Electric heater and exhaust gas aftertreatment device

Abstract

An electric heater, comprising a housing, a heating strip assembly, a first electrode assembly, a second electrode assembly, a support and several pin assemblies. The support is provided with several mounting through holes. The pin assemblies fix a heating strip to the support in the axial direction of the electric heater. Each pin assembly comprises a first ceramic sleeve, a second ceramic sleeve and a pin, wherein the first ceramic sleeve is inserted into and through a mounting through hole; the second ceramic sleeve is at least partially sleeved on the first ceramic sleeve; and the pin runs through the first ceramic sleeve and the second ceramic sleeve and is inserted into a clearance hole, and the pin is fixed to the heating strip. By means of such arrangements, the pin assemblies of the present application achieve insulation from the support while fixing the heating strip. In addition, the present application further discloses 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. 202411523561.X, filed on October 29, 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 operating temperature of the exhaust gas after-treatment carrier. It is one of the important technical means in the industry.

[0007] Electric heaters typically include a housing, a heating element, electrodes, a support frame, and a pin assembly, wherein the pin assembly is used to fix the heating element to the support frame. However, how to achieve insulation between the support frame and the heating element is a technical problem faced by those skilled in the art. Summary of the Invention

[0008] The purpose of this application is to provide an electric heater with an improved structure and an exhaust gas aftertreatment device.

[0009] To achieve the above objectives, this application adopts the following technical solution: an electric heater, comprising:

[0010] A housing, the housing including an installation space;

[0011] A heating band assembly, at least partially located in the installation space, the heating band assembly comprising a plurality of heating bands stacked and wound together to form a disc shape, each heating band layer including a corrugated portion; the heating band assembly also includes a plurality of gap holes located between adjacent heating band layers.

[0012] A first electrode assembly is electrically connected directly or indirectly to one end of the heating band assembly;

[0013] The second electrode assembly is electrically connected directly or indirectly to the other end of the heating band assembly;

[0014] A support frame, at least partially located within the mounting space, the support frame having a plurality of mounting holes; and

[0015] A plurality of pin assemblies, wherein the pin assemblies fix the heating band to the support frame along the axial direction of the electric heater;

[0016] The pin assembly includes a first ceramic sleeve, a second ceramic sleeve, and a pin; the first ceramic sleeve is inserted into and passes through the mounting hole, the second ceramic sleeve is at least partially fitted onto the first ceramic sleeve, the second ceramic sleeve is located between the heating band and the support frame along the axial direction of the electric heater, the pin passes through the first ceramic sleeve and the second ceramic sleeve and is inserted into the gap hole, and the pin is fixed to the heating band.

[0017] As a further improvement of the technical solution of this application, the first ceramic sleeve includes a first base and a first cylindrical part connected to the first base. The first base is provided with a first insertion hole, and the first cylindrical part is provided with a channel communicating with the first insertion hole. The first cylindrical part is inserted into and passes through the mounting hole, and the first base abuts against one side of the support frame.

[0018] The second ceramic sleeve includes a second insertion hole, the first cylindrical portion is inserted into the second insertion hole, and the second ceramic sleeve abuts against the other side of the support frame;

[0019] The pin includes an abutment portion and a pin portion connected to the abutment portion. The pin portion is inserted into and passes through the first socket and the channel. The pin portion is fixed to the heating band. The abutment portion abuts against the first base.

[0020] As a further improvement to this application, the pin portion is welded and fixed to the heating band.

[0021] As a further improvement to the technical solution of this application, the pin portion is brazed and fixed to the heating band.

[0022] As a further improvement of this application, the second ceramic sleeve is tightly held between the heating band and the support frame along the axial direction of the electric heater.

[0023] As a further improvement of this application, the first cylindrical part is inserted into the second insertion hole, but does not protrude through the second ceramic sleeve.

[0024] As a further improvement of the technical solution of this application, each layer of heating band includes a first extension connected to one end of the wave section and a second extension connected to the other end of the wave section.

[0025] The electric heater also includes:

[0026] A first connecting block, wherein the first connecting block is provided with a plurality of first mounting slots, and the first extension is at least partially received in the first mounting slots; and

[0027] The second connecting block is provided with a plurality of second mounting slots, and the second extension is at least partially received in the second mounting slots;

[0028] The first electrode assembly includes a first electrode, which is connected to the first connecting block;

[0029] The second electrode assembly includes a second electrode, which is connected to the second connecting block;

[0030] One of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0031] As a further improvement to the technical solution of this application, each first extension is in the shape of a straight strip; and / or

[0032] Each second extension is in the shape of a straight strip.

[0033] 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 plurality of first mounting grooves of the first connecting block are parallel to each other.

