Electric heater and exhaust gas aftertreatment device

Abstract

Disclosed in the present application is an electric heater, comprising a housing, a heating belt assembly, a first connecting block, a first electrode assembly and a second electrode assembly. The housing comprises a mounting space and a first mounting hole. The heating belt assembly is at least partially located in the mounting space. The first connecting block is connected to the heating belt assembly, and the first connecting block is provided with a first fixing hole. The first electrode assembly comprises a first electrode. The first electrode is provided with a first fixing portion. The first fixing portion passes through the first mounting hole and is connected to the first fixing hole in a threaded fit manner. The second electrode assembly comprises a second electrode, and the second electrode is directly or indirectly connected to the heating belt assembly. In this way, the present application avoids potential structural reliability issues that might be caused by directly welding the first electrode to the heating belt assembly, thereby improving durability. Further disclosed in the present application is an exhaust gas aftertreatment device comprising the electric heater.

Description

Electric heater and exhaust gas aftertreatment device

[0001] This application claims priority to Chinese Patent Application No. 202410986061.3, filed on July 22, 2024, entitled "Electric Heater and Exhaust Gas Aftertreatment Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to an electric heater and an exhaust gas aftertreatment device, belonging to the field of engine exhaust gas aftertreatment technology. Background Technology

[0003] Exhaust gas aftertreatment devices in related technologies typically include at least one exhaust gas aftertreatment component. The exhaust gas aftertreatment component includes a housing and an exhaust gas aftertreatment carrier encapsulated within the housing. The exhaust gas aftertreatment carrier has an operating temperature range; that is, the exhaust gas aftertreatment carrier achieves optimal operating efficiency only when the temperature reaches this operating temperature range.

[0004] With increasingly stringent emission regulations, higher and higher requirements are being placed on exhaust aftertreatment devices, especially during engine cold starts when the exhaust gas temperature is too low to reach the operating temperature of the aftertreatment system. In this situation, the aftertreatment system may not function or its conversion efficiency may be extremely low, easily leading to emissions pollution and other problems.

[0005] Therefore, how to minimize the time required to reach the operating temperature of the exhaust gas aftertreatment carrier is a technical problem faced by those skilled in the art.

[0006] An electric heater is a device that uses electrical energy to heat exhaust gas, thereby shortening the time it takes to reach the working temperature of the exhaust gas after-treatment carrier. It is one of the important technical means in the industry.

[0007] Electric heaters typically consist of a housing, a heating element, and electrodes. The electrodes are usually connected to the heating element by welding, but this connection method still has room for improvement.

[0008] Summary of the Invention

[0009] The purpose of this application is to provide a highly reliable electric heater and an exhaust gas aftertreatment device.

[0010] To achieve the above objectives, this application adopts the following technical solution: an electric heater configured for use in an exhaust gas aftertreatment device, the electric heater comprising:

[0011] The housing includes a mounting space, an outer surface, an inner surface opposite to the outer surface, and a first mounting hole penetrating the outer surface and the inner surface and communicating with the mounting space; a heating band assembly, at least partially located in the mounting space; a first connecting block connected to the heating band assembly, the first connecting block having a first fixing hole; a first electrode assembly including a first electrode, the first electrode having a first fixing part, the first fixing part passing through the first mounting hole and connected to the first fixing hole by a threaded engagement; a second electrode assembly including a second electrode, the second electrode being directly or indirectly connected to the heating band assembly; one of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0012] As a further improvement of this application, the first fixing hole is provided with an internal thread, and the first fixing part is provided with an external thread, wherein the internal thread and the external thread are engaged.

[0013] As a further improvement to the technical solution of this application, the first electrode assembly further includes a first insulating portion disposed on the first electrode;

[0014] The first electrode includes a first main body portion, a first fixing portion connected to the first main body portion, and a first insulating portion at least partially covering the first main body portion.

[0015] As a further improvement of the technical solution of this application, both the first main body and the first fixing part are cylindrical, wherein the outer diameter of the first fixing part is smaller than the outer diameter of the first main body.

[0016] As a further improvement of the technical solution of this application, the first insulating part is a ceramic sleeve, which is sleeved on the first main body to at least partially cover the first main body.

[0017] As a further improvement of the technical solution of this application, the first insulating part is an insulating plating layer plated on the first main body part.

[0018] As a further improvement of the technical solution of this application, the first electrode also includes a first transition portion connected to the first main body portion and a first external thread portion connected to the first transition portion, wherein the first external thread portion, the first transition portion, the first main body portion and the first fixing portion are connected in sequence.

[0019] As a further improvement of the technical solution of this application, the first transition portion is frustum-shaped and has a gradually changing outer diameter. The first transition portion includes a large-diameter end connected to the first main body portion and a small-diameter end connected to the first external thread portion.

[0020] As a further improvement of the present application, the first electrode assembly further includes a first shielding portion fixed to the first insulating portion, the first shielding portion being fixed to the outer surface of the housing to shield the first mounting hole.

[0021] As a further improvement of the technical solution of this application, the first shielding part is provided with a first through hole, and the first insulating part is fixed in the first through hole by an interference fit.

[0022] As a further improvement of the technical solution of this application, the first shielding part is further provided with a first clearance hole, one end of the first insulating part extends out of the first shielding part, and the other end of the first insulating part passes through the first through hole and is at least partially located in the first clearance hole.

[0023] As a further improvement of this application, the first shielding part is welded and fixed to the outer surface of the shell.

[0024] As a further improvement of this application, the first mounting hole is larger than the outer diameter of the first electrode assembly at the position corresponding to the first mounting hole, thereby making it easier for the first electrode assembly to pass through the first mounting hole.

[0025] As a further improvement of the technical solution of this application, the heating belt assembly includes several layers of heating belts, which are stacked and wound together to form a disc shape. Each layer of heating belt includes a wavy part and a first extension connected to one end of the wavy part.

[0026] The first connecting block includes a first mounting groove, and the first extension is received in the first mounting groove.

