FR2864999A1 - Heat engine e.g. direct engine diesel engine, has waste gas exhaust control unit partially closing connection of combustion chamber to exhaust manifold to permit passage of high pressure waste gas from chamber to another chamber - Google Patents

Abstract

The engine (1) has a waste gas supply unit (9) that connects combustion chambers (2a, 2b). A waste gas exhaust control unit (7a) selectively opens connection between the chambers and partially closes connection of the chamber (2a) to an exhaust manifold (8), when in a waste gas supply configuration. The partial closing permits selective passage of high pressure waste gas from the chamber (2a) to the chamber (2b). An independent claim is also included for a waste gas injection method for a heat engine.

Description

THERMAL ENGINE AND METHOD FOR INJECTING BURNED GASES

  The present invention relates generally to the field of injection of burnt gases into a heat engine chamber.

  More particularly, according to a first aspect shown in Figure 1, the invention relates to a heat engine 1, such as a direct injection diesel engine, comprising at least a first and a second combustion chamber 2a, 2b, first and second fuel injection means 3a, 3b for respectively injecting fuel into the first and second chambers 2a, 2b, first and second intake means 4a, 4b to admit respectively and selectively, in the first and second chambers 2a, 2b, a gaseous oxidizer containing air, first exhaust gas control means 7a selectively connecting the first chamber 2a to an exhaust manifold 8 to selectively allow the escape of flue gas from the first chamber 2a, a means for supplying burned gases 9 to at least supply the second chamber 2b with burnt gases.

  According to a second aspect, the invention relates to an injection method for a heat engine, such as a direct injection diesel engine, comprising in particular a first and a second combustion chamber, first and second fuel injection means for fuel injection. respectively injecting fuel into the first and second chambers, first and second intake means for respectively and selectively permitting, in the first and second chambers, a gaseous oxidant containing air, first exhaust control means of the flue gas selectively connecting the first chamber to an exhaust manifold for selectively allowing the escape of flue gases from the first chamber, a flue gas supply means selectively connecting the first and second chambers together.

  The use of so-called recirculating gas or EGR or recycled gas or flue gas in the combustion chambers of an alternating engine and more particularly of a compression-ignition engine such as a diesel engine with direct injection is well known in the art. skilled person. The recycled gases are gases resulting from the combustion of oxidant and fuel in a combustion chamber. These gases are generally formed during previous cycles and are therefore depleted of oxygen. They are used, mixed with air, to reduce polluting emissions such as emissions of nitrogen oxides or to control the course of combustion. More precisely, the ignition time of an air / fuel mixture containing recycled gases is greater than that of an equivalent mixture that does not contain them. It is therefore possible to delay the ignition of an air / fuel mixture by adding recycled gases to a maximum concentration limit beyond which fuel combustion will be difficult and incomplete, at the risk of producing particles. polluting.

  External EGR is when the supply of recycled gas is via a circuit located outside the combustion chamber and internal EGR when these residual combustion gases have remained trapped in the combustion chamber. The proposed invention relates mainly to the management of external EGR and the preparation of a preferentially homogeneous mixture of air and recycled flue gas. A homogeneous combustion engine is an engine in which the fuel / oxidant ratio is substantially constant throughout the combustion chamber. The use of this homogeneous mixture allows a reduction of noise and pollution generated by the engine.

  The homogeneous combustion engine operates by self-ignition of a homogeneous charge obtained for example, by injecting the fuel very early in the compression phase. It undergoes favorable conditions for the reaction mechanisms and thus for self-ignition over a longer period than in the case of the conventional combustion diesel engine. In order to extend the operating range of the homogeneous combustion engine to medium loads, this is to avoid premature self-ignition of the load. Ideally, the ignition should be near the top dead center (position in which a piston is closest to the cylinder head). The general parameters controlling the autoignition time are as follows.

  the evolution of the pressure and the temperature in the cylinder and in particular their maximum values which depend on the compression ratio; the rate of internal burnt gas (residual burnt gases in the chamber) and external burned gases contained in the chamber at the end of the admission, they intervene via their temperature and their dilution effect of the air / fuel mixture; the richness of the fuel / air mixture.

  The rate of externally recycled flue gas is proving to be one of the most important parameters for controlling combustion.

