Exhaust gas heater

Abstract

The invention relates to an exhaust gas heater for an exhaust gas system of an internal combustion engine, having a carrier arrangement (30) through which exhaust gas can flow essentially in the direction of the longitudinal axis (L) of the exhaust gas heater and at least one heating conductor (18, 20) supported on the carrier arrangement (30), characterized in that the at least one heating conductor (18, 20) is constructed from a flat material which is curved in order to provide an at least locally corrugated heating conductor profile, with heating conductor flat sides which are opposite one another and heating conductor wide sides which are opposite one another.

Description

Technical Field

[0001] The present invention relates to an exhaust heater for an exhaust device for an internal combustion engine, the exhaust heater having a support arrangement structure in which exhaust gas flows substantially along the longitudinal axis of the exhaust heater and at least one heating conductor supported on the support arrangement structure. Background Technology

[0002] Such exhaust heaters are typically used to heat the exhaust gas or other gas guided through the exhaust system of an internal combustion engine, so as to transfer the heat transferred to the exhaust gas or gas in the area of ​​the exhaust system downstream of the exhaust heater to other system areas, such as exhaust treatment units, catalytic converters or particulate filters, so as to bring such system areas to operating temperature as quickly as possible, especially during the start-up phase of combustion operation or before the start of combustion operation of the internal combustion engine.

[0003] An exhaust heater is known from German patent application DE 10 2020 123 376, in which the heating conductor is composed of a plurality of corrugated regions. In each corrugated region, radially staggered corrugated segments extend substantially circumferentially. The heating conductor is provided as a material element by being separated from a flat metal material, thereby allowing for a high degree of freedom in shaping the heating conductor in each corrugated region or in the corrugated segments within each corrugated region. Summary of the Invention

[0004] The objective of this invention is to provide an exhaust heater for an exhaust system of an internal combustion engine, which enables improved heating efficiency.

[0005] According to the present invention, the task is solved by an exhaust heater for an exhaust device for an internal combustion engine, having a support arrangement structure through which exhaust gas can flow substantially along the longitudinal axis of the exhaust heater and at least one heating conductor supported on the support arrangement structure.

[0006] The at least one heating conductor is constructed of a flat material bent to provide at least a partially corrugated distribution of heating conductors, having flat sides of heating conductors facing each other and wide sides of heating conductors facing each other.

[0007] In the construction of the exhaust heater according to the invention, the heating conductor is not provided by separating it from a pre-defined, shaped, flat metal material, i.e., by punching or cutting it out, but rather by bending, for example, a strip of flat material into the shape set by the heating conductor. This makes it possible to provide a heating conductor with a structure that is very thin, particularly transverse to the exhaust flow direction, yet relatively wide along the exhaust flow direction, thereby reducing flow resistance in the exhaust heater on the one hand, and providing a relatively large surface area available for heat transfer on the other.

[0008] This can be achieved, in particular, in the case where the at least one heating conductor is arranged such that its wide side extends substantially along the longitudinal axis of the exhaust heater and its flat side extends substantially orthogonally to the longitudinal axis of the exhaust heater.

[0009] According to a particularly advantageous aspect of the invention, which is also independent of the manner in which the heating conductor is formed, the at least one heating conductor has at least one corrugated region comprising a plurality of corrugated segments extending longitudinally along the longitudinal direction of the corrugated segments and substantially parallel to each other. Corrugated segments that are directly adjacent to each other transversely to the longitudinal direction of the corrugated segments are interconnected in their respective end regions by corrugated segment connecting sections. This arrangement allows for a very tight assembly of the individual corrugated segments and thus a large surface area for heat transfer with respect to the total cross-section through which exhaust gas can pass.

[0010] Further increases in the surface available for heat transfer can be achieved by having at least one, preferably substantially each corrugated section, at least locally formed in a wavy manner between its end regions, having a plurality of successive crests along the longitudinal direction of the corrugated section.

[0011] Especially when the heating conductor is provided by a flat material bent into a desired shape, it is advantageous for manufacturing to be as simple as possible that the at least one heating conductor has at least two heating conductor corrugated regions, wherein a first heating conductor corrugated region of the at least two heating conductor corrugated regions provides a first connection area for connecting the at least one heating conductor to a power source and a second heating conductor corrugated region of the at least two heating conductor corrugated regions provides a second connection area for connecting the at least one heating conductor to a power source.

[0012] Here, at least one corrugated area of ​​the heating conductor can be provided by a single heating conductor material piece. This means that such a corrugated area of ​​the heating conductor can be provided without mechanically or electrically connecting different or separately constructed material pieces to each other. It is particularly advantageous here that all corrugated areas of the heating conductor are provided by a single heating conductor material piece, so that no connecting process for combining individual material pieces is required to provide the entire heating conductor.

