This application is a request for the priority of the Chinese patent application with the filing date of Jun. 6, 2016, application number of 201610392925.4, and title of invention of “Integrated Device, Exhaust-Gas Aftertreatment System, and Control Method”, the whole content of which is incorporated in this application by reference.
TECHNICAL FIELD
The present invention relates to an integrated device, an exhaust-gas aftertreatment system, and a control method, belonging to the technical field of engine exhaust-gas aftertreatment.
BACKGROUND ART
With the increasingly stringent emission standards of vehicles using internal combustion engines, in order to reduce the emission of harmful substances such as nitrogen oxides, selective catalytic reduction (SCR) is commonly used as the aftertreatment technology in the industry, and urea solutions are injected into the exhaust gas upstream of the SCR. A urea solution is hydrolyzed and pyrolyzed to produce ammonia and reacts with nitrogen oxides etc. to reduce the concentration of harmful substances.
At present, a urea injection system available on the market is usually an air auxiliary system or a non-air auxiliary system. Certainly, either system comprises a urea tank assembly, a pump supply unit connected to the urea tank assembly through a low-pressure pipe, a nozzle module connected to the pump supply unit through a high-pressure pipe, and a controller. The pump supply unit comprises a urea pump, a pressure sensor, etc., and the nozzle module comprises a urea nozzle, etc. The urea pump and the urea nozzle are spaced apart by a large distance, and are connected to each other through a urea pipe. In addition, a conventional urea injection system comprises a large number of components, and consequently is difficult to install and high-cost.
Therefore, it is urgent to provide a new technical solution.
SUMMARY OF THE PRESENT INVENTION
An objective of the present invention is to provide an integrated device capable of realizing downsizing of the device, an exhaust-gas aftertreatment system with the integrated device, and a control method.
In order to achieve the above objective, the present invention adopts the following technical solution:
- an integrated device comprising a pump and a nozzle, wherein
- the pump is for pumping a fluid medium to the nozzle, the nozzle is for injecting the fluid medium into the exhaust gas of the engine, the integrated device comprises a pump assembly and a nozzle assembly, wherein the pump assembly is provided with an accommodation compartment for at least partially accommodating the nozzle assembly; the pump assembly comprises a pump assembly housing and the pump matching the pump assembly housing, the pump assembly housing comprises an inlet passage located upstream of the pump and in communication with the pump, and an outlet passage located downstream of the pump and in communication with the pump, the outlet passage is in communication with the nozzle assembly, the pump assembly housing comprises an enclosure and a first housing located below the enclosure, the enclosure is provided with an enclosure cavity, and the first housing is provided with a pressure sensor accommodation hole that is in communication with the accommodation compartment; the pump assembly comprises a motor coil for driving the pump, a magnetic body for interacting with the motor coil, and a first gear assembly and a second gear assembly that mesh with each other, the first gear assembly comprises a first gear shaft and a first gear, the second gear assembly comprises a second gear shaft and a second gear, and the first gear meshes with the second gear; the nozzle assembly comprises a nozzle assembly housing and the nozzle matching the nozzle assembly housing, and the nozzle assembly further comprises a nozzle coil for driving the nozzle; the integrated device is further provided with a pressure sensor accommodated in the pressure sensor accommodation hole, the pressure sensor does not have an independent housing, and the enclosure serves as a housing of the pressure sensor.
As an improved technical solution of the present invention, the pump is a urea pump, the nozzle is a urea nozzle, and the fluid medium is a urea solution.
As an improved technical solution of the present invention, the pump is a fuel pump, the nozzle is a fuel nozzle, and the fluid medium is a fuel.
As an improved technical solution of the present invention, the integrated device comprises a controller connected to the motor coil and the nozzle coil, and the controller separately controls the urea pump and the urea nozzle independently.
As an improved technical solution of the present invention, the pressure sensor is in communication with the outlet passage, and the integrated device further comprises an overflow element connected between the outlet passage and the inlet passage.
As an improved technical solution of the present invention, the pressure sensor comprises a base plate, a circuit board fixed on the base plate, a conductive wire connected with the circuit board, and a protective cover fastened on the circuit board, wherein the base plate is provided with a plate body portion and a convex portion extending downward from the plate body portion, a sealing ring is arranged on the convex portion, and the convex portion is provided with a through-hole that penetrates downwards and passes through the plate body portion upwards.
As an improved technical solution of the present invention, the circuit board is provided with a chip at the position corresponding to the through-hole, and the protective cover is mounted on the periphery of the chip to protect the chip.
As an improved technical solution of the present invention, the protective cover is provided with a hole that is in communication with the chip, and the hole is in communication with the enclosure cavity.
As an improved technical solution of the present invention, the pump assembly housing is provided with a connecting plate assembly that matches the first housing, the connecting plate assembly comprises a plate portion and a metal cover that is fixed on the plate portion and protrudes upwards, the magnetic body is accommodated in the metal cover, and the motor coil is sleeved at the periphery of the metal cover.
As an improved technical solution of the present invention, the pump assembly further comprises an elastic body that is accommodated in the metal cover and is positioned below the magnetic body, and the elastic body can be compressed to absorb the volume expansion caused by the freezing of urea.
As an improved technical solution of the present invention, the plate portion is pressed downward against the pressure sensor.
As an improved technical solution of the present invention, the pump assembly housing is provided with a gear groove for accommodating the first gear and the second gear, the first gear meshes with the second gear, one side of the gear groove is provided with a liquid inlet cavity in communication with the inlet passage, and the other side of the gear groove is provided with a liquid outlet cavity in communication with the outlet passage.
As an improved technical solution of the present invention, the nozzle assembly comprises a magnetic portion for interacting with the nozzle coil, a valve needle portion located below the magnetic portion, a spring acting between the magnetic portion and the valve needle portion, and a valve seat matching the valve needle portion.
As an improved technical solution of the present invention, the nozzle coil is positioned at the periphery of the magnetic portion, the valve needle portion is provided with a valve needle, and the valve seat is provided with an injection hole matching the valve needle.
As an improved technical solution of the present invention, the valve seat comprises a swirling sheet welded on the nozzle assembly housing, the injection hole is arranged on the swirling sheet, and the swirling sheet is further provided with a plurality of swirling grooves that are in communication with the injection hole.
