CN101451474A - Fuel supply apparatus for internal combustion engine - Google Patents
Fuel supply apparatus for internal combustion engine Download PDFInfo
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- CN101451474A CN101451474A CNA2008101903058A CN200810190305A CN101451474A CN 101451474 A CN101451474 A CN 101451474A CN A2008101903058 A CNA2008101903058 A CN A2008101903058A CN 200810190305 A CN200810190305 A CN 200810190305A CN 101451474 A CN101451474 A CN 101451474A
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- 239000000446 fuel Substances 0.000 title claims abstract description 993
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 111
- 238000002347 injection Methods 0.000 claims description 582
- 239000007924 injection Substances 0.000 claims description 582
- 239000007921 spray Substances 0.000 claims description 88
- 239000002828 fuel tank Substances 0.000 claims description 39
- 238000007599 discharging Methods 0.000 claims description 29
- 238000012544 monitoring process Methods 0.000 claims description 15
- 238000012806 monitoring device Methods 0.000 claims description 7
- 230000003213 activating effect Effects 0.000 claims description 3
- 239000002826 coolant Substances 0.000 abstract description 37
- 230000007246 mechanism Effects 0.000 description 42
- 238000010304 firing Methods 0.000 description 25
- 238000005507 spraying Methods 0.000 description 19
- 238000005086 pumping Methods 0.000 description 18
- 238000001816 cooling Methods 0.000 description 13
- 239000003921 oil Substances 0.000 description 12
- 238000001514 detection method Methods 0.000 description 10
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- 230000002349 favourable effect Effects 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 5
- 230000001351 cycling effect Effects 0.000 description 4
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- 230000008569 process Effects 0.000 description 4
- 230000003068 static effect Effects 0.000 description 4
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
- 239000000567 combustion gas Substances 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000005764 inhibitory process Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
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- 238000011144 upstream manufacturing Methods 0.000 description 1
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- Fuel-Injection Apparatus (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
The invention relates to a fuel supply apparatus for an internal combustion engine. The engine ECU executes a program including the step (S100) of detecting an engine coolant temperature, the step (S110) of detecting an engine speed and an engine load, the step (S120) of estimating a temperature at a tip end of an in-cylinder injector based on the engine coolant temperature, the engine speed and the engine load, and, when the temperature at the tip end is greater than a guaranteed temperature (YES in S130), the step (S140) of calculating a drive duty of a high-pressure fuel pump that ensures a decrease of the temperature at the tip end of the in-cylinder injector to the guaranteed temperature, and the step (S160) of controlling the high-pressure fuel pump using the drive duty.
Description
The application is for dividing an application, and the applying date of original application is on 09 06th, 2005, and application number is No.200580034454.X, and denomination of invention is " fuel facility that is used for internal-combustion engine ".
Technical field
The present invention relates to be used for only having the fuel facility of the internal-combustion engine of the in-cylinder injection device that injects fuel into cylinder, perhaps be used for having the fuel facility of the internal-combustion engine of the in-cylinder injection device of intake manifold of injecting fuel into or suction port and manifold injection device.More specifically, the present invention relates to be used for be suppressed at the technology of the sedimental formation of spray-hole of in-cylinder injection device.
Background technique
A kind of fuel injection apparatus that is used to be provided with the internal-combustion engine of in-cylinder injection device and manifold injection device and is used to control two fuel injection ratio between the sparger has for example been described in Japanese Patent Laid Open Publication 07-103048.
In the equipment that Japanese Patent Laid Open Publication 07-103048 describes, be connected to common fuel delivery pipe corresponding to the in-cylinder injection device of each cylinder.Fuel-supply pipe is via allowing the safety check towards delivery pipe flows to be connected to by oil-engine driven high pressure fuel pump.High pressure fuel pump is provided with solenoid valve, and opening/closing opportunity of control electromagnetic valve is to adjust from the fuel quantity of high pressure fuel pump discharging.
In this existing equipment, at the depression degree (being the load of internal-combustion engine) of accelerator pedal high capacity duration of work greater than the stipulated standard value, at the early stage of aspirating stroke only from the manifold injection device towards tuned port injection fuel.At above-mentioned high capacity duration of work, solenoid valve keeps standard-sized sheet, stops thus from the supply of fuel of high pressure fuel pump to delivery pipe.
Also known a kind of internal-combustion engine that is provided with manifold injection device (being used for injecting fuel into intake manifold) and in-cylinder injection device (being used for injecting fuel into constantly the firing chamber), wherein when engine loading is lower than default load, stop to spray, and be higher than when presetting load from manifold injection device burner oil when engine loading from the fuel of manifold injection device.In this internal-combustion engine, will with the fuel that sprays from two spargers be predefined for the function of engine load with corresponding total emitted dose, and along with the rising of engine load increases total emitted dose.
The in-cylinder injection device is installed into makes its spray-hole directly to the combustion chamber openings of internal-combustion engine.Its general is directly injected in the cylinder by the fuel of petrolift supercharging.Inject fuel directly into the later stage burner oil that in-cylinder injection device in the cylinder of internal-combustion engine is provided in compression stroke and carry out High Accuracy Control, to improve fuel efficiency etc. with admixture to the empty burning mixt in the cylinder.In the in-cylinder injection device that injects fuel directly into like this in the cylinder, fuel pressure is higher, and this causes noise and vibration in the high-pressure fuel system.Particularly, during low loaded work piece (for example, idling), internal-combustion engine only can produce lower noise, and feasible thus noise and the vibration from high-pressure fuel system becomes obvious.
In addition, (being provided for the spray-hole place of burner oil) is projected in the firing chamber because the in-cylinder injection device is arranged to its end, so accumulate sediments easily in spray-hole, this fuel that can lead to errors sprays.More specifically, the spray-hole in the tail end of in-cylinder injection device is arranged in the firing chamber, can accumulate in spray-hole at hot environment deposit thing, hinders the fuel that sprays desired amount thus.The temperature of in-cylinder injection device tail end is subjected to from the very big influence of the heat of combustion gas reception.It also is subjected to from the heat of cylinder head reception, diffuses to the heat of fuel and the influence of other factors.Think along with temperature rising sediments can make the spray-hole constriction gradually.
Japanese Patent Laid Open Publication 09-021369 has disclosed a kind of fuel injection control apparatus that is used to have the internal-combustion engine of this high-pressure fuel supply system, the smooth combustion when being intended to realize low loaded work piece.This fuel injection control apparatus that is used for internal-combustion engine comprises the fuel pressurizing device that is used for fuel pressure boost, is used for spraying in a controlled manner by the fuel injection system of the fuel of fuel pressurizing device supercharging, the pressure change device that is used to detect the external loading detection device of the load that is applied to motor from the outside and is used for reducing the pressure of fuel pressurizing device when being lower than specified value by the detected load of external loading detection device by open/closed valve.
According to the above-mentioned fuel injection control apparatus that is used for internal-combustion engine, the external loading detection device detects the current load that is applied to motor from the outside, and checkout value is output to the pressure change device.The pressure change device is applied to from the pressure of the fuel of fuel injection system injection according to being set by the detected value of external loading detection device by fuel pressurizing device.Fuel injection system sprays the fuel that has been pressurized according to setting pressure then.When the external loading detection device detected the load that is applied to motor from the outside and is not more than specified value, the pressure change device was just controlled to reduce by the fuel pressurizing device applied pressure, reduces the pressure of the fuel that is supplied to fuel injection system thus.Compared to the fuel pressure condition with higher, along with fuel pressure reduces, the valve opening speed of fuel injection system quickens.Therefore, can shorten valve and open the required time fully, and be stabilized in the short fuel quantity that sprays the period injection.
In-cylinder injection device in the sparger is mounted to cylinder head, makes its spray-hole opening to the firing chamber.This means that compared to the manifold injection device near the part its spray-hole suffers high temperature easily.When near the part spray-hole of in-cylinder injection device was born high temperature, pin, sheet and other parts can expand, and caused fuel injection amount to be lower than its desired value.The problems referred to above are with even more serious when spraying only carrying out fuel by the manifold injection device, and this is because the fuel in the in-cylinder injection device moves hardly, and fuel and in-cylinder injection device all bear high temperature.
Therefore, after and then spraying the fuel injection that switches to by the in-cylinder injection device from the fuel by the manifold injection device, because the in-cylinder injection device expands, fuel injection amount becomes immediately less than its desired value (although being temporary transient).This causes rarer air fuel ratio inevitably.
Simultaneously, the fuel injection control apparatus of in Japanese Patent Laid Open Publication 09-021369, describing that is used for internal-combustion engine, fuel pressure reduces during low loaded work piece, thinks and can reduce noise and the vibrations (NV) that the fuel supply pressure system causes because of high pressure like this.In addition, in low loaded work piece, can reduce the fuel quantity that sprays from the in-cylinder injection device, perhaps even can stop to spray from the fuel of in-cylinder injection device.Can only come burner oil to guarantee more uniform supply of fuel, perhaps can increase the fuel quantity that sprays from the manifold injection device by the manifold injection device.
But, if reduce the fuel quantity that sprays from the in-cylinder injection device or even stop to spray from its fuel because the in-cylinder injection device is by the fuel cooling by it, so the temperature of the tail end of in-cylinder injection device can raise.In this case, the temperature of spray-hole that is positioned at the tail end of in-cylinder injection device will raise, and sediments will block spray-hole gradually.
Summary of the invention
Carried out the present invention to solve above-mentioned existing issue.The object of the present invention is to provide a kind of fuel facility that is used for internal-combustion engine, it can suppress the variation of the fuel injection amount of in-cylinder injection device, and can keep good combustion regime and favourable exhaust emissions.
Another object of the present invention is to provide a kind of fuel facility that is used for internal-combustion engine, and it can be suppressed at sedimental formation in the spray-hole of in-cylinder injection device.
Equipment according to an aspect of the present invention is a kind of fuel facility that is used for internal-combustion engine, described internal-combustion engine has second fuel injection mechanism that is used for injecting fuel into first fuel injection mechanism of cylinder and is used for injecting fuel into intake manifold, described fuel facility comprises: the monitoring temperature unit, and it is used to monitor the temperature of the tail end of described first fuel injection mechanism; And control unit, it is used for making when temperature in the described tail end that is obtained by described monitoring temperature unit is not less than reference temperature the high-pressure fuel system institute circuit fuel quantity by supplying fuel to described first fuel injection mechanism to increase.
According to the present invention, when near the temperature the spray-hole of the in-cylinder injection device tail end that is regarded as first fuel injection mechanism becomes reference temperature or when higher, increases by in-cylinder injection fuel system (it comprises the in-cylinder injection delivery pipe that the in-cylinder injection device is installed) institute's circuit fuel quantity.For example, under the situation of only carrying out the fuel injection, when not coming circulating fuel, just begin circuit supply of fuel by in-cylinder injection fuel system institute by the in-cylinder injection fuel system by the manifold injection device that is regarded as second fuel injection mechanism.Not only from the manifold injection device but also relatively small amount ground carry out from the in-cylinder injection device during by in-cylinder injection fuel system circulating fuel, increasing institute's circuit fuel quantity under the situation that fuel sprays.By increasing institute's circuit fuel quantity, the temperature that can suppress to be supplied to the fuel of in-cylinder injection device rises, and fuel can cool off the in-cylinder injection device, particularly near the part its spray-hole.Therefore, suppress near the expansion of the part spray-hole of in-cylinder injection device, can accurately control the fuel quantity in the firing chamber that is ejected into internal-combustion engine, and therefore can keep good fuel state and favourable exhaust emissions.
Preferably, the temperature of described tail end is monitored in described monitoring temperature unit according to the fuel temperature in the described high-pressure fuel system.
