EP1388651B1 - Exhaust gas apparatus for a vehicle's internal combustion engine - Google Patents

Description

The invention relates to an exhaust system for the internal combustion engine of a motor vehicle, comprising a pipe string with at least one silencer, according to the preamble of claim 1.

Such an exhaust system is eg off US 5,941,070 A or DE 41 04 906 A known.

The invention is based on the technical problem of designing the exhaust system in such a way that the exhaust system can be fastened at certain distances, preferably in the region of the muffler, at a small distance to the motor vehicle and still the thermal expansions of the exhaust system can be accommodated.

This technical problem is solved by an exhaust system according to claim 1.

By virtue of the invention, the exhaust system can be fastened to the motor vehicle relatively unyieldingly in an area, preferably in its rear area. The thermal expansions occurring between the front end of the exhaust system and this fastening area can be absorbed by the displaceable telescopic seat. In the field of relatively unyielding attachment, the distance space to the motor vehicle can be kept small, so that space for other functions is obtained.

The exhaust system according to the invention is particularly intended for passenger cars. Particularly suitable locations for the positioning of the telescopic seat are those on which the exhaust system extends substantially in the longitudinal direction of the motor vehicle or the exhaust system. Technically simplest is feasible if the telescopic seat between a tubular first area of the exhaust system or a first pipe section and a tubular second portion of the exhaust system or a second pipe section is provided, very particularly favorable a point at which anyway a pipe line connection (welded joint or screw) was provided. Alternatively, the telescopic seat can for example be provided at the transition between a silencer or a catalyst body housing and the actual pipe string. In itself, you can provide the telescopic seat at any point along the length of the exhaust system. However, the region is particularly favorable approximately in the middle region of the length of the exhaust system, for example between a catalyst body housing and a middle silencer, or an area farther back in the exhaust system, eg a piece in front of the rear silencer.

According to the invention, the ring, which has predominantly sealing function, has a diameter increasing over its length. One can make this diameter increase alone on the outer diameter, but particularly favorable is diameter increase both the outer diameter and the inner diameter. A good way is to make the diameter increase conical. Sealing-function rings designed in accordance with the measures mentioned in this paragraph have a particularly secure sealing function, also in view of manufacturing tolerances of the outer component and the inner component of the telescopic seat and also in view of different thermal expansions. The above description of the ring, which has mainly sealing function, refers to the state the assembly of the telescope seat. After assembly of the telescopic seat, this ring is usually somewhat deformed in contrast; As a rule, however, even then the diameter increase is present.

Preferably, at least one of the rings is a metal knit ring, most preferably all rings are metal knit rings. Metallic knitted rings are available in a variety of embodiments on the market. Metal knit rings are characterized by the fact that they are able to cope with the temperatures occurring at exhaust systems easily. For rings which have a predominantly sealing function, those embodiments which are particularly designed for gas tightness from the wire cross section and / or from the knitted design and / or from the type of pressing of the wire mesh are particularly suitable.

Preferably, the at least one metal knit ring is a pressed metal knit ring, particularly preferably all metal knit rings are pressed metal knit rings.

Preferably, the telescopic seat on the inside or outside on two axially spaced, circumferential beads, between which at least one ring is axially fixed. In this simple manner, the at least one ring is fixed to the outer or the inner component of the telescopic seat against movements in the axial direction. Upon displacements of the telescopic seat, the at least one ring slides along the other telescopic seat component.

Metallic knitted rings for the exhaust system according to the invention are available on the market.

• Fig. 1 eine schematisierte Abgasanlage für den Verbrennungsmotor eines Kraftfahrzeugs mit Frontmotor, in Draufsicht bei einbaugemäßer Positionierung;
• Fig. 2 in größerem Maßstab einen Teleskopsitz der Abgasanlage von Fig.1, der sich an der Stelle des mit unterbrochener Linie gezeichneten Kreises K in Fig. 1 befindet, wobei der Teleskopsitz im Längsschnitt gezeichnet ist.

The invention and embodiments of the invention will be explained in more detail with reference to an embodiment. It shows:

• Fig. 1 a schematic exhaust system for the internal combustion engine of a motor vehicle with front engine, in plan view with built-in positioning;
• Fig. 2 on a larger scale a telescopic seat of the exhaust system of Fig.1 which is in the place of the broken line K in Fig. 1 is located, wherein the telescope seat is drawn in longitudinal section.

