EP3256705A1

EP3256705A1 - Turbocharged engine assembly having two exhaust ducts comprising a recirculation line

Info

Publication number: EP3256705A1
Application number: EP16705245.5A
Authority: EP
Inventors: Diego Rafael Veiga Pagliari; Arnaud Dupuis
Original assignee: PSA Automobiles SA
Current assignee: PSA Automobiles SA
Priority date: 2015-02-09
Filing date: 2016-01-29
Publication date: 2017-12-20
Also published as: WO2016128642A1

Abstract

The invention relates to an engine assembly comprising an exhaust system having a first exhaust duct via the turbine (2), a second discharge duct and a tapping (12) for a recirculation line. The first duct opens into a main pressure-relieving passage (4') via an inlet face of a turbine housing (2c) and the second duct opens via the inlet face (2a) of the housing (2c) into at least one internal branching portion (8) of the housing (2c) bypassing the main pressure-relieving passage (4'). The tapping of said at least one recirculation line is achieved in the turbine (2) on a tapping portion (8) of at least the main pressure relieving passage (4') or of said branching portion (8) via at least one tapping end (12).

Description

TURBOCOMPRESSED ENGINE ASSEMBLY WITH TWO EXHAUST DUCTS WITH RECIRCULATION LINE

The present invention relates to an engine assembly for a motor vehicle comprising an internal combustion engine, a recirculation line of the exhaust gas at the engine intake, an air intake system to an engine inlet and an exhaust system at an engine output. Engine turbocharging is provided by a turbine and a compressor, the turbine being integrated in the exhaust system and the compressor in the air intake system, the exhaust system comprising two exhaust pipes extended in the turbine by joining portions.

The exhaust system of such a motor assembly is connected to an output of the turbocharged engine, also called supercharged engine, for an exhaust gas exhaust from combustion in the engine, the engine being advantageously but not only a four-stroke gasoline engine.

[0003] FIG. 1 shows a supercharged gasoline engine assembly according to the closest prior art described in particular in the document WO-A-2009/105463. Such an engine assembly is known under the name VEMB, abbreviation of the English name of "Valve Event Modulated Boost", translated into French by supercharging controlled by motor distribution. This type of engine assembly will be detailed after the general presentation of a conventional supercharged engine and an engine equipped with an exhaust gas recirculation line at the engine intake, also called EGR line.

Referring to Figure 1 for a portion of the elements illustrated in this figure, a thermal combustion engine comprises a cylinder block provided with at least one cylinder, preferably several cylinders and an air intake inlet or an air intake manifold for the gasoline air mixture in each cylinder and an exhaust gas outlet resulting from the combustion of the mixture in each cylinder. The output of the engine is connected to an exhaust manifold 5 supplying an exhaust duct 4, 9 exhausting the exhaust gases to the outside.

The fact that two exhaust manifolds 5, 7 each with an associated exhaust duct 4, 6 are shown for the engine assembly in Figure 1 is not applicable to any turbocharged engine assembly, such a motor generally comprising only a single manifold 5 and a single exhaust pipe 4, 9 extended inside the turbine 2.

The turbocharged engine comprises a turbine 2 and a compressor 3. The turbine 2 is disposed downstream of the exhaust manifold 5 in the exhaust pipe 4 while the compressor 3 is disposed upstream of the intake manifold. to the engine. The turbine 2 comprises a turbine wheel recovering at least partially a kinetic energy created in the exhaust gas passing therethrough, the rotary member or wheel of the turbine being rotated by the exhaust gases leaving the exhaust manifold . The turbine 2 drives the compressor 3 by being secured to it by an axis, the compressor 3 is traversed by fresh air for supplying air to the engine, air compressor 3 compresses.

At the outlet of the compressor 3, the air which is then called supercharging air is supplied by the air supply line to a charge air cooler 25 to cool the air leaving the compressor 3. On this line is also positioned a butterfly valve 26 regulating the flow of air into the air intake manifold of the motor forming the engine air inlet.

On the exhaust side of the engine assembly 1, at the outlet of the turbine 2, the exhaust gas exhausted from the engine enters the exhaust duct 9 of the motor vehicle after passing through the turbine 2 and Through exhaust gas removal means, for example one or more catalysts, in particular oxidation, reduction or three-way, associated or not with a particulate filter. A selective catalytic reduction system or RCS system may also be provided in the exhaust duct 9. [0009] It is also common to provide an engine assembly with an exhaust gas recirculation line at the intake of engine air, also called EGR line, such a line being referenced 1 1 in Figure 1. It is indeed known for spark ignition and compression ignition engines to recirculate the exhaust gases to the engine air intake to reduce nitrogen oxide emissions. Such a system is also known by the Anglo-Saxon acronym EGR for "Exhaust Gas Recirculation" which means Recirculation of Exhaust Gas.

An EGR line 1 1 has a stitching on the exhaust duct to withdraw a portion of the exhaust gas from the duct and a cooler 23 of the exhaust gas passing through this line 1 1, these gases are then very hot. The line RGE 1 1 opens on the intake of air upstream of the compressor 3 it feeds. A valve 24 called EGR valve equips the line RGE 1 1, advantageously downstream of the cooler 23, to open or close the flow of gas to the inlet. [001 1] For any type of line EGR 1 1, the recirculation of the exhaust gas to the air intake of the engine improves the engine thermodynamic efficiency due to the reduction of heat transfer through the reintroduction of recycled gases through line EGR 1 1 in the intake manifold. Such recirculation may also allow a decrease in the enrichment related to the exhaust temperature and a decrease in pump losses when the engine is associated with a turbocharger.

With regard to the reduction of losses by pumping, this was not entirely satisfactory and the pumping phenomena still persist in the turbine 2. It has been proposed to use a relief valve inside the pump. the turbine. It was then proposed an exhaust system for a motor supercharging engine controlled by two exhaust ducts engine distribution as shown in Figure 1.

The thermal combustion engine forming part of the set 1 said supercharging controlled by engine distribution has at least one cylinder, in Figure 1 three cylinders. Each engine cylinder is equipped with an intake valve and two exhaust valves. These exhaust valves may be selectively associated with a first or second exit passage in a cylinder and selectively open and close their associated passage.

It is the same for the intake valve associated with an inlet passage in each cylinder. The two outlet passages of each cylinder which are closed and opened sequentially by their associated exhaust valve open on a different exhaust manifold 5, 7 each supplying a dedicated exhaust duct 4, 6, the two ducts 4, 6 exhaust does not follow the same course as will be detailed below. The first exhaust passage of each cylinder is connected to the first manifold 5 and the second exhaust passage is connected to the second manifold 7.

A motor assembly 1 said supercharging controlled by engine distribution therefore comprises a first duct 4 said exhaust turbine 2 starting from a first exhaust manifold 5 and a second discharge duct 6 from a second exhaust manifold 7, the exhaust manifolds 5, 7 each being connected to one of the two sets of first or second exhaust passages respectively; equipped with their exhaust valves provided for each cylinder. The first conduit 4 leads to an inlet face of the turbine 2 of the turbocharger being extended by a main expansion channel inside the turbine 2 housing a turbine wheel to recover the kinetic energy content. in the exhaust gas passing through it. The second duct 6 bypasses the turbine 2 without entering but joins further downstream of the turbine 2 a third duct 9 connected to an outlet face of the turbine 2 for exhaust gas evacuation of the main flash passage having been in exchange for energy with the turbine wheel so that there is only one exhaust duct 9 passing through decontamination elements 10 placed at the end of the exhaust system. It follows that, in such a motor-controlled supercharging engine assembly according to the state of the art, the second duct 6 has no penetrating extension in the turbine 2.

