Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/38—Controlling fuel injection of the high pressure type
  • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
  • F02D41/402—Multiple injections
  • F02D41/403—Multiple injections with pilot injections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/30—Controlling fuel injection
  • F02D41/38—Controlling fuel injection of the high pressure type
  • F02D41/40—Controlling fuel injection of the high pressure type with means for controlling injection timing or duration
  • F02D41/402—Multiple injections
  • F02D41/405—Multiple injections with post injections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/021—Introducing corrections for particular conditions exterior to the engine
  • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
  • F02D41/024—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to increase temperature of the exhaust gas treating apparatus
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D41/00—Electrical control of supply of combustible mixture or its constituents
  • F02D41/02—Circuit arrangements for generating control signals
  • F02D41/021—Introducing corrections for particular conditions exterior to the engine
  • F02D41/0235—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus
  • F02D41/027—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus
  • F02D41/029—Introducing corrections for particular conditions exterior to the engine in relation with the state of the exhaust gas treating apparatus to purge or regenerate the exhaust gas treating apparatus the exhaust gas treating apparatus being a particulate filter
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/40—Engine management systems

Definitions

• the invention relates to a method for injecting fuel into an internal combustion engine cylinder in which one or more pre-injections, one or more main injections at the top dead center of combustion, an injection after and one or more are carried out. post-injections.
• Diesel in the so-called normal injection phase whose exhaust line is equipped with a catalyst, a particulate filter and a NOx trap can be broken down into three phases:
• a pilot injection is carried out or pre injection.
• This phase comprises one to two injections phased between 40 0 V and 20 ° V (V for crankshaft) before the top dead center of combustion.
• These pilot injections primarily reduce combustion noise but contribute in part to the dilution of fuel in the engine oil.
• a main injection is made, also called "hand injection".
• This phase comprises only a single phase injection at the top dead point combustion.
• the main injection serves essentially to ensure the load of the engine. She is the main source of NOx and particulate emissions. It generates little combustion noise and little dilution.
• a third phase an injection is performed after ("after-injection").
• This phase comprises only one injection phased between 10 ° V and 30 0 V after the top dead point combustion.
• This injection is useful to restart combustion during relaxation and reduce smoke emissions by post-oxidation of soot. It generates little combustion noise but can contribute slightly to the dilution of the fuel in the oil.
• post ⁇ injection This phase comprises from one to three phase injections after the injection after and therefore well beyond the high combustion dead point, typically between 60 ° V and 100 0 V after top dead center.
• the amount of fuel injected practically does not participate in the combustion in the cylinder; it goes directly to the exhaust and, via oxidation in the catalyst, it facilitates the initiation of the regeneration phases in the particulate filter and in the NOx trap.
• the post-injections contribute strongly to the increase of the dilution of the fuel in the oil because they are phased late in the cycle and directly impact the cylinder.
• the main sources of fuel dilution in the engine oil are post-injections and pre-injections.
• US 2003/0033 800 a method of regenerating a particle filter for a diesel engine having a common rail injection system.
• This system allows a main injection, a first pre-injection preceding the main injection; a second pre-injection preceding the main injection and following the first pre-injection; a first post-injection following the main injection; and a second post-injection following the first post-injection is performed at the escape stroke.
• the post-injections can be performed with a late phasing that can reach 360 0 V compared to the top dead point combustion.
• this device does not prevent the dilution of the fuel in the oil during the pre-injections.
• the present invention specifically relates to a method of injecting fuel into an internal combustion engine cylinder which overcomes these disadvantages.
• the fuel injection or post-injections are performed just before the top dead center of the intake and exhaust valves.
• the pre-injection (s) are made 10 0 V after the top dead center of the intake and exhaust valves.
• the one or more post-injections are performed 10 0 V before the upper dead center of crossing of the intake and exhaust valves.
• the pre-injection (s) and the post-injection (s) are carried out in the form of a single injection which groups together the pre-injection (s) and the post-injection (s) in a single injection which is performed just after the top dead center crossover intake and exhaust valves.
• a variable distribution system type of offset is used to adjust the amount of fuel that goes to the exhaust.
• the intake and exhaust distribution laws are shifted in the direction of admission so as to obtain an increase in the fuel quantity of the post-injection and a reduction in the amount of fuel. pre injection fuel.
• the intake and exhaust distribution laws are shifted towards the exhaust so as to obtain a reduction in the fuel quantity of the post-injection and an increase in the fuel quantity of the fuel. pre injection.
• FIG. 1A is a diagram showing the normal injection mode of a diesel engine according to the prior art
• Fig. 1B is an enlarged view of a portion of Fig. 1A
