Split type urea pump

Abstract

The utility model discloses a split type urea pump which comprises an upper cover assembly, a middle shell assembly and a lower cover assembly which are detachably connected in sequence from top to bottom. The upper cover assembly comprises an upper cover and a PCBA (Printed Circuit Board Assembly) board which is arranged on one side, facing the middle shell assembly, of the upper cover; the middle shell assembly comprises a middle shell as well as a main pump, a reflux pump and a runner block which are mounted in the middle shell; a liquid inlet pipe joint, a return pipe joint and an injection pipe joint are respectively arranged on the middle shell; the liquid inlet pipe joint is communicated with a liquid inlet of the main pump, and a liquid outlet of the main pump is communicated with the injection pipe joint; the reflux pipe joint is communicated with a liquid outlet of the reflux pump, and a liquid inlet of the reflux pump is communicated with a liquid outlet of the main pump; the runner block is arranged between the liquid inlet of the main pump and the liquid inlet pipe joint; and sealing pieces are arranged at a liquid inlet and a liquid outlet of the main pump. The utility model can effectively reduce the requirement on the installation space, is beneficial to the space arrangement of the whole vehicle, and is convenient to assemble, disassemble and maintain.

Description

TECHNICAL FIELD

[0001] The utility model relates to urea pump technical field, more specifically, the utility model relates to a split type urea pump. BACKGROUND

[0002] In order to meet the strict standards required by the state, each automobile and engine manufacturer needs to add a set of engine exhaust aftertreatment system in the automobile system. The main working principle of the system is to inject urea solution into the exhaust gas as a reducing agent before the exhaust gas enters the catalyst, to realize the reduction of NOx, so as to achieve the effect of reducing NOx emission, so as to achieve the purpose of protecting the environment. In the whole exhaust aftertreatment system, the urea pump is a key component, which is used to uniformly and stably mix the urea solution with a certain pressure with the exhaust gas. According to the installation mode, the urea pump on the market is mostly integral type, but the integral type urea pump has high requirements for the installation space of the whole vehicle, and is not suitable for the case where the installation space is limited, and the disassembly and assembly are not convenient, which affects the maintenance efficiency. SUMMARY

[0003] An object of the utility model is to solve at least the above problems, and provide at least the advantages to be explained later.

[0004] In order to realize these purposes and other advantages according to the utility model, a split type urea pump is provided, which comprises upper cover assembly, middle shell assembly and lower cover assembly which are detachably connected in sequence from top to bottom; the upper cover assembly comprises an upper cover and a PCBA board installed on the side of the upper cover facing the middle shell assembly; the middle shell assembly comprises a middle shell and a main pump, a return pump and a flow channel block installed in the middle shell; the middle shell is provided with a liquid inlet connector, a return pipe connector and a spray pipe connector respectively; the liquid inlet connector is in communication with the liquid inlet of the main pump, and the liquid outlet of the main pump is in communication with the spray pipe connector; the return pipe connector is in communication with the liquid outlet of the return pump, and the liquid inlet of the return pump is in communication with the liquid outlet of the main pump; the flow channel block is arranged between the liquid inlet of the main pump and the liquid inlet connector; sealing elements are arranged at the liquid inlet and the liquid outlet of the main pump.

[0005] Preferably, heating fins are arranged in the middle shell corresponding to the flow channel block.

[0006] Preferably, the main pump and the return pump each comprise a pump body and a driving assembly, and the pump body and the driving assembly are connected as a whole through buckle connection.

[0007] Preferably, an axial sealing element is arranged at the liquid inlet of the main pump, and a radial sealing element is arranged at the liquid outlet of the main pump.

[0008] Preferably, the PCBA board is provided with a connector, the connector is provided with a sealing gasket at the connecting position with the upper cover, and the PCBA board is provided with a screw mounting hole corresponding to the outer periphery of the sealing gasket.

[0009] Preferably, the lower cover assembly comprises a lower cover arranged at the bottom of the middle shell and a lower sealing gasket arranged at the connecting position of the lower cover and the middle shell.

[0010] Preferably, a pressure sensor is arranged between the liquid outlet of the main pump and the spray pipe joint.

[0011] The utility model at least has following beneficial effects:

[0012] 1. The split type urea pump can install the upper cover assembly, the middle shell assembly and the lower cover assembly respectively, effectively reduces the requirement for installation space, is favorable to vehicle space arrangement, and is convenient to assemble and disassemble and maintain.