  However, the rate of burnt gases recycled in a cylinder can be relatively high and greater than 60% of the volume of gas injected. In order to be able to extend the range of the use of homogeneous combustion throughout the entire cycle range, it is necessary to introduce a high rate of recycled flue gases at relatively high loads and motor speeds. This will require very high burnt gas boost pressures to achieve a substantially stoichiometric mixture of oxidant / fuel. For example, for a given operating point at 2500 rpm and 10 bars of PMI (average pressure indicated inside a chamber), it would require a rate of flue gas in the chamber greater than 60% (ratio of the mass of gases burned in the chamber relative to the total mass of air in the chamber) and therefore a boost pressure of more than 2.5 bars. Such supercharging pressure and such recycled flue gas rates can not be achieved with existing turbocharging technologies and conventional combustion chamber feeds and circuits.

  On the other hand, new standards regulating the emissions of flue gases, in particular the EURO V and ULEV / SULEV standards for the United States, should impose a reduction of NOx (Nitrogen Oxide) emissions at the exhaust of at least 85% compared to current engines.

  As mentioned earlier, the pollution level of an engine can be reduced by increasing the rate of flue gases in the combustion chambers.

  In summary, such an increase in the rate of flue gases can make it possible: to homogenize the combustion, to reduce the areas which are proportionally too rich in fuel with respect to the quantity of air and flue gases of this zone; dilute the mixture in the combustion chamber.

  This is the reason why many engine manufacturers have developed various solutions to introduce flue gases into engine combustion chambers.

  An engine of the previously defined type, allowing such an injection of flue gases into chambers, is for example described in FIG. 1.

  During an engine cycle, the combustion chambers of this engine each generate in turn exhaust gases which are directed to the exhaust manifold 8. A portion of these burned gases can be recycled on demand to one or the other of the chambers 2a or 2b by means of a flue gas supply means 9 comprising a pipe 14 connected to the duct 13 of the exhaust manifold 8. First and second intake valves burners 5a and 5b respectively control the admission of gas into the first chamber 2a and the second chamber 2b.

  The flue gases can be admitted to a chamber only when the pressure inside this chamber is lower than the pressure of the flue gases inside the exhaust manifold 8, which limits the possibilities of gas injection. burned in terms of injection moment and maximum volume of injectable flue gas.

  In this context, and in order to provide a less polluting engine, the present invention aims to provide an engine and a method for increasing the amount of flue gas injected into a combustion chamber.

  For this purpose, the heat engine according to the first aspect of the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the means for supplying burnt gas selectively connects between they the first and second chambers, the first exhaust gas control means being adapted to selectively adopt a first configuration of supply of burned gases preferably at high pressure in which these first exhaust gas control means 7a : open the selective connection between the first and second chambers and; at least partially coordinate the connection of the first chamber to the exhaust manifold, thereby allowing selective passage of the flue gases preferably at high pressure from the first to the second chamber.

  For the same purpose, the injection method for a heat engine according to the second aspect of the invention, which moreover conforms to the generic definition given in the preamble above, is essentially characterized in that it comprises: A first step in which the conditions of a combustion are created in the first chamber by injecting fuel and an oxidant, this combustion producing flue gas; a second step after the first in which is injected into the second chamber at least a portion of the flue gas produced during the first step, at least partially closing the selective passage of the flue gases from the first chamber to the exhaust manifold and by then communicating the first chamber and the second through said means for supplying burnt gases, thus making it possible to supply the second chamber with preferably high-pressure burnt gases.

  The fact of interconnecting the first and second chambers and at least partially closing the connection between the first chamber and the exhaust manifold makes it possible to collect at least a portion of the flue gases from the first chamber which have a high pressure and transfer them to the second chamber which has a much lower internal pressure, the term high pressure designating gases having a higher pressure than the gases present in the exhaust manifold which are themselves at low or medium pressure.

  This is possible because the combustion generating high pressure flue gases in the first chamber is offset in time with respect to combustion occurring in the second chamber. To achieve the invention, it is preferable to connect together combustion chambers whose pressure differences at the same time of the cycle are the most important. Thus, preferably there will be connected rooms whose respective top dead centers are offset relative to each other in the engine cycle. This offset being preferably the largest possible, that is to say at best a half engine cycle.

