Exhaust equipment

Abstract

The invention relates to an exhaust gas device for an internal combustion engine, comprising an exhaust gas heater housing (16), at least one exhaust gas heater (20) arranged in the exhaust gas heater housing (16), an exhaust gas treatment unit housing (22) connected to a downstream end region (18) of the exhaust gas heater housing (16) at an upstream end region (24) thereof, at least one exhaust gas treatment unit (26) arranged in the exhaust gas treatment unit housing (22), wherein the at least one exhaust gas heater (20) comprises at least one connecting element (48, 50) which extends in a downstream direction towards the exhaust gas treatment unit housing (22) and overlaps the upstream end region (24) of the exhaust gas treatment unit housing (22) or / and an exhaust gas treatment unit (26) arranged in the upstream end region (24) of the exhaust gas treatment unit housing (22) in the exhaust gas main flow direction (A).

Description

Technical Field

[0001] This invention relates to an exhaust device for an internal combustion engine. Background Technology

[0002] In order to consider in the exhaust system provided for an internal combustion engine that, when the internal combustion engine is started, the system areas through which the exhaust flows, in particular the exhaust treatment units such as catalytic converters or particulate filters, can be quickly brought to operating temperature so that the reactions that would normally be carried out at relatively high temperatures by such exhaust treatment units can be utilized as quickly as possible after the internal combustion engine is started, it is known that an exhaust heater is installed upstream of the exhaust treatment unit in such an exhaust system. This exhaust heater transfers heat to the exhaust flow ejected from the internal combustion engine so that the heat is transferred by means of the exhaust flow to the downstream system areas and the system areas are brought to operating temperature more quickly. Summary of the Invention

[0003] The objective of this invention is to provide an exhaust device with a compact construction that effectively utilizes available structural space.

[0004] According to the present invention, the task is solved by an exhaust device for an internal combustion engine according to the present invention. The exhaust device includes:

[0005] Exhaust heater housing;

[0006] At least one exhaust heater is provided in the exhaust heater housing;

[0007] The upstream end region is connected to the exhaust treatment unit housing on the downstream end region of the exhaust heater housing;

[0008] At least one exhaust treatment unit is disposed in the exhaust treatment unit housing.

[0009] Wherein, at least one exhaust heater includes at least one connecting element that extends downstream toward the exhaust treatment unit housing and overlaps with the upstream end region of the exhaust treatment unit housing and / or the exhaust treatment unit disposed in the upstream end region of the exhaust treatment unit housing along the main exhaust flow direction.

[0010] By extending such connecting elements to the downstream system region adjacent to or overlapping with it in the direction of the main exhaust flow, these interconnected system regions—that is, the exhaust heater housing with components disposed therein and the exhaust treatment unit housing with components disposed therein—can be arranged closer to each other. This results in a compact structural form or efficient utilization of the structural space available for such exhaust equipment.

[0011] To provide space for at least one connecting element, it is proposed that the at least one connecting element has an overlapping extension section that overlaps with the exhaust treatment unit and / or the exhaust treatment unit housing along the main exhaust flow direction, and the exhaust treatment unit housing does not cover the exhaust treatment unit disposed in the upstream end region of the exhaust treatment unit housing on its outer peripheral side, at least in the extension region of the overlapping extension section of the at least one connecting element.

[0012] For this purpose, the exhaust treatment unit housing may, for example, have an overlapping extension section with an upstream opening in the extension region of the overlapping extension section of the at least one connecting element to accommodate a void.

[0013] In order to connect the exhaust heater to a power source that is usually located outside the exhaust equipment, the exhaust heater housing may be provided with contact units for connecting the connecting elements by means of electrical contacts.

[0014] In order to make efficient use of the available structural space, at least one, preferably each, contact unit arranged in a manner that is matched with the connecting element may also be arranged on the section of the exhaust heater housing that overlaps with the exhaust treatment unit housing and / or the exhaust treatment unit arranged in the upstream end region of the exhaust treatment unit housing along the main exhaust flow direction.

[0015] To avoid interference between the connecting elements and the exhaust treatment unit, the exhaust heater housing is provided with a contact unit support protrusion in a manner that is configured with at least one, preferably each, contact unit, and at least one, preferably each, contact unit is supported on the exhaust heater housing in the area of ​​the configured contact unit support protrusion.

[0016] Here, at least one, preferably each contact unit support protrusion, may at least partially overlap with the upstream end region of the exhaust treatment unit housing or / and the exhaust treatment unit disposed in the upstream end region of the exhaust treatment unit housing along the main exhaust flow direction.