As an improved technical solution of the present invention, the integrated device is provided with a cooling assembly for cooling the urea nozzle, and the cooling assembly cools the urea nozzle by a cooling medium.
As an improved technical solution of the present invention, the controller is provided with a control board, the motor coil and the nozzle coil are electrically connected with the control board, the enclosure is provided with a through-hole in communication with the enclosure cavity and a waterproof and breathable cover fixed in the through-hole; the control board is welded with a wiring plug, and the wiring plug is exposed outside the enclosure.
As an improved technical solution of the present invention, the first housing comprises a first upper surface, a first lower surface, and a first side surface, wherein 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 accommodated in the first annular groove, the first sealing ring is positioned below the metal cover, the plate portion is pressed downward against the first sealing ring, the first island portion is provided with a first positioning hole that penetrates the first upper surface and the first lower surface, and a second positioning hole that penetrates the first lower surface, and the urea pump comprises a first shaft sleeve accommodated in the first positioning hole and a second shaft sleeve accommodated in the second positioning hole, wherein the first gear shaft is inserted into the first shaft sleeve, and the second gear shaft is inserted into the second shaft sleeve.
As an improved technical solution of the present invention, the first lower surface is provided with a first relief groove in communication with the first positioning hole and the second positioning hole.
As an improved technical solution of the present invention, the first island portion further comprises a first diversion groove that penetrates the first upper surface and is in communication with the second positioning hole and a first connecting hole that penetrates the first upper surface and is in communication with the inlet passage; the first housing is provided with a second connecting hole that penetrates the first lower surface and is in communication with the liquid inlet cavity and an outlet hole that penetrates the first lower surface and is in communication with the liquid outlet cavity.
As an improved technical solution of the present invention, the first housing is provided with an overflow element accommodation groove that is in communication with the outlet hole, and the integrated device is provided with an overflow element installed in the overflow element accommodation groove; when the pressure in the outlet passage is greater than a preset value, the overflow element is opened to return a part of the urea solution into the inlet passage.
As an improved technical solution of the present invention, the pump assembly housing comprises a second housing located below the first housing and connected with the first housing, the second housing comprises a second upper surface and a second lower surface, and the gear groove penetrates the second upper surface and the second lower surface.
As an improved technical solution of the present invention, the pump assembly housing comprises a third housing located below the second housing and connected with the second housing, the third housing comprises a body portion and a convex portion that extends 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 island portion surrounded by the third annular groove, the third island portion is provided with a third positioning hole and a fourth positioning hole that penetrate the third upper surface, and the third positioning hole and the fourth positioning hole extend into the convex portion; the urea pump comprises a third shaft sleeve accommodated in the third positioning hole and a fourth shaft sleeve accommodated in the fourth positioning hole, wherein the first gear shaft is inserted into the third shaft sleeve, and the second gear shaft is inserted into the fourth shaft sleeve.
As an improved technical solution of the present invention, the third island portion is provided with a second diversion groove and a third diversion groove that penetrate the third upper surface, wherein the second diversion groove is in communication with the third positioning hole, and the third diversion groove is in communication with the fourth positioning hole.
As an improved technical solution of the present invention, the nozzle assembly housing comprises a main body portion and an extension portion that extends downward from the main body portion, the main body portion is provided with an accommodation compartment for accommodating the urea nozzle, and a groove for accommodating the convex portion, and the accommodation compartment extends downward into the extension portion.
As an improved technical solution of the present invention, the nozzle assembly comprises a magnetic portion interacting with the nozzle coil, a valve needle portion connected with the magnetic portion, and a spring acting on the valve needle portion; the extension portion is provided with a current collection cavity that is in communication with the accommodation compartment, wherein the part of the magnetic portion that protrudes from the second upper surface is accommodated in the accommodation compartment.
As an improved technical solution of the present invention, the spring is installed in the magnetic portion and the valve needle portion, the valve needle portion is provided with a conical portion and a valve needle that extends downward from the conical portion, the valve needle extends into the current collection cavity, the magnetic portion is provided with a first communicating hole in communication with the accommodation compartment, the valve needle portion is provided with a second communicating hole in communication with the first communicating hole, and the conical portion is provided with a third communicating hole that allows the second communicating hole to communicate with the current collection cavity.
As an improved technical solution of the present invention, the nozzle assembly comprises a valve seat matching the valve needle, the valve seat comprises a swirling sheet welded on the extension portion, the swirling sheet is provided with an injection hole that matches the valve needle and a plurality of swirling grooves that are in communication with the injection hole, and the swirling grooves are in communication with the current collection cavity.
As an improved technical solution of the present invention, the nozzle assembly housing is provided with a first cooling passage, a second cooling passage spaced from the first cooling passage, and an end cover sealed at the periphery of the extension portion, the nozzle assembly housing forms an annular cooling groove that is in communication with the first cooling passage and the second cooling passage between the end cover and the extension portion, the first cooling passage is connected with an inlet connector for injection of an engine coolant, and the second cooling passage is connected with an outlet connector for outflow of an engine coolant.
The present invention also reveals the following technical solution:
- an exhaust-gas aftertreatment system, comprising an exhaust-gas
- aftertreatment injection system and an exhaust-gas aftertreatment housing system, wherein, the injection system comprises the integrated device, and the housing system comprises a carrier positioned downstream of the integrated device.
The present invention also reveals the following technical solution:
- a control method for an integrated device, wherein the integrated device is the aforementioned integrated device, and the control method comprises:
- driving the pump to suck the fluid medium into the pump through the inlet passage;
- after pressurization by the pump, conveying the fluid medium to the nozzle through the outlet passage;
- and when an injection condition is reached, energizing the nozzle coil and at least partially opening the nozzle to inject the fluid medium into the exhaust of the engine, wherein
- the motor coil and the nozzle coil are separately controlled.
Compared with the prior art, an integrated device comprising a pump and a nozzle according to the present invention integrates the pump and the nozzle very well, has a simple and compact structure, and greatly facilitates installations by customers. On the basis of integrating a urea pump and a urea nozzle in the integrated device, due to the improvement of control precision, the proportion of the urea injected into exhaust gas to nitrogen oxides can be made suitable, thus reducing the crystallization risk caused by excessive urea injection. In addition, the pressure sensor has no independent housing and is realized by an enclosure. Without affecting the function of the sensor, the size of the sensor can be reduced, and the downsizing of the integrated device can be realized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic diagram of an exhaust-gas aftertreatment system of the present invention used for treating engine exhaust.
