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 pin assembly can fix the heating belt and can be insulated from the supporting frame at the same time. In addition, the utility model also discloses a tail gas after-treatment device comprising the electric heater.

Description

TECHNICAL FIELD

[0001] The utility model relates to an electric heater and tail gas aftertreatment device belong to engine tail gas aftertreatment technical field. BACKGROUND

[0002] The tail gas aftertreatment device in the related art usually comprises at least one tail gas aftertreatment component. The tail gas aftertreatment component comprises a shell and a tail gas aftertreatment carrier encapsulated in the shell. The tail gas aftertreatment carrier has a working temperature range, i.e. only when the temperature reaches the working temperature range, the tail gas aftertreatment carrier has the best working efficiency.

[0003] With the continuous upgrading of emission regulations, higher and higher requirements are put forward for the tail gas aftertreatment device, especially when the engine is cold started, the temperature of the tail gas is low and cannot reach the working temperature of the tail gas aftertreatment carrier. At this time, the tail gas aftertreatment carrier does not work or its conversion efficiency is very 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 tail gas aftertreatment carrier is a technical problem faced by the technical personnel in the technical field.

[0005] The electric heater is a device for heating the tail gas by using electric energy to shorten the time to reach the working temperature of the tail gas aftertreatment carrier, and it is one of the important technical means in the industry.

[0006] The electric heater usually comprises a shell, a heating element, an electrode, a support frame and a pin assembly, wherein the pin assembly is used to fix the heating element and the support frame. However, how to realize the insulation between the support frame and the heating element is a technical problem faced by the technical personnel in the technical field. INVENTION CONTENTS

[0007] The utility model aims at providing an electric heater and tail gas aftertreatment device with improved structure.

[0008] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: an electric heater comprises:

[0009] A shell comprises a mounting space.

[0010] A heating band assembly is at least partially located in the mounting space, and the heating band assembly comprises a plurality of layers of heating bands, the plurality of layers of heating bands are stacked and wound to form a disc shape, and each layer of heating band comprises a wave part; the heating band assembly further comprises a plurality of gap holes between adjacent two layers of heating bands.

[0011] A first electrode assembly is directly or indirectly electrically connected with one end of the heating band assembly;

[0012] A second electrode assembly is directly or indirectly electrically connected with the other end of the heating band assembly;

[0013] A support frame is at least partially located in the mounting space, and the support frame is provided with a plurality of mounting perforations; and

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

[0015] The pin assembly comprises a first ceramic sleeve, a second ceramic sleeve and a pin; the first ceramic sleeve is inserted through the mounting perforation, the second ceramic sleeve is at least partially sleeved on 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 is inserted through the first ceramic sleeve and the second ceramic sleeve and inserted into the gap hole, and the pin is fixed to the heating band.

[0016] As a further improved technical scheme of the utility model, the first ceramic sleeve comprises a first base and a first cylindrical portion connected with the first base, the first base is provided with a first insertion hole, and the first cylindrical portion is provided with a passage in communication with the first insertion hole; the first cylindrical portion is inserted through the mounting perforation, 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 pin comprises an abutting portion and a pin portion connected with the abutting portion, the pin portion is inserted through the first insertion hole and the passage, the pin portion is fixed to the heating band, and the abutting portion abuts against the first base.

[0019] As a further improved technical scheme of the utility model, the pin portion is welded to the heating band.

[0020] As a further improved technical scheme of the utility model, the pin portion is brazed to the heating band.

[0021] As a further improved technical scheme of the utility model, the second ceramic sleeve is tightly clamped between the heating band and the support frame along the axial direction of the electric heater.

[0022] As a further improved technical scheme of the utility model, the first cylindrical part is inserted into the second insertion hole but does not pass out of the second ceramic sleeve.

[0023] As a further improved technical scheme of the utility model, each layer of heating belt comprises a first extension part connected with one end of the wave part and a second extension part connected with the other end of the wave part.

