EP1280983A2

EP1280983A2 - Exhaust pipe outlet

Info

Publication number: EP1280983A2
Application number: EP01927503A
Authority: EP
Inventors: Christian Bastin
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-04-26
Filing date: 2001-04-25
Publication date: 2003-02-05
Also published as: WO2001081737A2; WO2001081737A3; AU2001254532A1

Abstract

The invention concerns a terminal element for a gas exhaust pipe. Said element comprises a longitudinal jacket (8) with an intake (7), an outlet (11) and a concentric inner pipe (13) extending along part of the jacket (8), the pipe being laterally perforated and communicating at one end outwards. The jacket intake (7) communicates directly with an exhaust box (1) or with an element of the internal combustion engine exhaust pipe. In the terminal element is provided an obstacle to the linear flow of the expelled gas, which obstacle is bypassed by said flow before reaching outside, passing through the perforated pipe (13) whereof the end is preferably tapered. The outlet can be integrated or adapted to a standard exhaust box.

Description

Gas exhaust duct outlet

The present invention relates to an exhaust pipe outlet for vehicles and to an exhaust pipe integrating this outlet.

It is known that there are several types of exhaust pipes, in particular a conventional type comprising numerous baffles and a so-called "sports" type in which the ejected gases are expanded in a chamber but can follow an essentially straight path. The present invention applies more particularly, but not exclusively, to an improvement to a pot of the latter type.

The "sports" exhaust pipe is most often located at the end of the exhaust pipe coming from the engine, the outlet facing the outside at the rear of the vehicle. The pot has an internal pipe of larger diameter than the pipe of the inlet gas pipe. The conduit is perforated with holes which allows the relaxation in the pot ("pot"), being in the form of a closed sleeve which surrounds the perforated conduit.

It has now surprisingly been found that it is possible to improve the power, the torque, the consumption and in particular the sound of a vehicle by modifying the outlet of an exhaust duct, by in particular a pipe fitted with a sports type pot. The outlet is also much less prone to soiling and does not scale.

According to one aspect of the invention, an additional chamber whose envelope forms, is adapted to the usual configuration, at the terminal outlet of the exhaust duct, that is to say the part generally visible at the rear of the vehicle. at least partially, a volume surrounding a section of pipe perforated on the wall and at least partially closed upstream, said pipe opening onto the outside. This system seems to generate an exit from the concentric gases, gases which advantageously disperse beyond the exit. A particularly advantageous anti-fouling effect has indeed been observed, which constitutes a particular feature of the present invention.

According to one embodiment, an exhaust pipe can be equipped with an additional chamber, forming an expansion chamber and a single baffle with a transverse wall. Preferably, the additional chamber communicates by one or more peripheral openings with a third chamber situated in its extension and comprising an annular volume whose distal part is closed but has an internal wall with holes to communicate with a hollow central cylindrical volume open on the outside.

The exhaust gases expand in a conventional manner in the pot, then pass through a narrowing leading to a second expansion chamber having an opposite central wall obstructing the rectilinear path of the gas. The gas enters the third chamber through peripheral openings to a volume essentially annular before forming a central jet at the outlet, either via openings or perforations in the concentric internal cylinder or pipe delimiting the annular space or by accessing said central cylinder open at the internal end of the third chamber.

The pot will generally but not necessarily be cylindrical or oval in section. The main body can be made up of a perforated central pipe and an envelope joined to the ends of the pipe by two perpendicular flanges with a hole in the center delimiting the conventional expansion chamber. The envelope extends and is closed at its end by a third flange having peripheral openings to a third chamber.

Alternatively according to the invention, the outlet will advantageously consist of an outer envelope (round, oval, rectangular or other) in which the ^ z, whether or not coming from a conventional exhaust pipe or directly from a catalytic system, penetrate, then leave by a perforated central pipe, at least partially closed upstream, which is extended by a cone giving to the open air. The cone can be removed and replaced by a flat flange.

The conical part of the air outlet can extend upstream towards the interior beyond the perforated pipe and therefore overflow inside the latter to form a closed annular volume downstream of said perforated pipe. This characteristic has proved to be interesting for the anti-fouling properties of the proposed system. The invention will be better understood on reading the description of some embodiments provided without limitation, with reference to the accompanying drawings

In these drawings:

- figs. la and lb show a first example of a three-chamber exhaust system - fig. 2 shows a simplified embodiment of the invention in which there is no intermediate chamber

- fig. 3 illustrates the placement of an outlet according to the invention to a pre-existing exhaust pipe

- fig. 4 illustrates a variant of this placement in which the outlet and the exhaust are separated

- figs. 5 and 6 illustrate a variant incorporating air ducts

_ fig. 7 illustrates an exhaust duct outlet element according to the invention - FIGS. 8a and 8b illustrate the placement of an output element according to the invention

- fig. 9 illustrates a variant with air intake

- fig. 10 shows diagrams illustrating the invention in conjunction with the body of a vehicle.

