Connecting unit for connecting an electrical supply line to a connecting element of a heatable exhaust system

Abstract

The present invention relates to a connecting unit for connecting an electrical supply line to a connecting element of a heatable exhaust device, comprising a connecting unit housing, the connecting unit housing having a connecting element-receiving area extending in the direction of a first housing axis and a supply line-receiving area extending in the direction of a second housing axis, the connecting element-receiving area being open in a first axial connecting element-receiving area-end area for receiving a connecting element extending from the exhaust device and being closed in a second axial connecting element-receiving area-end area, the supply line-receiving area being open in the first axial supply line-receiving area-end area towards the connecting element-receiving area and being open in a second supply line-receiving area-end area for receiving an electrical supply line.

Description

Technical Field

[0001] The invention relates to a connecting unit for connecting an electrical supply line to a connecting element of a heatable exhaust gas system. Background Art

[0002] In order to quickly bring exhaust gas treatment units (e.g., particle filters, catalytic converters, in particular oxidation catalytic converters or SCR catalytic converters) arranged in an exhaust gas system of a vehicle internal combustion engine, in particular during the start phase of the combustion operation of the internal combustion engine, to a temperature suitable for the exhaust gas treatment to be carried out, it is known to assign electrically operated heating devices to such exhaust gas treatment units. These heating devices can be designed, for example, in the form of exhaust gas heaters with heating conductors arranged upstream of such exhaust gas treatment units, by which the exhaust gas to be flowed to the exhaust gas aftertreatment unit is heated and the heat absorbed in the exhaust gas is transferred to the exhaust gas treatment unit that follows downstream.

[0003] In order to be able to connect such a heating device to an electrical energy source, usually to a battery or an onboard electrical system provided in the vehicle, a connecting element is provided on the exhaust gas conducting component receiving such a heating device, to which an electrical supply line can be connected. The connection of the supply line to the provided connecting element is carried out on the outer side of the exhaust gas conducting component receiving such a heating device, which is substantially exposed to the outside environment, so that the area in which the connection is established is exposed to environmental influences. Summary of the invention

[0004] The object of the present invention is to provide a connecting unit for connecting an electrical supply line to a connecting element of a heatable exhaust system, with which connecting unit reliable shielding of the area in which the electrical connection between supply line and connecting element is established is ensured in a structurally simple design.

[0005] According to the invention, the object is achieved by a connecting unit for connecting an electrical supply line to a connecting element of a heatable exhaust device, the connecting unit comprising a connecting unit housing having a connecting element-receiving area extending in the direction of a first housing axis and a supply line-receiving area extending in the direction of a second housing axis, the connecting element-receiving area being open in a first axial connecting element-receiving area-end area for receiving a connecting element extending at the exhaust device and being closed in a second axial connecting element-receiving area-end area, the supply line-receiving area being open in a first axial supply line-receiving area-end area towards the connecting element-receiving area and being open in a second supply line-receiving area-end area for receiving the electrical supply line.

[0006] By encapsulating the two electrically connected components, namely the connecting element and the supply line, the connection unit housing shields the region in which the electrically conductive connection is produced from environmental influences, thereby also avoiding the risk of short circuits due to water spray or the like.

[0007] In a design solution that can also be simply implemented with a relatively complex shape of the connecting unit housing, it is proposed that the connecting unit housing is constructed with two housing shells that are connected to each other in the connecting edge area, wherein each housing shell has a first housing shell section for providing a connecting element-receiving area and a second housing shell section for providing a supply line-receiving area.

[0008] For reasons of mechanical strength and thermal resistance, the connecting unit housing can be formed at least partially from sheet material.

[0009] In order to achieve a reliable shielding effect in the area adjacent to the outer periphery of the exhaust device, it is recommended that: the connecting unit housing has an exhaust device connecting edge extending radially outward relative to the first housing axis in the first axial connecting element-receiving area-end area, and the exhaust device connecting edge has an exhaust device connecting surface to be positioned which annularly surrounds the first housing axis and faces the corresponding connecting surface of the exhaust device.