[0024] The electric heater further comprises:

[0025] A first connecting block is provided with a plurality of first installation grooves, and the first extension part is at least partially accommodated in the first installation grooves.

[0026] A second connecting block is provided with a plurality of second installation grooves, and the second extension part is at least partially accommodated in the second installation grooves.

[0027] The first electrode assembly comprises a first electrode connected with the first connecting block.

[0028] The second electrode assembly comprises a second electrode connected with the second connecting 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 scheme of the utility model, each first extension part is in a straight strip shape; and / or

[0031] Each second extension part is in a straight strip shape.

[0032] As a further improved technical scheme of the utility model, each first extension part is in a straight strip shape, and the first extension parts of the plurality of layers of heating belts are parallel to each other; and the first installation grooves of the first connecting block are parallel to each other.

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

[0034] The first extension parts of the plurality of layers of heating belts are arranged at equal intervals; and the first installation grooves of the first connecting block are arranged at equal intervals.

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

[0036] The utility model further discloses a tail gas aftertreatment device which comprises:

[0037] An air inlet assembly;

[0038] an electric heater located downstream of the air intake assembly in the airflow direction;

[0039] a first exhaust gas aftertreatment module located downstream of the electric heater in the airflow direction;

[0040] a second exhaust gas aftertreatment module located downstream of the first exhaust gas aftertreatment module in the airflow direction;

[0041] a mixer assembly located downstream of the second exhaust gas aftertreatment module in the airflow direction;

[0042] a third exhaust gas aftertreatment module located downstream of the mixer assembly in the airflow direction; and

[0043] an air outlet assembly located downstream of the third exhaust gas aftertreatment module in the airflow direction;

[0044] wherein the electric heater is the aforementioned electric heater.

[0045] Compared with the prior art, the electric heater of the utility model includes a heating band assembly, a support frame and a plurality of pin assemblies, the pin assemblies fix the heating band to the support frame in the axial direction of the electric heater; the pin assemblies include a first ceramic sleeve, a second ceramic sleeve and a pin; the first ceramic sleeve is inserted through the mounting perforation, the second ceramic sleeve is at least partially sleeved on the first ceramic sleeve, the second ceramic sleeve is located between the heating band and the support frame in 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 with the heating band. In this way, the second ceramic sleeve of the utility model can limit the distance between the heating band and the support frame; the pin assemblies realize the insulation with the support frame while fixing the heating band. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a principle schematic view of the exhaust gas aftertreatment device of the utility model.

[0047] Figure 2 is a three-dimensional schematic view of the electric heater of the utility model in an embodiment.

[0048] Figure 3 is Figure 2 a three-dimensional schematic view from another angle.

[0049] Figure 4 is Figure 2 a front view.

[0050] Figure 5 is Figure 3 a front view.

[0051] Figure 6 is Figure 4 a close-up view of the frame portion A.

[0052] Figure 7 is Figure 4 a close-up view of the frame portion B.

[0053] Figure 8 is Figure 2 a left side view of the

[0054] Figure 9 is a cross-sectional view along the line C-C of the Figure 8

[0055] is Figure 10 a partial exploded view of the Figure 2 where the first electrode assembly and the second electrode assembly are separated.

[0056] Figure 11 is Figure 10 a partial exploded view of the

[0057] Figure 12 is Figure 10 a partial exploded view of the

[0058] Figure 13 is Figure 12 a partial exploded view of the

[0059] Figure 14 is Figure 12 a further exploded view of the

[0060] Figure 15 is a perspective view of the pin assembly.

[0061] Figure 16 is Figure 15 a perspective exploded view of the

[0062] Figure 17 is Figure 15 a perspective view of the

[0063] Figure 18 is Figure 17 a perspective exploded view of the

[0064] Figure 19 is a perspective exploded view of the first connection block, the second connection block, the heating tape assembly, the first electrode assembly, and the second electrode assembly.

[0065] Figure 20 is a front view of the first connection block, the second connection block, the heating tape assembly, the first electrode assembly, and the second electrode assembly.

[0066] Figure 21 is a rear view of Figure 20 .

