WO2007098802A1

WO2007098802A1 - Exhaust line system

Info

Publication number: WO2007098802A1
Application number: PCT/EP2006/012610
Authority: WO
Inventors: Martin Geisler; Winfried Willeke
Original assignee: Emcon Technologies Germany (Augsburg) Gmbh
Priority date: 2006-02-24
Filing date: 2006-12-29
Publication date: 2007-09-07
Also published as: DE102006008782A1

Abstract

The invention relates to an exhaust line system, in particular an exhaust manifold, having a wall (34), wherein the wall (34) is a composite component formed from a plurality of film-like layers (38) which are placed one on top of the other and connected to one another.

Description

Abαasleitunqssvstem

The invention relates to an exhaust pipe system, in particular of a vehicle, with a wall.

Internal combustion engine exhaust manifolds typically include piping and fittings such as exhaust manifolds, catalytic converters, or particulate filters. These pipelines or built-in parts have walls that are sometimes exposed to enormous thermal loads. In the case of large local temperature differences, this leads to extreme stress on the wall material and overall to a difficult fastening situation due to the considerable thermal expansion of the pipes or built-in components. A stress-free or low-voltage attachment of the exhaust pipe system is therefore always associated with great effort.

Furthermore, the noise generated in the exhaust pipe system when operating the internal combustion engine is still a problem, although there are already numerous proposals for noise reduction in exhaust pipe systems in the prior art.

The object of the invention is to achieve a better behavior of the exhaust pipe system under thermal stress and a better sound attenuation.

This object is achieved by an inventive exhaust pipe system, wherein the wall of the exhaust pipe system is a composite component of a plurality of superposed, interconnected, film-like layers. Between these individual layers, an oxidation layer forms, which acts as thermal insulation. Furthermore, improved sound attenuation values were found compared to a single-layered wall.

In one embodiment, adjacent film-like layers lie flat against one another. With increasing contact surfaces between the individual Layers increases the mechanical stability of the composite component, so that it can be used in particular as a structural component.

Preferably, adjacent film-like layers are spaced apart in sections, that is, they are not adjacent to each other over the entire surface. Between the junctions of adjacent layers even small spacings are sufficient to achieve an improved sound attenuation of the wall according to the principle of absorption sound attenuation. The layer gaps or micro gaps are usually filled with air and thus also improve the thermal insulation properties of the wall.

The film-like layers are preferably metal foils. Due to the thermal loads, metals with their generally relatively high melting points are particularly suitable as wall material for exhaust pipe systems. In addition, the composite component wall of metal foils can be used well as a supporting component, since metals largely retain their strength even when heated.

For better thermal insulation, it is possible that the exhaust pipe system comprises an air gap insulated exhaust pipe with an inner tube and an outer tube, wherein between the tubes, an air gap is provided.

In this embodiment, the exhaust pipe has a double wall.

Both the inner tube and the outer tube is to be referred to in the sense of this document as a wall, so that the inner and / or outer tube at least partially consists of the interconnected, foil-like layers.

In a particular embodiment is in the air gap between the inner

Pipe and outer tube arranged a non-bearing intermediate plate. This intermediate plate prevents hot Leckesteströmungen, for example, to bumps of the inner tube. The outer tube thus remains selectively spared from thermal extremes. For the purposes of this document, the intermediate sheet is also to be understood as a wall, more precisely as a non-load-bearing wall of the exhaust-gas power system. Accordingly, the intermediate plate at least consist in sections of the interconnected, film-like layers.

Preferably, these film-like layers to form the composite component has a thickness of 0.05 mm to 0.1 mm, which is preferably constant. By means of this relatively thin layer formation, it is also possible to produce non-load-bearing intermediate sheets without too much material consumption from at least two layers. Thus, even with the non-load-bearing walls, at least one oxide insulating layer is formed, which leads to better thermal insulation and better sound-damping behavior of the wall.

The exhaust pipe system may e.g. an exhaust manifold, since the exhaust gas temperatures in the region of the exhaust manifold, i. directly at the cylinder outlets of the engine block, are very high and consequently an improved thermal insulation is particularly advantageous.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. In these show:

- Figure 1 is a schematic longitudinal sectional view through an inventive exhaust pipe system;

FIG. 2 is a sectional view taken along the line H-II in FIG. 1;

- Figure 3 is a sectional view taken along the line III-III in Figure 1;

FIGS. 4a to 4c each show a schematic cross section through an exhaust pipe system according to the invention with enlarged cutouts; and

- Figure 5 shows the detail V of Figure 1 in an alternative embodiment.