The function of the first duct 4 said exhaust duct turbine is to allow a first flow of exhaust gas through the turbine 2 and its rotary energy recovery member in the form of a wheel to provide the power to the compressor 3. The function of the second duct 6, said discharge duct and fed by a second exhaust manifold 7, different and independent of the first exhaust manifold 5 of the first duct 4, is to allow a second flow of independent exhaust gas and different from the first flow to circumvent the turbine 2 and in particular its wheel and thus discharge the turbine 2 of the total flow of exhaust gas by decreasing the flow of exhaust gas therethrough by subtraction of the second stream to the total flow.

This makes it possible to discharge and / or control the power of the turbine, as would in a conventional operating condition of regulating the motor load a discharge valve, a previously known element of the state of the art for a turbocharged engine. . This makes it possible in particular to avoid the pumping phenomenon of the engine consisting essentially of a return of the hot gases to the intake air inlet.

For a conventional turbocharged engine, a discharge valve which may be internal or external to the turbine serves to limit the pressure of the exhaust gas on the turbine wheel of the turbocharger by opening a bypass of the exhaust gas. so that they no longer pass through the turbine and its wheel. A limitation of the speed of the wheel of the turbine is thus obtained, which also limits the speed of rotation of the wheel provided in the compressor being integral with the wheel of the turbine, which also limits the compression of the turbine. intake air. A relief valve associated with a turbine for the regulation of the flow of exhaust gas therethrough is no longer necessary with a motor-controlled supercharging engine assembly having two exhaust ducts each leaving a collector respective exhaust.

Thus, such an engine assembly improves the efficiency of the engine cycle by reducing the engine pumping during the exhaust phase of a four-stroke cycle, which has a favorable impact on the engine consumption. . Better control of the energy recovered by the turbine is therefore performed, which implies better management of the engine load.

In such a motor assembly, it can simultaneously coexist a high pressure RGE 1 1 recirculation line which can be stitched for example on the second discharge duct 6 and a low pressure recirculation line 1 1 which can be stitched for example on the first exhaust duct 4 per turbine, this advantageously downstream of the turbine 2. It may also exist only one recirculation line RGE 1 1 stitched on one of the two ducts 4, 6. a major drawback of the combination of an EGR line with a two-exhaust engine assembly starting from a respective exhaust valve of two exhaust valves per cylinder is that the connection of the line RGE 1 1 on the exhaust front of such an engine assembly can be complex. In addition, in low-pressure connection configuration for the EGR line, if the counterpressure of the exhaust outlet of the turbine 2 is not high enough, the flow capacity of the EGR line to the circuit of air intake of the engine is reduced, this especially in situations of low engine speed and / or low engine load. Thus, the maximum level of flow of the EGR line acceptable by the engine is no longer achievable, which limits the efficiency of the recirculation of the exhaust gas to the air intake. The patent application FR-A-2 992 353 describes a motor unit comprising a combustion engine with an exhaust system comprising a high pressure exhaust manifold supplying an exhaust line and a low exhaust manifold pressure feeding a recirculation line. The system also includes a gas tank which is connected to the engine by an isolation valve which can assume a communication configuration allowing a flow of gas between the engine and the tank and an insulation configuration preventing this circulation. This exhaust system is however complex with the presence of a reservoir and a conduit connecting it to the manifold, the valve being disposed in this conduit. Therefore, a problem underlying the invention is to improve a motor assembly said turbocharging engine controlled by two exhaust ducts, the supercharged engine being associated with a recirculation line of gas said exhaust line EGR, on the one hand, by reducing the complexity of the connection of the EGR line to the exhaust system of the engine assembly and, on the other hand, by obtaining that the operation of the EGR line is done optimal in all driving conditions of the motor vehicle.

To achieve this objective, there is provided according to the invention a motor assembly with an engine comprising at least one cylinder, at least one exhaust gas recirculation line at an engine intake, a turbocharger comprising a turbine and a compressor, and an exhaust system connected by a first and a second exhaust manifold to an engine outlet for exhaust gas exhaust from the combustion in the engine, the exhaust system comprising a first conduit said exhaust from the turbine leaving the first exhaust manifold and a second discharge duct from the second exhaust manifold, the turbine being provided with a casing having a main expansion passage in which is housed a wheel of turbine and the first duct opening into the main relief passage through an inlet face of the casing, characterized in that the second conduit opens through the this inlet of the housing in at least a portion of internal bypass to the casing bypassing the main relief passage and in that the stitching of said at least one recirculation line is in the turbine on a stitching portion of at least the expansion passage or said at least one branch portion via at least one stitching end.

The technical effect is to obtain at least one stitching end of at least one integrated recirculation line to the turbine, this through a housing surrounding the turbine. he it is thus possible to increase the rate of gas recirculation in connection condition as well low pressure or high pressure depending on whether the stitching is performed on the main flash passage or said at least one branch portion.

In addition, the fact of connecting the expansion passage and said at least one branch portion extending respectively the first or the second conduit in the turbine allows to maintain the same conventional system of aftertreatment of the exhaust gases of the engine than that preceding the improvement of a motor assembly by supercharging controlled by motor distribution.

Compared with a conventional turbocharger engine assembly, according to the present invention, a discharge valve is advantageously replaced by the branch portion or portions extending the second conduit within the turbine whose flow can easily be controlled. Even the stitching end opening into the recirculation line can be used for the discharge of the turbine, especially when the stitching end is formed on the expansion passage extending the first exhaust duct in the turbine. This is advantageously controlled by the engine control which has all the necessary parameters to determine whether a discharge of the impeller wheel is necessary or not.

Advantageously, the stitching portion on which the stitching is made via at least one stitching end is said at least one branch portion extending the second conduit and bypassing the wheel of the turbine, the exhaust system comprising a third conduit external to the turbine and connected to an outlet face of the turbine casing for exhaust gas discharge out of the turbine.

Advantageously, the stitching portion comprises at least one control valve for regulating at least one exhaust gas flow therethrough, said at least one control valve being operable between at least a first closed position. the flow rate in the stitching portion at or after said at least one stitching end and a second open stitching position in the stitching portion at or after said at least one stitching end.

Advantageously, the control valve is disposed towards at least one outlet end of said at least one nozzle portion at the outlet face of the turbine, intermediate opening positions of the control valve for adjusting the flow in said at least one tapping portion according to the degree of opening of the control valve corresponding to each respective intermediate position. [0034] Advantageously, the regulation valve is operable between at least four positions, namely:

a first closing position of said at least one stitching portion and at least one stitching end with a zero flow rate in said at least one stitching portion and in said at least one recirculation line,

a second position for closing said at least one stitching portion with a zero flow rate in said at least one stitching portion, the exhaust gases flowing entirely into said at least one recirculation line via said at least one end stitching,

a third position for closing said at least one recirculation line by closing said at least one stitching end with a zero flow rate in said at least one recirculation line, the exhaust gases in this stitching portion; flowing fully to said at least one outlet end of said at least one stitching portion,

fourth fourth positions of opening of said at least one stitching portion and said at least one recirculating stitching end, these intermediate opening positions making it possible to adjust the flow rate towards said at least one outlet end in said at least one minus a stitching portion and in said at least one recirculation line according to the degree of opening of said at least one stitching portion and said at least one stitching end corresponding to each respective intermediate position.

Advantageously, when the stitching portion is said at least one shunt portion, the control valve comprises a disk displaceable in translation or in rotation by an actuator, the disk bearing said at least one output end of said at least one a bypass portion and said at least one stitching end of said at least one recirculation line.