[0067] Figure 22 is a partial enlarged view of the circled portion D in Figure 20 .

[0068] Figure 23 is a partial enlarged view of the circled portion E in Figure 20 .

[0069] Figure 24 is a cross-sectional view along the line F-F in Figure 4 . DETAILED DESCRIPTION

[0070] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings, in which several specific embodiments are present, and the features in these embodiments can be combined with each other if there is no conflict. When the description refers to the drawings, the same numbers or symbols in different drawings represent the same or similar elements unless otherwise specified. The description in the following exemplary embodiments does not represent all embodiments of the present application, but rather, they are merely examples of the products consistent with the present application as recited in the claims of the present application.

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

[0072] Please refer to Figure 1As shown, the utility model discloses a kind of tail gas aftertreatment devices, it includes air intake component 200, downstream of the air intake component 200 along airflow direction electric heater 100, downstream of the electric heater 200 along the airflow direction first tail gas aftertreatment module 300 (for example, diesel oxidation catalyst, DOC), downstream of the first tail gas aftertreatment module 300 along the airflow direction second tail gas aftertreatment module 400 (for example, diesel particulate filter, DPF), downstream of the second tail gas aftertreatment module 400 along the airflow direction mixer component 500, urea nozzle 600 installed on the mixer component 500, downstream of the mixer component 500 along the airflow direction third tail gas aftertreatment module 700 (for example, selective catalytic reduction, SCR), and downstream of the third tail gas aftertreatment module 700 along the airflow direction air outlet component 800.The first tail gas aftertreatment module 300, the second tail gas aftertreatment module 400 and the third tail gas aftertreatment module 700 are collectively referred to as tail gas aftertreatment module. Please refer to Figure 1 As shown, the airflow direction is Figure 1 The direction indicated by hollow arrow.

[0073] Please combine Figures 2 to 24 As shown, the utility model discloses the embodiment of the drawing reveals a kind of electric heater 100, for the tail gas aftertreatment device in, the electric heater 100 includes shell 1, heating band component 2 at least partially in the shell 1, first electrode component 3 installed on the shell 1, second electrode component 4 installed on the shell 1, first connecting block 5 connecting one end of the heating band component 2 with the first electrode component 3, second connecting block 6 connecting the other end of the heating band component 2 with the second electrode component 4, support frame 7 at least partially in the shell 1, and several pin assemblies 8 along the axial direction of the electric heater 100, the heating band component 2 is fixed to the support frame 7.

[0074] In the embodiment shown in the utility model, the shell 1 is made of metal material, for example, made of stainless steel material. The shell 1 is generally hollow cylindrical, and the shell 1 is provided with a mounting space 10. The shell 1 comprises an outer surface 11 and an inner surface 12 opposite to the outer surface 11, and the inner surface 12 is exposed to the mounting space 10. The shell 1 further comprises a first mounting hole 13 penetrating through the outer surface 11 and the inner surface 12 and communicating with the mounting space 10, and a second mounting hole 14 penetrating through the outer surface 11 and the inner surface 12 and communicating with the mounting space 10. In the embodiment shown in the utility model, the first mounting hole 13 and the second mounting hole 14 are both circular perforations. Of course, those skilled in the art can understand that in other embodiments of the utility model, the first mounting hole 13 and the second mounting hole 14 can also be other shapes, including but not limited to oval holes, waist-shaped holes, rectangular holes, trapezoidal holes, triangular holes and the like, and the utility model will not be described here. In addition, in the embodiment shown in the utility model, the outer surface 11 and the inner surface 12 are both arc surfaces. Of course, those skilled in the art can understand that in other embodiments of the utility model, the outer surface 11 and the inner surface 12 can also be flat surfaces.

