Vehicle exhaust system for exhaust gas recirculation

Abstract

This combustion gas exhaust system (13) of a heat engine (5) of a vehicle (15) comprises an exhaust hose (17) configured to be fluidly connected to the heat engine (5), a catalytic converter (9) fluidly connected to the exhaust hose (17), and a first pipeline (19) positioned at the outlet of the catalytic converter (9) and configured to guide a fraction of a gas flow purified by the catalytic converter (9) to the exterior of the vehicle (15), the exhaust system further comprising a second pipeline (21) positioned at the outlet of the catalytic converter (9) and configured to reinject into the heat engine (5) a second fraction of the flow of gas purified by the catalytic converter (9).

Description

[0001] DESCRIPTION

[0002] VEHICLE EXHAUST SYSTEM FOR EXHAUST GAS RECIRCULATION

[0003] Technical field

[0004] The present invention relates to an exhaust system of a motor vehicle with a heat engine.

[0005] In particular, the present invention relates to the addition of a pipeline in the exhaust system intended to reintroduce purified, hot gases into the vehicle engine in order to promote a faster and less polluting start of said engine.

[0006] The invention also relates to the integration of this new pipeline in the exhaust system, in particular using single or dual flow hoses.

[0007] In general, the invention applies to any exhaust system of a vehicle.

[0008] Prior arts

[0009] Figure 1 shows schematically an exhaust system 1 of a motor vehicle 3 with a heat engine according to the prior art.

[0010] The motor vehicle 3 with a heat engine comprises a heat engine 5 and a combustion gas exhaust system 1 of said heat engine 5.

[0011] The exhaust system 1 comprises an exhaust hose 7 configured to be fluidly connected to the heat engine 5, a catalytic converter 9 fluidly connected to the exhaust hose 7, and an expansion chamber 11 fluidly connected to the catalytic converter 9 and configured to guide the flow of gas purified by the catalytic converter 9 to the outside of the motor vehicle 3 with a heat engine.

[0012] The exhaust hose 7 is a flexible pipeline that guides exhaust gases from the heat engine 5, attached to the motor vehicle 3 with a heat engine, on the one hand, to the catalytic converters 9 and expansion converter 11 , attached to the motor vehicle 3 with a heat engine, on the other hand. Thus, when the heat engine 5 in operating mode vibrates, the exhaust hose 7 makes it possible to avoid any transmission of vibrations from the heat engine 5 to the catalytic converter 9, and therefore to avoid mechanical fatigue and deterioration of the exhaust system 1. The exhaust hose 7 must also be able to be positioned in a narrow space of the motor vehicle 3 with a heat engine, and must therefore be compact.

[0013] Moreover, one of the defects of the heat engines 5 is their high consumption at start-up, pending the complete heating of said heat engine 5. Description of the invention

[0014] It is therefore the aim of the present invention to overcome the aforementioned drawbacks and to provide a vehicle with less consumption and pollution, in particular by providing an exhaust system allowing rapid heating of the engine at the start while guaranteeing a minimum space requirements.

[0015] This invention relates to an exhaust system for combustion gases of a vehicle heat engine, comprising an exhaust hose configured to be fluidly connected to the heat engine, a catalytic converter fluidly connected to the exhaust hose, and a first pipeline positioned at the outlet of the catalytic converter and configured to guide a fraction of a flow of gas purified by the catalytic converter to the exterior of the vehicle, the exhaust system comprising a second pipeline positioned at the outlet of the catalytic converter and configured to reinject into the heat engine a second fraction of the flow of gas purified by the catalytic converter.

[0016] Thus, the second line makes it possible to reinject hot gases into the engine in order to heat said engine more quickly, allowing a nominal operating mode to be reached more quickly, and thus consumption and pollution to be reduced.

[0017] Advantageously, the exhaust hose comprises a first single-flow hose, the second pipeline comprising a second single-flow hose.