According to the present invention, monitor near the temperature the spray-hole of in-cylinder injection device tail end according to the fuel temperature in the high-pressure fuel system that supplies fuel to the in-cylinder injection device.The in-cylinder injection device is filled with fuel, so near the temperature the temperature of fuel and the spray-hole each other about equally.Therefore, can accurately monitor near the spray-hole temperature by the temperature of fuel in the monitoring in-cylinder injection device fuel system.In addition, in the time can sharedly being present in fuel temperature detecting sensor in the in-cylinder injection fuel system and realizing above-mentioned purpose, can further simplify its structure.
Preferably, described monitoring temperature unit is according to the coolant temperature of described internal-combustion engine with only estimate described fuel temperature by the endurance of the described second fuel injection mechanism alone jetting fuel.
According to the present invention, according to the coolant temperature of internal-combustion engine and only carry out endurance that fuel sprays and estimate to supply fuel to the temperature of fuel in the high-pressure fuel system of in-cylinder injection device by the manifold injection device that is regarded as second fuel injection mechanism.The coolant temperature of internal-combustion engine is corresponding to engine temperature, and can estimate that the fuel temperature of high-pressure fuel system also will raise along with coolant temperature (engine temperature) raises.In addition, when the duration of charge that is only undertaken by the manifold injection device is longer, the supply of fuel of in-cylinder injection device is stopped for a long time, can be estimated that thus the temperature of in-cylinder injection device will raise under the situation of the high-temperature fuel of stagnating.Therefore, can estimate fuel temperature with highi degree of accuracy according to coolant temperature and duration of charge.
Preferably, described control unit is determined period of carrying out fuel cycle under the circuit fuel quantity increases making the situation according to the described fuel temperature that is obtained by described monitoring temperature unit.
According to the present invention, in according to high-pressure fuel system, during the determined period of fuel temperature, make the fuel cycle of increase.By such setting, for example compared in situation by coming circulating fuel by high-pressure fuel system during only spraying the whole period that drives internal-combustion engine from the independent fuel of manifold injection device, the driving loss that causes because of periodic duty can be reduced, the in-cylinder injection device can be cooled off effectively thus.
Increase institute's circuit fuel quantity when preferably, the temperature of described control unit in described tail end is not less than described reference temperature and when only carrying out the fuel injection by described second fuel injection mechanism.
According to the present invention,, increase institute's circuit fuel quantity when near the temperature the spray-hole is not less than reference temperature and is only carrying out fuel when spraying from the manifold injection device.By such setting, for example compared to by only spraying the situation of coming circulating fuel by high-pressure fuel system during driving the whole period of internal-combustion engine from the fuel of manifold injection device, the driving loss that causes because of periodic duty can be reduced, therefore the in-cylinder injection device can be cooled off effectively.
Preferably, described high-pressure fuel system comprise described first fuel injection mechanism, described first fuel injection mechanism be installed to its delivery pipe, be used for from the fuel tank fuel supplying low-pressure fuel pump, be used for from the further supercharging of the fuel of described low-pressure fuel pump and with high-pressure fuel supply to the high pressure fuel pump of described delivery pipe, be used for discharging the release channel of fuel and being arranged on the safety valve of described release channel to described fuel tank from described delivery pipe.Described control unit increases institute's circuit fuel quantity by opening described safety valve and increasing from the described fuel under high pressure amount of described high pressure fuel pump supply.
According to the present invention, from fuel tank by the low-pressure fuel pump supplied fuel before being supplied to the in-cylinder injection delivery pipe by the high pressure fuel pump supercharging.When the safety valve that is arranged on the release channel place was opened, fuel was released into fuel tank from the in-cylinder injection delivery pipe.Realized the circulation of fuel like this.When the amount of the fuel under high pressure of supplying from high pressure fuel pump increased, institute's circuit fuel quantity increased.Therefore, by making fuel under high pressure circulation, can when spraying, the fuel that switches to by the in-cylinder injection device carry out fuel immediately and spray spraying from fuel by the manifold injection device.In addition, by making the fuel under high pressure circulation, compared to making low-pressure fuel circuit situation, the more substantial fuel that can circulate quickens the cooling to the in-cylinder injection device thus.In addition, by making the fuel under high pressure circulation, even under in-cylinder injection device injection small amount of fuel situation, also can carry out fuel cycle.Therefore, can suppress near the expansion of the part spray-hole of in-cylinder injection device, guarantee that thus suitable fuel sprays.
Preferably, described high-pressure fuel system comprise described first fuel injection mechanism, described first fuel injection mechanism be installed to its delivery pipe, be used for from the fuel tank fuel supplying low-pressure fuel pump, be used for from the further supercharging of the fuel of described low-pressure fuel pump and with high-pressure fuel supply to the high pressure fuel pump of described delivery pipe, be used for discharging the release channel of fuel and being arranged on the safety valve of described release channel to described fuel tank from described delivery pipe.Described control unit increases institute's circuit fuel quantity by opening described safety valve and increasing from described low-pressure fuel pump supplied fuel amount when inhibition is carried out supercharging by described high pressure fuel pump to fuel.
According to the present invention, under not by the situation of high pressure fuel pump supercharging, be provided to the in-cylinder injection delivery pipe by the low-pressure fuel pump supplied fuel as low-pressure fuel from fuel tank.Therefore, when the safety valve that is arranged on the release channel place was opened, fuel was released into fuel tank from the in-cylinder injection delivery pipe.Realized the circulation of fuel like this.Therefore, by making low-pressure fuel circulation, can carry out fuel cycle and do not apply bigger load to internal-combustion engine.
Equipment according to another aspect of the present invention is a kind of fuel facility that is used for internal-combustion engine, described internal-combustion engine has second fuel injection mechanism that is used for injecting fuel into first fuel injection mechanism of cylinder and is used for injecting fuel into intake manifold, described fuel facility comprises: the pressure monitor unit, and it is used for monitoring the pressure of the described first fuel injection mechanism fuel; Releasing unit, it is used for the fuel that described first fuel injection mechanism is installed in its delivery pipe is outwards discharged; And control unit, it is used for activating described releasing unit to discharge the fuel in the described delivery pipe when the described fuel pressure that is obtained by described pressure monitor unit is not less than reference pressure, reduce described fuel pressure thus, and be used for becoming and stop described releasing unit when being used to make described first fuel injection mechanism to carry out critical pressure that fuel sprays with minimum injection limit in described fuel pressure.
According to the present invention, when the fuel pressure in the in-cylinder injection device that is regarded as first fuel injection mechanism becomes when being equal to or greater than reference pressure, just outwards in the release cylinder sparger be installed to fuel in its in-cylinder injection delivery pipe.By such release fuel, can reduce the pressure of the fuel that just is being provided to the in-cylinder injection device.When fuel pressure reaches when being used for first fuel injection mechanism and carrying out critical pressure that fuel sprays with minimum injection limit, just stop release to fuel.Therefore, by guaranteeing to be used for carrying out the critical pressure of fuel injection, can easily carry out fuel and spray with minimum injection limit with minimum injection limit.In addition, along with fuel pressure increases, fuel temperature also raises.Discharge the temperature that fuel can suppress just to be provided to the fuel of in-cylinder injection device and raise, and near the part cooling the in-cylinder injection device, particularly its spray-hole.Therefore, suppress near the expansion of the part spray-hole of in-cylinder injection device, and can accurately control the fuel quantity of the firing chamber that is injected into internal-combustion engine, thereby kept good combustion regime and favourable exhaust emissions.
Preferably, described releasing unit comprise the low-pressure fuel pump that is used for from the fuel tank fuel supplying, be used for from the further supercharging of the fuel of described low-pressure fuel pump and with high-pressure fuel supply to the high pressure fuel pump of described delivery pipe, be used for discharging the release channel of fuel and being arranged on the safety valve of described release channel to described fuel tank from described delivery pipe.Become when being equal to or higher than reference pressure in the described fuel pressure that is obtained by described pressure monitor unit, described control unit is opened described safety valve discharging the fuel in the described delivery pipe, and activate described high pressure fuel pump reach specified time period with high-pressure fuel supply to described delivery pipe.After the scheduled time slot process, it is supplied to described delivery pipe with low-pressure fuel from described low-pressure fuel pump.Reach when being used for carrying out described critical pressure that fuel sprays with minimum injection limit in the described fuel pressure that is obtained by described pressure monitor unit, described control unit is closed described safety valve to stop the release of fuel.
According to the present invention, when the fuel pressure in the in-cylinder injection device becomes when being equal to or greater than reference pressure, just outwards sparger is installed to fuel in its in-cylinder injection delivery pipe in the release cylinder, and will reach specified time period from high-pressure fuel supply to the in-cylinder injection delivery pipe of high pressure fuel pump.After the scheduled time slot process, circulation reaches the critical pressure that is used for carrying out with minimum injection limit the fuel injection from the low-pressure fuel of low-pressure fuel pump until fuel pressure.Therefore, circulate,, the cooling of the fuel that is supplied to the in-cylinder injection device and the cooling of in-cylinder injection device are quickened compared to the situation of circulation low-pressure fuel by at first making fuel under high pressure.
Preferably, described releasing unit comprise the low-pressure fuel pump that is used for from the fuel tank fuel supplying, be used for from the further supercharging of the fuel of described low-pressure fuel pump and with high-pressure fuel supply to the high pressure fuel pump of described delivery pipe, be used for discharging the release channel of fuel and being arranged on the safety valve of described release channel to described fuel tank from described delivery pipe.When the described fuel pressure that is obtained by described pressure monitor unit was not less than reference pressure, described control unit was opened described safety valve to discharge the fuel in the described delivery pipe and low-pressure fuel is supplied to described delivery pipe from described low-pressure fuel pump.Become when being used for carrying out described critical pressure that fuel sprays with minimum injection limit in the described fuel pressure that is obtained by described pressure monitor unit, described control unit is closed described safety valve to stop the release of fuel.
According to the present invention, when the fuel pressure in the in-cylinder injection device becomes when being equal to or higher than reference pressure, outwards sparger is installed to fuel in its in-cylinder injection delivery pipe in the release cylinder, and low-pressure fuel is supplied to the in-cylinder injection delivery pipe from low-pressure fuel pump.By low-pressure fuel is circulated in this way, the fuel pressure in the in-cylinder injection device can be reduced to the critical pressure that is used for carrying out the fuel injection rapidly with minimum injection limit.
Equipment according to a further aspect in the invention is a kind of fuel facility that is used for internal-combustion engine, described internal-combustion engine has first fuel injection mechanism that is used for injecting fuel into cylinder and second fuel injection mechanism that is used for injecting fuel into intake manifold, and the high-pressure fuel system that wherein is used to supply fuel to described first fuel injection mechanism comprises high pressure fuel pump.Described fuel facility comprises: be used for controlling described fuel injection mechanism according to the situation of described internal-combustion engine demand and carry out the injection control unit that fuel sprays with the one or both of utilizing described first and second fuel injection mechanism; With the control unit that is used to control described high pressure fuel pump.Even described control unit is controlled described high pressure fuel pump and is made in the zone that described first fuel injection mechanism stops also from described high pressure fuel pump fuel supplying.
According to the present invention, even spray the zone that stops, also from supply of fuel being entered the high pressure fuel pump discharge fuel of in-cylinder injection device at fuel from the in-cylinder injection device that is regarded as first fuel injection mechanism.Be supplied to the in-cylinder injection device from the fuel of high pressure fuel pump discharging via high-pressure delivery pipe.Under the normal conditions,, fuel can be supplied to in-cylinder injection device (for example, electromagnetic relief valve stays open) from high pressure fuel pump via high-pressure delivery pipe not from the zone of in-cylinder injection device burner oil.On the contrary, according to the present invention, fuel is transported to the in-cylinder injection device, cools off the end of in-cylinder injection device thus.When having cooled off when terminal, also cooled off the spray-hole that is arranged to project to the firing chamber of in-cylinder injection device, suppressed sedimental generation thus.Place, end in high-pressure delivery pipe for example is provided with safety valve, and fuel is back to fuel tank by safety valve.Therefore, can be provided for the fuel facility of internal-combustion engine, it can suppress sedimental generation (otherwise sediments will be accumulated in the spray-hole of in-cylinder injection mechanism).
