Sunken nut seat, SCR (Selective Catalytic Reduction) treatment unit, post-treatment assembly and vehicle

Abstract

The utility model provides a sinking type nut seat, SCR processing unit, post-processing assembly and vehicle relates to vehicle field, sinking type nut seat includes nut seat body, the middle part of nut seat body is equipped with the through hole that is coaxial with nut seat body, the through hole is equipped with the internal thread, and the internal thread is equipped with the internal thread. The nut seat comprises a nut seat body, a seating platform protruding out of the nut seat body is arranged on the peripheral face of the nut seat body, the first face of the seating platform is flush with the first face of the nut seat body, the second face of the seating platform is a plane, and the distance between the second face of the seating platform and the second face of the nut seat body is larger than the height of the seating platform. The measuring accuracy of the sensor can be improved.

Description

Technical Field

[0001] The utility model relates to the field of vehicles, and in particular to a sunken nut seat, an SCR processing unit, a post-processing assembly and a vehicle. Background Art

[0002] The post-processing device of a diesel engine mainly includes a DOC (diesel oxidation catalyst), a DPF (diesel particulate filter) and an SCR (selective catalytic reduction) processing unit. On the post-processing device, multiple sensors (such as temperature sensors, differential pressure sensors, nitrogen oxide sensors, etc.) need to be installed for signal acquisition. In the prior art, a corresponding opening is usually opened at the position where the sensor needs to be installed in the post-processing device, and a nut seat is welded at the opening, and the sensor is installed and fixed by relying on the nut seat.

[0003] However, the installed sensor may affect the measurement accuracy of the sensor due to the shallow position of the probe. For example, for temperature sensors, due to the temperature gradient inside the device, the temperature at different places is not completely consistent. The temperature near the surface of the device may be slightly lower than the temperature inside the device. If the sensor probe is shallow, it cannot accurately reflect the internal temperature. For differential pressure sensors, since the flow of gas in the exhaust pipe is not uniform, the flow rate near the edge of the pipe is low. If the sensor probe is shallow, it is difficult to accurately reflect the pressure in the pipe. For nitrogen oxygen sensors, if the sensor probe is shallow, the NOx content of the internal gas cannot be accurately measured. Since the sensor in the prior art is a general product with a fixed structure and the length of the probe cannot be extended, it is difficult to improve the measurement accuracy of the sensor by changing the sensor structure. Utility Model Content

[0004] In order to solve the deficiencies of the prior art, the purpose of the utility model is to provide a sunken nut seat, an SCR processing unit, a post-processing assembly and a vehicle, so as to improve the measurement accuracy of the sensor by improving the structure of the nut seat for fixing the sensor.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the utility model provides a sunken nut seat, including a nut seat body, a through hole coaxial with the nut seat body is opened in the middle of the nut seat body, an internal thread is arranged in the through hole, the outer peripheral surface of the nut seat body has a seating platform protruding from the nut seat body, the first surface of the seating platform is flush with the first surface of the nut seat body, the second surface of the seating platform is a plane, and the distance between the second surface of the seating platform and the second surface of the nut seat body is greater than the height of the seating platform.

[0006] Preferably, the through hole includes a first connecting hole and a second connecting hole which are interconnected, the first connecting hole is opened on the first surface of the nut seat body, the second connecting hole is opened on the second surface of the nut seat body, and the aperture of the first connecting hole is larger than the aperture of the second connecting hole.

[0007] Preferably, the inner wall of the first connecting hole is provided with an internal thread.

[0008] Preferably, a urea catalytic hydrolysis coating is provided on the surface of the nut seat body.

[0009] Preferably, a backing groove is provided between the first connecting hole and the second connecting hole.

[0010] Preferably, a chamfer is provided between the second surface and the outer peripheral surface of the nut seat body.