Fig. 1a shows an example of an exhaust pipe 1 according to the invention, of essentially cylindrical shape, comprising an inlet 2 of 50 mmm, a perforated duct 3 of 60 mm in diameter and about 400 mm in length, duct concentric to a outer casing 4 forming annular space 44 for main gas expansion, of conventional configuration, and forming a first chamber. The gas leaves this chamber at 5 to arrive in the expansion chamber 6 then passes through peripheral openings 7, in the third chamber 8 comprising a central cylindrical volume 9 and an annular volume 10 to finally reach the central terminal outlet 11 via openings 12 in the internal cylindrical wall 13 defining said volumes 9 and 10, openings 12 more particularly located at its distal part (rear). The gas in the annular space 10 can also reach the outlet passing through the cylindrical volume 9 open at its end 14. As shown in detail in FIG. lb The central outlet 11 can advantageously be flared to form a divergent frustoconical mouth. A portion of conical wall 15 (fig. Lb) can partially overflow inwards into the cylindrical volume and thus create a volume from which the gas can only flow back to reach the terminal outlet or re-enter the annular space 10. This characteristic seems to favor the cleanliness of the exhaust outlet (absence of condensate).

The three perpendicular flanges 20, 21, 22 are also shown, also shown in plan.

Fig. 2 illustrates a first variant, particularly preferred, in which the outlet from the first expansion chamber gives directly onto the outlet chamber where a second expansion takes place, the obstacle to the rectilinear flow being constituted by the closed or partially closed end 19 of a hollow cylinder or concentric pipe provided with openings for bringing back the deflected and expanded gases towards the central outlet 11. According to an embodiment illustrated in FIG. 3, the outlet part (element forming the third chamber of FIG. 1 or second chamber of FIG. 2) can be assembled to the preceding chambers at an angle, thus forming an angle of for example +/- 10 deg, preferably +/- 5 deg. This arrangement allows during assembly to adapt to the exhaust locations for several types of "universal" model car). It will actually be enough to turn the entire muffler around its longitudinal axis so that the outlet takes a desired orientation (upwards, downwards or to one side), the attachment points being chosen accordingly .

It will also be understood that, according to a variant illustrated in FIG. 4, the device of the invention can be located at a certain distance from a "conventional" exhaust constituting the first expansion chamber 50, instead of being integrated there directly at its outlet. The device of the invention 51 will therefore be connected by a pipe 52. The latter can play the role of second expansion chamber and the obstacle device 53 will constitute the third expansion chamber. This latter variant can also be combined with an air intake with concentric outlet, as illustrated in FIGS. 5 and 6 below.

According to variants illustrated in figs. 5 and 6, the exhaust pipe may in fact include an air passage taken from the pipe creating at the outlet a central flow capable of promoting the ejection of gases from the pipe by vacuum effect when the vehicle is at high speed. An air intake 30, 40 sends the air via a concentric central pipe 31, 41 to the flared outlet 35, 45. A flange 32 with central opening 38 is also illustrated. for the pipe 31, 41 and peripheral opening 37 according to the invention. The presence of the expansion chambers 36, 46 is again noted, preventing the exit of the gases in the form of a central flow, which constitutes one of the fundamental characteristics of the invention.

In the variant according to FIG. 6, the air duct passes longitudinally and centrally through the pot and causes cooling of the gas which is beneficial in terms of noise reduction and efficiency of the exhaust.

This cooling would indeed decrease the density of the gas, therefore its speed, and therefore the noise. The lower density favors the vacuum effect which favors the exit of exhaust gases and reduces turbulence in the exhaust duct.

According to another aspect of the invention, it has been found that the above-mentioned devices could still be advantageously simplified (FIG. 7 et seq.)

It is thus possible to adapt to the outlet 65 of a conventional exhaust, a device 60 according to the invention consisting of an outer envelope 61 (eg round, oval, rectangular) in which the gases coming from the exhaust penetrate , then leave the envelope by a central pipe 62 perforated laterally,. The pipe is closed at 63 on the side of the pot, the bottom 63 of the pipe can however also be perforated. The output 64 of the device need not be conical. However, it has been found that this configuration is particularly advantageous since the dirt at the outlet is considerably reduced. This feature is very interesting for Diesel vehicles.

Without being bound by any explanation, we see that the gases exit more concentrically than for a conventional exhaust outlet, which limits the soiling. The gases would disperse further behind the exit, therefore behind the vehicle.

It is therefore advantageous to transform exhaust pipes, for example by cutting the terminal outlet pipe of a conventional pot and by adapting a device according to the invention available and sold separately, possibly in the form of a kit. The fixing can be done by welding, gluing, crimping etc.

It is also possible to adapt to an existing outlet pipe 72 (FIG. 8), an outlet member 71 consisting of a perforated pipe of smaller diameter and of shorter length which is placed coaxially, the annular space thus formed is closed. on the exit side. The added pipe is closed, or partially closed, on the opposite side. This element is advantageously a perforated pipe, one end of which is closed and the other end, perforated or not, flares to adopt a dimension compatible with the fixing to said exhaust pipe.