FIG. 2 shows a schematic diagram of the integrated device in FIG. 1.
FIG. 3 shows a stereoscopic view of an integrated device according to an embodiment of the present invention.
FIG. 4 shows a stereoscopic view of FIG. 3 from another angle.
FIG. 5 shows a stereoscopic view of FIG. 3 from yet another angle.
FIG. 6 shows a front view of FIG. 3.
FIG. 7 shows a right view of FIG. 3.
FIG. 8 shows an upward view of FIG. 5.
FIG. 9 shows a top view of FIG. 5.
FIG. 10 shows a partial stereoscopic exploded view of an integrated device of the present invention, in which the pump assembly is separated from the nozzle assembly.
FIG. 11 shows a partial stereoscopic exploded view of the pump assembly in FIG. 10, in which the enclosure, the motor coil, and the waterproof and breathable cover are separated.
FIG. 12 shows a stereoscopic view in which the enclosure and the motor coil in FIG. 11 are assembled together.
FIG. 13 shows a stereoscopic exploded view of FIG. 12.
FIG. 14 shows a further stereoscopic exploded view of FIG. 11, in which the control board is separated.
FIG. 15 shows a stereoscopic exploded view after removal of the enclosure and the control board in FIG. 14, in which the connection plate assembly is separated.
FIG. 16 shows a stereoscopic view of the connecting plate assembly in FIG. 15.
FIG. 17 shows a stereoscopic exploded view of the connecting plate assembly in FIG. 15.
FIG. 18 shows a further stereoscopic exploded view of FIG. 15, in which the magnetic body, the elastic body, and the screws are separated.
FIG. 19 shows a further exploded view of FIG. 18, in which the first seal ring, the temperature sensor, and the pressure sensor are separated.
FIG. 20 shows a stereoscopic exploded view of the magnetic body, the elastic body, and the screws in FIG. 19.
FIG. 21 shows a sectional view of FIG. 20 from a certain angle after assembly.
FIG. 22 shows a stereoscopic view of the pressure sensor in FIG. 19.
FIG. 23 shows a stereoscopic view of FIG. 22 from another angle.
FIG. 24 shows a stereoscopic exploded view of FIG. 22.
FIG. 25 shows a sectional view along the C-C line in
FIG. 22.
FIG. 26 shows a partial stereoscopic exploded view after removal of the first seal ring, the temperature sensor, and the pressure sensor in FIG. 19, in which the first housing is separated.
FIG. 27 shows a stereoscopic exploded view of the first housing in FIG. 26.
FIG. 28 shows a stereoscopic exploded view of FIG. 27 from another angle.
FIG. 29 shows a stereoscopic view of a part of the first housing in FIG. 27.
FIG. 30 shows a stereoscopic view of FIG. 29 from another angle.
FIG. 31 shows a top view of FIG. 30.
FIG. 32 shows a sectional view along the D-D line in FIG. 31.
FIG. 33 shows a sectional view along the E-E line in FIG. 31.
FIG. 34 shows a sectional view along the F-F line in FIG. 31.
FIG. 35 shows a top view of FIG. 29.
FIG. 36 shows a sectional view along the G-G line in FIG. 35.
FIG. 37 shows a sectional view along the H-H line in FIG. 35.
FIG. 38 shows a sectional view along the I-I line in FIG. 35.
FIG. 39 shows a stereoscopic view after removal of the first housing in FIG. 26.
FIG. 40 shows a partial stereoscopic exploded view of FIG. 39, in which the first gear assembly and the second gear assembly are separated.
FIG. 41 shows a top view of FIG. 39.
FIG. 42 shows a stereoscopic exploded view after removal of the first gear assembly and the second gear assembly in FIG. 40.
FIG. 43 shows a stereoscopic view of the second housing in FIG. 42.
FIG. 44 shows a stereoscopic view of FIG. 43 from another angle.
FIG. 45 shows a stereoscopic view of the third housing assembly in FIG. 42.
FIG. 46 shows a top view of FIG. 45.
FIG. 47 shows a sectional view along the J-J line in
FIG. 46.
FIG. 48 shows a sectional view of along K-K line in FIG. 46.
FIG. 49 shows a partial stereoscopic exploded view of a nozzle assembly of the present invention.
FIG. 50 shows a partial exploded view of the urea nozzle in FIG. 49.
FIG. 51 shows a stereoscopic view of the nozzle assembly housing in FIG. 49.
FIG. 52 shows a partial exploded view of FIG. 51.
FIG. 53 shows a top view of a part of the nozzle assembly housing in FIG. 52.
FIG. 54 shows a sectional view along the L-L line in FIG. 53.
FIG. 55 shows a sectional view along the M-M line in FIG. 54.
FIG. 56 shows a sectional view along the N-N line in FIG. 54.
FIG. 57 shows a stereoscopic view of FIG. 53 from another angle.
FIG. 58 shows a stereoscopic exploded view of an integrated device of the present invention.
FIG. 59 shows a sectional view along the A-A line in FIG. 9.
FIG. 60 shows a sectional view along the O-O line in FIG. 59.
FIG. 61 shows a sectional view along the P-P line in FIG. 59.
FIG. 62 shows a sectional view along the Q-Q line in FIG. 60.
FIG. 63 shows a sectional view along the R-R line in FIG. 61.
FIG. 64 shows a sectional view along the B-B line in FIG. 9.
FIG. 65 shows a sectional view along the S-S line in FIG. 64.
SPECIFIC EMBODIMENTS
As shown in FIG. 1, the present invention discloses an exhaust-gas aftertreatment system 100 that can be used to treat the exhaust of the engine 10, thereby reducing the emission of harmful substances to meet the requirements of emission regulations. The exhaust-gas aftertreatment system 100 comprises an exhaust-gas aftertreatment injection system 200 and an exhaust-gas aftertreatment housing system 300, wherein the injection system 200 comprises an integrated device 1 for pumping a urea solution from the urea tank 201 (see the arrow X) and injecting the urea solution into the exhaust of the engine 10 (for example, into the exhaust pipe 106 or the housing system 300); the housing system 300 comprises a mixer 301 located downstream of the integrated device 1 and a carrier 302 located downstream of the mixer 301. Certainly, in some embodiments, it is also possible not to provide a mixer, or to provide two or more mixers. The carrier 302 can be, for example, a selective catalytic reduction (SCR) carrier.