[0013] Especially when the exhaust heater is large in size or the heating conductors are relatively complexly distributed, it can be advantageous for simple manufacturing that at least two heating conductor corrugated areas are provided by separate heating conductor material pieces.

[0014] When at least two, preferably all, heating conductor corrugated areas provided by separate heating conductor material pieces are substantially identical in shape to each other, the construction can be simplified by using the same components.

[0015] In order to achieve the most uniform flow through the exhaust heater in its entire cross-section during heating operation, it is proposed that at least two corrugated areas of the heating conductors, provided by each individual heating conductor material element, are substantially mirror-symmetrical about a plane of symmetry containing the longitudinal axis of the heating conductors.

[0016] When the heating conductor is constructed of two corrugated areas, each provided by a separate heating conductor material, these two corrugated areas can be arranged substantially mirror-symmetrically to each other about a plane of symmetry containing the longitudinal axis of the heating conductor. If the heating conductor is constructed, for example, of four corrugated areas provided by separate heating conductor material, these four corrugated areas can be arranged substantially mirror-symmetrically to each other in pairs about two mutually orthogonal planes containing the longitudinal axis of the heating conductor.

[0017] According to another aspect of the invention, which is independent but particularly advantageous in conjunction with the design aspects discussed earlier, the support arrangement structure may have a support housing including a housing bottom that extends substantially transversely to the longitudinal axis of the exhaust heater and is disposed on a first side of the axial direction of the at least one heating conductor, wherein a plurality of exhaust flow openings are provided in the housing bottom, and wherein the at least one heating conductor is supported on the housing bottom by a plurality of support elements.

[0018] In order to ensure the stability of the heating conductor in the support arrangement structure on the one hand, and to keep the resulting flow resistance as small as possible on the other hand, it is proposed that at least one, preferably each support element has a support pin fixed to the bottom of the housing and a support sleeve supported on the support pin and fixed to the at least one heating conductor, with an electrically insulating material, preferably magnesium oxide, provided in the middle, or / and at least one, preferably each support element is arranged with the longitudinal axis of the support element substantially parallel to the longitudinal axis of the exhaust heater.

[0019] For a design that is simple to implement, yet mechanically stable, and especially resistant to exhaust and temperature, the support housing and the support pins and sleeves of the at least one, preferably each, support element can be constructed of metallic material. The support pins of the at least one, preferably each, support element can be connected to the bottom of the housing by material locking, preferably by welding or brazing. Furthermore, the support sleeves of the at least one, preferably each, support element can be connected to the at least one heating conductor by material locking, preferably by welding or brazing.

[0020] In particular, when the heating conductor is constructed from multiple material components provided separately from each other, it is advantageous for a stable construction and for achieving conductive connection between all the material components that at least two heating conductor corrugated areas provided as separate heating conductor material components are conductively connected to each other by means of at least one support element that supports them on the support housing.

[0021] In order to connect, for example, the bracket housing to a tubular or shell-shaped exhaust guide member of the exhaust device, the bracket housing may have a circumferential wall that is radially externally connected to the bottom of the housing.

[0022] The support housing can be constructed in a can shape with a housing bottom and circumferential walls. In order to achieve the defined flow guidance on the one hand, and to keep the flow resistance as small as possible on the other hand, and despite this, to provide a large heat transfer surface, it is further proposed that the at least one heating conductor is substantially not covered by the support arrangement structure on the axial second side or / and the at least one heating conductor extends axially beyond the circumferential wall on the axial second side.

[0023] The present invention further relates to an exhaust system for an internal combustion engine, having at least one exhaust treatment unit, preferably a catalytic converter and / or a particulate filter, and at least one exhaust heater constructed according to the present invention upstream of the at least one exhaust treatment unit along the main exhaust flow direction. Attached Figure Description

[0024] The invention will now be described in detail with reference to the accompanying drawings.

[0025] Figure 1A perspective view of the exhaust heater is shown, for example, on a first side oriented in the upstream direction with respect to the main exhaust flow direction;

[0026] Figure 2 This is shown as viewed from, for example, the second side oriented in the downstream direction with respect to the main exhaust flow direction. Figure 1 A perspective view of the exhaust heater shown in the image;

[0027] Figure 3 Shown from the second side in the axial direction Figure 1 and 2 An axial view of the exhaust heater;

[0028] Figure 4 Show Figure 1 and 2 Detailed view of the exhaust heater;

[0029] Figure 5 Show Figure 1 and 2 Another detailed view of the exhaust heater;

[0030] Figure 6 This illustrates an alternative design form of the exhaust heater. Figure 2 The view;

[0031] Figure 7 Show Figure 6 The exhaust heater has a heating conductor consisting of two corrugated areas of heating conductors made of separate materials.