[0036] Advantageously, the disk of the regulating valve is either:

- I-shaped dish,

an inverted U-shaped section for which said at least one outlet end of said at least one branch portion is radially internal to the disk while said at least one stitching end is radially external to the disk, or of section in an inverted L shape for which said at least one output end of said at least one branch portion is axially internal to the disk while said at least one stitching end is radially external to the disk or said at least one an outlet end of said at least one branch portion is radially internal to the disk while said at least one stitching end is axially external to the disk.

Advantageously, the output disc is disposed around an outlet end of the first conduit, the output disc having an internal hollow recess vis-à-vis the outlet end of the first conduit.

Advantageously, said at least one outlet end of said at least one branch portion is of circular section, oval or half-moon shaped.

Advantageously, the casing of the turbine surrounds at a distance the wheel of the turbine and comprises an intermediate portion interconnecting its inlet face and an outlet face of the casing, the intermediate portion comprising at least one opening for said minus a stitching of said at least one recirculation line.

Furthermore, if we return to the description of Figure 1, it has been proposed to provide at least one of the conduits of a control valve. This control valve can make it possible to close or at least partially open its associated conduit and to increase the flow rate in the line RGE 1 1 when the tapping of the line 1 1 is disposed upstream of the control valve. However, as the exhaust gas is dirty and contain particulate soot, it is common that such a control valve clogs quickly and can no longer properly perform its function. The EGR valve 24 in the recirculation line 11 is also often faced with this problem.

For example, FR-A-2 902 465 recognizes this problem for a valve control valve undergoing fouling at the contact surface between the valve head and the valve seat. There may be a risk of sticking the valve head to its seat, which may prevent the valve from opening. On the other hand, the solution proposed in this document is to keep the same type of control valve by adding an anti-fouling device with a protective element isolating the exhaust valve stem, which only partially solves the problem. problem and complicates the structure of the control valve.

Therefore, an additional problem underlying the invention is to improve a motor assembly said turbocharged supercharging engine controlled by two exhaust ducts, the turbocharged engine being associated with at least one recirculation line of the engine. exhaust gas called RGE line stitched on at least one of exhaust ducts or, where appropriate, at least one extension of one of these ducts inside the turbine, ensuring that the operation of the EGR line is optimally performed in all driving conditions of the motor vehicle by means of regulating the flow in the line or the duct which is not conducive to fouling caused by the passage of the exhaust gases in its interior.

To also meet this additional problem, it is provided according to the invention a motor assembly, in particular as described above, comprising an internal combustion engine with at least one cylinder, a turbocharger comprising a turbine and a compressor, a an exhaust system connected to an engine outlet for exhausting exhaust gases from combustion in the engine and at least one exhaust gas recirculation line to an engine intake, the exhaust system comprising a first said exhaust duct by the turbine leaving a first exhaust manifold and a second duct said discharge from a second exhaust manifold, the turbine being provided with a casing having a main passage of relaxation in which is housed a turbine wheel and the first duct opening into the main relief passage through an inlet face of the housing, the recirculation line said at least one tapping portion on at least one tapping portion traversed by exhaust gases, characterized in that said at least one tapping portion comprises in its interior a device for regulating at least its flow, the control device extending along the inner wall of a portion of said at least one stitching portion leaving only a clearance sufficient for longitudinal movement of the device in said at least one stitching portion, the regulator being hollow and internally traversed by exhaust gases by having at least a first outlet exhaust side opening, the displacement being effected between a closed position for which said at least a first lateral opening of the device is not aligned with at least one outlet end of said at least one stitching portion and an open position for said at least one first lateral opening of the device is aligned with said at least one outlet end. The technical effect is to obtain a control device which has substantially the same section as the conduit in which it is inserted. When it is mentioned that the clearance between the part of said at least one stitching portion and the regulating device is only sufficient for a longitudinal displacement of the device in the part, it means that the regulating device has a section close to that of part of the stitching portion. A conventional control valve generally has a smaller passage area than the conduit on which it is installed. The passages inside the valve are therefore of reduced section and therefore liable to become fouled rapidly due to the particles contained in the exhaust gas. Unlike a conventional control valve, the control device according to the invention has an exhaust gas passage section only slightly lower than that of the duct in which it is integrated. The exhaust gas pressure on the outlet side opening is strong, which protects this opening from fouling.

Similarly, the flow of the exhaust gas in the control device is not disturbed or limited by the presence of the device elements housed in its interior as in a conventional control valve, for example the valve and its actuator for a valve control valve.

The opening or closing of the regulating device is by translation of the device itself and not an element housed in its interior. It follows that the displacement means of the regulating device, that is to say mainly its actuator, can be arranged outside the regulating device and are protected from fouling due to the passage of the gases. exhaust while, for a conventional control valve, the actuator is disposed inside the duct and undergoes a fouling that can disrupt its operation.

In one embodiment of the invention, such a control device can also be used if necessary as an exhaust gas recirculation line valve or replace it advantageously.

Advantageously, the second conduit opens through the inlet side of the casing in at least one internal bypass portion to the casing bypassing the main relief passage, the main expansion passage and said at least one branch portion joining at an outlet face of the casing, the exhaust system comprising a third duct outside the turbine connected to the outlet face of the turbine casing for exhaust gas discharge out of the turbine.

Advantageously, the displacement of the regulating device is controlled by an actuator external to the regulating device and stopping the movement of the device. control in intermediate opening positions for adjusting the output flow of said at least one stitching portion according to the degree of opening corresponding to each respective intermediate position. Advantageously, the regulating device comprises at least a second lateral outlet opening of the exhaust gas, the stitching of the recirculation line being effective on said at least one stitching portion when said at least one stitching end is aligned with said at least one second lateral opening of the device.

Advantageously, said at least one first and second lateral openings are positioned on the regulating device so that they are selectively positioned with respectively said at least one outlet end of the stitching portion or said at least one stitching end. .

Advantageously, said at least one first and second lateral openings are positioned on the regulating device so that when one of said at least one opening is aligned with at least one outlet end of the stitching portion or at least one a respective stitching end, the other of said at least one aperture is partially aligned with said at least one stitching or outlet end respectively leaving a reduced passage to the exhaust leaving the control device through the stitching end or respective output.

Advantageously, the portion of said at least one stitching portion receiving the regulating device and the regulating device are of cylindrical shape, said at least first and second lateral openings being disposed on the wall of the cylinder formed by the device. regulation.

Advantageously, the regulating device comprises a closing head capping a circular end portions of the cylinder formed by the regulating device, an actuator pressing the head for the displacement of the device.

Advantageously, the control device is positioned inside the turbine, the casing surrounding the turbine at a distance comprising an intermediate portion connecting the inlet and outlet faces to each other and the actuator has a through rod. the housing, one end of the rod pressing on the head while the other end is located outside the turbine. This has the major advantage that the actuator rod is not in contact with the exhaust gas because it is separated from them by the head. There is no risk of fouling of this rod, which is the major risk for many types of control valve.