In Figure 1, an air gap insulated exhaust manifold is shown, the three cylinder-side inlet pipes 2, 4, 6 connected to each other. The cylinder outlets are symbolized by the circles 8. Each cylinder 8 is assigned its own inlet pipe 2, 4, 6. The inlet pipes 2, 4, 6 have a section 9 coming from the cylinder 8, with which they are welded to the cylinder block flange 11 (FIG. 3), and a cantilevered section with which they continue into a exhaust pipe-side outlet pipe 10 penetrate (Fig. 2 and 3). The exhaust-side outlet pipe 10 is composed of upper and lower shells 12, 14 and has an exhaust-side flange 16 to which an exhaust pipe is attached. On the input side, the outlet pipe 10 is also welded to the cylinder block flange 11. The outlet tube 10 surrounds the inlet tubes 2, 4, 6 in the region in which they flow into one another in terms of flow. The inlet pipes 2, 4, 6 are inserted into one another. The middle inlet tube 4 has for this purpose lateral, enlarged receiving openings facing in opposite directions, while the left and right inlet tube 2, 6 receive slidably. In the interior of the telescoped inlet tubes 2, 4, 6, in the region of the outlet tube 10, a collector chamber 18 is formed, which has a substantially elongated cylindrical shape and in Figure 1 from lying in the plane of the left portion of the left inlet tube 2 to to the right portion of the right inlet tube 6 extends.

Between the inlet pipes 2, 4, 6 and the inside of the outlet pipe 10 is an approximately uniformly thick, the thermal insulation serving air gap 20 is formed.

This air gap 20 is in addition to the thermal insulation and a free expansion of the inlet pipes 2, 4, 6 to the outlet pipe 10 offer, as inlet and outlet pipes attached to each other only at one end and thus are arranged movably inside one another outside the end.

The air gap surrounds the collector chamber 18 on all sides.

Two shell-shaped, deep-drawn intermediate plates with a maximum thickness of 0.3 mm (in the illustrated embodiment just 0.1 mm) are arranged in the air gap 20 and completely surround the collector chamber 18. An upper intermediate plate 22 is inserted into a lower intermediate plate 24, wherein the intermediate plates 22, 24 in the region of Berührränder 26 (Fig. 2) are easily clamped.

The intermediate plates 22, 24 already cover the inlet pipes 2 to 6 immediately after they have penetrated into the outlet pipe 10 (FIG. 3) and, as can be seen in FIG. 1, extend to the flange 16. The intermediate plates 22, 24 complement each other to a very flexible, thin hollow body which is clamped between the inlet pipes 2 to 6 and the outlet pipe 10, without being permanently attached to the pipes and without having a supporting function.

Spacers in the form of generated during deep drawing of the intermediate plates 22, 24 point projections 28 serve the system and the spacing of the intermediate plates 22, 24 on the inlet tubes 2 to 6 and the outlet tube 10, so that the air gap 20 through the intermediate plates into an inner and a outer section 30, 32 is divided. At these projections 28, the intermediate plates 22, 24 at the inlet pipes 2 to 6 or the outlet pipe 10 can be selectively welded.

The intermediate plates 22, 24 are produced by deep drawing a film which, although a uniform thickness, but has a slightly knobbed surface, so that material can flow during deep drawing.

When driving hot exhaust gas flows from the cylinders via the inlet pipes 2 to 6 in the part of the exhaust manifold, in which it is designed clam shell, and enters the collector chamber 18. Due to the slidable mounting of the inlet pipes 2 to 6 to each other there are leakage flows, so that exhaust gas actually hit the inside of the outlet tube 10 at high speed and would lead to hot spots there. Since the intermediate plates 22, 24 but cover almost the entire inside of the air gap 20 outwardly delimiting wall (outlet tube 10), the leakage currents meet the intermediate plates 22, 24. Although it can also come in the region of Berührränder 26 also to leakage flows, this However, in view of the thermal stress of the outlet tube 10 are negligible.

The intermediate sheets are made of temperature resistant material, e.g. AISI 309.

By using the intermediate plates 22, 24, it is also conceivable to use thermally less high-strength materials for the outlet tube 10.

The exhaust manifold according to the figures 1 to 3 is described by way of example as a built-in part of an exhaust pipe system. In this case, the inlet pipes 2 to

6 and the output tube 10 and the thin hollow body in the air gap 20th

Walls 34 in the sense of this document. Examples of such walls 34 At least one of the walls 34 of the exhaust manifold is formed as a composite component of a plurality of superimposed, interconnected, foil-like layers, as described with reference to the examples according to FIGS. 4a to 4c to c can be executed.

Figures 4a to 4c show schematically and by way of example three embodiments of exhaust pipes 36 of an exhaust pipe system with one or more walls 34, wherein at least one wall 34 is a composite component.

