Powertrain and catalytic converter insulation by vacuum

Abstract

The invention relates to a powertrain (10) comprising: - a combustion engine having at least one cylinder (11), - a turbocharger (20) comprising a compressor (21) and a turbine (22) mounted on a rotating shaft (23), and - an exhaust gas treatment device (30) comprising a catalyst (31) and a vacuum chamber (32). According to the invention, the compressor (21) produces a vacuum at its inlet by drawing air from the vacuum tube (41). The fluid connection between the vacuum tube (41) and the vacuum chamber (32) creates a vacuum in said chamber, which isolates the catalyst (31). [Figure for the abstract: Fig. 2]

Description

Title of the invention: Powertrain and catalytic converter isolation by vacuum technical field

[0001] The invention relates to the field of motor vehicles and in particular to the field of pollution control of internal combustion engines of the diesel or gasoline type. In particular, the invention relates to a powertrain and a vehicle comprising such a powertrain.

[0002] In particular, the powertrain includes a heat engine comprising in particular a turbocharger and an exhaust gas treatment device which is isolated through a vacuum chamber, the vacuum being generated by venturi effect by a vacuum tube fluidly connected to the turbocharger compressor. Previous technique

[0003] There is an advantage to thermally insulating an exhaust gas treatment device such as a catalytic converter in order to treat nitrogen oxides commonly known as NOx. Indeed, thermal insulation of a catalytic converter reduces the heating time of catalytic converters and makes them effective more quickly.

[0004] In this regard, it is known to create a vacuum between the catalytic converter and a casing surrounding the catalytic converter. The vacuum created in the casing thermally insulates the catalytic converter and allows it to reach operating temperature more quickly. The vacuum around the catalytic converter also reduces noise from the exhaust gases.

[0005] US documents 6,162,403 and US 6,203,764, which describe in particular a catalytic converter comprising a vacuum chamber created, during the manufacture of the catalytic converter, by the use of a vacuum welding technique.

[0006] However, the design of these catalytic pots including a design void is very expensive and does not allow for the recovery of any leaks from the catalytic pot.

[0007] Document FR 2 995 352 describes a technical solution for creating and maintaining a vacuum in the vacuum chamber of the catalytic converter using a venturi system connected to the fresh air supply duct of the intake manifold of the engine cylinder(s).

[0008] However, the inventors realized that such a system did not produce a vacuum efficient enough to ensure thorough and constant insulation of the catalytic converter during the engine's operating time.

[0009] The invention aims to overcome all of these drawbacks. Description of the invention

[0010] The invention aims to provide a sufficiently efficient and constant vacuum in the vacuum chamber of the exhaust gas treatment device while controlling the manufacturing costs of the powertrain.

[0011] The invention aims to optimize the efficiency of the exhaust gas treatment device and in particular to improve its heating time, to provide a constant vacuum, but also to reduce noise pollution.

[0012] To this end, the invention relates to a powertrain comprising: - a combustion engine having at least one cylinder, - a turbocharger comprising a compressor and a turbine mounted on a turbocharger rotation shaft, the compressor supplies fresh air to said cylinder while the turbine is fluidly connected to an outlet of said cylinder, the turbine receives and is driven in rotation by the exhaust gases from combustion, and - an exhaust gas treatment device which includes a catalyst, a vacuum chamber which is configured to thermally insulate the catalyst and means for producing the vacuum, the gas treatment device being fluidly connected to an outlet of the turbine and receiving the exhaust gases.

[0013] The invention is characterized in that the means for producing the vacuum comprise a vacuum tube which is fluidically connected, on the one hand, to the vacuum chamber, and on the other hand, to an inlet of the compressor through an air intake which is positioned coaxially to the rotation shaft of the turbocharger, the compressor producing a vacuum at its inlet by drawing air from the vacuum tube, the fluidic connection between the vacuum tube and the vacuum chamber then makes it possible to create a vacuum in said chamber which isolates the catalyst.

[0014] The inventors discovered, surprisingly, that at the turbocharger inlet, the compressor produces a stronger vacuum in a coaxial area of ​​the compressor's rotation shaft. Positioning the vacuum tube's air intake in this specific area allows for optimal vacuum in the vacuum chamber that isolates the catalytic converter. The vacuum produced is achieved by the Venturi effect and maintained throughout engine operation by the vacuum generated at the turbocharger inlet, this vacuum being transmitted to the vacuum chamber via the vacuum tube.

[0015] In some embodiments, the air intake can be positioned at a minimum distance of 10 mm from the compressor. This minimum distance prevents the vacuum tube from interfering with the normal operation of the compressor. presser.