Advantageously, a return spring is wound around the rod inside the housing, the spring reminding the control device in the position for which said at least one first lateral opening is aligned with said at least one end of output of said at least one stitching portion. Other features, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the accompanying drawings given by way of non-limiting examples and in which:

FIG. 1 is a schematic representation of a turbocharged engine assembly comprising an exhaust system with two exhaust ducts and an EGR line according to the closest state of the art,

FIG. 2 is a schematic representation of a turbocharged engine assembly comprising an exhaust system with two exhaust ducts and an EGR line according to the present invention, the turbine being traversed by extensions of the two ducts,

FIG. 3 is a diagrammatic representation in perspective of an embodiment of a turbine surrounded by its casing, this turbine forming part of the exhaust system according to the present invention and FIGS. 3a and 3b showing embodiments of the outlet face of the turbine through which the exhaust gases exit,

FIG. 4 shows a longitudinal section of a turbocharger, the turbine of the turbocharger being integrated into the exhaust system of the engine assembly according to the present invention, illustrating a first embodiment of a control valve for the portion bypass extending in the turbine the second conduit and FIG. 4a shows an outlet face of the turbine according to FIG. 4,

- Figure 5 shows a section of a turbocharger with the turbine provided with a control valve but according to another embodiment in Figure 4 and Figure 5a shows an outlet face of the turbine according to Figure 5 , this turbine forming part of the exhaust system of the engine unit according to the present invention,

- Figures 6, 6a to 6e show a control valve in the bypass portion extending the second duct inside the turbine respectively in various positions in the closed position and opening in the motor assembly according to the invention and this for two embodiments with or without stitching of the EGR line, FIG. 7 is a diagrammatic representation in perspective of another embodiment of a turbine provided with a control valve on an internal bypass portion,

FIGS. 8, 9 and 9a show a respective embodiment of a disc carrying outlet end openings of the branch and tipping end portion for an exhaust gas recirculation line, this disc may be part of a turbine element of the motor assembly according to the present invention,

FIG. 10 is a schematic representation of the turbocharged engine assembly shown in FIG. 1 with the presence of a regulating device, this assembly being able to conform to the present invention when at least one of the ducts is provided with a device as shown in FIGS. 4 to 6,

- Figure 1 1 is a schematic representation of a control device introduced into one of the two ducts of an exhaust system of an engine assembly according to the present invention, the control device being in this figure in the position of opening of the outlet end of the duct and closing of the stitching end located on the duct,

FIG. 12 is a schematic representation of a regulating device introduced into at least one of the two ducts, or in at least one of their extensions in the turbine, of an exhaust system of an engine assembly according to the present invention. invention, the control device being in this figure in the closed position of both the outlet end of the conduit and the stitching end located on the conduit,

FIG. 13 is a schematic representation of a regulating device introduced into one of the two ducts, or in at least one of their extensions in the turbine, of an exhaust system of an engine assembly according to the present invention, the regulating device being in this figure in the closed position of the outlet end of the conduit housing and opening of the stitching end located on the conduit.

It is to be borne in mind that the figures are given by way of examples and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate the understanding of the invention and are not necessarily at the scale of practical applications. In particular, the dimensions of the various elements illustrated are not representative of reality.

In what follows the words "downstream" and "upstream" are to be taken in the direction of the flow of exhaust gas out of the engine or again to the entrance of the engine for the recirculation line, an element in the exhaust system downstream of the engine being further away from the engine than another element upstream of the element. What is called the engine assembly includes the engine as well as its auxiliaries for the intake of air into the engine and for the exhaust of gases out of the engine, a turbocharger also forming part of the engine assembly, the turbine being included in the exhaust system of the engine assembly.

Figure 1 has already been described in the introductory part of this patent application.

Referring to all the figures except Figure 1 and in particular in Figure 2, there is shown an engine assembly according to the present invention which incorporates some of the characteristics of the engine assembly of the state of the art with, however, a different exhaust system.

The engine assembly 1 comprises an internal combustion engine and a turbocharger comprising a turbine 2 and a compressor 3. The turbine 2 comprises a wheel recovering at least partially the kinetic energy of the gases passing through it and transmits this energy to the compressor 3.

For this, the turbocharger is provided with an axis connecting the wheel of the turbine 2 to a wheel in the compressor 3 ensuring the compression of the air passing through the compressor 3. This axis can be lubricated, cooled by water and / or oil and installed on bearings with or without bearings. This axis may also be equipped with an electrical assistance, either directly on the axis, or with the help of gears, for example a transmission or a gearbox.

The exhaust system is connected to an output of the engine for an exhaust gas exhaust from combustion in the engine and comprises a first duct 4 said exhaust turbine 2 from a first collector 5 exhaust and a second duct 6 said discharge from a second exhaust manifold 7. The first and second manifolds 5, 7 are connected to the outlet of the internal combustion engine for the exhaust gas channeling through the first and second ducts 4, 6. The output of the engine can be constituted by two outlet passages per cylinder on the engine each associated with an exhaust valve but this is not limiting although this is illustrated in Figure 2. In FIG. 2, the engine comprises at least one cylinder having two outlet passages for evacuation of exhaust gases resulting from combustion in the engine, the first outlet passage being connected to the first collector 5 while the second outlet passage is connected to the second manifold 7. The present invention can also be applied to a motor with at least one cylinder having only one outlet passage, the first and second collectors 5, 7 being connected to this alone passage.

The two exhaust manifolds 5, 7 may be close to each other to be connected to the turbine 2, for example by the same exhaust manifold connection flange with a turbine casing 2c 2. The exhaust manifolds 5, 7 may be cooled by a cooling liquid, in particular water, the liquid circulating in a common cooling circuit or not common to the two collectors 5, 7. The cooling circuit or circuits may also to cool the inside of the turbine 2.

The turbine 2 is provided with a housing 2c surrounding it by having at least one input face 2a and 2b output face. The turbine 2 has a main relief passage 4 'in which is housed a turbine wheel and the first conduit 4 opens into the main passage of expansion 4' by the inlet face 2a of the housing 2c. The main relief passage 4 'is particularly visible in Figures 3, 4 and 5.

The exhaust system also comprises a stitching by a stitching end 12 on the second conduit 6 or its extension in the turbine 2 for a recirculation line 1 1 of the exhaust gas at the engine intake. This tapping may also be on the first conduit 4 or its extension in the turbine 2 in replacement or in association with the tapping on the second conduit 6.

According to the present invention, the second duct 6 opens through the inlet face 2a of the casing 2c in at least one branch portion 8 internal to the casing 2c bypassing the main relief passage 4 'and the stitching of said at least one recirculation line 1 1 is made in the turbine 2 on a stitching portion 8 of at least the expansion passage 4 'or said bypass portion 8 via at least one stitching end 12. [0071] Thus, a Bypass portion 8 extending the second duct 6 inside the turbine 2 is integrated in the turbine 2 but is not in exchange for kinetic energy with the turbine wheel, which provides a discharge effect of the turbine. turbine even more efficient than the discharge effect obtained with a relief valve. In addition, the fact that a bypass portion 8 extending the second conduit 6 inside the turbine 2 is integrated in the turbine 2 reduces the size of the exhaust system and reduces the expense of material for the ducts 4, 6, the junction of the first and second ducts 4, 6 being in the turbine 2 and not after the turbine 2, resulting in a shortening of the length of the second duct 6.

According to the invention, the stitching of the recirculating line RGE 1 1 is done on at least a portion 8 of one of the first and second conduits 4, 6 internal to the turbine 2 via at least one end of stitching 12 said portion 8 advantageously comprising a regulating valve 13, 13a for the regulation of at least one flow of exhaust gas passing therethrough. If in Figure 2 the stitching portion is the branch portion 8 extending the second conduit 6 inside the turbine 2, this is not necessarily the case within the scope of the invention.

Thus, it can be obtained a line RGE 1 1 high pressure, in which case it is in the extension of the second duct 6 said discharge by at least one branch portion 8 not passing through the wheel of the turbine 2 that the stitching is done.

It can also be obtained a line RGE 1 1 low pressure, in which case it is in the extension of the first duct 4 said exhaust through the main passage of expansion 4 'inside the turbine 2 that the stitching is done. It is also possible to cumulate the taps both on the respective extensions 4 ', 8 in the turbine 2 of the first duct 4 and second duct 6 which are respectively the main passage of expansion 4' and said at least one branch portion, in which case lines RGE 1 1 high and low pressures are obtained, these lines being stitched inside the turbine 2.