[0017] To enable the simple connection and positioning of two housings, namely an exhaust heater housing and an exhaust treatment unit housing, that are sequential or connected to each other along the main exhaust flow direction, in a defined flow guide, the exhaust heater housing extends along the longitudinal axis of the exhaust heater housing in a housing section that houses the at least one exhaust heater and provides the downstream end region, and the exhaust treatment unit housing extends along the longitudinal axis of the exhaust treatment unit housing in a housing section that houses the at least one exhaust treatment unit and provides the upstream end region.

[0018] Here, a compact structural form can be supported by positioning the exhaust treatment unit housing in such a way that its upstream end region is embedded in the downstream end region of the exhaust heater housing.

[0019] The at least one exhaust heater may include at least one heat conductor, wherein a first connecting element of the connecting elements is electrically connected to or provides the first connecting segment of the at least one heat conductor, and / or a second connecting element of the connecting elements is electrically connected to or provides the second connecting segment of the at least one heat conductor.

[0020] To efficiently heat the exhaust gas flowing in the exhaust system, the at least one exhaust heater may include two heat conductors electrically connected in series and arranged sequentially along the main exhaust flow direction. Here, one of the heat conductors arranged sequentially along the main exhaust flow direction may have a first connecting section, and the other heat conductor arranged sequentially along the main exhaust flow direction may have a second connecting section.

[0021] In order to heat the exhaust gas across the entire flow cross-section, at least one, preferably each heat conductor, can be constructed in a plate-like manner, extending substantially orthogonally to the main flow direction of the exhaust gas. Attached Figure Description

[0022] The invention will then be described in detail with reference to the accompanying drawings. In the drawings:

[0023] Figure 1 A longitudinal sectional view of the exhaust heater housing of an exhaust device is shown, the exhaust device having an exhaust treatment unit housing installed in the downstream end region of the exhaust heater housing;

[0024] Figure 2 A perspective view of an exhaust heater housing is shown, the housing having an exhaust heater disposed in its downstream end region. Detailed Implementation

[0025] exist Figure 1 The longitudinal section view shows a section of the exhaust system, generally designated 10. The exhaust system 10 is located in... Figure 1 The section shown illustrates, for example, an exhaust heater housing 16 constructed with two housing bearings 12, 14, which supports an exhaust heater, generally indicated by 20, in a downstream, generally cylindrical downstream end region 18 that extends substantially along the longitudinal axis L1 of the exhaust heater housing.

[0026] The exhaust treatment unit housing 22 is connected to the exhaust heater housing 16 of the exhaust device 10 in the downstream end region 18 of the exhaust heater housing. This exhaust treatment unit housing has an upstream end region 24 that is substantially cylindrical and extends along the longitudinal axis L2 of the exhaust treatment unit housing. The longitudinal axes L1 and L2 of the exhaust heater housing and the exhaust treatment unit housing can be arranged parallel to each other, particularly coaxially, in the interlocking end regions 18 and 24. The exhaust heater housing 16 and the exhaust treatment unit housing 22 can be fixed and hermetically connected to each other by welding in the areas where they overlap, and in these end regions, the exhaust heater housing 16 and the exhaust treatment unit housing 22 can be constructed, for example, with a circular cross-section.

[0027] An exhaust treatment unit 26, for example, constructed as a monolith, is disposed in the exhaust treatment unit housing 22 and is fixedly held in the exhaust treatment unit housing 22 by a support arrangement 28, such as one or more fiber pads or the like, that surrounds the exhaust treatment unit substantially over its entire periphery, such that preferably the upstream end of the exhaust treatment unit 26 is substantially flush with the upstream end of the exhaust treatment unit housing 22.

[0028] The exhaust treatment unit 26 can be configured as, for example, an oxidation catalyst or a particulate filter, and the individual pieces of the exhaust treatment unit 26 can be coated and / or constructed with a catalytically effective material. Exhaust gas flowing from the exhaust heater housing 16 through the exhaust heater 20 to the exhaust treatment unit 26, passing substantially in the adjacent region on the exhaust heater housing 16 toward the exhaust treatment unit housing 22, corresponding, for example, to the orientation of two longitudinal axes L1, L2 that are coaxial with each other, can enter its porous structure in the region of the exhaust treatment unit 26 facing the exhaust heater 20 and undergo the catalytic reaction to be provided by the exhaust treatment unit 26 on the surface formed therein.