The engine 10 is provided with an engine coolant circulation circuit. As shown in FIG. 1, in an embodiment of the present invention, the engine coolant circulation circuit comprises a first circulation circuit 101 (shown by the thick arrow Y) and a second circulation circuit 102 (shown by the thin arrow Z), wherein the first circulation circuit 101 is configured to cool the integrated device 1, thereby reducing its risk of being burned out by the high-temperature engine exhaust; the second circulation circuit 102 is configured to heat the urea tank 201, thereby realizing the function of pyrolysis. It is understandable that in the first circulation circuit 101, the integrated device 1 is provided with an inlet connector 103 for inflow of an engine coolant and an outlet connector 104 for outflow of an engine coolant; in the second circulation circuit 102, a control valve 105 is provided to open or close the control valve 105 under suitable conditions to realize the control of the second circulation circuit 102. The urea tank 201 is provided with a heating rod 202 connected to the second circulation circuit 102 to pyrolyze the urea solution using the temperature of the engine coolant.
The integrated device 1 of the present invention is described in detail below.
As shown in 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 can be, but is not limited to, a gear pump, a diaphragm pump, a plunger pump, or a vane pump. It should be understood that the term “integrated” used here means that the urea pump 11 and the urea nozzle 12 can be installed as a single device on an exhaust pipe; alternatively, the urea pump 11 and the urea nozzle 12 are close to each other and interconnected by a short connecting pipe, which can be regarded as a single device as a whole.
In addition, in order to control the urea pump 11 and the urea nozzle 12 independently, the exhaust-gas aftertreatment system 100 of the present invention is further provided with a controller 13. It can be understood that the controller 13 may be integrated with the integrated device 1 or provided apart from the integrated device 1. As shown in FIG. 2, in the illustrated embodiment of the present invention, the controller 13 is integrated in the integrated device 1 to achieve a high degree of integration of parts and improve the convenience of client installation.
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 FIG. 2 is only a rough illustration 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 matching the urea pump 11 and a second housing matching the urea nozzle 12, and the first housing and the second housing are assembled together to form a whole body. The housing 14 is provided with an inlet passage 15 that connects the urea tank 201 with the urea pump 11 and an outlet passage 16 that connects the urea pump 11 with the urea nozzle 12. It should be noted that the terms “inlet” in “inlet passage 15” and “outlet” in “outlet passage 16” used here are in reference to the urea pump 11. In other words, the upstream of the urea pump 11 is the inlet and the downstream of the urea pump 11 is the outlet. The outlet passage 16 is in communication with the urea nozzle 12 to pump a urea solution to the urea nozzle 12. It is understandable 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 171 for detecting a temperature. The temperature sensor 171 may be configured to communicate with the inlet passage 15 and/or the outlet passage 16; alternatively, the temperature sensor 171 may be configured to be installed at any position in the integrated device 1. A signal detected by the temperature sensor 171 is transmitted to the controller 13; the controller 13 can improve the injection accuracy of the urea nozzle 12 by a control algorithm designed on the basis of the input signal and other signals. The integrated device 1 is further provided with a pressure sensor 172 for detecting pressure, and the pressure sensor 172 is connected with the outlet passage 16 to detect the pressure in the high-pressure passage at the outlet of the urea pump 11. Because of the integrated design of the present invention, the internal passage is relatively short, and it can be considered that the pressure sensor 172 is close to the urea nozzle 12. An advantage of this design is that the pressure measured by the pressure sensor 172 is close to the pressure in the urea nozzle 12, which improves the data accuracy and the injection accuracy of the urea nozzle 12.
As shown in FIG. 2, the integrated device 1 is also provided with an overflow element 173 connected between the outlet passage 16 and the inlet passage 15. The overflow element 173 can be, but is not limited to, an overflow valve, a safety valve, or an electrically controlled valve. The function of the overflow element 173 is that, when the pressure in the high-pressure passage is greater than a preset value, the overflow element 173 is opened to release the urea solution in the high-pressure passage into the low-pressure passage or return it directly to the urea tank 201, thereby realizing pressure regulation.
In order to drive the urea pump 11, the urea pump 11 is provided with a motor coil 111 communicating with the controller 13. In order to drive the urea nozzle 12, the urea nozzle 12 is provided with a nozzle coil 121 communicating with the controller 13.
The controller 13 is in communication with the temperature sensor 171 and the pressure sensor 172 to transmit temperature signals and pressure signals to the controller 13. Certainly, in order to achieve precise control, the controller 13 can also receive other signals, such as signals from a CAN bus related to engine operating parameters. In addition, the controller 13 can also obtain the rotational speed of the urea pump 11; certainly, the acquisition of a 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, respectively. An advantage of this control is that it can reduce the influence of the operation of the urea pump 11 on the urea nozzle 12 to achieve high control accuracy.
In addition, in some cases, the urea nozzle 12 needs to be cooled because the engine exhaust has a high temperature and the urea nozzle 12 is installed on the exhaust pipe. The integrated device 1 is further provided with a cooling assembly for this purpose, and the cooling assembly cools the urea nozzle 12 with a cooling medium. The cooling medium can be, but is not limited to, air, and/or an engine coolant, and/or a lubricating oil, and/or urea, etc. As shown in FIG. 2, the illustrated embodiment of the present invention employs water cooling, that is, using an engine coolant, to cool the urea nozzle 12. In the housing 14, a cooling passage 141 is provided through which an engine coolant can pass.
As shown in FIG. 2, the integrated device 1 works as follows:
- The controller 13 drives the urea pump 11 to operate; the urea solution located in the urea tank 201 is sucked into the urea pump 11 through the inlet passage 15; after pressurization, the urea solution is transported to the urea nozzle 12 through the outlet passage 16, wherein the controller 13 collects and/or calculates signals needed, such as temperature, pressure, and pump speed. When an injection condition is reached, the controller 13 sends a control signal to the urea nozzle 12, such as electrifying the nozzle coil 121, and realizes urea injection by controlling the movement of the valve needle. 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 present invention, the controller 13 independently controls the urea pump 11 and the urea nozzle 12, respectively.
As shown in FIGS. 3 to 65, the integrated device 1 comprises a pump 18, a nozzle assembly 19, and a controller 13 in the illustrated embodiment of the present invention. As shown in FIG. 10, the nozzle assembly 19 is at least partially inserted into the pump assembly 18 and assembled together by a number of fastening bolts 64.