One of the other advantages of the device consists in the possibility of providing exhaust outlets 90 integrated in the vehicle body. As schematically illustrated in fig. 10 for vehicle A fitted with a pot conventional exhaust 90 and a vehicle B equipped with an exhaust outlet 90 'according to the invention, the phenomenon of concentric rejection of gases will ensure that the dispersion will be further behind the outlet, thus avoiding 1 heating and body soiling

Finally according to yet another aspect of the invention (fig. 9), one can add to the outlet element an outside air intake, in the direction of travel of the vehicle, as for the exhaust pipes with system integrated anti-fouling described above.

Referring to the diagram in fig. 9, the outside air intake X is in the direction of travel of the vehicle, which causes a pressure P. This pressure P generates a depression at A which facilitates the extraction of gases, thereby reducing the turbulence in the exhaust system. This system can be placed anywhere in the exhaust line, for example the manifold outlet, the piping, a pot, in the catalyst.

Vacuum A is proportional to the speed of the vehicle. The more the engine goes up in revolutions / minute, the more the quantity of exhaust gases increases. As the speed increases, the depression at A therefore increases the suction increases. The evacuation of gases is improved so there is an increase in efficiency.

Claims

claims

1. Exit for exhaust pipe characterized in that it comprises a longitudinal envelope comprising an inlet, an outlet and a concentric internal pipe extending along a part of the envelope, the pipe being perforated laterally and communicating at one end towards the outside, the opposite end being at least partially closed to the rectilinear flow of gas coming from upstream, the inlet of the envelope communicating directly with an exhaust pipe or with an element for conducting the exhaust gas from a combustion engine.

2. outlet for exhaust pipe according to claim 1 wherein the combustion gas pipe comes from an exhaust and / or a catalytic system.

3. An outlet according to claim 1 or 2 characterized in that the open end of the perforated pipe is conical, so that its diameter increases towards said end.

4. Outlet according to any one of the preceding claims, characterized in that the opposite end of said pipe is completely closed.

5. Outlet according to any one of the preceding claims, characterized in that it is in the form of an element adaptable to a conventional exhaust pipe.

6. Output according to the preceding claim characterized in that it is part of a kit comprising fastening elements.

7. outlet element to be adapted to an exhaust pipe outlet, characterized in that it consists of a perforated pipe and closed at one end, of dimension smaller than that of the outlet, the other end being open and comprising a laterally widening element to adapt to and close said pipe outlet.

8. Elements according to the preceding claim characterized in that the element extending laterally is a frustoconical element.

9. Element according to claim 7 characterized in that the element s' widening laterally is a flange perpendicular to the pipe.

10. Exhaust gas, for engines, especially for vehicle engines, comprising a first expansion chamber and an integrated outlet characterized in that there is provided, shortly after the outlet of the expansion chamber an obstacle to linear flow of expelled gas, obstacle that said flow bypasses before accessing the outside.

11. Exhaust according to claim 11 characterized in that the obstacle is a deflecting wall, for example a central wall part perpendicular to the gas flow, delimiting a chamber forming a second expansion chamber, said wall comprising one or more non-central openings.

12. Exhaust according to claim 10 or 11 characterized in that it comprises a third chamber, constituted by the outlet which therefore becomes active, after the said non-central openings, said chamber bringing the flow towards the longitudinal axis of the exhaust pipe.

13. Exhaust according to the preceding claim wherein the third chamber comprises an external annular space communicating with the non-central opening (s), space delimited by a concentric internal tube and perforated at its distal part relative to the main expansion chamber to allow the flow of gas to reach the central cylindrical volume overlooking the outlet.

14. Exhaust according to the preceding claim wherein said inner tube is open at its proximal part and in communication with said annular space.

15. Exhaust according to any one of the preceding claims in which the terminal outlet is flared.

16. Exhaust according to any one of the preceding claims, in which an external air intake is provided brought back via a pipe towards the axis of the exhaust pipe and capable of creating a vacuum effect at the outlet.

17. Exhaust according to any one of the preceding claims in which one or more of the elements according to the main expansion chamber are secured to the pot in a non-concentric manner, or obliquely (angle from 0 to 5 deg.)

18. Exhaust gas, for engines, in particular for vehicle engines, comprising a first expansion chamber and an outlet characterized in that there is provided, beyond the outlet an envelope comprising internal obstacle to the linear flow expelled gas, an obstacle which said flow bypasses before being brought back into a perforated pipe internal to said envelope facing the outside.

19. An exhaust system according to any one of claims 10 to 18 wherein the first chamber and the obstacle chamber are separated while being connected by a section of a gas exhaust duct.

20. Vehicle comprising an exhaust pipe outlet or an exhaust pipe according to any one of the preceding claims.

21. Vehicle according to the preceding claim wherein the outlet of the muffler is flush with or is integrated into the bodywork.

22. Exhaust gas outlet system characterized in that the gases, prior to rejection, are brought into a chamber enveloping a central space communicating with the outside, said chamber being separated from the central space by at least one wall perforated.

23. Exhaust gas outlet anti-fouling system comprising an element according to any one of the preceding claims.