[0029] The exhaust heater 20, in the illustrated design example, includes two heat conductors 32, 34 arranged sequentially along the main exhaust flow direction A or along the longitudinal axis L1 of the exhaust heater housing. Each of the heat conductors 32, 34 is plate-shaped and thus extends substantially in a direction or plane orthogonal to the longitudinal axis L1 of the exhaust heater housing or to the main exhaust flow direction A. The two heat conductors 32, 34 can be produced, for example, by separating them from a flat blank of metallic material, which is heated when a voltage is applied and a current flows through it. Alternatively, the heat conductors 32, 34 can also be provided by spirally or corrugatedly wound wire-like heat conductors, the structure of which can be such that they extend, for example, in a conical or truncated cone shape along the longitudinal axis L1 of the exhaust heater housing.

[0030] The exhaust heater 20 also includes a support arrangement 36 via which the exhaust heater is fixed to the inner side of the exhaust heater housing 16. The support arrangement 36 includes, on both axial sides of the two heat conductors 32, 34, substantially plate-shaped support elements 38, 40, i.e., substantially in a plane orthogonal to the longitudinal axis L1 of the exhaust heater housing, constructed, for example, of shaped or sheet metal elements separated from flat material blanks. One of the two support elements 38, 40 is axially bent in its outer peripheral region and fixed to the inner surface of the exhaust heater housing 16, for example, by material locking, such as welding, at this bent region.

[0031] For electrical insulation, insulating elements, for example made of ceramic material, are provided between the two heat conductors 32, 34 and between the heat conductors and the support elements 38, 40. The exhaust heater 20 is fixedly held together by a plurality of bolts or the like through the support elements 38, 40, the heat conductors 32, 34 and the insulating elements that electrically insulate them about each other.

[0032] In the design example shown, the two heat conductors 32, 34 are connected in series with each other. This means that, for example, each of the two heat conductors 32, 34, constructed using heat conductor segments extending in a corrugated structure, has a connection end that is electrically connected to the connection end of the corresponding other heat conductor. Each heat conductor 32, 34 then has another connection end 42, 44, through which the two heat conductors 32, 34 connected in series are connected via a... Figure 1 The visible contact arrangement 46 is electrically connected to a power source, such as a battery installed in a vehicle.

[0033] To create this conductive connection, connecting elements 48 and 50, for example, constructed from sheet metal, are provided to mate with each connecting end 42, 44. Each connecting element 48, 50 has connecting sections 52, 54, for example, joined to the corresponding connecting ends 42, 44 of the heat conductors 32, 34 by material locking, i.e., fusion welding or brazing, and overlapping extending sections 56, 58, which bend from the connecting sections along the main exhaust flow direction A or the longitudinal axes L1, L2 and thus extend toward the exhaust treatment unit housing 22. The two overlapping extending sections 56, 58 axially protrude from the support arrangement structure 36 and extend circumferentially adjacent to each other along the main exhaust flow direction A or the two longitudinal axes L1, L2 into the extension region of the contact arrangement structure 46 or also the exhaust treatment unit housing 22. To achieve this, the exhaust treatment unit housing 22 has an overlapping extension section receiving void 60 that opens upstream along the longitudinal axis L2 of the exhaust treatment unit housing, in a manner that mates with the two overlapping extension sections 56, 58. In the region of the overlapping extension section receiving void 60, the exhaust treatment unit 26 is not covered on its outer periphery by the exhaust treatment unit housing 22. The support arrangement structure 28 also has a void in this region to provide space for accommodating the overlapping extension sections 56, 58. The overlapping extension sections thus overlap axially with the exhaust treatment unit 26 disposed in the upstream end region 24 of the exhaust treatment unit housing 22 and overlap axially or circumferentially with the exhaust treatment unit housing 22.

[0034] The contact arrangement structure 46 includes conductive contact elements 64, 66 supported on the exhaust heater housing 16 by a contact support arrangement structure 62, in a manner that corresponds to each overlapping extension section 56, 58. The end sections of the contact elements 64, 66 exposed inside the exhaust heater housing 16 are inserted, for example, into openings respectively provided in the corresponding overlapping extension sections 56, 58 and are fixedly connected to the provided overlapping extension sections 56, 58 in that region by material locking, such as fusion welding or brazing.