As shown in FIGS. 3 to 10, in the illustrated embodiment of the present invention, the pump assembly 18 comprises a pump assembly housing 180 and a urea pump 11 matching the pump assembly housing 180. The pump assembly housing 180 comprises an enclosure 2 located at the top and a first housing 3, a second housing 4 and a third housing 5 located below the enclosure 2 and stacked together. In the illustrated embodiment of the present invention, the first housing 3, the second housing 4, and the third housing 5 are all made of metal materials.
As shown in FIGS. 11 and 12, the enclosure 2 comprises an enclosure cavity 21 for covering the controller 13 and at least a part of the pump assembly 18, a through-hole 22 connected to the enclosure cavity 21, a plurality of first mounting holes 23 located in the periphery, and a waterproof and breathable cover 24 fixed in the through-hole 22. The controller 13 is equipped with a chip and other electronic components, which heat up when they work, causing the air around them to expand. The present invention solves the problem of damage to the chip and/or electronic components due to air expansion by providing a waterproof and breathable cover 24, which also has a waterproof effect. In addition, the waterproof and breathable cover 24 can improve the operating environment of the controller 13, allowing it to meet the working conditions. In the illustrated embodiment of the present invention, in order to improve the heat dissipation performance, the enclosure 2 is made of a metal material with a good heat dissipation effect. In addition, the enclosure 2 can also be provided with a plurality of external heat sinks (not shown) to enhance the heat dissipation effect.
As shown in FIGS. 11 and 14, the controller 13 comprises a control board 131 and a wiring plug 132 welded to the control board 131. The wiring plug 132 passes through the enclosure 2 to become exposed for connection to an external circuit. In the illustrated embodiment of the present invention, the control board 131 is annular and is provided with a central hole 135 located in the middle. The pump assembly 18 is also provided with a plurality of supporting columns 631 mounted on the first housing 3 to support the control board 131.
As shown in FIG. 11 and FIGS. 14 to 19, the pump assembly housing 180 is also provided with a connecting plate assembly 6 positioned between the enclosure 2 and the first housing 3. Specifically, the connecting plate assembly 6 is provided with a plate portion 61 and a metal cover 62 that is fixed on the plate portion 61 and projects upwards. The metal cover 62 passes upward through the central hole 135 of the control board 131. As shown in FIG. 11, the control board 131 is held together by the supporting columns 631 and the enclosure 2, and a gap is formed between the control board and the connecting plate assembly 6 to ensure better heat dissipation of the control board 131 and better interference avoidance.
As shown in FIG. 16, the plate portion 61 is provided with a through-hole 614, a first threading hole 618, and a perforation 615 running through its upper and lower surfaces. As shown in FIG. 14, the pressure sensor 172 at least partially passes through the through-hole 614, and the temperature sensor 171 at least partially passes through the perforation 615. The conductive wire 1721 of the pressure sensor 172 passes through the through-hole 614, the conductive wire 124 of the nozzle assembly 19 passes through the first threading hole 618, and the conductive wire 1711 of the temperature sensor 171 passes through the perforation 615 and is electrically connected to the control board 131. In addition, as shown in FIG. 15, the plate portion 61 is provided with a plurality of mounting holes 611 through which the screw 133 passes. As shown in FIG. 17, the plate portion 61 is provided with a hole 617 corresponding to the metal cover 62. In the illustrated embodiment of the present invention, the lower end of the metal cover 62 is welded on the inner wall of the hole 617.
In the illustrated embodiment of the present invention, the urea pump 11 is a gear pump, comprising a motor coil 111, the metal cover 62, an elastic body 71 and a magnetic body 72 located within the metal cover 62, a first sealing ring 73 located below the metal cover 62, and a first gear assembly 74 and a second gear assembly 75 meshing with each other. Since a gear pump can provide relatively high working pressure, it is conducive to increasing the flow rate of the urea nozzle 12. In addition, a gear pump can also be reversed, which is conducive to the pumping of residual urea solution and reduction of risks of urea crystallization. As shown in FIGS. 12 and 13, the motor coil 111 is provided with a bracket 112 and a coil 113 wound on the bracket 112. The bracket 112 is provided with a hole 114 for accommodating the metal cover 62. In the illustrated embodiment of the present invention, the motor coil 111 is interference-fitted within the enclosure cavity 21 so that the motor coil 111 can be integrated with the enclosure cavity 21 without the use of any additional fixing elements (such as screws), thereby reducing the number of parts. In addition, as shown in FIGS. 20 and 21, the urea pump 11 further comprises an outer sleeve 723 for accommodating the magnetic body 72, and the outer sleeve 723 is directly housed in the metal cover 62.
As shown in FIG. 59, the motor coil 111 is sleeved on the periphery of the metal cover 62. The plate portion 61 presses down the first sealing ring 73 to realize sealing. In the illustrated embodiment of the present invention, the elastic body 71 is located at the lower end of the magnetic body 72, and the elastic body 71 and the magnetic body 72 are supported together by a metal frame 720; for example, the magnetic body 72 and the elastic body 71 are respectively sleeved at the upper and lower ends of the metal frame 720. The metal frame 720 is provided with a partition plate 721 positioned between the elastic body 71 and the magnetic body 72. Except for the partition plate 721, the metal frame 720 is a hollow cylinder on the whole, and the first gear assembly 74 is at least partially accommodated in the metal frame 720 (as shown in FIG. 59). In order to better limit the elastic body 71, the end of the metal frame 720 is provided with a hook 724 which is pressed against the elastic body 71. The hook 724 is provided with a guide cone 725 which makes it easy to sleeve the elastic body 71 on the metal frame 720. The elastic body 71 is provided with a radially extending assembly hole 711, the metal frame 720 is provided with a fixing hole 726 corresponding to the assembly hole 711, and the upper end of the first gear assembly 74 is radially fixed with the metal frame 720 by a screw 722 installed in the assembly hole 711 and the fixing hole 726. This arrangement can prevent the axial movement of the first gear assembly 74 and improve the running stability of the gear pump. It is well known that when a urea solution is frozen, its volume expands. In the present invention, an elastic body 71 is provided. The elastic body 71 can be compressed to absorb the volume expansion, thereby avoiding damage to any other component due to volume expansion.