[0027] As a further improvement of the technical solution of this application, each first extension is in the shape of a straight strip, and the first extensions of the plurality of heating strips are parallel to each other; the first mounting groove of the first connecting block is a plurality of parallel grooves; the first extension is received in the corresponding first mounting groove.

[0028] As a further improvement to the technical solution of this application, the first extensions of the plurality of heating bands are arranged at equal intervals; the first mounting grooves of the first connecting block are arranged at equal intervals.

[0029] As a further improvement of the technical solution of this application, the first connecting block includes a first side surface, a second side surface opposite to the first side surface, and a first end surface;

[0030] The first mounting groove extends through the first end face and extends along the axial direction of the electric heater through the first side surface and the second side surface.

[0031] As a further improvement of the technical solution of this application, the first connecting block is made of metal material. The first connecting block includes a first mounting part, a first connecting part connected to the first mounting part, and a first clearance space located inside the first mounting part. The first mounting part includes a first surface and a second surface opposite to the first surface. The first fixing hole is provided in the first mounting part. The first fixing hole passes through the first surface and the second surface and communicates with the first clearance space.

[0032] As a further improvement of this application, the first fixing part extends at least partially into the first clearance space after passing through the first fixing hole.

[0033] As a further improvement of the present application, the electric heater further includes a support frame located at least partially in the installation space and a pin assembly for fixing the heating band assembly to the support frame along the axial direction of the electric heater, the support frame being fixed to the inner surface of the housing.

[0034] As a further improvement of the technical solution of this application, the support frame includes an inner side, an outer side, and a plurality of spokes connecting the inner side and the outer side; the outer side is located on a circular outline; the outer side is provided with a first notch and a second notch, wherein the first notch corresponds to the first electrode assembly, and the second notch corresponds to the second electrode assembly.

[0035] As a further improvement to the technical solution of this application, the pin assembly includes a pin, a first ceramic sleeve, a second ceramic sleeve, and an end cap; the pin includes an abutment portion and a pin portion connected to the abutment portion; the first ceramic sleeve includes a first base portion and a first cylindrical portion connected to the first base portion, the first base portion having a first insertion hole, and the first cylindrical portion having a channel communicating with the first insertion hole; the second ceramic sleeve includes a second insertion hole; the end cap has an installation insertion hole; the pin is inserted into the channel of the first ceramic sleeve through the first insertion hole, the pin passes through the channel and is inserted into the second insertion hole, and the pin passes through the second insertion hole and is inserted into the installation insertion hole.

[0036] As a further improvement of the technical solution of this application, the heating belt assembly includes a gap hole, the first cylindrical part is inserted into the gap hole, the first base of the first ceramic sleeve and the second ceramic sleeve are respectively located on both sides of the heating belt assembly, the support frame is provided with a mounting through hole, and the pin passes through the mounting through hole after exiting the second insertion hole and before being inserted into the mounting insertion hole.

[0037] As a further improvement of this application, the end cap is located on one side of the support frame, and the end cap is heated and melted to fill the mounting hole.

[0038] As a further improvement to the technical solution of this application, the mounting hole is an oblong hole, and the size of the oblong hole is larger than the outer diameter of the pin.

[0039] As a further improvement to the technical solution of this application, the housing includes a second mounting hole that penetrates the outer surface and the inner surface and communicates with the mounting space;

[0040] The electric heater further includes a second connecting block, which is connected to the heating belt assembly, and the second connecting block is provided with a second fixing hole;

[0041] The second electrode assembly includes a second electrode, the second electrode having a second fixing part, the second fixing part passing through the second mounting hole and being connected to the second fixing hole by a threaded engagement.

[0042] As a further improvement of this application, the first connecting block and the second connecting block have the same structure; the first electrode assembly and the second electrode assembly have the same structure.

[0043] This application also discloses an exhaust gas aftertreatment device, which includes: an intake assembly; an electric heater located downstream of the intake assembly along the airflow direction; a first exhaust gas aftertreatment module located downstream of the electric heater along the airflow direction; and a second exhaust gas aftertreatment module located downstream of the first exhaust gas aftertreatment module along the airflow direction.

[0044] A mixer assembly located downstream of the second exhaust gas aftertreatment module along the airflow direction;

[0045] A third exhaust gas aftertreatment module located downstream of the mixer assembly along the airflow direction; and an exhaust gas assembly located downstream of the third exhaust gas aftertreatment module along the airflow direction.

[0046] The electric heater is the aforementioned electric heater.

[0047] Compared to the prior art, the electric heater of this application includes a first connecting block with a first fixing hole; the first electrode assembly includes a first electrode with a first fixing part, and the first fixing part is connected to the first fixing hole by a threaded engagement; this arrangement avoids the structural reliability problems that may be caused by direct welding of the first electrode to the heating band assembly, and improves durability. Attached Figure Description

[0048] Figure 1 is a schematic diagram of the exhaust gas aftertreatment device of this application;

[0049] Figure 2 is a perspective view of the electric heater of this application in one embodiment;

[0050] Figure 3 is a three-dimensional schematic diagram of Figure 2 from another angle;

[0051] Figure 4 is the front view of Figure 2;

[0052] Figure 5 is the front view of Figure 3;

[0053] Figure 6 is a magnified view of part A within the frame in Figure 4;

[0054] Figure 7 is a magnified view of part B within the frame in Figure 4;

[0055] Figure 8 is the left view of Figure 2;

[0056] Figure 9 is a cross-sectional view along line CC in Figure 8;

[0057] Figure 10 is a partial exploded perspective view of Figure 2, in which the first electrode assembly and the second electrode assembly are separated;

[0058] Figure 11 is a partial exploded three-dimensional view of Figure 10 from another angle;

[0059] Figure 12 is a further partial exploded perspective view of Figure 10, wherein the first electrode assembly and the second electrode assembly are further disassembled;

[0060] Figure 13 is a partial exploded three-dimensional view of Figure 12 from another angle;

[0061] Figure 14 is a further partial exploded perspective view of Figure 12, in which the shell is further dissected;

[0062] Figure 15 is a partial exploded three-dimensional view of Figure 14 from another angle;