[0035] In order to allow the overlapping extension sections 56, 58 to be arranged with a sufficient axial distance from the outer side of the exhaust treatment unit 26, a radially protruding portion is provided on the exhaust heater housing 16 in the region where the contact support arrangement structure 62 is supported, providing a contact unit support protrusion 68. This protruding portion at least partially overlaps with the upstream end region 24 of the exhaust treatment unit housing 22. Consequently, in the region of the contact unit support protrusion 68, the contact arrangement structure 46 is positioned radially further outward. Thus, a sufficient structural space is provided for connecting each of the overlapping extension sections 56, 58 to the electrical contacts of each of the contact elements 64, 66 that are provided with corresponding contact units 70 or 72 in conjunction with the contact support arrangement structure 62.

[0036] By providing connecting elements 48 and 50, the following possibility is given: the positioning of the contact arrangement structure 46 can be selected substantially independently of the positioning of the exhaust heater 20 along the longitudinal axis L1 of the exhaust heater housing. Simultaneously, it is possible to further shift the exhaust treatment unit 26 upstream toward the exhaust heater 20, thereby effectively utilizing the available structural space. Since the contact arrangement structure 46 is further radially outwardly shifted, mutual interference between the connecting elements 48 and 50 and the exhaust treatment unit 26 is also avoided, taking into account the unavoidable manufacturing tolerances that arise when constructing such an exhaust device 10.

[0037] Finally, it should be noted that very different modifications can be made to the previously described construction without departing from the essence of the invention. Thus, the exhaust treatment unit housing 22 can, for example, be constructed in principle to be shorter such that the exhaust treatment unit 26 protrudes beyond the exhaust treatment unit housing 22 throughout its entire upstream end region 24 and is thereby not covered by the exhaust treatment unit housing 22 not only in the area of ​​the gap but throughout the entire circumferential region. The two connecting elements 48, 50 or their overlapping extension sections 56, 58 can be positioned with a large circumferential distance between them, such that the exhaust treatment unit housing 22 has a separate overlapping extension section receiving recess 60, for example, in a manner that mates with each of the said overlapping extension sections 56, 58. The contact units 70, 72 or their contact elements 64, 66 can also be arranged with a large circumferential distance and, for example, also in different axial regions of the exhaust heater housing 16 and, for example, via a separate contact support arrangement 62 on a separate contact unit support protrusion 68 disposed on the separate contact support arrangement.

[0038] It should be further noted that, for example, the exhaust heater 20 can also utilize a single, for example, substantially plate-shaped, heat conductor, or it can have more than two successive heat conductors along the main exhaust flow direction A. In designs with multiple heat conductors, the heat conductors can also be connected in parallel with each other, such that each connecting element 48, 50 providing connecting sections 74, 76 is then electrically connected to multiple connecting ends of the heat conductor. Alternatively, connecting elements 48, 50, or at least one of the connecting elements 48, 50, can be constructed as an integrated component of one or, if necessary, different heat conductors, such that the corresponding connecting sections 74, 76 for connection to one of the contact units 70, 72 are not provided by separate components, but by sections of the heat conductor that also provide corresponding connecting ends 42, 44.

Claims

1. Exhaust-gas system for an internal combustion engine, comprising: - an exhaust-gas heater housing (16), - at least one exhaust-gas heater (20) arranged in the exhaust-gas heater housing (16), - an exhaust-gas treatment unit housing (22) which is connected to a downstream end region (18) of the exhaust-gas heater housing (16) at an upstream end region (24) thereof, - at least one exhaust-gas treatment unit (26) arranged in the exhaust-gas treatment unit housing (22), - wherein the at least one exhaust-gas heater (20) comprises at least one connecting element (48, 50) which extends in a downstream direction towards the exhaust-gas treatment unit housing (22) and overlaps the upstream end region (24) of the exhaust-gas treatment unit housing (22) or / and an exhaust-gas treatment unit (26) arranged in the upstream end region (24) of the exhaust-gas treatment unit housing (22) in the main exhaust-gas flow direction (A).

2. The exhaust apparatus according to claim 1, characterized by The at least one connecting element (48, 50) has an overlap extension section (56, 58) which overlaps the exhaust-gas treatment unit (26) or / and the exhaust-gas treatment unit housing (22) in the main exhaust-gas flow direction (A), and the exhaust-gas treatment unit housing (22) does not cover the exhaust-gas treatment unit (26) arranged in the upstream end region (24) of the exhaust-gas treatment unit housing (22) on its peripheral side at least in the extension region of the overlap extension section (56, 58) of the at least one connecting element (48, 50).

3. The exhaust apparatus according to claim 2, characterized by The exhaust-gas treatment unit housing (22) has an overlap extension section accommodation recess (60) which opens in an upstream direction in the extension region of the overlap extension section (56, 58) of the at least one connecting element (48, 50).

