DE19645619A1 - Exhaust pipe system for removing exhaust gas from an internal combustion engine - Google Patents

Abstract

The invention concerns an exhaust gas system (10) for discharging exhaust gases from an internal combustion engine (6), said system having a plurality of exhaust gas outlets (4) passing through a connection section (13). The exhaust gas system is a bundle of pipes (15) comprising a plurality of inner pipes (12). The inner pipes (12) are guided inside a casing pipe (11) and are individually connected to connection pipes (17) which are connected to the exhaust gas outlets (4).

Description

The present invention relates to an exhaust pipe system according to the Ober Concept of claim 1. Exhaust gases from an internal combustion engine are from Exhaust pipe systems dissipated. These are generally on the motor side a plurality of exhaust outlets connected. In many cases, they lead the exhaust gases of the engine up to an upstream of a catalytic converter conical diffuser that matches the cross section of the cable to the cross section of the Catalyst expanded.

An exhaust gas pipe system is known which has a pipe well in a partial section del having a plurality of inner tubes within a Jacket tube are guided and generally a segment of a circle Have cross-section. The inner tubes are over a common flange and a plurality of connection pipes with the exhaust gas outlets of the engine connected. In this way, the exhaust gas back pressure of a cylinder reduce to the other cylinders compared to an exhaust pipe system in which the connecting lines on the flange in a common Outlet pipe. For the maximum torque of a combustion It is often cheap for motors if they are assigned to the individual exhaust gas outlets Neten outlet lines are as long as possible before they are in a common Exhaust system open. Compared to conventional multi-strand exhaust gas tion systems has a pipe section with a plurality of in a jacket tube integrated inner tubes have a smaller surface area and therefore a smaller surface area  Heat loss to the outside and due to thinner inner walls and only one bearing outer tube also has a lower heat capacity. Both are for the Area of an exhaust pipe system between the engine and a catalytic converter Favorable, because when the engine is cold started, the catalytic converter switches to the catalytic conversion temperature required comes. With previous ones Systems, however, is the so-called manifold, i.e. H. the first one directly the area of the exhaust system connecting the exhaust gas outlets still conventionally designed and has thick walls and a large surface on. Also a flange connection to a subsequent multiple pipe system stem still has a relatively high additional heat capacity.

Also known is a manifold with a relatively small surface area, in which a manifold is guided along the exhaust gas outlets of an engine. Connection lines lead from the exhaust gas outlets into individual ones spaced tube openings of the header. The manifold does not contain any Inner tubes. The exhaust back pressure of one cylinder on the other cylinders is therefore relatively large with short connection pipes.

The object of the present invention is to provide a near-engine area Specify multi-line exhaust pipe system, which at low heat capacity quantity and small surface area directly connected to the exhaust outlets can be and is inexpensive to manufacture.

The object is achieved by an exhaust pipe system with the Features of claim 1 solved. Advantageous further developments are Subject of the dependent claims.

In the exhaust pipe system according to the invention, the inner pipes are individually included Connection lines connected to the operation of the internal combustion engine Guide the exhaust gas from the exhaust gas outlets of the engine to the inner pipes. At the  State of the art, however, the connection section has a common Flange with which the transition from the connecting lines to the Inner tubes is reached. An advantage of the invention is that individual connections gen can be created easily and inexpensively. This can happen with for example done by welding. By not having one common flange and the application of the pipe-in-pipe system up to The immediate vicinity of the exhaust gas outlets of the internal combustion engine can cause heat Measurement losses of the exhaust gas in the cold start phase of the internal combustion engine can be significantly reduced, which makes a downstream catalyst quick responds.

In an advantageous embodiment of the invention, the connecting lines are continued as a fanning bundle of inner tubes. Fastening separate connecting lines to the inner pipes is therefore no longer necessary. There are different variants of this configuration. With one before drawn variant, the inner tubes have a shape other than in cross section the connecting lines at the exhaust gas outlets. The latter point more appropriately have a circular cross-section, for example, by thorning of the original circular segment-shaped cross section of the inner tubes can be.

In an advantageous embodiment of the exhaust pipe according to the invention systems, the inner tubes are at least along the closest to the engine lying section of the casing tube twisted out. With a continuation In this embodiment, the inner tubes are spaced apart from one another te single pipe openings connected to the connecting lines. From There are different variants of this configuration, namely: the inner tubes are uniquely connected to the connecting lines, a plurality of Inner pipes are connected to a plurality of connecting lines merge outside the casing tube, or a plurality of separa  ten connecting lines is connected to the same inner tube. All three Variants are the connection between an inner tube and the An end section through a single pipe opening to a single piece of a Connecting cable.

A further development is particularly advantageous in which the casing tube has a straight section, in which the individual tube openings approximately along a straight line. This is the straight section along the exhaust outlets of the internal combustion engine, which are usually also in a straight the line. There are versions of this configuration with special the short connecting lines. Advantageously, all of them form the same Connection lines connect the exhaust outlets to the individual pipe openings. To make this possible, the distances are the single pipe openings are chosen so that they match the distances between the exhaust gas outlets they are the same as each other.