[0034] Each second extension is in the shape of a straight strip, and the second extensions of the plurality of heating strips are parallel to each other; the plurality of second mounting grooves of the second connecting block are parallel to each other;

[0035] The first extensions of the plurality of heating strips are arranged at equal intervals; the first mounting grooves of the first connecting blocks are arranged at equal intervals.

[0036] The second extensions of the plurality of heating bands are arranged at equal intervals; the second mounting slots of the second connecting blocks are arranged at equal intervals.

[0037] This application also discloses an exhaust gas aftertreatment device, which includes:

[0038] Intake components;

[0039] An electric heater located downstream of the intake assembly along the airflow direction;

[0040] A first exhaust gas aftertreatment module located downstream of the electric heater along the airflow direction;

[0041] A second exhaust gas aftertreatment module located downstream of the first exhaust gas aftertreatment module along the airflow direction;

[0042] A mixer assembly located downstream of the second exhaust gas aftertreatment module along the airflow direction;

[0043] A third exhaust gas aftertreatment module located downstream of the mixer assembly along the airflow direction; and

[0044] An exhaust assembly located downstream of the third exhaust gas aftertreatment module along the airflow direction;

[0045] The electric heater is the aforementioned electric heater.

[0046] Compared to existing technologies, the electric heater of this application includes a heating band assembly, a support frame, and several pin assemblies. The pin assemblies fix the heating band to the support frame along the axial direction of the electric heater. Each pin assembly includes a first ceramic sleeve, a second ceramic sleeve, and a pin. The first ceramic sleeve is inserted into and passes through the mounting hole. The second ceramic sleeve is at least partially fitted onto the first ceramic sleeve, and is located between the heating band and the support frame along the axial direction of the electric heater. The pin passes through the first and second ceramic sleeves and is inserted into the gap hole, and is fixed to the heating band. With this configuration, the second ceramic sleeve of this application can limit the distance between the heating band and the support frame; the pin assembly achieves both fixing the heating band and insulation from the support frame. Attached Figure Description

[0047] Figure 1 is a schematic diagram of the exhaust gas aftertreatment device of this application.

[0048] Figure 2 is a perspective view of the electric heater of this application in one embodiment.

[0049] Figure 3 is a three-dimensional schematic diagram of Figure 2 from another angle.

[0050] Figure 4 is a front view of Figure 2. Figure 5 is a front view of Figure 3.

[0051] Figure 6 is a magnified view of part A within the frame in Figure 4.

[0052] Figure 7 is a magnified view of part B within the frame in Figure 4. Figure 8 is a left view of Figure 2.

[0053] Figure 9 is a cross-sectional view along line CC in Figure 8.

[0054] Figure 10 is a partial exploded perspective view of Figure 2, in which the first electrode assembly and the second electrode assembly are separated.

[0055] Figure 11 is a partial exploded view of Figure 10 from another angle.

[0056] Figure 12 is a partial exploded three-dimensional view of Figure 10.

[0057] Figure 13 is a partial exploded view of Figure 12 from another angle.

[0058] Figure 14 is a further exploded three-dimensional view of Figure 12.

[0059] Figure 15 is a three-dimensional schematic diagram of a pin assembly. Figure 16 is an exploded three-dimensional view of Figure 15.

[0060] Figure 17 is a three-dimensional schematic diagram of Figure 15 from another angle. Figure 18 is an exploded three-dimensional view of Figure 17.

[0061] Figure 19 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.

[0062] Figure 20 is a front view of the first connecting block, the second connecting block, the heating belt assembly, the first electrode assembly, and the second electrode assembly.

[0063] Figure 21 is a rear view of Figure 20. Figure 22 is a magnified view of the circled portion D in Figure 20.

[0064] Figure 23 is a magnified view of the circled part E in Figure 20.

[0065] Figure 24 is a cross-sectional view along line FF in Figure 4. Detailed Implementation

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Referring to Figures 2 to 24, the embodiments illustrated in this application disclose an electric heater 100 for use 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] In the embodiment illustrated in this application, 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.

[0083] Of course, those skilled in the art will understand that the first insulating part 32 is also 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.

[0084] 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.

[0085] 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.

[0086] In the embodiment illustrated in this application, 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 into 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.

[0087] 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.

[0088] In the embodiment illustrated in this application, 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 directly opposite it. 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.

[0089] 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.

[0090] 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.

[0091] In the embodiment illustrated in this application, 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.

[0092] Of course, those skilled in the art will understand that the second insulating part 42 is also 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 further on this.

[0093] 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, the interior of the second shielding portion 43 is also provided with a second clearance hole 431 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.