Preferably, fuel facility also comprises the estimation unit of the temperature of the tail end that is used to estimate described first fuel injection mechanism, and described control unit is controlled described high pressure fuel pump according to the temperature of described tail end.
According to the present invention, estimate the temperature of the tail end of in-cylinder injection device according to the working state of internal-combustion engine.Be confirmed as making that from the fuel quantity of high pressure fuel pump discharging the estimation temperature of tail end can not reach the higher temperature that allows sediments to form.Can cool off the in-cylinder injection device by fuel, can suppress sedimental generation thus.
Equipment according to a further aspect in the invention is a kind of fuel facility that is used for internal-combustion engine, described internal-combustion engine has first fuel injection mechanism that is used for injecting fuel into cylinder and second fuel injection mechanism that is used for injecting fuel into intake manifold, and the high-pressure fuel system that wherein is used to supply fuel to described first fuel injection mechanism comprises high pressure fuel pump.Described fuel facility comprises: be used for controlling described fuel injection mechanism according to the situation of described internal-combustion engine demand and carry out the injection control unit that fuel sprays with the one or both of utilizing described first and second fuel injection mechanism; Be used to estimate the estimation unit of temperature of the tail end of described first fuel injection mechanism; With the control unit that is used to control described high pressure fuel pump.Even described control unit is controlled described high pressure fuel pump and is made also to come from described high pressure fuel pump fuel supplying according to the temperature of described tail end when the fuel quantity that sprays from described first fuel injection mechanism reduces.
According to the present invention, even the zone that the fuel quantity that sprays from the in-cylinder injection device that is regarded as first fuel injection mechanism reduces, also spray the fuel quantity that temperature calculated according to the tail end of in-cylinder injection device from the high pressure fuel pump that supplies fuel to the in-cylinder injection device.That is,, can not reduce from high pressure fuel pump supplied fuel amount even the fuel quantity that sprays from the in-cylinder injection device reduces yet, thus via high-pressure delivery pipe to a large amount of fuel of in-cylinder injection device supply.Under the normal conditions, from the zone of in-cylinder injection device burner oil, will not reduce the fuel quantity opportunity of late release electromagnetic relief valve (for example, by) that is supplied to the in-cylinder injection device from high pressure fuel pump via high-pressure delivery pipe.On the contrary, according to the present invention, a large amount of fuel are provided to the in-cylinder injection device, and associated fuel can be cooled off the end of in-cylinder injection device.When having cooled off when terminal, also cooled off the spray-hole that is arranged to project to the firing chamber of in-cylinder injection device, suppressed sedimental accumulating thus.In the in-cylinder injection device, control fuel pressure and injection duration are ejected in the firing chamber with the fuel with demand.Therefore, can be provided for the fuel facility of internal-combustion engine, it can suppress sedimental formation (otherwise sediments will be accumulated in the spray-hole of in-cylinder injection mechanism).
Preferably, the control of described control unit makes the temperature of described tail end become from the fuel quantity of described high pressure fuel pump discharging not to be higher than predetermined temperature.
According to the present invention, the fuel quantity that discharges from high pressure fuel pump is confirmed as making that the temperature of tail end will can not be higher than predetermined temperature, perhaps makes the temperature of tail end will can not become the higher temperature that allows sediments to form.Fuel can cool off the in-cylinder injection device to suppress sedimental formation.
Preferably, described estimation unit is estimated the temperature of described tail end according in temperature, engine speed and the load of described internal-combustion engine at least one.
According to the present invention, can accurately estimate the temperature of tail end according in the load of the engine speed of the temperature of internal-combustion engine, internal-combustion engine and internal-combustion engine at least one
Preferably, described first fuel injection mechanism is the in-cylinder injection device, and described second fuel injection mechanism is the manifold injection device.
According to the present invention, in-cylinder injection device that can be by being provided as first fuel injection mechanism respectively and prevent sedimental accumulating in the spray-hole of in-cylinder injection device as the manifold injection device of second fuel injection mechanism.
Description of drawings
Fig. 1 shows the schematic structure according to the fuel injection apparatus of the internal-combustion engine of the first embodiment of the present invention.
Fig. 2 is a flow chart, shows the control structure of the program that the ECU by the control gear of realizing first embodiment carries out.
Fig. 3 is a flow chart, shows the control structure of the program that the ECU by the control gear of realizing the second embodiment of the present invention carries out.
Fig. 4 is the sequential chart that the state of a control among second embodiment is shown.
Fig. 5 is the overview by the petrolic fuel system of the control gear control of a third embodiment in accordance with the invention.
Fig. 6 is the partial enlarged view of Fig. 5.
Fig. 7 shows from the relation between the temperature of the tail end of the fuel quantity of high pressure fuel pump discharging and in-cylinder injection device.
Fig. 8 is to use engine speed and the engine loading isothermal chart as the terminal temperature of the in-cylinder injection device of parameter.
Fig. 9 is a flow chart, shows the control structure of the program of being carried out by the Engine ECU of the control gear of realizing the 3rd embodiment.
Figure 10 to Figure 13 is the DI ratio chart of the motor that control gear was suitable for according to an embodiment of the invention.
Embodiment
Below with reference to accompanying drawing embodiments of the invention are described.Identical label represents to have the same section of same names and function, therefore will not repeat the description to it.In the following description, be used for the fuel injection apparatus of internal-combustion engine or the fuel facility that fuel system will be described as being used for internal-combustion engine.
(first embodiment)
Referring now to Fig. 1 and Fig. 2 the fuel injection apparatus that is used for internal-combustion engine according to first embodiment of the invention is described.In the present embodiment, use description to the fuel injection apparatus of six cylinder gasoline engines (as internal-combustion engine).
As shown in Figure 1, fuel injection apparatus comprises injecting fuel in the suction port 1 with low-pressure fuel 3 that sky burning mixt (it is provided to firing chamber 2) is provided and with fuel and directly is fed to high-pressure fuel supply system 4 in the firing chamber 2.Low-pressure fuel 3 and high-pressure fuel supply system 4 shared low pressure fuel passages 7 are supplied to low-pressure fuel pump 6 with fuel (hereinafter referred to as " low-pressure fuel ") from fuel tank 5 by this low pressure fuel passage 7.
Low-pressure fuel 3 comprises the suction port delivery pipe 8 that is connected to low pressure fuel passage 7, and six manifold injection devices 9 that are mounted to suction port delivery pipe 8.In low-pressure fuel 3, be ejected in the suction port 1 via manifold injection device 9 by the low-pressure fuel of low-pressure fuel pump 6 by low pressure fuel passage 7 supplies.
High-pressure fuel supply system 4 comprises the high pressure fuel pump 10 that is connected to low pressure fuel passage 7, from high pressure fuel pump 10 supplied fuel (being called " fuel under high pressure ") by its high pressure fuel passage 11 that flows, six in-cylinder injection devices 13 that are connected to the in-cylinder injection delivery pipe 12 of high pressure fuel passage 11 and are mounted to in-cylinder injection delivery pipe 12.In high-pressure fuel supply system 4, be ejected into the firing chamber 2 via in-cylinder injection device 13 from the fuel under high pressure of high pressure fuel pump 10 by high pressure fuel passage 11 supplies.
High pressure fuel pump 10 comprises cylinder 14, the piston 15 that moves back and forth in cylinder 14 and the pumping chamber 16 that is defined by cylinder 14 and piston 15.Piston 15 is according to the motion of the cam 18 that is mounted to exhaust cam shaft 17 and to-and-fro motion in cylinder 14.Pumping chamber 16 be connected to low pressure fuel passage 7 and high pressure fuel passage 11 both.
High pressure fuel pump 10 also comprises electromagnetic relief valve 19, and it is connected pumping chamber 16/disconnect with low pressure fuel passage 7.Electromagnetic relief valve 19 has o 20, and the voltage that is applied to o 20 is controlled to open/closed valve 19.Particularly, when o 20 was not switched on, electromagnetic relief valve 19 was opened by the thrust of disc spring 21, thus low pressure fuel passage 7 was connected to pumping chamber 16.When o 20 energisings, electromagnetic relief valve 19 opposing disc springs 21 cut out, and thus low pressure fuel passage 7 are disconnected with pumping chamber 16.
By the high pressure fuel pump 10 with said structure, when piston 15 moves on the direction of the volume of increase pumping chamber 16 (in suction stroke), electromagnetic relief valve 19 is opened so that low pressure fuel passage 7 is connected to pumping chamber 16.So the low-pressure fuel of supplying by low-pressure fuel pump 6 from fuel tank 5 is inhaled into pumping chamber 16 from low pressure fuel passage 7.Subsequently, when moving on piston 15 is reducing the direction of volume of pumping chamber 16 (in delivery stroke), electromagnetic relief valve 19 cuts out so that low pressure fuel passage 7 is disconnected with pumping chamber 16.So,, and the fuel under high pressure that obtains is delivered to high pressure fuel passage 11 to the fuel pressure boost in the pumping chamber 16.
High pressure fuel passage 11 is provided with safety check 22, and is connected to in-cylinder injection delivery pipe 12.Open safety check 22 from the fuel under high pressure of high pressure fuel pump 10, and be fed in the in-cylinder injection delivery pipe 12 via high pressure fuel passage 11.Do not use and can be used as safety check 22 by the valve of opening from the low-pressure fuel of low-pressure fuel pump 6 supplies.
Six in-cylinder injection devices 13 are mounted to in-cylinder injection delivery pipe 12, and the fuel under high pressure that is supplied to in-cylinder injection delivery pipe 12 is directly injected to the corresponding firing chamber 2 from each in-cylinder injection device 13.In addition, in-cylinder injection delivery pipe 12 is provided with the fuel pressure sensor 23 that is used to detect in-cylinder injection delivery pipe 12 mesohigh fuel pressures.To input to ECU (electronic control unit) 30 (will following described) by the fuel pressure that fuel pressure sensor 23 detects.
In addition, in-cylinder injection delivery pipe 12 is connected to fuel tank 5 via release channel 24.Release channel 24 is provided with electromagnetic valve 25 at the place, end that it is positioned at in-cylinder injection delivery pipe 12 those sides.Along with the voltage that is applied to o 26 is controlled, come opening/closing electromagnetic valve 25.When electromagnetic valve 25 was opened, the fuel under high pressure in the in-cylinder injection delivery pipe 12 was released into fuel tank 5, thus the fuel pressure in the in-cylinder injection delivery pipe 12 was remained on suitable level.
Be connected to the position of pumping chamber 16 at low pressure fuel passage 7, be connected with release channel 27, release channel 27 is provided with safety check 28.This release channel 27 is connected to release channel 24.When the fuel pressure in the low pressure fuel passage 7 raise because of having supplied excessive low-pressure fuel, safety check 28 was opened, and low-pressure fuel is released into fuel tank 5 by release channel 27 and 24.
Control the fuel injection apparatus with said structure by ECU 30, this ECU 30 plays control device (being made of CPU, ROM, RAM, ASIC, I/F and other various devices).The ROM storage of ECU 30 is as program one of various programs that are used for controlling combustion engine, that be used to control fuel injection apparatus.In addition, the ROM storage map of ECU 30 is in the figure with the coolant temperature of internal-combustion engine and only use manifold injection device 9 to carry out endurance that fuel sprays and in-cylinder injection delivery pipe 12 interior fuel temperatures to be associated.ECU 30 receives the output signal from various sensors (coolant temperature sensor 31 and the fuel pressure sensor 23 that comprise the coolant temperature that is used to detect internal-combustion engine).Coolant temperature sensor 31 and ECU 30 constitute device for monitoring temperature.
Based on from signal of sensor, ECU 30 comes controlling combustion engine according to various programs.For fuel injection apparatus, ECU 30 control electromagnetic relief valve 19 and the opening of electromagnetic valve 25 and fuel injection timings of manifold injection device 9 and in-cylinder injection device 13 or the like.
