INTEGRATED APPARATUS, EXHAUST GAS POST-PROCESSING SYSTEM, AND CONTROL METHOD

Abstract

An integrated apparatus of a pump and a nozzle, comprising a pump component and a nozzle component. The pump component comprises a motor housing assembly, a magnetic cover component and a pump housing assembly. The motor housing assembly comprises a magnetic screening cover and a motor coil. The motor housing assembly is fixed to the pump housing assembly by means of a method of rolling or welding. The pump housing assembly comprises an inlet pathway, which is in communication with a pump, and an outlet pathway, the outlet pathway being in communication with the nozzle component. The pump housing assembly also comprises a first gear assembly and a second gear assembly which are mutually engaged. The nozzle component comprises a nozzle assembly and a water cooling base, wherein the nozzle assembly comprises a nozzle coil for use in driving the nozzle. The integrated apparatus has a simple and compact structure, and high precision control. In addition, also provided is an exhaust gas post treatment system and a control method.

Description

This application claims the priority of Chinese patent application no. 201710042454.9 with invention title “Integrated apparatus, exhaust gas post-processing system, and control method”, filed on Jan. 20, 2017, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an integrated apparatus, an exhaust gas post-processing system and a control method, in the technical field of engine exhaust gas post-processing.

BACKGROUND ART

As emissions standards for internal combustion engine vehicles become ever more stringent, selective catalytic reduction (SCR) is generally used as a post-processing technology in the industry at present, with the injection of a urea solution into exhaust gas being installed upstream of the SCR, in order to reduce the amount of harmful substances such as nitrogen oxides in exhaust gas. The urea solution undergoes hydrolysis and pyrolysis to generate ammonia, which undergoes a chemical reaction with nitrogen oxides, etc., thereby reducing the concentration of harmful substances.

At present, urea injection systems on the market generally comprise air assistance systems and non-air assistance systems. Of course, regardless of the type of system, they all comprise a urea tank assembly, a pump supply unit connected to the urea tank assembly via a low-pressure pipeline, a nozzle module connected to the pump supply unit via a high-pressure pipeline, and a controller. The pump supply unit comprises a urea pump and a pressure sensor, etc.; the nozzle module comprises a urea nozzle, etc. The urea pump and the urea nozzle are separated by a large distance, and connected to each other via a urea pipe. In addition, existing urea injection systems contain a large number of components, are complex to install and have a high cost.

For these reasons, there is an urgent need to provide a novel technical solution.

CONTENT OF THE INVENTION

An object of the present invention is to provide an integrated apparatus with relatively precise control, an exhaust gas post-processing system and a control method.

To achieve the abovementioned object, the present invention employs the following technical solution:

An integrated apparatus of a pump and a nozzle, wherein the pump is used for pumping a fluid medium toward the nozzle, and the nozzle is used for injecting the fluid medium into intake gas or exhaust gas of an engine; the integrated apparatus comprises a pump component and a nozzle component; the pump component comprises an electric machine casing assembly, a magnetic cover component at least partially located in the electric machine casing assembly, and a pump housing assembly cooperating with the electric machine casing assembly; the electric machine casing assembly comprises an electromagnetic shielding cover, and an electric machine coil at least partially located in the electromagnetic shielding cover; the magnetic cover component comprises a metal cover at least partially inserted into the electric machine coil, and a rotor received in the metal cover; the electric machine casing assembly and the pump housing assembly are fixed together by roll extrusion or welding; the pump housing assembly 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, wherein the outlet passage is in communication with the nozzle component; the pump housing assembly further comprises a first gear component and a second gear component meshed with each other, wherein the first gear component comprises a first gear shaft and a first gear, the second gear component comprises a second gear shaft and a second gear, the first gear and the second gear being meshed with each other, and the rotor being fixed to the first gear shaft; the nozzle component comprises a nozzle assembly, and a water-cooled base connected in a surrounding manner at the outside of the nozzle assembly, wherein the nozzle assembly comprises a nozzle coil for driving the nozzle.

In a further 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.

In a further 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.

In a further improved technical solution of the present invention, the controller subjects the urea pump and the urea nozzle respectively to independent control; the electric machine casing assembly comprises a controller, the controller comprising a circuit board, with the electric machine coil and the nozzle coil both being connected to the circuit board.

In a further improved technical solution of the present invention, the integrated apparatus comprises a sensor, in communication with the outlet passage in order to detect temperature and pressure, and an overflow element connected between the outlet passage and the inlet passage.

In a further improved technical solution of the present invention, the first gear shaft is a driving shaft, the second gear shaft is a driven shaft, and the first gear shaft is higher than the second gear shaft.

In a further improved technical solution of the present invention, a freeze-resistant body located above the rotor is further provided in the metal cover, the freeze-resistant body being compressible in order to absorb an expansion volume caused by the freezing of urea.

In a further improved technical solution of the present invention, the pump component further comprises an elastic body received in the metal cover and located below the rotor, the elastic body being compressible in order to absorb an expansion volume caused by the freezing of urea.

In a further improved technical solution of the present invention, the pump housing assembly is provided with a gear slot receiving the first gear and the second gear, the first gear and the second gear are meshed externally, one side of the gear slot is provided with a liquid entry cavity in communication with the inlet passage, and another side of the gear slot is provided with a liquid exit cavity in communication with the outlet passage.

In a further improved technical solution of the present invention, the pump housing assembly is further provided with a first freeze-resistant rod located in the liquid entry cavity and a second freeze-resistant rod located in the liquid exit cavity; the first freeze-resistant rod and the second freeze-resistant rod are both compressible when urea freezes.

In a further improved technical solution of the present invention, the nozzle assembly comprises a magnetic part interacting with the nozzle coil, a first sleeve at least partially receiving the magnetic part, a valve needle part located below the magnetic part, a second sleeve at least partially receiving the valve needle part, a spring acting between the magnetic part and the valve needle part, a valve seat cooperating with the valve needle part, and a rotational flow plate which is manufactured separately from the valve seat and is in close abutment with the valve seat; the rotational flow plate is provided with a number of rotational flow grooves.

In a further improved technical solution of the present invention, the nozzle coil is located at the periphery of the magnetic part, the valve needle part is provided with a valve needle, the first sleeve and the second sleeve are fixed together to form a space around the periphery of the valve needle part, the valve needle is provided with a through-hole in communication with the space, the second sleeve is provided with a communication groove establishing communication between the space and the rotational flow grooves, and the valve seat is provided with an injection hole cooperating with the valve needle.

In a further improved technical solution of the present invention, the electric machine casing assembly is provided with an injection-molded connection insertion member electrically connected to the circuit board, a number of electronic components are mounted on the circuit board, and the electric machine casing assembly further comprises a heat dissipating pad covering a surface of the electronic components.

