Urea nozzle and working machine comprising same

Abstract

The utility model relates to a urea nozzle and an operation machine comprising the same. The urea nozzle comprises a nozzle body (1), a filtering device (2) and a cleaning device (3), wherein the filtering device (2) and the cleaning device (3) are arranged on the radial outer side of the nozzle body (1). The nozzle body (1) defines a jet chamber and a jet orifice communicating with the jet chamber. A vent hole (11) communicated with the spraying cavity is formed in the side wall of the nozzle body (1). And the filtering device (2) is configured to filter impurities in the air entering the vent hole (11). The cleaning device (3) is configured to remove impurities accumulated on the filtering device (2). According to the urea nozzle, the filtering device and the cleaning device are arranged on the radial outer side of the nozzle main body, so that impurities in air are prevented from entering the nozzle main body during a urea suck-back emptying period, and the filtering device can be conveniently cleaned.

Description

Technical Field

[0001] The utility model relates to the technical field of engine exhaust aftertreatment, in particular to a urea nozzle and a working machine including the urea nozzle. Background Art

[0002] To meet the requirements of increasingly strict emission regulations, machines or vehicles powered by diesel engines are usually equipped with an SCR (Selective Catalytic Reduction) system. The SCR system reduces nitrogen oxides (NOx) in the engine exhaust to nitrogen (N 2 ) and water by injecting ammonia, urea or other nitrogen-containing compounds into the engine exhaust. The SCR system usually uses a urea aqueous solution with a concentration of 32.5% as a reducing agent, and mainly includes a urea tank, a urea pump and a urea nozzle. To avoid blockage of the urea nozzle caused by urea crystallization after the engine stops, the SCR system can perform a urea back-suction emptying operation, and the urea solution remaining in the urea nozzle and the connecting pipe between the urea pump and the urea nozzle flows back into the urea tank through the back-suction of the urea pump.

[0003] Traditional urea nozzles need to open the injection port during the urea back-suction emptying period to allow the engine exhaust to rush into the interior of the urea nozzle under the action of the pressure difference, and then bring the remaining urea solution back into the urea tank. Impurities in the engine exhaust will accumulate in the urea injection channel and inside the urea nozzle, causing blockage. Moreover, due to the high temperature of the engine exhaust, higher requirements are imposed on the materials of the valve core and electromagnetic coil in the urea nozzle.

[0004] In the prior art, a urea nozzle is known in which an air passage is formed on the side wall of the nozzle body, and a one-way valve is provided in the air passage. The one-way valve prevents the urea solution in the nozzle cavity from flowing out through the air passage and allows external air to enter the nozzle cavity during the urea back-suction emptying period. To prevent impurities in the air from entering the urea nozzle and causing blockage or contamination of the urea, an air filter is also provided in the air passage. However, especially for working machines such as excavators, bulldozers, loaders, rollers, etc. that are usually in a harsh working environment, there are more dust and impurities in the air, resulting in easy blockage of the air filter. Therefore, it is necessary to frequently remove the air filter for cleaning, which is time-consuming and laborious. Summary of the Utility Model

[0005] The purpose of the utility model is to solve at least one of the above problems and / or other problems existing in the prior art.

[0006] To achieve the above object, according to one aspect of the utility model, a urea nozzle is provided, the urea nozzle comprising a nozzle body, a filter device and a cleaning device. The nozzle body defines an injection cavity and an injection port connected to the injection cavity. A vent hole connected to the injection cavity is formed on the side wall of the nozzle body. The filter device and the cleaning device are arranged on the radial outer side of the nozzle body. The filter device is configured to filter impurities in the air entering the vent hole. The cleaning device is configured to remove impurities accumulated on the filter device.

[0007] According to one embodiment of the utility model, the filtering device comprises a cylinder and a filter screen. The first end of the cylinder is fixedly connected to the nozzle body. The second end of the cylinder is movably connected to the first end of the filter screen. The second end of the filter screen is movably connected to the nozzle body.

[0008] According to one embodiment of the utility model, one of the second end of the cylinder and the first end of the filter is provided with an annular groove, and the other of the second end of the cylinder and the first end of the filter is provided with a limiting ring matched with the annular groove.

