EP1413719B1 - Exhaust manifold for a combustion engine driven vehicle and an exhaust gas system assembly comprising such an exhaust manifold - Google Patents

Description

The present invention relates to an exhaust manifold for a motor vehicle driven by internal combustion engine, comprising a plurality of individual individual tubes, which are combined on the output side to a tube bundle with adjacent tube wall sections, wherein the output ends of the individual tubes are welded to arranged between the adjacent tube wall sections webs. Furthermore, the present invention relates to such an exhaust manifold and at least one component downstream of this exhaust system.

An exhaust manifold of the type indicated above is known from DE 10051277 A1 known. This exhaust manifold comprises a plurality of individual tubes and an adapter with which the individual tubes are connected on the output side. The adapter, to which in turn the exhaust manifold immediately downstream component of the exhaust system can be connected, consists of an annular wall with a plurality of radially aligned webs, wherein a receptacle is formed by two adjacent webs and a connecting portion of the annular wall , in which one of the individual tubes is inserted with its output-side end. By means of a circumferentially closed fillet weld, the output side end edge of each individual tube is welded in each case to the two adjacent webs and to the corresponding section of the annular wall, for which purpose the webs project beyond the end edges of the individual tubes.

A disadvantage of the DE 10051277 A1 known exhaust manifold is in particular the high production costs associated with the production of the manifold. In this context, in particular the considerable production costs for the adapter play a role. Another disadvantage of the known from this document design of the exhaust manifold is that in the production of said fillet welds inside the individual pipes can adhere spatters and that further a weld elevation can lead to a constriction of the flow cross-section. The welding spatters can not only lead to an impairment of the flow conditions within the individual tubes; rather, they can, which is even more serious, solve in operation and lead to damage to downstream components (eg exhaust gas turbocharger, catalysts). In order to avoid corresponding risks, exhaust manifolds produced accordingly must be subjected to intensive, costly cleaning in order to remove spatters. Finally, the known exhaust manifold is prone to leakage problems, because each of the four individual tubes is to be connected with a closed seam to the adapter, wherein each welding over of the beginning of the seam is required.

Known, eg from the EP 806598 A1 Further, exhaust manifold, in which two individual tubes which have been flattened in the form of D-shaped in the region of their output ends, are inserted back to back abutting each other in a downstream exhaust pipe. In this case, the two individual tubes can be welded together in the region of the connection plane. In exhaust manifolds constructed in this way, various lifetime issues have been observed; In particular, where the individual tubes abut each other, it can lead to stress-induced deformations, as a result of leakage problems occur and / or tear welds.

The EP 0 736 678 A2 shows an exhaust manifold, in which four pipes are flattened in the region of their exhaust-side end to a circle segment quarter. The four quarters are welded together with their flat sides.

In the light of the above-described prior art, the present invention seeks to provide a durable, reliable exhaust manifold of the type described, which can be produced with a comparatively low production cost and at a correspondingly low cost.

• die Stege sind gegenüber den ausgangsseitigen Stirnkanten der Einzelrohre zurückgezogen;
• jeweils zwei Einzelrohre sind stirnseitig mittels einer den zwischen ihnen angeordneten Steg erfassenden Nutschweißung miteinander verbunden.

This object is achieved according to the present invention by a generic exhaust manifold, which is characterized by the following features:

• the webs are withdrawn relative to the output side end edges of the individual tubes;
• in each case two individual tubes are connected to one another at the front side by means of a slot weld which detects the web arranged between them.

By projecting the individual tubes with their outlet-side ends over the webs, two individual tubes in the region of their adjacent tube wall sections can be connected to one another with a single weld seam as well as to the web arranged between the respective tube wall sections. In this way, the number of welds over that from the DE 10051277 A1 halve known exhaust manifold. In addition, the present invention makes it possible to perform the respective welds as grooved welds; In this way, the risk that spatter inside reach the individual tubes, significantly reduced compared with that of the DE 10051277 A1 known construction. If necessary, which is not possible in the known generic exhaust manifold, in the case of the present invention, the outlet-side ends of the individual tubes during the production of the exhaust manifold even be closed, whereby a penetration of weld spatter into the individual tubes is definitely excluded. In terms of manufacturing costs is particularly attractive that the webs can be designed as a simple sheet metal parts, with identical web material, as will be explained in detail below, even for different exhaust manifolds can be used; this too is a significant advantage over the prior art which requires different adapters for different exhaust manifolds.