[0013] 2. The split type urea pump is provided with different sealing forms at the liquid inlet and the liquid outlet of the main pump, which can meet the sealing requirement and facilitate the installation of the main pump.

[0014] Other advantages, objects and features of the utility model will be embodied partly through the following description, and will be understood by the person skilled in the art through the research and practice of the utility model. DRAWINGS

[0015] Figure 1 It is a structure schematic view of the split type urea pump of the utility model;

[0016] Figure 2 It is an internal structure exploded view of the middle shell assembly of the utility model;

[0017] Figure 3 It is a working process schematic view of the split type urea pump of the utility model;

[0018] Figure 4 It is a structure schematic view of the main pump of the utility model; DETAILED DESCRIPTION

[0019] The utility model will be further described in detail in combination with the drawings, so that the person skilled in the art can implement according to the description.

[0020] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this utility model, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] like Figures 1 to 3 As shown, this utility model provides a split-type urea pump, including an upper cover assembly 10, a middle housing assembly 20, and a lower cover assembly 30 that are detachably connected from top to bottom; the upper cover assembly 10 includes an upper cover and a PCBA board installed on the side of the upper cover facing the middle housing assembly; the middle housing assembly 20 includes a middle housing 21 and a main pump 22, a return pump 24, and a flow channel block 29 installed inside the middle housing 21; the middle housing 21 is respectively provided with an inlet pipe connector 28 and a return pipe. The system includes a connector 26 and a jet pipe connector 27; the inlet pipe connector 28 is connected to the inlet of the main pump 22, and the outlet of the main pump 22 is connected to the jet pipe connector 27; the return pipe connector 26 is connected to the outlet of the return pump 24, and the inlet of the return pump 24 is connected to the outlet of the main pump 22; the flow channel block 29 is disposed between the inlet of the main pump 22 and the inlet pipe connector 28; and a seal is provided at both the inlet and outlet of the main pump 22.

[0022] In this technical solution, the split-type urea pump can separately install the upper cover assembly 10, the middle housing assembly 20, and the lower cover assembly 30, effectively reducing the requirements for installation space, which is beneficial for the overall vehicle space layout. Furthermore, it is easy to install and remove, and convenient for maintenance. The main working components of the split-type urea pump are concentrated within the middle housing 21, and the working process is as follows: Figure 2As shown, the urea solution in the urea tank is sequentially passed through the liquid inlet connector 28, the flow channel block 29 and the main pump 22 for pressurization, and then is sprayed out after being connected with the spray pipe through the spray pipe connector 27. The residual urea solution in the pipeline connected with the liquid outlet of the main pump 22 and the spray pipe connector 27 is pumped back to the urea tank through the backflow pump 24 and the backflow pipe connector 26. The flow channel block 29 is arranged between the liquid inlet connector 28 and the liquid inlet of the main pump 22, and the urea solution in the flow channel block is basically under no pressure, and the sealing performance requirement is relatively low. The internal flow channel of the middle shell 21 is simplified through the flow channel block 29, thereby improving the manufacturing feasibility of the middle shell 21 and reducing the production cost. Preferably, the main pump 22 can be a diaphragm metering pump, which includes a driving assembly, a pump body and a pump head, and a diaphragm assembly is arranged between the pump body and the pump head. Considering that the urea pump has a very high sealing performance requirement, in order to ensure the sealing performance, a diaphragm sheet of the diaphragm assembly is pressed to form a primary seal between the pump body and the pump head, and then a sealing ring is arranged at the connection position of the pump body and the pump head to form a secondary seal. The pump body and the pump cover of the backflow pump are also sealed by two sealing rings to form a secondary seal. In addition, in order to avoid contact and friction between the wire harness of the driving assembly and the middle shell 21, the wire harness is fixed in the middle shell 21 through a wire clamp made of PA material.

[0023] In another technical solution, the middle shell 21 is provided with a heating sheet 25 corresponding to the flow channel block 29. The heating sheet 25 is used to heat the area where the flow channel block 29 is located in the middle shell 21, so as to thaw the frozen urea solution. As one of the implementation manners, the heating sheet 29 is mainly composed of a first layer of aluminum foil, a heating wire, a second layer of aluminum foil and thermal insulation cotton stacked together, and the shape thereof can be determined according to the surface to be pasted actually, so as to ensure that the heating sheet can be pasted on the surface to be heated.