Preferably, the portion or portions on which the stitching via at least one stitching end 12 is one or more bypass portions 8 of the second duct 6 bypassing the wheel of the turbine 2, this to obtain a line RGE 1 1 high pressure. This allows an optimization of the flow distribution initially passing through the second duct 6 with respect to the flow initially passing through the first duct 4, which allows better aerodynamics at the outlet of the turbine 2. In a first embodiment of the present invention, the control valve 13, 13a can be operable between at least a first position of closure of the flow in the branch portion or portions serving as a stitching portion 8 after stitching 12 and a second open position of the flow in the branch portion or portions 8 after stitching 12.

In this embodiment, it should be noted, on the one hand, that there may be several branch portions that are stitched. On the other hand, if in the figures the control valve 13, 13a is integrated in a bypass portion 8, this is not limiting, such a control valve can be integrated in the main relief passage 4 'in association with or replacing a tapping in the branch portion or portions. This is also valid for the second embodiment which will now be detailed. In a second embodiment of the invention, which is preferred to the first mentioned, the control valve 13, 13a may be arranged towards the outlet end or ends 8b of the at least one branch portion 8 tapping portions on the outlet face 2b of the turbine 2, intermediate opening positions of the control valve 13, 13a can be used to adjust the flow in the branch portion or portions 8 according to its corresponding degree of opening at each respective intermediate position. There are therefore several degrees of opening possible with consequently obtaining a modulation of the output flow of the branch portion or portions 8 serving as stitching portions.

As shown in particular in Figures 3 and 7, the turbine 2 of the turbocharger can be integrated in a housing 2c having at least one inlet face 2a for the exhaust gas receiving the ends of the first and second conduits 4, 6 and an outlet face 2b for the exhaust gases leaving the turbine 2. The casing 2c may have a quilting outlet 12a passing through the turbine 2. In FIGS. 3, 4a, 5a and 7, the inlet end is shown 8a and the outlet end 8b of a bypass portion 8. FIG. 3a shows an outlet face of the casing with a single outlet end 8b of a bypass portion while FIG. 3b shows a face the outlet end of the casing with several outlet ends 8b of a branch portion, these outlet ends being adjacent to this figure but may also be distributed uniformly and concentrically on the outlet face of the casing. In a first embodiment of the non-limiting invention concerning the control valve, as shown in FIG. 4, the regulation valve 13 can only close the output end of the bypass portion 8 as portion of stitching to prevent the second flow through this branch portion 8 of lead to the exit face 2b of the housing 2c. In this embodiment, the control valve 13 does not control the closing or opening of the EGR line by its stitching end. FIGS. 4a and 5a illustrate an inlet face 2a of the casing of the turbine with the inlet opening of a main expansion passage 4 'and a bypass portion 8 respectively extending the first duct 4 or the second leads 6 in the turbine.

In a preferred embodiment of the invention concerning the control valve, the control valve 13, 13a may be arranged at the outlet end or ends 8b of the at least one branch portion 8 serving as portions of the control valve. stitching on the outlet face 2b of the turbine 2, the control valve 13, 13a being operable between at least four positions.

Figure 5, while referring to Figure 2 for some of the references, shows in particular three positions a, b, c of a control valve 13a. The first position, referenced c, may be a closing position of the output of said at least one branch portion 8 and of said at least one stitching end 12 with a zero flow in said at least one branch portion 8 and in said at least one RGE line 1 1 recirculation.

The second position, referenced b, may be a closed position of the output of said at least one branch portion 8 with a zero flow at the output of said at least one bypass portion 8, the exhaust gases of the second duct 6 flowing entirely in said at least one recirculating RGE line 1 1 via said at least one stitching end 12.

The third position, referenced a, may be an open position of the control valve 13a leaving open the outlet end 8b of the bypass portion 8 extending the second conduit 6 inside the turbine 2 opening towards the outlet face 2b of the turbine 2 and the stitching end 12, the flow of the second duct 6 being divided between a flow towards the outlet face 2b of the turbine 2 and a flow in the EGR line 1 1 for recirculation of the exhaust gas.

Another position may be a closed position of said at least one recirculating RGE line 1 1 by closing said at least one stitching end 12 with a zero flow rate in said at least one recirculating RGE line 1 1. , the exhaust gases flowing towards the outlet of said at least one branch portion 8 extending the second duct 6 inside the turbine 2 towards the outlet face 2b of the turbine 2. Finally, intermediate positions are possible by being partial opening positions of said at least one bypass portion 8 and said at least one recirculation tapping end 12, these intermediate opening positions to adjust the output flow of said at least one bypass portion 8 and in said at least one recirculation RGE line 1 1 according to the degree of opening of said at least one branch portion 8 and said at least one corresponding stitching end 12 at each respective intermediate position.

Thus, the control valve 13, 13a may, in some embodiments of the present invention, control the flow of the branch portion 8 and the line RGE 1 1 recirculation beginner of the stitching 12. There is therefore an economy of means obtained by these characteristics.

This is illustrated in particular in Figures 6 and 6a to 6e which show various positions of a control valve 13, according to the present invention, this respectively for a first embodiment in which the control valve 13 operates in the portion stitching 8 separating an upstream portion of the stitching portion of a downstream portion 8 'at the end of stitching portion 8 or respectively for a second embodiment in which the control valve 13 operates between, a on the one hand, an upstream part of the stitching portion 8 and the end of the stitching 12 and, on the other hand, the downstream part 8 'at the end of the stitching portion 8. [0091] These representations are schematic, the downstream part 8 at the end of the stitching portion 8 opening towards the outlet face of the casing of the turbine, the casing of the turbine and its outlet face not however being represented in these figures. In addition, as previously mentioned, the stitching portion 8 may be a bypass portion extending the second conduit or the main expansion passage extending the first conduit.

In these figures, the control valve 13 is in the form of a cone that can completely obstruct the end of the upstream portion of the stitching portion 8 and, where appropriate, the end of the stitching 12 of the EGR line. The control valve 13 can be moved by an actuator 15 to these figures by translation. It should be borne in mind that all these features are not limiting and that another arrangement of the EGR quilting and the quilting portion 8 and another form of control valve 13 can be adopted. In a first embodiment shown in FIGS. 6, 6a and 6b, the regulation valve 13 is displaceable in translation between a closed position and an open position of the end of the upstream portion of the portion of In the first case, the flow of the upstream portion of the stitching portion 8 does not result in the downstream portion 8 'at the end of the stitching portion 8 and in the second case, the flow of the upstream portion of the stitching portion 8 the stitching portion 8 terminates in the downstream part 8 'at the end of the stitching portion 8, its flow rate being adjustable by translation of the regulating valve 13, a progressive transverse widening of the downstream part 8' leading to a greater flow rate due to at a larger opening between the valve 13 and the walls of the downstream portion 8 '. In FIG. 6, the upstream part of the stitching portion 8 is closed by the regulation valve 13. No flow of exhaust gas coming from the upstream part of the stitching portion 8 ends up in the downstream part 8 'at the end of the stitching portion 8. In FIG. 6a, the regulating valve 13 has begun its translation towards the downstream part 8' at the end of the stitching portion 8 but still closes the upstream part of the stitching portion 8. In FIG. 6b, the control valve 13 has continued its translation, has reached the level of the transverse widening of the downstream part 8 'at the end of the stitching portion 8 and no longer closes the upstream portion of the portion of The flow therefore passes from the upstream portion of the stitching portion 8 into the downstream portion 8 'at the end of the stitching portion 8.