Both with regard to the manufacturing costs as well as with regard to the life of the exhaust system produced using the exhaust manifold according to the invention, it is advantageous if, according to a particularly preferred embodiment of the invention, the exhaust manifold immediately downstream component of the exhaust system directly to the individual pipes, on which the said component is plugged connected. So does the omission of the adapter of the exhaust manifold after the DE 10051277 A1 provided annular wall immediately in reduced material costs. Furthermore, in this case, in the sense of a particularly favorable distribution of the masses in the region of the transition from the exhaust manifold to the immediately downstream component of the exhaust system that the life negatively affecting thermal stresses are largely avoided; In this respect, particularly favorable conditions are present in average-sized exhaust manifolds when the thickness of the webs between 1.5 times and 3.5 times the value of the wall thickness of the individual tubes is. Furthermore, in this development of the exhaust manifold according to the invention advantageous that, unlike that for the connection of the individual tubes with the adapter in the case of the exhaust manifold after the DE 10051277 A1 applies, is not often associated with leaks problems welding over of seam starts is required.

As regards the design of the webs, a preferred development of the invention is characterized in that the Webs are designed as independent single webs, which are not connected to each other before mounting the exhaust manifold. Identical individual webs, which particularly preferably consist of sheets bent along one edge, can be used for different exhaust manifolds, for example for exhaust manifolds of the 3-in-1 construction, the 4-in-1 construction and the 5-in-1 Design type. This advantage clearly contributes to the possibility of significant cost savings.

With regard to a simplified assembly of the exhaust manifold according to the invention, the webs, if they are designed in the sense set out above as individual webs, particularly preferably with one of their associated individual tubes are connected before they are joined together to form a tube bundle. For the connection of the individual webs with the individual tubes, in particular, welding methods known as such (tack welding) and adhesive methods are suitable.

In the context of the present invention, however, it is by no means mandatory that the webs are designed as single webs in the sense set out above. Rather, the webs may be part of a uniform star-shaped web component. The web component may in particular consist of a multiply folded, sheet metal strip, wherein each web has at least two layers of the sheet metal strip. The effort associated with folding the sheet metal strip into a unitary web component comprising a plurality of webs is optionally more than offset by cost savings resulting from the use of a relatively thin-walled, relatively inexpensive sheet material for producing the web component.

With regard to the manufacturing costs as well as on the life of the exhaust manifold according to the invention it proves It is particularly advantageous if in each case a weld along two webs is carried out continuously. In this sense, for example, in an exhaust manifold of the 4-in-1 construction, the four individual tubes may be connected to each other by two respective L-shaped welds and with the four arranged between the individual tubes webs, as will be explained in more detail below.

It is only for the sake of completeness that it should be pointed out that the realization of the present invention is not limited to single-walled single-walled pipes. On the contrary, in accordance with the present invention, it is also possible to produce exhaust manifolds whose individual tubes are double-walled (with or without air-gap insulation).

It should also be noted that the present invention does not require that all individual tubes in the region of their respective outlet-side end coincidentally have a circular segment-shaped cross-section; Rather, for example, an embodiment of the exhaust manifold according to the invention in such a way that in the region of the outlet end a plurality of individual tubes are grouped around a centrally arranged single tube.

Fig. 1

in perspektivischer Ansicht ein Einzelrohr, das in Verbindung mit drei weiteren gleichartigen Einzelrohren zur Herstellung eines nach der vorliegenden Erfindung aufgebauten Abgaskrümmers der 4-in-1-Bauweise dient,

Fig. 2

in perspektivischer Ansicht die Austrittsseite eines unter Verwendung von vier Einzelrohren der in Fig. 1 veranschaulichten Art hergestellten Abgaskrümmers und

Fig. 3

einen Schnitt durch den Abgaskrümmer nach Fig. 2 entlang der Linie III-III.

In the following, the present invention will be explained in more detail with reference to an embodiment illustrated in the drawing. It shows

Fig. 1

a perspective view of a single tube, which is used in conjunction with three other similar single tubes for producing a constructed according to the present invention exhaust manifold of the 4-in-1 construction,

Fig. 2

in a perspective view of the exit side of a using four individual tubes of in Fig. 1 Illustrated type manufactured exhaust manifold and

Fig. 3

a section through the exhaust manifold after Fig. 2 along the line III-III.