In the Fig. 1 Drawn exhaust system 2 consists - progressing from downstream to downstream - essentially of a manifold 4, a tubing section 6, a catalyst body housing 8 arranged therein with a catalyst body, a tubing section 10, a center muffler 12, a curved extending tubing section 14 and an end muffler 16. The manifold 4 is screwed when installing the exhaust system 2 to the cylinder head of the engine; It combines the exhaust gas flows of four cylinders into a common pipe. The catalyst body in the housing 8 is, for example, a ceramic honeycomb body whose channel walls are coated with a layer which consists essentially of a catalyst support material and the actual catalyst material. The tubing section 14 leads around the rear axle of the vehicle. The muffler 16 is in the installed state of the exhaust system 2 off-center under the trunk floor.

The in Fig. 2 Telescopic seat 20 shown in detail consists essentially of a smaller diameter end portion 22 of a first tubing section 10a, a larger diameter with game 24 end portion 26 of a second tubing section 10b, and three axially consecutive rings 28, 30, 32 in the annulus between the two End areas 22 and 26.

The group of three rings 28, 30, 32 is axially fixed internally between two circumferential sikken 34 which are bent outwardly from the end portion 22. As the end portion 22 and the end portion 26 translate relative to one another in the axial direction, the rings 28, 30, 32 slide along the end portion 26.

The telescopic seat 20 can also be "reversed" executed, d. H. larger diameter end portion at the tubing section 10a and smaller diameter end portion at the tubing section 10b. Another alternative is to bend out the circumferential beads 34 from the end portion 26 inwardly so that the rings 28, 30, 32 are axially fixed in the end portion 26.

All three rings 28, 30, 32 are pressed metal knit rings. The two outer rings 28 and 32 are rings with a support function (although they also have some sealing effect against gas flow through the annulus between end portions 22 and 26). The rings 28 and 30 hold the end portions 22 and 26 in their Teleskopsitz relation, but are not under such high radial bias that axial displacement movements of the Telekopsitzes would be unduly hindered. The middle ring 30 is a ring that has predominantly sealing function. The ring 30 has an outside diameter which is in Fig. 2 from left to right over the axial length of the ring 30 increases conically. The same applies to the inner diameter of the ring 30. Before assembling the telescopic seat 20, the diameter increase of the ring 20 over its axial length was more pronounced, but by assembling the telescopic seat 20, the ring 30 is in its in Fig. 2 right end portion have been compressed diameter reducing. This results in a bias of desirable size.

By the described geometric shape and by the described bias, but preferably also supported by favorable choice of the wire of the wire mesh and / or by favorable choice of knitting the wire mesh and / or by favorable choice of the type of compression of the wire mesh, the middle ring 30th the predominant sealing function.

The muffler 16 may be attached to the motor vehicle with relatively little compliance (e.g., rubber bumps instead of rubber rings) and, therefore, makes little relative movement to the motor vehicle floor. On the total length of the exhaust system 2 resulting in heating thermal expansion are absorbed by the telescopic seat 20.

In particular, in diesel engines and / or exhaust systems without Abgasentgiftung the catalyst body housing can be omitted. The application of the invention in exhaust systems with particle filter is possible. With the drawn in broken line circle Kal another preferred installation point for the telescopic seat 20 is drawn.

Claims (4)

1. Exhaust system for the internal combustion engine of a motor vehicle, having a pipeline (4, 6, 10, 14) with at least one silencer (12; 16), with the exhaust system (2) having at least two sections (4, 6, 8, 10a; 10b, 12, 14, 16) which are connected to one another by means of a sealed, slidable telescopic fit (20), and with the telescopic fit (20) being formed by a relatively small end region (22) of a first pipeline section (10a) and an end region (26), which is relatively large with play (24), of a second pipeline section (10, 10b), with the annular space between the first and the second pipeline sections (10a; 10b) being sealed off in such a way as to allow sliding movements, characterized in that the telescopic fit (20) has three rings, with the two outer rings having a supporting function and the central ring having predominantly a sealing function, and in that the ring which has predominantly a sealing function has a diameter which increases over its length.
2. Exhaust system according to Claim 1, with at least one of the rings being a metal mesh ring, preferably all the rings being metal mesh rings.
3. Exhaust system according to Claim 2, with the at least one metal mesh ring being a pressed metal mesh ring, preferably the metal mesh rings being pressed metal mesh rings.
4. Exhaust system according to one of Claims 1 to 3, with the telescopic fit (20) having, at the inside or the outside, two encircling beads (34) which are spaced apart axially and between which at least one ring is axially fixed.

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