  The pressure difference between the first and second chambers which naturally exists in a conventional combustion engine is thus put to advantage by means of the engine and the method according to the invention for increasing the quantity of flue gases that are admissible in a combustion chamber by injecting therein not low or medium pressure gas but mainly high pressure flue gases.

  The window of time in which the flue gases can be injected during a motor cycle, in a chamber is thus increased compared to what it is in the engines of the prior art that do not allow the injection of high flue gases. pressure.

  According to a further exemplary embodiment of the invention, it is provided that in the first configuration, the first exhaust gas control means completely open the connection between the first and second chambers and completely close the connection of the first chamber. at the exhaust manifold.

  In this case, the chambers are in direct communication and the pressure of the burnt gases injected into the second chamber is greater than it is in the case where the connections between the first and second chambers and between the first chamber and the collector. exhaust are partially open.

  Other characteristics and advantages of the invention will emerge clearly from the description which is given hereafter, by way of indication and in no way limiting, with reference to the appended drawings, in which: FIG. 1 represents a motor of the art prior; FIG. 2 represents a first embodiment of the invention provided with a single burnt gas supply circuit; Figure 3 shows a second embodiment of the invention provided with two burned gas supply circuits; FIG. 4 represents a third embodiment of the invention provided with two burned gas supply circuits; Figures 5 and 6 show a fourth and a fifth embodiment of the invention applied to a four-cylinder engine with two turbos coupled in parallel.

  Figure 1 shows a conventional engine of the prior art having a first combustion chamber 2a and a second combustion chamber 2b. The chambers 2a and 2b are adapted to allow the sliding of a piston per chamber.

  The first and second chambers 2a and 2b are respectively supplied with fuel by the first and second fuel injection means 3a and 3b which are conventional injection means such as diesel engine injectors.

  First and second intake means 4a and 4b allow the admission into the chambers of an oxidizer such as air and flue gases.

  The air and the flue gases pass through a common passage such as a feed ramp where they are mixed and conveyed to the chambers 2a and 2b. Each of the intake means 4a and 4b comprises a closure means such as a valve (not shown in the figures) for selectively closing or selectively opening the supply inlet of the chamber 2a, 2b with which it communicates.

  The first intake means 4a feeds the first chamber 2a and the second intake means 4b feeds the second chamber 2b.

  The flue gases from the combustion chambers 30 escape through a first flue gas collection duct 6a connected to the first chamber 2a and a second flue gas collection duct 6b connected to the second chamber 2b. These first and second ducts 6a and 6b respectively collect the flue gases from the chambers 2a and 2b and convey them to an exhaust manifold 8 to which they are connected via a collector duct 13.

  A flue gas supply means 9 comprises a main flue gas supply duct 14 connected to the collector duct 13. The main supply duct 14 conveys a portion of the flue gases from the collector duct 13 to the flue gas supply means 14. intake 4a and 4b to which it is selectively connected by valves 5a and 5b.

  Thus, when the valve 5a is open, the flue gases are injected into the first chamber 2a via the first intake means 4a, in the same way when the valve 5b is open, the flue gases are injected into the second chamber 2b. passing through the second intake means 4b.

  As mentioned above, this engine allows the injection of low or medium pressure flue gas, that is gas whose pressure is substantially equal to the pressure prevailing in the exhaust manifold 8 which has an opening to the exhaust. 'outdoors.

  FIGS. 2 to 4 show embodiments of the motor according to the invention based on the engine of the prior art which has just been presented with reference to FIG.

  Thus, except in particular cases specifically mentioned, the preceding detailed description of the engine of the prior art of FIG. 1 therefore applies to the motors of FIGS. 2 to 4.

  The engine 1 of FIG. 2 is provided with a vent valve 7a 'disposed on the manifold duct 13, between the exhaust manifold 8 which allows exhaust gases to be vented to the open air. and the main flue gas supply duct 14 which connects the collector duct 13 to the chambers 2a and 2b to conduct the flue gases.

  The venting valve 7a 'is a flue gas escape control means which makes it possible or not to allow exhaust gases to escape from the chambers 2a, 2b to the exhaust manifold 8.

