EXHAUST GAS SYSTEM COMPONENT FOR AN EXHAUST SYSTEM OF AN INTERNAL COMBUSTION ENGINE

Description

[0001] The present invention relates to an exhaust gas routing component for an exhaust system of an internal combustion engine.

[0002] To prevent heat loss from the exhaust gas passing through exhaust systems for internal combustion engines, it is known to use double-walled exhaust duct components. Insulating material, for example, foamed or fiber-based, providing thermal insulation, can be arranged in a space formed between a generally tubular outer body and a generally tubular inner body. The formation of an air cushion between an inner body and an outer body can also contribute to thermal insulation.

[0003] To create a strong bond, the outer body and the inner body are firmly connected to one another in the fastening area at the two end regions of a component body constructed with them, for example, by material bonding. Since the outer body and the inner body are heated to different degrees by the exhaust gas, which essentially only comes into direct contact with the inner body, they are subject to different thermally induced dimensional changes, which can lead to severe thermomechanical stress on the outer body or the inner body, or on the fastening areas formed in the two end regions, particularly between the two end regions.

[0004] An exhaust gas routing component according to the preamble of claim 1 is known from GB 1 367 181 A. In this exhaust gas routing component, a tubular inner body is accommodated in a tubular outer body to provide a tubular component body with component body end regions spaced apart from one another in the direction of a component body longitudinal axis. The tubular inner body is constructed with a plurality of segments arranged successively in the direction of the component body longitudinal axis. In the component body end regions, respective inner body end sections of segments of the inner body provided in association with the component body end regions are accommodated in outer body end sections of the outer body and are thus connected in a fluid-tight manner by welding.In those areas where the segments of the inner body adjoin one another, they overlap in the direction of the component body's longitudinal axis, so that the segments of the inner body can move relative to one another and relative to the outer body.

[0005] It is the object of the present invention to provide an exhaust gas routing component for an exhaust system of an internal combustion engine which avoids the occurrence of thermally induced loads while providing good thermal insulation.

[0006] According to the invention, this object is achieved by an exhaust gas guide component for an exhaust system of an internal combustion engine according to claim 1. This exhaust gas guide component comprises a tubular component body with a first component body end region and a second component body end region arranged at a distance from the first component body end region in the direction of a component body longitudinal axis, wherein the component body comprises a tubular outer body and a tubular inner body received in the tubular outer body, wherein the inner body is fixed to the outer body in a fastening region, and wherein a sliding guide is provided which acts between the outer body and the inner body and allows a relative movement of the inner body with respect to the outer body outside the fastening region.

[0007] In an exhaust gas guide component constructed according to the invention, a defined positioning of these two bodies relative to one another is generally ensured by providing a fastening region in which the outer body and the inner body are secured to one another. In regions outside of this fastening region, the outer body and the inner body can generally move relative to one another, whereby the sliding guide and the guiding effect of the inner body relative to the outer body provided thereby prevent undefined relative movements between the inner body and the outer body caused by thermally induced loads or mechanical loads, such as vibrations.

[0008] In order to provide a defined flow volume for the exhaust gas in the exhaust gas guide component, which flow volume is essentially provided by the inner body, the outer body has a preferably essentially cylindrical first outer body end section in the first component body end region and the inner body has a preferably essentially cylindrical first inner body end section received in the first outer body end section and in the second component body end region the outer body has a preferably essentially cylindrical second outer body end section and the inner body has a preferably essentially cylindrical second inner body end section received in the second outer body end section.

[0009] The fastening region is provided at the first component body end region or the second component body end region. Since such a fastening region is formed in only one of the component body end regions, the inner body and the outer body can move relative to each other in a defined manner in all other regions, in particular also in the other component body end region, guided by the sliding guide.

[0010] For example, the first inner body end portion may be fixed to the first outer body end portion or the second inner body end portion may be fixed to the second outer body end portion.