[0075] In the embodiment shown in the utility model, the heating band assembly 2 comprises a plurality of layers of heating bands 21 made of metal material. In the embodiment shown in the utility model, the heating band assembly 2 comprises seven layers of heating bands 21, wherein each layer of heating band 21 comprises a wave part 210, a first extension part 211 connected to one end of the wave part 210, and a second extension part 212 connected to the other end of the wave part 210. The wave part 210 is generally wavy, and is provided with wave crests and wave troughs. Adjacent two layers of heating bands 21 are fixed together. In one embodiment of the utility model, the adjacent two layers of heating bands 21 are fixed together by brazing. Those skilled in the art can understand that the way of fixing the adjacent two layers of heating bands 21 together can be various, for example, the wave crest of one heating band 21 is fixed with the wave crest of the adjacent heating band 21; or the wave crest of one heating band 21 is fixed with the wave trough of the adjacent heating band 21; or the wave trough of one heating band 21 is fixed with the wave trough of the adjacent heating band 21. The heating band assembly 2 comprises a plurality of gap holes 22 between adjacent two layers of heating bands 21. Most of the plurality of gap holes 22 are used to flow through the tail gas, so as to heat the tail gas by the heating band assembly 2.

[0076] It is understood by those skilled in the art that the wave peaks of the heating strips 21 of each layer can be the same or different, and the wave troughs of the heating strips 21 of each layer can also be the same or different. The wave peaks of the heating strips 21 of adjacent two layers can be the same or different, and the wave troughs of the heating strips 21 of adjacent two layers can also be the same or different.

[0077] In the embodiment illustrated in the utility model, the plurality of layers of heating strips 21 are stacked and wound to form a disc shape. The heating strip assembly 2 comprises a plurality of layers from the inside to the outside in the radial direction, and a gap 23 is arranged between the inner layer of the heating strip assembly 2 and the outer layer of the heating strip assembly 2. The gap 23 is used to flow the tail gas, so as to heat the tail gas by the heating strip assembly 2.

[0078] In the embodiment illustrated in the utility model, preferably, the lengths of the heating strips 21 of each layer are the same, so as to evenly distribute the current to each heating strip 21 as much as possible. In the embodiment illustrated in the utility model, the first extension part 211 and the second extension part 212 are substantially in the shape of a straight strip. It is understood by those skilled in the art that the technology used in the utility model belongs to the "straight strip" and is not required to be completely flat and completely straight, and appropriate bending is also possible. In an embodiment of the utility model, the first extension part 211 and the second extension part 212 can even be arranged to be inclined with respect to the wave part 210. In the embodiment illustrated in the utility model, the plurality of layers of heating strips 21 comprise a first end 24 composed of the plurality of first extension parts 211 and a second end 25 composed of the plurality of second extension parts 212. In the embodiment illustrated in the utility model, the plurality of first extension parts 211 of the first end 24 are parallel to each other, and the plurality of second extension parts 212 of the second end 25 are also parallel to each other.

[0079] Preferably, in an embodiment of the utility model, the distance between any two adjacent first extension parts 211 in the plurality of first extension parts 211 is equal, in other words, the plurality of first extension parts 211 are arranged at equal intervals. Compared with the design that the plurality of first extension parts 211 are stacked and pressed together, this arrangement is not easy to cause heat concentration after being electrified, thereby reducing the risk of excessively high local temperature.

[0080] Similarly, in an embodiment of the utility model, the distance between any two adjacent second extension parts 212 in the plurality of second extension parts 212 is equal, in other words, the plurality of second extension parts 212 are arranged at equal intervals. Compared with the design that the plurality of second extension parts 212 are stacked and pressed together, this arrangement is not easy to cause heat concentration after being electrified, thereby reducing the risk of excessively high local temperature.

[0081] The first connecting block 5 is made of metal material, which comprises a first mounting part 51, a first connecting part 52 connected with the first mounting part 51, and a first accommodation space 53 located at the inner side of the first mounting part 51. The first mounting part 51 comprises a first surface 511 (for example, an upper surface), a second surface 512 (for example, a lower surface) opposite to the first surface 511, and a first fixing hole 513 penetrating through the first surface 511 and the second surface 512 and communicating with the first accommodation space 53. In an embodiment of the utility model, 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 shown in the utility model, the size of the first mounting hole 13 is greater than the size of the first fixing hole 513, so that the first electrode assembly 3 is facilitated to pass through the first mounting hole 13 during assembly.