  In this first embodiment, the flue gas supply means 9 comprises a main flue gas supply duct 14 which is subdivided into first and second flue gas supply ducts 14a and 14b opening directly and respectively into each other. the first and second chambers 2a and 2b, without passing through the first and second intake means 4a and 4b.

  The first and second burned gas inlet valves 5a and 5b are respectively disposed on the first and second flue gas supply conduits 14a and 14b for selectively opening or closing the direct flow of the high pressure flue gases to the chambers 2a. and 2b.

  When this vent valve 7a 'is closed and one of the first or second flue exhaust control means 7a or 7b is open, the pressure within the main supply line 14 is higher and higher than it would be if the vent valve 7a 'were completely open.

  Thus, when the valve 7a 'is closed, the flue gases supplied by the flue gas supply means 9 are in this embodiment of the high pressure gas.

  Advantageously, the first exhaust control means 7a, 7b and / or optionally the venting valve 7a 'and / or possibly the flue gas admission valves 5a, 5b are suitable means for controlling variations continuous flows of said burnt gases passing through the connection between the first and second chambers 2a, 2b and / or passing through the connection between the first chamber 2a to the exhaust manifold 8. All or part of these exhaust control means 7a 7b and the valves used in the present invention may be proportional opening valves or all or nothing valves.

  This controlled flow rate variation makes it possible to refine the combustion gas injection pressures in the chambers of the engine 1, as well as the flows of gas passing either towards the exhaust manifold 8 or between the chambers 2a, 2b.

  The second exhaust gas control means 7b selectively connecting the second chamber to the exhaust manifold 8, allows the engine 1 to selectively adopt a second high pressure flue gas supply configuration in which the second control means exhaust gases 7b open the connection between the first and second chambers 2a, 2b and close the connection of the second chamber 2b to the exhaust manifold 8, thus allowing the selective passage of high pressure flue gas from the second chamber 2b to the first chamber 2a.

  With this embodiment the first and second chambers 2a and 2b are in turn used as a source of high pressure flue gases, these gases passing either from the first chamber to the second or from the second to the first.

  The first exhaust gas control means 7a comprise: either an exhaust valve 7a selectively connecting the first chamber 2a to the exhaust manifold 8 and a first valve (5b in the case of Figure 2 and 5b ' in the case of Figure 3) selectively connecting the first chamber to the second; or a first three-way valve (denoted 7a in FIGS. 4 to 6) provided with a burned gas inlet connected to the first chamber 2a, with a first exhaust outlet (constituted by the first flue gas collection duct) 6a of Figures 4 to 6), selectively connected to the exhaust manifold and a first burned gas outlet (denoted 11 in Figures 4 to 6) selectively connecting the first chamber 2a to the second 2b, this three-way valve being adapted so that in burned gas supply configuration, the burned gas inlet is only connected to the first burned gas outlet, as is the case in the example of Figure 4.

  A system similar to that just described can be provided for the second flue gas exhaust control means 7b which then comprise: either an exhaust valve 7b selectively connecting the second chamber 2b to the exhaust manifold 8 and a first valve (5a in the case of Figure 2 and 5b 'in the case of Figure 3) selectively connecting the first chamber to the second; a second three-way valve (not shown in the figures for the sake of clarity, but similar to the three-way valve of FIG. 4) provided with a burned gas inlet connected to the second chamber 2b, a first outlet exhaust, selectively connected to the exhaust manifold 8 and a first burnt gas outlet selectively connecting the first chamber 2a to the second 2b, this three-way valve being adapted so that in the configuration of high burnt gas supply pressure of the first chamber, the burned gas inlet is only connected to the first outlet of burnt gas, to selectively direct all the flue gases from the second chamber 2b to the first chamber 2a.

  It can also be provided that the flue gas supply means 9 selectively interconnecting the first and second chambers comprise a first connecting duct 11 for conducting the flue gases from the first to the second chamber and a non-return means such as a check valve connected to the first conduit 11 and adapted to allow only the passage of flue gas from the first to the second chamber.

  A similar system may be provided to allow only flue gas passage from the second to the first chamber.