As shown in FIGS. 22 to 25, in the illustrated embodiment of the present invention, the pressure sensor 172 comprises a base plate 176, a circuit board 177 fixed to the base plate 176, a conductive wire 1721 connected to the circuit board 177, and a protective cover 178 fastened to the circuit board 177. The base plate 176 is provided with a plate body 1761 and a convex portion 1762 that extends downward from the plate body 1761, and a sealing ring 1722 is arranged on the convex portion 1762. The convex portion 1762 is provided with a through-hole 1763 that penetrates downward, and the through-hole 1763 penetrates the plate portion 1761 and the circuit board 177 upwards. The circuit board 177 is provided with a chip 1771 in the position corresponding to the through-hole 1763. The protective cover 178 is mounted on the periphery of the chip 1771 to protect the chip 1771. In the illustrated embodiment of the present invention, the cover 178 is cuboid, and the cover 178 is provided with a hole 1781 in communication with the chip 1771. As shown in FIGS. 25 and 59, unlike a pressure sensor in the prior art, the pressure sensor 172 in the present invention does not have an independent housing; instead, it uses the enclosure 2 as its housing. This arrangement can reduce the volume, facilitate installation, and reduce costs. In the illustrated embodiment of the present invention, the pressure sensor 172 is a differential pressure sensor that converts differential pressure changes at the upper and lower ends of the chip 1771 into electrical signals. Since the working principle of differential pressure sensors is well known to those of ordinary skill in the art, it will not be detailed again here.
As shown in FIGS. 26 to 48, in the illustrated embodiment of the present invention, the first housing 3, the second housing 4, and the third housing 5 are machined workpieces and are fixed together from top to bottom by bolts 66. The first housing 3 comprises 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 a first island portion 312 surrounded by the first annular groove 311. The first annular groove 311 is used for accommodating the first sealing ring 73. 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 used for accommodating the second sealing ring 731 (as shown in FIG. 64).
The first island portion 312 is provided with a first positioning hole 3121 that penetrates the first upper surface 31 and the first lower surface 32, a second positioning hole 3122 that penetrates the first lower surface 32, a first connecting hole 3123 that penetrates the first upper surface 31 and is in communication with the inlet passage 15, and a first diversion groove 3124 that penetrates the first upper surface 31 and is in communication with the second positioning hole 3122. As shown in FIGS. 27, 28, and 59, the urea pump 11 is provided with a first shaft sleeve 76 accommodated in the first positioning hole 3121 and a second shaft sleeve 77 accommodated in the second positioning hole 3122. In addition, the first housing 3 further comprises an inner threaded hole 317 corresponding to the screw 133. During assembly, the screw 133 is tightened in the inner threaded hole 317 after passing through the mounting hole 611 of the plate portion 61 to fix the connecting plate assembly 6. The first housing 3 further comprises a plurality of first assembling holes 318 for the bolts 66 to pass through. The first assembling holes 318 pass through the first upper surface 31 and the first lower surface 32. The first upper surface 31 is also provided with a pressure sensor accommodation hole 313 located on a side of the first island portion 312 for accommodating the pressure sensor 172 and a temperature sensor accommodation hole 314 for accommodating the temperature sensor 171. As shown in FIG. 59, the sealing ring 1722 on the pressure sensor 172 is sealed with the inner wall of the pressure sensor accommodation hole 313. The pressure sensor 172 is pressed by the plate portion 61 to achieve fixation. In addition, the first housing 3 is also provided with an outwardly convex mounting flange 315, and the mounting flange 315 is provided with a second mounting hole 316 corresponding to the first mounting hole 23. During assembly, the bolts 63 successively pass through the second mounting hole 316 and the supporting columns 631, and are fastened in the internal thread of the first mounting hole 23. With this arrangement, the first housing 3 and the enclosure 2 can be fixed, and the control board 131 can be clamped (see FIG. 59).
In addition, as shown in FIG. 30, the first housing 3 is provided with a liquid inlet passage 332 that runs through the first side surface 33 for connection with a urea connector 331. The first housing 3 is provided with a second connecting hole 3127 that penetrates the first lower surface 32 and is in communication with the liquid inlet passage 332. The first connecting hole 3123 and the second connecting hole 3127 are perpendicular to the liquid inlet passage 332. The first positioning hole 3121, the second positioning hole 3122 and the second connecting hole 3127 penetrate the second island portion 326 downward. The second island portion 326 is also provided with an outlet hole 3126 that penetrates the first lower surface 32. The first lower surface 32 is provided with a first relief groove 321 in communication 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 also provided with an accommodation compartment 322 that penetrates down the first lower surface 32 to accommodate at least a part of the nozzle assembly 19. As shown in FIGS. 33, 34 and 36, the accommodation compartment 322 is in communication with the pressure sensor accommodation hole 313. The accommodation compartment 322 is also in communication with the outlet hole 3126. As shown in FIGS. 32 and 33, in the illustrated embodiment of the present invention, the outlet hole 3126 is inclined and roughly in the shape of an inverted “V” within the first housing 3. The first housing 3 is provided with a second threading hole 323 corresponding to the first threading hole 618.
In addition, as shown in FIGS. 38, 64, and 65, the first housing 3 is also provided with an overflow element accommodation groove 319 in communication with the inlet passage 332 and the accommodation compartment 322. The overflow element accommodation groove 319 penetrates outwardly through the first side surface 33 to accommodate the overflow element 173. The overflow element 173 is a relief valve in the illustrated embodiment of the present invention, and its objective is to ensure that the pressure in the high-pressure passage of 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. As shown in FIG. 65, the overflow element 173 is provided with a trickle hole 1731 that is always in communication with the inlet passage 15 and the outlet passage 16. With this arrangement, on the one hand, the pressure fluctuation of the system can be reduced, especially when the nozzle assembly 19 is injecting urea; on the other hand, the urea solution can be kept flowing, which is conducive to the heat dissipation of the motor coil 111.
As shown in FIG. 1, the urea connector 331 is in communication with the urea tank 201 through the urea connecting pipe 333. In order to better realize the pyrolysis function, the exhaust-gas aftertreatment system 100 can also be provided with a heating device 334 for heating the urea connecting pipe 333. As shown in FIGS. 22 and 29, in the illustrated embodiment of the present invention, the liquid inlet passage 332 extends horizontally into the first housing 3. Certainly, in other embodiments, the liquid inlet passage 332 can also be arranged at a certain angle.