[0018] In one embodiment, the first single-flow hose comprises a stapled sleeve for containing a flow of gas, a sealed corrugated sleeve positioned around the stapled sleeve, a metal braid positioned around the corrugated sleeve, and a flange at each end configured to hold the stapled sleeve, the corrugated sleeve, and the metal braid together.

[0019] In a particular embodiment, the first and second single-flow hoses are positioned adjacent to each other, the second single-flow hose comprising a stapled sleeve for containing a flow of gas, a sealed corrugated sleeve positioned around the stapled sleeve, a metal braid positioned around the corrugated sleeve, and a flange at each end configured to hold the stapled sleeve, the corrugated sleeve, and the metal braid together.

[0020] In another embodiment, the second single-flow hose is positioned inside the first single-flow hose so that the exhaust hose is a dual-flow hose, intended to circulate in one direction a flow of gas from the heat engine and in the other direction a flow of purified gas to the heat engine, the second single-flow hose comprising a sealed corrugated sleeve and positioned in the duct formed by the stapled sleeve of the first single-flow hose. Advantageously, the exhaust system comprises a first rigid tube connecting the heat engine to the first single-flow hose and a second rigid tube connecting the first single-flow hose to the catalytic converter, the second pipeline comprising two elbows positioned at the ends of the second single-flow hose and passing respectively through the first rigid tube and the second rigid tube so as to position the second single-flow hose inside the first single-flow hose.

[0021] In a particular embodiment, the second single-flow hose has a longitudinal length equal to within 5% of the longitudinal length of the first single-flow hose, the second single-flow hose having a diameter between 1 .5 and 5 times smaller than the diameter of the first single-flow hose.

[0022] Advantageously, each stapled sleeve and corrugated sleeve mainly comprise a material comprising stainless steel, the flanges being made of metal and welded to the metal braid.

[0023] Advantageously, the first pipeline includes an expansion chamber configured to reduce exhaust system noise.

[0024] The invention also relates to a vehicle, for example a motor vehicle, comprising a heat engine and an exhaust system as defined above.

[0025] Brief description of the drawings

[0026] Other aims, characteristics and advantages of the invention will become apparent on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings wherein:

[0027] [Fig 1] already mentioned, is a schematic view of an exhaust system of a motor vehicle with a heat engine according to the state of the art;

[0028] [Fig 2] is a schematic view of a first embodiment of an exhaust system of a motor vehicle with a heat engine according to the invention;

[0029] [Fig 3] is a schematic view of an exhaust hose of an exhaust system according to Figure 2;

[0030] [Fig 4] is a schematic view of a second embodiment of an exhaust system of a motor vehicle with a heat engine according to the invention; and

[0031] [Fig 5] is a schematic view of an exhaust hose of an exhaust system according to Figure 4. Detailed description of at least one embodiment

[0032] Figure 2 shows schematically a first embodiment of an exhaust system 13 of a motor vehicle 15 with a heat engine according to the invention.

[0033] The motor vehicle 15 comprises a heat engine 5 and a combustion gas exhaust system 13 of said heat engine 5.

[0034] The exhaust system 13 comprises an exhaust hose 17 configured to be fluidly connected to the heat engine 5, a catalytic converter 9 fluidly connected to the exhaust hose 17, and a first pipeline 19 positioned at the outlet of the catalytic converter 9 and configured to guide a fraction of a gas flow purified by the catalytic converter 9 to the outside of the motor vehicle 15 with a heat engine, for example through an expansion chamber 1 1 included in the first pipeline 19.

[0035] The exhaust system 13 further comprises a second pipeline 21 positioned at the outlet of the catalytic converter 9 and configured to reinject into the heat engine 5 a second fraction of the gas flow purified by the catalytic converter 9. In particular, the exhaust system 13 comprises a bypass 23 at the outlet of the catalytic converter 9, the bypass 23 being a pipeline comprising an inlet fluidly connected to the catalytic converter 9, and two outlets connected respectively to the first pipeline 19 and to the second pipeline 21 .

