WO2004018849A2

WO2004018849A2 - Device for depolluting engine exhaust gases

Info

Publication number: WO2004018849A2
Application number: PCT/FR2003/002561
Authority: WO
Inventors: Gérard LERDUNG; Willy Mougin
Original assignee: Faurecia Systemes D'echappement
Priority date: 2002-08-23
Filing date: 2003-08-21
Publication date: 2004-03-04
Also published as: AU2003274272A1; FR2843776A1

Abstract

The invention relates to a device for depolluting engine exhaust gases. The inventive device (10) comprises a housing (12) and a depolluting element (14). The aforementioned housing (12) comprises an essentially-cylindrical body (20) which contains the depolluting element (14) and at least two holes (16, 18) which are used to introduce and discharge the exhaust gases. According to the invention, at least one of said holes is a lateral hole (18) which is defined at least partially through the essentially-cylindrical body (20). Moreover, the device also comprises a solid plug (50) which is used to seal one end of the body (20), said plug (50) defining at most only part of the lateral hole (18). The invention is suitable for motor vehicles.

Description

Engine exhaust gas cleaning device

The present invention relates to a device for depolluting exhaust gases from an engine, of the type comprising a casing and a depollution member, which casing comprises a body having at least one generally cylindrical section in which said organ is disposed. depollution, and at least two orifices for the introduction and evacuation of exhaust gases.

The invention further relates to a method of manufacturing such an exhaust gas depollution device.

The exhaust lines of motor vehicle engines, and in particular diesel engines, are fitted with pollution control devices allowing the treatment of gases from the engine.

This pollution control device consists for example of a catalytic converter and / or a particle filter.

In order to ensure the channeling of the exhaust gases through the pollution control device, the latter is placed in an envelope having a gas introduction orifice and a gas evacuation orifice.

For reasons of convenience in manufacturing pollution control devices, the envelope comprises a generally cylindrical body in which is engaged the pollution control element which is also cylindrical. At the ends of the body, on either side of the depollution member, are converged end sections allowing the sealed connection of the body to the exhaust pipes of the exhaust line. These converging connection sections frequently consist of conical sections, commonly designated by cones, the end of which has the largest section is engaged and welded to one end of the cylindrical body.

In order to allow a certain standardization of pollution control devices and therefore obtaining a lower manufacturing cost, it is known to use, for several types of vehicle, the same body and the same pollution control device. The different types of pollution control devices are differentiated from each other only by the shape and dimensions of the converging end sections. Thus, for each type of vehicle, the two end sections are specifically designed and manufactured, so that they fit into the space available in the vehicle for the exhaust line.

However, the differentiation of the pollution control devices from their two converging end sections makes the different types of pollution control devices relatively expensive.

The object of the invention is to provide a pollution control device and a manufacturing method which make it possible to further reduce the cost of manufacturing pollution control devices. To this end, the subject of the invention is a device for depolluting the exhaust gases from an engine, of the aforementioned type, characterized in that at least one of the orifices is a lateral orifice delimited at least partially through of said body, and in that the device comprises a solid plug closing off one end of the body, which buffer at most only partially defines said lateral orifice.

According to particular embodiments, the depollution device includes one or more of the following characteristics:

- at least one lateral orifice is delimited only through said body; - At least one lateral orifice is delimited partially through said body and partially by said buffer;

- the full buffer defines inside the envelope a channel partially extending the lateral orifice;

- At least one lateral orifice is bordered by a flange for docking an exhaust pipe, which flange protrudes outside said envelope;

- The collar is formed at least partially by a stretched part made of material with the body and at most only a stretched part made of material with the full pad; - The surface of the full pad closing one end of the body is greater than or equal to the cross section of the depollution member;

- At least one lateral orifice is defined at least partially through the body in a part of the body which is not generally cylindrical; and - Said non-generally cylindrical part of the body has a cross section smaller than that of said generally cylindrical section.

The subject of the invention is also a method of manufacturing an exhaust gas depollution device as defined above, characterized in that it comprises the steps of:

- Form a body having at least one generally circular section;

- at least partially provide a lateral orifice through the body; - engage a depollution organ in the body; and

- Bring a full sealing plug at one end of the body, which buffer at most only partially delimits the lateral orifice.

The invention will be better understood on reading the description which follows, given only by way of example and made with reference to the drawings, in which:

- Figures 1 and 2 are views respectively in longitudinal section and in perspective of a first embodiment of a device for cleaning up exhaust gas from an engine according to the invention;

- Figures 3 and 4 are views identical to Figures 1 and 2 of a second embodiment of a pollution control device according to the invention; and

- Figure 5 is a longitudinal sectional view of a third embodiment of a pollution control device according to the invention.

FIG. 1 shows a device 10 for cleaning up exhaust gases from a motor vehicle engine, for example a diesel engine.