[0010] In this case, for a structurally simple embodiment of the connecting element housing, the exhaust system connecting surface can lie in a plane which is orthogonal to the first housing axis.

[0011] In particular, when the exhaust gas guiding component, on which the connecting element to be electrically connected projects outwardly, is tubular in design and therefore has a curved outer circumference, it is advantageous to achieve a good shielding effect if the exhaust gas device connecting surface is curved, preferably about a bending axis orthogonal to the first housing axis. The bending axis can correspond, for example, to the longitudinal center axis of the tubular exhaust gas guiding component.

[0012] In order to provide access to the region in which the electrical connection is established between the connecting element and the associated supply line, it is proposed that the connecting element receiving region is closed at the second axial connecting element receiving region end region by a cover.

[0013] The cover is preferably held on the connecting unit housing by means of a positive fit, so that it can be easily and repeatedly removed from the connecting unit housing or mounted thereon in order to establish or release the connection.

[0014] In order to provide both electrical and thermal insulation between the connecting unit housing and the connecting element, a first insulating element can be provided in the connecting element receiving region, which supports the connecting unit housing relative to the connecting element to be received in the connecting element receiving region.

[0015] Since the insulating element and the connecting unit housing usually consist of different materials, it is proposed that the first insulating element is held on the connecting unit housing by means of a positive fit.

[0016] In order to produce a supporting interaction with respect to the connecting element, the first insulation element can have a connecting element receiving opening.

[0017] When the first insulating element is composed of a ceramic material, it not only provides excellent electrical insulation, but also excellent thermal insulation. Other materials such as mica materials can also be used to construct such an insulating element.

[0018] In order to also provide electrical and thermal insulation between the connecting element housing and the supply line, it is proposed that a second insulating element is provided in the connecting element receiving region, which second insulating element supports the connecting unit housing relative to the supply line to be received in the supply line receiving region.

[0019] In this case, it is advantageous for the use of different materials if the second insulating element is held on the connecting element housing by a form-fitting structure. The second insulating element can have a supply line receiving opening for support relative to the connecting element. The second insulating element can also be constructed with a ceramic material or a similar material (for example a mica material).

[0020] For a compact design of the connecting unit it is proposed that the second housing axis is substantially orthogonal to the first housing axis.

[0021] The present invention also relates to an exhaust device for an internal combustion engine, the exhaust device comprising: an exhaust guide component; at least one connecting element carried on the exhaust guide component, the connecting element being used to connect an electrical supply line; and a connecting unit associated with the at least one connecting element and constructed according to the present invention, the connecting unit being used to connect the electrical supply line assigned to the at least one connecting element to the connecting element.

[0022] In order to be able to establish electrical contact between the connecting element and the supply line within the connecting unit housing, the at least one connecting element can be received in a connecting element receiving region of a connecting unit assigned to the connecting element, and the supply line assigned to the at least one connecting element can be received in a supply line receiving region of a connecting unit assigned to the connecting element, so that the connection end of the supply line extends into the connecting element receiving region and is electrically conductively connected to the connecting element. The electrical contact is thus established essentially in the connecting element receiving region.

[0023] For a simple but nevertheless stable electrical connection, a connecting eye can be provided on the connecting end of the supply line, which eye is pushed onto the connecting element and is fixed thereto by a screw connection.

[0024] In order to stably hold the connection unit on the exhaust system, it is proposed that the connection unit is supported relative to the exhaust system, preferably relative to the connection element, by a first insulating unit. In particular, it can be provided that the first insulating element is held on the exhaust system by means of a threaded mechanism that fixes the supply line on the connection element.

[0025] The exhaust system connecting surface can lie opposite the curved outer circumferential surface of the exhaust gas conducting component which provides the counter connecting surface and can thus be adapted to the curved outer circumferential surface of the exhaust gas conducting component.

[0026] In an alternative embodiment, it can be provided that the exhaust system connecting surface lies opposite an unbent counter-connecting surface on the connecting element or on the exhaust gas conducting component. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be described in detail below with the aid of the accompanying drawings.