[0032] Figure 8 This illustrates an alternative design for a heating conductor, comprising four corrugated regions of the heating conductor provided as separate material components. Figure 7 The view;

[0033] Figure 9 This illustrates an alternative design for an exhaust heater. Figure 1 The view;

[0034] Figure 10 Show Figure 9 Side view of the exhaust heater;

[0035] Figure 11 A schematic diagram of an exhaust system for an internal combustion engine, including an exhaust heater and an exhaust treatment unit, is shown. Detailed Implementation

[0036] See next for reference. Figures 1 to 10 Before explaining the different design forms of exhaust heaters that can be used in the exhaust systems of internal combustion engines, refer to... Figure 11This section explains how such an exhaust heater can be integrated into the exhaust system of an internal combustion engine, for example, in a vehicle.

[0037] Figure 11 A schematic diagram of such an exhaust device 10 is shown, comprising an exhaust guide member 12, which may be tubular or shell-like and, if necessary, composed of multiple components. In the upstream region of the exhaust guide member 12, an exhaust heater, generally indicated by 14, is arranged such that exhaust gas flowing towards the exhaust heater 14 in the exhaust guide member 12 along the main exhaust flow direction A enters the exhaust heater 14 on a first axial side 16. The exhaust heater 14 is permeated by exhaust gas, which receives heat from two heating conductors 18, 20 arranged sequentially along the longitudinal axis L of the exhaust heater as it permeates the exhaust heater 14. After permeating the exhaust heater 14 or the heating conductors 18, 20 arranged sequentially along the main exhaust flow direction A or the longitudinal axis L of the exhaust heater, the heated exhaust gas flows out of the exhaust heater 14 on a second axial side 22 and flows into an exhaust treatment unit 24 arranged downstream of the exhaust heater 14. This exhaust treatment unit may be constructed, for example, as a catalyst and has a catalyst block 28 supported, for example, in the exhaust guide member 12 by means of a fibrous support material 26.

[0038] The exhaust gas heated in the exhaust heater 14 or another gas introduced into the exhaust guide member 12 and flowing through the exhaust heater 14 transfers heat to the exhaust treatment unit 24, thereby quickly placing the exhaust treatment unit, especially before or at the start of the internal combustion engine, at the temperature required to carry out the catalytic reaction, and significantly shortening the duration for which the exhaust gas is ejected with virtually no purification effect.

[0039] Next, refer to Figures 1 to 5 The first design of such an exhaust heater 14 is explained in detail.

[0040] The exhaust heater 14 has a support arrangement generally indicated by 30, on which, in the illustrated design example, the two heating conductors 18, 20, arranged sequentially along the longitudinal axis L of the exhaust heater, are supported in the support arrangement. The support arrangement 30 has a support housing 32, provided, for example, as a sheet metal forming element, comprising a housing bottom 34 arranged substantially transversely, i.e., substantially orthogonally, to the longitudinal axis L of the exhaust heater, and a circumferential wall 36 radially connected externally to the housing bottom 34. The support housing 32 thus has a substantially canister-like structure and its housing bottom 34 covers the two heating conductors 18, 20 substantially only on a first axial side 16. On a second axial side 22, the support housing 32 is, in principle, open and preferably not covered by the two heating conductors 18, 20 in any radial region.

[0041] To enable the exhaust gas circulation heating conductors 18 and 20, multiple substantially uniformly distributed exhaust gas flow openings 38 are formed in the bottom 34 of the housing. If the exhaust gas heater 14 is also... Figure 11 The exhaust is positioned in the exhaust device 10 or its exhaust guide member 12 such that the bottom 34 of the housing or the first axial side 16 is oriented upstream, and thus the exhaust flows along the main exhaust flow direction A toward the bottom 34 of the support housing 32. The exhaust enters the interior space of the support housing 32 in the region of the exhaust flow opening 38, in which the two heating conductors 18, 20 are positioned. The exhaust circulates substantially along the direction corresponding to the main exhaust flow direction A or the longitudinal axis L of the exhaust heater, and exits the support housing 32 on the essentially open axial second side 22 after thermal interaction with the heating conductors 18, 20.

[0042] It should be noted that, in principle, the exhaust heater 14 may also be integrated into the exhaust device 10 in another orientation, so that the exhaust flowing toward the exhaust heater along the main exhaust flow direction A enters the support housing 32 on the second axial side 22 and circulates the heating conductors 18, 20 in the region of the exhaust flow opening 38 before being discharged from the support housing 32 on the first axial side 16.