[0009] According to an embodiment of the present utility model, a flexible covering piece is provided at the connection between the second end of the filter screen and the nozzle body.

[0010] According to an embodiment of the present utility model, the surface of the filter screen that is away from the nozzle body is configured as an inclined surface.

[0011] According to an embodiment of the present invention, an elastic member is provided between the filter screen and the nozzle body.

[0012] According to an embodiment of the utility model, the cleaning device comprises a striking block disposed on the inner wall of the filter screen, a circular ring rotatably disposed on the side wall of the nozzle body, and a striking block disposed on the circular ring. The striking block hits the striking block during the rotation of the circular ring to vibrate the filter screen.

[0013] According to one embodiment of the utility model, the cleaning device further comprises a motor disposed on the side wall of the nozzle body, a gear disposed on the output shaft of the motor, and a gear ring meshing with the gear and coaxially fixed with the circular ring.

[0014] According to one embodiment of the utility model, the nozzle body is provided with a plurality of first limit blocks and a plurality of second limit blocks at intervals along the circumferential direction, and the annular ring and the gear ring are arranged side by side between the plurality of first limit blocks and the plurality of second limit blocks along the axial direction of the nozzle body.

[0015] According to another aspect of the present utility model, there is provided a work machine, which includes a urea injection system. The urea injection system includes the urea nozzle as described above, and the urea nozzle is connected to a urea tank for storing urea solution via a urea pump.

[0016] The urea nozzle of the present utility model is provided with a filtering device and a cleaning device on the radial outer side of the nozzle body, which avoids impurities in the air from entering the inside of the nozzle body during the urea back-suction and emptying process, and can conveniently clean the filtering device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The features and advantages of the present utility model will be clearly understood from the following detailed description provided with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and thus should not be considered as limiting the present utility model, where:

[0018] Figure 1 A perspective view showing a urea nozzle according to an exemplary embodiment of the present utility model;

[0019] Figure 2 Showing Figure 1 A partial cross-sectional view of the urea nozzle shown;

[0020] Figure 3 Showing Figure 1 A schematic view showing two parts of the filtering device of the urea nozzle shown in a separated state.

[0021] Description of the reference numerals:

[0022] 1. Nozzle body; 11. Vent hole; 12. First limit block; 13. Second limit block; 2. Filtering device; 21. Cylinder body; 22. Filter screen; 23. Annular groove; 24. Limit ring; 25. Flexible covering; 3. Cleaning device; 31. Struck block; 32. Ring; 33. Striking block; 34. Motor; 35. Gear; 36. Tooth ring; 4. Elastic member. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] Embodiments of the present utility model will be described below with reference to the accompanying drawings. In the following description, many specific details are set forth in order to enable those skilled in the art to more fully understand and implement the present utility model. However, it is obvious to those skilled in the art that some of these specific details may not be required for the implementation of the present utility model. In addition, it should be understood that the present utility model is not limited to the specific embodiments described. On the contrary, the present utility model can be implemented by any combination of the following features and elements, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are for illustrative purposes only and should not be regarded as elements or limitations of the claims, unless expressly stated in the claims.

[0024] In the following text, terms such as "first", "second", etc. are used to describe the elements of the present application. These terms are only used to distinguish each element, rather than to limit the nature, order or number of these elements. The terms "comprising" and "having" are used to indicate an open inclusion meaning, and mean that there may be additional elements / components in addition to the listed elements / components.

[0025] Figures 1 to 3 A urea nozzle according to an embodiment of the present utility model is shown. As shown in the figure, the urea nozzle according to this embodiment may include a nozzle body 1, a filtering device 2 and a cleaning device 3.

[0026] The nozzle body 1 defines an injection chamber and an injection port (not shown) communicating with the injection chamber. The urea solution from the urea tank can be transported to the injection chamber through the urea pump via the urea inlet. The injection port may be formed at the lower end of the nozzle body 1 in Figure 1 and the urea inlet may be formed at the upper end of the nozzle body 1 in Figure 1 Inside the nozzle body 1, a valve core, an electromagnetic coil, a spring, etc. may also be provided. The spring is configured to push the valve core to close the injection port. The electromagnetic coil is configured to actuate the valve core to open the injection port when energized, so as to achieve timed and quantitative injection of the urea solution into the engine exhaust pipe. These contents are well known to those skilled in the art, and their detailed descriptions are omitted here.