[0011] A fastening that is resistant to thermal influences and chemicals is achieved by securing the inner body to the outer body in the fastening area by means of material closure and / or press fitting.

[0012] To provide a defined guiding effect, the sliding guide comprises on the outer body two guide recesses which are essentially diametrically opposed to one another with respect to the component body longitudinal axis, extend essentially in the direction of the component body longitudinal axis and are open essentially radially inward in the direction of an outer body interior with respect to the component body longitudinal axis, and on the inner body, in association with each guide recess, at least one guide projection which extends essentially in the direction of the component body longitudinal axis and engages essentially radially outward in the associated guide recess with respect to the component body longitudinal axis.

[0013] In order to be able to accommodate dimensional changes in the longitudinal direction, but also transversely to the longitudinal direction, it is proposed that at least one, preferably each guide projection is accommodated in the associated guide recess so as to be displaceable essentially in the direction of the component body longitudinal axis and / or essentially transversely to the component body longitudinal axis.

[0014] In a structurally simple embodiment, at least one, preferably each guide recess can be formed in an outer body shell adjoining region of two outer body shells.

[0015] For this purpose, for example, in the outer body shell adjoining region, each of the outer body shells can comprise an outer body connection / guide edge extending in the direction of the component body longitudinal axis along an outer body shell shell body and from the outer body shell shell body with respect to the component body longitudinal axis substantially radially outward, with an outer body guide edge section adjoining the outer body shell shell body and an outer body connection edge section adjoining the outer body guide edge section on a side of the outer body guide edge section facing away from the outer body shell shell body, and in the outer body shell adjoining region, the outer body connection edge sections of the outer body shells can be firmly connected to one another, and the guide recess can be formed between the outer body guide edge sections of the outer body shells.

[0016] The exhaust gas guide component can be constructed with a small number of components if the outer body comprises two, e.g. exactly two, outer body shells and a first guide recess is formed in a first outer body shell adjoining region of the two outer body shells and a second guide recess is formed in a second outer body shell adjoining region of the two outer body shells.

[0017] For a defined guiding effect of the sliding guide, it can further be provided that at least one, preferably each guide recess is designed to be continuous without interruption in the direction of the component body longitudinal axis.

[0018] Also in the area of ​​the inner body, at least one, preferably each guide projection can be formed in an inner body shell adjoining area of ​​two inner body shells to one another for a structure that is easy to implement.

[0019] For this purpose, in the inner body shell abutment region, each of the inner body shells can comprise an inner body connection / guide edge extending in the direction of the component body longitudinal axis along an inner body shell shell body and from the inner body shell shell body with respect to the component body longitudinal axis substantially radially outward, and in the inner body shell abutment region, the inner body connection / guide edges of the inner body shells can be firmly connected to one another and form the guide projection.

[0020] For a structure requiring few components also in the area of ​​the inner body, it is proposed that the inner body comprises two, e.g. exactly two, inner body shells, and that a first guide projection is formed in a first inner body shell adjoining area of ​​the two inner body shells and a second guide projection is formed in a second inner body shell adjoining area of ​​the two inner body shells.

[0021] Insulating material can be arranged in a space formed between the outer body and the inner body to obtain improved thermal insulation.

[0022] The invention further relates to an exhaust system comprising at least one exhaust gas routing component constructed according to the invention.

[0023] The present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 a partial longitudinal sectional view of an exhaust system with a tubular exhaust gas guide component; Fig. 2 a perspective cross-sectional view of the Fig. 1 shown exhaust gas routing component, sectioned along a line II-II in Fig. 1 .

[0024] In Fig. 1 A partial region of an exhaust system, generally designated 10, for an internal combustion engine, for example a vehicle, is shown in longitudinal section. The exhaust system 10 comprises an exhaust gas guide component 12 through which exhaust gas flows during operation of an internal combustion engine, said exhaust gas guide component comprising a tubular component body 14. The component body 14 has an upstream first component body end region 16, in which it adjoins a further, for example tubular, exhaust gas guide component 18. The component body 14 further has a downstream second component body end region 20, in which it likewise adjoins a further, for example tubular, exhaust gas guide component 22.

