Exhaust system

Abstract

An exhaust system has an exhaust tailpipe cover provided in an outlet region and, on the inside, contains inner exhaust pipes which are disposed spaced apart from the exhaust tailpipe cover by a passage. The passage in the exhaust tailpipe cover results in the exhaust tailpipe cover being exposed to as little thermal loading as possible and avoids transmitting heat to a surrounding vehicle rear part, in particular made of plastic.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic, exploded perspective view of an end region of an exhaust system with exhaust pipes, inner exhaust pipes and an exhaust tailpipe cover, according to the invention;

FIG. 2 is a diagrammatic, perspective view of the end region of the exhaust system assembled together with the exhaust tailpipe cover;

FIG. 3 is a diagrammatic, perspective view of a holding device on the exhaust pipes in the form of a protruding holding tongue with a threaded nut;

FIG. 4 is a diagrammatic, enlarged perspective view of a dovetailed receptacle in the exhaust tailpipe cover for receiving the holding device shown in FIG. 3;

FIG. 5 is a diagrammatic, perspective view of the inner exhaust pipes with resilient clamping elements and supporting limbs;

FIG. 6 is a diagrammatic, perspective view of the fitted end region of the exhaust system with a visible gap and air throughflow passage between the inner exhaust pipes and the exhaust tailpipe cover; and

FIG. 7 is a diagrammatic, section view through the exhaust tailpipe cover with the inserted inner exhaust pipe and illustrated passage when installed in a vehicle rear part.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown an end region of an exhaust system 1 of a motor vehicle, which exhaust system 1 has an exhaust pipe 2 and two exhaust pipes 3, 4 branching off therefrom for connecting to inner exhaust pipes 5, 6 which adjoin them upstream. The latter are held in an exhaust tailpipe cover 7 which is pulled on over them and protrudes, for example, through a cutout A of a vehicle rear part 8a which is illustrated in more detail in FIG. 7. The exhaust gas flow flows through the exhaust pipe 2 in the arrow direction P, branches into the two adjoining exhaust pipes 3, 4 and then flows into the inner exhaust pipes 5, 6 and then discharges to the outside.

The exhaust pipe 2 and the adjoining exhaust pipes 3, 4 are connected to the exhaust tailpipe cover 7 via a holding device 10 (FIG. 3) which is fastened to the exhaust pipes 3, 4. The holding device 10 contains a protruding holding tongue 11 which is disposed in a vertical center plane of the exhaust pipes 3, 4 and can be introduced into a T-groove-shaped receptacle 12 or a similar receptacle of the exhaust tailpipe cover 7, and the holding tongue 11 is supported in a precise position and is secured via a fastening screw 14.

For this purpose, the holding tongue 11 has a fixed threaded nut 13 into which the fastening screw 14 is screwed, for which purpose the latter is inserted into a bore 15 of the exhaust tailpipe cover 7.

Furthermore, the inner exhaust pipes 5, 6 are connected to the exhaust tailpipe cover 7, for which purpose the inner exhaust pipes 5, 6 have, on their outer circumferential surface, two opposite supporting brackets 16, 16a which, when pushed into the exhaust tailpipe cover 7, are supported on steps disposed on a side of the receptacle 12 which can be secured in the steps via screws 17, 18. For a spaced-apart mounting in the exhaust tailpipe cover 7, a plurality of resilient clamping elements 19 are disposed distributed over an outer circumference of the inner exhaust pipes 5, 6 (see FIG. 5).

So that the exhaust gas flow P can flow via the exhaust pipe 2 and the adjoining exhaust pipes 3, 4 into the inner exhaust pipes 5, 6, the latter have a tight connection to the exhaust pipes 3, 4. Their tight connection contains in each case a widened pipe portion 20, into which an opposite pipe end 21 of the exhaust pipes 3, 4 can be plugged.

The inner exhaust pipes 5, 6 are disposed in the exhaust tailpipe cover 7 in such a manner that an air passage K running all the way around is formed between the inner exhaust pipes 5, 6 and the exhaust tailpipe cover 7, and therefore, in the driving mode, an air throughflow can take place so that removal of heat is ensured and the exhaust tailpipe cover 7 is no longer exposed to any substantial radiation of heat and the vehicle rear part is kept largely free from harmful effects of heat.

The exhaust tailpipe cover 7 can be composed, for example, of an aluminum casting or of a sheet-metal part, with it being possible for the inner exhaust pipe 5, 6 to be composed of special steel, for example, titanium.

Claims

1. An exhaust system for a motor vehicle, comprising: two exhaust pipes;a holding device;an exhaust tailpipe cover supported by said exhaust pipes and disposed in a cutout of a vehicle rear part, said exhaust tailpipe cover connected to at least one of said exhaust pipes via said holding device; andtwo individual inner exhaust pipes disposed in each case between said exhaust tailpipe cover and said exhaust pipes and plugged onto said two exhaust pipes, said individual inner exhaust pipes connected fixedly to said exhaust tailpipe cover and together creating a continuous passage formed all a way around between said two individual inner exhaust pipes and said exhaust tailpipe cover accommodating them.

2. The exhaust system according to claim 1, wherein: said holding device is fastened between said two exhaust pipes;said exhaust tailpipe cover has a receptacle; andsaid holding device has a threaded screw and a protruding holding tongue disposed in a vertical center plane of said two exhaust pipes, said protruding holding tongue being pushed into said receptacle of said exhaust tailpipe cover and is held via said threaded screw.

3. The exhaust system according to claim 2, wherein: said exhaust tailpipe cover has a bore formed therein; andsaid holding device has a threaded nut fastened on said protruding holding tongue, and said threaded screw being guided in said bore of said exhaust tailpipe cover to said threaded nut and can be connected to said threaded nut.

4. The exhaust system according to claim 2, wherein said two inner exhaust pipes have screwing fasteners, outer circumferential surfaces and a plurality of outwardly prestressed, resilient clamping elements disposed on said outer circumferential surfaces, said resilient clamping elements, when inserted in said exhaust tailpipe cover, are supported in a manner held on an inner wall of said exhaust tailpipe cover, and a fixed connection to said exhaust tailpipe cover takes place via said screwing fasteners.

5. The exhaust system according to claim 4, wherein: said exhaust tailpipe cover has stops disposed adjacent said receptacle and said receptacle is a dovetailed receptacle; andsaid two inner exhaust pipes have mutually facing, protruding supporting limbs fastened to said outer circumferential surfaces and, when introduced into said exhaust tailpipe cover, said protruding supporting limbs are supported on said stops and are secured via said screwing fasteners.

6. The exhaust system according to claim 1, wherein said two inner exhaust pipes each have a widened pipe portion receiving said two exhaust pipes plugged in tightly, said two inner exhaust pipes having free ends facing away from said widened pipe portion and have, all a way around, an air gap with respect to an inner circumferential surface of said exhaust tailpipe cover at least at a discharge region of exhaust gases.

7. The exhaust system according to claim 1, wherein: said exhaust tailpipe cover ends in mouth regions and has an inner wall; andsaid inner exhaust pipes widen in a trumpet-shaped manner in a discharge region defining mouth regions, and an air gap is formed between said mouth regions of said exhaust tailpipe cover and said mouth regions of said inner exhaust pipes, and said inner exhaust pipes are each disposed at a distance from said inner wall in said exhaust tailpipe cover, and said continuous passage is produced as an air gap insulation.

8. The exhaust system according to claim 1, wherein said exhaust tailpipe cover is composed of a single-part cast part, and said inner exhaust pipes are composed of special steel and are of a thin-walled configuration.