In a further improved technical solution of the present invention, the magnetic cover component comprises a sheet part located below the metal cover, the sheet part being fixed to the pump housing assembly by means of a number of screws.

In a further improved technical solution of the present invention, the pump housing assembly comprises a first housing, the first housing comprising a first upper surface, a first lower surface and a first side, wherein the first upper surface is provided with a first annular groove, a first island surrounded by the first annular groove, and a first sealing ring received in the first annular groove, with the sheet part pressing down on the first sealing ring; the first island is provided with a first positioning hole running through the first lower surface, and a second positioning hole running through the first lower surface; the urea pump comprises a first shaft sleeve received in the first positioning hole, and a second shaft sleeve received 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.

In a further improved technical solution of the present invention, the first lower surface is provided with a first load release groove establishing communication between the first positioning hole and the second positioning hole.

In a further improved technical solution of the present invention, the first island further comprises a first flow-guiding groove running through the first upper surface and in communication with the second positioning hole, and a first outlet hole running through the first upper surface and in communication with the liquid exit cavity; the first upper surface is further provided with a sensor receiving hole, located at a side of the first island and used for receiving a sensor, and the integrated apparatus comprises the sensor for detecting temperature and pressure; the first housing is further provided with a second outlet hole in communication with the sensor receiving hole.

In a further improved technical solution of the present invention, the first housing is provided with an overflow element receiving slot, and the integrated apparatus is provided with an overflow element mounted in the overflow element receiving slot; when a pressure of the outlet passage is higher than a set value, the overflow element opens in order to return a portion of the urea solution into the inlet passage.

In a further improved technical solution of the present invention, the pump housing assembly comprises a second housing, located below the first housing and connected to the first housing; the second housing comprises a second upper surface and a second lower surface, with the gear slot running through the second upper surface and the second lower surface.

In a further improved technical solution of the present invention, the pump housing assembly comprises a third housing, located below the second housing and connected to the second housing; the third housing comprises a body part, and a protruding part extending downward from the body part, wherein the body part is provided with a third upper surface, with the third upper surface being provided with a third annular groove and a third island surrounded by the third annular groove; the third island is provided with a third positioning hole and a fourth positioning hole running through the third upper surface, the third positioning hole and the fourth positioning hole extending into the protruding part; the urea pump comprises a third shaft sleeve received in the third positioning hole, and a fourth shaft sleeve received 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.

In a further improved technical solution of the present invention, the third island is provided with a second flow-guiding groove and a third flow-guiding groove running through the third upper surface, wherein the second flow-guiding groove is in communication with the third positioning hole, and the third flow-guiding groove is in communication with the fourth positioning hole.

In a further improved technical solution of the present invention, the nozzle assembly comprises a magnetic part interacting with the nozzle coil, a valve needle part located below the magnetic part, a spring acting between the magnetic part and the valve needle part, and a valve seat cooperating with the valve needle part.

In a further improved technical solution of the present invention, the nozzle assembly further comprises a first sleeve at least partially receiving the magnetic part, and a second sleeve at least partially receiving the valve needle part; the spring is mounted in the magnetic part and the valve needle part; the valve needle part is provided with a tapered part, and a valve needle extending downward from the tapered part; the first sleeve and the second sleeve are fixed together to form a space around the periphery of the valve needle part, and the valve needle is provided with a through-hole in communication with the space.

In a further improved technical solution of the present invention, the nozzle assembly further comprises a rotational flow plate, manufactured separately from the valve seat and in close abutment with the valve seat, the rotational flow plate being provided with a number of rotational flow grooves; the second sleeve is provided with a communication groove establishing communication between the space and the rotational flow grooves, and the valve seat is provided with an injection hole cooperating with the valve needle.

In a further improved technical solution of the present invention, 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 the periphery of the mounting slot; between the end cap and the second sleeve, the nozzle assembly forms an annular cooling groove establishing communication between the first cooling passage and the second cooling passage; the first cooling passage is connected to an inlet connector to allow the injection of an engine coolant, and the second cooling passage is connected to an outlet connector to allow the engine coolant to flow out.

Also disclosed in the present invention is the following technical solution:

An exhaust gas post-processing system, comprising an injection system of exhaust gas post-processing and an encapsulated system of exhaust gas post-processing, wherein the injection system comprises the integrated apparatus described above, and the encapsulated system comprises a support located downstream of the integrated apparatus.

In a further improved technical solution of the present invention, the support comprises selective catalytic reduction, and the encapsulated system further comprises at least one mixer located between the integrated apparatus and the support.

Also disclosed in the present invention is the following technical solution:

A control method for an integrated apparatus, the integrated apparatus being the integrated apparatus described above, the control method comprising:

driving the rotor to operate, thereby driving the pump to operate, and drawing the fluid medium into the pump through the inlet passage;

after pressurization by the pump, delivering the fluid medium to the nozzle through the outlet passage;

when an injection condition is attained, energizing the nozzle coil, and at least partially opening the nozzle in order to inject the fluid medium into intake gas or exhaust gas of the engine, wherein:

the electric machine coil and the nozzle coil are respectively subjected to independent control.

Compared with the prior art, the integrated apparatus of the pump and the nozzle according to the present invention integrates the pump and the nozzle effectively, with a simple and compact structure, greatly facilitating installation by a customer. Furthermore, by controlling the electric machine coil and the nozzle coil, interference between the pump and nozzle is avoided, so the precision of control is improved. Based on the integration of the urea pump and the urea nozzle in the integrated apparatus, due to the improvement in control precision, a suitable ratio can be attained between the amount of urea injected into exhaust gas, and nitrogen oxides, reducing the risk of crystallization caused by excessive injection of urea.

DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 is a schematic diagram of the exhaust gas post-processing system of the present invention when used for the processing of engine exhaust gas.

FIG. 2 is a schematic diagram of the integrated apparatus in FIG. 1.

FIG. 3 is a three-dimensional schematic view of the integrated apparatus of the present invention in an embodiment.

FIG. 4 is a three-dimensional schematic view of FIG. 3 from another angle.

FIG. 5 is a three-dimensional schematic view of FIG. 3 from another angle.

FIG. 6 is a main view of FIG. 3.

FIG. 7 is a right view of FIG. 3.

FIG. 8 is a bottom view of FIG. 5.

FIG. 9 is a top view of FIG. 5.

FIG. 10 is a partial three-dimensional exploded view of the integrated apparatus of the present invention, wherein the pump component and the nozzle component have been separated.

FIG. 11 is a partial three-dimensional exploded view of the integrated apparatus of the present invention, wherein the electric machine casing assembly has been isolated.