[0025] The component body 14 is double-walled and comprises a tubular outer body 24 and an equally tubular inner body 26 received in the tubular outer body 24. To enable a stable and gas-tight connection of the component body 14 in the first component body end region 16 to the further exhaust gas guide component 18, the outer body 18 is formed in the first component body end region 16 with a substantially cylindrical first outer body end section 28. Likewise, the inner body 26 is formed in the first component body end region 16 with a substantially cylindrical first inner body end section 30, which is received in the first outer body end section 28 and ends flush with the latter, for example in the direction of a component body longitudinal axis L.In the region of the first outer body end section 28, the outer body 24 can be firmly connected to the inner body 26 in the region of its first inner body end section 30, for example by material bonding, such as welding, and / or by press fitting.

[0026] The component body longitudinal axis L can be a longitudinal center axis of the component body 14, which extends along the course of the component body 14, which may also be curved in some regions, for example, and can essentially define the cross-sectional center of the component body 14 in each length region, for example.

[0027] In the second component body end region 20, the outer body 24 has a substantially cylindrically shaped second outer body end portion 32. Accordingly, the inner body 26 also has a substantially cylindrically shaped second inner body end portion 34 in the second component body end region 20, which is received in the second outer body end portion 32 with a tight fit but is not fixed thereto.

[0028] In Fig. 1 It can be seen that in order to adapt to the further exhaust gas guide component 22 adjoining the exhaust gas guide component 14 in the second component body end region 20, the component body 14 can have a radial extension with respect to the component body longitudinal axis L in the transition to the second component body end region 20 or to the second outer body end section 32 and to the second inner body end section 34.

[0029] In an intermediate space 36 formed between the outer body 24 and the inner body 26, insulating material 38 can be arranged at least in some areas, which, in addition to the radial spacing of the outer body 24 from the inner body 26, ensures good thermal insulation between them.

[0030] On the outer body 24, for example, in the region of respective radially inwardly directed indentations 40, 42, a nozzle 44, for example, for receiving a temperature sensor or the like, and a nozzle 46 for receiving an injector injecting a reactant into the exhaust gas stream or another sensor can be provided. In the region of the indentations 40, 42 of the outer body 24, the inner body 26 can also have corresponding indentations 48, 50 with respective openings through which the nozzles 44, 46 are open to the volume 51 formed in the inner body 26 and through which exhaust gas can flow. It should be noted that even in the region of the mutually associated indentations 40, 48 and 42, 50, the outer body 24 is fundamentally not firmly connected to the inner body 26.

[0031] For stable mounting of the exhaust system 10 on a vehicle, one or more support struts 52 can be provided on the component body 14 or on the outer body 24 thereof, which can provide support for the exhaust system 10, for example with respect to the underbody of a vehicle, via bearing sleeves 54 constructed, for example, with rubber material, which also ensures vibration decoupling.

[0032] As particularly in Fig. 2 As can be seen, the outer body 24 is constructed with two outer body shells 56, 58, which are formed, for example, as formed sheet metal parts. The connecting pieces 44, 46, for example, can be provided on the outer body shell 56, and the support strut(s) 52 can be fixed to the outer body shell 58.

[0033] The two outer body shells 56, 58 adjoin one another in outer body shell abutment regions 60, 62 extending substantially in the direction of the component body longitudinal axis L. In each of the outer body shell abutment regions 60, 62, each outer body shell 56, 58 has an outer body connection / guide edge 68, 70 extending radially outward along a respective outer body shell shell body 64, 66 substantially in the direction of the component body longitudinal axis L and with respect thereto. Each outer body connection / guide edge 68, 70 comprises an outer body guide edge portion 72 adjacent to the respective outer body shell body 64, 66 and an outer body connection edge portion 74 adjacent to the respective outer body guide edge portion 72 on its side facing away from the respective outer body shell body 64, 66.