[0028] Figure 1 A sectional view of an exhaust system with a connecting unit for connecting a supply line to a connecting element of the exhaust system is shown;

[0029] Figure 2 An alternative design is shown with Figure 1 The corresponding diagram;

[0030] Figure 3 Shown along Figure 1 The viewing direction III shows Figure 1 A top view of the connection unit. DETAILED DESCRIPTION

[0031] Figure 1A first embodiment of a connection unit, generally designated by 10, is shown, by which an electrical supply line 12 can be connected to a connection element 14 of an exhaust system, generally designated by 16. The exhaust system 16 can include an exhaust gas-conducting component 18 of tubular design, in which the exhaust gas flows toward an exhaust gas treatment unit, such as a particle filter, an oxidation catalytic converter or an SCR catalytic converter. In order to heat the exhaust gas flowing toward the exhaust gas treatment unit or to heat the exhaust gas treatment unit, an electrically operated heating device can be provided in the exhaust gas-conducting component 18. The heating device can include a heating conductor, which is heated when a voltage is applied and thus outputs heat to its surroundings. The two connection ends of the heating conductor are each electrically connected to a connection element 14 carried on the exhaust gas-conducting component 18. Each such connection element 14 can, for example, include a housing element 20, which is fixed to the exhaust gas-conducting component 18 in a gas-tight manner, for example by welding, and a conductor element 22 held in the housing element in an electrically insulating manner, the end 24 of which protrudes outwardly beyond the exhaust gas-conducting component 18 or the housing element 20 being electrically connected to the supply line 12.

[0032] For this purpose, the supply line 12 has a connecting eye 28 at the connecting end 26, which is pushed onto the end 24 of the conductor element 22 provided with an external thread and is fixed thereon to the connecting element 14 by means of a threaded mechanism 30 (a nut in the illustrated embodiment) in the manner described below to produce an electrical connection.

[0033] The connecting unit 10 comprises a connecting unit housing 32, which in the illustrated embodiment is constructed with two housing shells 34, 36, each of which is constructed as a sheet metal formed part. The two housing shells 34, 36, which are constructed complementary to each other or essentially mirror-symmetrically, together provide a connecting element receiving area 38 extending in the direction of the first housing axis G1 and a supply line receiving area 40 extending along the second housing axis G2. For this purpose, each of the two housing shells 34, 36 has a first housing shell section 34', 36' for providing the connecting element receiving area 38 and a second housing shell section 34", 36". For providing the supply line receiving area 40. The connecting element receiving area 38 and the supply line receiving area 40 or their respective longitudinal axes provided by the housing axes G1, G2 are preferably arranged essentially orthogonally to each other, so that in principle the connecting unit housing 32 has an approximately right-angled shape.

[0034] The two housing shells 34 , 36 provided as sheet metal parts can be fixedly connected to one another in their mutually adjoining connecting edge regions 42 , for example by flanging and / or by material bonding, ie, for example by welding.

[0035] In the first axial connecting element receiving region end region 44, the connecting unit housing 32 or the connecting element receiving region 38 is open in the axial direction in order to receive therein the connecting element 14. In the first axial connecting element receiving region end region 44, an exhaust system connecting edge 46 is provided on the connecting unit housing 32, which radially projects outwards relative to the first housing axis G2 and has an exhaust system connecting surface 50 facing the outer circumferential surface 48 of the exhaust gas guide component 18 or the exhaust gas device 16. In the case of a tubular, i.e. essentially circular, design of the exhaust gas guide component 18, the connecting edge 46 or the exhaust system connecting surface provided thereon and essentially annularly surrounding the first housing axis G1 is preferably designed to be curved about a bending axis K, wherein the bending axis K can essentially correspond to the longitudinal center axis of the exhaust gas guide component 18 and thus also provide a bending axis of the outer circumferential surface of the exhaust gas guide component 18 in the region of the connecting unit housing 32, which provides the corresponding connecting surface 52. When the connecting unit housing 32 is fastened to the exhaust system 16 , a tight connection of the connecting edge 46 to the exhaust gas conducting component 18 is thus achieved, wherein in this state the connecting edge 46 can, for example, touch the exhaust gas conducting component 18 or can leave a small gap-like clearance relative to the exhaust gas conducting component.