[0036] Thus, the second pipeline 21 makes it possible to reinject hot gases into the heat engine 5 in order to heat said heat engine 5 more quickly, allowing a nominal operating mode to be reached more quickly, and thus consumption and pollution to be reduced.

[0037] Advantageously, the exhaust hose 17 comprises a first single-flow hose 25, and the second pipeline 19 also comprises a second single-flow hose 27.

[0038] In one embodiment, the first single-flow hose 25 has a length between 15 and 50 cm, preferably between 20 and 30 cm.

[0039] Figure 3 shows schematically an embodiment of the first single-flow hose 25 which comprises, for example, a stapled sleeve 29 intended to contain a flow of gas. The stapled sleeve 29 is for example made of stainless steel so as to be able to withstand the high temperatures of the exhaust gases.

[0040] A sleeve is an element of generally tubular shape.

[0041] The first single-flow hose 25 also comprises a corrugated sleeve 31 , sealed against exhaust gases and positioned around the stapled sleeve 29. This corrugated sleeve 31 comprises a wall whose structure is accordion-shaped. The corrugated sleeve 31 thus makes it possible to define the stiffness of the first single-flow hose 25 and to ensure sealing. The corrugated sleeve 31 is for example made of stainless steel so as to be able to withstand the high temperatures of the exhaust gases.

[0042] The first single-flow hose 25 further comprises a metal braid 33 positioned around the corrugated sleeve 31. The metal braid 33 performs the protective role to prevent external elements from being interposed in the corrugated sleeve 31 .

[0043] The first single-flow hose 25 also includes a flange 35 at each end 37 of said first single-flow hose 25, each flange 35 holding together the stapled sleeve 29, the corrugated sleeve 31 , and the metal braid 33. For example, each flange 35 is a metal ring welded to the metal braid 33 and which exerts radial pressure in order to hold together the components of the first single-flow hose 25.

[0044] In a particular embodiment as shown in Figure 2, the first and second singleflow hoses 25 and 27 are positioned adjacent to each other so as to optimise the space available for the first and second single-flow hoses 25 and 27. In this embodiment, the second single-flow hose 27 is similar to the first single-flow hose 25 and comprises a stapled sleeve 29 for containing a flow of gas, a sealed corrugated sleeve 31 positioned around the stapled sleeve 29, a metal braid 33 positioned around the corrugated sleeve 31 , and a flange 35 at each end 37 configured to hold the stapled sleeve 29, the corrugated sleeve 31 , and the metal braid 33 together.

[0045] Figure 4 shows another embodiment of an exhaust system 13. In this embodiment similar to that of Figure 2, the second single-flow hose 27 is not positioned adjacent to the first single-flow hose 25 but inside the first single-flow hose 25.

[0046] Thus, the exhaust hose 17 is a dual-flow hose, intended to circulate in one direction a flow of gas from the heat engine 5 via the first single-flow hose 25, and in the other direction a flow of purified gas to the heat engine 5 via the second singleflow hose 27. This embodiment is particularly advantageous because it makes it possible to greatly reduce the space taken up by the second single-flow hose.

[0047] Figure 5 shows schematically an embodiment of the exhaust hose 17 in this embodiment.

[0048] In particular, the first single-flow hose 25 is similar to the first single-flow hose 25 detailed previously, while the second single-flow hose 27 comprises only a sealed corrugated sleeve 31 B in order to limit the space taken up by the second single-flow hose 27. The second single-flow hose 27 is positioned in the duct 39 formed by the stapled sleeve 29 of the first single-flow hose 25, the stapled sleeve 29 allowing the corrugated sleeves 31 and 31 B of the first and second single-flow hoses 25 and 27 not to come into contact and deteriorate. Advantageously, the exhaust system 13 comprises a first rigid tube 41 connecting the heat engine 5 to the first single-flow hose 25 and a second rigid tube 43 connecting the first single-flow hose 25 to the catalytic converter 9, the second pipeline 21 comprising two elbows 45 positioned at the ends of the second single-flow hose 27 and passing respectively through the first rigid tube 41 and the second rigid tube 43 so as to position the second single-flow hose 27 inside the first single-flow hose 25.