[0034] In the area of ​​the outer body connection edge sections 74 of the outer body connection / guide edges 68, 70 formed in the two outer body shell adjoining regions 60, 62, the outer body shells 56, 58 abut one another and are firmly and gas-tightly connected to one another, for example by welding. When the outer body connection edge sections 74 abut one another, the outer body guide edge sections 72 of the mutually associated outer body connection / guide edges 62, 70 are spaced apart from one another, so that a guide recess 76 is formed between them, which is open radially inward to an outer body interior space also containing the inner body 26 and extends along the outer body 24, preferably without interruption, between the component body end regions 16, 20.

[0035] In order to enable connection of the component body 14 to the other exhaust gas routing components 18, 22 in the component body end regions 16, 20, the outer body 24 or the two outer body shells 56, 58 in the outer body end sections 28, 32 are not formed with the radially outwardly projecting outer body connection / guide edges 68, 70. These edges already end before the outer body end sections 28, 32, so that they can be formed on their outer circumference, for example, with a circular circumferential contour.

[0036] The inner body 26 is constructed in correspondence with the outer body 24 with two inner body shells 78, 80, which are formed, for example, as formed sheet metal parts. These adjoin one another in inner body shell abutment regions 82, 84 extending in the direction of the component body's longitudinal axis L, wherein each inner body shell abutment region 82, 84 is assigned to and opposite one of the outer body shell abutment regions 60, 62.

[0037] In each of the inner body shell abutment regions 82, 84, the inner body shells 78, 80 have inner body connection / guide edges 90, 92 extending radially outward from a respective inner body shell body 86, 88 and substantially in the direction of the component body's longitudinal axis L. In the region of the paired inner body connection / guide edges 90, 92, the two inner body shells 78, 80 are firmly and gas-tightly connected to one another, for example by welding. Each pair of firmly connected inner body connection / guide edges 90, 92 forms a guide projection 94 extending radially outward relative to the component body's longitudinal axis L and extending substantially uninterruptedly in the direction thereof.Each of the guide projections 94 thus formed engages radially outwardly into one of the guide recesses 76 formed in the outer body shell abutment regions 60, 62, so that a sliding guide 96 for the inner body 26 with respect to the outer body 24 is formed by the two guide projections 94 each engaging in a guide recess 76.

[0038] In order to also provide an outer circumferential contour on the inner body 24 at the two inner body end sections 30, 34, for example, which is essentially circular and not influenced by the radially outwardly extending guide projections 94, the inner body connection / guide edges 90, 92, which basically extend essentially over the entire length of the inner body 26, end shortly before the inner body end sections 30, 34. In the inner body end sections 30, 34, no radially outwardly extending guide projections 94 are therefore provided, which could impair the adaptation of the inner body end sections 30, 34 into the outer body end sections 28, 32.