[0082] The first connecting part 52 comprises 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 through the first end surface 523. In the embodiment shown in the utility model, the first mounting grooves 524 penetrate through 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 part 211. In order to improve the flexibility of installation, the length of the first mounting groove 524 is greater than the length of the first extension part 211. By accommodating the first extension part 211 in the first mounting groove 524, the contact area of the first extension part 211 and the first connecting block 5 is increased, and the connection stability of the two is improved.

[0083] Similarly, the second connecting block 6 is made of metal material, which comprises a second mounting part 61, a second connecting part 62 connected with the second mounting part 61, and a second accommodation space 63 located at the inner side of the second mounting part 61. The second mounting part 61 comprises a third surface 611 (for example, an outer surface), a fourth surface 612 (for example, an inner surface) opposite to the third surface 611, and a second fixing hole 613 penetrating through the third surface 611 and the fourth surface 612 and communicating with the second accommodation space 63. In an embodiment of the utility model, 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 shown in the utility model, the size of the second mounting hole 14 is greater than the size of the second fixing hole 613, so that the second electrode assembly 4 is facilitated to pass through the second mounting hole 14 during assembly.

[0084] The second connecting part 62 comprises 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 through the second end surface 623. In the embodiment shown in the drawings, the second mounting grooves 624 penetrate through 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 part 212. In order to improve the flexibility of installation, the length of the second mounting grooves 624 is greater than the length of the second extension part 212. By accommodating the second extension part 212 in the second mounting grooves 624, the contact area between the second extension part 212 and the second connecting block 6 is increased, and the connection stability of the two is improved.

[0085] The first electrode assembly 3 comprises a first electrode 31, a first insulation part 32 arranged on the first electrode 31, and a first shielding part 33 fixed with the first insulation part 32. In an embodiment of the present application, the first electrode 31 comprises a first main body part 311, a first transition part 312 connected with one end of the first main body part 311, a first fixed part 313 connected with the other end of the first main body part 311, and a first external thread part 314 connected with the first transition part 312. In the embodiment shown in the drawings, the first external thread part 314, the first transition part 312, the first main body part 311, and the first fixed part 313 are connected in sequence. In the embodiment shown in the drawings, the outer diameter of the first main body part 311 is greater than the outer diameter of the first external thread part 314. The first transition part 312 is in the shape of a circular truncated cone, comprising a large-diameter end connected with the first main body part 311 and a small-diameter end connected with the first external thread part 314, so that the first main body part 311, the first transition part 312, and the first external thread part 314 gradually change. The outer diameter of the first fixed part 313 is smaller than the outer diameter of the first main body part 311.

[0086] In the embodiment shown in the drawings, the first insulation part 32 is a ceramic sleeve, which is sleeved on 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 insulation part 32 is fixed in the first through hole 330 in an interference fit manner.

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

[0088] In the illustrated embodiment of the utility model, the first shielding part 33 is welded and fixed with the outer surface 11 of the shell 1, and the first shielding part 33 shields the first mounting hole 13. In addition, in order to avoid the heat generated during welding from damaging the first electrode 31 and / or the first insulation part 32, the first shielding part 33 is further provided with a first allowance hole 331 to reduce heat transfer as soon as possible through air. In the illustrated embodiment of the utility model, the first allowance hole 331 is generally conical, and the hole diameter of the end close to the heating band assembly 2 is greater than the hole diameter of the end away from the heating band assembly 2.

[0089] In the illustrated embodiment of the utility model, the first shielding part 33 is provided with a first force applying part 332, which is a hexagonal nut including six outer sides.