[0011] The second aspect of the utility model provides an SCR processing unit, including an SCR housing, a sensor and a sunken nut seat provided by the first aspect above, wherein the SCR housing is provided with a mounting hole for mounting the sensor, the second surface of the seating platform of the sunken nut seat is in contact with and fixedly connected to the outer surface of the SCR housing, the aperture of the mounting hole is equal to the outer diameter of the second surface of the nut seat body of the sunken nut seat, and the sensor is fixed to the SCR housing through the sunken nut seat.

[0012] Preferably, the number of the sensors, the number of the mounting holes and the number of the sunken nut seats are equal, and the sensors include temperature sensors, differential pressure sensors and / or nitrogen oxide sensors.

[0013] The third aspect of the utility model provides a post-processing assembly, including a post-processing assembly housing, a sensor and a sunken nut seat provided in the first aspect above, the post-processing assembly housing is provided with a mounting hole for installing the sensor, the second surface of the seating platform of the sunken nut seat is in contact with and fixedly connected to the outer surface of the post-processing assembly housing, the aperture of the mounting hole is equal to the outer diameter of the second surface of the nut seat body of the sunken nut seat, and the sensor is fixed to the post-processing assembly housing through the sunken nut seat.

[0014] A fourth aspect of the present invention provides a vehicle, comprising an SCR processing unit provided by the second aspect, or a post-processing assembly provided by the third aspect.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] 1. The utility model provides a sunken nut seat, an SCR processing unit, a post-processing assembly and a vehicle. By improving the structure of the nut seat, a seating platform close to the first surface of the nut seat is arranged on the outer side of the nut seat, and the nut seat is improved to a sunken installation method, thereby realizing the upward movement of the welding position. The nut seat after installation sinks as a whole, thereby realizing the downward movement of the sensor position, increasing the insertion depth of the sensor probe, and thus improving the measurement accuracy of the sensor; in addition, the downward movement of the sensor position can also reduce the height of the sensor located at the outer side of the shell, increase the distance between the sensor and other structures, make the disassembly and assembly of the sensor more convenient, and at the same time create conditions for further reducing the overall volume of the assembly and optimizing the positional relationship of the components in the assembly.

[0017] 2. The utility model does not need to improve other structures in the prior art. The improved sunken nut seat can directly utilize the hole position of the original mounting hole; the surface of the nut seat body is also sprayed with a urea catalytic hydrolysis coating. The sunken nut seat body after installation can effectively avoid the common urea crystallization problem in the post-treatment system, and overcomes the problem that urea crystals may cover the sensor probe after long-term use of the sensor, causing the sensor to fail and unable to achieve monitoring.

[0018] Advantages of additional aspects of the present invention will be partially given in the following description, and partially become apparent from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0020] Figure 1 It is a schematic diagram of the installation of a nut seat in the prior art;

[0021] Figure 2 It is a schematic diagram of the installation position of the sensor in the prior art;

[0022] Figure 3 This is a schematic diagram of the installation of the sunken nut seat of the utility model;

[0023] Figure 4 This is a schematic diagram of the installation position of the sensor of the utility model;

[0024] Figure 5 It is a schematic diagram of the overall structure of the sunken nut seat;

[0025] Figure 6 It is a cross-sectional view of a sunken nut seat;

[0026] Figure 7Schematic diagram of sensor and assembly installation and disassembly;

[0027] Figure 8 This is a schematic diagram of the sensor and assembly installation.

[0028] Among them, 1. nut seat body; 2. seating platform; 3. first connecting hole; 4. second connecting hole; 5. tool withdrawal groove; 6. sensor; 7. post-processing assembly; 8. sunken nut seat; 9. mounting hole. DETAILED DESCRIPTION

[0029] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0030] Embodiment 1

[0031] like Figure 3-Figure 6 As shown, a sunken nut seat includes a nut seat body 1, a through hole coaxial with the nut seat body 1 is opened in the middle of the nut seat body 1, and an internal thread for connecting a sensor is arranged in the through hole. The outer peripheral surface of the nut seat body 1 has a seating platform 2 protruding from the nut seat body 1, the first surface of the seating platform 2 is flush with the first surface of the nut seat body 1, the second surface of the seating platform 2 is a plane, and the distance between the second surface of the seating platform 2 and the second surface of the nut seat body 1 is greater than the height of the seating platform 2.