  Such non-return means allow the automatic passage of gas from one chamber to the other, when the pressure difference between the two chambers exceeds a threshold value of opening of the antiretour means. This threshold value is intended to correspond to a high pressure of burnt gases released by combustion in one of the chambers.

  The connection duct or ducts 11, 11 'between the chambers are designed to withstand the transfer of high-pressure burnt gases, and may for example be integrated as ducts external to the cylinder head, or preferably as ducts integrated directly into the cylinder head or in the engine block.

  Advantageously, the high pressure flue gas transfer link can be used exclusively for injecting large quantities of flue gases (via the connecting duct 11) and a complementary low-pressure connection (via the main flue gas supply duct 14). Figures 3 to 6) can be used to inject low or medium pressure flue gases.

  Thus, preferably low-pressure flue gas recirculation means 12 selectively connecting the exhaust manifold 8 to at least one of the chambers 2a, 2b and including first flow control means such as the valves 5a and 5b of the figures 2 to 4 may be used to recycle a portion of the flue gas exhaust manifold 8 to at least one of the chambers.

  This low pressure flue gas injection system is therefore complementary to the high pressure flue gas injection system, the first being preferentially used during the oxidant inlet phase which is a phase performed at relatively low pressure with the combustion medium. admission 4a or 4b open and the second being preferably used after this admission phase to allow the injection of flue gas into a chamber after the corresponding inlet means has been closed, and during the rise of the piston_ of its point dead down to his top dead center.

  This second injection of high-pressure flue gases makes it possible to reach high concentrations of burnt gases injected into a chamber going beyond 70% (mass of flue gases relative to the total mass of gaseous fluid contained in the chamber), which allows to create the conditions of a homogeneous combustion.

  It is preferable to ensure that the flue gas supply means 9 comprises a high pressure transfer circuit dedicated solely to the transfer of gas between these two chambers, as is the case in the example of FIG. this transfer circuit is composed of a connecting pipe 11, the two ends of which open directly into the first and second chambers 2a, 2b respectively. The passage between the chambers is simply controlled by the first burned gas inlet valve 5b 'which is positioned on the connecting pipe 11, between the chambers 2a and 2b.

  With this second embodiment of Figure 3, it is possible to transfer high pressure flue gas between two chambers regardless of whether the exhaust valves of the chamber in which these gases are collected is open or closed.

  This embodiment makes it possible to vary at any time the pressure and temperature conditions and the mass of burnt gas remaining inside the combustion chambers by connecting them to one another.

  FIG. 4 represents a motor according to the invention identical to that of FIG. 3 except that the valves 5b 'and 7a of the motor of FIG. 3 are replaced by a first three-way valve 7a. As previously mentioned, this valve 7a has a burnt gas inlet, a first exhaust outlet selectively connected to the exhaust manifold 8 and a first burned gas outlet connected to the second chamber 2b.

  This valve 7a selectively adopts: a position allowing only the connection between the first chamber 2a and the exhaust manifold 8; a position permitting only the selective connection between the chambers 2a and 2b when the engine is in the high pressure flue gas supply configuration of one of the chambers; a blocking position in which the connection between the chambers is prohibited, and the connection between the first chamber 2a and the exhaust manifold 8 is also prohibited.

  This single three-way valve 7a thus makes it possible to manage: the exhaust gas exhaust function of the first chamber 2a, and the burn gas transfer function from the first chamber 2a to the second chamber 2b.

  FIGS. 5 and 6 show four-cylinder engines whose order of ignition of the cylinders is 1, 3, 4, 2 (the rolls are numbered from 1 to 4 starting from the line to the left of FIG. ).

  The first chamber 2a which corresponds to the cylinder 1 and the second chamber 2b which corresponds to the cylinder 4 are connected to each other and to the collector duct 13, as described for FIG. 4. A three-way valve 7a identical to that described hereinabove. above is connected to the first and second chambers 2a, 2b and to the collector duct 13 in the manner described in FIG. 4.

  Third and fourth combustion chambers 2c and 2d respectively corresponding to the cylinders 2 and 3 are connected to each other and to the collector duct 13, as described for FIG. 4. A three-way valve 7a 'of structure identical to that 7a described above is connected to the third and fourth chamber 2c and 2d and to the collector duct 13 in the manner described in FIG. 4.