[0090] In the illustrated embodiment of the utility model, the first electrode 31, the first insulation part 32 and the first shielding part 33 are assembled into a first electrode assembly 3. Then, the first electrode assembly 3 is passed through the first mounting hole 13. In the illustrated embodiment of the utility model, the hole diameter of the first mounting hole 13 is greater 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 be more easily passed through the first mounting hole 13. This design is beneficial to improve the flexibility of installation and improve the convenience of installation. The first fixed part 313 is passed through the first mounting hole 13 and fixed in the first fixed hole 513. In an embodiment of the utility model, the first fixed part 313 is provided with external threads (not shown), and the external threads of the first fixed part 313 cooperate with the internal threads of the first fixed hole 513. The external threads of the first fixed part 313 can be tightened with the internal threads of the first fixed hole 513 by means of the hexagonal nut and the cooperating 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 allowance hole 331, and at least partially extends into the installation space 10.

[0091] Of course, those skilled in the art can understand that the first shielding part 33 can also not be provided with a first force applying part 332. At this time, when the first electrode assembly 3 is installed on the first connecting block 5, the external threads of the first fixed part 313 and the internal threads of the first fixed hole 513 can be tightened by means of the first external thread part 314 and through the installation tool.

[0092] In the embodiment shown in the utility model, the first fixed part 313 protrudes from the second surface 512 to facilitate observation of the installation condition. The first fixed part 313 partially protrudes into the first space 53, but the end of the first fixed part 313 and the heating band assembly 2 opposite thereto still maintain a proper safety distance, avoiding direct contact between the end of the first fixed part 313 and the heating band assembly 2 opposite thereto. Those skilled in the art can understand that the utility model is advantageous in reducing the risk of direct contact between the end of the first fixed part 313 and the heating band assembly 2 opposite thereto by arranging the first space 53.

[0093] Compared with the related art, the utility model realizes the connection and fixation of the first electrode 31 and the first connecting block 5 in a mechanical connection mode, avoiding damage to the first electrode 31 caused by high temperature during welding connection.

[0094] Similarly, the second electrode assembly 4 comprises a second electrode 41, a second insulation part 42 arranged on the second electrode 41 and a second shielding part 43 fixed with the second insulation part 42. In an embodiment of the utility model, the second electrode 41 comprises a second main body part 411, a second transition part 412 connected with one end of the second main body part 411, a second fixed part 413 connected with the other end of the second main body part 411 and a second external thread part 414 connected with the second transition part 412. In the embodiment shown in the utility model, the second external thread part 414, the second transition part 412, the second main body part 411 and the second fixed part 413 are sequentially connected. In the embodiment shown in the utility model, the outer diameter of the second main body part 411 is greater than the outer diameter of the second external thread part 414. The second transition part 412 is in the shape of a circular truncated cone, comprising a large-diameter end connected with the second main body part 411 and a small-diameter end connected with the second external thread part 414, so that the second main body part 411, the second transition part 412 and the second external thread part 414 gradually change. The outer diameter of the second fixed part 413 is smaller than the outer diameter of the second main body part 411.

[0095] In the embodiment shown in the utility model, the second insulation part 42 is a ceramic sleeve, which is sleeved on 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 perforation 430, and the second insulation part 42 is fixed in the second perforation 430 in an interference fit manner.

[0096] Of course, those skilled in the art can understand that the second insulation part 42 is also an insulating coating (for example, a ceramic coating) plated on the second body part 411, which can also play an insulating role, and the present application will not be described here.

[0097] In the illustrated embodiment of the present application, the second shielding part 43 is welded to the outer surface 11 of the shell 1, and the second shielding part 43 shields the second mounting hole 14. In addition, in order to avoid the heat generated during welding from damaging the second electrode 41 and / or the second insulation part 42, the second shielding part 43 is further provided with a second accommodation hole 431 to quickly reduce heat transfer through air. In the illustrated embodiment of the present application, the second accommodation hole 431 is generally conical, and the hole diameter near one end of the heating ribbon assembly 2 is greater than the hole diameter away from the one end of the heating ribbon assembly 2.

[0098] In the illustrated embodiment of the present application, the second shielding part 43 is provided with a second force applying part 432, which is a hexagonal nut including six outer sides.