First embodiment's fuel injection apparatus is configured to monitor near the temperature of spray-hole of in-cylinder injection device 13, and when near the temperature the spray-hole that obtains by monitoring is higher than reference temperature, increases by high-pressure fuel supply system 4 circuit fuel quantities.For example, only carrying out that fuel sprays by manifold injection device 9 and high-pressure fuel supply system 4 in fuel do not move or the circuit state under, carry out the circulation of fuel.The concrete control procedure that is used to realize this fuel cycle is described referring now to Fig. 2.
When beginning during by the control of 30 pairs of fuel injection apparatus of ECU, in step (following summary be " S ") 1, whether judgement is 100% tuned port injection state.Here, 100% tuned port injection state refers to only carry out the state that fuel sprays by manifold injection device 9.
Determine the fuel spray regime according to engine loading (for example, the depression degree of accelerator pedal).For example, be lower than in the low loaded work piece of first reference value, only carry out fuel and spray by in-cylinder injection device 13 in depression degree.Be higher than in the high capacity work of second reference value in depression degree, only carry out fuel and spray by manifold injection device 9.Both be not less than first reference value in depression degree and also be not higher than in the middle loaded work piece of second reference value, both carry out fuel with for example 20%: 80% requirement ratio and spray to utilize in-cylinder injection device 13 and manifold injection device 9.Therefore, can judge whether be 100% tuned port injection state according to engine loading (for example, the depression degree of accelerator pedal).
If at S1 is "Yes", then handles and proceed to S2.At S2, judge whether the fuel temperature in the direct injection delivery pipe has been increased to critical fuel temperature.Here, the fuel temperature in the direct injection delivery pipe is meant the temperature of fuel in the in-cylinder injection delivery pipe 12.Critical fuel temperature is corresponding to reference temperature.
Although it is optimal directly detecting near the temperature of spray-hole of in-cylinder injection device 13, in the present embodiment, what obtain is the temperature that is supplied to the fuel under high pressure of in-cylinder injection device 13, i.e. the temperature of in-cylinder injection delivery pipe 12 inner high voltage fuel.In addition, by with reference to be stored among the ROM of ECU 30, expression sprays as a side coolant temperature and fuel and continues and as the figure of the relation between the opposing party's the fuel temperature, according to the coolant temperature that detects by coolant temperature sensor 31 with only use manifold injection device 9 to carry out the endurance of fuel injection, obtain the fuel temperature in the direct injection delivery pipe, replace directly detecting the temperature of in-cylinder injection delivery pipe 12 inner high voltage fuel.Then, judge whether the fuel temperature that is obtained has arrived critical fuel temperature.
If at S2 is "Yes", then handles and proceed to S3.At S3, activate and open electromagnetic valve 25.Under 100% tuned port injection state, electromagnetic relief valve 19 is always opened.Therefore, low-pressure fuel flows into pumping chamber 16 in suction stroke.But, even because electromagnetic relief valve 19 also is in open mode in delivery stroke, so only make fuel supercharging slightly in the pumping chamber 16.At this moment, under the situation that electromagnetic valve 25 is closed, the fuel in the high-pressure fuel supply system 4 does not move.Therefore, the fuel in the pumping chamber 16 is provided to low-pressure fuel 3, and perhaps, the safety check 28 of release channel 27 is opened fuel is released into fuel tank 5.
Therefore, by opening electromagnetic valve 25, the fuel in the in-cylinder injection delivery pipe 12 can be released into fuel tank 5, and by open on the high pressure fuel passage 11 safety check 22 with in the pumping chamber 16 slightly the supply of fuel of supercharging to in-cylinder injection delivery pipe 12.In this way, make fuel cycle by high-pressure fuel supply system 4.
At S4, determine to activate the endurance (or actuation duration of valve) of electromagnetic valve 25 according to the coolant temperature that is detected by coolant temperature sensor 31.Particularly, higher coolant temperature means higher engine temperature, therefore sets the actuation duration of valve longer.On the contrary, lower coolant temperature means lower engine temperature, therefore sets the actuation duration of valve shorter.
At S5, judge whether the actuation duration of valve passes through.If process is then handled and proceeded to S6, it closes electromagnetic valve 25 to stop the circulation of fuel.
If the above-mentioned "No" that is judged to be in S2 is then handled and is back to S1.That is,, then do not carry out fuel cycle by high-pressure fuel supply system 4 if under 100% tuned port injection state, be not increased to critical fuel temperature even judge the fuel temperature in the in-cylinder injection delivery pipe 12 yet.
In above-mentioned fuel injection apparatus, when only using manifold injection device 9 carrying out the fuel injection, be increased to critical fuel temperature if judge the fuel temperature in the in-cylinder injection delivery pipe 12, then begun the fuel cycle of being undertaken by high-pressure fuel supply system 4.Fuel when mobile, can cool off the parts of high-pressure fuel supply system 4 in high-pressure fuel supply system 4.Therefore, the circulation of fuel has been guaranteed to have circulated by high-pressure fuel supply system 4 and has been had than near the fuel of low temperature more of the temperature spray-hole.Therefore, can cool off as the in-cylinder injection device 13 of the parts of high-pressure fuel supply system 4, can accurately control the fuel quantity in the firing chamber 2 that is ejected into internal-combustion engine thus to suppress near the expansion the spray-hole.
In above-mentioned fuel injection apparatus, monitor near the spray-hole temperature according to the fuel temperatures in the high-pressure fuel supply system 4.Because fuel is filled in the in-cylinder injection device 13, thus fuel temperature almost with spray-hole near temperature equate.Therefore, by the fuel temperature in the monitoring high-pressure fuel supply system 4, can highly precisely monitor near the temperature of spray-hole.
In addition, near the above-mentioned fuel injection apparatus of the temperature monitor spray-hole according to the fuel temperature in the high-pressure fuel supply system 4, the situation compared near the temperature direct measurement and the monitoring spray-hole can prevent the complicated of structure.That is, directly measuring and monitor under near the situation of the temperature spray-hole, because temperature detection sensor need be mounted to the less relatively in-cylinder injection device of size, so structure will be comparatively complicated.Present embodiment has been avoided the structure of this complexity.
In above-mentioned fuel injection apparatus, because according to the coolant temperature of the internal-combustion engine that is detected by coolant temperature sensor 31 with only use manifold injection device 9 to carry out the endurance that fuel sprays and estimate, so can accurately estimate fuel temperature in the high-pressure fuel supply system 4.That is, the coolant temperature of internal-combustion engine is corresponding to engine temperature, and expection coolant temperature (engine temperature) is high more, and the fuel temperature in the high-pressure fuel supply system 4 is also high more.In addition, the long endurance of only using manifold injection device 9 to carry out the fuel injection means the supply of fuel that stops to in-cylinder injection device 13, thereby the temperature of expection in-cylinder injection device can raise owing to the stagnation fuel of high temperature.Therefore, can accurately estimate fuel temperature according to coolant temperature and duration of charge.
In addition, coolant temperature (can use coolant temperature sensor 31 to detect) can be common to the control to internal-combustion engine.The endurance (can obtain by algorithm operating or according to pre-prepd figure) of using manifold injection device 9 to carry out the fuel injection also can be used for the control to internal-combustion engine.Therefore, can under the situation that does not need extra structure, obtain coolant temperature and carry out the endurance that fuel sprays, can easily realize present embodiment thus by manifold injection device 9.
In above-mentioned fuel injection apparatus, only make fuel cycle in the demand period of determining according to the fuel temperature in the high-pressure fuel supply system 4.Therefore, compared to only making the situation of the fuel cycle in the in-cylinder injection fuel system by spray whole period during driving internal-combustion engine from manifold injection device 9 independent fuel, the driving that has reduced to cause because of cycling is lost, and can cool off in-cylinder injection device 13 effectively.In addition, can prevent owing in the fuel efficiency deterioration that the increase of friction causes, make that the load of internal-combustion engine is lower.
In above-mentioned fuel injection apparatus, when only carrying out the fuel injection separately, be elevated to the level of critical fuel temperature if judge the fuel temperatures in the high-pressure fuel supply system 4 by manifold injection device 9, then make fuel cycle.Therefore, compared to making the situation of the fuel cycle in the in-cylinder injection fuel system only spraying whole period during driving internal-combustion engine by fuel from manifold injection device 9, the driving that has reduced to cause because of cycling is lost, and can cool off in-cylinder injection device 13 effectively.
Simultaneously, in existing equipment, when only carrying out fuel when spraying from the manifold injection device, under the situation that fuel in the in-cylinder injection device does not move, because do not obtain the cooling effect that brings by fuel, so fuel and in-cylinder injection device all obtain high temperature, this will cause the expansion of in-cylinder injection device parts.For example, when carrying out the feedback control of fuel injection amount, after the fuel injection that and then switches to by the in-cylinder injection device, because the expansion of sparger, fuel injection amount becomes immediately less than its desired value, causes rare combustion regime thus.Therefore, in existing equipment, desired value is set at higher value sprays to carry out fuel.Subsequently, along with the continuation that the fuel that carries out from the in-cylinder injection device sprays, sparger is cooled off by institute's supplied fuel, thus the expansion that has alleviated parts.Fuel injection amount becomes greater than desired value thus, thereby causes the combustion regime of overrich.Therefore, in existing equipment, desired value becomes lower value and sprays to carry out fuel.As mentioned above, in existing fuel injection apparatus, fuel injection amount changes in the time of can switching to by the fuel injection of in-cylinder injection device in the fuel injection of manifold injector in by cylinder, and this will influence combustion regime and exhaust emissions unfriendly.
On the contrary, according to above-mentioned fuel injection apparatus, can be near the expansion only carrying out suppressing when fuel sprays the spray-hole of in-cylinder injection device 13 via manifold injection device 9, therefore when spraying, the fuel that switches to by in-cylinder injection device 13 can accurately control fuel injection amount spraying from fuel by manifold injection device 9.
In above-mentioned fuel injection apparatus, for the circulation of fuel, the low-pressure fuel of supplying from fuel tank 5 is supplied to high-pressure fuel supply system 4 under not by the situation of high pressure fuel pump 10 superchargings.Therefore, can carry out fuel cycle and not apply higher load to internal-combustion engine.
As mentioned above, the fuel injection apparatus according to first embodiment can provide following effect.
(1) in the present embodiment, when only using manifold injection device 9 carrying out the fuel injection, be increased to critical fuel temperature, then begun fuel cycle by high-pressure fuel supply system 4 if judge the fuel temperatures in the in-cylinder injection delivery pipe 12.Therefore, can cool off as the in-cylinder injection device 13 of the parts of high-pressure fuel supply system 4, can accurately control the fuel quantity in the firing chamber 2 that is ejected into internal-combustion engine thus to suppress near the expansion the spray-hole.Therefore, can keep good combustion regime and favourable exhaust emissions.
(2) in the present embodiment, monitor near the spray-hole temperature according to the fuel temperatures in the high-pressure fuel supply system 4.Therefore, can highly precisely monitor near the temperature of spray-hole.
(3) in the present embodiment, monitor near the spray-hole temperature according to the fuel temperatures in the high-pressure fuel supply system 4.Therefore, compared near the situation of temperature direct measurement and the monitoring spray-hole, avoided complicated structure.
(4) in the present embodiment, because according to the coolant temperature of the internal-combustion engine that is detected by coolant temperature sensor 31 with only use manifold injection device 9 to carry out the endurance that fuel sprays and estimate, so can accurately estimate fuel temperature in the high-pressure fuel supply system 4.In addition, can therefore can easily realize present embodiment need not under the situation of additional configurations to obtain coolant temperature and carrying out endurance of burner oil by manifold injection device 9.