[0043] Next, the basic construction of the two heating conductors 18, 20 will be explained with reference to the heating conductor 20 positioned closer to the axial direction on the second side 22. The two heating conductors 18, 20 are substantially identical to each other, but not entirely constructed, so that they are not perfectly aligned when viewed along the longitudinal axis of the exhaust heater, thus allowing for improved thermal interaction with the exhaust gas or gas circulating through the heating conductors. However, the subsequent embodiments are also, in principle, applicable to the construction of the heating conductor 16 positioned closer to the axial direction on the first side 16.

[0044] Heating conductor 18 in exhaust heater 14 Figures 1 to 5The design example shown is manufactured using a single heating conductor material component 59. Specifically, the heating conductor 18 is constructed from a conductive, typically metallic, strip-shaped flat material, which is bent to achieve the desired shape of the heating conductor 20. The heating conductor 20 thus has wide sides 40, 42 facing each other, which extend substantially along or are oriented parallel to the longitudinal axis L of the exhaust heater. The heating conductor 20 also has flat sides 44, 46, which are oriented substantially orthogonally to the wide sides 40, 42 and also to the longitudinal axis L of the exhaust heater. Therefore, by designing the heating conductor 20, or each of the heating conductors 18, 20, as a flat material, it is possible, even when using a very thin flat material—that is, a flat material with relatively small extension or thickness on the flat sides 44, 46—to provide a large heat transfer surface area through the correspondingly large dimensions of the wide sides 40, 42. The extension dimension of the wide sides 40, 42 of the heating conductors along the longitudinal axis of the exhaust heater can, for example, be more than five times, preferably more than ten times, the extension dimension of the flat sides 44, 46 of the heating conductors orthogonal to the longitudinal axis L of the exhaust heater. Therefore, each heating conductor 18, 20 is significantly wider relative to its thickness.

[0045] The heating conductor 20 is bent into such a shape that it provides two... Figure 3 The view shows heating conductor corrugated regions F1 and F2 located to the left or right of a symmetrical plane E1 that includes or is parallel to the longitudinal axis L of the exhaust heater. In each heating conductor corrugated region F1 and F2, the heating conductor 20 is composed of corrugated sections 48 that extend longitudinally along the longitudinal direction M of the corrugated section and are arranged substantially parallel to each other. Corrugated sections 48 that are directly adjacent to each other transversely to the longitudinal direction M of the corrugated section are connected to each other in their respective end regions 50 and 52 of the corrugated section arranged along the longitudinal direction M of the corrugated section by means of corresponding corrugated section connecting sections 54 and 56. Therefore, a corrugated distribution of corrugated sections 48 that extend substantially longitudinally along the longitudinal direction M of the corrugated section and are successively transverse to the longitudinal direction M of the corrugated section is generated in each heating conductor corrugated region F1 and F2.

[0046] exist Figure 5 It is clearly visible that the corrugated segments 48, arranged side by side transversely to the longitudinal direction M of the corresponding corrugated segments, have a generally wavy distribution between their respective corrugated segment end regions 50 and 52, including successive wave crests 60 and 61 spaced apart transversely to the longitudinal direction of the corrugated segments. The wave crests 60 and 61 thus form an alternating sequence of wave crests and troughs in the corrugated segments 48 along the longitudinal direction M of the corrugated segments.

[0047] By superimposing the wavy structure of each corrugated section 48 with the substantially corrugated structure of the heating conductor 20 in the corrugated regions F1 and F2 of the heating conductor, a relatively large total length of the heating conductor 20 and thus a large overall surface area for heat transfer are achieved in a compact structural form. Nevertheless, the overall structure of the heating conductor 18 can be easily integrated with the cross-sectional geometry of the support housing 32 that receives the heating conductor, for example in… Figure 3 The essentially circular cross-sectional geometry is clearly visible and provides roughly the same surface area available for heat transfer in each cross-sectional region.

[0048] exist Figures 1 to 5 In the design example shown, heating conductor 20 and heating conductor 18 are constructed from a single strip of heating conductor material 59. This means that a process of assembling individual material pieces is not required to manufacture heating conductors 20 or 18. By bending them into a desired shape including two heating conductor corrugated regions F1, F2, a structure that is substantially mirror-symmetrical with respect to the plane of symmetry E1 is achieved, wherein... Figure 3 In the region visible below, the two heating conductor corrugated regions F1 and F2 are connected to each other in their respective lowermost corrugated sections 48 by corrugated section connecting sections 58. These corrugated section connecting sections are connected to the corrugated section end regions 50 of the two corrugated sections 48 of the two heating conductor corrugated regions F1 and F2, respectively, near the circumferential wall 36, and are also formed as part of the heating conductor material 59 used to construct the heating conductor 20.