[0039] As already explained, in the region of the first component body end region 16, the outer body 24 and the inner body 26 can be firmly connected with their first outer body end section 28 and first inner body end section 30, for example by material bonding, e.g. welding, so that a fastening region 98 is formed at the first component body end region 16, in which fastening region a firm connection is formed between the outer body 24 and the inner body 26, so that in this fastening region 98 a relative movement between the outer body 24 and the inner body 26 cannot occur. In all length regions lying outside the fastening region 98, the outer body 24 and the inner body 26 are not firmly connected to one another, so that in all length regions lying outside the fastening region 98, the inner body 26 can move in a defined manner relative to the outer body 24 under the guiding effect of the sliding guide 96.In particular, due to the sliding guide 96 running essentially in the direction of the component body's longitudinal axis L, the inner body 26 can move in the direction of the component body's longitudinal axis L relative to the outer body 24. Furthermore, the inner body 26 can move radially relative to the outer body 24 under the guiding effect of the sliding guide 96. Such axial or radial relative movement between the inner body 26 and the outer body 24 can occur in particular when, as comparatively hot exhaust gas flows through it, the inner body 26 is heated to a greater extent and will therefore have a higher temperature than the outer body 24. A higher temperature of the inner body 26 leads to a greater thermally induced expansion of the same in both the axial and radial directions.With such different thermally induced dimensional changes, the guide projections 94 can move in the guide recesses 76 that respectively accommodate them in the direction of the component body's longitudinal axis L and can penetrate into it more radially outwards. Since a fixed point exists only in the single fastening region 98 at the first component body end region 16, and such relative movement between the inner body 26 and the outer body 24 can occur in all other longitudinal regions, no tensions arise between the inner body 26 and the outer body 24, which could lead in particular to excessive loading in the fastening region 98. Furthermore, by means of the sliding guide 96, a bearing is provided that allows a relative movement of the inner body 26 with respect to the outer body 24, which enables a defined movement between the inner shell 26 and the outer shell 24, for example when excited by oscillations or vibrations.This bearing effect or defined guidance of the inner body 26 with respect to the outer body 24 can be further supported by the insulating material 38, which is provided, for example, with wire material, such as wire mesh or nonwoven material, and which is positioned between the inner body 26 and the outer body 24.

[0040] In the construction illustrated in the figures, the inner body 26, which is basically constructed with the two inner body shells 78, 80, can be divided into two parts 100, 102 adjoining one another in the direction of the component body's longitudinal axis L. The previously mentioned change in the radial dimension of the inner body 26 in the transition to the second inner body end section 34 is provided, in particular, in part 100. Each of these parts 100, 102 of the inner body 26 can be provided by a correspondingly shaped section of the two inner shells 78, 80, so that each inner shell 78, 80 can also be composed of two parts.

Claims

1. An exhaust gas routing component for an exhaust gas system of an internal combustion engine, comprising a tube-like component body (14) with a first component body end region (16) and a second component body end region (20) arranged in the direction of a component body longitudinal axis (L) at a distance from the first component body end region (16), wherein the component body (14) comprises a tube-like outer body (24) and a tube-like inner body (26) received in the tube-like outer body (24), wherein the inner body (26) is fixed in a fastening region (98) to the outer body, wherein, in the fastening region (98), the inner body (26) is fixed on the outer body (24) by material connection and / or interference fit and wherein there is provided a sliding guide (96) which acts between the outer body and the inner body (26) and permits a relative movement of the inner body (24) in relation to the outer body (24) outside the fastening region (98), wherein, in the first component body end region (16), the outer body (24) has a first outer body end portion (28) and the inner body (26) has a first inner body end portion (30) which is received in the first outer body end portion (28) and in the second component body end region (20), the outer body (24) has a second outer body end portion (32) and the inner body (26) has a second inner body end portion (34) which is received in the second outer body end portion (32), characterized in that the fastening region (98) is provided on the first component body end region (16) or the second component body end region (20), and in that the sliding guide (96) comprises, on the outer body (24), two guide recesses (76) which are substantially diametrically opposed and extend substantially in the direction of the component body longitudinal axis (L) and are open in relation to the component body longitudinal axis (L) substantially radially inwards in the direction of an outer body inner space, and comprises at the inner body (26) in association to each guide recess (76) at least one guide projection (94) which extends substantially in the direction of the component body longitudinal axis (L) and engages in relation to the component body longitudinal axis (L) substantially radially outward into the assigned guide recess (76).

2. The exhaust gas routing component as claimed in claim 1, characterized in that, in the first component body end region (16), the outer body (24) has a first outer body end portion (28) which is substantially cylindrical and the inner body (26) has a first inner body end portion (30) which is received in the first outer body end portion (28) and is substantially cylindrical, and in that in the second component body end region (20), the outer body (24) has a second outer body end portion (32) which is substantially cylindrical and the inner body (26) has a second inner body end portion (34) which is received in the second outer body end portion (32) and is substantially cylindrical.