This in Fig. 1 shown single tube 1 has an inlet-side end 2 and an outlet-side end 3. It is, depending on the structural conditions, ie the installation conditions of the exhaust system relative to the associated internal combustion engine, repeatedly bent between its inlet-side end 2 and its outlet-side end 3.

In the region of its outlet-side end 3, the single tube 1, which otherwise has a substantially round cross-section, reshaped in such a way that it has a cross section substantially corresponding to a quarter-circle segment. For this purpose, two substantially planar pipe wall sections 4 and 5 arranged at a right angle to each other and an outer pipe wall section 6 curved substantially along a quarter circle are provided.

At one of the two planar pipe wall regions, namely the pipe wall section 5, a web 8 designed as a single web 7 is attached by means of a resistance spot weld 9. In the region of the corner 10 where the two levels of pipe wall cuts 4 and 5 meet, the single web has a turn 11 on, whose function and dimensioning out Fig. 2 results.

To produce the exhaust manifold 12 four of the individual tubes 1, as they are in kind in Fig. 1 illustrates are, assembled in such a way that in each case between two adjacent individual tubes in the region of the adjacent planar tube wall sections is a single web 7. By means of two welds 13, which in each case as a two individual tubes 1 and the individual web 7 arranged therebetween groove weld 14 (see. Fig. 3 ), the four individual tubes 1 are connected to one another in the region of their outlet-side ends 3. The two welds 13 pull without interruption L-shaped along the flat tube wall sections of two diametrically opposed individual tubes along; In other words, each weld 13 extends without interruption along two adjacent webs 8. The welds begin and end at the respective radial outer edge 15 of the webs 8.

In order to produce an assembly of an exhaust system comprising the exhaust manifold and a downstream component, the downstream component (exhaust pipe, catalyst or the like), not shown, is pushed with a tubular section over the exit end 16 of the exhaust manifold 12; and the component is welded via a corresponding circumferential weld directly with the combined there to form a tube bundle individual tubes.

Claims (9)

1. An exhaust manifold (12) for a motor vehicle driven by an internal combustion engine, comprising a plurality of single, individual pipes (1) which are brought together on the output side to form a bundle of pipes having pipe wall sections (4, 5) adjacent to each other, the ends (3) on the output side of the individual pipes (1) being welded to webs (8) arranged between the pipe wall sections (4, 5) adjacent to each other, characterized in that

   - the webs (8) are made retracted in relation to the front edges on the output side of the individual pipes (1), and

   - the individual pipes (1) are each connected to the other on the front end by means of a groove welding (14) covering the web (8) arranged between them.
2. The exhaust manifold according to claim 1,
   characterized in that
   the webs (8) are configured as individual webs (7).
3. The exhaust manifold according to claim 1 or claim 2,
   characterized in that
   the individual webs (7) consist of metal sheets which each have a bent portion (11) along an edge.
4. The exhaust manifold according to claim 2 or claim 3,
   characterized in that
   the individual webs (7) were each connected with a respective one of the individual pipes (1) associated with them before the latter were joined to form a bundles of pipes.
5. The exhaust manifold according to claim 1,
   characterized in that
   the webs (8) are part of a unitary web component.
6. The exhaust manifold according to claim 5,
   characterized in that
   the web component consists of a folded sheet metal strip, each web including at least two layers of the sheet metal strip.
7. The exhaust manifold according to any of claims 1 to 6,
   characterized in that
   the thickness of the webs (8) amounts to between 1.5 times and 3.5 times the wall thickness of the individual pipes (1).
8. The exhaust manifold according to any of claims 1 to 7,
   characterized in that
   respective weld seams (13) are each formed to be continuous along two webs (8).
9. An assembly of an exhaust system for a motor vehicle driven by an internal combustion engine, comprising an exhaust manifold (12) according to any of the preceding claims and at least one component connected downstream thereof (pipe, muffler, filter, catalytic converter or the like),
   wherein the component of the exhaust system that is connected immediately downstream of the exhaust manifold is directly connected with the individual pipes (1) onto which the said component is fitted.

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