92 penetrating the main body portion 91 downward, and a mounting flange 93 extending outward from the main body portion 91. The mounting flange 93 is provided with a number of first mounting holes 931 for mounting the integrated device 1 to the exhaust pipe 106 or the packaging system 300. The main body portion 91 is provided with a fourth upper surface 911 and a fourth side surface 912. The fourth upper surface 911 is provided with a receiving cavity 94 for receiving the urea nozzle 12 and a recess 95 for receiving the convex portion 52.

The cooling passage 141 located in the water-cooled base 190 includes a first cooling passage 913 penetrating the fourth side surface 912 and a second cooling passage 914 spaced apart from the first cooling passage 913. The first cooling passage 913 is in communication with the inlet joint 103, and the second cooling passage 914 is in communication with the outlet joint 104. The water-cooling base 190 is provided with an end cap 96 (shown in FIG. 33) sealed to the periphery of the mounting groove 92. In the illustrated embodiment of the invention, the end cap 96 is welded within the mounting groove 92. As such, the water-cooled base 190 forms an annular cooling groove 916 that communicates between the first cooling passage 914 and the second cooling passage 915 between the end cover 96 and the second sleeve 812.

In the illustrated embodiment of the invention, the mounting flange 93 is integrally machined with the body portion 91. Of course, in other embodiments, the mounting flange 93 can also be fabricated separately from the body portion 91 and then welded together.

Compared with the prior art, the integrated device 1 of the present invention is an integrated design, which can omit or shorten the prior art urea pipe for connecting the pump and the nozzle, and can also save the prior art pump supply. The connectors between the various sensors and the harness in the unit can also be used without the need to heat the defrosting device, so the reliability is high. The integrated device 1 of the present invention is compact in structure and small in size, and is convenient for installation of various types of vehicles. In addition, in the integrated device 1 of the present invention, the internal fluid medium passage is short, the pressure drop is small, the dead volume between the pump and the nozzle is small, and the efficiency is high. The sensor 174 is close to the nozzle and the injection pressure is highly accurate. In addition, by independently controlling the pump and the nozzle separately, it is avoided that the action of the nozzle is driven by the action of the pump, thereby improving the accuracy of the control. Since the injection accuracy of the nozzle is improved, the amount of urea injected into the exhaust gas can be appropriately proportional to the nitrogen oxide compound, and the risk of crystallization due to excessive injection of urea is lowered. The integrated device 1 of the present invention can be water-cooled so that the temperature of the urea remaining in the integrated device 1 does not reach the crystallization point, and crystallization is less likely to occur.

Referring to FIGS. 37-38, the present invention relates to a method for segmenting a tail gas aftertreatment system 100, which includes at least the following steps:

S0: a step of judging whether the engine has been started; if the engine is not started, stop the pressure build of the pump assembly 18; if the engine has been started, then perform step S1;

S1: the first stage of pressure: drive the pump assembly 18 to operate at the first pump speed PDC1, and detect whether the outlet pressure of the pump assembly 18 exceeds a threshold, and if so, step S3; if not, step S2;

S2: second stage build pressure: driving the pump assembly 18 to operate at a second pump speed PDC2 higher than the first pump speed PDC1, and detecting whether the outlet pressure of the pump assembly 18 exceeds a threshold, and if so, executing Step S3; if no, step Sn is performed;

S3: pressure maintenance phase: judging whether the pressure maintenance is passed, if yes, the pressure is successfully established; if not, performing step Sn;

Sn: failure to build pressure for the first time, after driving the pump assembly 18 back pumping, performing step S1 or step S2 for secondary build pressure, and judging whether the secondary build pressure is successful, if yes, the build pressure is successful; if not, build pressure failure.

Referring to FIG. 37, in the illustrated embodiment of the present invention, after step S2 and before step Sn, the method further includes the following steps:

S30: third stage build pressure: driving the pump assembly 18 to operate at a third pump speed PDC3 higher than the second pump speed PDC2, and detecting whether the outlet pressure of the pump assembly 18 exceeds a threshold, and if so, executing Step S3; if no, step Sn is performed.