This device comprises an envelope 12 and a pollution control device 14 contained in the envelope. The pollution control device 14 is cylindrical with a constant section. The pollution control device 14 consists for example of a catalytic converter, that is to say a porous substrate in which catalytic materials are incorporated or of a particle filter, that is to say of a structure porous structure defining adjacent longitudinal channels alternately closed at one or the other of their ends.

The casing 12 comprises an orifice 16 for entering the exhaust gases and an orifice 18 for discharging the exhaust gases, the pollution-removing member 14 being disposed between these two orifices.

More specifically, the envelope 12 comprises a body 20 having a generally cylindrical section 20A of constant section. This body is formed for example by a sheet rolled on itself and whose longitudinal edges are secured to one another by a longitudinal weld. The body 20 thus has a longitudinal axis X-X.

In the envisaged embodiment, the body 20 is generally cylindrical over its entire length.

The section of the body 20 is greater than the cross section of the pollution control member 14. The latter is held in the body 20 by a sheet of fibers 22 engaged around the pollution control member 14 between the outer lateral surface of the latter. ci and the internal surface of the body 20.

At one end, the body 20 is extended by an end section 24 of progressively decreasing section up to the inlet 16 for introducing the exhaust gases. This end section 24 is attached and has, at its end of larger diameter, a cylindrical section 26 engaged in the end of the body 20 and held therein by a peripheral weld 28.

The reduced end of the end section 24 has a tabular section 30 for coupling to a pipe, not shown, of an exhaust line.

According to the invention, at least one of the orifices provided in the envelope 12 is a lateral orifice delimited at least partially through the body.

More specifically, in the embodiment of Figures 1 and 2, the body 20 extends beyond the pollution control member 14 on the side opposite to the end section 24. This extension is cylindrical with a section identical to that of the body part 20. The exhaust gas discharge orifice 18 is formed directly through the extension of the body. In particular, this extension has a stitching delimited by a peripheral flange 40 projecting outside the envelope 12. The axis of the flange YY generally extends perpendicularly to the axis XX of the body.

This flange consists of a stretched part of the body made of material with its current part. The flange constitutes a barrel stretch formed by forging the sheet metal constituting the body 20.

The end of the body defined by the extension extending beyond the member 14 is generally inclined relative to the axis X-X. The orifice 18 is formed in the longest part of this extension.

The end of the beveled body 20 is closed by a full pad 50 engaged in the open end of the body 20. This full pad is defined by a generally elliptical bottom wall 52 bordered on the outside by a flange 54 applied against the inside surface of the body 20. The pad 50 is welded at its periphery to the body 20.

The surface of the bottom 52 of the pad is greater than the cross section of the pollution control device 14.

For the manufacture of such a pollution control device, the body 20 is first formed. For this purpose, a sheet is for example rolled on itself and welded longitudinally.

The lateral orifice 18 is formed through the body 20 by puncture and stretching of the material obtained by plastic deformation thereof until the flange 40 is obtained. This stretching is obtained for example using a punch dragging the material into a complementary hollow shape.

The pollution control device 14, previously surrounded by the sheet 22, is then introduced into the body from one of its open ends. The closure pad 50 and the end section 24 are then attached to each of the ends and are welded thereto.

In Figures 3 and 4 is shown a second embodiment of a pollution control device 100 according to the invention. In this embodiment, the elements identical or analogous to those of the first embodiment are designated by the same reference numbers.

In particular, the pollution control device 14, the retaining ply 22 and the end section 24 are identical to those of the first embodiment.

The body denoted 120 of the envelope is, in its current part, identical to the body 20 of the first embodiment. In particular, it is generally cylindrical over its entire length so that it forms a generally cylindrical section 120A.

On the other hand, in this embodiment, the orifice 18 for evacuating the exhaust gases is only partially delimited by the body 120, this orifice being further partially delimited by the full sealing pad denoted 150. More precisely, at its end opposite to that carrying the end section 24, relative to the pollution control member 14, the body 120 has an extension generally ending in an inclined profile relative to the longitudinal axis XX of the body.

In its part of greater length, the extension has a semicircular re-entrant clearance 160 bordered on the outside by a half-flange 162 formed from a stretched part made integrally with the body 120.

Similarly, the tampon 150 has, at its periphery, in the region opposite the clearance 160, a deformation forming a channel 170 of progressively increasing section from the middle portion of the tampon to its periphery. This channel is extended radially beyond the general periphery of the buffer by a half-flange 172 defining a clearance 174 extending the channel 170. The half-flanges 162 and 172 are complementary to form together a cylindrical flange substantially identical to the flange 40 of the first embodiment.

At its periphery, outside the channel 17Q, the buffer 150 has a peripheral rim 180 facing the pollution control device 14 and received inside the body 120. The buffer is welded along its peripheral rim to the body 120. The two half-flanges 162, 172 are welded to each other along longitudinal welding sections 182.

The manufacture of the pollution control device Î00 is substantially similar to that of the device 10 of the first embodiment. During the manufacture of the body, only half of the orifice 18 is defined in the body by formation of the half-flange 168. Furthermore, before assembly, the full sealing plug 150 is formed with the channel 170 and the half-collar 162.