FIG. 12 is a three-dimensional schematic view of the electric machine casing assembly in FIG. 11.

FIG. 13 is a three-dimensional schematic view of FIG. 12 from another angle.

FIG. 14 is a partial three-dimensional exploded view of FIG. 12.

FIG. 15 is a three-dimensional exploded view of FIG. 14 from another angle.

FIG. 16 is a further three-dimensional exploded view of FIG. 14, wherein the electric machine coil has been isolated.

FIG. 17 is a further three-dimensional exploded view of FIG. 16, wherein the electromagnetic shielding cover has been isolated.

FIG. 18 is a three-dimensional schematic view of the circuit board in FIG. 14 from another angle.

FIG. 19 is a further three-dimensional exploded view of FIG. 11.

FIG. 20 is a three-dimensional schematic view of the metal cover in FIG. 19 from another angle.

FIG. 21 is a three-dimensional exploded view of FIG.

20.

FIG. 22 is a further three-dimensional exploded view of FIG. 19.

FIG. 23 is a further three-dimensional exploded view of FIG. 22.

FIG. 24 is a further three-dimensional exploded view of FIG. 23, wherein the pump housing assembly, the nozzle assembly and the end cap, etc. have been isolated.

FIG. 25 is a three-dimensional view of the pump housing assembly in FIG. 24.

FIG. 26 is a partial three-dimensional exploded view of FIG. 25.

FIG. 27 is a three-dimensional exploded view of the first housing and elements thereon in FIG. 26.

FIG. 28 is a three-dimensional exploded view of FIG. 27 from another angle.

FIG. 29 is a three-dimensional view of the first housing in FIG. 27.

FIG. 30 is a three-dimensional view of FIG. 29 from another angle.

FIG. 31 is a top view of FIG. 30.

FIG. 32 is a top view of FIG. 29.

FIG. 33 is a sectional schematic view along line C-C in FIG. 32.

FIG. 34 is a sectional schematic view along line D-D in FIG. 32.

FIG. 35 is a sectional schematic view along line E-E in FIG. 32.

FIG. 36 is a sectional schematic view along line F-F in FIG. 32.

FIG. 37 is a three-dimensional schematic view after removing the first housing in FIG. 26.

FIG. 38 is a partial three-dimensional exploded view of FIG. 37.

FIG. 39 is a top view of FIG. 37.

FIG. 40 is a further three-dimensional exploded view of FIG. 38.

FIG. 41 is a three-dimensional view of the second housing in FIG. 40.

FIG. 42 is a top view of FIG. 41.

FIG. 43 is a three-dimensional view of the third housing in FIG. 40.

FIG. 44 is a top view of FIG. 43.

FIG. 45 is a sectional schematic view along line G-G in FIG. 44.

FIG. 46 is a sectional schematic view along line H-H in FIG. 44.

FIG. 47 is a three-dimensional view of the nozzle assembly in FIG. 24.

FIG. 48 is a top view of FIG. 47.

FIG. 49 is a sectional schematic view along line I-I in FIG. 48.

FIG. 50 is a three-dimensional exploded view of FIG. 47.

FIG. 51 is a further three-dimensional exploded view of FIG. 50.

FIG. 52 is a three-dimensional view of the water-cooled base in FIG. 24.

FIG. 53 is a three-dimensional view of FIG. 52 from another angle.

FIG. 54 is a sectional schematic view along line A-A in FIG. 9.

FIG. 55 is a sectional schematic view along line B-B in FIG. 9.

FIG. 56 is a sectional schematic view along line J-J in FIG. 54.

FIG. 57 is a sectional schematic view along line K-K in FIG. 54.

FIG. 58 is a sectional schematic view along line L-L in FIG. 54.

FIG. 59 is a sectional schematic view along line M-M in FIG. 54.

FIG. 60 is a sectional schematic view along line N-N in FIG. 54.

FIG. 61 is a sectional schematic view along line O-O in FIG. 58.

FIG. 62 is a sectional schematic view along line P-P in FIG. 59.

FIG. 63 is a sectional schematic view along line Q-Q in FIG. 62.

FIG. 64 is a three-dimensional exploded view of the integrated apparatus of the present invention.

PARTICULAR EMBODIMENTS

Referring to FIG. 1, the present invention discloses an exhaust gas post-processing system 100, which can be used to process exhaust gas of an engine 10, reducing emissions of harmful substances so as to meet the requirements of emissions regulations. The exhaust gas post-processing system 100 comprises an injection system 200 of exhaust gas post-processing and an encapsulated system 300 of exhaust gas post-processing, wherein the injection system 200 comprises an integrated apparatus 1 for pumping a urea solution from a urea tank 201 (see arrow X) and injecting the urea solution into intake gas or exhaust gas of the engine 10 (e.g. into an exhaust pipe 106 or the encapsulated system 300); the encapsulated system 300 comprises a mixer 301 located downstream of the integrated apparatus 1 and a support 302 located downstream of the mixer 301. Of course, in some embodiments, it is also possible for no mixer to be provided, or for two or more mixers to be provided. The support 302 may for example be selective catalytic reduction (SCR), etc.

The engine 10 has an engine coolant circulation loop. Referring to FIG. 1, in an embodiment shown in the figures of the present invention, the engine coolant circulation loop comprises a first circulation loop 101 (see the thick arrow Y) and a second circulation loop 102 (see the thin arrow Z), wherein the first circulation loop 101 is used for cooling the integrated apparatus 1, to reduce the risk of the latter being damaged by the heat of high-temperature engine exhaust gas; the second circulation loop 102 is used for heating the urea tank 201, to realize a heating and thawing function. It can be understood that in the first circulation loop 101, the integrated apparatus 1 is provided with an inlet connector 103 allowing an engine coolant to flow in, and an outlet connector 104 allowing the engine coolant to flow out; in the second circulation loop 102, it is provided with a control valve 105, to open or close the control valve 105 under appropriate conditions, realizing control of the second circulation loop 102. A heating rod 202 connected in the second circulation loop 102 is provided in the urea tank 201, to heat and thaw the urea solution using the temperature of the engine coolant.

The integrated apparatus 1 of the present invention is described in detail below.

Referring to FIG. 2, in principle, the integrated apparatus 1 of the present invention integrates the functions of a urea pump 11 and a urea nozzle 12. The urea pump 11 comprises but is not limited to a gear pump, diaphragm pump, plunger pump or vane pump, etc. It should be understood that the term “integrated” used here means that the urea pump 11 and the urea nozzle 12 may be mounted as a single apparatus on a gas intake pipe or the exhaust pipe; or the urea pump 11 and the urea nozzle 12 are close to each other and connected via a short connecting pipeline, and can on the whole be regarded as one apparatus.