(5) in the present embodiment, only make fuel cycle according to the determined demand of the fuel temperature period in the high-pressure fuel supply system 4.Therefore, compared to only making the situation of fuel cycle by the in-cylinder injection fuel system by spray whole period during driving internal-combustion engine from manifold injection device 9 independent fuel, reduce the driving loss that causes because of cycling, and can cool off in-cylinder injection device 13 effectively.In addition, can prevent owing in the fuel efficiency deterioration that the increase of friction causes, make that the load of internal-combustion engine is lower.
(6) in the present embodiment, when only carrying out the fuel injection, be increased to the level of critical fuel temperature, then carried out fuel cycle if judge the fuel temperatures in the high-pressure fuel supply system 4 by manifold injection device 9.Therefore, compared to making the situation of fuel cycle by the in-cylinder injection fuel system only spraying whole period during driving internal-combustion engine by fuel from manifold injection device 9, reduce the driving loss that causes because of cycling, and can cool off in-cylinder injection device 13 effectively.In addition, when only carrying out the fuel injection, can suppress near the expansion of spray-hole of in-cylinder injection device 13 by manifold injection device 9.Therefore, when spraying the fuel that switches to by in-cylinder injection device 13 from the fuel by manifold injection device 9 and spray, can accurately control fuel injection amount.
(7) in the present embodiment, for fuel cycle, the low-pressure fuel of supplying from fuel tank 5 is supplied to high-pressure fuel supply system 4 under not by the situation of high pressure fuel pump 10 superchargings.Therefore, can carry out fuel cycle and not apply higher load to internal-combustion engine.
Note, can following modification first embodiment.
---when fuel temperature raise, fuel pressure also raise, and can open electromagnetic valve 25 in the case and reduce fuel pressure to discharge fuel to fuel tank 5.Therefore, can be arranged so that after the beginning fuel cycle, when the fuel pressure (fuel pressure in-cylinder injection delivery pipe 12 in) that is detected by fuel pressure sensor 23 becomes when carrying out critical fuel pressure (it guarantees to carry out the fuel injection from in-cylinder injection device 13 with minimum injection limit) that fuel sprays with minimum injection limit, stop fuel cycle.By such control,, can carry out fuel with minimum injection limit and spray when switching to fuel by in-cylinder injection device 13 when spraying.
---in above embodiment, the low-pressure fuel of supplying from fuel tank 5 is not circulating under the situation by high pressure fuel pump 10 superchargings.Alternatively, can carry out supercharging by 10 pairs of low-pressure fuels of high pressure fuel pump, and the fuel under high pressure of acquisition is circulated.When making the fuel under high pressure circulation time, can after and then spraying the fuel injection that switches to by in-cylinder injection device 13, carry out fuel immediately and spray from fuel by manifold injection device 9.In addition,,, more substantial fuel is circulated, quicken cooling thus in-cylinder injection device 13 compared to low-pressure fuel is carried out the circuit situation when fuel under high pressure is carried out circulation time.In addition, when fuel under high pressure is carried out circulation time, even also can circulate when the small amount of fuel of in-cylinder injection device 13 is sprayed when carrying out to fuel.This has suppressed near the expansion of the parts spray-hole of the in-cylinder injection device 13 that causes because of small injection fuel and the deficiency to the cooling of in-cylinder injection device 13 that therefore causes, thereby this has guaranteed that suitable fuel sprays.
---when circulating fuel under high pressure as mentioned above, although can carry out fuel immediately after spraying the fuel injection that switches to by in-cylinder injection device 13 from the fuel by manifold injection device 9 sprays, if but fuel pressure is too high, then will spray a large amount of fuel, cause being difficult to realizing that carrying out fuel from in-cylinder injection device 13 with minimum injection limit sprays.Be conceived to this, can be arranged in circulates to fuel under high pressure reaches after the specified time period, stop high pressure fuel pump 10 to carry out the circulation of low-pressure fuel, subsequently, reach when being used for carrying out critical fuel pressure that fuel sprays in the fuel pressure that is detected by fuel pressure sensor 23, close electromagnetic valve 25 to stop fuel cycle with minimum injection limit.By such control, can when spraying, fuel by in-cylinder injection device 13 guarantee that carrying out fuel with minimum injection limit sprays switching to.
---in the above-described embodiments, under the 100% tuned port injection state that only carries out the fuel injection, make fuel cycle from manifold injection device 9.Alternatively, can be arranged to not only under state only, also under the state that sprays the relatively small amount fuel from in-cylinder injection device 13, to carry out fuel cycle by manifold injection device 9 burner oils.This realizes 80% and realize the situation that 20% fuel sprays from in-cylinder injection device 13 corresponding to for example carrying out from manifold injection device 9, but need the fuel under high pressure that circulates as mentioned above in the case, this is because also carried out the fuel injection by in-cylinder injection device 13.
---in the above-described embodiments, by reference drawing, according to coolant temperature with only carry out endurance that fuel sprays and obtain fuel temperature in the in-cylinder injection delivery pipe 12 by manifold injection device 9.Alternatively, can utilize temperature transducer directly to measure fuel temperature.
---in the above-described embodiments, monitor near the temperature the spray-hole of in-cylinder injection device 13 according to the fuel temperatures in the in-cylinder injection delivery pipe 12.Alternatively, can directly measure near the temperature of spray-hole by the serviceability temperature sensor.
(second embodiment)
To the second embodiment of the present invention be described with reference to figure 3 and Fig. 4.Structure according to second embodiment's the fuel injection apparatus that is used for internal-combustion engine is identical with structure shown in Figure 1, therefore will no longer repeat the description to it.Control procedure in the fuel injection apparatus is described now.Fig. 3 is the flow chart that the control procedure among second embodiment is shown, and Fig. 4 is the sequential chart that the state of a control among second embodiment is shown.
Fuel pressure in second embodiment's the fuel injection apparatus monitoring in-cylinder injection device 13, when the fuel pressure that is obtained by monitoring was not less than reference pressure P1, it outwards discharged the in-cylinder injection delivery pipe 12 interior fuel that in-cylinder injection device 13 is installed to it.To concrete control procedure and the state of a control that be used to discharge fuel be described with reference to figure 3 and Fig. 4.In the structure of Fig. 1, low-pressure fuel pump 6, high pressure fuel pump 10, release channel 24 and electromagnetic valve 25 are corresponding to releasing device.
When beginning to control, judge whether be 100% tuned port injection state at S11 by 30 pairs of fuel injection apparatus of ECU.Carry out this judgement in the mode identical with S1 among above-mentioned Fig. 2.
If at S11 is "Yes", then handles and proceed to S12.At S12, judge whether the fuel pressure in the direct injection delivery pipe is equal to or higher than reference pressure P1.Here, the fuel pressure in the direct injection delivery pipe is the fuel pressure in the in-cylinder injection delivery pipe 12.Although the fuel pressure that directly detects in the in-cylinder injection device 13 is optimal, but the fuel pressure that detects in the direct injection delivery pipe also is feasible, this is because fuel is supplied to in-cylinder injection device 13 from in-cylinder injection delivery pipe 12, and the fuel pressure in the direct injection delivery pipe equals the fuel pressure in the in-cylinder injection device 13 thus.Detect fuel pressure in the direct injection delivery pipe by fuel pressure sensor 23 (it is corresponding to pressure monitoring device).Then, judge whether the fuel pressure that is detected is equal to or higher than reference pressure P1.
If at S12 is "Yes", then process proceeds to S13.At S13, activate and open electromagnetic valve 25.Then, at S14, activate high pressure fuel pump 10.That is, as shown in Figure 4, judging that fuel pressure is equal to or higher than the time point t1 of reference pressure P1, opens electromagnetic valve 25 and activates high pressure fuel pump 10.
Therefore, by opening electromagnetic valve 25, the fuel in the in-cylinder injection delivery pipe 12 can be released into fuel tank 5, and from high pressure fuel pump 10 supply fuel under high pressure, make it possible to carry out fuel cycle by high-pressure fuel supply system 4.By above-mentioned fuel cycle, although be difficult to change the fuel pressure (referring to the figure of the fuel pressure among Fig. 4) in fuel pressure in the direct injection delivery pipe and the in-cylinder injection device 13 because supplying fuel under high pressure, can reduce the interior fuel temperature (referring to the figure of the fuel temperature among Fig. 4) of fuel temperature in the direct injection delivery pipe and in-cylinder injection device 13.
At S15, judge whether activate beginning from high pressure fuel pump 10 has passed through specified time period W1.This specified time period W1 is stored among the ROM in the ECU 30 in advance, and activates high pressure fuel pump 10 during this period.Promptly, because known in advance time per unit flow rate at high pressure fuel pump 10 actuating time institute's circuit fuel, so (this relation shows the duration of corresponding fuel cycle to the relation between the endurance that can obtain fuel cycle in advance and the drop-out value of fuel temperature, and utilize this relation the degree that fuel temperature reduced), to determine specified time period W1.If passed through specified time period W1, then handle proceeding to S16 in the S15 judgement.
At S16, stop high pressure fuel pump 10.Stop high pressure fuel pump 10 and mean that the electromagnetic relief valve 19 with high pressure fuel pump 10 is set at normally open.Under this state, although the fuel as mentioned above in the pumping chamber 16 of high pressure fuel pump 10 is only by supercharging slightly, because opened electromagnetic valve 25, so can be to the fuel in the fuel tank 5 release in-cylinder injection delivery pipes 12.So, in pumping chamber 16 by the supply of fuel of supercharging slightly to in-cylinder injection delivery pipe 12, thus by high-pressure fuel supply system 4 circulation low-pressure fuels.This has reduced the fuel pressure in the direct injection delivery pipe.By the circulation of fuel, also can reduce the fuel temperature in the direct injection delivery pipe.
More specifically, as shown in Figure 4, during the specified time period W1 from time point t1 to time point t2 (activating high pressure fuel pump 10 and open electromagnetic valve 25 during this period), although fuel pressure reduces hardly, fuel temperature is reduced to temperature T 2 from temperature T 1.Subsequently, during the period that high pressure fuel pump 10 stops and electromagnetic valve 25 is opened therein, fuel pressure reduces and fuel temperature also reduces.During the specified time period W1 of the fuel under high pressure that wherein circulates the rate of descent of fuel temperature greater than the period (from t2 to t3) of the low-pressure fuel that wherein circulates during the rate of descent of fuel temperature.This is because in the flow rate of fuel under the situation of the circulation fuel under high pressure flow rate greater than fuel under the situation of circulation low-pressure fuel.
At S17, judge whether the fuel pressure in the direct injection delivery pipe has become the critical fuel pressure Pmin that is used for carrying out with minimum injection limit the fuel injection.Here, being used for carrying out the critical fuel pressure Pmin that fuel sprays with minimum injection limit is meant and can may carries out the fuel pressure that fuel sprays from in-cylinder injection device 13 with minimum injection limit.When the fuel pressure in the direct injection delivery pipe becomes the critical fuel pressure Pmin that is used for carrying out with minimum injection limit that fuel sprays, handle proceeding to S18.At S18, close electromagnetic valve 25 to stop the circulation of fuel.That is, as shown in Figure 4, the fuel pressure in the direct injection delivery pipe has become the time point t3 that is used for carrying out with minimum injection limit the critical fuel pressure Pmin of fuel injection, closes electromagnetic valve 25.During the period that high pressure fuel pump 10 stops and electromagnetic valve 25 is opened therein (from t2 to t3), fuel pressure is reduced to from reference pressure P1 and is used for carrying out the critical fuel pressure Pmin that fuel sprays with minimum injection limit, and fuel temperature is reduced to temperature T 3 from temperature T 2.
If in the "No" that is judged to be of S12, then handle and be back to S11.That is,,, then do not carry out the release fuel cycle of high-pressure fuel supply system 4 (that is, by) to fuel in the in-cylinder injection delivery pipe 12 if the fuel pressures in the in-cylinder injection delivery pipe 12 are lower than reference pressure P1 even under 100% tuned port injection state.