In a second embodiment shown in FIGS. 6c to 6e, the stitching end 12 and the upstream portion of the stitching portion 8 extend in parallel while being traversed by the exhaust gases in the opposite direction. compared to each other. The control valve 13 is interposed between, on the one hand, the stitching end 12 and the upstream part of the stitching portion 8 and, on the other hand, the downstream part 8 'at the end of the stitching portion 8. In FIG. 6c, the regulation valve 13 which is of conical shape has its tip adjacent to the edge of the separation duct between the stitching end 12 and the upstream part of the stitching portion 8. The upstream portion of the stitching portion 8 is closed by the control valve 13 and the stitching end 12 input. No flow of exhaust gas from the upstream portion of the stitching portion 8 thus leaves neither by the downstream portion 8 'at the end of stitching portion 8 nor by the stitching end 12 to feed the EGR line.

In FIG. 6d, the upstream part of the stitching portion 8 still does not communicate with the downstream part 8 'at the end of the stitching portion 8 because of the position of the regulation valve 13, although this made a translation taking off his tip from the edge the separation duct between the stitching end 12 and the stitching portion 8. The conical tip of the regulating valve 13 no longer closes the end of the inlet stitching 12 of the EGR line. The flow of exhaust gas from the upstream portion of the stitching portion 8 passes only through the stitching end 12 to feed the EGR line.

In FIG. 6e, the control valve 13 has continued its translation, has reached the level of the transverse widening of the downstream part 8 'and thus no longer closes the communication between the upstream part and the downstream part of the The flow thus passes from the upstream portion of the stitching portion 8 into the downstream portion 8 'but also through the stitching end 12. The flow of the exhaust gas from the second conduit is distributed between the downstream portion 8 'at the end of the stitching portion 8 and the EGR line through its stitching end 12 inlet. The flow rate in the downstream part 8 'at the end of the stitching portion 8 increases with the progression of the transverse widening of this downstream part. Figures 7, 8, 9 and 9a illustrate a control valve which is rotatable by an actuator 15. The casing 2c of the turbine 2 shown in Figure 7 is substantially the same as that shown in Figure 3 and differs from the latter only in a position different from the stitching end 12, this stitching end 12 not being visible in FIG. 7. The elements inside the casing 2c are also substantially similar except for the valve Regulation 13.

In these figures, the control valve 13 comprises a closure disc, referenced 29 in Figures 8, 9 and 9a, movable in rotation by an actuator 15. The shutter disc 29 carries the output end or ends 8b of the branch portion or portions 8 and the stitching end (s) 12 of the recirculation EGR line. The shutter disk 29 of the control valve 13 may be flat in the form of I. It may also be of inverted U-shape for which the outlet end or ends 8b of the at least one branch portion 8 are radial radial internal shutter disc 29 while the one or more tip ends 12 are radial external to the shutter disc 29. The shutter disc 29 may be of inverted L shape for which the outlet end or ends 8b of the at least one branch portion 8 is axially internal to the closure disk 29, while the stitching end or ends 12 are radially external to the closure disc 29 or the outlet end or ends 8b of the at least one branch portion 8 are radial internal to the shutter disc 29 while the one or more stitching ends 12 are axially external to the shutter disc 29. The shutter disk 29 receives at its inside a disk carrying the outlet ends 8b of the at least one branch portion. According to the rotation of the shutter disc 29, the exit ends 8b carried by the disc can be placed opposite the exit ends of the shutter disc 29 to ensure a passage of the flow either towards the exit face of the turbine or to the quilting ends 12 of the EGR line.

The closing disc 29 may also be disposed around the outlet end of the main expansion passage, referenced 4 'to Figure 7, the closure disc 29 having an inner hollow recess in vis-à-vis the output end 4b of the main expansion channel 4 'as shown in Figure 7 for these two references. With such a closure disc 29, the closures, the complete or partial openings of the outlet ends 8b are reached at the same time for all the exit ends, all the exit ends 8b simultaneously having the same degree of opening when the rotation of the shutter disc 29.

[00104] Referring to all the figures except Figure 1, the output ends 4b, 8b of the main channel of relaxation 4 'and said at least one branch portion 8 inside the casing 2c of the turbine 2 can lead to the same level of the turbine 2 to the outlet face 2b of the casing 2c of the turbine 2, that is to say upstream of this outlet face 2b in the turbine 2. The third conduit 9 which is external the casing 2c of the turbine has a mouth on the outlet face 2b of the casing 2c away from the turbine 2 starting from this outlet face 2b of the exhaust gas of the turbine 2. In a conventional manner, the third conduit 9 has elements 10 for removing pollution from the exhaust gas flowing through it.

As previously mentioned, the flow of exhaust gas passing through the casing 2c of the turbine by at least one branch portion 8 extending the second duct 4 said discharge may be subtracted from the total flow of exhaust gas out of the engine and only remains the flow of the first duct 4 said exhaust turbine passing through the main channel of relaxation 4 'housing the wheel of the turbine 2. This decreases the available power for the turbocharger and is substantially valve function Conventional discharge for turbocharger. In one embodiment of the engine assembly according to the present invention, the output of the engine comprises per cylinder two outlet passages closed by a respective exhaust valve, an outlet passage feeding the first duct 4 said d turbine exhaust and the other outlet passage feeding the second duct 6 said discharge via the collectors 5 and 7 exhaust. [00107] However, the opening of the exhaust valve connected to the second duct 6 occurs very often after the opening of the exhaust valve connected to the first duct 4 and still during the exhaust phase of the fourth cycle. engine time, even on the latest phasing of the opening of the exhaust valve connected to the second duct 6. There is thus a period of time for which the two exhaust valves are open at the same time, which makes the function of the second discharge conduit 6 still operational.

This is disadvantageous since on operating points of the engine assembly 1 corresponding to operating points of a turbocharger with closed discharge valve, in particular the points at low engine speed and full load, the closing of the relief valve being necessary to maximize the power to the turbine 2, the second exhaust duct 6 of the exhaust system according to the invention is not closed to him, while it would be beneficial to pass all the flow exhaust gas through the turbine 2 by its rotary energy recovery member in the form of a wheel.

Thus, the continuous opening of the second discharge duct 6 decreases the power available to the turbine 2, due to a lower flow rate of gas passing through the impeller of the turbine, which results in a degradation of the response of the engine in transient conditions and steady state. [001 10] It is therefore advantageous to close the second duct 6 said discharge in particular in its branch portion 8 to improve the response of the motor assembly 1 in transient conditions, especially under transient life situation full load and low diet. This can be done by the control valve 13, 13a by closing the outlet end 8b of the branch portion 8 with or without supply of the line RGE 1 1 by the stitching end 12.

[001 1 1] With a second duct 6 said extended discharge in the turbine 2 by one or more bypass portions 8, themselves having one or more outlet ends 8b, the section of the outlet ends 8b can take several forms different to know for example:

a round shape such as, for example, in a conventional turbocharger system,

an optimized form for the optimization of the turbine assembly 2 and its associated casing 2c and the turbulence optimization in the outlet face 2b of the turbine 2, for example a crescent shape, an ovalized or triangular shape, etc. [001 12] Referring to Figures 1a and 2, there is shown two embodiments of a motor supercharging engine controlled by motor distribution. The engine assembly 1 comprises an internal combustion engine and a turbocharger comprising a turbine 2 and a compressor 3. The turbine 2 comprises a wheel recovering at least partially the kinetic energy of the gases passing through it and transmits this energy to the compressor 3.

[001 13] For this, the turbocharger is provided with an axis connecting the wheel of the turbine 2 to a wheel in the compressor 3 ensuring the compression of the air passing through the compressor 3. This axis can be lubricated, cooled by water and / or oil and installed on bearings with or without bearings. This axis may also be equipped with an electrical assistance, either directly on the axis, or with the help of gears, for example a transmission or a gearbox.