4. The exhaust apparatus according to any one of claims 1 to 3, characterized by There is provided an electrical contact unit (70, 72) which is arranged on the exhaust-gas heater housing (16) in a manner which is matched to each connecting element (48, 50) and which contacts the connecting element.

5. The exhaust apparatus according to claim 4, characterized by At least one contact unit (70, 72) which is arranged in a manner which is matched to a connecting element (48, 50) is arranged on the exhaust-gas heater housing (16) on a section which overlaps the exhaust-gas treatment unit housing (22) or / and an exhaust-gas treatment unit (26) arranged in the upstream end region (24) of the exhaust-gas treatment unit housing (22) in the main exhaust-gas flow direction (A).

6. The exhaust apparatus according to claim 4, characterized by Each contact unit (70, 72) which is arranged in a manner which is matched to a connecting element (48, 50) is arranged on the exhaust-gas heater housing (16) on a section which overlaps the exhaust-gas treatment unit housing (22) or / and an exhaust-gas treatment unit (26) arranged in the upstream end region (24) of the exhaust-gas treatment unit housing (22) in the main exhaust-gas flow direction (A).

7. The exhaust apparatus according to claim 4, characterized by The exhaust-gas heater housing (16) has a contact unit support projection (68) in a manner which is matched to at least one contact unit (70, 72), and at least one contact unit (70, 72) is supported on the exhaust-gas heater housing (16) in the region of the matched contact unit support projection (68).

8. The exhaust apparatus according to claim 4, characterized by The exhaust gas heater housing (16) has a contact unit support protrusion (68) in a manner fitted to each contact unit (70, 72), and each contact unit (70, 72) is supported on the exhaust gas heater housing (16) in the region of the fitted contact unit support protrusion (68).

9. The exhaust apparatus according to claim 7, characterized by At least one contact unit support protrusion (68) at least partially overlaps the upstream end region (24) of the exhaust gas treatment unit housing (22) or / and an exhaust gas treatment unit (26) arranged in the upstream end region (24) of the exhaust gas treatment unit housing (22) in the exhaust gas main flow direction (A).

10. The exhaust apparatus according to claim 8, characterized by Each contact unit support protrusion (68) at least partially overlaps the upstream end region (24) of the exhaust gas treatment unit housing (22) or / and an exhaust gas treatment unit (26) arranged in the upstream end region (24) of the exhaust gas treatment unit housing (22) in the exhaust gas main flow direction (A).

11. The exhaust apparatus according to any one of claims 1 to 3, characterized by The exhaust gas heater housing (16) is elongated in the direction of an exhaust gas heater housing longitudinal axis (L1) in a housing section thereof which accommodates the at least one exhaust gas heater (20) and which provides the downstream end region (18), and the exhaust gas treatment unit housing (22) is elongated in the direction of an exhaust gas treatment unit housing longitudinal axis (L2) in a housing section thereof which accommodates the at least one exhaust gas treatment unit (26) and which provides the upstream end region (24).

12. The exhaust apparatus according to any one of claims 1 to 3, characterized by The exhaust gas treatment unit housing (22) is positioned in a manner which engages with its upstream end region (24) into the downstream end region (18) of the exhaust gas heater housing (16).

13. The exhaust apparatus according to any one of claims 1 to 3, characterized by The at least one exhaust gas heater (20) comprises at least one heat conductor (32, 34), and a first connection element (48) of the connection elements is electrically conductively connected to or provides a first connection section (74) of the at least one heat conductor (32, 34), or / and a second connection element (50) of the connection elements is electrically conductively connected to or provides a second connection section (76) of the at least one heat conductor (32, 34).

14. The exhaust apparatus according to claim 13, characterized by The at least one exhaust gas heater (20) comprises two heat conductors (32, 34) which are electrically connected in series with one another and which are arranged one after the other in the exhaust gas main flow direction (A), and the first connection section (74) is provided for one of the heat conductors (32, 34) arranged one after the other in the exhaust gas main flow direction (A), and the second connection section (76) is provided for the other of the heat conductors (32, 34) arranged one after the other in the exhaust gas main flow direction (A).

15. The exhaust apparatus according to claim 13, characterized by At least one heat conductor (32, 34) is plate-shaped in a manner which extends orthogonally to the exhaust gas main flow direction (A).

16. The exhaust apparatus according to claim 13, characterized by Each heat conductor (32) is plate-shaped in a manner which extends orthogonally to the exhaust gas main flow direction (A).

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