[0063] Figure 16 is a three-dimensional exploded view of the improvement in Figure 14;

[0064] Figure 17 is a three-dimensional exploded view of Figure 16 from another angle;

[0065] Figure 18 is a three-dimensional schematic diagram of one of the pin components in Figure 16;

[0066] Figure 19 is an exploded three-dimensional view of Figure 18;

[0067] Figure 20 is a three-dimensional schematic diagram of Figure 18 from another angle;

[0068] Figure 21 is an exploded three-dimensional view of Figure 20;

[0069] Figure 22 is an exploded perspective view of the first connecting block, the second connecting block, the heating belt assembly, the first electrode assembly, and the second electrode assembly;

[0070] Figure 23 is the front view of Figure 22;

[0071] Figure 24 is a three-dimensional exploded view of Figure 22 from another angle;

[0072] Figure 25 is the front view of Figure 24;

[0073] Figure 26 is a magnified view of the circled part D in Figure 23;

[0074] Figure 27 is a magnified view of the circled part E in Figure 23;

[0075] Figure 28 is a cross-sectional view along line FF in Figure 4. Detailed Implementation

[0076] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings. Where several specific embodiments exist, features in these embodiments may be combined with each other without conflict. When the description involves the accompanying drawings, unless otherwise stated, the same numbers or symbols in different drawings represent the same or similar elements. The content described in the following exemplary embodiments does not represent all embodiments of this application; rather, they are merely examples of products consistent with this application and as described in the claims.

[0077] The terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of protection of this application. It should be understood that the terms such as "first," "second," and similar words used in the specification and claims of this application do not indicate any order, quantity, or importance, but are merely used to distinguish features.

[0078] Referring to Figure 1, this application discloses an exhaust aftertreatment device, which includes an intake assembly 200, an electric heater 100 located downstream of the intake assembly 200 along the airflow direction, a first exhaust aftertreatment module 300 (e.g., a diesel oxidation catalyst, DOC) located downstream of the electric heater 200 along the airflow direction, a second exhaust aftertreatment module 400 (e.g., a diesel particulate filter, DPF) located downstream of the first exhaust aftertreatment module 300 along the airflow direction, a mixer assembly 500 located downstream of the second exhaust aftertreatment module 400 along the airflow direction, a urea nozzle 600 mounted on the mixer assembly 500, a third exhaust aftertreatment module 700 (e.g., a selective catalytic reduction, SCR) located downstream of the mixer assembly 500 along the airflow direction, and an exhaust assembly 800 located downstream of the third exhaust aftertreatment module 700 along the airflow direction. The first exhaust aftertreatment module 300, the second exhaust aftertreatment module 400, and the third exhaust aftertreatment module 700 are collectively referred to as exhaust aftertreatment modules. Referring to Figure 1, the airflow direction is indicated by the hollow arrow in Figure 1.

[0079] Referring to Figures 2 to 28, the embodiments illustrated in this application disclose an electric heater 100 used in the exhaust gas aftertreatment device. The electric heater 100 includes a housing 1, a heating band assembly 2 at least partially located in the housing 1, a first electrode assembly 3 mounted on the housing 1, a second electrode assembly 4 mounted on the housing 1, a first connecting block 5 connecting one end of the heating band assembly 2 to the first electrode assembly 3, a second connecting block 6 connecting the other end of the heating band assembly 2 to the second electrode assembly 4, a support frame 7 at least partially located in the housing 1, and a plurality of pin assemblies 8 fixing the heating band assembly 2 to the support frame 7 along the axial direction of the electric heater 100.

[0080] In the embodiment illustrated in this application, the housing 1 is made of a metallic material, such as stainless steel. The housing 1 is generally hollow and cylindrical, and has a mounting space 10. The housing 1 includes an outer surface 11 and an inner surface 12 opposite to the outer surface 11, the inner surface 12 being exposed in the mounting space 10. The housing 1 also includes a first mounting hole 13 penetrating the outer surface 11 and the inner surface 12 and communicating with the mounting space 10, and a second mounting hole 14 penetrating the outer surface 11 and the inner surface 12 and communicating with the mounting space 10. In the embodiment illustrated in this application, both the first mounting hole 13 and the second mounting hole 14 are circular through holes. Of course, those skilled in the art will understand that in other embodiments of this application, the first mounting hole 13 and the second mounting hole 14 can also be other shapes, including but not limited to elliptical holes, oblong holes, rectangular holes, trapezoidal holes, triangular holes, etc., which will not be elaborated further in this application. Additionally, in the embodiment illustrated in this application, both the outer surface 11 and the inner surface 12 are arc-shaped surfaces. Of course, those skilled in the art will understand that in other embodiments of this application, the outer surface 11 and the inner surface 12 may also be planar.

[0081] In the embodiment illustrated in this application, the heating band assembly 2 includes several layers of heating bands 21 made of metal material. In another embodiment illustrated in this application, the heating band assembly 2 includes seven layers of heating bands 21, each layer of heating band 21 including a wave portion 210, a first extension portion 211 connected to one end of the wave portion 210, and a second extension portion 212 connected to the other end of the wave portion 210. The wave portion 210 is generally wave-shaped, having crests and troughs. Adjacent layers of heating bands 21 are fixed together. In one embodiment of this application, adjacent layers of heating bands 21 are fixed together by brazing. Those skilled in the art will understand that the way adjacent layers of heating bands 21 are fixed together can be varied; for example, the crest of one heating band 21 may be fixed to the crest of an adjacent heating band 21; or the crest of one heating band 21 may be fixed to the trough of an adjacent heating band 21; or the trough of one heating band 21 may be fixed to the trough of an adjacent heating band 21. The heating belt assembly 2 includes a plurality of gap holes 22 located between two adjacent heating belts 21. Most of the gap holes 22 are used to allow exhaust gas to flow through, thereby heating the exhaust gas using the heating belt assembly 2.

[0082] Those skilled in the art will understand that the peaks of each heating band 21 can be the same or different, and the troughs of each heating band 21 can also be the same or different. The peaks of two adjacent heating bands 21 can be the same or different, and the troughs of two adjacent heating bands 21 can also be the same or different.

