Electric heater and tail gas aftertreatment device

Abstract

An electric heater comprises a shell, a heating belt assembly, a first electrode assembly, a second electrode assembly, a supporting frame and a plurality of pin assemblies. And the support frame is provided with a plurality of mounting through holes. The contact pin assembly fixes the heating belt to the supporting frame in the axial direction of the electric heater. The pin assembly comprises a first ceramic sleeve, a second ceramic sleeve and a pin. And the first ceramic sleeve is inserted into and penetrates through the mounting through hole. And the second ceramic sleeve is at least partially sleeved on the first ceramic sleeve. And the contact pin penetrates through the first ceramic sleeve and the second ceramic sleeve and is inserted into the clearance hole, and the contact pin is fixed with the heating tape. By means of the arrangement, the heating belt is fixed through the pin assembly, and meanwhile insulation between the pin assembly and the supporting frame is achieved. In addition, the invention also discloses a tail gas after-treatment device comprising the electric heater.

Description

Background Art

[0002] The exhaust gas aftertreatment device in the related art generally includes at least one exhaust gas aftertreatment component. The exhaust gas aftertreatment component includes a shell and an exhaust gas aftertreatment carrier encapsulated in the shell. The exhaust gas aftertreatment carrier has an operating temperature range, that is, only when the temperature reaches the operating temperature range, the exhaust gas aftertreatment carrier has the best working efficiency.

[0003] With the continuous upgrading of emission regulations, higher and higher requirements are put forward for exhaust gas after-treatment devices, especially when the engine is cold started, the exhaust gas temperature is low and cannot reach the working temperature of the exhaust gas after-treatment carrier. At this time, the exhaust gas after-treatment carrier does not work or its conversion efficiency is extremely low, which is easy to cause emission pollution and other problems.

[0004] Therefore, how to shorten the time to reach the working temperature of the exhaust gas aftertreatment carrier as much as possible is a technical problem faced by technicians in the relevant technical field.

[0005] 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 aftertreatment carrier. It is one of the important technical means in the industry.

[0006] The electric heater generally comprises a housing, a heating element, an electrode, 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 technicians in the relevant technical field. Summary of the invention

[0007] The object of the present invention is to provide an electric heater and an exhaust gas after-treatment device with improved structures.

[0008] To achieve the above object, the present invention adopts the following technical solution: an electric heater, comprising:

[0009] A housing, the housing comprising an installation space;

[0010] A heating belt assembly, wherein the heating belt assembly is at least partially located in the installation space, the heating belt assembly comprises a plurality of layers of heating belts, the plurality of layers of heating belts are stacked and wound to form a disc, and each layer of the heating belts comprises a wave portion; the heating belt assembly further comprises a plurality of gap holes between two adjacent layers of the heating belts;

[0011] A first electrode assembly, wherein the first electrode assembly is directly or indirectly electrically connected to one end of the heating belt assembly;

[0012] A second electrode assembly, the second electrode assembly being directly or indirectly electrically connected to the other end of the heating belt assembly;

[0013] a support frame, the support frame being at least partially located in the installation space, the support frame being provided with a plurality of installation through holes; and

[0014] A plurality of pin assemblies, wherein the pin assemblies fix the heating belt to the support frame along the axial direction of the electric heater;

[0015] 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 installation through hole, the second ceramic sleeve is at least partially sleeved on the first ceramic sleeve, the second ceramic sleeve is located between the heating belt 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 belt.

[0016] As a further improved technical solution of the present invention, the first ceramic sleeve includes a first base and a first cylindrical portion connected to the first base, the first base is provided with a first plug hole, and the first cylindrical portion is provided with a channel connected to the first plug hole; the first cylindrical portion is inserted into and passes through the mounting through hole, and the first base abuts against one side of the support frame;

[0017] The second ceramic sleeve comprises 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;

[0018] The insertion pin includes an abutment portion and an insertion pin portion connected to the abutment portion, the insertion pin portion is inserted into and passes through the first insertion hole and the channel, the insertion pin portion is fixed to the heating belt, and the abutment portion abuts against the first base.

[0019] As a further improved technical solution of the present invention, the pin portion is fixed to the heating belt by welding.

[0020] As a further improved technical solution of the present invention, the pin portion is fixed to the heating belt by brazing.

[0021] As a further improved technical solution of the present invention, the second ceramic sleeve is tightly clamped between the heating belt and the support frame along the axial direction of the electric heater.

[0022] As a further improved technical solution of the present invention, the first cylindrical portion is inserted into the second insertion hole but does not pass through the second ceramic sleeve.