[0016] In some embodiments, the powertrain may include means for positioning the vacuum tube so as to position the air intake outlet coaxially with the turbocharger's rotation shaft. These positioning means allow the air intake outlet to be maintained in an optimal position to produce the highest possible vacuum.

[0017] In some embodiments, the powertrain may include a fresh air supply duct that is fluidly connected to the turbocharger inlet, with the vacuum tube extending at least partially into the supply duct. Passing the vacuum tube through the fresh air supply duct minimizes the need for technical modifications to the powertrain. The vacuum generation means are thus integrated into the powertrain at a lower cost.

[0018] In some embodiments, the diameter of the vacuum tube may be smaller than the diameter of the fresh air supply duct.

[0019] In some embodiments, the positioning means may include spacers that are attached to the internal walls of the supply duct. The spacers allow the vacuum tube and the air intake to be held in a specific position during engine operation. This makes it possible to maintain a constant vacuum within the vacuum chamber during engine operation.

[0020] In some embodiments, the vacuum tube may enter the supply duct through an opening in the wall of the supply duct. The powertrain includes a connecting element which, at said opening, secures the vacuum tube to the wall of the supply duct and seals the supply duct. The connecting element maintains optimal operating efficiency of the powertrain while improving the service life of the assembly between the vacuum tube and the supply duct.

[0021] In embodiments, the joining member may include mechanical adjustment means which are configured to fix the vacuum tube on said wall and to adjust the tightness of the supply conduit at the opening.

[0022] In embodiments, the connecting member can position and maintain the air intake mouth away from the compressor.

[0023] The invention also relates to a vehicle comprising a powertrain conforming to the invention. Brief description of the drawings

[0024] Other features and advantages of the invention will become apparent from the following description. This description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:

[0025] [Fig. 1] is a schematic representation of a conforming powertrain of an embodiment of the invention, the powertrain comprising in particular a turbocharger.

[0026] [Fig.2] is a schematic representation of a vacuum tube positioned in inlet of a compressor of the turbocharger of the powertrain of the [Fig.1].

[0027] [Fig.3] is a schematic representation of the arrangement of the vacuum tube relative to the turbocharger according to an embodiment of the invention and in which the fresh air supply duct has a curved configuration.

[0028] [Fig.4] is a schematic representation of the arrangement of the vacuum tube by related to the turbocharger according to an embodiment of the invention and in which the fresh air supply duct has a straight configuration.

[0029] [Fig.5] is a schematic representation of means for positioning an air intake mouth of the conforming vacuum tube of the invention.

[0030] [Fig. 6] is a schematic representation of an embodiment of a cross-section of a conforming connecting element of the invention which ensures the passage of the vacuum tube into the fresh air supply duct of the cylinder. Description of embodiments

[0031] With reference to [Fig. 1], the invention relates to a powertrain 10, particularly for a land vehicle such as a motor vehicle. The invention also relates to a vehicle comprising this powertrain 10.

[0032] As illustrated in [Fig. 1], the powertrain 10 comprises a combustion engine having at least one cylinder 11. In the embodiment of [Fig. 1], the cylinder(s) 11 are supplied with fresh air by a fresh air manifold 12 and the exhaust gases of the cylinder(s) 11 are recovered at the outlet of the cylinder(s) 11 by an exhaust manifold 13. The exhaust manifold is fluidly connected at the outlet of said cylinder 11 and configured to discharge the exhaust gases from said cylinder 11.

[0033] As illustrated in [Fig. 1], the powertrain 10 comprises a turbocharger 20 including a compressor 21 and an expansion turbine 22. The compressor 21 and the expansion turbine 22 are mounted on the same rotating shaft 23 of the turbocharger 20. In this example, the compressor 21 supplies fresh air to the cylinder(s) 11 through the fresh air manifold 12. In particular, the powertrain 10 includes a fresh air supply duct 14 which is fluidly connected, through the compressor 21, to the fresh air manifold 12. In the example In Figures 3 and 4, the supply duct 14 is connected to an air intake cone 24 of the turbocharger 20. Here, the intake cone 24 is located at the inlet of the compressor 21. The turbine 22 is fluidly connected to an outlet of the cylinder 11 via the exhaust manifold 13. As a result, the turbine 22 receives and is driven into rotation by the exhaust gases from the combustion taking place in the cylinder 11.

[0034] As illustrated in [Fig. 1], the powertrain 10 also includes an exhaust gas treatment device 30 comprising a catalyst 31 and a vacuum chamber 32 configured to thermally insulate the catalyst 31. The treatment device 30 is fluidically connected, at one end, to the turbine outlet 22 by means of an exhaust duct 15. A second end 33 of the treatment device 30 opens into the atmosphere to vent the treated exhaust gases. The invention does not relate to the treatment of the exhaust gases but only to the insulation of the catalyst to optimize its operation.