[0049] exist Figure 3 In the region shown above, the heating conductor 20 provides a first connection region 63 in the region of the first heating conductor corrugated region F1, in which the heating conductor 20 is connected to or can be connected to a connecting element 62 that electrically insulates over the circumferential wall 36 and, if necessary, the exhaust guide member 12, and is connected to or can be connected to a power source through this connecting element. Similarly, the heating conductor 20 provides a second connection region 64 in its second heating conductor corrugated region F2, in which the heating conductor can be connected to a power source through a connecting element 66. In the illustrated example where the two heating conductors 18, 20 are arranged sequentially along the longitudinal axis L of the exhaust heater, the heating conductors are preferably electrically connected in parallel to each other and are conductively connected to the connecting element 62 through a corresponding first connection region 63 and conductively connected to the connecting element 66 through a corresponding second connection region 64.

[0050] To ensure the stable holding of the heating conductors 18 and 20 on the support housing 32, multiple pin-shaped or bolt-shaped support elements 68 are provided. Figure 3As can be seen, each of the two corrugated areas F1 and F2 of the heating conductor is provided with two rows of such support elements 68, wherein in each row, the support elements 68 that are directly adjacent to each other are arranged laterally and staggered from each other in the longitudinal direction of the corresponding row.

[0051] Each support element 68 has a support pin 70, which is inserted into an opening 72 in the bottom 34 of the housing and fixed to the bottom 34 of the housing, for example by fusion welding or brazing, i.e., by material locking in principle, such that the support pin 70 and the entire support element 68 extend from the bottom 34 of the housing with the support element longitudinal axis S substantially along the longitudinal axis L of the exhaust heater.

[0052] Each support pin 70 is surrounded by a support sleeve 74 that is substantially cylindrical. To achieve electrical insulation between the respective support pin 70 and the support sleeve 74 surrounding it, an electrically insulating material 76, such as a ceramic material, magnesium oxide, or the like, is disposed between them. This can be achieved, for example, by coating the outer peripheral area of ​​the support pin 70 with such an electrically insulating material before the respective support sleeve 74 is pushed or pressed against the configured support pin 70.

[0053] In order to ensure an electrical short circuit between the bracket sleeve 74 and the housing bottom 34 in each bracket element 68, the bracket pin 70 extends beyond the respective bracket sleeve 74 with its longitudinal section to be inserted into the opening 72, so that when the bracket pin 70 is inserted into the opening 72, the bracket sleeve 74 is positioned at a distance from the housing bottom 34.

[0054] Heating conductors 18 and 20 are connected to the support sleeve 74 of the support element 68 in regions of corrugated sections 48, which are generally corrugated in a wave-like structure. Here, for example, it can be configured such that, where the corrugated section 48 is connected to the support sleeve 74, the corresponding corrugated crest 60 extends slightly further (wider) along the longitudinal direction M of the corrugated section than the other corrugated crests, thereby achieving a profile in this region that matches the outer peripheral profile of the corresponding support sleeve 74. In the length region surrounding or abutting the corresponding support sleeve 74, the corresponding corrugated section 48 can be connected to the support sleeve 74 by material locking, i.e., for example, fusion welding or brazing.

[0055] Because the support sleeve 74 and the support pin 70 are preferably constructed of metal, there is a conductive connection between the heating conductors 18 and 20 where they contact the same support sleeve 74. In order to achieve uniform current and therefore uniform heating despite this, it is therefore advantageous to design the heating conductors 18 and 20 to be of the same length or with the same resistance between all successive support sleeves 74 along the current direction that produce such short circuits.

[0056] exist Figures 3 to 5 It is evident that, for example, the connection of directly adjacent corrugated sections 48 in the respective heating conductor corrugated regions F1, F2 can be such that only every second corrugated section 48 is connected to the support element 68 or the support sleeve 74, while the corrugated section 48 in between has a wavy structure where a row of support elements 68 is formed in each of the two heating conductor corrugated regions F1, F2, and is interrupted by longitudinal sections 77 extending substantially straight along the longitudinal direction M of the corrugated section, so as to provide sufficient structural space for positioning the respective support element 68 without the risk of electrical short circuit.

[0057] In order to Figures 1 to 5 In the configuration shown, short circuits between the two heating conductors 18, 20 are avoided in principle where they should not occur. These heating conductors can be positioned with a small distance between them along the longitudinal axis L of the exhaust heater. To achieve this, for example, the support sleeve 14 can have a radially outwardly projecting distance-retaining region to create such a gap, and the two heating conductors 18, 20 can be axially aligned with said distance-retaining region where they contact the corresponding spacer sleeve 74.