[0023] As a further improved technical solution of the present invention, each layer of the heating belt includes a first extension portion connected to one end of the wave portion and a second extension portion connected to the other end of the wave portion;

[0024] The electric heater also includes:

[0025] A first connecting block, wherein the first connecting block is provided with a plurality of first mounting grooves, and the first extension portion is at least partially received in the first mounting grooves; and

[0026] a second connecting block, the second connecting block being provided with a plurality of second mounting grooves, the second extension portion being at least partially received in the second mounting grooves;

[0027] The first electrode assembly includes a first electrode, and the first electrode is connected to the first connection block;

[0028] The second electrode assembly includes a second electrode, and the second electrode is connected to the second connection block;

[0029] One of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0030] As a further improved technical solution of the present invention, each first extension portion is in the shape of a straight strip; and / or

[0031] Each second extension portion is in a straight bar shape.

[0032] As a further improved technical solution of the present invention, each first extension portion is in a straight strip shape, the first extension portions of the plurality of layers of heating belts are parallel to each other; the plurality of first installation grooves of the first connecting block are parallel to each other;

[0033] Each second extension portion is in a straight strip shape, and the second extension portions of the plurality of layers of heating belts are parallel to each other; and the plurality of second installation grooves of the second connecting block are parallel to each other;

[0034] The first extension portions of the plurality of layers of heating belts are arranged at equal intervals; the first installation grooves of the first connecting blocks are arranged at equal intervals;

[0035] The second extension portions of the plurality of layers of heating belts are arranged at equal intervals; and the second installation grooves of the second connecting blocks are arranged at equal intervals.

[0036] The present invention also discloses an exhaust gas post-treatment device, which comprises:

[0037] Air intake assembly;

[0038] an electric heater located downstream of the air intake assembly along the air flow direction;

[0039] a first exhaust gas after-treatment module located downstream of the electric heater along the airflow direction;

[0040] a second exhaust gas after-treatment module located downstream of the first exhaust gas after-treatment module along the airflow direction;

[0041] a mixer assembly located downstream of the second exhaust gas after-treatment module along the airflow direction;

[0042] a third exhaust gas after-treatment module located downstream of the mixer assembly along the air flow direction; and

[0043] an air outlet component located downstream of the third exhaust gas after-treatment module along the airflow direction;

[0044] Wherein, the electric heater is the aforementioned electric heater.

[0045] Compared with the prior art, the electric heater of the present invention includes a heating belt assembly, a support frame and a plurality of pin assemblies, wherein the pin assembly fixes the heating belt to the support frame along the axial direction of the electric heater; 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 installation through-hole, the second ceramic sleeve is at least partially sleeved on the first ceramic sleeve, the second ceramic sleeve is located between the heating belt 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 belt. With such a configuration, the second ceramic sleeve of the present invention can limit the distance between the heating belt and the support frame; the pin assembly achieves insulation from the support frame while achieving fixation of the heating belt. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the principle of the exhaust gas after-treatment device of the present invention.

[0047] Figure 2 It is a three-dimensional schematic diagram of an electric heater of the present invention in one embodiment.

[0048] Figure 3 yes Figure 2 A three-dimensional diagram from another angle.

[0049] Figure 4 yes Figure 2 main view.

[0050] Figure 5 yes Figure 3 main view.

[0051] Figure 6 yes Figure 4 A partial enlarged view of the middle frame portion A.

[0052] Figure 7 yes Figure 4 A partial enlarged view of the middle frame portion B.

[0053] Figure 8 yes Figure 2 Left view of .

[0054] Fig. 9 is along Figure 8 Schematic diagram of the cross section along the CC line.

[0055] Fig.10 yes Figure 2 A partially exploded perspective view of the present invention, wherein the first electrode assembly and the second electrode assembly are separated.

[0056] Fig.11 yes Fig.10 Partial three-dimensional exploded view from another angle.

[0057] Fig.12 yes Fig.10 Partial exploded view of the .

[0058] Fig.13 yes Fig.12 Partial three-dimensional exploded view from another angle.

[0059] Fig.14 yes Fig.12 Further exploded view.

[0060] Fig.15 It is a three-dimensional schematic diagram of a pin assembly.

[0061] Fig.16 yes Fig.15 3D exploded view of .

[0062] Fig.17 yes Fig.15 A three-dimensional diagram from another angle.

[0063] Fig.18 yes Fig.17 3D exploded view of .

[0064] Fig.19 It is a three-dimensional exploded view of the first connecting block, the second connecting block, the heating belt assembly, the first electrode assembly and the second electrode assembly.

[0065] Fig. 20 It 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.

[0066] Fig.21 yes Fig. 20 Rear view of.

[0067] Fig. 22 yes Fig. 20 A partial enlarged view of the circled portion D.