  According to a complementary embodiment, these three-way valves 7a and 7a 'can be respectively equipped with non-return valves.

  The cylinders are connected together by the first connecting ducts 11 for the rolls 1 and 4 and by the first connecting duct 11 'for the rolls 2 and 3. The rolls connected together by the connecting ducts 11 and 11' are those whose ignition moments are shifted and spaced as far as possible during the engine cycle.

  The collector duct 13 makes it possible to route the exhaust gases either to an exhaust manifold for venting them to the open air, or directly to a common intake manifold 15 connected to all the chambers 2a, 2b. , 2c, 2d.

  This common intake ramp 15 which is part of the recirculation means 12, is also connected to a cooled pulsed air intake. Thus, this ramp 15 makes it possible to mix low or medium pressure flue gases with air and to convey this mixture to the inlet means of each of the chambers.

  Motor 1 of FIG. 5 is a motor having a twin-turbo system connected in parallel.

  The engine 1 of FIG. 6 is a motor comprising a bi-turbo system connected in series.

  In a particular mode of operation of the engine of FIGS. 5 and 6, certain chambers such as the second and fourth chambers 2b and 2d are high-pressure gas-fired receiving chambers and operate with very high rates of flue gases which can reach 70 which allows to realize in these rooms homogeneous combustions. Other combustion chambers such as the first and second combustion chambers 2a and 2c are burned gas emitters to the receiving chambers 2b, 2d and are not connected directly to the motor output. In this case, only the receiving chambers 2b, 2d are connected to the exhaust manifold 13, the so-called emitting chambers 2a and 2c of burnt gases being only connected selectively to the receiving chambers 2b and 2d. The flue gas emitting chambers then operate preferentially with very low levels of EGR, in conventional combustion.

  Optionally, several emitter chambers may be diverted to the same receiving chamber.

  The flow of exhaust gas supplied by such an engine may therefore be variable depending on whether the engine is in normal operation, ie when there is no injection of high-pressure flue gases from a chamber. to a receiving chamber, or depending on whether the engine is operating by transferring high pressure flue gases from one chamber to another.

  When this engine is equipped with turbo compressor called T / C (Figures 5 and 6), the flow of exhaust gas supplied to the turbine is variable, which requires a small T / C to treat low rates of flue gas and a large T / C suitable for large flows, when the engine is in normal operation.

  For example, for a 4-cylinder engine and a sequence of successive ignition cylinders 1, 3, 4, 2, it is necessary to completely divert the exhaust from the cylinder 3 to the cylinder 2 and also completely derive the exhaust gas from the cylinder 4 to the cylinder 1 to fill the cylinders 1 and 2 with high rate of high pressure burnt gas. Thus, the rate of burnt gases in the receiving cylinders can be more than 70% at 1500 and 2500 rpm and up to 13 bars of PMI, with a richness of 0.9 (that is to say with 90% by weight air for 10% by mass of fuel). Cylinders 3 and 4 which are not connected to the engine outlet have almost no burnt gas content.

  When lower levels of recycled flue gas concentrations are desired, all cylinders need only use a conventional flue gas recirculation circuit, for example by transferring part of the exhaust gas from the collector duct. to the intake ramp 15.

  The engine and the method according to the invention can be controlled according to two alternatives: either by a so-called open-loop control, where the configuration of the winnowing system (choice and positioning of the different valves) is mapped and adapted according to the conditions engine operating conditions (engine speed, load, pressure and water temperature conditions, etc.) measured on the engine; either by a so-called closed-loop control, where the configuration of the winnowing system is directly looped on an information measured on the engine: for example, a pressure sensor on one of the cylinders, or an accelerometer placed on the structure of the engine, or still an ionization probe, each allow to detect the start time of the combustion. In this configuration, the engine control computer continuously adjusts the position of the variable valve systems to control the desired combustion start time in the different chambers (previously mapped as a function of the engine operating conditions).

  Finally, the motors described in FIGS. 2 to 6 use the method according to the second aspect of the invention.