[0083] In the embodiment illustrated in this application, the plurality of heating belts 21 are stacked and wound together to form a disc shape. The heating belt assembly 2 comprises a plurality of layers radially from the inside out, wherein a gap 23 is provided between the inner layer heating belt assembly 2 and the outer layer heating belt assembly 2. The gap 23 is used to allow exhaust gas to pass through, thereby heating the exhaust gas using the heating belt assembly 2.

[0084] In the embodiments illustrated in this application, preferably, the length of each heating band 21 is the same to distribute the current as evenly as possible to each heating band 21. In the embodiments illustrated in this application, both the first extension 211 and the second extension 212 are generally straight strips. Those skilled in the art will understand that the term "straight strips" in this application does not require them to be completely flat and perfectly straight; appropriate curvature is also acceptable. In one embodiment of this application, the first extension 211 and the second extension 212 may even be inclined relative to the wavy portion 210. In the embodiments illustrated in this application, the plurality of heating bands 21 include a first end 24 formed by the plurality of first extensions 211 and a second end 25 formed by the plurality of second extensions 212. In the embodiments illustrated in this application, the plurality of first extensions 211 of the first end 24 are parallel to each other, and the plurality of second extensions 212 of the second end 25 are also parallel to each other.

[0085] Preferably, in one embodiment of this application, the distance between any two adjacent first extensions 211 is equal; in other words, the first extensions 211 are arranged at equal intervals. Compared to a design where the first extensions 211 are stacked and squeezed together, this arrangement is less likely to cause heat concentration after power is applied, thereby reducing the risk of excessively high local temperatures.

[0086] Similarly, in one embodiment of this application, the distance between any two adjacent second extensions 212 is equal; in other words, the second extensions 212 are arranged at equal intervals. Compared to a design where the second extensions 212 are stacked and compressed together, this arrangement is less likely to cause heat concentration after power is applied, thereby reducing the risk of excessively high local temperatures.

[0087] The first connecting block 5 is made of metal and includes a first mounting portion 51, a first connecting portion 52 connected to the first mounting portion 51, and a first clearance space 53 located inside the first mounting portion 51. The first mounting portion 51 includes a first surface 511 (e.g., an upper surface), a second surface 512 (e.g., a lower surface) opposite to the first surface 511, and a first fixing hole 513 penetrating the first surface 511 and the second surface 512 and communicating with the first clearance space 53. In one embodiment of this application, the first fixing hole 513 is an internally threaded hole. The first fixing hole 513 corresponds to the first mounting hole 13. In the embodiment illustrated in this application, the size of the first mounting hole 13 is larger than the size of the first fixing hole 513, thereby facilitating the passage of the first electrode assembly 3 through the first mounting hole 13 during assembly.

[0088] The first connecting portion 52 includes a first side surface 521, a second side surface 522 opposite to the first side surface 521, a first end surface 523, and a plurality of first mounting grooves 524 penetrating the first end surface 523. In the embodiment illustrated in this application, the first mounting grooves 524 penetrate the first side surface 521 and the second side surface 522 along the axial direction of the electric heater 100. The first mounting grooves 524 are used to accommodate the first extension 211. To improve the flexibility of installation, the length of the first mounting groove 524 is greater than the length of the first extension 211. This design, by accommodating the first extension 211 in the first mounting groove 524, helps to increase the contact area between the first extension 211 and the first connecting block 5, and helps to improve the connection stability between the two.

[0089] Similarly, the second connecting block 6 is made of metal and includes a second mounting portion 61, a second connecting portion 62 connected to the second mounting portion 61, and a second clearance space 63 located inside the second mounting portion 61. The second mounting portion 61 includes a third surface 611 (e.g., an outer surface), a fourth surface 612 (e.g., an inner surface) opposite to the third surface 611, and a second fixing hole 613 penetrating the third surface 611 and the fourth surface 612 and communicating with the second clearance space 63. In one embodiment of this application, the second fixing hole 613 is an internally threaded hole. The second fixing hole 613 corresponds to the second mounting hole 14. In the embodiment illustrated in this application, the size of the second mounting hole 14 is larger than the size of the second fixing hole 613, thereby facilitating the passage of the second electrode assembly 4 through the second mounting hole 14 during assembly.

[0090] The second connecting portion 62 includes a third side surface 621, a fourth side surface 622 opposite to the third side surface 621, a second end surface 623, and a plurality of second mounting grooves 624 penetrating the second end surface 623. In the embodiment illustrated in this application, the second mounting grooves 624 penetrate the third side surface 621 and the fourth side surface 622 along the axial direction of the electric heater 100. The second mounting grooves 624 are used to accommodate the second extension 212. To improve the flexibility of installation, the length of the second mounting groove 624 is greater than the length of the second extension 212. This design, by accommodating the second extension 212 in the second mounting groove 624, helps to increase the contact area between the second extension 212 and the second connecting block 6, and helps to improve the connection stability between the two.

[0091] The first electrode assembly 3 includes a first electrode 31, a first insulating portion 32 disposed on the first electrode 31, and a first shielding portion 33 fixed to the first insulating portion 32. In one embodiment of this application, the first electrode 31 includes a first main body portion 311, a first transition portion 312 connected to one end of the first main body portion 311, a first fixing portion 313 connected to the other end of the first main body portion 311, and a first external thread portion 314 connected to the first transition portion 312. In the embodiment illustrated in this application, the first external thread portion 314, the first transition portion 312, the first main body portion 311, and the first fixing portion 313 are connected sequentially. In the embodiment illustrated in this application, the outer diameter of the first main body portion 311 is larger than the outer diameter of the first external thread portion 314. The first transition portion 312 is frustum-shaped, including a large-diameter end connected to the first main body portion 311 and a small-diameter end connected to the first external thread portion 314, thereby causing the first main body portion 311, the first transition portion 312, and the first external thread portion 314 to gradually change. The outer diameter of the first fixing part 313 is smaller than the outer diameter of the first main body part 311.