[0068] Fig.23 yes Fig. 20 A partial enlarged view of the circled portion E.

[0069] Fig.24 is along Figure 4 Schematic diagram of the cross section of the FF line. DETAILED DESCRIPTION

[0070] The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, where if there are several specific embodiments, the features of these embodiments can be combined with each other without conflict. When the description refers to the drawings, unless otherwise specified, the same numbers or symbols in different drawings represent the same or similar elements. The contents described in the following exemplary specific embodiments do not represent all embodiments of the present invention. On the contrary, they are only examples of products consistent with the present invention as recorded in the claims of the present invention.

[0071] The terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. It should be understood that the words "first", "second" and the like used in the specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish the names of features.

[0072] Please refer to Figure 1 As shown, the present invention discloses an exhaust gas after-treatment device, which includes an air intake component 200, an electric heater 100 located downstream of the air intake component 200 along the air flow direction, a first exhaust gas after-treatment module 300 (for example, a diesel oxidation catalyst, DOC) located downstream of the electric heater 200 along the air flow direction, a second exhaust gas after-treatment module 400 (for example, a diesel particulate filter, DPF) located downstream of the first exhaust gas after-treatment module 300 along the air flow direction, a mixer component 500 located downstream of the second exhaust gas after-treatment module 400 along the air flow direction, a urea nozzle 600 installed on the mixer component 500, a third exhaust gas after-treatment module 700 (for example, a selective catalytic reduction, SCR) located downstream of the mixer component 500 along the air flow direction, and an exhaust component 800 located downstream of the third exhaust gas after-treatment module 700 along the air flow direction. The first exhaust gas post-processing module 300, the second exhaust gas post-processing module 400 and the third exhaust gas post-processing module 700 are collectively referred to as exhaust gas post-processing modules. Figure 1 As shown, the airflow direction is Figure 1 The hollow arrow points to the direction.

[0073] Please combine Figures 2 to 24As shown, the illustrated embodiment of the present invention discloses an electric heater 100, which is used in the exhaust gas after-treatment device, and the electric heater 100 includes a shell 1, a heating belt assembly 2 at least partially located in the shell 1, a first electrode assembly 3 installed on the shell 1, a second electrode assembly 4 installed on the shell 1, a first connecting block 5 connecting one end of the heating belt assembly 2 with the first electrode assembly 3, a second connecting block 6 connecting the other end of the heating belt assembly 2 with the second electrode assembly 4, a support frame 7 at least partially located in the shell 1, and a plurality of pin assemblies 8 fixing the heating belt assembly 2 to the support frame 7 along the axial direction of the electric heater 100.

[0074] In the illustrated embodiment of the present invention, the housing 1 is made of a metal material, for example, a stainless steel material. The housing 1 is roughly in the shape of a hollow cylinder, and the housing 1 is provided with an installation space 10. The housing 1 includes an outer surface 11 and an inner surface 12 opposite to the outer surface 11, and the inner surface 12 is exposed to the installation space 10. The housing 1 also includes a first installation hole 13 that passes through the outer surface 11 and the inner surface 12 and is connected to the installation space 10, and a second installation hole 14 that passes through the outer surface 11 and the inner surface 12 and is connected to the installation space 10. In the illustrated embodiment of the present invention, the first installation hole 13 and the second installation hole 14 are both circular perforations. Of course, a person skilled in the art can understand that in other embodiments of the present invention, the first installation hole 13 and the second installation hole 14 can also be other shapes, including but not limited to elliptical holes, waist-shaped holes, rectangular holes, trapezoidal holes, triangular holes, etc., and the present invention will not repeat them. In addition, in the illustrated embodiment of the present invention, the outer surface 11 and the inner surface 12 are both arc-shaped surfaces. Of course, those skilled in the art will appreciate that, in other embodiments of the present invention, the outer surface 11 and the inner surface 12 may also be planes.

[0075] In the illustrated embodiment of the present invention, the heating belt assembly 2 includes several layers of heating belts 21 made of metal material. In the illustrated embodiment of the present invention, the heating belt assembly 2 includes seven layers of heating belts 21, wherein each layer of the heating belt 21 includes 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 wavy, and is provided with crests and troughs. The heating belts 21 of two adjacent layers are fixed together. In one embodiment of the present invention, the heating belts 21 of two adjacent layers are fixed together by brazing. It can be understood by those skilled in the art that the two adjacent layers of the heating belts 21 can be fixed together in various ways, for example, the crest of one heating belt 21 is fixed to the crest of an adjacent heating belt 21; or the crest of one heating belt 21 is fixed to the trough of an adjacent heating belt 21; or the trough of one heating belt 21 is fixed to the trough of an adjacent heating belt 21. The heating belt assembly 2 includes a plurality of gap holes 22 between two adjacent layers of heating belts 21. Most of the plurality of gap holes 22 are used to allow exhaust gas to flow through, so that the heating belt assembly 2 is used to heat the exhaust gas.