[0027] An air vent 11 communicating with the injection chamber is formed on the side wall of the nozzle body 1, as shown in Figure 2 and Figure 3 The number of the air vents 11 may be one, or two, three or more. For example, a plurality of air vents 11 may be distributed substantially evenly along the circumferential direction of the nozzle body 1. A check valve (not shown) may be provided in the air vent 11, and the check valve is configured to allow the outside air to enter the injection chamber through the air vent 11 and prohibit the fluid in the injection chamber from flowing out of the nozzle body 1 through the air vent 11. When performing the urea back-suction emptying operation after the engine stops, the injection port is closed, and the outside air can enter the injection chamber through the air vent 11 to empty the urea solution in the injection chamber and inhibit the nozzle blockage problem caused by urea crystallization.

[0028] The filtering device 2 is arranged on the radial outer side of the injection body 1 and is configured to filter impurities in the air entering the air vent 11. The cleaning device 3 is arranged between the filtering device 2 and the nozzle body 1 in the radial direction of the injection body 1 and is configured to remove the impurities accumulated on the filtering device 2.

[0029] Specifically, referring to Figure 2 and Figure 3As shown, the filtering device 2 may include a cylinder body 21 and a filter screen 22. The first end (the lower end in the figure) of the cylinder body 21 is fixedly connected to the nozzle body 1, so that the cross-section of the cylinder body 21 is L-shaped. That is, the cylinder body 21 may include a first section extending along the axial direction of the nozzle body 1 and having a certain gap with the nozzle body 1, and a second section extending along the radial direction of the nozzle body 1. The radially inner end of the second section may be fixedly connected to the outer wall of the nozzle body 1 by welding, for example. The second end (the upper end in the figure) of the cylinder body 21 is movably connected to the first end (the lower end in the figure) of the filter screen 22. The second end (the upper end in the figure) of the filter screen 22 is movably connected to the nozzle body 1.

[0030] In this embodiment, an upwardly open annular groove 23 is provided at the second end of the cylinder body 21, and a limiting ring 24 is provided at the first end of the filter screen 22. The limiting ring 24 can be inserted into the annular groove 23. The limiting ring 24 can be made of stainless steel material. The cross-sectional width of the annular groove 23 can be slightly larger than the cross-sectional thickness of the limiting ring 24. Those skilled in the art can understand that an annular groove with a downward opening can also be provided at the first end of the filter screen 22, and a corresponding limiting ring can be provided at the second end of the cylinder body 21.

[0031] As Figure 2 and Figure 3 shown, a flexible covering member 25 may be provided at the connection between the second end of the filter screen 22 and the nozzle body 1. The flexible covering member 25 can be a waterproof canvas, one end of which is connected to the nozzle body 1 and the other end is connected to the second end of the filter screen 22.

[0032] The filter screen 22 is arranged obliquely with respect to the nozzle body 1. In particular, the surface of the filter screen 22 on the side facing away from the nozzle body 1 is set as an inclined surface.

[0033] An elastic member 4, such as a telescopic spring, etc., may be provided between the filter screen 22 and the nozzle body 1. One end of the elastic member 4 is connected to the inner wall of the filter screen 22, and the other end is connected to the outer wall of the nozzle body 1.

[0034] The cleaning device 3 in this embodiment includes a struck block 31, a ring 32 and a striking block 33, as Figure 2 and Figure 3 shown. The struck block 31 is connected to the inner wall of the filter screen 22. The ring 32 is rotatably arranged on the side wall of the nozzle body 1. The striking block 33 is connected to the ring 3. During the rotation of the ring 32, the striking block 33 can strike the struck block 31 to vibrate the filter screen 22. Although not shown in the figure, those skilled in the art can understand that the struck block 31 has an inclined struck surface.