Furthermore, in order to subject the urea pump 11 and the urea nozzle 12 to independent control, the exhaust gas post-processing system 100 of the present invention is also provided with a controller 13. It can be understood that the controller 13 may be integrated with the integrated apparatus 1 or arranged separately from the integrated apparatus 1. Referring to FIG. 2, in an embodiment shown in the figures of the present invention, the controller 13 is integrated in the integrated apparatus 1, to realize a high degree of integration of components, and make installation at a customer end more convenient.

The integrated apparatus 1 is provided with a housing 14 for accommodating the urea pump 11 and the urea nozzle 12. The embodiment shown in FIG. 2 merely shows the housing 14 roughly. For example, in an 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 cooperating with the urea pump 11 and a second housing cooperating with the urea nozzle 12, with the first housing and the second housing being fitted together, to form a whole. 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 and the urea nozzle 12. It must be explained that “inlet” in the term “inlet passage 15” used here and “outlet” in “outlet passage 16” take the urea pump 11 as a reference, i.e. the inlet is upstream of the urea pump 11, and the outlet is downstream of the urea pump 11. The outlet passage 16 is in communication with the urea nozzle 12, in order to pump the urea solution toward 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.

Furthermore, the integrated apparatus 1 is provided with a temperature sensor 171 for detecting temperature. The temperature sensor 171 may be configured to be in communication with the inlet passage 15 and/or the outlet passage 16; or the temperature sensor 171 may be configured to be mounted in any position in the integrated apparatus 1. A signal detected by the temperature sensor 171 is transmitted to the controller 13; a control algorithm of the controller 13, designed on the basis of this inputted signal and other signals, can improve the injection precision of the urea nozzle 12. The integrated apparatus 1 is also provided with a pressure sensor 172 for detecting pressure; the pressure sensor 172 is in communication with the outlet passage 16, in order to detect pressure in the high-pressure passage of the outlet of the urea pump 11. Due to the integrated design of the present invention, distances in the interior passages are relatively short, therefore the position of the pressure sensor 172 may be regarded as being relatively close to the urea nozzle 12. An advantage of such a design is that the pressure measured by the pressure sensor 172 is relatively close to the pressure in the urea nozzle 12, so data precision is improved, thereby improving the injection precision of the urea nozzle 12. In an embodiment of the present invention, the temperature sensor 171 and the pressure sensor 172 are two elements; in another embodiment of the present invention, the temperature sensor 171 and the pressure sensor 172 are one element, but simultaneously have the functions of detecting temperature and pressure.

Referring to FIG. 2, the integrated apparatus 1 is also provided with an overflow element 173 connected between the outlet passage 16 and the inlet passage 15. The overflow element 173 comprises but is not limited to an overflow valve, a safety valve or an electrical control valve, etc. 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 a set value, and release urea solution located in the high-pressure passage into the low-pressure passage or return it directly into the urea tank 201, to realize pressure regulation.

In order to drive the urea pump 11, the urea pump 11 is provided with an electric machine coil 111 which communicates with the controller 13. In order to drive the urea nozzle 12, the urea nozzle 12 is provided with a nozzle coil 121 which communicates with the controller 13.

The controller 13 communicates with the temperature sensor 171 and the pressure sensor 172, in order to transmit temperature signals and pressure signals to the controller 13. Of course, in order to be able to achieve precise control, the controller 13 may also receive other signals, e.g. signals from a CAN bus which are associated with engine running parameters. Furthermore, the controller 13 may also obtain a rotation speed of the urea pump 11; of course, the acquisition of rotation speed signals may be realized by means of a corresponding rotation speed sensor 175 (hardware) or by means of a control algorithm (software). The rotation speed sensor 175 may be a Hall sensor, etc. The controller 13 subjects the urea pump 11 and the urea nozzle 12 respectively to independent control. An advantage of such control is the ability to reduce the effect of actions of the urea pump 11 on the urea nozzle 12, in order to achieve relatively high control precision.

Furthermore, in certain operating conditions, since the exhaust gas of the engine has a high temperature, and the urea nozzle 12 is generally mounted on the exhaust pipe, it is necessary to cool the urea nozzle 12. For this purpose, the integrated apparatus 1 is also provided with a cooling component, which cools the urea nozzle 12 by means of a cooling medium. The cooling medium comprises but is not limited to air, and/or engine coolant, and/or lubricating oil, and/or urea, etc. Referring to FIG. 2, an embodiment shown in the figures of the present invention employs water cooling, i.e. uses engine coolant to cool the urea nozzle 12. A cooling passage 141 for allowing engine coolant to circulate is provided in the housing 14.

Referring to FIG. 2, the main principles of operation of the integrated apparatus 1 are as follows:

The controller 13 drives the urea pump 11 to operate; urea solution located in the urea tank 201 is drawn into the urea pump 11 through the inlet passage 15, and after being pressurized, is delivered to the urea nozzle 12 through the outlet passage 16. Here, the controller 13 acquires and/or calculates necessary signals, e.g. temperature, pressure, pump rotation speed, etc. When an injection condition is attained, the controller 13 issues a control signal to the urea nozzle 12, e.g. energizes the nozzle coil 121, and realizes the injection of urea by controlling the movement of a valve needle. The controller 13 issues a control signal to the urea pump 11 to control the rotation speed thereof, thereby stabilizing the pressure of the system. In an embodiment shown in the figures of the present invention, the controller 13 subjects the urea pump 11 and the urea nozzle 12 respectively to independent control.

Referring to FIGS. 3-37, from a structural point of view, in an embodiment shown in the figures of the present invention, the integrated apparatus 1 comprises a pump component 18 and a nozzle component 19. Referring to FIGS. 3-5, the nozzle component 19 is at least partially inserted into the pump component 18, and fixed thereto by welding.

Referring to FIGS. 3-13, in an embodiment shown in the figures of the present invention, the pump component 18 comprises an electric machine casing assembly 181, a magnetic cover component 6 at least partially located in the electric machine casing assembly 181, and a pump housing assembly 182 cooperating with the electric machine casing assembly 181.