[0094] 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.

[0095] In the embodiment illustrated in this application, 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.

[0096] 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.

[0097] 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 opposite heating band assembly 2 to prevent direct contact between the end of the second fixing part 413 and the opposite heating band assembly 2. Those skilled in the art will understand that by providing the second clearance space 63, this application helps to reduce the risk of direct contact between the end of the second fixing part 413 and the opposite heating band assembly 2.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] In the embodiment illustrated in this application, the outer edge 72 is welded and fixed to the inner surface 12 of the housing 1 to be fixed to the housing 1.

[0103] The inner edge 71 and the outer edge 72 are connected by spokes 73, which serve to strengthen the structure. In the embodiment illustrated in this application, each spoke 73 has a plurality of mounting holes 731. Preferably, the mounting holes 731 are circular holes. Of course, those skilled in the art will understand that the mounting holes 731 can also be designed in other shapes.

[0104] The pin assembly 8 includes a pin 81, a first ceramic sleeve 82, and a second ceramic sleeve 83. In one embodiment of this application, the pin 81 is made of a metal material. 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.

[0105] During assembly, the first ceramic sleeve 82 is first inserted and passes through the mounting hole 731; then the second ceramic sleeve 83 is at least partially fitted onto the first ceramic sleeve 82, wherein the second ceramic sleeve 83 is located between the heating band 21 and the support frame 7 along the axial direction of the electric heater 100; then the pin 81 passes through the first ceramic sleeve 82 and the second ceramic sleeve 83 and is inserted into the gap hole 22; finally, the pin 81 is fixed to the heating band 21.

[0106] Specifically, the first cylindrical portion 822 is inserted into and passes through the mounting hole 731, and the first base 821 abuts against one side of the support frame 7. The first cylindrical portion 822 is inserted into the second insertion hole 831 of the second ceramic sleeve 83, and the second ceramic sleeve 83 abuts against the other side of the support frame 7. In the embodiment illustrated in this application, the first cylindrical portion 822 is inserted into the second insertion hole 831, but does not protrude from the second ceramic sleeve 83. The pin portion 812 is inserted into and passes through the first insertion hole 8211 and the channel 8221, the pin portion 812 is fixed to the heating band 21, and the abutting portion 811 abuts against the first base 821.

[0107] The pin portion 812 is welded to the heating band 21. In one embodiment of this application, the pin portion 812 is brazed to the heating band 21.

[0108] The second ceramic sleeve 83 is tightly held between the heating band 21 and the support frame 7 along the axial direction of the electric heater 100, so as to control the axial distance between the heating band 21 and the support frame 7 along the electric heater 100.

[0109] The electric heater 100 of this application includes a first connecting block 5, which has a first fixing hole 513; the first electrode assembly 3 includes a first electrode 31, which has a first fixing part 313, and the first fixing part 313 is 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.

[0110] 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.

[0111] 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.

[0112] Compared to existing technologies, the electric heater 100 of this application includes a heating band assembly 2, a support frame 7, and a plurality of pin assemblies 8. The pin assemblies 8 fix the heating band 21 to the support frame 7 along the axial direction of the electric heater 100. The pin assembly 8 includes a first ceramic sleeve 82, a second ceramic sleeve 83, and a pin 81. The first ceramic sleeve 82 is inserted into and passes through the mounting hole 731. The second ceramic sleeve 83 is at least partially fitted onto the first ceramic sleeve 82 and is located between the heating band 21 and the support frame 7 along the axial direction of the electric heater 100. The pin 81 passes through the first ceramic sleeve 82 and the second ceramic sleeve 83 and is inserted into the gap hole 22. The pin 81 is fixed to the heating band 21. With this configuration, the second ceramic sleeve 83 of this application can limit the distance between the heating band 21 and the support frame 7; the pin assembly 8 achieves both fixing of the heating band 21 and insulation from the support frame 7.

[0113] 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), characterized in that, include: A housing (1), the housing (1) including a mounting space (10); A heating band assembly (2) is located at least partially in the mounting space (10). The heating band assembly (2) includes several layers of heating bands (21), which are stacked and wound together to form a disc. Each layer of heating band (21) includes a corrugated portion (210). The heating band assembly (2) also includes several gap holes (22) located between adjacent layers of heating bands (21). The first electrode assembly (3) is electrically connected directly or indirectly to one end of the heating belt assembly (2); The second electrode assembly (4) is electrically connected directly or indirectly to the other end of the heating band assembly (2); A support frame (7), at least partially located in the mounting space (10), the support frame (7) having a plurality of mounting holes (731); and A plurality of pin assemblies (8) are provided, wherein the pin assemblies (8) fix the heating band (21) to the support frame (7) along the axial direction of the electric heater (100); The pin assembly (8) includes a first ceramic sleeve (82), a second ceramic sleeve (83), and a pin (81); the first ceramic sleeve (82) is inserted into and passes through the mounting hole (731), the second ceramic sleeve (83) is at least partially sleeved on the first ceramic sleeve (82), the second ceramic sleeve (83) is located between the heating band (21) and the support frame (7) along the axial direction of the electric heater (100), the pin (81) passes through the first ceramic sleeve (82) and the second ceramic sleeve (83) and is inserted into the gap hole (22), and the pin (81) is fixed to the heating band (21).