[0024] In another technical solution, as shown in Figure 4 As shown, the main pump 22 and the backflow pump 24 each include a pump body 223 and a driving assembly 221, the pump body 223 and the driving assembly 221 are connected as a whole through a buckle 222, and then the whole is directly installed in the middle shell 21 through bolts, so as to facilitate production and assembly and improve the production rhythm.

[0025] In another technical solution, the inlet of the main pump 22 is provided with an axial seal, and the outlet is provided with a radial seal. Since the pressure of the inlet is small, and the pressure of the outlet is high, the seal at the connection between the inlet and the external structure is designed as an axial seal, and the seal at the connection between the outlet and the external structure is designed as a radial seal. The radial seal can not only meet the sealing requirement, but also play a certain positioning role, which is beneficial to the installation of the main pump 22. If both seals are designed as radial seals, the manufacturing precision of the pump body is higher, the installation resistance of the pump body is large, or the pump body cannot be inserted. If both seals are designed as flat seals, leakage may occur due to the high pressure of the outlet, and additional positioning structure needs to be added.

[0026] In another technical solution, a connector is arranged on the PCBA board, a sealing gasket is arranged at the connection between the connector and the upper cover, and a screw mounting hole is arranged on the PCBA board corresponding to the outer periphery of the sealing gasket. When the PCBA board is installed, the screw is screwed into the screw mounting hole to connect with the upper cover. The screw is arranged near the sealing gasket, so that the sealing gasket can be better compressed, and the sealing performance is better.

[0027] In another technical solution, the lower cover assembly 30 comprises a lower cover 31 arranged at the bottom of the middle shell 21 and a lower sealing gasket 32 arranged at the connection between the lower cover 31 and the middle shell 21.

[0028] In another technical solution, a pressure sensor 23 is arranged between the outlet of the main pump 22 and the injection pipe joint, and the pressure of the outlet of the main pump 22 is monitored through the pressure sensor 23, so as to ensure the stability of the urea solution injection pressure. Preferably, an inlet filter screen is arranged at the inlet of the main pump, and a main filter core is arranged at the outlet.

[0029] Although the embodiments of the present application have been disclosed as above, they are not limited to the application and implementation listed in the specification and embodiments, and can be fully applied to various fields suitable for the present application. For those skilled in the art, other modifications can be easily realized, and therefore the present application is not limited to specific details and the figures shown and described herein.

Claims

1. A split urea pump, characterized by The device comprises an upper cover assembly, a middle housing assembly and a lower cover assembly which are detachably connected in sequence from top to bottom; the upper cover assembly comprises an upper cover and a PCBA board installed on the side of the upper cover facing the middle housing assembly; the middle housing assembly comprises a middle housing and a main pump, a backflow pump and a flow channel block installed in the middle housing; the middle housing is provided with a liquid inlet connector, a backflow connector and a jet connector respectively; the liquid inlet connector is in communication with the liquid inlet of the main pump, the liquid outlet of the main pump is in communication with the jet connector; the backflow connector is in communication with the liquid outlet of the backflow pump, the liquid inlet of the backflow pump is in communication with the liquid outlet of the main pump; the flow channel block is arranged between the liquid inlet of the main pump and the liquid inlet connector; the liquid inlet and the liquid outlet of the main pump are both provided with sealing elements.

2. The split case urea pump of claim 1, wherein, The middle housing is provided with a heating sheet corresponding to the flow channel block.

3. The split case urea pump of claim 1, wherein, The main pump and the backflow pump both comprise a pump body and a driving assembly, and the pump body and the driving assembly are connected as a whole through buckling.

4. The split case urea pump of claim 1, wherein, The liquid inlet of the main pump is provided with an axial sealing element, and the liquid outlet is provided with a radial sealing element.

5. The split case urea pump of claim 1 wherein, The PCBA board is provided with a connector, the connector is provided with a sealing gasket at the connection with the upper cover, and the PCBA board is provided with a screw mounting hole corresponding to the outer periphery of the sealing gasket.

6. The split case urea pump of claim 1, wherein, The lower cover assembly comprises a lower cover arranged at the bottom of the middle housing and a lower sealing gasket arranged at the connection between the lower cover and the middle housing.

7. The split case urea pump of claim 1 wherein, A pressure sensor is arranged between the liquid outlet of the main pump and the jet connector.

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