A jacket pipe with two non-twisted inner pipes can also be used connection of connecting lines to different inner tubes close along the Gas outlets can be arranged when the partition between the inner pipe is directed towards the gas outlets. The connecting lines can then open tangentially into one of the inner tubes.

It is expedient if the inner tubes within one another within the casing tube somewhat before the junction with a catalyst cone to have. In this way, the effect that in a downstream catalytic converter or a measuring chamber in front of it with a lambda probe may be uneven across the flow cross distributed exhaust gas flows occur. With an advantageous further training are partially cut out like tongues at the connection openings Wall pieces are bent and protrude into the interior of the inner tubes.  

Embodiments are preferred for the present invention in which the cross section of the casing tube is circular and the inner tubes are circular Fill out the cross-section mentally. The inner cross is expedient cuts of the inner tubes selected so that the total in each inner tube flow equal amounts of exhaust gas per cross-sectional area. With four-cylinder Internal combustion engines are jacket tubes with four inner tubes or jacket tubes with two inner tubes preferred. In the latter case there are two Exhaust outlets connected to one of the two inner pipes.

In further refinements, the exhaust pipe system has a plurality of jacket pipes, each having a plurality of inner pipes. In this way, a variety of desired configurations for internal combustion engines with different Number of exhaust outlets and desired number of exhaust lines achieve.

Further features and preferred configurations of the invention Exhaust pipe system are described with reference to the drawing. The drawing The example shows embodiments, but the invention is not limited.

The individual figures in the drawing show:

Fig. 1 shows an exhaust system with two inner tubes are guided partially twisted,

Fig. 2 to 5 cross-sections through the processing system shown in Fig. 1 Abgaslei,

Fig. 6, an exhaust pipe system with four connecting lines extending auffächerndes bundle are continuous as far out of inner tubes,

Fig. 7 shows a cross section through the assembly shown in Fig. 6 exhaust system before the opening of the bundle Man telrohrs,

Fig. 8 is a longitudinal section through a section of a man telrohrs with two inner tubes, which have two connection openings and

Fig. 9 shows a cross section through Fig. 8 along the line IX-IX.

Fig. 1 shows an inventive exhaust pipe system 10 which is connected to a catalyst cone 2, which extends the wire cross-section to the catalyst 1 side. The exhaust pipe system 10 leads the exhaust gases of the internal combustion engine 6 from its exhaust outlets 4 through a jacket tube 11 with inner tubes 12 to the catalyst cone 2 . The connection section 13 has four connecting lines 17 , each of which connects an exhaust gas outlet 4 of the internal combustion engine 6 to a single pipe opening 18 in the casing pipe 11 . The jacket tube 11 has a straight jacket tube section 14 , in which the two inner tubes 12 are guided twisted. The two inner tubes 12 are not twisted in the curved jacket tube section which adjoins the straight jacket tube section 14 and leads to the catalyst cone 2 . The tube bundle 15 thus has a twisted and an untwisted section.

FIGS. 2 to 5 show cross-sections through that shown in Fig. 1 exhaust gas conduit system at the intersections I to IV, each of which are at the level of a single tube opening 18. Starting in the order of FIG. 2, the first inner tube 42 and the second inner tube 43 , which are drilled together, are each rotated through 90 ° to the following individual tube opening 18 due to the twisting. In this way, the connecting lines 17 are connected to the second inner tube 43 at the intersection lines I and IV, whereas the connecting lines 17 are connected to the first inner tube at the intersection lines II and III. With the same strength of the twist, connections between the connecting lines at the level of section lines I and II or III and IV could also be created. If the twist is stronger, connections between I and III or II and IV are possible. The inner pipes shown in Fig. 2 to 5 42, 43 in the circular cross-sectional casing 21 are executed as in cross-section semi-circular inner tubes which fill the internal cross section of the casing tube 21 approximately.

Fig. 6 shows an exhaust pipe system with four internal tubes 22 in a tube bundle 25. The connecting lines 27 between the exhaust gas outlets 4 and the inner tubes 22 are designed as ends of the inner tubes 22 . The connecting section 23 thus has four bent pipe ends fanning out on the exhaust gas outlets 4 . In contrast to the jacket tube 11 shown in FIG. 1, the jacket tube 21 does not have a single tube opening, but instead a common opening for the tube bundle 25 at the bundle opening 28 .

FIG. 7 shows a cross section through the exhaust gas line system 20 on the section line V. It can be seen that the inner tubes in the casing tube 21 are designed as inner tubes 52 with a cross-section that is similar to a quarter-circle segment as they fill the inner cross section of the jacket tube 21 .