3. The exhaust gas routing component as claimed in claim 1 or 2, characterized in that the first inner body end portion (30) is fixed on the first outer body end portion (28), or in that the second inner body end portion (34) is fixed on the second outer body end portion (32).

4. The exhaust gas routing component as claimed in any one of claims 1-3, characterized in that at least one, preferably each guide projection (94) is received displaceably in the assigned guide recess (76) substantially in the direction of the component body longitudinal axis (L) and / or substantially transversely to the component body longitudinal axis (L).

5. The exhaust gas routing component as claimed in any one of claims 1-4, characterized in that at least one, preferably each guide recess (76) is formed in an outer body shell-adjoining region (60, 62) of two outer body shells (56, 58) against one another.

6. The exhaust gas routing component as claimed in claim 5, characterized in that in the outer body shell-adjoining region (60, 62), each of the outer body shells (56, 58) comprises an outer body connection / guide edge (68, 70) which extends substantially radially outward in the direction of the component body longitudinal axis (L) along an outer body shell-shell body (64, 66) and from the outer body shell-shell body (64, 66) in relation to the component body longitudinal axis (L) with an outer body guide edge portion (72) which adjoins the outer body shell-shell body (64, 66) and an outer body connection edge portion (74) which adjoins the outer body guide edge portion (72) at a side of the outer body guide edge portion (72) facing away from the outer body shell-shell body (64, 66), and, in the outer body shell-adjoining region (60, 62), the outer body connection edge portions (74) of the outer body shells (64, 66) are fixedly connected to one another and the guide recess (76) is formed between the outer body guide edge portions (72) of the outer body shells (64, 66).

7. The exhaust gas routing component as claimed in claim 5 or 6, characterized in that the outer body (24) comprises two outer body shells (56, 58), and in that a first of the guide recesses (76) is formed in a first of the outer body shell-adjoining regions (68, 62) of the two outer body shells (56, 58) and a second of the guide recesses (76) is formed in a second of the outer body-shell adjoining regions (60, 62) of the two outer body shells (56, 58).

8. The exhaust gas routing component as claimed in any one of claims 1-7, characterized in that at least one, preferably each guide recess (76) is formed to be continuously free of interruptions in the direction of the component body longitudinal axis (L).

9. The exhaust gas routing component as claimed in any one of claims 1-8, characterized in that at least one, preferably each guide projection (94) is formed in an inner body shell-adjoining region (82, 84) of two inner body shells (78, 80) against one another.

10. The exhaust gas routing component as claimed in claim 9, characterized in that in the inner body shell-adjoining region (82, 84), each of the inner body shells (78, 80) comprises an inner body connection / guide edge (90, 92) extending in the direction of the component body longitudinal axis (L) along an inner body shell-shell body (86, 88) and substantially radially outward from the inner body shell-shell body (86, 88) in relation to the component body longitudinal axis (L), and, in the inner body shell-adjoining region (82, 84), the inner body connection / guide edges (90, 92) of the inner body shells (78, 80) are fixedly connected to one another and form the guide projection (94).

11. The exhaust gas routing component as claimed in claim 9 or 10, characterized in that the inner body (26) comprises two inner body shells (78, 80), and a first of the guide projections (94) is formed in a first of the inner body shell-adjoining regions (82, 84) of the two inner body shells (78, 80) and a second of the guide projections (94) is formed in a second of the inner body shell-adjoining regions (82, 84) of the two inner body shells (78, 80).

12. The exhaust gas routing component as claimed in any one of claims 1-11, characterized in that insulating material (38) is arranged in a gap (36) formed between the outer body (24) and the inner body (26).

13. An exhaust gas system, comprising at least one exhaust gas routing component (12) as claimed in any one of claims 1-12.