As shown in FIGS. 39 to 41, the first gear assembly 74 comprises a first gear shaft 741 and a first gear 742 fixed on the first gear shaft 741; the second gear assembly 75 comprises a second gear shaft 751 and a second gear 752 fixed on the second gear shaft 751, and the first gear 742 meshes with the second gear 752. As shown in FIG. 34, in the illustrated embodiment of the present invention, the first gear 742 meshes with the second gear 752 externally. In addition, the first gear shaft 741 is a driving 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 shaft sleeve 76 and is at least partially fixed in the metal frame 720. The upper end of the second gear shaft 751 is positioned in the second shaft sleeve 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.
The second housing 4 is positioned below the first housing 3 and connected with the first housing 3. In addition, a plurality of positioning pins 328 are arranged between the first housing 3 and the second housing 4 for better positioning. The second housing 4 comprises a second upper surface 41, a second lower surface 42, and a gear groove 43 that runs through the second upper surface 41 and the second lower surface 42 for accommodating the first gear 742 and the second gear 752. One side of the gear groove 43 is provided with a liquid inlet cavity 431 in communication with the inlet passage 15, and the other side of the gear groove 43 is provided with a liquid outlet cavity 432 in communication with the outlet passage 16. Specifically, the liquid inlet cavity 431 is in communication with the second connecting hole 3127, and the upper end of the liquid outlet cavity 432 is in communication with the outlet hole 3126. In addition, the second upper surface 41 of the second housing 4 is provided with a first accommodating hole 411 through which the nozzle assembly 19 passes, and the second lower surface 42 is provided with a second accommodating hole 421 for positioning the nozzle assembly 19. The second accommodating hole 421 is larger than the first accommodating hole 411 so as to form stepped holes. The nozzle assembly 19 protrudes upwards from the second upper surface 41 and is accommodated in the accommodation compartment 322. With is arrangement, a high-pressure urea solution can be delivered to the urea nozzle 12. In addition, the second upper surface 41 is also provided with a third threading hole 412 corresponding to the second threading hole 323. The first threading hole 618, the second threading hole 323, and the third threading hole 412 are aligned to each other for the passage of the conductive wire 124 of the nozzle assembly 19. The second housing 4 further comprises a plurality of second assembling holes 418 aligned with the first assembling holes 318.
As shown in FIGS. 26, and 45 to 48, the third housing 5 is located below the second housing 4 and connected to the second housing 4. The third housing 5 comprises a body portion 51, a convex portion 52 extending downward from the body portion 51, and a flange 53 extending outward from the body portion 51. The flange 53 is provided with a plurality of third assembling holes 531 aligned with the second assembling holes 418 for the bolts 66 to pass through. The body portion 51 is provided with a third upper surface 511; 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 used to accommodate a third sealing ring 732 (as shown in FIG. 64). The third island portion 513 is provided with a third positioning hole 5111 that penetrates the third upper surface 511 and a fourth positioning hole 5112 that penetrates the third upper surface 511. The third housing 5 is provided with a third shaft sleeve 78 which is housed in the third positioning hole 5111 and a fourth shaft sleeve 79 which is housed in the fourth positioning hole 5112. The lower end of the first gear shaft 741 is positioned in the third shaft sleeve 78, and the lower end of the second gear shaft 751 is positioned in the fourth shaft sleeve 79.
In addition, the third island portion 513 is provided with a second diversion groove 5114 and a third diversion groove 5115 arranged on the third upper surface 511, wherein the second diversion groove 5114 is in communication with the third positioning hole 5111, and the third diversion groove 5115 is in communication with the fourth positioning hole 5112. As shown in FIG. 43, the second diversion groove 5114 and the third diversion groove 5115 are inclined inside the third housing 5. As shown in FIG. 48, the lower end of the liquid outlet cavity 432 is in communication with the second diversion groove 5114 and the third diversion groove 5115.
During operation, a urea solution enters the liquid inlet passage 332 through the urea connecting pipe 333; one part of the urea solution enters the metal cover 62 through the first connecting hole 3123, and the other part of the urea solution enters the liquid inlet cavity 431 through the second connecting hole 3127. The urea solution located in the metal cover 62 seeps directly into the first positioning hole 3121 to lubricate the first shaft sleeve 76 and the second positioning hole 3122 along the first diversion groove 3124 to lubricate the second shaft sleeve 77. The urea solution entering the liquid inlet cavity 431 is divided into two branches. One branch enters the outlet passage 16 after being pressurized by the gear pump. The other branch enters the third positioning hole 5111 and the fourth positioning hole 5112 respectively through the second diversion groove 5114 and the third diversion groove 5115 to lubricate the third shaft sleeve 78 and the fourth shaft sleeve 79, so as to improve the rotational stability of the gear pump and reduce its wear. The high-pressure urea solution entering the outlet passage 16 enters the accommodation compartment 322 along the outlet hole 3126 to flow to the nozzle assembly 19, while a part of the urea solution flows to the overflow element 173. When the pressure is smaller than a preset value of the overflow element 173, the overflow element 173 is closed and is in communication only through the trickle hole 1731; when the pressure is greater than the preset value of the overflow element 173, the overflow element 173 opens, and a part of the urea solution enters the liquid inlet passage 332 to achieve pressure relief.
It is understandable that in the illustrated embodiment of the present invention, the inlet passage 15 comprises the liquid inlet passage 332, the second connecting hole 3127, and the liquid inlet cavity 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 comprises the liquid outlet cavity 432, the outlet hole 3126, the accommodation compartment 322, etc. Since the outlet passage 16 is located downstream of the urea pump 11, it is called a high-pressure passage.
As shown in FIGS. 49 to 58, the nozzle assembly 19 comprises a nozzle assembly housing 190 and a urea nozzle 12 matching the nozzle assembly housing 190.
The nozzle assembly housing 190 comprises a main body portion 91, an extension portion 92 extending downward from the main body portion 91, and a mounting flange 93 extending outward from the main body portion 91. The mounting flange 93 is provided with a plurality of mounting holes 931 for mounting the integrated device 1 to the exhaust pipe 106 or the housing 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 an accommodation compartment 94 for accommodating the urea nozzle 12 and a groove 95 for accommodating the convex portion 52. As shown in FIG. 55, the accommodation compartment 94 extends downward into the extension portion 92. The main body portion 91 is also provided with a cylindrical portion 917 that protrudes upward into the accommodation compartment 94 to support the urea nozzle 12.