In Fig. 8, a portion of a jacket tube 31 is shown with a first inner tube 32 and a second inner tube 33 , which have at least one connecting opening 34 with each other. At the connection opening 34 , a tongue-like, partially cut-out wall piece is bent outwards on the one and once on the other inner tube 32 and projects into the interior of the respective inner tube 32 , 33 , the wall of which is completely cut out at the connection opening 34 . The exhaust gas flow profiles are shown by arrows in the left side of FIG. 5. Through these and similar arrangements, a better distribution of the exhaust gases flowing in pulsed fashion in one of the two inner tubes is distributed to both inner tubes, as a result of which a downstream lambda probe and a downstream catalyst are flowed more evenly. In principle, similar configurations are also possible for four inner tubes, but it is better to first combine them in pairs and then design the transverse distribution as described above.

The present invention simplifies the exhaust system of combustion motors and causes a faster response of a catalytic cleaning supply device, whereby the pollutant emissions in the cold start phase of an internal combustion engine is reduced and also later at low load the catalyst temperature would drop below that required for implementation necessary temperature is avoided.  

Reference list

1

catalyst

2nd

Catalyst cone

4th

Exhaust outlet

6

Internal combustion engine

10th

Exhaust pipe system

11

Jacket pipe with a straight piece along the engine

12th

Partially twisted inner tube

13

Connection section to straight jacket pipe section

14

Straight casing section

15

Tube bundle with twisted inner tubes

17th

Connection line to individual openings

18th

Single pipe opening for connection to the exhaust outlet

20th

Exhaust pipe system with bundle opening

21

Jacket tube with bundle opening

22

Inner tube guided without twisting

23

Connection section to bundle opening

25th

Pipe bundle with inner pipes running in the direction of the casing pipe

27

Connection line to the bundle opening

28

Bundle opening

31

Casing pipe

32

first inner tube with half-sided transition

33

second inner tube with half-sided transition

34

Connection opening

35

second transition

36

first transition

42

first inner tube with semicircular cross section

43

second inner tube with semicircular cross section

52

Inner tube with quarter-circular cross-section

Claims (7)

1. exhaust pipe system ( 10 ; 20 ) for discharging exhaust gas from an internal combustion engine ( 6 ) with a plurality of exhaust gas outlets ( 4 ) through a connection section ( 13 ; 23 ), the exhaust pipe system being a tube bundle ( 15 ; 25 ) with a plurality of inner tubes ( 12 ; 22 ; 32 ; 42 ; 43 ; 52 ), which are guided within a casing tube ( 11 ; 21 ; 31 ), characterized in that the inner tubes ( 12 ; 22 ; 32 ; 42 ; 43 ; 52 ) individually with Connection lines ( 17 ; 27 ; 37 ) are connected, which are connected to the exhaust gas outlets ( 4 ). 2. Exhaust pipe system according to claim 1, characterized in that the connecting lines ( 17 ; 27 ) continuously as a fanning bundle ( 25 ) of inner tubes ( 22 ; 32 ; 42 ; 43 ; 52 ) from the casing pipe ( 21 ) individually to the exhaust gas outlets ( 4 ) are continued. 3. Exhaust pipe system according to claim 1, characterized in that the inner tubes ( 12 ) are guided at least along the section of the exhaust system in the jacket pipe ( 14 ) lying closest to the exhaust gas outlets ( 4 ), the exhaust gas outlets ( 4 ) being in one plane short connecting lines ( 17 ) are connected to the various inner tubes ( 12 ). 4. Exhaust pipe system according to claim 1, characterized in that a jacket tube ( 11 ) with two inner tubes ( 42 , 43 ) along the exhaust gas outlets ( 4 ), the partition between the inner tubes ( 42 , 43 ) approximately on the exhaust gas outlets ( 4th ) is directed, and the connecting lines ( 17 ) connect the exhaust gas outlets ( 4 ) either tangentially to one inner tube ( 42 ) or tangentially to the other inner tube ( 43 ). 5. Exhaust pipe system according to claim 1, 3 or 5, characterized in that the inner tubes ( 12 ; 32 ; 42 ; 43 ; 52 ) are connected to each other by individual tube openings ( 18 ) with the connecting lines ( 17 ; 27 ). 6. Exhaust pipe system according to one of claims 1 to 5, characterized in that the inner tubes ( 22 ) within the jacket tube ( 21 ) before entering a catalyst cone ( 2 ) have at least one connection opening ( 34 ), preferably with flow control means ( 35 ) for evenly distributing the exhaust gas on the inner tubes ( 22 ). 7. Exhaust pipe system according to claim 6, characterized in that at the connection opening ( 34 ) tongue-like partially cut out wall pieces ( 35 ) of the inner tubes ( 32 ) are bent and in each case protrudes into the interior of an inner tube ( 32 ), preferably in such dimensions. that in each case about half of flowing in an inner ear (32), gas is diverted into an adjacent inner tube (32).