• - Figure 2A is a diagram showing the injection for the regeneration mode of a diesel engine according to the prior art
• Figure 2B is an enlarged view of a portion of Figure 2A;
• FIG. 3A is a diagram showing the normal injection mode of a diesel engine according to the present invention
• Figure 3B is an enlarged view of a portion of Figure 3A;
• FIG. 4A is a diagram showing the injection for the regeneration mode of a diesel engine according to the present invention
• Figure 4B is an enlarged view of a portion of Figure 4A
• Figure 5A is a variant of the injection mode for the regeneration mode shown in Figure 4A
• Figure 5B is an enlarged view of a portion of Figure 5A
• Figure 6 is a first sub-variant of the injection device shown in Figures 5A and 5B;
• Figure 7 is a second sub-variant of the injection device shown in Figures 5A and 5B.
• FIGS. 1A and 1B show an injection scheme according to the prior art of a diesel engine for the normal injection mode, that is to say an injection outside the regeneration phases.
• a main injection 4 and an injection after 6 are performed in each cylinder of the internal combustion engine.
• the pre-injection or pre-injections are carried out at 30 ° to 40 ° C. before the high combustion dead point.
• the main injection is centered on the top dead point combustion and the injection after is located about 30 0 V after the top dead point combustion.
• the pre-injection (s) are located in an unfavorable zone for the dilution or the limit of this zone.
• the main injection is located in the center of a favorable area for dilution and the after injection is located just on the boundary between the favorable zone for dilution and an unfavorable zone for dilution (substantially 30 0 V).
• FIG. 1A Also shown in FIG. 1A is the representation of the law of emergence of the exhaust valve 10 and the law of emergence of the intake valve 12.
• the lifting of the exhaust valve extends substantially from 135 ° to 405 ° while the law of the lifting of the intake valve extends substantially from 315 ° to 585 °.
• the two curves intersect and there is a range of rotation of the crankshaft during which the intake and exhaust valve are open simultaneously. This range extends substantially 90 ° rotation of the crankshaft.
• the simultaneous opening of the intake and exhaust valves takes place when the piston is at the top dead center. There are indeed two top dead spots per cycle namely respectively the top dead point combustion at 0 0 V and the top dead center crossing at 360 0 V.
• FIGS. 2A and 2B show a prior art injection scheme of a diesel engine for the regeneration mode of the particulate filter.
• This diagram is identical to FIGS. 1A and 1B except for one or more additional injections of post-injections 14 (3 in the example represents). These injections take place respectively at 60 °, 80 ° and 100 °. They are therefore all placed in an unfavorable zone for the dilution of the fuel in the engine oil.
• FIGS. 3A and 3B show an injection diagram of a diesel engine according to the present invention for the normal injection mode, that is to say outside the regeneration phases.
• This scheme resembles that of Figures IA and IB. However, it differs in that the two pre- injections 2 have been moved. They are now just after the top dead center at the intersection of the intake and exhaust valves that is just after 360 ° crankshaft angle. In the example there are two pre-injections, but there could be more, for example three or more. As can be seen in FIG. 3A, the two pre-injections 16 are located in a favorable zone for dilution.
• FIGS. 4A and 4B show an injection diagram of a diesel engine according to the present invention for the "regeneration" mode.
• these postmissions which are located at about 10 0 V to 40 0 V before the top dead center, are located in a favorable zone for the dilution of the fuel in the oil present on the fuel. barrels of engine cylinders.
• the pre-injections are located after the post-mections because the pre-mjections are relative to the next engine cycle while the post-mjections are valid for the present engine cycle.
• FIGS. 5A and 5B show a variant of the injection scheme of a diesel engine according to the present invention shown in FIG. 4A and 4B.
• the pre-injections 16 and the post-mections 18 were grouped together in a single larger injection. 20.
• Injection 20 is located just after the top dead center of the intake and exhaust valves, that is to say just after 360 0 V.
• this single injection 20 is entirely located in a favorable zone for dilution, which extends substantially from 300 0 V to 420 ° V.
• variable timing system is a system that varies the position of the camshaft which controls the intake and exhaust valves and thus the valve openings and closures as well as the opening times.
• WT shifters also called "WT" for variable valve timing. These systems consist of shifting the camshafts that is to say to change the openings and closings of the valves without changing the duration during which the valve is opened or closed.
• FIG. 7 shows an alternative embodiment of the diagram of FIG. 6.
• the law of the lifting of the exhaust valve and the law of the lifting of the intake valve are shifted towards the the value of this offset is approximately 45 °.
• the angular position of the grouped injection 20 is not changed. It is always right after the top dead center of the intake and exhaust valves, that is to say 360 0 V. However, since the exhaust valve is closed at the moment when begins fuel injection, no fraction of this fuel is delivered to the exhaust. The entire fuel is a pre-injection.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Applications Claiming Priority (2)

Publications (1)

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Cited By (1)

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Family Cites Families (3)

• 2007
  • 2007-09-20 FR FR0757704A patent/FR2921428B1/fr active Active
• 2008
  • 2008-07-09 EP EP08832490A patent/EP2193268A2/de not_active Withdrawn
  • 2008-07-09 WO PCT/FR2008/051281 patent/WO2009037405A2/fr active Application Filing

Non-Patent Citations (1)

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