The nozzle assembly housing 190 is also provided with the cooling assembly for cooling the urea nozzle 12. In the illustrated embodiment of the present invention, the cooling assembly is a water-cooling assembly. The cooling passage 141 located in the nozzle assembly housing 190 comprises a first cooling passage 913 running through the fourth side surface 912 and a second cooling passage 914 spaced with the first cooling passage 913, wherein the first cooling passage 913 is connected with the inlet connector 103, and the second cooling passage 914 is connected with the outlet connector 104. The nozzle assembly housing 190 is provided with an end cover 96 sealed at the periphery of the extension portion 92. In the illustrated embodiment of the present invention, the end cover 96 is welded on the extension portion 92. With this arrangement, the nozzle assembly housing 190 forms an annular cooling groove 916 that connects the first cooling passage 914 and the second cooling passage 915 between the end cover 96 and the extension portion 92.
In the illustrated embodiment of the present invention, the mounting flange 93 is machined integrally with the main body portion 91. Certainly, in other embodiments, the mounting flange 93 can also be made separately from the main body portion 91 and then they are welded together.
As shown in FIG. 50, in the illustrated embodiment of the present invention, the urea nozzle 12 comprises a nozzle coil 121, a magnetic portion 81 interacting with the nozzle coil 121, a valve needle portion 82 arranged below the magnetic portion 81, a spring 83 acting between the magnetic portion 81 and the valve needle portion 82, and a valve seat 84 matching the valve needle portion 82 (see FIG. 5). The nozzle coil 121 is wound around the periphery of the magnetic portion 81. The urea nozzle 12 further comprises a sleeve portion 122 which is sleeved on the periphery of the nozzle coil 121. The spring 83 is installed in the magnetic portion 81 and the valve needle portion 82. The valve needle portion 82 is provided with a conical portion 821 and a valve needle 822 extending downwards from the conical portion 821. As shown in FIG. 52, the valve seat 84 comprises a swirling sheet 85 welded on the extension portion 92. The swirling sheet 85 is provided with an injection hole 851 matching the valve needle 822 and a plurality of swirling grooves 852 in communication with the injection hole 851. As shown in FIGS. 10, 50 and 59, the upper end of the magnetic portion 81 is sleeved with a fourth sealing ring 812 to seal the inner wall of the accommodation compartment 322; the lower end of the magnetic portion 81 is sleeved with a fifth sealing ring 813 to seal the inner wall of the accommodation compartment 94. As shown in FIG. 59, the cylindrical portion 917 supports the valve needle portion 82 so that the valve needle portion 82 and the nozzle coil 121 can overlap substantially in the moving direction of the valve needle 822 and increase the influence of the electromagnetic force generated by the nozzle coil 121 on the valve needle portion 82, thereby reducing the driving current, reducing the power consumption of the urea nozzle 12, and reducing the heat generation. In addition, a gasket 86 matching the urea nozzle 12 to adjust the gap between the magnetic portion 81 and the valve needle portion 82 is provided in the accommodation compartment 94. Understandably, the stroke of the valve needle portion 82 is closely related to the above-mentioned gap. By adjusting the gap with gaskets 86 having different thicknesses, the stroke of valve needle portion 82 can be accurately controlled to improve the accuracy of the urea nozzle 12.
As shown in FIG. 59, the extension portion 92 is provided with a current collection cavity 921, and the valve needle 822 extends into the current collection cavity 921. The magnetic portion 81 is provided with a first communicating hole 811 in communication with the accommodation compartment 322, the valve needle portion 82 is provided with a second communicating hole 823 in communication with the first communicating hole 811, and the conical portion 821 is provided with a third communicating hole 824 that allows the second communicating hole 823 to be in communication with the current collection cavity 921. The swirling groove 852 is in communication with the current collection cavity 921. The lower part of the sleeve portion 122 is accommodated in the accommodation compartment 94, and the part of the sleeve portion 122 that protrudes from the fourth upper surface 911 is accommodated in the accommodation compartment 322. The annular cooling groove 916 is located at the periphery of the current collection cavity 921.
It is understandable that in other embodiments of the present invention, for example, an integrated device is applied to injecting a fuel into the exhaust of an engine to achieve regeneration of a downstream diesel particulate filter (DPF). In this application, the urea pump 11 can be replaced by a fuel pump, the urea nozzle 12 can be replaced by a fuel nozzle, and the urea solution can be replaced by a fuel. This variation is readily apparent to those of ordinary skill in the art and therefore is not detailed again herein.
For a better understanding of the present invention, the urea pump and the fuel pump are collectively called the pump, the urea nozzle and the fuel nozzle are collectively called the nozzle, and the urea solution and the fuel are collectively called the fluid medium.
Compared with the prior art, the integrated device 1 of the present invention is an integrated design, which can omit or shorten a urea pipe used in the prior art to connect a pump with a nozzle, or omit the plug-ins between various sensors and wire harness in a pump supply unit of the prior art, or require no pyrolyzer, and therefore is highly reliable. The integrated device 1 of the present invention has a compact structure and a small volume, and is convenient for installation in various types of vehicles. In addition, in the integrated device 1 of the present invention, the inner fluid medium passage is short, the pressure drop is small, and the dead volume between the pump and the nozzle is small; therefore, the efficiency is high. The temperature sensor 171 and the pressure sensor 172 are near the nozzle, and the injection pressure precision is high. In addition, through separate control of the pump and the nozzle, nozzle movement driven by pump actions is avoided, and thus the control accuracy is improved. Because of the improved injection accuracy of the nozzle, the amount of urea injected into and out of the exhaust gas can be made proportional to the amount of nitrogen oxides; thus, the crystallization risk caused by excessive injection of urea is reduced. The integrated device 1 of the present invention can adopt water cooling so that the urea residue in the integrated device 1 cannot reach the crystallization point and no crystallization is produced.
While the present invention has been particularly described above with reference to preferred embodiments, it should be understood that said embodiments are not intended to limit the present invention and that those of ordinary skill in the art can make various modifications, equivalent substitutions, and improvements without departing from spirit and scope of the present invention as defined by the Claims.
Patent Application
20190292962