[0058] An alternative design of the exhaust heater 14 is as follows: Figure 6 and 7 As shown in the diagram. In principle, only one heating conductor 18 is used in this exhaust heater 14, which, along the longitudinal axis L of the exhaust heater, can be constructed to be longer than each heating conductor 18, 20 in the previously described design example. Figure 6 and 7 The heating conductor 18, which is used and similarly constructed as two heating conductor corrugated regions F1 and F2 that are substantially mirror-symmetrical with respect to the plane of symmetry E1, is constructed of two separate heating conductor material parts 78 and 80. (As in...) Figure 7As can be seen, the basic distribution of the heating conductor 18 in the two corrugated regions F1 and F2 is constructed in the same manner as in the previously described design example. That is, here the corrugated sections 48 also extend longitudinally along the corresponding longitudinal direction M and are constructed in a wavy structure. The corrugated sections 48 that are directly adjacent to each other are interconnected in their end regions 50 and 52 by corrugated section connecting sections 54 and 56. Figure 7 It is evident that the two heating conductor material parts 78 and 80, which provide the corresponding heating conductor corrugated regions F1 and F2, are formed identically in principle, thereby again achieving the previously described substantially mirror-symmetric structure about the plane of symmetry E1. This means that the same components can be used for the two heating conductor corrugated regions F1 and F2, which simplifies the construction and reduces costs.

[0059] In each of the said heating conductor corrugated regions F1, F2, a connection region 63 or 64 is provided. In the respective end regions of the heating conductor material pieces 78, 70 or corrugated regions F1, F2, remote from the connection region 63 or 64, a corresponding final and, for example, substantially non-corrugated corrugated section 48 may provide connection regions 82, 83. These connection regions 82, 83 can be connected to the corrugated region connection section 58, now provided as a separate component, to electrically connect the two, in principle, separately constructed heating conductor corrugated regions F1, F2 to each other. Figure 6 As can be seen, the support element 68 can also be configured for the corrugated area connection section 58, so that in or near the connection areas 82, 83, the two heating conductor corrugated areas F1, F2 are supported on the support housing 32 by the component that electrically connects them, namely the corrugated area connection section 58 and the support element 68 connected to the corrugated area connection section in the manner and method described above.

[0060] Another design type of exhaust heater or heating conductor 18 used therein Figure 8 As shown in the diagram. It should be noted that, of course, this design also includes... Figure 6 and 7 In the design shown, the support housing 32 can, in principle, have the following characteristics: Figures 1 to 5 The structure already described.

[0061] exist Figure 8The heating conductor 18 shown is constructed with a total of four heating conductor corrugated regions F1, F2, F3, and F4. Each of these heating conductor corrugated regions F1, F2, F3, and F4 is constructed with a separate heating conductor material piece 78, 80, 84, or 86. Material pieces 78 and 80 used for constructing the first heating conductor corrugated region F1 and the second heating conductor corrugated region F2 provide connection regions 63 and 64. Material pieces 84 and 86 used for constructing the third heating conductor corrugated region F3 and the fourth heating conductor corrugated region F4 provide connection regions 82 and 83, through which the third heating conductor corrugated region F3 and the fourth heating conductor corrugated region F4 can be used, for example, in… Figure 6 The corrugated connecting sections 58, as can be seen in the diagram, are interconnected. These corrugated connecting sections can be supported on the support housing 32 by the support element 68.

[0062] Where the second heating conductor corrugated area F2 is adjacent to the third heating conductor corrugated area F3 or the first heating conductor corrugated area F1 is adjacent to the fourth heating conductor corrugated area F4, they can be mechanically and electrically connected to each other by the support element 68 shown in the schematic diagram and supported on the bottom 34 of the housing of the support housing 32.

[0063] Also there Figure 8 In the heating conductor 18 shown, heating conductor material pieces 78, 80, 84, and 86 with the same shape or bending can be used to construct the four heating conductor corrugated regions F1, F2, F3, and F4. This results in adjacent heating conductor corrugated regions being constructed or arranged in pairs with mirror symmetry about two planes of symmetry E1 and E2.

[0064] By using a total of four heating conductor material pieces 78, 80, 84, 86 or four heating conductor corrugated areas F1, F2, F3, F4 constructed therefrom, the length of each individual heating conductor material piece 78, 80, 84, 86 is significantly shorter, thereby making the manufacturing or bending process significantly simpler.

[0065] Figure 9 and 10 An alternative design for the support housing 32 used in the exhaust heater 14 is shown. Figure 9 As can be seen, different shaped exhaust flow openings 38 are provided in the bottom 34 of the housing. A portion of the exhaust flow opening 38 is formed with a circular cross-section, while another portion is formed in the shape of an elongated hole and extends, for example, in the direction in which the corresponding corrugated section 48 extends longitudinally along the longitudinal direction M of its corresponding corrugated section.