[0035] The number of the struck blocks 31 and the striking blocks 33 may be one or more. In addition, the number of the struck blocks 31 and the striking blocks 33 may be the same or different. For example, three struck blocks 31 may be arranged circumferentially and substantially evenly on the inner wall of the filter screen 22, while one striking block 33 is arranged on the outer wall of the nozzle body 1. During the rotation of the ring 32, the striking block 33 can sequentially strike the three struck blocks 31. Alternatively, one struck block 31 may be arranged on the inner wall of the filter screen 22, while three striking blocks 33 are arranged circumferentially and substantially evenly on the outer wall of the nozzle body 1. During the rotation of the ring 32, the three striking blocks 33 can sequentially strike the struck block 31.

[0036] The cleaning device 3 in this embodiment further includes a motor 34, a gear 35 and a gear ring 36. The motor 34 is arranged on the side wall of the nozzle body 1. The gear 35 is arranged on the output shaft of the motor 34 to rotate with the output shaft when the motor 34 operates. On the one hand, the gear ring 36 meshes with the gear 35, and on the other hand, it is fixedly arranged together with the ring 32 side by side along the axial direction of the nozzle body 1. Thus, when the output shaft of the motor 34 drives the gear 35 to rotate, the gear 35 drives the gear ring 36 and then drives the ring 32 to rotate circumferentially along the nozzle body 1.

[0037] Continue to refer to Figure 2 , a plurality of first limit blocks 12 and a plurality of second limit blocks 13 are arranged on the nozzle body 1 at circumferential intervals. Figure 3 The illustrations of the first limit blocks 12 and the second limit blocks 13 are omitted in

[0038] The present utility model also provides a working machine including a urea injection system. The urea injection system may include a urea tank, a urea pump and the urea nozzle as described above. The urea nozzle is connected to the urea tank for storing urea solution via the urea pump.

[0039] Industrial applicability

[0040] The urea nozzle according to the present utility model is particularly applicable to working machines with diesel engines, especially excavators, bulldozers, loaders, rollers, etc. in harsh working environments. However, it should be understood that the urea nozzle according to the present utility model can also be applied to other devices with SCR systems, such as motor vehicles or diesel generator sets using diesel engines as power sources.

[0041] The following combines with Figures 1 to 3The illustrated embodiment briefly illustrates the working process and effect of the urea nozzle according to the utility model during urea back suction and emptying.

[0042] When the running diesel engine stops, the electronic control unit gives a backdraft emptying command. In response to the command, the electromagnetic coil in the urea injection system is de-energized, the spring pushes the valve core against the valve seat to close the injection port on the nozzle body 1, and the urea pump backdrafts to pump the urea solution back into the urea tank. During the urea backdraft emptying, the outside air enters the vent 11 on the nozzle body 1 through the filter 22, and enters the injection chamber inside the nozzle body 1 through the vent 11. The filter 22 filters impurities in the air to prevent impurities from entering the urea nozzle and causing blockage or contamination of urea.

[0043] In order to prevent a large amount of impurities from accumulating on the filter 22 and thus affecting the efficiency of air entering the nozzle body 1, the motor 34 can be started periodically, for example, to drive the gear ring 36 and the ring 32 to rotate relative to the nozzle body 1 via the gear 35. During the rotation of the ring 32, the striking block 33 on the ring 32 hits the struck block 31 on the inner wall of the filter 22, thereby causing the filter 22 to vibrate, thereby shaking off the impurities accumulated on the filter 22. It can be understood that the cleaning process of the filter 22 can be performed during the urea back suction and emptying period, and can also be performed during the period other than the urea back suction and emptying period.

[0044] When the filter 22 is vibrated and cleaned, the stop ring 24 can shake in the annular groove 23. This movable connection between the filter 22 and the cylinder 5 can not only ensure that the cylinder supports the filter 22 and prevents the filter 22 from slipping off the cylinder 5, but also provide a certain degree of freedom for the vibration of the filter 22. The stop ring 24 made of stainless steel has better strength, which is conducive to the long-term use of the stop ring 24.

[0045] The flexible cover 25 between the upper end of the filter screen 22 and the nozzle body 1 can prevent foreign matter shaken off during the filter screen vibration cleaning from entering the space between the filter screen 22 and the nozzle body 1 .