[0092] In this embodiment, the first insulating part 32 is a ceramic sleeve that is fitted onto the first main body part 311 to insulate the first electrode 31 from the first shielding part 33. The first shielding part 33 is provided with a first through hole 330, and the first insulating part 32 is fixed in the first through hole 330 by an interference fit.

[0093] Of course, the first insulating part 32 can also be an insulating plating layer (such as a ceramic plating layer) plated on the first main body part 311, which can also play an insulating role, and this application will not elaborate further on this.

[0094] In the illustrated embodiment of this application, the first shielding portion 33 is welded and fixed to the outer surface 11 of the housing 1, and the first shielding portion 33 shields the first mounting hole 13. Furthermore, to prevent the heat generated during welding from damaging the first electrode 31 and / or the first insulating portion 32, a first clearance hole 331 is provided inside the first shielding portion 33 to quickly reduce heat transfer by allowing air to pass through. In the illustrated embodiment of this application, the first clearance hole 331 is generally tapered, with its diameter at the end radially closer to the heating band assembly 2 being larger than the diameter at the end farther from the heating band assembly 2.

[0095] In the embodiment illustrated in this application, the first shielding part 33 is provided with a first force-applying part 332, which is a hexagonal nut that includes six outer surfaces.

[0096] In this embodiment, the first electrode 31, the first insulating part 32, and the first shielding part 33 are assembled into an integral first electrode assembly 3. Then, the first electrode assembly 3 is passed through the first mounting hole 13. In the embodiment illustrated in this application, the diameter of the first mounting hole 13 is larger than the outer diameter of the first electrode assembly 3 at the position corresponding to the first mounting hole 13, thereby making it easier for the first electrode assembly 3 to pass through the first mounting hole 13. This design improves the flexibility of installation and enhances installation convenience. The first fixing part 313 passes through the first mounting hole 13 and is fixed in the first fixing hole 513. In one embodiment of this application, the first fixing part 313 has an external thread (not shown), which engages with the internal thread of the first fixing hole 513. The external thread of the first fixing part 313 can be tightened with the internal thread of the first fixing hole 513 using the hexagonal nut and a matching installation tool. When the first electrode assembly 3 is installed in place, the first shielding part 33 is located between the first electrode 31 and the first shielding part 33, and the first shielding part 33 extends through the first mounting hole 13 and the first clearance hole 331, and at least partially extends into the mounting space 10.

[0097] Of course, those skilled in the art will understand that the first shielding part 33 may not have the first force-applying part 332. In this case, when installing the first electrode assembly 3 onto the first connecting block 5, the first external thread 314 can be used, and an installation tool can be used to tighten the external thread of the first fixing part 313 and the internal thread of the first fixing hole 513.

[0098] In this embodiment, the first fixing part 313 protrudes from the second surface 512 to facilitate observation of the installation. The first fixing part 313 partially protrudes into the first clearance space 53; however, a suitable safe distance is maintained between the end of the first fixing part 313 and the heating band assembly 2 directly opposite it, preventing direct contact between the end of the first fixing part 313 and the heating band assembly 2. Those skilled in the art will understand that by providing the first clearance space 53, this application helps to reduce the risk of direct contact between the end of the first fixing part 313 and the heating band assembly 2 directly opposite it.

[0099] Compared with related technologies, this application achieves the connection and fixation of the first electrode 31 and the first connecting block 5 through mechanical connection, avoiding the damage to the first electrode 31 that may be caused by the high temperature generated during welding connection.

[0100] Similarly, the second electrode assembly 4 includes a second electrode 41, a second insulating portion 42 disposed on the second electrode 41, and a second shielding portion 43 fixed to the second insulating portion 42. In one embodiment of this application, the second electrode 41 includes a second main body portion 411, a second transition portion 412 connected to one end of the second main body portion 411, a second fixing portion 413 connected to the other end of the second main body portion 411, and a second external thread portion 414 connected to the second transition portion 412. In the embodiment illustrated in this application, the second external thread portion 414, the second transition portion 412, the second main body portion 411, and the second fixing portion 413 are connected sequentially. In the embodiment illustrated in this application, the outer diameter of the second main body portion 411 is larger than the outer diameter of the second external thread portion 414. The second transition portion 412 is frustum-shaped, including a large-diameter end connected to the second main body portion 411 and a small-diameter end connected to the second external thread portion 414, thereby causing the second main body portion 411, the second transition portion 412, and the second external thread portion 414 to gradually change. The outer diameter of the second fixing part 413 is smaller than the outer diameter of the second main body part 411.

[0101] In this embodiment, the second insulating part 42 is a ceramic sleeve that is fitted onto the second main body part 411 to insulate the second electrode 41 from the second shielding part 43. The second shielding part 43 is provided with a second through hole 430, and the second insulating part 42 is fixed in the second through hole 430 by an interference fit.

[0102] Of course, the second insulating part 42 can also be an insulating plating layer (such as a ceramic plating layer) plated on the second main body part 411, which can also play an insulating role, and this application will not elaborate on this.

[0103] In the illustrated embodiment of this application, the second shielding portion 43 is welded and fixed to the outer surface 11 of the housing 1, and the second shielding portion 43 shields the second mounting hole 14. Furthermore, to prevent the heat generated during welding from damaging the second electrode 41 and / or the second insulating portion 42, a second clearance hole 431 is provided inside the second shielding portion 43 to quickly reduce heat transfer by allowing air to pass through. In the illustrated embodiment of this application, the second clearance hole 431 is generally tapered, with its diameter at the end radially closer to the heating band assembly 2 being larger than the diameter at the end farther from the heating band assembly 2.

[0104] In the embodiment illustrated in this application, the second shielding part 43 is provided with a second force-applying part 432, which is a hexagonal nut that includes six outer surfaces.