[0049] In a particular embodiment, the second single-flow hose 27 has a longitudinal length equal to within 5% of the longitudinal length of the first single-flow hose 25, the second single-flow hose 27 having a diameter between 1 .5 and 10 times smaller than the diameter of the first single-flow hose 25.

Claims

CLAIMS1 . Combustion gas exhaust system (13) of a heat engine (5) of a vehicle (15), comprising an exhaust hose (17) configured to be fluidly connected to the heat engine (5), a catalytic converter (9) fluidly connected to the exhaust hose (17), and a first pipeline (19) positioned at the outlet of the catalytic converter (9) and configured to guide a fraction of a flow of gas purified by the catalytic converter (9) to the exterior of the vehicle (15), characterised in that it comprises a second pipeline (21 ) positioned at the outlet of the catalytic converter (9) and configured to reinject into the heat engine (5) a second fraction of the flow of gas purified by the catalytic converter (9).

2. System according to claim 1 , wherein the exhaust hose (17) comprises a first single-flow hose (25), the second pipeline (19) comprising a second single-flow hose (27).

3. System according to claim 2, wherein the first single-flow hose (25) comprises a stapled sleeve (29) for containing a flow of gas, a sealed corrugated sleeve (31 ) positioned around the stapled sleeve (29), a metal braid (33) positioned around the corrugated sleeve (31 ), and a flange (35) at each end configured to hold the stapled sleeve (29), the corrugated sleeve (31 ), and the metal braid (33) together.

4. System according to claim 3, wherein the first and second single-flow hoses (25; 27) are positioned adjacent to each other, the second single-flow hose (27) comprising a stapled sleeve (29) for containing a flow of gas, a sealed corrugated sleeve (31 ) positioned around the stapled sleeve (29), a metal braid (33) positioned around the corrugated sleeve (31 ), and a flange (35) at each end configured to hold the stapled sleeve (29), the corrugated sleeve (31 ), and the metal braid (33) together.

5. System according to one of claims 2 and 3, wherein the second singleflow hose (27) is positioned within the first single-flow hose (25) such that the exhaust hose (17) is a double-flow hose, intended to circulate in one direction a flow of gas from the heat engine (5) and in the other direction a flow of purified gas to the heat engine (5), the second single-flow hose (27) comprising a sealed corrugated sleeve (31 ) and positioned in the duct (39) formed by the stapled sleeve (29) of the first singleflow hose (25).

6. System according to claim 5, comprising a first rigid tube (41 ) connecting the heat engine (5) to the first single-flow hose (25) and a second rigid tube (43) connecting the first single-flow hose (25) to the catalytic converter (9), the secondpipeline (19) comprising two elbows (45) positioned at the ends of the second singleflow hose (27) and passing respectively through the first rigid tube (41 ) and the second rigid tube (43) so as to position the second single-flow hose (27) inside the first singleflow hose (25).

7. System according to any of claims 2 to 6, wherein the second single-flow hose (27) has a longitudinal length equal to within 5% of the longitudinal length of the first single-flow hose (25), the second single-flow hose (27) having a diameter between 1 .5 and 5 times smaller than the diameter of the first single-flow hose (25).

8. System according to any of claims 3 to 7, wherein each stapled sleeve (29) and corrugated sleeve (31 ) predominantly comprise a material comprising stainless steel, the flanges (35) being made of metal and welded to the metal braid (33).

9. System according to any of claims 1 to 8, wherein the first pipeline (19) comprises an expansion chamber (11 ) configured to reduce the noise of the exhaust system (13).1 0. Motor vehicle (15) comprising a heat engine (5) and an exhaust system (13) according to any of claims 1 to 9.

Images