[001 14] The exhaust system is connected to an output of the engine for exhaust gas exhaust from the combustion in the engine and comprises a first duct 4 said exhaust turbine 2 from a first exhaust manifold 5 and a second duct 6 said discharge from a second exhaust manifold 7. The first and second manifolds 5, 7 are connected to the outlet of the internal combustion engine for the exhaust gas channeling through the first and second ducts 4, 6. The output of the engine can be constituted by two outlet passages per cylinder on the engine each associated with an exhaust valve but this is not limiting, although this is illustrated in Figures 1a and 2.

The two exhaust manifolds 5, 7 may be close to each other to be connected to the turbine 2, for example by the same exhaust manifold connection flange with a turbine casing 2c 2 The exhaust manifolds 5, 7 may be cooled by a coolant, in particular water, the liquid circulating in a cooling circuit common or not common to the two collectors 5, 7. The cooling circuit or circuits may also serve to cool the inside of the turbine 2.

[001 16] With reference to all the figures, in particular FIGS. 2, 2, 1, 1, 12 and 13, except FIG. 1, according to the present invention according to one embodiment, said at least one stitching portion 8 comprises in part its interior a regulating device 13 of at least its flow rate, the regulating device 13 extending along the inner wall of a portion of said at least one stitching portion 8 leaving between them only a clearance sufficient to a longitudinal displacement of the device in said at least one stitch portion 8, the control device 13 thus occupying substantially the entire section of the portion of the stitching portion 8 along its length.

[001 17] The regulating device 13 is hollow and traversed internally by the exhaust gas by having at least a first outlet opening 14 for the passage of the exhaust gas out of the device. Its displacement in the portion of said at least one stitching portion 8 is effected between a closed position for which said at least one first lateral opening 14 of the device 13 is not aligned with at least one outlet end 8b of said at least one stitching portion 8 and an open position for which said at least one outlet end 8b is aligned with said at least one first lateral opening 14 of the device 13. This is particularly well illustrated in FIGS. 4 to 6.

[001 18] In Figures 10 and 2, the regulating device 13 is symbolically represented by a cross not being shown in detail but could take a different position than those illustrated respectively in these figures. For example, in FIG. 1a, the regulation device 13 can be positioned closer to the intersection between the second duct 6 and the first duct 4, the quilting end 12 being able to be brought closer to this intersection as well. . In Fig. 2, the regulator 13 may be positioned closer to the outlet end 8b of the branch portion 8 as illustrated. [001 19] With reference to FIGS. 2, 3, 1 1, 12 and 13 in particular, in this embodiment of the invention, the stitching of the line RGE 1 1 is done on at least one stitching portion 8 of one of the first and second conduits 4, 6 internal to the turbine 2 via at least one stitching end 12, said portion 8 comprising the regulating device 13 for the regulation of at least one exhaust gas flow therethrough, the device for 13 is not shown in detail in this figure but is shown in Figures 4 to 6. Still in this embodiment, the control device 13 is simply shown symbolically and placed at the output end 8b of the Bypass portion 8. In fact the regulating device 13 can be inserted into the branch portion 8 and the outlet end 8b is then positioned laterally to the branch portion. [00120] Preferably, the portion or portions on which the stitching is made via at least one stitching end 12 is one or more bypass portions 8 of the second duct 6 bypassing the wheel of the turbine 2, this to obtain a line RGE 1 1 high pressure. This is however not limiting and if in FIG. 2 the stitching portion 8 is merged with the extension portion extending in the turbine 2 the second duct 6, the stitching portion may be placed on the main relief passage 4 'extending in the turbine the first duct 4.

In one embodiment of the present invention, as can be seen in Figures 1 1, 12 and 13, the movement of the control device 13 is controlled by an actuator 15 external to the control device 13 and stopping the displacement in intermediate opening positions for adjusting the output flow of said at least one nozzle portion 8, preferably but not necessarily at least one branch portion 8 extending the second conduit 6 according to the degree of opening corresponding to each position respective intermediary. Alternatively, the actuator 15 can stop the displacement of the regulating device 13 in intermediate opening positions for adjusting the output flow rate of said at least one stitching portion 8 according to the degree of opening corresponding to each intermediate position. respectively.

In a very advantageous embodiment of the regulating device 13 which can be seen in FIGS. 1 1, 12 and 13, the regulating device 13 comprises at least a second lateral opening 18 for exhaust gas exit. stitching of the line EGR 1 1 being effective on said at least one stitching portion 8 when said at least one stitching end 12 is aligned with said at least one second lateral opening 18 of the device 13. embodiment, the first (s) and second (s) lateral openings 14, 18 are positioned on the regulating device 13 so that they are selectively positioned with respectively said at least one outlet end 8b of the stitching portion 8 or said at least one stitching end 12. This sub-embodiment is shown in FIGS. 4 to 6. In FIG. 11, the flow of exhaust gas passes through the outlet end 8b of the p stitching orifice 8 without feeding the line RGE by the stitching end 12. In FIG. 5, the flow of exhaust gas is interrupted both for the outlet end 8b of the stitching portion 8 and the line EGR by the stitching end 12. In FIG. 6, the flow of exhaust gas passes through the stitching end 12 to feed the EGR line without passing through the outlet end 8b of the stitching portion 8 to continue its crossing of the exhaust system.

According to another embodiment not shown in Figures 1 1, 12 and 13 but with reference to these figures for numerical references, the first (s) and second (s) lateral openings 14, 18 may be positioned on the regulating device 13 so that when one of said at least one opening 14, 18 is aligned with at least one outlet end 8b of the stitching portion 8 or at least one end 12, the other of said at least one opening 18, 14 is partially aligned with said at least one stitching or outlet end 12, 8b respectively leaving a reduced passage to the exhaust leaving the control device 13 by the stitching or outlet end 12, 8b respective.

In this case, with reference to FIGS. 2, 3, 1, 12 and 13, there is a sharing of the flow of exhaust gas between the outlet of the stitching portion 8 opening into the rest of the system. the exhaust and the line RGE 1 1, this partition being adjustable according to the displacement of the regulating device 13 allowing a more or less pronounced alignment of the lateral openings 14, 18 of the gas outlet with their stitching end 12 or their outlet end 8b of the stitching portion 8.

Advantageously, the part of the stitching portion or portions 8 receiving the regulating device 13 as well as the regulating device 13 are of cylindrical shape, said at least first and second lateral openings 14, 18 being disposed on the wall of the cylinder formed by the regulating device 13.

In order to initiate the movement of the regulating device 13 in the part of the stitching portion receiving it, an actuator 15 is provided. In a preferred embodiment, the regulating device 13 comprises a closing head 21 while capping an circular end portions of the cylinder formed by the control device 13, an actuator 15, outside the control device 13, pressing the head 21 for the displacement of the device 13 in translation.

In one embodiment, the actuator 15 may have a rod 15a passing through the stitching portion 8, one end of the rod 15a pressing on the head 21 while the other end is on the outside of the 8. When the control device 13 is in the turbine 2 provided with its housing 2c, as shown in Figure 3, the other end is outside the housing 2c of the turbine 2.

[00130] Still in this embodiment shown in Figures 1 1, 12 and 13, a return spring 22 which can be wound around the rod 15a inside the stitching portion 8. This spring 22 is disposed of so as to recall the regulating device 13 in the position for which said at least one first lateral opening 14 is aligned with said at least one outlet end 8b of said at least one stitching portion 8. The main function of the spring is here a safety in case of failure of the control system, the system returns to the initial position: all flow goes to the exhaust, the engine will not be able to operate at its maximum power in case of control problem, but it is a mechanical degraded mode tolerated in case of failure of the control system. This can be done both in the casing 2c of the turbine 2, as shown in FIG. 3, and at another location of the exhaust system on any of the first and second ducts 4, 6.