Referring to FIGS. 6-9, the electric machine casing assembly 181 comprises an electromagnetic shielding cover 183, the electric machine coil 111 at least partially located in the electromagnetic shielding cover 183, and the controller 13. In an embodiment shown in the figures of the present invention, the electromagnetic shielding cover 183 is made of a metal material in order to reduce interference from external factors affecting internal electronic components, etc. and at the same time can also reduce the effect of internal electronic components on other external electronic devices. The electric machine casing assembly 181 also comprises a cover shell 2 injection-molded at the periphery. The cover shell 2 comprises a cover shell cavity 21 for covering the controller 13 and at least a part of the pump component 18, a through-hole 22 in communication with the cover shell cavity 21, and a waterproof gas-permeable cap 24 fixed in the through-hole 22. The electric machine coil 111 is electrically connected to the controller 13. In an embodiment shown in the figures of the present invention, the controller comprises a circuit board 131 with a number of electronic components arranged thereon. The electronic components will emit heat during operation, causing air at the periphery thereof to expand; through the provision of the waterproof gas-permeable cap 24, the present invention effectively solves the problem of chips and/or electronic components being damaged by pressure due to the expansion of air, and at the same time can also achieve a waterproofing effect. Furthermore, the waterproof gas-permeable cap 24 can improve the environment of the controller 13, enabling it to satisfy operating conditions.

In an embodiment shown in the figures of the present invention, the circuit board 131 is annular, and is provided with a central hole 135 located in a middle part. A connection insertion member 132 connected to the circuit board is injection-molded on the cover shell 2. Furthermore, the electric machine casing assembly 181 also comprises a heat dissipating pad 130 covering a surface of the electronic components. With this configuration, the temperature of the electronic components can be made uniform by means of the heat dissipating pad 130, thereby avoiding damage to the electronic components due to local overheating.

The magnetic cover component 6 comprises a metal cover 62 at least partially inserted into the electric machine coil 111, a sheet part 61 located below the metal cover 62, and a rotor 72 received in the metal cover 62, etc. The metal cover 62 protrudes upward from the sheet part 61. The metal cover 62 passes through the central hole 135 of the circuit board 131 in an upward direction, and is at least partially inserted into the electric machine coil 111. Referring to FIGS. 19-22, the sheet part 61 is screwed onto the pump housing assembly 182 by means of a number of screws 133, in order to fix the magnetic cover component 6. The pump component 18 also comprises an elastic body 71 received in the metal cover 62 and located below the rotor 72; the elastic body 71 can also be compressed in order to absorb an expansion volume caused by the freezing of urea. Referring to FIG. 33, the electric machine coil 111 is connected in a surrounding manner at the periphery of the metal cover 62.

The pump housing assembly 182 comprises a first housing 3, a second housing 4 and a third housing 5 which are stacked together in sequence from top to bottom. In an embodiment shown in the figures of the present invention, the first housing 3, the second housing 4 and the third housing 5 are all made of a metal material.

In an embodiment shown in the figures of the present invention, the urea pump 11 is a gear pump, and comprises the electric machine coil 111, the metal cover 62, the rotor 72 located in the metal cover 62, a first sealing ring 73 located below the metal cover 62, and a first gear component 74 and a second gear component 75 which are meshed with each other, etc. Since the gear pump can establish a relatively high operating pressure, it is favorable for increasing the flow rate of the urea nozzle 12. Furthermore, the gear pump can also rotate in reverse, which is favorable for drawing out residual urea solution completely, reducing the risk of urea crystallizing.

Referring to FIGS. 14 to 28, in an embodiment shown in the figures of the present invention, the first housing 3, the second housing 4 and the third housing 5 are machined members, and are fixed together by means of bolts 66. The first housing 3 is provided with a laterally located engagement groove 34 and an O-shaped sealing ring 35 engaged in the engagement groove 34. In an embodiment shown in the figures of the present invention, the first housing 3 and the electric machine casing assembly 181 are fixed together by roll extrusion or welding, and piston sealing is performed by means of the O-shaped sealing ring 35.

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

The first island 312 is provided with a first positioning hole 3121 running through the first lower surface 32, a second positioning hole 3122 running through the first lower surface 32, a first outlet hole 3123 running through the first upper surface 31 and being in communication with the outlet passage 16, and a first flow-guiding groove 3124 running through the first upper surface 31 and being in communication with the second positioning hole 3122. The urea pump 11 is provided with a first shaft sleeve 76 received in the first positioning hole 3121, and a second shaft sleeve 77 received in the second positioning hole 3122. The first housing 3 also comprises a number of first assembly holes 318 allowing the bolts 66 to pass through; the first assembly holes 318 run through the first upper surface 31 and the first lower surface 32. The first upper surface 31 is also provided with a sensor receiving hole 313, located at a side of the first island 312 and used for receiving a sensor 174; the sensor 174 simultaneously has the functions of detecting temperature and pressure. The first housing 3 is also provided with a second outlet hole 3125 establishing communication between the outlet passage 16 and the sensor receiving hole 313.

Furthermore, referring to FIG. 24, the first housing 3 is provided with a liquid entry passage 332, which runs through the first side 33 in order to be connected to a urea connector 331. Referring to FIGS. 15 and 16, the urea connector 331 comprises a filter mesh 3311 close to an outer side and a freeze-resistant element 3312 close to an inner side, wherein the filter mesh 3311 can filter impurities in the urea solution, and the freeze-resistant element 3312 can absorb an expansion volume when urea freezes, thereby reducing the risk of being damaged by freezing. The first housing 3 is provided with a connecting hole 3127, which runs through the first lower surface 32 and is in communication with the liquid entry passage 332. The first outlet hole 3123 and the connecting hole 3127 are both perpendicular to the liquid entry passage 332. The first positioning hole 3121, the second positioning hole 3122 and the connecting hole 3127 all run through the second island 326 in a downward direction. The first lower surface 32 is provided with a first load release groove 321 establishing communication between the first positioning hole 3121 and the second positioning hole 3122, to ensure pressure balance. The first load release groove 321 is located on the second island 326. Furthermore, the first housing 3 is also provided with a receiving cavity 322, which runs through the first lower surface 32 in a downward direction and is used for receiving at least a part of the nozzle component 19. Referring to FIGS. 33 and 34, 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.

Furthermore, referring to FIGS. 14 to 16, 22 and 24, the first housing 3 is also provided with an overflow element receiving slot 319, which is in communication with the liquid entry passage 332 and the receiving cavity 322. The overflow element receiving slot 319 runs through the first side 33 in an outward direction, in order to receive the overflow element 173. In an embodiment shown in the figures of the present invention, the overflow element 173 is a safety valve, and is intended to ensure, by releasing pressure, that the pressure in the high-pressure passage in the integrated apparatus 1 is within a range of safe values. In order to fix the overflow element 173, the first housing 3 is provided with a plug 5122 for fixing the overflow element 173.

Referring to FIG. 1, the urea connector 331 is in communication with the urea tank 201 via a urea connecting pipe 333. In order to better realize the function of heating and thawing, the exhaust gas post-processing system 100 may also be provided with a heating apparatus 334 for heating the urea connecting pipe 333. Referring to FIG. 24, in an embodiment shown in the figures of the present invention, the liquid entry passage 332 extends horizontally into the interior of the first housing 3. Of course, in other embodiments, the liquid entry passage 332 could also be at a certain angle.