[0076] Those skilled in the art will appreciate that the crests of each layer of the heating belt 21 may be the same or different, and the troughs of each layer of the heating belt 21 may be the same or different. The crests of two adjacent layers of the heating belt 21 may be the same or different, and the troughs of two adjacent layers of the heating belt 21 may be the same or different.

[0077] In the illustrated embodiment of the present invention, the plurality of layers of heating belts 21 are stacked and wound to form a disc. The heating belt assembly 2 includes a plurality of layers from the inside to the outside in the radial direction, wherein a gap 23 is provided between the inner layer of the heating belt assembly 2 and the outer layer of the heating belt assembly 2. The gap 23 is used to allow the exhaust gas to flow through, so that the exhaust gas is heated by the heating belt assembly 2.

[0078] In the illustrated embodiment of the present invention, preferably, the length of each layer of the heating belt 21 is the same, so as to distribute the current evenly to each heating belt 21 as much as possible. In the illustrated embodiment of the present invention, the first extension portion 211 and the second extension portion 212 are both roughly in the shape of straight strips. Those skilled in the art can understand that the technology used in the present invention belongs to the "straight strip" does not require it to be completely flat and completely straight, and appropriate bending is also possible. In one embodiment of the present invention, the first extension portion 211 and the second extension portion 212 can even be arranged obliquely relative to the wave portion 210. In the illustrated embodiment of the present invention, the plurality of layers of heating belts 21 include a first end 24 composed of the plurality of first extension portions 211 and a second end 25 composed of the plurality of second extension portions 212. In the illustrated embodiment of the present invention, the plurality of first extension portions 211 of the first end 24 are parallel to each other, and the plurality of second extension portions 212 of the second end 25 are also parallel to each other.

[0079] Preferably, in one embodiment of the present invention, the distance between any two adjacent first extension portions 211 of the plurality of first extension portions 211 is equal, in other words, the plurality of first extension portions 211 are arranged at equal intervals. Compared with the design in which the plurality of first extension portions 211 are stacked and squeezed together, this arrangement is less likely to cause heat concentration after power is turned on, thereby reducing the risk of excessive local temperature.

[0080] Similarly, in one embodiment of the present invention, the distance between any two adjacent second extensions 212 in the plurality of second extensions 212 is equal, in other words, the plurality of second extensions 212 are arranged at equal intervals. Compared with the design in which the plurality of second extensions 212 are stacked and squeezed together, this arrangement is less likely to cause heat concentration after power is turned on, thereby reducing the risk of excessive local temperature.

[0081] The first connection block 5 is made of metal material, 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 on the inner side of 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 that passes through the first surface 511 and the second surface 512 and is connected to the first clearance space 53. In one embodiment of the present invention, the first fixing hole 513 is an internal threaded hole. The first fixing hole 513 corresponds to the first mounting hole 13. In the illustrated embodiment of the present invention, the size of the first mounting hole 13 is larger than the size of the first fixing hole 513, so as to facilitate the first electrode assembly 3 to pass through the first mounting hole 13 during assembly.

[0082] 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 illustrated embodiment of the present invention, the first mounting groove 524 penetrates the first side surface 521 and the second side surface 522 along the axial direction of the electric heater 100. The first mounting groove 524 is used to accommodate the first extension portion 211. In order to improve the elasticity of the installation, the length of the first mounting groove 524 is greater than the length of the first extension portion 211. The design of accommodating the first extension portion 211 in the first mounting groove 524 is conducive to increasing the contact area between the first extension portion 211 and the first connecting block 5, and is conducive to improving the connection stability between the two.

[0083] Similarly, the second connection block 6 is made of a metal material, 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 on the inner side of 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 that passes through the third surface 611 and the fourth surface 612 and is connected to the second clearance space 63. In one embodiment of the present invention, the second fixing hole 613 is an internal threaded hole. The second fixing hole 613 corresponds to the second mounting hole 14. In the illustrated embodiment of the present invention, the size of the second mounting hole 14 is larger than the size of the second fixing hole 613, so as to facilitate the second electrode assembly 4 to pass through the second mounting hole 14 during assembly.

[0084] 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 illustrated embodiment of the present invention, the second mounting groove 624 penetrates the third side surface 621 and the fourth side surface 622 along the axial direction of the electric heater 100. The second mounting groove 624 is used to accommodate the second extension portion 212. In order to improve the elasticity of the installation, the length of the second mounting groove 624 is greater than the length of the second extension portion 212. The design of accommodating the second extension portion 212 in the second mounting groove 624 is conducive to increasing the contact area between the second extension portion 212 and the second connecting block 6, and is conducive to improving the connection stability between the two.