Referring to FIG. 37, in the illustrated embodiment of the present invention, after step S30 and before step Sn, the method further includes the following steps:

S40: The fourth stage builds pressure: driving the pump assembly 18 to operate at a fourth pump speed PDC4 higher than the third pump speed PDC3, and detecting whether the outlet pressure of the pump assembly 18 exceeds a threshold, and if so, executing Step S3; if no, step Sn is performed.

Referring to FIG. 37, in the illustrated embodiment of the present invention, after step S40 and before step Sn, the method further includes the following steps:

S50: fifth stage build pressure: driving the pump assembly 18 to operate at a fifth pump speed PDC5 higher than the fourth pump speed PDC4, and detecting whether the outlet pressure of the pump assembly 18 exceeds a threshold, and if so, executing Step S3; if no, step Sn is performed.

Referring to FIG. 37, in the illustrated embodiment of the present invention, after step S50 and before step Sn, the method further includes the following steps:

S60: sixth stage build pressure: driving the pump assembly 18 to operate at a sixth pump speed PDC6 higher than the fifth pump speed PDC5, and detecting whether the outlet pressure of the pump assembly 18 exceeds a threshold, and if so, executing Step S3; if no, step Sn is performed.

Referring to FIG. 37, in an embodiment of the present invention, the method further includes the step of detecting the number of the nozzle assemblies, wherein the nozzle assembly is cooled by at least urea reflux, wherein:

If the detection fails or detects that the nozzle assembly is one or two, step S1 is performed;

If it is detected that the nozzle assembly is three, four or five, step S2 is performed;

If it is detected that the nozzle assembly is six or seven, step S30 is performed;

If it is detected that the nozzle assembly is eight or more, step S40 is performed.

Referring to FIG. 37, in an embodiment of the present invention, before the failure to obtain the first pressure is established, the step Sn further includes the step of determining whether the maximum time for establishing the pressure is exceeded, and if yes, the first pressure is established. Failure; if not, the step of detecting the number of nozzle assemblies is performed.

In an embodiment of the invention, in step S50, the nozzle assembly first duty cycle IDC1 is driven to open; if the pressure build-up is successful, the nozzle assembly is immediately closed.

In an embodiment of the present invention, in step S60, the nozzle assembly is driven to open with a second duty ratio IDC2, the second duty ratio IDC2 is greater than the first duty ratio IDC1; Successfully, the nozzle assembly is immediately closed.

Referring to FIG. 37, in an embodiment of the present invention, in step S3, the pumping speed exceeds the threshold value of the pump speed value (PDC), so that the system directly goes to the last time when the system starts next time. The value of the successful pressure build.

Referring to FIG. 38, in the illustrated embodiment of the present invention, in step S2, the method further includes the step of opening the nozzle assembly before the second stage builds pressure.

Referring to FIG. 38, in the illustrated embodiment of the present invention, the pressure-building time of step S1 is T1, the pressure-building time of step S2 is T2, and the pressure-building time of step S30 is T3;

The step Sn further includes the step of determining whether the maximum time for establishing the pressure is exceeded, wherein if yes, the first pressure is failed; if not, the relationship between the pressure building time and T1, T2, and T3 is determined, wherein:

If the build time is not greater than T1, step S1 is performed;

If the build time is greater than T1 but not greater than T2, step S2 is performed;

If the build time is greater than T2, step S30 is performed.

Compared with the prior art, the invention adopts a segmented pressure building method, which can optimize the respective building pressures according to different pump components, and improves the probability of successful pressure building. In addition, the segmented pressure-building method does not allow the pump assembly that can successfully build pressure at low speeds to build pressure through very high speeds, thus avoiding pressure shocks and protecting the system.

