FR2878283A1 - EXHAUST GAS TREATMENT DEVICE FOR MOTOR VEHICLE AND CORRESPONDING EXHAUST LINE - Google Patents

Abstract

This device is of the type including an exhaust gas treatment member (4) comprising an envelope (10) having a first open end (18) and a second open end, and a conduit for guiding the exhaust gas between the first end open (18) and an orifice (32) of the conduit.La pipe is defined by at least two shells disposed on either side of the casing (10) of the exhaust gas treatment member (4), the shells defining between them a cavity (36) in which opens the first open end (18) .The orifice (32) is delimited by at least one shell and the shells delimit with the outer surface (38) of the casing (10) a passage extending along the casing (10) between the first open end (18) and the orifice (32) .Application to catalytic converters or particulate filters.

Description

The present invention relates to a gas treatment device

  exhaust system for a motor vehicle, of the type including:

  an exhaust gas treatment unit comprising an envelope internally delimiting a chamber receiving exhaust gas treatment means, the envelope having a first open end and a second open end; and at least one first pipe for guiding the exhaust gases between the first open end and an orifice of the first pipe.

  An exhaust line of an internal combustion engine motor vehicle generally comprises one or more exhaust gas treatment members for treating the exhaust gases prior to being exhausted to the outside.

  Different types of exhaust gas treatment members are known. Non-limiting examples are catalytic converters or particulate filters.

  The exhaust gas treatment members are connected together and at the output of the internal combustion engine by pipes.

  For reasons relating to the proper functioning of the current exhaust gas treatment members, it is desirable to implant these bodies in the exhaust line near the internal combustion engine. Indeed, this allows a faster temperature rise during a start-up phase and a higher temperature operation during a stabilized operating phase, because of the high temperature of the exhaust gas at the outlet of the engine. internal combustion.

  Nevertheless, the vehicles comprise motor housings already receiving a large number of vehicle equipment, such as a clutch, a braking master cylinder, a transmission bridge, a gearbox, etc. The space available for The implementation of the exhaust gas treatment unit is therefore reduced.

  However, the pipes with curved sections at the inlet or outlet of the exhaust gas treatment members have a large size because of their radius of curvature, which can hardly be reduced.

  An object of the present invention is to provide a compact exhaust treatment device and wherein the exhaust gas is deflected at the inlet or outlet of an exhaust gas treatment member.

  For this purpose, the invention proposes an exhaust gas treatment device of the aforementioned type, characterized in that the first pipe is defined by at least two shells arranged on either side of the casing of the pipe. exhaust gas treatment member, the shells surrounding the casing at least partially at the first open end, the shells define between them a cavity into which opens the first open end, and the orifice is delimited by at least a shell and is located on the side of the casing and the shells delimit with the outer surface of the casing a passage extending along the outer surface of the casing between the first open end and the orifice.

  According to other embodiments, the exhaust gas treatment device comprises one or more of the following characteristics, taken in isolation or in any technically possible combination: the orifice opens into the cavity in the direction of the outer surface of the envelope; an opening is defined between the connecting edges of the shells with one another, and the exhaust gas treatment member protrudes into the cavity through this opening; the orifice is defined between binding edges of the shells between them; the shells are substantially symmetrical to each other with respect to a binding plane of the shells; the shells are metallic and are made by stamping; the shells are metallic and fixed to one another by welding along a joint; the shells are fixed on the exhaust gas treatment member by welding between the outer surface of the exhaust gas treatment member and the periphery of the opening; the device comprises a second gas guide duct between the second open end and an orifice of the second duct, the orifice of the second duct being oriented in a direction making an angle of between approximately 0 and 90 with the direction of the second duct; orientation of the orifice of the first conduit.

  The invention also relates to an exhaust line comprising an exhaust gas treatment device as defined above.

  The invention and its advantages will be better understood on studying the description which will follow, given solely by way of example, and with reference to the appended drawings, in which: FIG. 1 is an exploded perspective view representing an exhaust gas treatment device according to the invention before assembly; - Figure 2 is a view similar to Figure 1 after assembly; Figure 3 is a sectional view along III-III of the device of Figure 2; - Figure 4 is a sectional view along IV-IV of the device of Figure 2; and FIGS. 5 and 6 are similar to FIG. 4 and illustrate first and second variants of the treatment device.

  In FIG. 1, an exhaust gas treatment device 2 forms a section of an exhaust line situated at the outlet of an internal combustion engine (not shown).

  The treatment device 2 comprises an exhaust gas treatment unit 4 and first 6 and second 8 shells able to form, when they are joined, a pipe for connecting the exhaust gas treatment unit. 4 in the exhaust line.

  The exhaust gas treatment unit is in the example illustrated a converter 4 of the catalytic type.

  The converter 4 has a metal casing 10 defining internally a chamber 11 receiving means for treating the exhaust gas. The casing 10 is cylindrical tubular and extends along an axis L. The processing means comprise a honeycomb structure 12 having a plurality of cells 14 with hexagonal section. Alternatively, the cells 14 have a different section, for example a quadrangular section.