[0105] In this embodiment, the second electrode 41, the second insulating part 42, and the second shielding part 43 are assembled into an integral second electrode assembly 4. The second electrode assembly 4 is then passed through the second mounting hole 14. In the embodiment illustrated in this application, the diameter of the second mounting hole 14 is larger than the outer diameter of the second electrode assembly 4 at the position corresponding to the second mounting hole 14, thereby making it easier for the second electrode assembly 4 to pass through the second mounting hole 14. This design improves the flexibility of installation and enhances installation convenience. The second fixing part 413 passes through the second mounting hole 14 and is fixed in the second fixing hole 613. In one embodiment of this application, the second fixing part 413 has an external thread (not shown), which engages with the internal thread of the second fixing hole 613. The external thread of the second fixing part 413 can be tightened into the internal thread of the second fixing hole 613 using the hexagonal nut and a matching installation tool. When the second electrode assembly 4 is installed in place, the second shielding part 43 is located between the second electrode 41 and the second shielding part 43, and the second shielding part 43 extends through the second mounting hole 14 and the second clearance hole 431, and at least partially extends into the mounting space 10.

[0106] Of course, those skilled in the art will understand that the second shielding part 43 may not have the second force-applying part 432. In this case, when installing the second electrode assembly 4 onto the second connecting block 6, the second external thread 414 can be used, and an installation tool can be used to tighten the external thread of the second fixing part 413 and the internal thread of the second fixing hole 613.

[0107] In the embodiment illustrated in this application, the second fixing part 413 protrudes from the fourth surface 612 to facilitate observation of the installation. The second fixing part 413 partially protrudes into the second clearance space 63; however, a suitable safe distance is maintained between the end of the second fixing part 413 and the heating band assembly 2 directly opposite it, preventing direct contact between the end of the second fixing part 413 and the heating band assembly 2. By providing the second clearance space 63, this application helps reduce the risk of direct contact between the end of the second fixing part 413 and the heating band assembly 2 directly opposite it.

[0108] Compared with related technologies, this application achieves the connection and fixation of the second electrode 41 and the second connecting block 6 through mechanical connection, avoiding the damage to the second electrode 41 that may be caused by the high temperature generated during welding connection.

[0109] Those skilled in the art will understand that one of the first electrode 31 and the second electrode 41 in this application is a positive electrode and the other is a negative electrode. Preferably, the first electrode assembly 3 and the second electrode assembly 4 have identical structures to share components and save costs. Preferably, the first connecting block 5 and the second connecting block 6 have identical structures to share components and save costs.

[0110] The support frame 7 is made of metal. The support frame 7 includes an inner edge 71, an outer edge 72, and a plurality of spokes 73 connecting the inner edge 71 and the outer edge 72. The outer edge 72 lies on a circular outline. The outer edge 72 has a first notch 721 and a second notch 722, wherein the first notch 721 corresponds to the first electrode assembly 3, and the second notch 722 corresponds to the second electrode assembly 4. The first notch 721 and the second notch 722 allow exhaust gas to pass through, reducing obstruction of the first electrode assembly 3 and the second electrode assembly 4, thereby helping to reduce the risk of overheating of the first electrode 31 and the second electrode 41. The inner edge 71 has a perimeter-encircling frame shape to increase structural strength.

[0111] Those skilled in the art will understand that, typically, to improve structural strength, the outer edge 72 is designed as an integral frame structure. However, this design causes the frame structure to obstruct the first electrode assembly 3 and the second electrode assembly 4, hindering heat dissipation. This application innovatively designs the first notch 721 and the second notch 722, resolving the risk of overheating of the first electrode 31 and the second electrode 41 due to obstruction by the outer edge 72.

[0112] In this embodiment, the outer edge 72 is welded and fixed to the inner surface 12 of the housing 1 to be fixed to the housing 1.

[0113] The inner edge 71 and the outer edge 72 are connected by spokes 73, which enhance the structural strength. In the embodiment illustrated in this application, each spoke 73 has a plurality of mounting holes 731. Preferably, the mounting holes 731 are oblong. Of course, those skilled in the art will understand that the mounting holes 731 can also be designed in other shapes. The mounting holes 731 can adjust the installation tolerance, which helps to improve the convenience of assembling the pin assembly 8.

[0114] The pin assembly 8 includes a pin 81, a first ceramic sleeve 82, a second ceramic sleeve 83, and an end cap 84. In one embodiment of this application, both the pin 81 and the end cap 84 are made of metal. The pin 81 includes an abutment portion 811 and a pin portion 812 connected to the abutment portion 81. The first ceramic sleeve 82 includes a first base 821 and a first cylindrical portion 822 connected to the first base 821. The first base 821 has a first insertion hole 8211, and the first cylindrical portion 822 has a channel 8221 communicating with the first insertion hole 8211. The second ceramic sleeve 83 includes a second insertion hole 831. The end cap 84 has an installation insertion hole 841. In the embodiment illustrated in this application, the end cap 84 is generally spherical. Of course, those skilled in the art will understand that the shape of the end cap 84 can also be other shapes, and this application is not limited thereto.

[0115] During assembly, the pin 81 is first inserted into the channel 8221 of the first ceramic sleeve 82 through the first insertion hole 8211. The abutting portion 811 abuts against the first base 821 to limit the position of the abutting portion 811. The pin portion 812 passes through the first cylindrical portion 822 and extends out of the first cylindrical portion 822. Then, the pin 81 and the first ceramic sleeve 82 are inserted as a whole into the corresponding gap hole 22, with the first cylindrical portion 822 of the first ceramic sleeve 82 located in the corresponding gap hole 22 to prevent the pin 81 from contacting the heating belt assembly 2. Then, the second ceramic sleeve 83 is fitted onto the pin portion 812, with the pin portion 812 passing through the second insertion hole 831 and extending out of the second ceramic sleeve 83. At this time, the first base 821 of the first ceramic sleeve 82 and the second ceramic sleeve 83 are located on both sides of the heating belt assembly 2 along the axial direction. The pin portion 812 passes through the corresponding mounting hole 731 on the support frame 7. Then, the end cap 84 is fitted onto the pin portion 812. In the embodiment illustrated in this application, the pin portion 812 is inserted into the mounting hole 841 and extends beyond the end cap 84. Of course, those skilled in the art will understand that the pin portion 812 may not extend beyond the end cap 84. Finally, the end cap 84 is melted by heating. The melted end cap 84 serves as filler and solder, fixing the pin portion 812 and the support frame 7 together on one hand, and filling the mounting hole 731 on the other. Those skilled in the art will understand that the size of the mounting hole 731 in this application is larger than the size of the pin portion 812, so that the pin portion 812 can pass through the mounting hole 731. In addition, this application innovatively solves the problem of filling the mounting hole 731 by setting the end cap 84, which not only improves the aesthetics, but also increases the bonding force between the pin part 812 and the support frame 7.