Referring to FIGS. 25 to 27, the first gear component 74 comprises a first gear shaft 741 and a first gear 742 fixed to the first gear shaft 741; the second gear component 75 comprises a second gear shaft 751 and a second gear 752 fixed to the second gear shaft 751, with the first gear 742 and the second gear 752 being meshed with each other. Referring to FIG. 34, in an embodiment shown in the figures of the present invention, the first gear 742 and the second gear 752 are meshed externally. Furthermore, 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. An upper end of the first gear shaft 741 passes through the first shaft sleeve 76 and is fixed to the rotor 72. An upper end of the second gear shaft 751 is positioned in the second shaft sleeve 77. When the electric machine coil 111 is energized, it interacts with a magnetic body 72; an electromagnetic force will drive the first gear shaft 741 to rotate, and thereby drive 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 connected to the first housing 3. Furthermore, in order to achieve better positioning, a number of positioning pins 328 are also provided between the first housing 3 and the second housing 4. The second housing 4 comprises a second upper surface 41, a second lower surface 42, and a gear slot 43 which runs through the second upper surface 41 and the second lower surface 42 and is used for receiving the first gear 742 and the second gear 752. One side of the gear slot 43 is provided with a liquid entry cavity 431 in communication with the inlet passage 15, and another side of the gear slot 43 is provided with a liquid exit cavity 432 in communication with the outlet passage 16. Specifically, the liquid entry cavity 431 is in communication with the connecting hole 3127, and an upper end of the liquid exit cavity 432 is in communication with the first outlet hole 3123. Furthermore, in order to improve the freeze-resistance of the product, the second housing 4 is also provided with a first freeze-resistant rod 441 located in the liquid entry cavity 431 and a second freeze-resistant rod 442 located in the liquid exit cavity 432; the first freeze-resistant rod 441 and the second freeze-resistant rod 442 can both be compressed when urea freezes.

Furthermore, the second housing 4 is also provided with an accommodating hole 411 allowing at least a part of the nozzle component 19 to pass through. The nozzle component 19 partially protrudes from the second upper surface 41 in an upward direction and is received in the receiving cavity 322. With this configuration, high-pressure urea solution can be delivered to the urea nozzle 12. The second housing 4 also comprises a number of second assembly holes 418 aligned with the first assembly holes 318.

Referring to FIG. 28, 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 part 51, a protruding part 52 extending downward from the body part 51, and a flange 53 extending outward from the body part 51, wherein the flange 53 is provided with a number of third assembly holes 531 aligned with the second assembly holes 418, for allowing the bolts 66 to pass through. The body part 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 513 surrounded by the third annular groove 512. The third annular groove 512 is used for receiving a third sealing ring 732.

During operation, urea solution enters the liquid entry passage 332 from the urea connecting pipe 333, and enters the liquid entry cavity 431 via the connecting hole 3127; after being pressurized by the gear pump, a portion of high-pressure urea solution passes through the first outlet hole 3123 in an upward direction and enters the metal cover 62, and another portion of high-pressure urea solution enters a second flow-guiding groove 5114 and a third flow-guiding groove 5115 in a downward direction; a portion of urea solution located in the metal cover 62 enters the second shaft sleeve 77 from the first flow-guiding groove 3124, and then enters the first shaft sleeve 76 via the first load release groove 321, in order to improve the smoothness of rotation of the gear pump, and reduce wear; another portion of urea solution located in the metal cover 62 enters the receiving cavity 322 from the second outlet hole 3125 in order to flow toward the nozzle component 19, and at the same time a portion of urea solution flows toward the overflow element 173. When the pressure is less than a set value of the overflow element 173, the overflow element 173 is closed; when the pressure is greater than a set value of the overflow element 173, the overflow element 173 opens, and a portion of urea solution enters the liquid entry passage 332, to achieve pressure release.

It can be understood that in an embodiment shown in the figures of the present invention, the inlet passage 15 comprises the liquid entry passage 332, the connecting hole 3127 and the liquid entry cavity 431. Due to being located upstream of the urea pump 11, the inlet passage 15 is called the low-pressure passage. The outlet passage 16 comprises the liquid exit cavity 432, the first outlet hole 3123, the second outlet hole 3125 and the receiving cavity 322, etc. Due to being located downstream of the urea pump 11, the outlet passage 16 is called the high-pressure passage.

Referring to FIGS. 13 and 29 to 32, the nozzle component 19 comprises a nozzle assembly 120 and a water-cooled base 190 connected in a surrounding manner at the outside of the nozzle assembly 120. In an embodiment shown in the figures of the present invention, the nozzle assembly 120 and the water-cooled base 190 together form the urea nozzle 12.

In an embodiment shown in the figures of the present invention, the nozzle assembly 120 comprises a nozzle coil 121, a magnetic part 81 interacting with the nozzle coil 121, a valve needle part 82 located below the magnetic part 81, a spring 83 which acts between the magnetic part 81 and the valve needle part 82, and a valve seat 84 which cooperates with the valve needle part 82 (see FIG. 30), etc. The nozzle coil 121 is located at the periphery of the magnetic part 81; the nozzle assembly 120 also comprises a first sleeve 811 which at last partially receives the magnetic part 81, and a second sleeve 812 which at least partially receives the valve needle part 82. Furthermore, the nozzle assembly 120 also comprises a sleeve part 122 connected in a surrounding manner at the periphery of the nozzle coil 121. The spring 83 is mounted in the magnetic part 81 and the valve needle part 82. The valve needle part 82 is provided with a tapered part 821, and a valve needle 822 extending downward from the tapered part 821.

The first sleeve 811 and the second sleeve 812 are fixed together to form a space 813 around the periphery of the valve needle part 82; the valve needle 822 is provided with a through-hole 814 in communication with the space 813. The nozzle assembly 120 also comprises a rotational flow plate 85, which is manufactured separately from the valve seat 84 and is in close abutment with the valve seat 84; the rotational flow plate 85 is provided with a number of rotational flow grooves 851. The second sleeve 812 is provided with a communication groove 815 establishing communication between the space 813 and the rotational flow grooves 851. The valve seat is provided with an injection hole 841 cooperating with the valve needle 822.

Referring to FIG. 30, a fourth sealing ring 816 is connected in a surrounding manner to an upper end of the magnetic part 81, in order to achieve sealing with an inner wall of the receiving cavity 322. Furthermore, the nozzle assembly 120 also comprises a terminal encapsulation part 86 connected to the nozzle coil 121; a fifth sealing ring 817 is connected in a surrounding manner to the terminal encapsulation part 86.