[0046] The surface of the filter screen 22 that is away from the nozzle body 1 is arranged as an inclined surface, so that impurities can slide down along the inclined surface when the filter screen 22 is shaken.

[0047] The elastic member 4 between the filter screen 22 and the nozzle body 1 facilitates the resetting of the filter screen 22 during vibration cleaning.

[0048] The first limiting block 12 and the second limiting block 13 on the nozzle body 1 can limit the annular ring 3 and the gear ring 2, so that the rotation process of the annular ring 3 and the gear ring 2 is more stable.

[0049] As described above, the urea nozzle according to the present utility model is provided with a filtering device 2 and a cleaning device 3 on the radial outer side of the nozzle body 1, avoiding impurities in the air from entering the inside of the nozzle body 1 during the urea back suction and emptying. Moreover, compared with the air filter disposed in the side wall of the nozzle body 1 in the prior art, the filtering device 2 can be conveniently cleaned by the cleaning device 3 without the cumbersome work of removing the air filter from the nozzle body 1.

[0050] For those skilled in the art, various modifications and variations can be made to the embodiments disclosed above without departing from the scope or spirit of the present utility model. Based on the practice of the present utility model disclosed in this specification, other embodiments of the present utility model will be apparent to those skilled in the art. This specification and the examples disclosed therein should be considered illustrative only, and the true scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A urea nozzle, comprising a nozzle body (1), wherein the nozzle body (1) defines an injection cavity and an injection port communicating with the injection cavity, wherein: A vent hole (11) communicating with the injection chamber is formed on the side wall of the nozzle body (1), and a filter device (2) and a cleaning device (3) are arranged radially outside the nozzle body (1), wherein the filter device (2) is configured to filter impurities in the air entering the vent hole (11), and the cleaning device (3) is configured to remove impurities accumulated on the filter device (2).

2. The urea nozzle according to claim 1, characterized in that: The filtering device (2) comprises a barrel (21) and a filter screen (22); the first end of the barrel (21) is fixedly connected to the nozzle body (1); the second end of the barrel (21) is movably connected to the first end of the filter screen (22); and the second end of the filter screen (22) is movably connected to the nozzle body (1).

3. The urea nozzle according to claim 2, characterized in that: One of the second end of the cylinder (21) and the first end of the filter screen (22) is provided with an annular groove (23), and the other of the second end of the cylinder (21) and the first end of the filter screen (22) is provided with a limiting ring (24) adapted to the annular groove (23).

4. The urea nozzle according to claim 2, characterized in that: A flexible covering piece (25) is provided at the connection between the second end of the filter screen (22) and the nozzle body (1).

5. The urea nozzle according to any one of claims 2 to 4, characterized in that: The surface of the filter screen (22) that faces away from the nozzle body (1) is arranged as an inclined surface.

6. The urea nozzle according to any one of claims 2 to 4, characterized in that: An elastic member (4) is provided between the filter screen (22) and the nozzle body (1).

7. The urea nozzle according to any one of claims 2 to 4, characterized in that: The cleaning device (3) comprises a striking block (31) arranged on the inner wall of the filter screen (22), a circular ring (32) rotatably arranged on the side wall of the nozzle body (1), and a striking block (33) arranged on the circular ring (32), wherein the striking block (33) strikes the striking block (31) during the rotation of the circular ring (32) to cause the filter screen (22) to vibrate.

8. The urea nozzle according to claim 7, characterized in that: The cleaning device (3) further comprises a motor (34) arranged on the side wall of the nozzle body (1), a gear (35) arranged on the output shaft of the motor (34), and a gear ring (36) meshing with the gear (35) and coaxially fixed with the ring (32).

9. The urea nozzle according to claim 8, characterized in that: The nozzle body (1) is provided with a plurality of first limit blocks (12) and a plurality of second limit blocks (13) at intervals along the circumferential direction, and the annular ring (32) and the gear ring (36) are arranged side by side between the plurality of first limit blocks (12) and the plurality of second limit blocks (13) along the axial direction of the nozzle body (1).

10. A working machine, comprising a urea injection system, characterized in that: The urea injection system comprises a urea nozzle according to any one of claims 1 to 9, wherein the urea nozzle is connected to a urea tank for storing a urea solution via a urea pump.

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