FIG. 4 a shows an exhaust gas line 36, in which the exhaust gas flows in

Inside the exhaust pipe 36 is separated only by a single wall 34 from the environment. Accordingly, this wall 34 is formed as a composite component and constructed of several layers 38. The individual layers 38 are shown schematically in the enlarged area of the wall 34 circled by dashed lines. In the present case, each layer 38 consists of a metal foil, preferably a steel foil, but other metals such as aluminum are also suitable.

Figure 4b shows an exhaust pipe 36 with a double wall, i. an inner tube 40 and an outer tube 42. Accordingly, the wall 34 of the inner and / or outer tube may be constructed as a composite member of film-like layers 38. Alternatively, the tubes are wound from a foil.

In Figure 4c, the double-walled exhaust pipe 36 of Figure 4b additionally comprises a non-supporting intermediate plate 44. This structure of the exhaust pipe 36 is in accordance with the structure of the air gap-insulated exhaust manifold according to Figures 1 to 3 functionally identical. The inlet tubes 2 to 6 correspond to the inner tube 40, the outlet tube 10 corresponds to the outer tube 42 and the upper and lower intermediate plate 22, 24 corresponds to the intermediate plate 44. At least one of the illustrated walls 34 (inner tube 40, intermediate plate 44 or outer tube 42nd ) is constructed in this embodiment as a composite component of film-like layers. As can be seen in FIG. 4c, this wall 34 constructed as a composite component is, in particular, the intermediate plate 44 of the exhaust gas line 36. The thickness of the walls 34 is 0.05 mm to 0.1 mm. If a load-bearing wall is to be produced from the films, the thickness can optionally grow up to 0.5 mm.

The circled in Figure 1 dash-dotted section V is shown in an alternative embodiment in Figure 5. In this case, the wall 34 of the

Intermediate plate 44 constructed as a composite component of a plurality of layers 38 and may rest on the inner and / or outer tube 40, 42 or spaced from the inner and / or outer tube 40, 42.

A connecting region 46 between the upper shell 12 and the lower shell 14 of the outer tube 42 is shown in dashed lines in Figure 5. In contrast to the embodiment of Figure 1, the intermediate plate 44 extends in the connecting region 46 between the upper and lower shell 12, 14 to the outside. Thus, in the connection region 46, the individual layers 34 of the intermediate plate 44, the upper and lower shell 12, 14 of the outer tube 42 and the intermediate plate 44 and the outer tube 42 connected in one step, preferably welded together. The intermediate plate 44 is thereby fixed relative to the outer tube 42 in its position so that it can not rattle in the outer tube 42. Alternatively, the film-like layers are spot-welded near the edge of the produced package or at sufficiently spaced points P, e.g. by laser.

In the embodiment with the intermediate plate 44, which consists of film-like layers, the individual walls can also be welded to the projections 28 with each other and simultaneously with the adjacent tube wall.

For all embodiments, in particular:

The layers 38 are shown spaced apart for illustrative purposes, although in reality they abut each other in sections and are joined together by conventional joining methods. Soldering or welding, in particular laser welding, are preferably used joining methods. Between adjacent layers 38, in particular during thermal stress during operation of the exhaust pipe system, small intermediate spaces or micro gaps, which are usually filled with air. In order to avoid a full-surface contact of the layers 38 with each other, the films may have a slightly dimpled surface. This surface is formed during rolling, deep drawing or pressing of the film by means of not completely flat rolling or pressing surface.

Claims

claims

1. exhaust pipe system, in particular of a vehicle, having a wall (34), characterized in that the wall (34) is a composite component of a plurality of superposed, interconnected, film-like layers (38).

2. exhaust pipe system according to claim 1, characterized in that adjacent, film-like layers (38) lie flat against each other.

3. exhaust pipe system according to claim 1 or 2, characterized in that adjacent, foiienartige layers (38) are partially spaced.

4. exhaust pipe system according to one of the preceding claims, characterized in that the film-like layers (38) are metal foils.

5. exhaust pipe system according to one of the preceding claims, characterized by an air gap-insulated exhaust pipe (36) having an inner tube (40) and an outer tube (42), wherein between the tubes (40, 42) an air gap (20) is provided.

6. exhaust pipe system according to claim 5, characterized in that the inner and / or outer tube (40, 42) at least partially from the interconnected, film-like layers (38).

7. exhaust pipe system according to claim 5 or 6, characterized in that in the air gap (20) a non-supporting intermediate plate (44) is arranged.

8. exhaust pipe system according to claim 7, characterized in that the intermediate plate (44) at least partially from the interconnected, film-like layers (38).

9. exhaust pipe system according to one of the preceding claims, characterized in that the film-like layers (38) for forming the

Composite component have a thickness of 0.05 mm to 0.1 mm.

10. exhaust pipe system according to one of the preceding claims, characterized in that the exhaust pipe system is an exhaust manifold.