The water-cooling base 190 comprises a main body part 91, a mounting slot 92 running through the main body part 91 in a downward direction, and a mounting flange 93 extending outward from the main body part 91. The mounting flange 93 is provided with a number of mounting holes 931 for mounting the integrated apparatus 1 onto the exhaust pipe 106 or the encapsulated system 300.

The cooling passage 141 located in the water-cooled base 190 comprises a first cooling passage 913, 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 connector 103; the second cooling passage 914 is in communication with the outlet connector 104. The water-cooled base 190 is provided with an end cap 96 sealed at the periphery of the mounting slot 92 (see FIG. 33). In an embodiment shown in the figures of the present invention, the end cap 96 is welded in the mounting slot 92. With this configuration, the water-cooled base 190 forms an annular cooling groove 916 establishing communication between the first cooling passage 914 and the second cooling passage 915, between the end cap 96 and the second sleeve 812.

In an embodiment shown in the figures of the present invention, the mounting flange 93 and the main body part are integrally formed by machining. Of course, in other embodiments, the mounting flange 93 could also be manufactured separately from the main body part 91, and then welded thereto.

It can be understood that in other embodiments of the present invention, for example the integrated apparatus is used for the injection of fuel into engine exhaust gas, in order to achieve the regeneration of a downstream diesel particulate filter (DPF). In such an application, the urea pump 11 may be replaced by a fuel pump, the urea nozzle 12 may be replaced by a fuel nozzle, and the urea solution may be replaced by fuel. Such a change is understandable to a person skilled in the art, and is not further described superfluously here.

To facilitate understanding of the present invention, the urea pump and the fuel pump are collectively called pumps, the urea nozzle and the fuel nozzle are collectively called nozzles, and the urea solution and the fuel are collectively called fluid media.

Compared with the prior art, the integrated apparatus 1 of the present invention has an integrated design, which can omit or shorten the urea pipe used for connecting the pump to the nozzle in the prior art, can also omit insertion connection members between various sensors and wire bundles in the pump supply unit in the prior art, and need not have any heating/thawing apparatus, so reliability is high. The integrated apparatus 1 of the present invention is structurally compact, small in volume, and easy to mount in various models of vehicle. Furthermore, internal fluid medium passages in the integrated apparatus 1 of the present invention are short, with a small pressure drop; dead volume between the pump and the nozzle is small, and efficiency is high. The sensor 174 is close to the nozzle, and injection pressure precision is high. Furthermore, by subjecting the pump and the nozzle respectively to independent control, a situation where an action of the nozzle is driven by an action of the pump is avoided, and the precision of control is thereby improved. Due to the fact that the injection precision of the nozzle is improved, a suitable ratio can be attained between the amount of urea injected into exhaust gas, and nitrogen oxides, reducing the risk of crystallization caused by excessive injection of urea. The integrated apparatus 1 of the present invention may employ water cooling, such that the temperature of urea remaining in the integrated apparatus 1 is unable to reach the crystallization point, so crystallization will not readily occur.

The embodiments above are merely intended to explain the present invention, without limiting the technical solution described by the present invention. An understanding of this Description should take those skilled in the art as a foundation. Although the present invention has been explained in detail herein with reference to the embodiments above, those of ordinary skill in the art should understand that those skilled in the art could still make amendments to or equivalent substitutions in the present invention, and all technical solutions and improvements thereof which do not diverge from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An integrated apparatus of a pump and a nozzle, wherein the pump is used for pumping a fluid medium toward the nozzle, and the nozzle is used for injecting the fluid medium into intake gas or exhaust gas of an engine, characterized in that the integrated apparatus comprises a pump component and a nozzle component; the pump component comprises an electric machine casing assembly, a magnetic cover component at least partially located in the electric machine casing assembly, and a pump housing assembly cooperating with the electric machine casing assembly; the electric machine casing assembly comprises an electromagnetic shielding cover, and an electric machine coil at least partially located in the electromagnetic shielding cover; the magnetic cover component comprises a metal cover at least partially inserted into the electric machine coil, and a rotor received in the metal cover; the electric machine casing assembly and the pump housing assembly are fixed together by roll extrusion or welding; the pump housing assembly 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, wherein the outlet passage is in communication with the nozzle component; the pump housing assembly further comprises a first gear component and a second gear component meshed with each other, wherein the first gear component comprises a first gear shaft and a first gear, the second gear component comprises a second gear shaft and a second gear, the first gear and the second gear being meshed with each other, and the rotor being fixed to the first gear shaft; the nozzle component comprises a nozzle assembly, and a water-cooled base connected in a surrounding manner at the outside of the nozzle assembly, wherein the nozzle assembly comprises a nozzle coil for driving the nozzle.

2. The integrated apparatus as claimed in claim 1, wherein the pump is a urea pump, the nozzle is a urea nozzle, and the fluid medium is a urea solution.

3. The integrated apparatus as claimed in claim 1, wherein the pump is a fuel pump, the nozzle is a fuel nozzle, and the fluid medium is a fuel.

4. The integrated apparatus as claimed in claim 2, wherein the controller subjects the urea pump and the urea nozzle respectively to independent control; the electric machine casing assembly comprises a controller, the controller comprising a circuit board, with the electric machine coil and the nozzle coil both being connected to the circuit board.

5. The integrated apparatus as claimed in claim 2, wherein the integrated apparatus comprises a sensor, in communication with the outlet passage in order to detect temperature and pressure, and an overflow element connected between the outlet passage and the inlet passage.

6. The integrated apparatus as claimed in claim 2, wherein the first gear shaft is a driving shaft, the second gear shaft is a driven shaft, and the first gear shaft is higher than the second gear shaft.

7. The integrated apparatus as claimed in claim 2, wherein a freeze-resistant body located above the rotor is further provided in the metal cover, the freeze-resistant body being compressible in order to absorb an expansion volume caused by the freezing of urea.

8. The integrated apparatus as claimed in claim 7, wherein the pump component further comprises an elastic body received in the metal cover and located below the rotor, the elastic body being compressible in order to absorb an expansion volume caused by the freezing of urea.

9. The integrated apparatus as claimed in claim 2, wherein the pump housing assembly is provided with a gear slot receiving the first gear and the second gear, the first gear and the second gear are meshed externally, one side of the gear slot is provided with a liquid entry cavity in communication with the inlet passage, and another side of the gear slot is provided with a liquid exit cavity in communication with the outlet passage.

10. The integrated apparatus as claimed in claim 9, wherein the pump housing assembly is further provided with a first freeze-resistant rod located in the liquid entry cavity and a second freeze-resistant rod located in the liquid exit cavity; the first freeze-resistant rod and the second freeze-resistant rod are both compressible when urea freezes.