In the present embodiment, when the fuel pressure in the in-cylinder injection device 13 becomes when being equal to or greater than reference pressure P1, the fuel that in-cylinder injection device 13 are installed in its in-cylinder injection delivery pipe 12 are released into fuel tank 5.Such fuel discharges can reduce the fuel pressure that is supplied to in-cylinder injection device 13.When critical fuel pressure Pmin that fuel pressure becomes that the minimum injection limit that is used for in-cylinder injection device 13 carries out that fuel sprays, stop the release of fuel.Therefore, by guaranteeing to be used for carrying out the critical fuel pressure Pmin of fuel injection, can realize easily that the fuel that carries out with minimum injection limit sprays with minimum injection limit.
In addition, in the present embodiment, when the fuel pressure in the in-cylinder injection device 13 becomes when being equal to or higher than reference pressure P1, the in-cylinder injection delivery pipe 12 interior fuel that in-cylinder injection device 13 are installed to it are released into fuel tank 5, in addition, during specified time period W1, fuel under high pressure is supplied to in-cylinder injection delivery pipe 12 from high pressure fuel pump 10.This causes the circulation of fuel under high pressure, suppresses to be supplied to the rising of temperature of the fuel of in-cylinder injection device 13 thus, and simultaneously, fuel itself can cool off in-cylinder injection device 13, especially near the part the spray-hole.As a result, suppressed near the expansion of spray-hole of in-cylinder injection device 13, can accurately control the fuel quantity in the firing chamber that is ejected into internal-combustion engine thus, thereby guarantee good combustion regime and favourable exhaust emissions.Specified time period W1 through after, circulating to become until fuel pressure from the low-pressure fuel of low-pressure fuel pump 6 is used for carrying out the critical fuel pressure Pmin that fuel sprays with minimum injection limit.In this way, compared to making low-pressure fuel circuit situation,, can quicken cooling to in-cylinder injection device 13 by at first making the fuel under high pressure circulation.
As mentioned above, according to second embodiment's fuel injection apparatus, can realize following effect.
(1) in the present embodiment, when the fuel pressure in the in-cylinder injection device 13 becomes when being equal to or higher than reference pressure P1, the fuel in the in-cylinder injection delivery pipe 12 are released into fuel tank 5 become until fuel pressure and be used for in-cylinder injection device 13 and carry out the critical fuel pressure Pmin that fuel sprays with minimum injection limit.By guaranteeing to be used for carrying out the critical fuel pressure Pmin of fuel injection, can realize easily that carrying out fuel with minimum injection limit from in-cylinder injection device 13 sprays thus with minimum injection limit.
(2) in the present embodiment, the fuel in the in-cylinder injection delivery pipe 12 is released into fuel tank 5, at first fuel under high pressure is circulated in addition.Compared to making low-pressure fuel circuit situation, can quicken cooling thus to in-cylinder injection device 13.As a result, near the expansion of spray-hole of in-cylinder injection device 13 can be suppressed, the fuel quantity in the firing chamber that is ejected into internal-combustion engine can be accurately controlled thus.Therefore, can keep good combustion regime and favourable exhaust emissions.
Note, can following modification second embodiment:
---can be arranged to become when being equal to or higher than reference pressure P1 when the fuel pressure in the in-cylinder injection device 13, the fuel that in-cylinder injection device 13 is installed in its in-cylinder injection delivery pipe 12 is released into fuel tank 5, and under the situation that does not activate high pressure fuel pump 10 low-pressure fuel is supplied to in-cylinder injection delivery pipe 12 from low-pressure fuel pump 6.In the case, make the low-pressure fuel circulation, make it possible to apace the fuel pressure in the in-cylinder injection device 13 is reduced to be used for carrying out the critical fuel pressure Pmin that fuel sprays with minimum injection limit.
(the 3rd embodiment)
Now the third embodiment of the present invention will be described.Fig. 5 shows by the fuel system 90 as the motor of controlling according to the Engine ECU of the control gear of present embodiment.This motor is the eight-in V petrol engine, and has and be used for the manifold injection device 120 that injects fuel into the in-cylinder injection device 110 of each cylinder and be used for injecting fuel into the intake manifold of each cylinder.Notice that the present invention also not exclusively is applied to above-mentioned motor, but also can be applicable to the petrol engine and the co-rail diesel motor of other types.In addition, the quantity of high pressure fuel pump is not limited to one, and can be two or more.
As shown in Figure 5, this fuel system 90 comprises and is arranged in the fuel tank and is used for supply pump 100 with low pressure discharge pressure (with the corresponding about 400kPa of the pressure of pressure regulator) fuel supplying, high pressure fuel pump 200 by cam 210 drivings, for each setting in the cylinder block of the left and right sides and be used for the high-pressure delivery pipe 112 of high-pressure fuel supply to in-cylinder injection device 110, be used for each of left and right sides cylinder block and be arranged on four in-cylinder injection devices 110 at corresponding high-pressure delivery pipe 112 places, for each setting in the cylinder block of the left and right sides and be used to supply fuel to the static pressure line 122 of manifold injection device 120, and be used for each of left and right sides cylinder block and be arranged on four manifold injection devices 120 at corresponding static pressure line 122 places.
The discharge port of the supply pump 100 in fuel tank is connected to low pressure feed pipe 400, and it branches into the first low-pressure delivery connecting tube 410 and pump supply tube 420.The first low-pressure delivery connecting tube 410 is branched off into the static pressure line 122 of a cylinder block in the V-type cylinder group, and in this point of branching downstream, it forms the static pressure line 122 that the second low-pressure delivery connecting tube, 430, the second low-pressure delivery connecting tubes 430 are connected to another cylinder block.
The discharge port of high pressure fuel pump 200 is connected to high-pressure delivery connecting tube 500, and high-pressure delivery connecting tube 500 is connected to the high-pressure delivery pipe 112 of a cylinder block in the V-type cylinder group.The high-pressure delivery pipe 112 of a cylinder block is connected with the high-pressure delivery pipe 112 of another cylinder block via high pressure connecting tube 520.
The safety valve 114 that is arranged on high-pressure delivery pipe 112 places is connected to high-pressure delivery recurrent canal 610, and high-pressure delivery recurrent canal 610 is connected to high pressure fuel pump recurrent canal 600.The port that returns of high pressure fuel pump 200 is connected to high pressure fuel pump recurrent canal 600.High pressure fuel pump recurrent canal 600 is connected to recurrent canal 620, and recurrent canal 620 then is connected to fuel tank.
Fig. 6 is Fig. 5 mesohigh petrolift 200 and zoomed-in view on every side thereof.High pressure fuel pump 200 has to be driven by cam 210 and is used as critical piece with pump plunger 206, electromagnetic relief valve 202 that slides up and down and the safety check 204 that is provided with the leakage function.
When moving down pump plunger 206 and when electromagnetic relief valve 202 is opened, introduce (suction) fuel by cam 210.When moving up pump plunger 206 by cam 210, change is closed the opportunity of electromagnetic relief valve 202 with the fuel quantity of control from high pressure fuel pump 200 dischargings.During the supercharging stroke that pump plunger 206 moves up, along with the opportunity of closing electromagnetic relief valve 202, more then the fuel quantity of discharging was big more, the fuel quantity of late more then discharging is more little along with the opportunity of closing electromagnetic relief valve 202.The driving dutycycle of electromagnetic relief valve 202 is set to 100% when the fuel of discharging maximum flow, and the driving dutycycle of electromagnetic relief valve 202 is set to 0% when the fuel of discharging minimum flow.When the driving dutycycle is 0%, electromagnetic relief valve 202 stays open, in the case, although slide up and down along with cam 210 continues to rotate (along with the revolution of motor) pump plunger 206, but do not close because of electromagnetic relief valve 202, so not to fuel pressure boost.
The pushing of the fuel that is pressurized is also opened have the leakage function safety check 204 of (its setting pressure is about 60kPa), and fuel is supplied to high-pressure delivery pipe 112 via high-pressure delivery connecting tube 500.At this moment, control fuel pressure by the fuel pressure sensor that is arranged on high-pressure delivery pipe 112 places with feedback system.As mentioned above, the high-pressure delivery pipe 112 at each cylinder block place connects via high pressure connecting tube 520.
Safety check 204 with leakage function is common type but is provided with the safety check in the hole of often opening.When the fuel pressure in the high pressure fuel pump 200 (pump plunger 206) (for example becomes when being lower than fuel pressure in the high-pressure delivery connecting tube 500, when electromagnetic relief valve 202 stays open when motor stops that cam 210 stops thus), fuel under high pressure in the high-pressure delivery connecting tube 500 is back to high pressure fuel pump 200 1 sides by described hole, has reduced in the high-pressure delivery connecting tube 500 thus and the fuel pressure in the high-pressure delivery pipe 112.Therefore, for example when motor stopped, the fuel in the high-pressure delivery pipe 112 was not in high pressure, so avoided fuel to spill from in-cylinder injection device 110.
Fig. 7 shows the figure of explanation from the relation between the temperature of the fuel quantity (controlled by the driving dutycycle of pump) of high pressure fuel pump 200 discharging and in-cylinder injection device 110 tail ends.As shown in Figure 7, along with the fuel quantity from the high pressure fuel pump discharging increases, because greater amount fuel has absorbed in-cylinder injection device 110 more heat, so can cool off in-cylinder injection device 110 to a greater degree.This has reduced the temperature of in-cylinder injection device 110 tail ends.Safety temperature shown in Figure 7 is the upper limit that can not produce sedimental temperature in the spray-hole of in-cylinder injection device 110 tail ends.Notice that the temperature (for example, the temperature of engine coolant) that can utilize motor is represented from the relation between the temperature of the fuel quantity of high pressure fuel pump 200 dischargings and in-cylinder injection device 110 tail ends as parameter.That is, can set a plurality of figure as shown in Figure 7 for different engineer coolant temperatures.It shall yet further be noted that figure shown in Figure 7 only is example, the present invention is not limited to this.
Fig. 8 utilizes engine speed and the engine loading isothermal chart as the temperature of in-cylinder injection device 110 tail ends of parameter.Usually, the temperature of in-cylinder injection device 110 tail ends is higher than having in the zone of hanging down engine speed in having the zone of higher engine speed, and higher than having in the zone of hanging down engine loading in having than the zone of high engine loads.But it should be noted, as shown in Figure 8, engine speed and engine loading be by-level but not in the zone of highest level temperature the highest.In addition, also there is such zone, that is, even temperature is also higher for low load but under specific engine speed.Each motor all has unique isothermal chart.In addition, except engine speed and engine loading, the isothermal chart of the temperature of in-cylinder injection device 110 tail ends can also utilize engine temperature (for example, engineer coolant temperature) as another parameter.That is, can prepare a plurality of figure as shown in Figure 8 for different engineer coolant temperatures.Isothermal chart shown in Figure 8 is an example only, and the present invention is not limited to this.
With reference to the control structure of Fig. 9 description by the performed program of the Engine ECU of the control gear of realizing present embodiment.
At S100, Engine ECU detection of engine coolant temperature.At S110, Engine ECU detection of engine speed and engine loading.At S120, Engine ECU utilization isothermal chart is as shown in Figure 8 estimated the temperature T of in-cylinder injection device 110 tail ends.At this moment, can be according to arbitrarily both combinations or estimate the temperature T of in-cylinder injection device 110 tail ends according to whole threes' combination in engineer coolant temperature, engine speed and the engine loading.
At S130, Engine ECU judges whether the temperature T of in-cylinder injection device 110 tail ends is higher than safety temperature (safety temperature for example shown in Figure 7).If the temperature T of in-cylinder injection device 110 tail ends is higher than safety temperature (being "Yes" among the S130), then handles and proceed to S140.Otherwise (being "No" in S130) then handled and proceeded to S150.