Claims (9)

  A heat engine (1), such as a direct injection diesel engine, comprising at least first and second combustion chambers (2a, 2b), first and second fuel injection means (3a, 3b). for respectively injecting fuel into the first and second chambers (2a, 2b), first and second intake means (4a, 4b) for respectively and selectively permitting, in the first and second chambers (2a, 2b), an oxidant gas containing air, first exhaust gas control means (7a) selectively connecting the first chamber (2a) to an exhaust manifold (8) for selectively allowing exhaust of burnt gases out of the first chamber (2a), a means for supplying burnt gases (9) to at least supply the second chamber (2b) with burnt gases, the engine being characterized in that the flue gas supply means (9) connects selectively between them the first and second cha mbres (2a, 2b), the first exhaust gas control means being adapted to adopt selectively a first burned gas supply configuration in which these first exhaust gas control means (7a) open the selective connection between the first and second chambers (2a, 2b) and at least partially coordinate the connection of the first chamber (2a) to the exhaust manifold (8), thereby permitting the selective passage of the flue gases preferentially to high pressure from the first (2a) to the second chamber (2b).   2. Engine (1) according to claim 1 characterized in that in the first configuration the first flue gas exhaust control means (7a) fully open the connection between the first and second chambers (2a, 2b) and close totally connecting the first chamber (2a) to the exhaust manifold (8).   3. Engine (1) according to any one of claims 1 or 2 characterized in that the first exhaust control means are suitable means for controlling continuous variations in flow rates of said burned gases passing through the connection between the first and second chambers (2a, 2b) and / or passing through the connection between the first chamber (2a) and the exhaust manifold (8).   4. Engine (1) according to any one of claims 1 to 3 characterized in that it comprises a second exhaust gas control means (7b) selectively connecting the second chamber to the exhaust manifold to selectively open exhausting flue gases from the second chamber (2a), the engine then selectively adopting a second burned gas supply configuration in which the second flue exhaust control means (7b) opens the connection between the first and second chambers (2a, 2b) and close the connection of the second chamber (2b) to the exhaust manifold (8), thereby allowing the selective passage of flue gases preferably at high pressure from the second to the first chamber .   5. Engine according to any one of claims 1 to 4 characterized in that the first exhaust gas control means (7a) comprises: either an exhaust valve selectively connecting the first chamber to the exhaust manifold and a first valve selectively connecting the first chamber to the second; a first three-way valve having a burned gas inlet connected to the first chamber, a first exhaust outlet selectively connected to the exhaust manifold and a first flue gas outlet selectively connecting the first chamber to the second, this three-way valve being adapted so that in the first burned gas supply configuration, the burned gas inlet is only connected to the first burned gas outlet.   6. Engine according to any one of claims 1 to 5, characterized in that the means for supplying burned gases selectively connecting the first and second chambers to each other comprises a first connecting pipe for conducting the flue gases from the first to the second chamber and a non-return means connected to the first conduit and adapted to allow only the passage of flue gas from the first to the second chamber.   7. Motor according to claim 6, characterized in that the motor comprises a yoke in which the connecting duct (11) is integrated.   8. Motor according to any one of claims 1 to 7 characterized in that it comprises recirculation means (12) selectively connecting the exhaust manifold to at least one of the chambers and including first control means of flow to recycle a portion of the exhaust manifold exhaust gases to at least one of the chambers.   An injection method for a heat engine (1), such as a direct injection diesel engine, comprising in particular first and second combustion chambers (2a, 2b), first and second fuel injection means ( 3a, 3b) for respectively injecting fuel into the first and second chambers (2a, 2b), first and second intake means (4a, 4b) to admit respectively and selectively in the first and second chambers (2a, 2b ), a gaseous oxidant containing air, first exhaust gas control means (7a) selectively connecting the first chamber to an exhaust manifold for selectively allowing the exhaust of flue gases out of the combustion chamber. first chamber (2a), a means for supplying burnt gases selectively connecting the first and second chambers to each other, the injection method being characterized in that it comprises: a first stage in which one creates in the first chamber the conditions of a combustion by injecting fuel and an oxidizer, the combustion producing flue gas; a second step subsequent to the first in which at least a portion of the flue gases produced during the first step are injected into the second chamber, at least partially closing, the selective passage of the flue gases from the first chamber to the collector of exhaust and then communicating the first chamber and the second through said means for supplying burnt gas, thus enabling the second chamber to be supplied with burnt gases, preferably at high pressure.