[0036] At the second axial connecting element receiving region end region 54, the connecting element receiving region 38 is closed by a cover 56, which is also made of sheet material, for example. The cover 56 can be fixed to the connecting unit housing 32, for example, by form fit, in particular by locking, so that it can be removed from the connecting unit housing 32 or reattached thereto in order to repeatedly establish and release the electrically conductive connection between the supply line 12 and the connecting element 14.

[0037] The supply line receiving region 40 is open in a first axial supply line receiving region end region 58 toward the connecting element receiving region 38. In a second axial supply line receiving region end region 60, the supply line receiving region 40 or the connecting unit housing 32 forms a guide passage 62 adapted to the outer dimensions of the supply line 12, so that in this region a substantially closed connection of the connecting unit housing 32 to the supply line 12 is achieved to prevent the ingress of spray water or dirt.

[0038] In the connection element receiving region 38 of the connection unit housing 32, a first insulating element 64 of annular design, for example, made of a ceramic material, is arranged. The first insulating element is held in a positively locking manner on the connection unit housing 32 by two flange-like recessed shaped portions 66, 68 formed on both sides of the connection element in the axial direction, so that a stable connection between the first insulating element 64 and the connection unit housing 32 is achieved despite the different construction materials for the two components. The conductor element 22 of the connection element 14 passes through the connection element receiving opening 70 in the first insulating element 64. The first insulating element 64 is supported in the axial direction on the connection element 14 (for example, on the outer cover element 20 of the connection element). The connection eyelet 28 is pushed onto the section of the conductor element 22 that protrudes beyond the first insulating element 64 and is pressed against the first insulating element 64 by the screw mechanism 30, whereby the first insulating element 64 is again pressed against the connection element 14 or overall against the exhaust system 16 and the connection unit 10 is thus held in a defined manner relative to the exhaust system 16. As already mentioned, in this state the terminal edge 46 can rest against the outer circumferential surface 48 of the exhaust gas conducting component 18 or can be at a gap-like distance from the outer circumferential surface.

[0039] The second insulating element 72 is received in the supply line receiving region 40. The second insulating element is also fixedly held on the connecting unit housing 32 by a positive fit between two flange-like recessed shaped portions 74, 76 and provides a supply line receiving opening 78 through which the supply line 12 extends and is thereby held relative to the connecting unit housing 32 in the region of its length that runs through the supply line receiving region 40.

[0040] The two insulating elements 64, 72 hold the connecting unit 10 in a stable electrically insulated manner and also in a thermally insulated manner relative to the connecting element 14 or the supply line 12 electrically connected thereto. Thus, the inevitable increase in temperature of the connecting element 14 and the supply line 12 thereto during operation does not lead to an excessive increase in temperature of the connecting unit 10.

[0041] exist Figure 2 An alternative embodiment is shown in . In this embodiment, the structure of the connecting unit 10 corresponds essentially to the previously described structure, so that reference can be made to these embodiments.

[0042] Corresponding to the connecting element 14, a base 80 is provided which provides a corresponding connecting surface 52. The base can, for example, form part of the connecting element 14, in particular part of its outer shell element 20, and thus be designed or connected, for example, in one piece, but can alternatively also be provided on the exhaust gas guide component 18.

[0043] The corresponding connection surface 52 arranged on the base 80 annularly surrounds the first housing axis G1 and is substantially orthogonal to the first housing axis. Accordingly, the exhaust device connection surface 50 arranged on the connection edge 46 is also substantially orthogonal to the first housing axis G1, so that Figure 2 The exhaust system connecting surface 50 is shown lying opposite a counter-connecting surface 52 at a small gap-like distance or supported thereon.