[0085] 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 the present invention, the first electrode 31 includes a first main body 311, a first transition portion 312 connected to one end of the first main body 311, a first fixing portion 313 connected to the other end of the first main body 311, and a first external threaded portion 314 connected to the first transition portion 312. In the illustrated embodiment of the present invention, the first external threaded portion 314, the first transition portion 312, the first main body 311, and the first fixing portion 313 are connected in sequence. In the illustrated embodiment of the present invention, the outer diameter of the first main body 311 is greater than the outer diameter of the first external threaded portion 314. The first transition portion 312 is truncated cone-shaped, and includes a large diameter end connected to the first main body 311 and a small diameter end connected to the first external threaded portion 314, so that the first main body 311, the first transition portion 312, and the first external threaded portion 314 change gradually. An outer diameter of the first fixing portion 313 is smaller than an outer diameter of the first main body portion 311 .

[0086] In the illustrated embodiment of the present invention, the first insulating portion 32 is a ceramic sleeve, which is sleeved on the first main body 311 to insulate the first electrode 31 from the first shielding portion 33. The first shielding portion 33 is provided with a first through hole 330, and the first insulating portion 32 is fixed in the first through hole 330 in an interference fit manner.

[0087] Of course, those skilled in the art will understand that the first insulating portion 32 is also an insulating coating (such as a ceramic coating) plated on the first main body portion 311 , which can also play an insulating role, and the present invention will not elaborate on this.

[0088] In the illustrated embodiment of the present invention, 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. In addition, in order 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 further provided inside the first shielding portion 33 to reduce heat transfer through air as quickly as possible. In the illustrated embodiment of the present invention, the first clearance hole 331 is generally conical, and the diameter of the hole at one end of the radial direction close to the heating belt assembly 2 is larger than the diameter of the hole at one end away from the heating belt assembly 2.

[0089] In the illustrated embodiment of the present invention, the first shielding portion 33 is provided with a first force-applying portion 332 . The first force-applying portion 332 is a hexagonal nut including six outer side surfaces.

[0090] In the illustrated embodiment of the present invention, the first electrode 31, the first insulating portion 32 and the first shielding portion 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 illustrated embodiment of the present invention, the aperture 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, so that the first electrode assembly 3 can pass through the first mounting hole 13 more easily. This design is conducive to improving the elasticity of installation and improving the convenience of installation. The first fixing portion 313 passes through the first mounting hole 13 and is fixed in the first fixing hole 513. In one embodiment of the present invention, the first fixing portion 313 is provided with an external thread (not shown), and the external thread of the first fixing portion 313 matches the internal thread of the first fixing hole 513. The external thread of the first fixing portion 313 and the internal thread of the first fixing hole 513 can be tightened by the hexagonal nut and with the help of the matching installation tool. When the first electrode assembly 3 is installed in place, the first shielding portion 33 is located between the first electrode 31 and the first shielding portion 33 , and the first shielding portion 33 extends through the first installation hole 13 and the first clearance hole 331 , and at least partially extends into the installation space 10 .

[0091] Of course, those skilled in the art will appreciate that the first shielding portion 33 may not be provided with the first force applying portion 332. At this time, when the first electrode assembly 3 is installed on the first connecting block 5, the first external thread portion 314 may be used to tighten the external thread of the first fixing portion 313 and the internal thread of the first fixing hole 513 using an installation tool.

[0092] In the illustrated embodiment of the present invention, the first fixing portion 313 protrudes from the second surface 512 to facilitate observation of the installation. The first fixing portion 313 partially protrudes into the first clearance space 53, but the end of the first fixing portion 313 and the heating belt assembly 2 directly opposite to it still maintain an appropriate safety distance to avoid direct contact between the end of the first fixing portion 313 and the heating belt assembly 2 directly opposite to it. It can be understood by those skilled in the art that the present invention, by providing the first clearance space 53, is conducive to reducing the risk of direct contact between the end of the first fixing portion 313 and the heating belt assembly 2 directly opposite to it.

[0093] Compared with the related art, the present invention realizes the connection and fixation between the first electrode 31 and the first connecting block 5 by mechanical connection, thereby avoiding the damage to the first electrode 31 caused by the high temperature generated during the welding connection.