[0099] In the illustrated embodiment of the present application, the second electrode 41, the second insulation part 42, and the second shielding part 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 application, the hole diameter of the second mounting hole 14 is greater 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 be more easily passed through the second mounting hole 14. This design is beneficial to improve the flexibility of installation and improve the convenience of installation. The second fixing part 413 is passed through the second mounting hole 14 and fixed in the second fixing hole 613. In an embodiment of the present application, the second fixing part 413 is provided with external threads (not shown), and the external threads of the second fixing part 413 cooperate with the internal threads of the second fixing hole 613. The external threads of the second fixing part 413 can be tightened with the internal threads of the second fixing hole 613 by means of the hexagonal nut and the installation tool cooperating therewith. 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 accommodation hole 431, and at least partially extends into the mounting space 10.

[0100] Of course, those skilled in the art can understand that the second shielding part 43 can also not be provided with the second force applying part 432. At this time, when the second electrode assembly 4 is installed on the second connecting block 6, the second outer threaded part 414 can be used to tighten the outer thread of the second fixing part 413 with the inner thread of the second fixing hole 613 through an installation tool.

[0101] In the embodiment shown in the utility model, the second fixing part 413 protrudes from the fourth surface 612 to facilitate observation of the installation condition. The second fixing part 413 partially protrudes into the second space 63, but the end of the second fixing part 413 and the heating belt assembly 2 opposite to it still maintain a proper safety distance to avoid direct contact between the end of the second fixing part 413 and the heating belt assembly 2 opposite to it. Those skilled in the art can understand that the utility model is advantageous in reducing the risk of direct contact between the end of the second fixing part 413 and the heating belt assembly 2 opposite to it by providing the second space 63.

[0102] Compared with the related art, the utility model realizes the connection and fixation of the second electrode 41 and the second connecting block 6 in a mechanical connection mode, avoiding damage to the second electrode 41 caused by high temperature generated during welding connection.

[0103] Those skilled in the art can understand that one of the first electrode 31 and the second electrode 41 of the utility model is a positive electrode, and the other is a negative electrode. Preferably, the first electrode assembly 3 and the second electrode assembly 4 are structurally identical to be able to share parts and save costs. Preferably, the first connecting block 5 and the second connecting block 6 are structurally identical to be able to share parts and save costs.

[0104] The support frame 7 is made of a metal material. The support frame 7 includes an inner edge part 71, an outer edge part 72, and a plurality of spokes 73 connecting the inner edge part 71 and the outer edge part 72. The outer edge part 72 is located on a circular contour line. The outer edge part 72 is provided with a first notch 721 corresponding to the first electrode assembly 3 and a second notch 722 corresponding to the second electrode assembly 4. The first notch 721 and the second notch 722 can allow exhaust gas to flow through, reducing the shielding of the first electrode assembly 3 and the second electrode assembly 4, thereby being advantageous in reducing the risk of overheating of the first electrode 31 and the second electrode 41. The inner edge part 71 is in the form of a peripheral surrounding frame to increase the structural strength.

[0105] Those skilled in the art can understand that, in general, in order to improve the structural strength, the outer edge part 72 is designed as an integral outer frame structure. However, such a design will cause 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 first gap 721 and the second gap 722 are designed innovatively in the utility model, which solves the risk of overheating of the first electrode 31 and the second electrode 41 due to being blocked by the outer edge part 72.

[0106] In the embodiment shown in the utility model, the outer edge part 72 is welded and fixed to the inner surface 12 of the shell 1 to be fixed with the shell 1.

[0107] The inner edge part 71 and the outer edge part 72 are connected through the spokes 73, which can play a role in strengthening the structural strength. In the embodiment shown in the utility model, each spoke 73 is provided with a plurality of mounting perforations 731. Preferably, the mounting perforations 731 are round holes. Of course, those skilled in the art can understand that the mounting perforations 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 an embodiment of the utility model, the pin 81 is made of metal material. The pin 81 includes an abutting part 811 and a pin part 812 connected with the abutting part 81. The first ceramic sleeve 82 includes a first base part 821 and a first cylindrical part 822 connected with the first base part 821. The first base part 821 is provided with a first insertion hole 8211, and the first cylindrical part 822 is provided with a passage 8221 in communication with the first insertion hole 8211. The second ceramic sleeve 83 includes a second insertion hole 831.