[0044] Due to the essentially orthogonal orientation of the exhaust system connecting surface 50 relative to the first housing axis G1 , the design of the connecting element housing 32 or essentially the two housing shells 34 , 36 providing it can be realized in a simple manner.

[0045] By means of the connection unit constructed according to the invention, the region in which the supply line is electrically connected to the connection element of the exhaust system is shielded from environmental influences, in particular from water spray. The risk of electrical short circuits due to water spray can thus be eliminated. Moreover, the risk of excessive corrosion in the region in which the supply line is connected to the exhaust system to the associated connection element is largely eliminated, so that even after a long operating period, the access to the connection region achieved in the connection unit according to the invention makes it possible to electrically or mechanically decouple the supply line from the associated connection element. Due to the sheathing of the region of the electrical connection achieved by the connection unit constructed according to the invention, there is also no risk of accidentally touching the connection element when the heating device is activated during cleaning or maintenance work or of causing a short circuit on one of the connection elements of the heating device or between two connection elements by a tool.

[0046] As an alternative or in addition to providing thermal and electrical insulation by means of the two insulating elements, the connecting unit housing can be at least partially covered on its inner side with an electrically insulating coating, such as a ceramic coating, in order to avoid direct physical contact between the construction material of the connecting unit housing (i.e., for example, sheet material) and the supply line or the connecting element.

[0047] In the connecting unit according to the invention, as an alternative to the essentially rectilinear configuration of the connecting element receiving area or the supply line receiving area shown in the figures, at least one of the two receiving areas is bendable and is therefore constructed to extend along a curved longitudinal axis, so that the curved receiving area also has the two axial end areas described previously.

Claims

1. A connection unit for detachably connecting an electrical supply line (12) to a connection element (14) of an exhaust gas device (16) which is arranged protruding from a heatable exhaust gas device (16), the connection unit comprising a connection unit housing (32) having a connection element receiving region (38) extending in the direction of a first housing axis (G1) and a supply line receiving region (40) extending in the direction of a second housing axis (G2), The connecting element receiving region (38) is open in a first axial connecting element receiving region end region (44) for receiving a connecting element (14) arranged to protrude from the exhaust device (16) and is closed in a second axial connecting element receiving region end region (54) by a cover (56) which is held on the connecting unit housing (32) by a form-fitting structure. The supply line receiving region (40) is open in a first axial supply line receiving region end region (58) towards the connecting element receiving region (38) and is open in a second axial supply line receiving region end region (60) for receiving an electrical supply line (12), A first insulating element (64) is arranged in the connecting element receiving area (38), which first insulating element supports the connecting unit housing (32) relative to the connecting element (14) to be received in the connecting element receiving area (38), The first insulating element (64) has a connecting element receiving opening (70) for receiving a connecting element arranged to protrude from the heatable exhaust gas device (16), so that the connecting element (14) passes through the connecting element receiving opening (70). A second insulating element (72) is arranged in the supply line receiving area (40), which second insulating element supports the connecting unit housing (32) relative to the supply line (12) to be received in the supply line receiving area (40), The second insulating element (72) has a supply line receiving opening (78) for receiving a supply line (12), such that a connection eyelet (28) provided at a connection end (26) of the supply line (12) extends into the connection element receiving region (38), The connecting eyelet (28) is fixed to the connecting element (14) extending through the connecting element receiving opening (70) by means of a threaded mechanism (30) which is threadedly connected to an end (24) of the connecting element (14) provided with an external thread in order to establish an electrically conductive connection at the connecting element (14) and to hold the connecting unit (10) on the connecting element (14), wherein: The conductor element (22) of the connecting element (14) passes through a connecting element receiving opening (70) in a first insulating element (64), the first insulating element (64) is supported axially on the connecting element (14), the connecting eye (28) is pushed onto a section of the conductor element (22) that protrudes beyond the first insulating element (64) and is pressed against the first insulating element (64) via a threaded mechanism (30), whereby the first insulating element (64) is in turn pressed against the connecting element (14) and the connecting unit (10) is thus held in a defined manner relative to the exhaust system (16). The connecting unit housing (32) is constructed with two housing shells (34, 36) connected to each other in a connecting edge area (42), each housing shell (34, 36) having a first housing shell section (34', 36') for providing a connecting element receiving area (38) and a second housing shell section (34", 36") for providing a supply line receiving area (40).