[0094] 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 the present invention, the second electrode 41 includes a second main body 411, a second transition portion 412 connected to one end of the second main body 411, a second fixing portion 413 connected to the other end of the second main body 411, and a second external threaded portion 414 connected to the second transition portion 412. In the illustrated embodiment of the present invention, the second external threaded portion 414, the second transition portion 412, the second main body 411, and the second fixing portion 413 are connected in sequence. In the illustrated embodiment of the present invention, the outer diameter of the second main body 411 is greater than the outer diameter of the second external threaded portion 414. The second transition portion 412 is truncated cone-shaped, and includes a large diameter end connected to the second main body 411 and a small diameter end connected to the second external threaded portion 414, so that the second main body 411, the second transition portion 412, and the second external threaded portion 414 change gradually. An outer diameter of the second fixing portion 413 is smaller than an outer diameter of the second main body portion 411 .

[0095] In the illustrated embodiment of the present invention, the second insulating portion 42 is a ceramic sleeve, which is sleeved on the second main body 411 to insulate the second electrode 41 from the second shielding portion 43. The second shielding portion 43 is provided with a second through hole 430, and the second insulating portion 42 is fixed in the second through hole 430 in an interference fit manner.

[0096] Of course, those skilled in the art will understand that the second insulating portion 42 is also an insulating coating (such as a ceramic coating) plated on the second main body portion 411 , which can also play an insulating role, and the present invention will not elaborate on this.

[0097] In the illustrated embodiment of the present invention, 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. In addition, in order 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 further provided inside the second shielding portion 43 to reduce heat transfer through air as quickly as possible. In the illustrated embodiment of the present invention, the second clearance hole 431 is generally conical, and the diameter of the hole at one end of the second clearance hole 431 radially close to the heating belt assembly 2 is larger than the diameter of the hole at one end away from the heating belt assembly 2.

[0098] In the illustrated embodiment of the present invention, the second shielding portion 43 is provided with a second force-applying portion 432 . The second force-applying portion 432 is a hexagonal nut including six outer side surfaces.

[0099] In the illustrated embodiment of the present invention, the second electrode 41, the second insulating portion 42 and the second shielding portion 43 are assembled into an integral second electrode assembly 4. Then, the second electrode assembly 4 is passed through the second mounting hole 14. In the illustrated embodiment of the present invention, the aperture 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, so that the second electrode assembly 4 can pass through the second mounting hole 14 more easily. This design is conducive to improving the elasticity of installation and improving the convenience of installation. The second fixing portion 413 passes through the second mounting hole 14 and is fixed in the second fixing hole 613. In one embodiment of the present invention, the second fixing portion 413 is provided with an external thread (not shown), and the external thread of the second fixing portion 413 matches the internal thread of the second fixing hole 613. The external thread of the second fixing portion 413 and the internal thread of the second fixing hole 613 can be tightened by the hexagonal nut and with the help of the matching installation tool. When the second electrode assembly 4 is installed in place, the second shielding portion 43 is located between the second electrode 41 and the second shielding portion 43 , and the second shielding portion 43 extends through the second installation hole 14 and the second clearance hole 431 , and at least partially extends into the installation space 10 .

[0100] Of course, those skilled in the art will appreciate that the second shielding portion 43 may not be provided with the second force applying portion 432. At this time, when the second electrode assembly 4 is installed on the second connecting block 6, the second external thread portion 414 may be used to tighten the external thread of the second fixing portion 413 and the internal thread of the second fixing hole 613 using an installation tool.

[0101] In the illustrated embodiment of the present invention, the second fixing portion 413 protrudes from the fourth surface 612 to facilitate observation of the installation. The second fixing portion 413 partially protrudes into the second clearance space 63, but the end of the second fixing portion 413 and the heating belt assembly 2 directly opposite to it still maintain an appropriate safety distance to avoid direct contact between the end of the second fixing portion 413 and the heating belt assembly 2 directly opposite to it. It can be understood by those skilled in the art that the present invention, by providing the second clearance space 63, is conducive to reducing the risk of direct contact between the end of the second fixing portion 413 and the heating belt assembly 2 directly opposite to it.

[0102] Compared with the related art, the present invention realizes the connection and fixation between the second electrode 41 and the second connecting block 6 by mechanical connection, thereby avoiding the damage to the second electrode 41 caused by the high temperature generated during the welding connection.

[0103] Those skilled in the art will appreciate that one of the first electrode 31 and the second electrode 41 of the present invention is a positive electrode and the other is a negative electrode. Preferably, the first electrode assembly 3 and the second electrode assembly 4 have the same structure so that they can share parts and save costs. Preferably, the first connecting block 5 and the second connecting block 6 have the same structure so that they can share parts and save costs.

[0104] The support frame 7 is made of metal material. The support frame 7 includes 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. The outer edge portion 72 is provided with 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 the exhaust gas to flow through, reducing the shielding 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 portion 71 is in the shape of a frame surrounded by the periphery to increase the structural strength.