[0109] During assembly, the first ceramic sleeve 82 is first inserted and passed through the mounting perforation 731; then the second ceramic sleeve 83 is at least partially sleeved on 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 is passed through the first ceramic sleeve 82 and the second ceramic sleeve 83 and inserted into the gap hole 22; finally, the pin 81 is fixed with the heating band 21.

[0110] Specifically, the first cylindrical part 822 is inserted into and passes through the installation perforation 731, and the first base 821 abuts one side of the support frame 7. The first cylindrical part 822 is inserted into the second insertion hole 831 of the second ceramic sleeve 83, and the second ceramic sleeve 83 abuts the other side of the support frame 7. In the embodiment shown in the utility model, the first cylindrical part 822 is inserted into the second insertion hole 831 but does not pass out of the second ceramic sleeve 83. The insertion pin part 812 is inserted into and passes through the first insertion hole 8211 and the passage 8221, the insertion pin part 812 is fixed with the heating band 21, and the abutting part 811 abuts the first base 821.

[0111] The insertion pin part 812 is welded and fixed with the heating band 21. In an embodiment of the utility model, the insertion pin part 812 is brazed and fixed with the heating band 21.

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

[0113] The electric heater 100 of the utility model comprises a first connecting block 5, the first connecting block 5 is equipped with a first fixed hole 513, the first electrode assembly 3 comprises a first electrode 31, the first electrode 31 is equipped with a first fixed part 313, and the first fixed part 313 is connected with the first fixed hole 513 by the threaded cooperation mode, so that the structural reliability problem possibly caused by the direct welding of the first electrode 31 and the heating band assembly 2 is avoided, and the durability is improved.

[0114] Similarly, the electric heater 100 of the utility model comprises a second connecting block 6, the second connecting block 6 is equipped with a second fixed hole 613, the second electrode assembly 4 comprises a second electrode 41, the second electrode 41 is equipped with a second fixed part 413, and the second fixed part 413 is connected with the second fixed hole 613 by the threaded cooperation mode, so that the structural reliability problem possibly caused by the direct welding of the second electrode 41 and the heating band assembly 2 is avoided, and the durability is improved.

[0115] In addition, the utility model discloses a first connecting block 5 and second connecting block 6 with the above structure are arranged, the first mounting slot 524 on the first connecting block 5 is used to contain the first extension 211, and the second mounting slot 624 on the second connecting block 6 is used to contain the second extension 212, which is favorable to the current relatively evenly distributed to each layer heating band 21 through the first connecting block 5 and the second connecting block 6, thereby facilitating 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 utility model 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 assemblies 8 include a first ceramic sleeve 82, a second ceramic sleeve 83 and a pin 81, the first ceramic sleeve 82 is inserted through the mounting perforation 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 is inserted into the gap hole 22 through the first ceramic sleeve 82 and the second ceramic sleeve 83, and the pin 81 is fixed with the heating band 21. In this way, the second ceramic sleeve 83 of the utility model can limit the distance between the heating band 21 and the support frame 7, and the pin assemblies 8 can realize insulation with the support frame 7 while fixing the heating band 21.

[0117] The above embodiments are only used to illustrate the utility model and not to limit the technical solutions described in the utility model, and the understanding of the specification should be based on the technical personnel in the art, although the utility model has been described in detail with reference to the above embodiments, but the ordinary skilled in the art should understand that the technical personnel in the art can still modify or equivalently replace the utility model, and all technical solutions and improvements that do not deviate from the spirit and scope of the utility model should be covered in the scope of claims of the utility model.

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 described in claim 2, 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) further 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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