[0032] In the prior art, the post-treatment device of National VI / Euro VI diesel engine generally adopts CH injection

[0033] +DOC+DPF+SCR technical route. The DOC, DPF and SCR processing units can be connected separately; they can also be integrated together, and the sensors and other components of each functional unit are integrated at the same time, and installed in the form of an assembly. Multiple sensors need to be installed on the post-processing device for signal acquisition. Usually, mounting holes are opened at the positions where the sensors need to be installed, and then nut seats are welded on the mounting holes, and the sensors are installed and fixed with the help of the nut seats.

[0034] The installation position of the sensor will affect the measurement accuracy. If the sensor probe is shallow, it may not be able to accurately obtain the most realistic measurement, which will affect the ECU's control of the urea injection amount and the vehicle's post-processing effect. Since the sensor is a universal specification with a fixed structure, if the sensor structure is changed, the production and processing cost and process complexity will be greatly increased, which does not meet the requirements of industrial production. Therefore, it is necessary to improve the measurement accuracy of the sensor by making the smallest possible changes.

[0035] In the prior art, there are two main types of nut seats used to fix sensors: a cylindrical nut seat and a nut seat with a protrusion at one end. Figure 1The figure shows a schematic diagram of a nut seat with a protrusion at one end in the prior art. Compared with the overall cylindrical shape, this nut seat has a protrusion at the bottom that is consistent with the diameter of the mounting hole, so as to facilitate the cooperation with the mounting hole. When in use, the protrusion is directly inserted into the mounting hole, and the nut seat and the mounting hole can be easily aligned, and the two are welded together, and then the sensor is screwed into the nut seat to achieve the fixation of the sensor. Figure 2 shown.

[0036] Based on the existing nut seat, this embodiment further improves the structure of the nut seat and designs the nut seat to be installed in a sunken manner, so that it not only has the function of aligning with the mounting hole, but also can reduce the installation height of the sensor and increase the depth of the sensor probe, thereby improving the measurement accuracy of the sensor.

[0037] like Figure 3 As shown, in the sunken nut seat provided in this embodiment, the seating platform is arranged on the upper part of the nut seat body, so that the nut seat body can be sunk into the post-processing assembly during installation. Figure 2 and Figure 4 It can be seen that after the nut seat body sinks, the installation position of the sensor can also be moved down accordingly, thereby increasing the depth of the sensor probe. Since only the external structure of the nut seat body is changed without changing other structures, the improved sunken nut seat can directly replace the original nut seat, improving the measurement accuracy without changing the overall structure or adding additional assembly processes.

[0038] For ease of description, Figure 6 The upper surface of the nut seat body is used as the first surface of the nut seat body, and the lower surface is used as the second surface of the nut seat body; the upper surface of the seating platform is used as the first surface of the seating platform, and the lower surface is used as the second surface of the seating platform. The distance between the first surface and the second surface of the seating platform is used as the height of the seating platform. Figure 3-Figure 6As shown, the seating platform 2 is arranged on the first surface of the nut seat body 1, and the first surface of the seating platform is flush with the first surface of the nut seat body, and together form a sealing platform for the sensor; the second surface of the seating platform is a plane, which is used to align and weld with the shell at the mounting hole during installation. The through hole in the middle of the nut seat body 1 includes a first connecting hole 3 and a second connecting hole 4 that are interconnected. The first connecting hole 3 is opened on the first surface of the nut seat body 1, and the inner wall is provided with an internal thread; the second connecting hole 4 is opened on the second surface of the nut seat body 1, and the aperture of the first connecting hole 3 is larger than the aperture of the second connecting hole 4. In order to facilitate the withdrawal of the tool during processing, a tool withdrawal groove 5 is provided between the first connecting hole 3 and the second connecting hole 4. During installation, the sensor is screwed in from the first connecting hole 3, and the sensor probe passes through the second connecting hole and extends into the shell. In order to remove edge burrs, facilitate the nut seat body to enter the mounting hole, and disperse thermal stress, a chamfer is provided between the second surface and the outer peripheral surface of the nut seat body 1.