[0116] Compared with the prior art, the electric heater 100 of this application includes a first connecting block 5, the first connecting block 5 having a first fixing hole 513; the first electrode assembly 3 includes a first electrode 31, the first electrode 31 having a first fixing part 313, the first fixing part 313 being connected to the first fixing hole 513 by a threaded engagement; this arrangement avoids the structural reliability problems that may be caused by direct welding of the first electrode 31 to the heating band assembly 2, and improves durability.

[0117] Similarly, the electric heater 100 of this application includes a second connecting block 6, which has a second fixing hole 613; the second electrode assembly 4 includes a second electrode 41, which has a second fixing part 413, and the second fixing part 413 is connected to the second fixing hole 613 by a threaded engagement; this arrangement avoids the structural reliability problems that may be caused by direct welding of the second electrode 41 to the heating band assembly 2, and improves durability.

[0118] Furthermore, by providing the first connecting block 5 and the second connecting block 6 with the above structures, the first mounting groove 524 on the first connecting block 5 is used to accommodate the first extension 211, and the second mounting groove 624 on the second connecting block 6 is used to accommodate the second extension 212. This facilitates the relatively uniform distribution of current to each heating band 21 through the first connecting block 5 and the second connecting block 6, thereby improving the temperature uniformity of the electric heater 100 and reducing the risk of local overheating.

[0119] The above embodiments are only used to illustrate this application and are not intended to limit the technical solutions described in this application. The understanding of this specification should be based on those skilled in the art. Although this specification has described this application in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to this application. All technical solutions and improvements that do not depart from the spirit and scope of this application should be covered within the scope of the claims of this application.

Claims

1. An electric heater (100) configured for use in an exhaust gas aftertreatment device, characterized in that, The electric heater (100) comprises: a housing (1) comprising a mounting space (10), an outer surface (11), an inner surface (12) opposite to the outer surface (11), and a first mounting hole (13) penetrating through the outer surface (11) and the inner surface (12) and communicating with the mounting space (10); a heating band assembly (2) located at least partially in the mounting space (10); a first connecting block (5) connected with the heating band assembly (2), the first connecting block (5) being provided with a first fixing hole (513); a first electrode assembly (3) comprising a first electrode (31) provided with a first fixing part (313) penetrating through the first mounting hole (13) and connected with the first fixing hole (513) through threaded cooperation; a second electrode assembly (4) comprising a second electrode (41) directly or indirectly connected with the heating band assembly (2); one of the first electrode (31) and the second electrode (41) is a positive electrode, and the other is a negative electrode.

2. The electric heater (100) as claimed in claim 1, characterized in that: The first fixing hole (513) is provided with an internal thread, and the first fixing part (313) is provided with an external thread, the internal thread and the external thread being cooperated.

3. The electric heater (100) as claimed in claim 1, wherein: The first electrode assembly (3) further comprises a first insulating part (32) arranged on the first electrode (31); The first electrode (31) comprises a first main body part (311), the first fixing part (313) being connected with the first main body part (311), and the first insulating part (32) at least partially covering the first main body part (311).

4. The electric heater (100) as claimed in claim 3, characterized in that: The first main body part (311) and the first fixing part (313) are both in a cylindrical shape, wherein an outer diameter of the first fixing part (313) is smaller than an outer diameter of the first main body part (311).

5. The electric heater (100) as claimed in claim 3, wherein: The first insulating part (32) is a ceramic sleeve, which is sleeved on the first main body part (311) to at least partially cover the first main body part (311).

6. The electric heater (100) as claimed in claim 3, wherein: The first insulating part (32) is an insulating plating layer plated on the first main body part (311).

7. The electric heater (100) as claimed in claim 3, wherein: The first electrode (31) further comprises a first transition part (312) connected with the first main body part (311), and a first external thread part (314) connected with the first transition part (312), the first external thread part (314), the first transition part (312), the first main body part (311), and the first fixing part (313) being connected in sequence.

8. The electric heater (100) as claimed in claim 7, characterized in that: The first transition part (312) is in a circular truncated cone shape and has a gradually changing outer diameter, the first transition part (312) comprising a large-diameter end connected with the first main body part (311) and a small-diameter end connected with the first external thread part (314).

9. The electric heater (100) as claimed in claim 3, wherein: The first electrode assembly (3) further comprises a first shielding part (33) fixed to the first insulation part (32), and the first shielding part (33) is fixed to the outer surface (11) of the shell (1) to shield the first mounting hole (13).

10. The electric heater (100) as claimed in claim 9, characterized in that: The first shielding part (33) is provided with a first through hole (330), and the first insulation part (32) is fixed in the first through hole (330) in an interference fit.

11. The electric heater (100) as claimed in claim 9, wherein: The first shielding part (33) is further provided with a first displacement hole (331), one end of the first insulation part (32) extends out of the first shielding part (33), and the other end of the first insulation part (32) passes through the first through hole (330) and is at least partially located in the first displacement hole (331).

12. The electric heater (100) as claimed in claim 9, wherein: The first shielding part (33) is welded and fixed to the outer surface (11) of the shell (1).

13. The electric heater (100) as claimed in claim 1, wherein: The first mounting hole (13) is larger than the outer diameter of the first electrode assembly (3) at the position corresponding to the first mounting hole (13), so that the first electrode assembly (3) is easily passed through the first mounting hole (13).

14. The electric heater (100) as claimed in claim 1, wherein: The heating band assembly (2) comprises a plurality of layers of heating bands (21), and the plurality of layers of heating bands (21) are stacked and wound to form a disc shape, each layer of heating band (21) comprises a wave part (210) and a first extension part (211) connected to one end of the wave part (210); The first connecting block (5) comprises a first mounting groove (524), and the first extension part (211) is accommodated in the first mounting groove (524).