[0105] Those skilled in the art will appreciate that, in general, in order to improve the structural strength, the outer edge portion 72 is designed as an integral outer frame structure. However, this design causes the outer frame structure to block the first electrode assembly 3 and the second electrode assembly 4, which is not conducive to heat dissipation. The present invention innovatively designs the first notch 721 and the second notch 722 to solve the risk of overheating of the first electrode 31 and the second electrode 41 due to being blocked by the outer edge portion 72.

[0106] In the illustrated embodiment of the present invention, the outer edge portion 72 is welded and fixed to the inner surface 12 of the shell 1 to be fixed to the shell 1 .

[0107] The inner edge 71 and the outer edge 72 are connected by the spokes 73, and the spokes 73 can play a role in strengthening the structural strength. In the illustrated embodiment of the present invention, each spoke 73 is provided with 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.

[0108] The pin assembly 8 includes a pin 81, a first ceramic sleeve 82 and a second ceramic sleeve 83. In one embodiment of the present invention, 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 is provided with a first plug hole 8211, and the first cylindrical portion 822 is provided with a channel 8221 connected to the first plug hole 8211. The second ceramic sleeve 83 includes a second plug hole 831.

[0109] During assembly, first insert the first ceramic sleeve 82 into and pass through the mounting through-hole 731; then at least partially sleeve the second ceramic sleeve 83 on the first ceramic sleeve 82, wherein the second ceramic sleeve 83 is located between the heating belt 21 and the support frame 7 along the axial direction of the electric heater 100; then pass the plug pin 81 through the first ceramic sleeve 82 and the second ceramic sleeve 83 and insert it into the gap hole 22; finally, fix the plug pin 81 to the heating belt 21.

[0110] Specifically, the first cylindrical portion 822 is inserted into and passes through the mounting through hole 731, and the first base portion 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 illustrated embodiment of the present invention, the first cylindrical portion 822 is inserted into the second insertion hole 831, but does not pass through 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 belt 21, and the abutting portion 811 abuts against the first base portion 821.

[0111] The pin portion 812 is fixed to the heating belt 21 by welding. In one embodiment of the present invention, the pin portion 812 is fixed to the heating belt 21 by brazing.

[0112] The second ceramic sleeve 83 is tightly clamped between the heating belt 21 and the support frame 7 along the axial direction of the electric heater 100 to control the axial distance between the heating belt 21 and the support frame 7 along the electric heater 100 .

[0113] The electric heater 100 of the present invention includes a first connecting block 5, which is provided with a first fixing hole 513; the first electrode assembly 3 includes a first electrode 31, which is provided with a first fixing portion 313, and the first fixing portion 313 is connected to the first fixing hole 513 by threaded cooperation; such an arrangement avoids the structural reliability problems that may be caused by direct welding of the first electrode 31 and the heating belt assembly 2, thereby improving durability.

[0114] Similarly, the electric heater 100 of the present invention includes a second connecting block 6, which is provided with a second fixing hole 613; the second electrode assembly 4 includes a second electrode 41, which is provided with a second fixing portion 413, and the second fixing portion 413 is connected to the second fixing hole 613 by threaded fitting; such an arrangement avoids structural reliability problems that may be caused by direct welding of the second electrode 41 and the heating belt assembly 2, thereby improving durability.

[0115] In addition, the present invention provides the first connecting block 5 and the second connecting block 6 with the above structure, utilizes the first mounting groove 524 on the first connecting block 5 to accommodate the first extension portion 211, and utilizes the second mounting groove 624 on the second connecting block 6 to accommodate the second extension portion 212, which is beneficial for relatively evenly distributing the current to each layer of the heating belt 21 through the first connecting block 5 and the second connecting block 6, thereby facilitating improving the temperature uniformity of the electric heater 100 and reducing the risk of local overheating.

[0116] Compared with the prior art, the electric heater 100 of the present invention comprises a heating belt assembly 2, a support frame 7 and a plurality of pin assemblies 8, wherein the pin assembly 8 fixes the heating belt 21 to the support frame 7 along the axial direction of the electric heater 100; the pin assembly 8 comprises 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 through 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 belt 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 belt 21. With such a configuration, the second ceramic sleeve 83 of the present invention can limit the distance between the heating belt 21 and the support frame 7; the pin assembly 8 achieves insulation from the support frame 7 while achieving fixation of the heating belt 21.