[0039] In addition, in some embodiments, a urea catalytic hydrolysis coating is sprayed on the surface of the nut seat body. SCR technology is one of the main post-treatment technologies for eliminating nitrogen oxides in diesel engine exhaust. By spraying a mist of urea aqueous solution into the exhaust tail pipe, it undergoes hydrolysis and pyrolysis reactions with high-temperature exhaust gas to generate ammonia, which then selectively reduces nitrogen oxides NOx to nitrogen under the action of a catalyst, thereby achieving the elimination of nitrogen oxides in the exhaust gas. However, in the actual operation process, incompletely reacted urea is easy to crystallize. When the urea crystals cover the sensor probe, it will affect the measurement of the sensor. Since the sinking nut seat in this embodiment is a sinking design, the nut seat body sinks into the assembly. Therefore, a layer of urea catalytic hydrolysis coating can be sprayed on the surface of the nut seat body, so that the nearby unpyrolyzed urea can be hydrolyzed to avoid urea crystals covering the sensor probe and causing sensor failure. The composition of the urea catalytic hydrolysis coating is a catalyst that can catalyze the hydrolysis of urea, which can be a tungsten carbide coating or other dehydrogenation catalyst coating.

[0040] Embodiment 2

[0041] Based on the first embodiment, this embodiment further provides an SCR processing unit, including an SCR housing, a sensor and the sunken nut seat provided in the first embodiment. The SCR housing is provided with a mounting hole for mounting the sensor, the second surface of the seating platform of the sunken nut seat is in contact with and fixedly connected to the outer surface of the SCR housing, the aperture of the mounting hole is equal to the outer diameter of the second surface of the nut seat body of the sunken nut seat, and the sensor is fixed to the SCR housing through the sunken nut seat.

[0042] In this embodiment, the sunken nut seat is set on the SCR processing unit to fix the sensor on the SCR processing unit, so as to realize the position sinking of the sensor and improve the measurement accuracy of the sensor without changing the structure of the SCR processing unit itself. The number of sensors, the number of mounting holes and the number of sunken nut seats are equal. The inner diameter of the mounting hole is equal to the outer diameter of the nut seat body. When assembling, the nut seat is directly plugged into the mounting hole, and the seating platform is welded and fixed to the SCR shell, and then the sensor is screwed into the through hole of the nut seat.

[0043] The sensors installed on the SCR processing unit include temperature sensors, differential pressure sensors and nitrogen oxide sensors. You can choose whether to set the sensors to be installed in a sunken manner according to actual needs. The sunken sensors go deeper into the SCR processing unit and the external height is reduced, which can not only improve the measurement accuracy of the sensors, but also reduce the external space occupied by the sensors.

[0044] Embodiment 3

[0045] This embodiment further provides a post-processing assembly based on the first embodiment, such as Figure 7-Figure 8 As shown, it includes a post-processing assembly housing, a sensor 6 and a sunken nut seat 8 provided in the first embodiment. A mounting hole 9 for mounting the sensor 6 is provided on the post-processing assembly housing, the second surface of the seating platform of the sunken nut seat 8 is in contact with and fixedly connected to the outer surface of the post-processing assembly housing, the aperture of the mounting hole 9 is equal to the outer diameter of the second surface of the nut seat body of the sunken nut seat 8, and the sensor 6 is fixed to the post-processing assembly housing through the sunken nut seat 8.