15. The electric heater (100) as claimed in claim 14, characterized in that: Each first extension part (211) is in the shape of a straight strip, and the first extension parts (211) of the plurality of layers of heating bands (21) are parallel to each other; The first mounting groove (524) of the first connecting block (5) is a plurality of and parallel to each other; The first extension part (211) is accommodated in the corresponding first mounting groove (524).

16. The electric heater (100) as claimed in claim 15, characterized in that: The first extension parts (211) of the plurality of layers of heating bands (21) are arranged at equal intervals; and the first mounting grooves (524) of the first connecting block (5) are arranged at equal intervals.

17. The electric heater (100) as claimed in claim 14, wherein: The first connecting block (5) comprises a first side surface (521), a second side surface (522) opposite to the first side surface (521), and a first end surface (523); The first mounting groove (524) penetrates the first end surface (523), and the first mounting groove (524) penetrates the first side surface (521) and the second side surface (522) in the axial direction of the electric heater (100).

18. The electric heater (100) as claimed in claim 14, wherein: The first connecting block (5) is made of a metal material, and the first connecting block (5) comprises a first mounting part (51), a first connecting part (52) connected to the first mounting part (51), and a first displacement space (53) located on the inner side of the first mounting part (51); The first mounting portion (51) comprises a first surface (511) and a second surface (512) opposite to the first surface (511), and the first fixing hole (513) is arranged in the first mounting portion (51) and penetrates the first surface (511) and the second surface (512) and communicates with the first accommodation space (53).

19. The electric heater (100) as claimed in claim 18, characterized in that: The first fixing portion (313) at least partially protrudes into the first accommodation space (53) after penetrating the first fixing hole (513).

20. The electric heater (100) as claimed in claim 1, wherein: The electric heater (100) further comprises a support frame (7) located at least partially in the mounting space (10) and a pin assembly (8) for fixing the heating band assembly (2) to the support frame (7) along the axial direction of the electric heater (100), and the support frame (7) is fixed to the inner surface (12) of the shell (1).

21. The electric heater (100) as claimed in claim 20, characterized in that: The support frame (7) comprises an inner edge portion (71), an outer edge portion (72), and a plurality of spokes (73) connecting the inner edge portion (71) and the outer edge portion (72). The outer edge portion (72) is located on a circular contour line, and the outer edge portion (72) is provided with a first notch (721) corresponding to the first electrode assembly (3) and a second notch (722) corresponding to the second electrode assembly (4).

22. The electric heater (100) as claimed in claim 20, characterized in that: The pin assembly (8) comprises a pin (81), a first ceramic sleeve (82), a second ceramic sleeve (83), and an end cap (84). The pin (81) comprises an abutting portion (811) and a pin portion (812) connected to the abutting portion (811). The first ceramic sleeve (82) comprises a first base portion (821) and a first cylindrical portion (822) connected to the first base portion (821), the first base portion (821) is provided with a first insertion hole (8211), and the first cylindrical portion (822) is provided with a channel (8221) in communication with the first insertion hole (8211). The second ceramic sleeve (83) comprises a second insertion hole (831), and the end cap (84) is provided with a mounting insertion hole (841). The pin (81) is inserted into the channel (8221) of the first ceramic sleeve (82) from the first insertion hole (8211) of the first ceramic sleeve (82), the pin (81) penetrates out of the channel (8221) and is inserted into the second insertion hole (831), and the pin (81) penetrates out of the second insertion hole (831) and is inserted into the mounting insertion hole (841).

23. The electric heater (100) as claimed in claim 22, characterized in that: The heating band assembly (2) comprises a gap hole (22), the first cylindrical portion (822) is inserted into the gap hole (22), the first base portion (821) of the first ceramic sleeve (82) and the second ceramic sleeve (83) are located on both sides of the heating band assembly (2) respectively, the support frame (7) is provided with a mounting perforation (731), and the pin (81) penetrates through the mounting perforation (731) after penetrating out of the second insertion hole (831) and before being inserted into the mounting insertion hole (841).

24. The electric heater (100) as claimed in claim 23, characterized in that: The end cap (84) is located on one side of the support frame (7), and the end cap (84) is filled into the mounting hole (731) after being heated and melted.

25. The electric heater (100) as claimed in claim 23, characterized in that: The mounting hole (731) is a waist-shaped hole, and the size of the waist-shaped hole is greater than the outer diameter of the pin (81).

26. The electric heater (100) as claimed in claim 1, wherein: The shell (1) comprises a second mounting hole (14) penetrating through the outer surface (11) and the inner surface (12) and communicating with the mounting space (10). The electric heater (100) further comprises a second connecting block (6) connected with the heating belt assembly (2), and the second connecting block (6) is provided with a second fixing hole (613). The second electrode assembly (4) comprises a second electrode (41) provided with a second fixing part (413), and the second fixing part (413) penetrates through the second mounting hole (14) and is connected with the second fixing hole (613) through threaded cooperation. The first connecting block (5) and the second connecting block (6) are the same in structure, and the first electrode assembly (3) and the second electrode assembly (4) are the same in structure.

27. The electric heater (100) as claimed in claim 26, characterized in that: It comprises:

28. An exhaust gas aftertreatment device, characterized by An air inlet assembly (200); An electric heater (100) located downstream of the air inlet assembly (200) in the airflow direction; A first tail gas aftertreatment module (300) located downstream of the electric heater (100) in the airflow direction; A second tail gas aftertreatment module (400) located downstream of the first tail gas aftertreatment module (300) in the airflow direction; A mixer assembly (500) located downstream of the second tail gas aftertreatment module (400) in the airflow direction; A third tail gas aftertreatment module (700) located downstream of the mixer assembly (500) in the airflow direction; And an air outlet assembly (800) located downstream of the third tail gas aftertreatment module (700) in the airflow direction; The electric heater (100) is the electric heater (100) according to any one of claims 1 to 27. ​

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