The above embodiments are only intended to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of the present specification should be based on those skilled in the art, although the present specification has been described in detail with reference to the above embodiments. It should be understood by those skilled in the art that the present invention may be modified or equivalently modified by those skilled in the art without departing from the spirit and scope of the invention. Within the scope of the claims of the present invention.

Claims (31)

1. A method for segmenting pressure of an exhaust aftertreatment system, the exhaust aftertreatment system comprising a pump assembly and a nozzle assembly, the method comprising at least the following steps:

   S0: a step of judging whether the engine has been started; if the engine is not started, stop building pressure of the pump assembly; if the engine has been started, proceed to step S1;

   S1: the first stage of pressure: drive the pump assembly to operate at a first pump speed (PDC1), and detect whether the outlet pressure of the pump assembly exceeds a threshold, and if so, step S3; if not, step S2;

   S2: second stage build pressure: driving the pump assembly to operate at a second pump speed (PDC2) higher than the first pump speed (PDC1), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed;

   S3: pressure maintenance phase: judging whether the pressure maintenance is passed, if yes, the pressure is successfully established; if not, performing step Sn;

   Sn: Failure to build the pressure for the first time, after driving the pump assembly back pumping, perform step S1 or S2 for secondary build pressure, and judge whether the secondary build pressure is successful. If yes, the build pressure is successful; if not, the build pressure fails.
2. The method according to claim 1, wherein after the step S2 and before the step Sn, the method further comprises the following steps:

   S30: third stage build pressure: driving the pump assembly to operate at a third pump speed (PDC3) higher than the second pump speed (PDC2), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.
3. The method according to claim 2, wherein after the step S30 and before the step Sn, the method further comprises the following steps:

   S40: The fourth stage builds pressure: driving the pump assembly to operate at a fourth pump speed (PDC4) higher than the third pump speed (PDC3), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.
4. The method according to claim 3, wherein after the step S40 and before the step Sn, the method further comprises the following steps:

   S50: a fifth stage build pressure: driving the pump assembly to operate at a fifth pump speed (PDC5) higher than the fourth pump speed (PDC4), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.
5. The method of claim 4, wherein after the step S50 and before the step Sn, the method further comprises the following steps:

   S60: a sixth stage build pressure: driving the pump assembly to operate at a sixth pump speed (PDC6) higher than the fifth pump speed (PDC5), and detecting whether the outlet pressure of the pump assembly exceeds a threshold, if Step S3 is performed; if no, step Sn is performed.
6. The method of claim 5 wherein said method further comprises the step of detecting said nozzle assembly, said nozzle assembly being cooled using at least urea reflux, wherein:

   If the detection fails or detects that the nozzle assembly is one or two, step S1 is performed;

   If it is detected that the nozzle assembly is three, four or five, step S2 is performed;

   If it is detected that the nozzle assembly is six or seven, step S30 is performed;

   If it is detected that the nozzle assembly is eight or more, step S40 is performed.
7. The method of claim 6 wherein said step Sn further comprises the step of determining whether the maximum time to build pressure is exceeded, wherein if it is, the first pressure build fails; if not And performing the step of detecting the number of the nozzle assemblies.
8. The method of claim 4 wherein in step S50, said nozzle assembly first duty cycle (IDC1) is driven to open; if pressure build-up is successful, said nozzle assembly is immediately closed.
9. The method according to claim 5, wherein in step S60, the nozzle assembly is driven to open with a second duty ratio (IDC2), the second duty ratio (IDC2) being greater than the first duty ratio Air ratio (IDC1); if the build pressure is successful, immediately close the nozzle assembly.
10. The method of claim 1 wherein in step S3, the pumping speed exceeds a threshold value of a pump speed value (PDC).
11. The method of claim 1 wherein in step S2, prior to establishing the pressure in the second stage, the method further comprises the step of opening the nozzle assembly.
12. The method according to claim 2, wherein the pressure-building time of step S1 is T1, the pressure-building time of step S2 is T2, and the pressure-building time of step S30 is T3;