After introduction of the depollution device 14 surrounded by the ply 22, the pad 150 is engaged at the end of the body 120 and is welded thereto along its entire periphery with the exception of the zone of the orifice 18, only the two longitudinal welds 182 being produced between the two half-flanges 162, 172.

FIG. 5 shows a third embodiment of a pollution control device 200 according to the invention. Elements identical or analogous to those of the first embodiments are designated by the same reference numbers.

In this embodiment, the body denoted 220 has a cylindrical section 220A for receiving the pollution control device 14 and a non-cylindrical section 220B in which the discharge orifice 18 is formed. The cylindrical section 220A is partially closed at one end by the end section 24.

The section 220B has from its connection end to the generally cylindrical section 200A a progressively decreasing section up to an open end defining a collar 230 for receiving a closure pad 250.

The section 220B thus has an inclined surface 260 extending inside the space delimited by the extension of the generally cylindrical section 220A.

The evacuation orifice 18 is formed through this inclined wall 260. It has, as in the first embodiment, a peripheral flange 40 projecting outside the envelope 12. The axis of the flange YY defines with the axis XX of the body an angle of approximately 45 °, these two axes being coplanar. For the manufacture of such a pollution control device, a generally cylindrical body along its entire length is formed.

The section of one of the ends of the body is reduced, for example, by flow spinning in order to form the inclined surface 260 and the collar 230. The discharge orifice 18 is then formed in the inclined wall

230, after which, the pollution control device 14 is introduced into the cylindrical section 220A. The closure plug and the end section 24 are then put in place.

It will be understood that, in these different embodiments, only one of the orifices is formed from an added end section, the other end being formed at least partially in the body itself.

Thus, the same body and the same end pad can be used for several types of pollution control device, only one of the end sections having to be modified to differentiate the different pollution control devices according to the vehicles on which they must be implanted.

Alternatively, the two orifices can be delimited at least partially by the envelope.

Advantageously, and whatever the embodiment, the body has, in the part where the lateral orifice is formed, a local excess thickness in order to ensure, during the shaping of the flange 40 by stretching the material, that the thickness of this flange is sufficient to allow the connection of an exhaust pipe.

This additional thickness is obtained for example by laser spot welding of a metal plate before stretching the material to form the flange 40.

Claims

CLAIMS 1.- Device (10; 100; 200) for depolluting the exhaust gases of an engine comprising a casing (12) and a depollution member (14), which casing (12) comprises a body (20; 120 ; 220) having at least one generally cylindrical section (20A; 120A; 220A) in which said pollution control member (14) is disposed, and at least two orifices (16, 18) for the introduction and evacuation of the gases d exhaust, characterized in that at least one of the orifices is a lateral orifice (18) delimited at least partially through said body (20; 120; 220), and in that the device comprises a full buffer (50 ; 150; 250) for closing off one end of the body (20; 120; 220), which buffer (50; 150; 250) at most only partially delimits said lateral orifice (18).

2.- Device according to claim 1, characterized in that at least one lateral orifice (18) is defined only through said body (20; 220).

3.- Device according to claim 1, characterized in that at least one lateral orifice (18) is partially defined through said body (120) and partially by said pad (150).

4.- Device according to claim 3, characterized in that the full pad (150) defines inside the envelope (12) a channel (170) partially extending the lateral orifice (18).

5.- Device according to any one of the preceding claims, characterized in that at least one lateral orifice (18) is bordered by a flange (40; 162, 172) for docking an exhaust pipe, which flange projects outside of said envelope (12).

6.- Device according to claim 5, characterized in that the flange (40; 162, 172) is formed at least partially by a stretched part coming integrally with the body (20; 120) and at most only a stretched part coming of material with the full pad (50; 150).

7.- Device according to any one of the preceding claims, characterized in that the surface of the full pad (50; 150) closing one end of the body (20; 120) is greater than or equal to the cross section of the member depolution (14).

8.- Device according to any one of the preceding claims, characterized in that at least one lateral orifice (18) is defined at least partially through the body in a part (220B) of the body which is not generally cylindrical.

9.- Device according to claim 8, characterized in that said part of the body (220B) not generally cylindrical has a cross section smaller than that of said generally cylindrical section (220A).

10.- Device according to any one of the preceding claims, characterized in that the body (12) has an additional thickness in the region of the or each lateral orifice (18).

11.- Method for manufacturing a device (10; 100) for depolluting exhaust gases according to any one of the preceding claims, characterized in that it comprises the steps of:

- forming a body (20; 120) having at least one generally circular section (20A; 120A);

- at least partially form a lateral orifice (18) through the body (20; 120);

- engaging a depollution organ (14) in the body; and

- Attaching a full sealing pad (50; 150) to one end of the body (20; 120), which pad (50; 150) at most only partially delimits the lateral orifice (18).