  The internal surfaces of the cells 14 are coated with non-visible catalytic materials containing for example precious metals.

  The casing 10 has a first open end 18 and a second open end 20 allowing the entry and exit of the exhaust gases into the chamber 11 for passage through the cells 14.

  The second open end 20 opens into a cone 22 converging on the opposite side to the converter 4. The cone forms a connection line of the converter 4 in the exhaust line at its second open end.

  As shown in Figure 1, the shells 6, 8 are located on either side of the converter 4, at a distance thereof transverse to the axis L. The shells 6, 8 are intended to be close to the one of the other, as illustrated by the arrows A, so as to be brought into contact on opposite sides of the converter 4 and to be mutually secured by partially surrounding the converter 4.

  For their mutual attachment, the shells 6, 8 have connecting edges 24 intended to be in contact.

  Each edge 24 has a first cutout 26 formed recessed from the edge 24 and located opposite the first cutout 26 corresponding to the other edge 24. When the shells 6, 8 are joined, an opening 28 (Figure 2) is defined between the edges 24 by the first cutouts 26.

  Each edge 24 has a second cutout 30 formed recessed from the edge 24 and located opposite the corresponding second cutout 30 of the other edge 24. When the shells 6, 8 are joined, an orifice 32 (FIG. 2) is defined. between the edges 24 by the second cutouts 30.

  As illustrated in FIG. 1, the shells 6, 8 are advantageously symmetrical to one another with respect to a connection plane P (FIG. 2) of the shells 6, 8 passing through their edges 24.

  In a variant where the shells are not symmetrical, the orifice 32 is not defined between the edges 24 of the shells but is formed in one of the shells 6, 8 at a distance from its periphery. As can be seen in FIG. the shells 6, 8 once joined are in contact by their edges 26 along a seal 34 inscribed in the plane P which is radial with respect to the axis L. In a variant where the shells 6, 8 are not completely symmetrical, the edges 26 are provided with complementary reliefs interposing each other, so that the seal 34 is left.

  The shells 6, 8 together define between them an inner cavity 36 open towards the outside through the orifice 32 and the opening 28.

  The converter 4 is partly received in the cavity 36 through the opening 28.

  More specifically, the first open end 18 projects into the cavity 36 through the opening 28 so that it opens into the cavity 36 at a distance from the opening 28. The periphery of the opening 28 matches the contour of the outer surface 37 of the envelope 10. The converter 4 is set between the shells 6, 8 in the opening 28.

  A zone 38 of the outer surface 37 of the envelope 10 adjacent to the first open end 18 and located therebetween and the opening 28, is covered by the shells 6, 8. A remaining zone 39 of the outer surface 38 of the envelope 10 is discovered.

  The orifice 32 is located on the side of the converter 4, away from the open end 18 and also away from the open end 20. The orifice 32 is, relative to the plane of the first open end 8, the same side as the converter 4.

  Moreover, the orifice 32 opens towards the outer surface 38.

  The shells 6, 8 are for example metallic. Such shells are easily obtained by stamping.

  The assembly of the shells 6, 8 is easily made by placing them on either side of the converter 4. Due to the formation of the opening 28 by the meeting of the shells 6, 8, the latter are easily arranged around the converter 4 without the need for alignment and introduction of the converter 4 into the opening 28.

  The fixing of the shells 6, 8 between them and on the converter 4 is carried out easily, for example by welding the shells 6, 8 between them along the joint 34 and by welding the edges 24 with the outer surface 37 the envelope 10 to level of the first cutouts 26 delimiting the opening 28 As can be seen more clearly in FIG. 3, the shells 6, 8 delimit the cavity 36 having dimensions in a plane transverse to the axis L greater than those of the converter 4. It As a result, a passage 40 is defined between the outer surface 37 of the casing 10 and an inner wall 41 of the shells 6, 8.

  More specifically, the converter 4 is offset in the cavity 36 so that, on the side of the axis L opposite the orifice 32, the shells 6, 8 are substantially adjacent to the outer surface 37 of the envelope 10, and on the side of the orifice 32, the shells 6, 8 are spaced from the outer surface 37 of the envelope 10.

  As can be seen more clearly in FIG. 4, the passage 40 extends between the first open end 18 and the orifice 32, here parallel to the axis L. The shells 6, 8 form opposite the first open end 18 a curved wall 42 providing a space in the cavity 36 in front of the first open end 18.

  The passage 40 is defined in part between the zone 38 of the outer surface 37 of the envelope 10 and the shells 6, 8, and partly between the shells 6, 8 and the open end 18.

  The orifice 32 has a section of area less than that of the open end 18. To promote the flow of exhaust gas in the passage 40 to the open end 18 with a distribution of the exhaust gas on the the whole of the open end 18, the shells 6, 8 have walls diverging substantially from the orifice 32. The section of the passage 40 is gradually increasing from the orifice 32 to the open end 18.