[0066] By shaping or varying the shape of the exhaust flow opening 38, it is possible to guide the exhaust in a defined manner and method to different areas of the interior space of the support housing 32, thereby achieving a defined inflow or circulation to the one or more heating conductors. It can also be seen that an axially protruding formed portion 88 can be provided on the bottom 34 of the housing for receiving the support pin 70, thereby achieving improved stability in that area.

[0067] exist Figure 10 As can be seen, although the bottom 34 of the support housing 32 is generally orthogonal or transverse to the longitudinal axis L of the exhaust heater, the bottom of the housing can be outward, that is, in principle, convex and arched. This improves the stability of the structure on the one hand, and ensures the defined flow guidance of the exhaust flowing towards the exhaust heater 14 along the main exhaust flow direction A.

[0068] Further in Figure 10 As can be seen, the one or more heating conductors 18, 20, and thereby the support element 68 supporting them, can be sized such that they extend beyond the circumferential wall 36 of the support housing 32 on the second axial side 22. Because the support housing 32 is, in principle, open on this second axial side, there is no conflict with the support housing 32, and the surface area of ​​the one or more heating conductors 18, 20 for heat transfer can be further increased.

[0069] It should be noted that, of course, the prior information regarding the support housing 32 or the heating conductors 18, 20 housed therein is... Figure 10 The structure described can be independent of the exhaust penetration opening 38. Figure 9 or Figure 1 The molding or arrangement structure shown is independent of whether a heating conductor is provided in the support housing 32 with a slightly further (wider) extension in the axial direction or two or more heating conductors arranged sequentially in the axial direction.

Claims

1. An exhaust heater for an exhaust system of an internal combustion engine, the exhaust heater having a support arrangement structure (30) through which exhaust gas can flow along the longitudinal axis (L) of the exhaust heater and at least one heating conductor (18, 20) supported on the support arrangement structure (30), wherein, - The at least one heating conductor (18, 20) is constructed of a flat material bent to provide at least a locally corrugated distribution of heating conductors, having flat sides (44, 46) of heating conductors facing each other and wide sides (40, 42) of heating conductors facing each other. - The at least one heating conductor (18, 20) has at least one heating conductor corrugated region (F1, F2, F3, F4), the heating conductor corrugated region comprising a plurality of parallel corrugated segments (48) extending longitudinally along the longitudinal direction (M) of the corrugated segments, wherein corrugated segments (48) that are directly adjacent to each other transversely to the longitudinal direction (M) of the corrugated segments are interconnected by corrugated segment connecting segments (54, 56) in their respective corrugated segment end regions (50, 52). - At least one corrugated section (48) has at least locally wavy ridges (60, 61) in the longitudinal direction (M) of the corrugated section between its end regions (50, 52). -The support arrangement structure (30) has a support housing (32) including a housing bottom (34) extending transversely to the longitudinal axis (L) of the exhaust heater, disposed on a first side (16) of the axial direction of the at least one heating conductor (18, 20), wherein a plurality of exhaust flow openings (38) are provided in the housing bottom (34). - The at least one heating conductor (18, 20) is supported on the bottom (34) of the housing by a plurality of support elements (68). - At least one support element (68) has a support pin (70) fixed on the bottom (34) of the housing and a support sleeve (74) supported on the support pin (70) with an electrical insulating material (76) in the middle and fixed to the at least one heating conductor (18, 20) by material locking in the region of the crest (60, 61).

2. The exhaust heater according to claim 1, characterized in that, The at least one heating conductor (18, 20) is arranged with its wide side (40, 42) extending along the longitudinal axis (L) of the exhaust heater and with its flat side (44, 46) extending orthogonally to the longitudinal axis (L) of the exhaust heater.

3. The exhaust heater according to claim 1 or 2, characterized in that, Each corrugated section (48) has at least locally wavy ridges (60, 61) in the longitudinal direction (M) of the corrugated section between its end regions (50, 52).

4. The exhaust heater according to claim 1 or 2, characterized in that, The at least one heating conductor (18, 20) has at least two heating conductor corrugated regions (F1, F2, F3, F4), wherein the first heating conductor corrugated region (F1) of the at least two heating conductor corrugated regions (F1, F2, F3, F4) provides a first connection area (63) for connecting the at least one heating conductor (18, 20) to a power source, and the second heating conductor corrugated region (F2) of the at least two heating conductor corrugated regions (F1, F2, F3, F4) provides a second connection area (64) for connecting the at least one heating conductor (18, 20) to a power source.