    The step Sn further includes the step of determining whether the maximum time for establishing the pressure is exceeded, wherein if yes, the first pressure is failed; if not, the relationship between the pressure building time and T1, T2, and T3 is determined, wherein:

    If the build time is not greater than T1, step S1 is performed;

    If the build time is greater than T1 but not greater than T2, step S2 is performed;

    If the build time is greater than T2, step S30 is performed.
13. The method of claim 1 wherein said exhaust aftertreatment system comprises an integrated device of a pump and a nozzle, said integrated device comprising a housing, said pump assembly being at least partially mounted within said housing The nozzle assembly mates with the pump assembly, wherein the housing includes an inlet passage upstream of the pump assembly and in communication with the pump assembly and downstream of the pump assembly and in communication with the pump assembly An outlet passage communicating with the nozzle assembly; the pump assembly including a motor coil for driving a pump, a magnetic body interacting with the motor coil, and a first gear assembly and a second gear that mesh with each other An assembly, wherein the first gear assembly includes a first gear, the second gear assembly includes a second gear, the first gear and the second gear are in mesh with each other, and the housing is configured to receive the first gear a gear groove of the gear and the second gear, one side of the gear groove is provided with a liquid inlet cavity communicating with the inlet passage, and the other side of the gear groove is provided with the outlet passage a discharge chamber; the nozzle assembly includes a nozzle coil for driving the nozzle.
14. The method of claim 13 wherein said integrated device further comprises a heat shield at least partially surrounding said housing.
15. The method of claim 13 wherein said integrated device is further provided with a controller for independently controlling said pump assembly and said nozzle assembly, said controller comprising a circuit board, said motor coil And the nozzle coil are both connected to the circuit board.
16. The method of claim 15 wherein said integrated means includes an overflow element coupled between said outlet passage and said inlet passage.
17. The method of claim 1 wherein said exhaust aftertreatment system comprises an integrated device of a pump and a nozzle, said integrated device comprising said pump assembly and said nozzle assembly; said pump assembly comprising a motor a housing assembly, a magnetic cover assembly at least partially located within the motor housing assembly, and a pump housing assembly mated with the motor housing assembly; the motor housing assembly including an electromagnetic shield and a motor coil at least partially located within the electromagnetic shield; the magnetic shield assembly including a metal cover at least partially inserted into the motor coil and a rotor housed within the metal cover; the pump housing assembly including An inlet passage upstream of the pump and in communication with the pump and an outlet passage downstream of the pump and in communication with the pump, the outlet passage being in communication with the nozzle assembly; the pump housing assembly Also included is a first gear assembly and a second gear assembly that are intermeshing, wherein the first gear assembly includes a first gear shaft and a first gear, and the second gear assembly includes a second gear And a second gear that meshes with the second gear, the rotor is fixed to the first gear shaft; the pump housing assembly is provided with the first gear and the a gear groove of the second gear, one side of the gear groove is provided with an inlet chamber communicating with the inlet passage, and the other side of the gear groove is provided with an outlet chamber communicating with the outlet passage; The nozzle assembly includes a nozzle coil for driving the nozzle.
18. The method of claim 17 wherein said integrated device further comprises a heat shield at least partially surrounding said pump assembly and said nozzle assembly; said motor housing assembly including said pump assembly and The nozzle assemblies are respectively independently controlled controllers, the controller including a circuit board, and the motor coils and the nozzle coils are both connected to the circuit board.
19. The method according to claim 17, wherein said metal cover is further provided with an antifreeze body above said rotor, said antifreeze body being compressible to absorb expansion caused by urea freezing volume.
20. The method of claim 19 wherein said pump assembly further comprises an elastomer housed within said metal cover and below said rotor, said elastomer being compressible to absorb urea by freezing The volume of expansion produced.
21. The method of claim 17 wherein said pump housing assembly further comprises a first antifreeze bar located in said inlet chamber and a second antifreeze bar located in said outlet chamber The first antifreeze bar and the second antifreeze bar are both compressible when the urea is frozen.