2. The connection unit according to claim 1, characterized in that: The connecting unit housing (32) is at least partially made of sheet metal material.

3. The connection unit according to claim 1 or 2, characterized in that: The connecting unit housing (32) has an exhaust device connecting edge (46) in the first axial connecting element-receiving area-end area (44) that protrudes radially outward relative to the first housing axis (G1), and the exhaust device connecting edge has an exhaust device connecting surface (50) to be positioned that annularly surrounds the first housing axis (G1) and faces a corresponding connecting surface (52) of the exhaust device (16).

4. The connection unit according to claim 3, characterized in that: The exhaust device connection surface (50) is located in a plane orthogonal to the first housing axis (G1).

5. The connection unit according to claim 3, characterized in that: The exhaust device connecting surface (50) is curved.

6. The connection unit according to claim 5, characterized in that: The exhaust device connection surface (50) is bent around a bending axis (K) that is orthogonal to the first housing axis (G1).

7. The connection unit according to claim 1 or 2, characterized in that: The first insulating element (64) is held on the connecting unit housing (32) by a form-fitting structure, and / or the first insulating element (64) is formed of a ceramic material.

8. The connection unit according to claim 1, characterized in that: The second insulating element (72) is held on the connecting unit housing (32) by a form-fitting structure and / or the second insulating element (72) is formed of a ceramic material.

9. The connection unit according to claim 1 or 2, characterized in that: The second shell axis (G2) is orthogonal to the first shell axis (G1).

10. An exhaust device for an internal combustion engine, the exhaust device comprising: An exhaust gas guide component (18); at least one connecting element (14) carried on the exhaust gas guide component (18), the connecting element being used to connect an electrical supply line (12); and a connecting unit (10) according to any one of claims 1 to 9, associated with the at least one connecting element (14), the connecting unit being used to connect an electrical supply line (12) assigned to the at least one connecting element (14) to the connecting element (14).

11. The exhaust device according to claim 10, characterized in that The at least one connecting element (14) is received in a connecting element receiving area (38) of a connecting unit (10) assigned to the connecting element (14), and a supply line (12) assigned to the at least one connecting element (14) is received in a supply line receiving area (40) of a connecting unit (10) assigned to the connecting element (14), so that a connection end (26) of the supply line (12) extends into the connecting element receiving area (38) and is electrically conductively connected to the connecting element (14).

12. The exhaust device according to claim 11, characterized in that A connecting eye (28) on the connecting end (26) of the supply line (12) is pushed onto the connecting element (14) and fixed thereto by means of a screw connection.

13. The exhaust device according to any one of claims 10 to 12, characterized in that: The connecting unit (10) is supported relative to the exhaust system (16) via a first insulating element (64) arranged in the connecting element receiving region (38).

14. The exhaust device according to claim 13, characterized in that The connecting unit (10) is supported relative to the connecting element (14) via a first insulating element (64).

15. The exhaust device according to claim 12, characterized in that The connecting unit (10) is supported relative to the connecting element (14) by a first insulating element (64) arranged in the connecting element receiving area (38), and the first insulating element (64) is held on the exhaust system (16) by means of a threaded mechanism (30) which fixes the supply line (12) on the connecting element (14).

16. The exhaust device according to any one of claims 10 to 12, characterized in that: The curved exhaust system connecting surface (50) is opposite to a curved outer circumferential surface (48) of the exhaust gas conducting component (18) which provides a counter connecting surface (52).

17. The exhaust device according to any one of claims 10 to 12, characterized in that: An exhaust system connection surface (50) lying in a plane orthogonal to the first housing axis (G1) is situated opposite an unbent counter-connection surface (52) on the connection element (14) or on the exhaust gas guide component (18).

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