5. The exhaust heater according to claim 1 or 2, characterized in that, At least one heating conductor corrugated area (F1, F2, F3, F4) is provided by a single heating conductor material part (59, 78, 80, 84, 86).

6. The exhaust heater according to claim 5, characterized in that, All heating conductor corrugated areas (F1, F2) are provided by a single heating conductor material component (59).

7. The exhaust heater according to claim 1 or 2, characterized in that, At least two heating conductor corrugated areas (F1, F2, F3, F4) are provided by separate heating conductor material parts (78, 80, 84, 86).

8. The exhaust heater according to claim 7, characterized in that, At least two heating conductor corrugated regions (F1, F2, F3, F4) provided by each individual heating conductor material element (78, 80, 84, 86) are formed with the same shape as each other.

9. The exhaust heater according to claim 8, characterized in that, All the heating conductor corrugated areas (F1, F2, F3, F4) provided by each individual heating conductor material element (78, 80, 84, 86) are formed with the same shape as each other.

10. The exhaust heater according to claim 1 or 2, characterized in that, At least two corrugated heating conductor regions (F1, F2, F3, F4) provided by individual heating conductor material pieces (78, 80, 84, 86) are arranged in a mirror-symmetric manner about a plane of symmetry (E1, E2) containing the longitudinal axis (L) of the exhaust heater.

11. The exhaust heater according to claim 10, characterized in that, The heating conductor (18) is composed of two heating conductor corrugated areas (F1, F2) provided by separate heating conductor material parts (78, 80) and the two heating conductor corrugated areas (F1, F2) are arranged in mirror symmetry about a plane of symmetry (E1) containing the longitudinal axis (L) of the exhaust heater, or the heating conductor (18) is composed of four heating conductor corrugated areas (F1, F2, F3, F4) provided by separate heating conductor material parts (78, 80, 84, 86) and the four heating conductor corrugated areas (F1, F2, F3, F4) are arranged in pairs in mirror symmetry about two planes of symmetry (E1, E2) containing the longitudinal axis (L) of the exhaust heater and orthogonal to each other.

12. The exhaust heater according to claim 1 or 2, characterized in that, Each support element (68) has a support pin (70) fixed to the bottom (34) of the housing and a support sleeve (74) supported on the support pin (70) and fixed to the at least one heating conductor (18, 20) with an electrical insulating material (76) in the middle.

13. The exhaust heater according to claim 1 or 2, characterized in that, The electrical insulating material (76) is magnesium oxide.

14. The exhaust heater according to claim 1 or 2, characterized in that, At least one support element (68) is arranged with its longitudinal axis (S) parallel to the longitudinal axis (L) of the exhaust heater.

15. The exhaust heater according to claim 14, characterized in that, Each support element (68) is arranged with its longitudinal axis (S) parallel to the longitudinal axis (L) of the exhaust heater.

16. The exhaust heater according to claim 1 or 2, characterized in that, The bracket housing (32) and the bracket pin (70) and bracket sleeve (74) of the at least one bracket element (68) are constructed of metal material, and / or the bracket pin (70) of the at least one bracket element (68) is connected to the bottom of the housing (34) by material locking.

17. The exhaust heater according to claim 1 or 2, characterized in that, The bracket housing (32) and the bracket pins (70) and bracket sleeves (74) of each bracket element (68) are constructed of metal material, and / or the bracket pins (70) of each bracket element (68) are connected to the bottom of the housing (34) by material locking, and / or the bracket sleeves (74) of each bracket element (68) are connected to the at least one heating conductor (18, 20) by material locking.

18. The exhaust heater according to claim 7, characterized in that, At least two heating conductor corrugated areas (F1, F2, F3, F4) provided as separate heating conductor material parts (78, 80, 84, 86) are electrically connected to each other by means of at least one support element (68) that supports the heating conductor corrugated areas on the support housing (32).

19. The exhaust heater according to claim 1 or 2, characterized in that, The support housing (32) has a circumferential wall (36) that is radially externally connected to the bottom (34) of the housing.

20. The exhaust heater according to claim 19, characterized in that, The support housing (32) is can-shaped with a housing bottom (34) and a circumferential wall (36), and the at least one heating conductor (18, 20) is not covered by the support arrangement structure (30) on the axial second side (22) or / and the at least one heating conductor (18, 20) extends axially beyond the circumferential wall (36) on the axial second side (22).

21. An exhaust system for an internal combustion engine, comprising at least one exhaust treatment unit (24) and at least one exhaust heater (14) upstream of the at least one exhaust treatment unit (24) along the main exhaust flow direction (A) relative to the at least one exhaust treatment unit (24).

22. The exhaust device according to claim 21, characterized in that, The at least one exhaust treatment unit (24) is configured as a catalyst and / or a particulate filter.

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