[0035] The powertrain 10 further comprises vacuum production means 40, the gas treatment device 30 being fluidly connected to an outlet of the turbine 22 and receiving the exhaust gases.

[0036] As illustrated in Figures 1 to 4, the vacuum production means 40 comprise a vacuum tube 4L. One end of the vacuum tube 41 is fluidically connected to the vacuum chamber 32. The second end of the vacuum tube 41 consists of an air intake 42. Advantageously, the intake 42 is positioned at the inlet of the compressor 21 coaxially with the rotation shaft 23 of the turbocharger 20. Thus, as illustrated in Figures 2 to 4, the intake 42 and the rotation shaft 23 of the turbocharger 20 extend along the same axis AA. In these same figures, the intake 42 opens into the inlet cone 24 of the turbocharger 20.

[0037] As illustrated in Figures 3 and 4, the inventors have surprisingly discovered that the area of ​​the intake cone 24 where the greatest depression is found corresponds to an area at the inlet of the compressor 21 which extends around the axis AA which corresponds to the axis along which the rotation shaft 23 of the compressor 21 extends. This depression is materialized by curved lines 25 symbolizing the flow of air drawn in by the compressor 21.

[0038] The compressor 21 creates a vacuum at its inlet by drawing in air from the vacuum tube 41, as well as fresh air flowing through the fresh air supply duct 14. The fluid connection between the vacuum tube 41 and the vacuum chamber 32 creates a vacuum in said chamber, thus isolating the catalyst 31.

[0039] According to one embodiment of the invention, the air intake mouth 42 is positioned at least 10 mm away from the compressor 21.

[0040] According to the embodiments, the powertrain 10 which includes means for positioning 50 of the vacuum tube 41 in the intake cone 24 so as to position the air intake mouth 42 coaxially with the rotation shaft 23 of the turbocharger 20 but also to position this mouth 42 at a distance from the compressor conforming to the invention.

[0041] According to embodiments illustrated in Figures 1, 3, and 4, in order to position the outlet 42 coaxially with the rotation shaft 23 of the turbocharger 20, the vacuum tube 41 extends at least partially into the supply duct 14. Other configurations can be envisaged according to the invention, for example, using a two-way Y-connector at the intake cone 24, one channel to connect the supply duct 14 to the inlet of the turbocharger 20 and one channel to connect and position the vacuum tube 41. It is also possible to modify the intake cone 24 to allow the outlet 42 to be optimally positioned according to one embodiment of the invention. However, these configurations are more expensive than the embodiment described in this document.

[0042] In particular, according to the embodiments illustrated in Figures 3 and 4, the vacuum tube 41 extends partially into the fresh air intake duct 14. For this purpose, the diameter of the vacuum tube 41 is smaller than the diameter of the fresh air supply duct 14. In one particular embodiment, the positioning means 50 may include spacers 51 that are integral with the vacuum tube 41 and the walls of the supply duct 14. As illustrated in Figures 3 to 5, the positioning means 50 may include a ring 52 that clamps the vacuum tube 41. The vacuum tube 41 may be mounted to slide relative to the ring 52 or be integral with it. For example, the ring 52 can be welded to the vacuum tube 41. The spacers 51 are integral with the ring 52 and extend, in particular radially, towards a peripheral edge 53.

[0043] In this example, the peripheral edge 53 is annular in order to cooperate with the walls of the feed duct 14, which has a circular cross-section. However, depending on the configuration of the feed duct 14, the peripheral edge 53 can have different shapes. Furthermore, in order to ensure that the mouth 42 is held in the optimal position according to the invention, the peripheral edge 53 can be welded to the inner wall of the feed duct 14.

[0044] According to the embodiments illustrated in Figures 3 and 4, the vacuum tube 41 enters the supply conduit 14 through an opening 140 formed in the wall of the supply conduit 14. In this configuration, the motor- The propeller 10 may include a connecting element 60 which ensures, on the one hand, the attachment of the vacuum tube 41 to the wall of the supply conduit at the level of the opening 140. The connecting element 60 also ensures the sealing of the supply conduit 14 at the level of the opening 140.

[0045] According to a particular embodiment, the connecting member 60 may include mechanical adjustment means configured, on the one hand, to fix the vacuum tube 41 on the wall of the sealing conduit 14, and on the other hand, to adjust the sealing of the supply conduit 14 in particular at the opening 140.