At S140, Engine ECU is calculated and the corresponding driving dutycycle of fuel quantity (it can be reduced to safety temperature with the temperature of in-cylinder injection device 110 tail ends) of discharging from high pressure fuel pump 200.Use figure as shown in Figure 7 this moment.
At S150, Engine ECU is calculated and the corresponding driving dutycycle of fuel quantity from high pressure fuel pump 200 dischargings according to engine speed, engine loading and (between in-cylinder injection device 110 and the manifold injection device 120) fuel injection ratio.
At S160, the Engine ECU utilization is recently controlled from the fuel quantity of high pressure fuel pump 200 dischargings at the driving duty of S140 or S150 calculating.
To describe now according to the work of said structure and flow chart by the high-pressure fuel system of the Engine ECU control of the control gear of realizing present embodiment.In the following description, the fuel spray regime of in-cylinder injection device 110 can be the state that the fuel quantity that spraying reduces, and perhaps can be the state that stops from its burner oil.
When engine operation, the temperature of detection of engine freezing mixture (S100), and detection of engine speed and engine loading (S110).Estimate the temperature T (S120) of in-cylinder injection device 110 tail ends as the figure of parameter according to utilize engineer coolant temperature, engine speed and engine loading shown in Figure 8.
When the temperature T of in-cylinder injection device 110 tail ends was higher than safety temperature (is "Yes" at S130), the driving dutycycle of calculating high pressure fuel pump 200 makes can be guaranteed the temperature of in-cylinder injection device 110 tail ends is reduced to safety temperature (S140) from the fuel quantity of its discharging.Utilize the driving duty recently to control the opportunity (S160) of closing electromagnetic relief valve 202.Because along with more then can discharge more substantial fuel the opportunity of closing electromagnetic relief valve 202, so when increasing discharge amount, can increase the driving dutycycle.Therefore, the more substantial fuel of high pressure fuel pump 200 dischargings.
Be supplied to high-pressure delivery pipe 112 from the fuel of high pressure fuel pump 200 dischargings via high-pressure delivery connecting tube 500, and the in-cylinder injection device 110 of cooling respective bank.Subsequently, fuel is dispensed to the high-pressure delivery pipe 112 of another cylinder block by high pressure connecting tube 520, cools off the in-cylinder injection device 110 of associated cylinder group thus.Fuel then is back to fuel tank via the safety valve 114 that is arranged on place, high-pressure delivery pipe 112 ends and by high-pressure delivery recurrent canal 610 and recurrent canal 620.
As mentioned above, according to the control gear of present embodiment, the fuel quantity that discharges from high pressure fuel pump is controlled as the safety temperature that makes the temperature of in-cylinder injection device tail end not be higher than the generation of inhibition sediments.For example, even be under zero the situation, also the fuel quantity from the high pressure fuel pump discharging can be defined as having the thermal capacity that the estimation temperature of guaranteeing in-cylinder injection device tail end reduces reducing the fuel injection amount that carries out from the in-cylinder injection device or being set.Therefore, by fuel cooling in-cylinder injection device, and the temperature of reduction in-cylinder injection device tail end is to suppress sedimental formation.
(modified example)
Control gear according to modified example of the present invention below will be described.Control gear according to this modified example is carried out the program different with the program of the foregoing description.Other hardware configurations (Fig. 5 and Fig. 6) are general, therefore will no longer repeat its detailed description.
This modified example relates to the control that is restricted under the situation that the fuel injection amount that carries out from in-cylinder injection device 110 is zero (being that in-cylinder injection device 110 stops) high pressure fuel pump 200.Even be under zero the situation at the fuel injection amount that carries out from in-cylinder injection device 110, also high pressure fuel pump 200 controlled and made it discharge whole fuel quantity.Do like this, the fuel of the maximum emission of high pressure fuel pump 200 is circulated by high-pressure fuel system, and can cool off in-cylinder injection device 110 with a large amount of fuel, can farthest avoid sedimental generation in the spray-hole of in-cylinder injection device 110 tail ends in the case.
Alternatively, be under zero the situation, can also control the fuel quantity that the temperature that makes its discharging make in-cylinder injection device tail end is no more than safety temperature at the fuel injection amount that carries out from in-cylinder injection device 110 to high pressure fuel pump 200.Do like this, the fuel quantity less than the maximum emission of high pressure fuel pump is circulated by high-pressure fuel system.Therefore, in reducing high pressure fuel pump, can cool off in-cylinder injection device 110 by fuel in the loss (frictional loss), can avoid sedimental generation in the spray-hole of in-cylinder injection device 110 tail ends thus.
(motor that this control gear was suitable for (1))
The motor (1) that control gear of the present invention is suitable for will be described now.
Referring now to Figure 10 and Figure 11, the figure that each all shows fuel injection ratio (it is regarded as the information relevant with the working state of motor) between in-cylinder injection device 110 and the manifold injection device 120 is described.Here, the fuel injection ratio between two spargers also is expressed as the ratio that the fuel quantity that sprays from in-cylinder injection device 110 accounts for total fuel quantity of injection, and it is called as " fuel injection ratio of in-cylinder injection device 110 ", or " DI (direct injection) is than (r) ".Figure is stored among the ROM of Engine ECU.Figure 10 is the figure that is used for engine warm state, and Figure 11 is the figure that is used for engine cold state.
In Figure 10 and figure shown in Figure 11, transverse axis is represented the engine speed of motor, and the longitudinal axis is represented load factor, and the fuel injection ratio of in-cylinder injection device 110 (or DI ratio r) is expressed as percentage.
As shown in Figure 10 and Figure 11, set the DI ratio r for each working zone of determining by the engine speed and the load factor of motor." DI ratio r=100% " expression only uses in-cylinder injection device 110 to carry out the zone that fuel sprays, and " DI ratio r=0% " expression only uses manifold injection device 120 to carry out the zone that fuel sprays.Each all represents " DI ratio r ≠ 0% ", " DI ratio r ≠ 100% " and " 0%＜DI ratio r＜100% " to use in-cylinder injection device 110 and manifold injection device 120 both carries out the zone that fuel sprays.In general, in-cylinder injection device 110 helps to improve output performance, and manifold injection device 120 helps the uniformity of sky burning mixt.These two kinds of spargers according to the engine speed and the load factor of motor suitably select to have different qualities only evenly burn under the common working state (but not the non-common working state the catalyst warm-up state during idling) of motor thus.
In addition, as shown in Figure 10 and Figure 11, defined fuel injection ratio (or DI ratio r) between in-cylinder injection device 110 and the manifold injection device 120 respectively at the figure that is used for engine warm state and the figure that is being used for engine cold state.These figure are configured to show the temperature change along with motor, the different control areas of in-cylinder injection device 110 and manifold injection device 120.When the temperature of detected motor is equal to or higher than predetermined temperature threshold, just selects the figure that is used for warm attitude as shown in figure 10, otherwise just select the figure that is used for cold conditions as shown in figure 11.Come the one or both in the sparger 110 and manifold injection device 120 in the control cylinder according to the engine speed of motor and load factor and based on selected figure.
To be described in the engine speed and the load factor of the motor of setting among Figure 10 and Figure 11 now.In Figure 10, NE (1) is set to 2500rpm to 2700rpm, and KL (1) is set to 30% to 50%, and KL (2) is set to 60% to 90%.In Figure 11, NE (3) is set to 2900rpm to 3100rpm.That is NE (1)＜NE (3).KL (3) and KL (4) among NE among Figure 10 (2) and Figure 11 are also suitably set.
When contrast Figure 10 and Figure 11, the NE (3) of the figure that is used for cold conditions shown in Figure 11 is higher than the NE (1) of the figure that is used for warm attitude shown in Figure 10.This shows that along with the reduction of engine temperature, the control area of manifold injection device 120 expands to and comprises the more zone of high engine speed.That is, under the colder situation of motor, sediments unlikely is accumulated in the spray-hole of in-cylinder injection device 110 (even not from in-cylinder injection device 110 burner oils).Therefore, thus use manifold injection device 120 to carry out the zone that fuel sprays and can expand to improve uniformity.
When contrast Figure 10 and Figure 11, " DI ratio r=100% " is arranged in wherein at the figure that is used for warm attitude that the engine speed of motor is NE (1) or higher zone, and engine speed is NE (3) or higher zone and be arranged in wherein at the figure that is used for cold conditions.For load factor, " DI ratio r=100% " is arranged in wherein at the figure that is used for warm attitude that load factor is KL (2) or bigger zone, and load factor is KL (4) or bigger zone and be arranged in wherein at the figure that is used for cold conditions.This means and only in the zone of predetermined high engine speed and in the zone of predetermined high engine loads, use in-cylinder injection device 110.Promptly, in high-speed region or high load area, to spray even only use in-cylinder injection device 110 to carry out fuel, the engine speed of motor and load are also higher, guaranteed sufficient air inflow, even only use in-cylinder injection device 110 also can easily obtain uniform empty burning mixt thus.In this way, the fuel that sprays from in-cylinder injection device 110 atomizes in the firing chamber, and it relates to the latent heat of vaporization (perhaps, absorbing heat from the firing chamber).Therefore, the temperature of empty burning mixt reduces at the compressed ends place, thereby has improved anti-knock performance.In addition, because combustion chamber temperature reduces,, produce higher power output thus so improved intake efficiency.
At the figure that is used for warm attitude of Figure 10, also when load factor be KL (1) or more hour, only use in-cylinder injection device 110 to carry out fuel and spray.This shows when the temperature of motor 10 is higher in predetermined low load area and only uses in-cylinder injection device 110 separately.When motor was in warm attitude, sediments was likely to accumulate in the spray-hole of in-cylinder injection device 110.But, when using in-cylinder injection device 110 to carry out the fuel injection, can reduce the temperature of spray-hole, prevent sedimental accumulating thus.In addition, in the minimum fuel injection amount of determining in-cylinder injection device 110, can prevent its obstruction.Therefore, in the relevant range, only use in-cylinder injection device 110.
When contrast Figure 10 and Figure 11, there is the zone of " DI ratio r=0% " in the figure that only is used for cold conditions in Figure 11.This shows when the temperature of motor is hanged down at predetermined low load area (KL
(3) or littler) in only use manifold injection device 120 to carry out fuel to spray.Colder when motor, load is lower and air inflow hour, not too be easy to generate fuel atomizing.In this zone, be difficult to utilize the fuel of in-cylinder injection device 110 to spray and guarantee favourable burning.In addition, particularly in low load low-speed region, do not need to use the height output of in-cylinder injection device 110.Therefore, in the relevant range, only use manifold injection device 120 but not in-cylinder injection device 110 carries out fuel sprays.
In addition, in other work except common work, perhaps under the catalyst warm-up state during motor 10 idling (non-common working state), sparger 110 is to carry out stratified-charge combustion in the control cylinder.By carrying out stratified-charge combustion, can promote the preheating of catalyzer, and improve exhaust emissions thus at the catalyst warm-up duration of work.
(motor that this control gear was suitable for (2))
The motor that control gear was suitable for (2) of present embodiment below will be described.In following description, will no longer repeat and the similar structure of motor (1) motor (2).
With reference to Figure 12 and Figure 13, will the figure that each all shows the fuel injection ratio (it is regarded as the information relevant with the working state of motor 10) between in-cylinder injection device 110 and the manifold injection device 120 be described.Figure is stored among the ROM of Engine ECU.Figure 12 is the figure that is used for the warm attitude of motor, and Figure 13 is the figure that is used for the cold conditions of motor.