Claims

An engine assembly (1) comprising an internal combustion engine comprising at least one cylinder, at least one exhaust gas recirculation line at an engine intake, a turbocharger having a turbine (2) and a compressor (3), and an exhaust system connected by a first and a second exhaust manifold (5, 7) to an engine outlet for exhaust gas exhaust from combustion in the engine, the exhaust system comprising a first conduit (4) said exhaust by the turbine (2) starting from the first exhaust manifold (5) and a second duct (6) said discharge from the second exhaust manifold (7), the turbine (2) being provided with a casing (2c) having a main expansion passage (4 ') in which is housed a turbine wheel and the first duct (4) opening into the main relief passage (4') by a face of inlet (2a) of the housing (2c), characterized in that the second leads me (6) opens through the inlet face (2a) of the housing (2c) in at least one branch portion (8) internal to the housing (2c) bypassing the main relief passage (4 ') and in that the tapping of the at least one recirculation line (1 1) is carried out in the turbine (2) on a stitching portion (8) of at least the main expansion passage (4 ') or of said at least one portion bypass (8) via at least one stitching end (12).

An assembly according to claim 1, wherein the stitching portion (8) on which stitching is performed via at least one stitching end (12) is said at least one branch portion (8) extending the second conduit (6) and bypassing the wheel of the turbine (2), the exhaust system comprising a third duct (9) outside the turbine (2) and connected to an outlet face (2b) of the turbine casing (2c) for evacuation exhaust gases out of the turbine (2).

An assembly according to claim 1 or 2, wherein the stitching portion (8) comprises at least one regulating valve (13, 13a) for regulating the flow of exhaust gas therethrough, said at least one regulating valve ( 13, 13a) being operable between at least a first flow closure position in the stitching portion (8) at or after said at least one stitching end (12) and a second flow opening position in the staple portion (12). stitching (8) at or after said at least one stitching end (12). An assembly according to claim 3, wherein the regulating valve (13, 13a) is disposed towards at least one outlet end (8b) of said at least one stitching portion (8) at an outlet face (2b) of the turbine (2), intermediate positions of opening of the control valve (13, 13a) for adjusting the flow rate in said at least one nozzle portion (8) according to the degree of opening of the control valve (13); , 13a) corresponding to each respective intermediate position.

An assembly according to claim 3, wherein the control valve (13, 13a) is operable between at least four positions, namely:

a first closing position of said at least one stitching portion (8) and said at least one stitching end (12) with a zero flow in said at least one stitching portion (8) and in said at least one stitching portion (8); recirculation line (1 1),

a second closing position of said at least one stitching portion (8) with a zero flow rate in said at least one stitching portion (8), the exhaust gases flowing entirely into said at least one recirculation line; (1 1) via said at least one stitching end (12),

a third position for closing said at least one recirculation line (1 1) by closing said at least one stitching end (12) with a zero flow rate in said at least one recirculation line (1 1), exhaust gas in this stitching portion (8) flowing entirely to at least one outlet end (8b) of said at least one stitching portion (8),

fourth fourth positions of opening of said at least one stitching portion and said at least one recirculating stitching end, said intermediate opening positions making it possible to adjust the flow towards said at least one outlet end (8b) in said at least one stitching portion (8) and in said at least one recirculation line (1 1) according to the degree of opening of said at least one stitching portion (8) and said at least one stitching end (12) corresponding to each respective intermediate position.

An assembly according to claim 4 or 5, wherein, when the stitching portion is said at least one branch portion (8), the regulating valve (13, 13a) comprises a disc (29) displaceable in translation or rotation by an actuator (15), the disk (29) carrying said at least one output end (8b) of said at least one branch portion (8) and said at least one stitching end (12) of said at least one line recirculation (1 1). An assembly according to any of claims 4 to 6, wherein said at least one outlet end (8b) of said at least one stitching portion (8) is of circular, oval or half-moon shaped section.

An assembly according to any one of the preceding claims, wherein the housing (2c) of the turbine remotely surrounds the wheel of the turbine (2) and comprises an intermediate portion interconnecting its inlet face with an exit face ( 2a, 2b) of the housing (2c), the intermediate portion comprising at least one opening (12a) for said at least one stitching (12) of said at least one recirculation line (1 1).

Engine assembly (1) according to claim 1, comprising an internal combustion engine comprising at least one cylinder, a turbocharger comprising a turbine (2) and a compressor (3), an exhaust system connected to an output of the engine for a evacuation of exhaust gases from the combustion in the engine and at least one recirculation line (1 1) of the exhaust gas at an engine intake, the exhaust system comprising a first conduit (4) said exhaust by the turbine (2) starting from a first exhaust manifold (5) and a second discharge duct (6) extending from a second exhaust manifold (7), the turbine (2) being provided with a casing (2c) having a main expansion passage (4 ') in which is housed a turbine wheel and the first duct (4) opening into the main relief passage (4') through an inlet face (2a ) of the housing (2c), the recirculation line (1 1) having at least one stitching end

(12) on at least a portion of stitching (8) traversed by exhaust gas, characterized in that said at least one stitching portion (8) comprises in its interior a regulating device (13) of at least its flow, the regulating device

(13) extending along the inner wall of a portion of said at least one stitching portion (8) leaving therebetween only a clearance sufficient for longitudinal movement of the device in said at least one stitching portion ( 8), the regulating device (13) being hollow and internally traversed by exhaust gases by having at least a first outlet exhaust opening (14), the displacement being effected between a closed position for which said at least one first lateral opening (14) of the device (13) is not aligned with at least one outlet end (8b) of said at least one stitching portion (8) and an open position for wherein said at least one first lateral opening (14) of the device (13) is aligned with said at least one outlet end (8b).

10. An assembly according to the preceding claim, wherein the second duct (6) opens through the inlet face (2a) of the housing (2c) in at least one branch portion (8) internal to the casing (2c) bypassing the passage main detent (4 '), the main relief passage (4') and said at least one branch portion (8) joining an outlet face (2b) of the casing (2c), the exhaust system comprising a third duct (9) external to the turbine (2) connected to the outlet face (2b) of the turbine casing (2c) for exhaust gas discharge from the turbine (2).

11. An assembly according to the preceding claim, wherein the displacement of the regulating device (13) is controlled by an actuator (15) external to the regulating device (13) and stopping the displacement of the regulating device (13) in intermediate positions. opening to adjust the output flow of said at least one stitching portion (8) according to the degree of opening corresponding to each respective intermediate position. 12. The assembly of claim 10 or 1 1, wherein the regulating device (13) comprises at least a second lateral opening (18) for exhaust gas outlet, the stitching of the recirculation line (1 1) being effective on said at least one stitching portion (8) when said at least one stitching end (12) is aligned with said at least one second lateral opening (18) of the device (13). 13. Assembly according to any one of claims 10 to 12, wherein the portion of said at least one stitching portion (8) receiving the regulating device (13) and the regulating device (13) are of cylindrical shape, said at least one first lateral opening (14) and said at least one second lateral opening (18), when present, being disposed on the wall of the cylinder formed by the regulating device (13).

14. Assembly according to the preceding claim, wherein the regulating device (13) comprises a head (21) closing by capping one of the circular end portions of the cylinder formed by the regulating device (13), an actuator (15). pressing the head (21) for moving the device (13).

15. An assembly according to the preceding claim, wherein the regulating device (13) is positioned inside the turbine (2), the housing (2c) remotely surrounding the turbine (2) comprising an intermediate portion connecting between them the inlet faces (2a) with the outlet face (2b) of the housing (2c) and the actuator (15) has a rod (15a) passing through the housing (2c), one end of the rod (15a). ) pressing the head (21) while the other end is outside the turbine (2).