11. The integrated apparatus as claimed in claim 1, wherein the nozzle assembly comprises a magnetic part interacting with the nozzle coil, a first sleeve at least partially receiving the magnetic part, a valve needle part located below the magnetic part, a second sleeve at least partially receiving the valve needle part, a spring acting between the magnetic part and the valve needle part, a valve seat cooperating with the valve needle part, and a rotational flow plate which is manufactured separately from the valve seat and is in close abutment with the valve seat; the rotational flow plate is provided with a number of rotational flow grooves.

12. The integrated apparatus as claimed in claim 11, wherein the nozzle coil is located at the periphery of the magnetic part, the valve needle part is provided with a valve needle, the first sleeve and the second sleeve are fixed together to form a space around the periphery of the valve needle part, the valve needle is provided with a through-hole in communication with the space, the second sleeve is provided with a communication groove establishing communication between the space and the rotational flow grooves, and the valve seat is provided with an injection hole cooperating with the valve needle.

13. The integrated apparatus as claimed in claim 1, wherein the electric machine casing assembly is provided with an injection-molded connection insertion member electrically connected to the circuit board, a number of electronic components are mounted on the circuit board, and the electric machine casing assembly further comprises a heat dissipating pad covering a surface of the electronic components.

14. The integrated apparatus as claimed in claim 9, wherein the magnetic cover component comprises a sheet part located below the metal cover, the sheet part being fixed to the pump housing assembly by means of a number of screws.

15. The integrated apparatus as claimed in claim 14, wherein the pump housing assembly comprises a first housing, the first housing comprising a first upper surface, a first lower surface and a first side, wherein the first upper surface is provided with a first annular groove, a first island surrounded by the first annular groove, and a first sealing ring received in the first annular groove, with the sheet part pressing down on the first sealing ring; the first island is provided with a first positioning hole running through the first lower surface, and a second positioning hole running through the first lower surface; the urea pump comprises a first shaft sleeve received in the first positioning hole, and a second shaft sleeve received 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.

16. The integrated apparatus as claimed in claim 15, wherein the first lower surface is provided with a first load release groove establishing communication between the first positioning hole and the second positioning hole.

17. The integrated apparatus as claimed in claim 15, wherein the first island further comprises a first flow-guiding groove running through the first upper surface and in communication with the second positioning hole, and a first outlet hole running through the first upper surface and in communication with the liquid exit cavity; the first upper surface is further provided with a sensor receiving hole, located at a side of the first island and used for receiving a sensor, and the integrated apparatus comprises the sensor for detecting temperature and pressure; the first housing is further provided with a second outlet hole in communication with the sensor receiving hole.

18. The integrated apparatus as claimed in claim 17, wherein the first housing is provided with an overflow element receiving slot, and the integrated apparatus is provided with an overflow element mounted in the overflow element receiving slot; when a pressure of the outlet passage is higher than a set value, the overflow element opens in order to return a portion of the urea solution into the inlet passage.

19. The integrated apparatus as claimed in claim 15, wherein the pump housing assembly comprises a second housing, located below the first housing and connected to the first housing; the second housing comprises a second upper surface and a second lower surface, with the gear slot running through the second upper surface and the second lower surface.

20. The integrated apparatus as claimed in claim 19, wherein the pump housing assembly comprises a third housing, located below the second housing and connected to the second housing; the third housing comprises a body part, and a protruding part extending downward from the body part, wherein the body part is provided with a third upper surface, with the third upper surface being provided with a third annular groove and a third island surrounded by the third annular groove; the third island is provided with a third positioning hole and a fourth positioning hole running through the third upper surface, the third positioning hole and the fourth positioning hole extending into the protruding part; the urea pump comprises a third shaft sleeve received in the third positioning hole, and a fourth shaft sleeve received 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.

21. The integrated apparatus as claimed in claim 20, wherein the third island is provided with a second flow-guiding groove and a third flow-guiding groove running through the third upper surface, wherein the second flow-guiding groove is in communication with the third positioning hole, and the third flow-guiding groove is in communication with the fourth positioning hole.

22. The integrated apparatus as claimed in claim 20, wherein the nozzle assembly comprises a magnetic part interacting with the nozzle coil, a valve needle part located below the magnetic part, a spring acting between the magnetic part and the valve needle part, and a valve seat cooperating with the valve needle part.

23. The integrated apparatus as claimed in claim 22, wherein the nozzle assembly further comprises a first sleeve at least partially receiving the magnetic part, and a second sleeve at least partially receiving the valve needle part; the spring is mounted in the magnetic part and the valve needle part; the valve needle part is provided with a tapered part, and a valve needle extending downward from the tapered part; the first sleeve and the second sleeve are fixed together to form a space around the periphery of the valve needle part, and the valve needle is provided with a through-hole in communication with the space.

24. The integrated apparatus as claimed in claim 23, wherein the nozzle assembly further comprises a rotational flow plate, manufactured separately from the valve seat and in close abutment with the valve seat, the rotational flow plate being provided with a number of rotational flow grooves; the second sleeve is provided with a communication groove establishing communication between the space and the rotational flow grooves, and the valve seat is provided with an injection hole cooperating with the valve needle.

25. The integrated apparatus as claimed in claim 24, wherein 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 the periphery of the mounting slot; between the end cap and the second sleeve, the nozzle assembly forms an annular cooling groove establishing communication between the first cooling passage and the second cooling passage; the first cooling passage is connected to an inlet connector to allow the injection of an engine coolant, and the second cooling passage is connected to an outlet connector to allow the engine coolant to flow out.

26. An exhaust gas post-processing system, comprising an injection system of exhaust gas post-processing and an encapsulated system of exhaust gas post-processing, wherein the injection system comprises the integrated apparatus as claimed in claim 1, and the encapsulated system comprises a support located downstream of the integrated apparatus.

27. The exhaust gas post-processing system as claimed in claim 26, wherein the support comprises selective catalytic reduction, and the encapsulated system further comprises at least one mixer located between the integrated apparatus and the support.

28. A control method for an integrated apparatus, wherein the integrated apparatus is the integrated apparatus as claimed in claim 1, the control method comprising:

driving the rotor to operate, thereby driving the pump to rotate, and drawing the fluid medium into the pump through the inlet passage;

after pressurization by the pump, delivering the fluid medium to the nozzle through the outlet passage;

when an injection condition is attained, energizing the nozzle coil, and at least partially opening the nozzle in order to inject the fluid medium into intake gas or exhaust gas of the engine, wherein:

the electric machine coil and the nozzle coil are respectively subjected to independent control.