Figure 12 and Figure 13 are different from Figure 10 and Figure 11 in the following areas.At the figure that is used for warm attitude, in being equal to or higher than the zone of NE (1), the engine speed of motor keeps " DI ratio r=100% ", and be used for the figure of cold conditions, in being equal to or higher than the zone of NE (3), the engine speed of motor keeps " DI ratio r=100% ".In addition, do not comprise low-speed region, is to keep " DI ratio r=100% " in KL (2) or the bigger zone at the figure that is used for warm attitude at load factor, and is to keep " DI ratio r=100% " in KL (4) or the bigger zone at the figure that is used for cold conditions at load factor.This means that only using in-cylinder injection device 110 to carry out fuel sprays in engine speed is in the zone of predetermined high level, and in engine loading is in the zone of predetermined high level, often only uses in-cylinder injection device 110 to carry out fuel and spray.But in the low speed high load area, the Combination of the empty burning mixt that the fuel that is sprayed by in-cylinder injection device 110 forms is relatively poor, and this uneven empty burning mixt can cause rough burning in the firing chamber.Therefore, along with engine speed raises (the problems referred to above unlikely take place), the fuel injection ratio of in-cylinder injection device 110 increases, and along with engine loading reduces (the problems referred to above take place easily), the fuel injection ratio of in-cylinder injection device 110 reduces.By the cross arrow among Figure 12 and Figure 13 the fuel injection ratio of in-cylinder injection device 110 or the variation of DI ratio r are shown.In this way, can suppress the fluctuation of the engine output torque that causes because of rough burning.Note, these means almost are equal to the means that reduce the fuel injection ratio of in-cylinder injection device 110 when the state of motor when predetermined low-speed region moves, and perhaps increase the means of the fuel injection ratio of in-cylinder injection device 110 when predetermined low load area moves when the state of motor.In addition, except relevant range (representing) by the cross arrow among Figure 12 and Figure 13, only using in-cylinder injection device 110 to carry out in the zone that fuel sprays (on the high-speed side and on low load side), even when only using in-cylinder injection device 110 to carry out the fuel injection, also can easily obtain uniform empty burning mixt.In the case, the fuel that sprays from in-cylinder injection device 110 atomizes in the firing chamber, and it relates to the latent heat of vaporization (perhaps, absorbing heat from the firing chamber).Therefore, can reduce, improve anti-knock performance thus in the temperature of compressed side air-fuel mixture.In addition, the temperature reduction along with the firing chamber has improved intake efficiency, produces higher power output thus.
In the motor of describing with reference to figures 10 to Figure 13, be set in by fuel injection timing and realize even burning in the aspirating stroke, and in compression stroke, realize stratified-charge combustion by being set with in-cylinder injection device 110.That is, when the fuel injection timing of in-cylinder injection device 110 is set in the compression stroke, dense empty burning mixt can be arranged around spark plug partial ground, be made that the rarer empty burning mixt of integral body is lighted with the realization stratified-charge combustion in the firing chamber.Even the fuel injection timing of in-cylinder injection device 110 is set in the aspirating stroke,, still can realize stratified-charge combustion if can provide dense empty burning mixt around spark plug partly.
As used herein, stratified-charge combustion comprises stratified-charge combustion and semi-stratified charge combustion.In semi-stratified charge combustion, manifold injection device 120 produces rare and uniform empty burning mixt at the aspirating stroke burner oil with inner in whole firing chamber, then, in-cylinder injection device 110 to produce the dense empty burning mixt around spark plug, improves combustion regime at compression stroke injection fuel thus.Because following reason, this semi-stratified charge combustion are preferred in catalyst warm-up work.In catalyst warm-up work, need considerably retarded spark timing and keep the combustion regime (idling mode) that needs, make high-temperature combustion gas arrive catalyzer thus.In addition, the fuel that needs the supply specified quantitative.If adopt stratified-charge combustion to satisfy above-mentioned requirements, the amount of fuel is with deficiency.If adopt evenly burning, the retardation of burning that is used to keep needs is less compared to the situation of stratified-charge combustion.For this reason, although in catalyst warm-up work, both can adopt stratified-charge combustion also can adopt semi-stratified charge combustion, preferably adopt above-mentioned semi-stratified charge combustion.
In addition, in the motor of describing in conjunction with Figure 10 to Figure 13, with corresponding fundamental region, whole zone almost in, the fuel injection timing of in-cylinder injection device 110 is set in the aspirating stroke (here, the fundamental region refers to that except by carrying out from manifold injection device 120 in aspirating stroke that fuel sprays and carry out fuel from in-cylinder injection device 110 in compression stroke and spray zone the zone of the semi-stratified charge combustion that realizes, semi-stratified charge combustion is only carried out in catalyst warm-up state).But because following reason, for smooth combustion, the fuel injection timing of in-cylinder injection device 110 can temporarily be set in the compression stroke.
When the fuel injection timing of in-cylinder injection device 110 is set in the compression stroke, when the temperature of cylinder is higher relatively, cool off empty burning mixt by the fuel that sprays.This has improved cooling effect, and has improved knock resistance thus.In addition, when the fuel injection timing of in-cylinder injection device 110 was set in the compression stroke, the time that is ejected into igniting from fuel was shorter, and this has guaranteed the permeability that burner oil is stronger, has improved rate of combustion thus.Can prevent combustion fluctuation to the raising of knock resistance and to the raising of rate of combustion, improve combustion stability thus.
It will be appreciated that the embodiment of Jie Shiing is in all fields and illustrates, and nonrestrictive here.Scope of the present invention by the clause of claim but not above description define, and scope of the present invention is intended to comprise scope that the clause that falls into claim is equal to mutually and any modification in the implication.
Claims (4)
1, a kind of fuel facility that is used for internal-combustion engine, described internal-combustion engine have second fuel injection system that is used for injecting fuel into first fuel injection system of cylinder and is used for injecting fuel into intake manifold, and described fuel facility comprises:
Pressure monitoring device, it is used for monitoring the fuel pressure of described first fuel injection system;
Releasing device, it is used for the fuel that described first fuel injection system is installed in its delivery pipe is outwards discharged; With
Control gear, it is used for activating described releasing device to discharge the fuel in the described delivery pipe when being not less than reference pressure by the described fuel pressure that described pressure monitoring device obtained, reduce described fuel pressure thus, and be used for becoming and stop described releasing device when being used to make described first fuel injection system to carry out critical pressure that fuel sprays with minimum injection limit in described fuel pressure.
2, the fuel facility that is used for internal-combustion engine according to claim 1, wherein,
Described releasing device comprises the low-pressure fuel pump that is used for from the fuel tank fuel supplying, be used for from the further supercharging of the fuel of described low-pressure fuel pump and with high-pressure fuel supply to the high pressure fuel pump of described delivery pipe, be used for discharging the release channel of fuel and being arranged on the safety valve of described release channel to described fuel tank from described delivery pipe, and
Described control gear comprises such device, it is used for opening described safety valve to discharge the fuel in the described delivery pipe when being not less than reference pressure by the described fuel pressure that described pressure monitoring device obtained, and activate described high pressure fuel pump reach specified time period with high-pressure fuel supply to described delivery pipe, and scheduled time slot through after low-pressure fuel is supplied to described delivery pipe from described low-pressure fuel pump, and be used for when reaching the described critical pressure that is used for carrying out fuel injection by the described fuel pressure that described pressure monitoring device obtained, closing described safety valve to stop the release of fuel with minimum injection limit.
3, the fuel facility that is used for internal-combustion engine according to claim 1, wherein,
Described releasing device comprises the low-pressure fuel pump that is used for from the fuel tank fuel supplying, be used for from the further supercharging of the fuel of described low-pressure fuel pump and with high-pressure fuel supply to the high pressure fuel pump of described delivery pipe, be used for discharging the release channel of fuel and being arranged on the safety valve of described release channel to described fuel tank from described delivery pipe, and
Described control gear comprises such device, it is used for opening described safety valve discharging the fuel in the described delivery pipe and low-pressure fuel is supplied to described delivery pipe from described low-pressure fuel pump when being not less than reference pressure by the described fuel pressure that described pressure monitoring device obtained, and is used for closing described safety valve to stop the release of fuel when being used for carrying out described critical pressure that fuel sprays with minimum injection limit being become by the described fuel pressure that described pressure monitoring device obtained.
4, according to each described fuel facility that is used for internal-combustion engine in the claim 1 to 3, wherein,
Described first fuel injection system is the in-cylinder injection device, and
Described second fuel injection system is the manifold injection device.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004295220 | 2004-10-07 | ||
| JP2004295220 | 2004-10-07 | ||
| JP2004360046 | 2004-12-13 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200580034454 Division CN101040111A (en) | 2004-10-07 | 2005-09-06 | Fuel supply apparatus for internal combustion engine |
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| CN101451474A true CN101451474A (en) | 2009-06-10 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNA2008101903062A Pending CN101451475A (en) | 2004-10-07 | 2005-09-06 | Fuel supply apparatus for internal combustion engine |
| CN 200580034454 Pending CN101040111A (en) | 2004-10-07 | 2005-09-06 | Fuel supply apparatus for internal combustion engine |
| CNA2008101903058A Pending CN101451474A (en) | 2004-10-07 | 2005-09-06 | Fuel supply apparatus for internal combustion engine |
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| CNA2008101903062A Pending CN101451475A (en) | 2004-10-07 | 2005-09-06 | Fuel supply apparatus for internal combustion engine |
| CN 200580034454 Pending CN101040111A (en) | 2004-10-07 | 2005-09-06 | Fuel supply apparatus for internal combustion engine |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105089770A (en) * | 2014-05-06 | 2015-11-25 | 福特环球技术公司 | Method and system for direct injection noise mitigation |
| CN106285986A (en) * | 2015-06-24 | 2017-01-04 | 罗伯特·博世有限公司 | For the method running internal combustion engine |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009134854A2 (en) * | 2008-05-02 | 2009-11-05 | Gm Global Technology Operations, Inc. | Extension of the application of multiple injection hcci combustion strategy from idle to medium load |
| CN101825496B (en) * | 2010-05-04 | 2012-09-05 | 奇瑞汽车股份有限公司 | Device for calculating temperature substitute value of engine temperature sensor |
| US9074550B2 (en) * | 2010-10-27 | 2015-07-07 | Toyota Jidosha Kabushiki Kaisha | Fuel injection control system for internal combustion engine |
| JP5500102B2 (en) * | 2011-02-24 | 2014-05-21 | マツダ株式会社 | Control device for spark ignition gasoline engine |
| DE112011105170T5 (en) * | 2011-04-20 | 2014-02-20 | Toyota Jidosha Kabushiki Kaisha | Fuel supply device for internal combustion engine |
| EP2861852B1 (en) | 2012-06-14 | 2018-04-04 | Westport Power Inc. | Fuel system protection in a multi-fuel system internal combustion engine |
| JP5998751B2 (en) * | 2012-08-29 | 2016-09-28 | マツダ株式会社 | Spark ignition direct injection engine |
| CA2809298C (en) | 2013-03-12 | 2014-05-13 | Westport Power Inc. | Fuel injector temperature mitigation |
| US9453474B2 (en) * | 2013-06-12 | 2016-09-27 | Ford Global Technologies, Llc | Method for operating a direct fuel injection system |
| DE102014224468A1 (en) * | 2014-11-28 | 2016-06-16 | Robert Bosch Gmbh | Method for controlling a fuel pump, an internal combustion engine |
| US9657680B2 (en) * | 2014-12-30 | 2017-05-23 | Ford Global Technologies, Llc | Zero flow lubrication for a high pressure fuel pump |
| JP7020338B2 (en) * | 2018-08-07 | 2022-02-16 | トヨタ自動車株式会社 | Internal combustion engine control device |
-
2005
- 2005-09-06 CN CNA2008101903062A patent/CN101451475A/en active Pending
- 2005-09-06 CN CN 200580034454 patent/CN101040111A/en active Pending
- 2005-09-06 CN CNA2008101903058A patent/CN101451474A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105089770A (en) * | 2014-05-06 | 2015-11-25 | 福特环球技术公司 | Method and system for direct injection noise mitigation |
| CN106285986A (en) * | 2015-06-24 | 2017-01-04 | 罗伯特·博世有限公司 | For the method running internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101451475A (en) | 2009-06-10 |
| CN101040111A (en) | 2007-09-19 |
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