[0046] For the method in which the DOC, DPF and SCR treatment units are integrated into one and set in the form of an assembly, the sensor 6 can also be installed on the post-treatment assembly 7 using a sunken nut seat 8. The implementation method is the same as that of Example 2. The mounting hole can directly use the existing hole position, and it is determined whether the sensor needs to be installed in a sunken manner according to actual needs. If the measurement accuracy can be improved after sinking, or the current installation form of the sensor may have problems such as difficulty in disassembly and assembly due to insufficient space or affect the layout of other components, the sensor can be installed using a sunken nut seat 8. For sensors where urea crystals may be produced, a urea catalytic hydrolysis coating can also be sprayed on the corresponding sunken nut seat.

[0047] Embodiment 4

[0048] This embodiment provides a vehicle, which may be a post-processing device connected in a split manner, including an SCR processing unit provided in Embodiment 2, or may be a post-processing device integrated into an assembly, including an post-processing assembly provided in Embodiment 3. The vehicle may be a passenger car, a commercial vehicle, a non-road mobile machine, or other vehicle powered by a diesel engine.

[0049] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A sunken nut seat, characterized in that: It includes a nut seat body, a through hole coaxial with the nut seat body is opened in the middle of the nut seat body, an internal thread is arranged in the through hole, the outer peripheral surface of the nut seat body has a seating platform protruding from the nut seat body, the first surface of the seating platform is flush with the first surface of the nut seat body, the second surface of the seating platform is a plane, and the distance between the second surface of the seating platform and the second surface of the nut seat body is greater than the height of the seating platform.

2. A sunken nut seat as claimed in claim 1, characterized in that: The through hole includes a first connecting hole and a second connecting hole which are interconnected. The first connecting hole is opened on the first surface of the nut seat body, and the second connecting hole is opened on the second surface of the nut seat body. The aperture of the first connecting hole is larger than the aperture of the second connecting hole.

3. A sunken nut seat as claimed in claim 2, characterized in that: The inner wall of the first connecting hole is provided with an internal thread.

4. A sunken nut seat as claimed in claim 1, characterized in that: The surface of the nut seat body is provided with a urea catalytic hydrolysis coating.

5. A sunken nut seat as claimed in claim 2, characterized in that: A cutter recess is provided between the first connection hole and the second connection hole.

6. A sunken nut seat as claimed in claim 1, characterized in that: A chamfer is arranged between the second surface and the outer peripheral surface of the nut seat body.

7. An SCR processing unit, characterized in that: It comprises an SCR housing, a sensor and a sunken nut seat as described in any one of claims 1 to 6, wherein a mounting hole for mounting the sensor is opened on the SCR housing, the second surface of the seating platform of the sunken nut seat is in contact with and fixedly connected to the outer surface of the SCR housing, the aperture of the mounting hole is equal to the outer diameter of the second surface of the nut seat body of the sunken nut seat, and the sensor is fixed to the SCR housing through the sunken nut seat.

8. The SCR processing unit according to claim 7, characterized in that: The number of the sensors, the number of the mounting holes and the number of the sunken nut seats are equal, and the sensors include temperature sensors, differential pressure sensors and / or nitrogen oxygen sensors.

9. A post-processing assembly, characterized in that: It includes a post-processing assembly housing, a sensor and a sunken nut seat as described in any one of claims 1 to 6, wherein a mounting hole for mounting the sensor is opened on the post-processing assembly housing, the second surface of the seating platform of the sunken nut seat is in contact with and fixedly connected to the outer surface of the post-processing assembly housing, the aperture of the mounting hole is equal to the outer diameter of the second surface of the nut seat body of the sunken nut seat, and the sensor is fixed to the post-processing assembly housing through the sunken nut seat.

10. A vehicle, characterized in that: It comprises an SCR treatment unit as described in any one of claims 7-8, or comprises an after-treatment assembly as described in claim 9.

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