[0117] The above embodiments are only used to illustrate the present invention but not to limit the technical solutions described in the present invention. The understanding of this specification should be based on the technicians in the relevant technical field. Although this specification has described the present invention in detail with reference to the above embodiments, ordinary technicians in the field should understand that technicians in the relevant technical field can still modify or replace the present invention with equivalents, and all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. An electric heater (100), characterized in that: include: A housing (1), the housing (1) comprising an installation space (10); A heating belt assembly (2), wherein the heating belt assembly (2) is at least partially located in the installation space (10), the heating belt assembly (2) comprises a plurality of layers of heating belts (21), the plurality of layers of heating belts (21) are stacked on top of each other and wound to form a disc shape, and each layer of the heating belts (21) comprises a wave portion (210); the heating belt assembly (2) further comprises a plurality of gap holes (22) located between two adjacent layers of the heating belts (21); A first electrode assembly (3), the first electrode assembly (3) being electrically connected directly or indirectly to one end of the heating belt assembly (2); A second electrode assembly (4), the second electrode assembly (4) being directly or indirectly electrically connected to the other end of the heating belt assembly (2); A support frame (7), wherein the support frame (7) is at least partially located in the installation space (10), and the support frame (7) is provided with a plurality of installation through holes (731); and a plurality of pin assemblies (8), wherein the pin assemblies (8) fix the heating belt (21) to the support frame (7) along the axial direction of the electric heater (100); The pin assembly (8) comprises 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 through 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 belt (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 belt (21).

2. The electric heater (100) according to claim 1, characterized in that: The first ceramic sleeve (82) comprises 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) connected to the first insertion hole (8211); the first cylindrical portion (822) is inserted into and passes through the mounting through hole (731), and the first base (821) abuts against one side of the support frame (7); The second ceramic sleeve (83) comprises 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 insertion pin (81) comprises an abutment portion (811) and an insertion pin portion (812) connected to the abutment portion (811); the insertion pin portion (812) is inserted into and passes through the first insertion hole (8211) and the channel (8221); the insertion pin portion (812) is fixed to the heating belt (21); and the abutment portion (811) abuts against the first base portion (821).

3. The electric heater (100) according to claim 2, characterized in that: The pin portion (812) is fixed to the heating belt (21) by welding.

4. The electric heater (100) according to claim 3, characterized in that: The pin portion (812) is fixed to the heating belt (21) by brazing.

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

6. The electric heater (100) according to claim 1, characterized in that: The first cylindrical portion (822) is inserted into the second insertion hole (831) but does not pass through the second ceramic sleeve (83).

7. The electric heater (100) according to claim 1, characterized in that: Each layer of the heating belt (21) comprises 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 electric heater (100) further comprises: A first connecting block (5), the first connecting block (5) being provided with a plurality of first mounting grooves (524), the first extending portion (211) being at least partially received in the first mounting grooves (524); and A second connecting block (6), wherein the second connecting block (6) is provided with a plurality of second mounting grooves (624), and the second extension portion (212) is at least partially received in the second mounting grooves (624); The first electrode assembly (3) comprises a first electrode (31), and the first electrode (31) is connected to the first connecting block (5); The second electrode assembly (4) comprises a second electrode (41), and the second electrode (41) 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) according to claim 7, characterized in that: Each first extension portion (211) is in the shape of a straight bar; and / or Each second extension portion (212) is in the shape of a straight bar.

9. The electric heater (100) according to claim 7, characterized in that: Each first extension portion (211) is in the shape of a straight strip, and the first extension portions (211) of the plurality of layers of heating belts (21) are parallel to each other; the plurality of first installation grooves (524) of the first connection block (5) are parallel to each other; Each second extension portion (212) is in the shape of a straight strip, and the second extension portions (212) of the plurality of layers of heating belts (21) are parallel to each other; the plurality of second installation grooves (624) of the second connecting block (6) are parallel to each other; The first extension portions (211) of the plurality of layers of heating belts (21) are arranged at equal intervals; the first installation grooves (524) of the first connection blocks (5) are arranged at equal intervals; The second extension portions (212) of the plurality of layers of heating belts (21) are arranged at equal intervals; and the second installation grooves (624) of the second connection blocks (6) are arranged at equal intervals.

10. An exhaust gas post-treatment device, characterized in that: include: Air intake assembly (200); an electric heater (100) located downstream of the air intake assembly (200) along the air flow direction; a first exhaust gas post-processing module (300) located downstream of the electric heater (100) along the airflow direction; a second exhaust gas post-processing module (400) located downstream of the first exhaust gas post-processing module (300) along the airflow direction; a mixer assembly (500) located downstream of the second exhaust gas after-treatment module (400) along the airflow direction; a third exhaust gas after-treatment module (700) located downstream of the mixer assembly (500) along the airflow direction; as well as An air outlet component (800) located downstream of the third exhaust gas post-processing module (700) along the airflow direction; Wherein, the electric heater (100) is the electric heater (100) according to any one of claims 1 to 9.

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