2. The electric heater (100) as described in claim 1, characterized in that: 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) is provided with a first insertion hole (8211), and the first cylindrical portion (822) is provided with a channel (8221) communicating with the first insertion hole (8211). The first cylindrical portion (822) is inserted into and passes through the mounting hole (731), and the first base (821) abuts against one side of the support frame (7). The second ceramic sleeve (83) includes a second insertion hole (831), the first cylindrical portion (822) is inserted into the second insertion hole (831), and the second ceramic sleeve (83) abuts against the other side of the support frame (7); The pin (81) includes an abutment portion (811) and a pin portion (812) connected to the abutment portion (811). The pin portion (812) is inserted into and passes through the first socket (8211) and the channel (8221). The pin portion (812) is fixed to the heating band (21). The abutment portion (811) abuts against the first base portion (821).

3. The electric heater (100) as described in claim 2, characterized in that: The insertion pin (812) is welded and fixed to the heating band (21).

4. The electric heater (100) as described in claim 3, characterized in that: The pin portion (812) is brazed and fixed to the heating band (21).

5. The electric heater (100) as claimed in claim 1, characterized in that: The second ceramic sleeve (83) is tightly held between the heating band (21) and the support frame (7) along the axial direction of the electric heater (100).

6. The electric heater (100) as claimed in claim 1, characterized in that: The first cylindrical part (822) is inserted into the second insertion hole (831), but does not protrude from the second ceramic sleeve (83).

7. The electric heater (100) as claimed in claim 1, characterized in that: Each layer of heating band (21) includes a first extension (211) connected to one end of the wave section (210) and a second extension (212) connected to the other end of the wave section (210); The electric heater (100) also includes: A first connecting block (5), the first connecting block (5) having a plurality of first mounting slots (524), the first extension (211) being at least partially received in the first mounting slots (524); and The second connecting block (6) is provided with a plurality of second mounting slots (624), and the second extension (212) is at least partially received in the second mounting slots (624); The first electrode assembly (3) includes a first electrode (31), which is connected to the first connecting block (5); The second electrode assembly (4) includes a second electrode (41), which is connected to the second connecting block (6); One of the first electrode (31) and the second electrode (41) is a positive electrode, and the other is a negative electrode.

8. The electric heater (100) as claimed in claim 7, characterized in that: Each first extension (211) is in the shape of a straight strip; and / or Each second extension (212) is in the shape of a straight strip.

9. The electric heater (100) as claimed in claim 7, characterized in that: Each first extension (211) is in the shape of a straight strip, and the first extensions (211) of the plurality of heating strips (21) are parallel to each other; the plurality of first mounting grooves (524) of the first connecting block (5) are parallel to each other; Each second extension (212) is in the shape of a straight strip, and the second extensions (212) of the plurality of heating bands (21) are parallel to each other; the plurality of second mounting grooves (624) of the second connecting block (6) are parallel to each other; The first extensions (211) of the plurality of heating bands (21) are arranged at equal intervals; the first mounting grooves (524) of the first connecting block (5) are arranged at equal intervals; The second extensions (212) of the plurality of heating bands (21) are arranged at equal intervals; the second mounting grooves (624) of the second connecting block (6) are arranged at equal intervals.

10. A tail gas aftertreatment device, characterized in that, include: Intake assembly (200); An electric heater (100) located downstream of the air intake assembly (200) along the airflow direction; A first exhaust gas aftertreatment module (300) located downstream of the electric heater (100) along the airflow direction; A second exhaust gas aftertreatment module (400) located downstream of the first exhaust gas aftertreatment module (300) along the airflow direction; A mixer assembly (500) located downstream of the second exhaust gas aftertreatment module (400) along the airflow direction; A third exhaust gas aftertreatment module (700) located downstream of the mixer assembly (500) along the airflow direction; as well as An exhaust assembly (800) located downstream of the third exhaust gas aftertreatment module (700) along the airflow direction; The electric heater (100) is the electric heater (100) as described in any one of claims 1 to 9.

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