  The orifice 32 is intended to be connected to a pipe of the exhaust line. Preferably, the orifice 32 is connected to the exhaust manifold of an unrepresented internal combustion engine.

  In operation, exhaust gases enter cavity 36 through port 32 having a main flow direction D1.

  The exhaust gases circulate in the passage 40 towards the first open end 18. The exhaust gases are deflected and penetrate into the first open end 18 with a main direction of flow D2 different from D1, and which is here perpendicular to dl.

  The gases then circulate in the chamber 11 where reactions occur with the catalysts internally covering the cells so as to eliminate or at least reduce the amount of harmful components in the exhaust gas.

  The exhaust gases from the engine are hot and flow in the passage 40 along the outer surface 37 of the envelope 10. This allows to bring heat to the envelope 10. It results in a rise faster temperature converter 4 in the start phase and a better maintenance of the operating temperature of the converter 4 in the stabilized operating phase.

  The orifice 32 oriented towards the surface 37 ensures satisfactory watering of the outer surface 37 by the gases, thus improving the heat exchange between the gases and the converter 4.

  The passage 40 being delimited in part by the converter 4, it follows that the device 2 as a whole is compact. The shells 6, 8 surrounding the converter 4 have a limited space in a plane transverse to the axis L and along the axis L. Alternatively or optionally, the exhaust gas treatment device 2 comprises shells replacing the cone 22 and defining an outlet pipe of the exhaust gas.

  In the example shown, the cone 22 has, on the opposite side to the second open end 20, an orifice 44 oriented along the axis L. This orifice 44 is oriented in a direction making an angle of about 90 with the direction D1 of the orifice 32 of the shells 6, 8.

  In the variant illustrated in FIG. 5, the cone 22 is of the oriented type, that is to say it comprises an orifice 44 oriented along an axis S inclined with respect to the axis L, and making an angle of about 45 with the direction D1 of the orifice 32 of the shells 6, 8.

  In the variant illustrated in FIG. 6, the orifice 32 and the orifice 44 of the cone 22 are situated in the same plane M and are held together by means of a flange 46. The orifice 32 and the orifice 44 are oriented in parallel directions, thereby making an angle of about 0 between them.

  More generally, the angle between the orifice 44 and the orifice 32 is preferably between 0 and 90.

  The invention applies to all types of exhaust gas treatment members, such as and for example, catalytic converters, including three-way converters, or particulate filters.

Claims (9)

  1.- exhaust gas treatment device for a motor vehicle, of the type including: - an exhaust gas treatment member (4) comprising a casing (10) internally defining a chamber (11) receiving treatment means Exhaust gas (12, 14), the housing (10) having a first open end (18) and a second open end (20); and at least one first conduit (6, 8) for guiding exhaust gases between the first open end (18) and an orifice (32) of the first conduit; characterized in that: - the first pipe is defined by at least two shells (6, 8) arranged on either side of the casing (10) of the exhaust gas treatment unit (4), the shells (6, 8) surrounding the casing (10) at least partially at the first open end (18); - The shells (6, 8) define between them a cavity (36) into which opens the first open end (18); the orifice (32) is delimited by at least one shell (6, 8) and is situated on the side of the envelope (10); and - the shells (6, 8) delimit with the outer surface (37) of the casing (10) a passage (40) extending along the outer surface (37) of the casing (10) between the first open end (18) and the orifice (32).   2.- Device according to claim 1, characterized in that the orifice (32) opens into the cavity (36) towards the outer surface (37) of the casing (10).   3.- Device according to one of claims 1 and 2, characterized in that an opening (28) is defined between the edges (24) connecting the shells (6, 8) to each other, and in that exhaust gas treatment member (4) protrudes into the cavity (36) through this opening (28).   4.- Device according to any one of the preceding claims, 5 characterized in that the orifice (32) is defined between edges (24) connecting the shells (6, 8) between them.   5.- Device according to any one of the preceding claims, characterized in that the shells (6, 8) are substantially symmetrical to each other with respect to a plane (P) for connecting the shells (6, 8).   6.- Device according to any one of the preceding claims, characterized in that the shells (6, 8) are metallic and are made by stamping.   7.- Device according to any one of the preceding claims, characterized in that the shells (6, 8) are metallic and fixed to one another by welding along a seal (34).   8.- Device according to any one of the preceding claims, characterized in that the shells (6, 8) are fixed on the exhaust gas treatment member (4) by welding between the outer surface (37) of the exhaust gas treatment member (4) and the periphery of the opening (28).   9.- Device according to any one of the preceding claims, characterized in that it comprises a second conduit (22) for guiding the gas between the second open end (20) and an orifice (44) of the second pipe (22). , the orifice (44) of the second pipe (22) being oriented in a direction making an angle of between approximately 0 and 90 with the direction (D1) of orientation of the orifice (32) of the first pipe (6). , 8).   The exhaust line, characterized in that it comprises an exhaust gas treatment device according to any one of the preceding claims.