[0046] For example, as illustrated in [Fig. 6], the connecting member 60 may include a threaded male end 61 that is integral with the outer wall of the fresh air supply duct 14. Advantageously, this end 61 may have an internal conical sleeve 62 against which a seal 63 made of elastic materials such as silicone or rubber can be pressed. The connecting member 60 may also include a threaded nut 64 complementary to the end 61. To facilitate understanding of [Fig. 6], the connecting member 60 is shown unassembled, while the vacuum tube 41 passes through the opening 140 and is positioned in the fresh air supply duct 14. The seal 63 and the nut 64 are shown threaded onto the vacuum tube 41 and ready to be assembled to the fitting 61 in order to ensure the sealing of the opening 140 and to secure the vacuum tube 41 to the fresh air supply duct 14.The seal 63, the nut 61 and the conical sleeve 62 can then be considered as mechanical adjustment means.

[0047] Advantageously, the connecting member 60 positions and maintains the air intake at a distance from the compressor 21 according to one embodiment of the invention. This mechanical fastening limits the play of the vacuum tube 41 relative to the supply duct 14 and helps to extend the service life of the powertrain 10.

[0048] Figure 3 illustrates a particular embodiment in which the fresh air supply duct 14 is bent near the intake cone 24. In this embodiment, the opening 140 is advantageously located at the bend of the supply duct 14. This particular arrangement allows the use of a vacuum tube 41 with a straight cross-section, which enters and extends into the supply duct 14. Positioning the opening 42 is then facilitated during the assembly of the powertrain 10.

[0049] Fig. 4 illustrates another embodiment, in which the fresh air supply duct 14 is straight as it approaches the intake cone 24 of the turbocharger 20. According to this configuration, the vacuum tube 41 includes an angled section inside the supply duct 14 in order to position the mouth 42 in the axis AA.

Claims

Demands

1. Powertrain (10) comprising: - an internal combustion engine having at least one cylinder (H), - a turbocharger (20) comprising a compressor (21) and a turbine (22) mounted on a rotating shaft (23) of the turbocharger (20), the compressor (21) supplying fresh air to said cylinder (11) while the turbine (22) is fluidly connected to an outlet of said cylinder (11), the turbine (22) receiving and being driven into rotation by the exhaust gases from the combustion, - an exhaust gas treatment device (30) comprising a catalyst (31), a vacuum chamber (32) configured to thermally insulate the catalyst (31) and vacuum generation means (40), the exhaust gas treatment device (30) being fluidly connected to an outlet of the turbine (22) and receiving the exhaust gases,characterized in that the vacuum production means (40) comprise a vacuum tube (41) which is fluidically connected, on the one hand, to the vacuum chamber (40), and on the other hand, to an inlet of the compressor (21) through an air intake (42) which is positioned coaxially to the rotation shaft (23) of the turbocharger (20), the compressor (21) producing a vacuum at its inlet by drawing air from the vacuum tube (41), the fluidic connection between the vacuum tube (41) and the vacuum chamber (32) makes it possible to create a vacuum in said chamber which isolates the catalyst (31).

2. Powertrain (10) according to claim 1, wherein the air intake mouth (42) is positioned at a minimum distance of 10 mm from the compressor (21).

3. Powertrain (10) according to any one of claims 1 and 2, comprising positioning means (50) for the vacuum tube (41) so as to position the air intake mouth (42) coaxially with the rotation shaft (23) of the turbocharger (20).

4. Powertrain (10) according to any one of claims 1 to 3, comprising a fresh air supply duct (14) which is connected fluidly with the turbocharger inlet (20), the vacuum tube (41) extending at least partly into the supply duct (14).

5. Powertrain (10) according to claim 4, wherein the diameter of the vacuum tube (41) is less than the diameter of the fresh air supply duct (14).

6. Powertrain (10) according to claims 3 and 4, wherein the positioning means (50) comprise spacers (51) which are integral with the internal walls of the supply conduit (14).

7. Powertrain (10) according to any one of claims 4 to 6, wherein the vacuum tube (41) enters the supply conduit (14) through an opening (140) provided in the wall of the supply conduit (14), the powertrain (10) comprising a connecting member (60) which ensures at the level of said opening (140), on the one hand, the fixing of the vacuum tube (41) to the wall of the supply conduit (14), and on the other hand, the sealing of the supply conduit (14).

8. Powertrain (10) according to claim 7, wherein the connecting member (60) includes mechanical adjustment means which are configured to fix the vacuum tube (41) on said wall and to adjust the sealing of the supply conduit (14) at the opening (140).

9. Powertrain (10) according to claims 2 and 7, wherein the connecting member (60) positions and maintains the air intake mouth (42) away from the compressor (21).

10. Vehicle comprising a powertrain (10) defined according to any one of claims 1 to 9.

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