22. The method of claim 17 wherein said nozzle assembly includes a magnetic portion that interacts with said nozzle coil, a first sleeve that at least partially receives said magnetic portion, and a lower portion of said magnetic portion a valve needle portion, a second sleeve at least partially receiving the valve needle portion, a spring acting between the magnetic portion and the valve needle portion, a valve seat engaged with the valve needle portion, and the valve The seat is separately formed and abuts against the swirling fin on the valve seat, and the swirling fin is provided with a plurality of swirling grooves.
23. The method according to claim 22, wherein said nozzle coil is located at a periphery of said magnetic portion, said valve needle portion is provided with a valve needle, and said first sleeve is fixed to said second sleeve Forming a space surrounding a periphery of the valve needle portion, the valve needle is provided with a through hole communicating with the space, and the second sleeve is provided with a communication between the space and the swirl groove a groove, the valve seat being provided with an injection hole that cooperates with the valve needle.
24. The method according to claim 18, wherein said motor casing assembly is provided with an injection molded connector, said connector being electrically connected to said circuit board, said circuit board being mounted with a plurality of electronic components In the device, the motor housing assembly further includes a heat dissipation pad covering the surface of the electronic component.
25. The method of claim 17 wherein said magnetic shroud assembly includes a panel portion under said metal cover, said panel portion being secured to said pump housing assembly by a plurality of screws.
26. The method of claim 25 wherein said pump housing assembly includes a first housing, said first housing including a first upper surface, a first lower surface, and a first side, wherein said The first upper surface is provided with a first annular groove, a first island portion surrounded by the first annular groove, and a first sealing ring received in the first annular groove, and the plate portion is pressed downward a first sealing ring; the first island portion is provided with a first positioning hole penetrating the first lower surface and a second positioning hole penetrating the first lower surface, and the pump assembly includes the first positioning hole a first bushing in a positioning hole and a second bushing received in the second positioning hole, wherein the first gear shaft is inserted into the first bushing, and the second gear shaft is inserted into the In the second sleeve.
27. The method according to claim 26, wherein said first island portion further comprises a first flow guiding groove extending through said first upper surface and communicating with said second positioning hole and extending through said first a first outlet hole having a surface and communicating with the liquid outlet chamber; the first upper surface is further provided with a sensor receiving hole located at a side of the first island portion for receiving the sensor, and the integrated device includes a sensor Detecting temperature and pressure; the first housing is further provided with a second outlet opening in communication with the sensor receiving hole.
28. The method according to claim 27, wherein said first casing is provided with an overflow member receiving groove, and said integrated device is provided with an overflow member installed in said overflow member receiving groove; When the pressure of the outlet passage is above a set value, the overflow element opens to return a portion of the urea solution to the inlet passage.
29. The method of claim 26 wherein said pump housing assembly includes a second housing located below said first housing and coupled to said first housing, said second housing The body includes a second upper surface and a second lower surface, the gear groove extending through the second upper surface and the second lower surface.
30. The method of claim 29 wherein said pump housing assembly includes a third housing below said second housing and coupled to said second housing, said third housing The body includes a body portion and a protrusion extending downward from the body portion, wherein the body portion is provided with a third upper surface, the third upper surface is provided with a third annular groove, and the third annular groove is Surrounded by the third island.
31. The method of claim 23, wherein the nozzle assembly comprises a nozzle assembly and a water-cooled base that is sleeved outside the nozzle assembly, the water-cooled base is provided with a mounting slot, a first cooling passage, a second cooling passage spaced apart from the first cooling passage and an end cap sealed at a periphery of the mounting groove, the nozzle assembly forming a communication between the end cover and the second sleeve An annular cooling groove of the first cooling passage and the second cooling passage, the first cooling passage is connected to the inlet joint for injection of engine coolant, and the second cooling passage is connected with the outlet joint for engine cooling The liquid flows out.

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