Abstract: A knocking determining apparatus of an internal combustion engine that includes an in-cylinder injector and an intake port injector and that determines knocking based on an output signal of a knock sensor. The knocking determining apparatus includes a knocking determination prohibition unit prohibiting, when a ratio of fuel injection from the in-cylinder injector and the intake port injector is changed, knocking determination for a prescribed period after that change, or a knocking determination level change unit changing a knocking determination level for a prescribed period after that change.

Abstract: A method of operating an internal combustion engine including at least a combustion chamber having a piston disposed therein, wherein the combustion chamber is configured to receive air, a first fuel and a second fuel to form a substantially homogeneous mixture, and wherein the piston is configured to compress said mixture so that auto-ignition of said mixture is achieved is disclosed. The method comprises varying the amount of at least one of the first fuel and the second fuel that is received by the combustion chamber to adjust the timing of auto-ignition, where the first fuel includes diesel fuel and the second fuel includes such low cetane fuels as: methanol and ethanol.

Abstract: A double system of fuel injection type internal combustion engine includes: a direct injection injector and a port fuel injection injector; a control unit for changing a fuel injection distribution ratio of fuels injected from these injectors; a delivery pipe for the direct injection injector; a high pressure fuel pump; a fuel pressure sensor and a fuel temperature sensor for detecting a fuel pressure and a fuel temperature in the delivery pipe; and a fuel regulating unit for regulating the fuel pressure and fuel temperature in the delivery pipe. The control unit can control the fuel regulating unit so as to lower the exceeding value thereof when the fuel injection distribution ratio of the port fuel injection injector is higher than that of the direct injection injector and at least one of the fuel pressure value and fuel temperature value exceeds an aimed value.

Abstract: A method to control injection timing for an internal combustion engine having a plurality of injectors in at least a cylinder, the method comprising of injecting a first fuel amount to at least a cylinder of an internal combustion engine from a first injector, injecting a second fuel amount fuel to said cylinder from a second injector, and adjusting the timing between starting or ending injection of said first fuel amount, and starting or ending of said second fuel amount in response to an operating condition of said engine.

Abstract: An Engine ECU executes a program including the steps of: calculating (S100) a wall deposit correction quantity fmw, a DI reference injection quantity taudb of an in-cylinder injector, and a PFI reference injection quantity taupb of an intake manifold injector; sensing (S200) an engine coolant temperature THW; if THW is higher than a THW threshold value (YES in S300) and DI ratio r is not 100% (NO in S400), making a correction (S600) with wall deposit correction quantity fmw using the intake manifold injector; if THW is at most THW threshold value (NO in S300), making a correction (S500) with wall deposit correction quantity fmw using the in-cylinder injector.

Abstract: At the time of startup of an engine having an in-cylinder injector and an intake manifold injector, a risk of pre-ignition during the first-time compression stroke is determined based on a rotational angle of a crankshaft at the time of previous engine stop. When there is a high risk of pre-ignition, fuel injection from the in-cylinder injector having been set to make an air-fuel ratio within the combustion chamber become out of a range enabling combustion (to attain an over-rich condition) is carried out in addition to fuel injection from the intake manifold injector for normal engine startup. Pre-ignition is thus prevented, and smooth engine startup is ensured.

Abstract: An in-cylinder injector injects fuel to be sprayed in the form of an inverted letter V sandwiching a spark plug, as seen in a top view, and in a sector as seen in a side view. The sprayed fuel interferes with an intake valve assuming an open position. An engine ECU executes a program including the steps of: determining with reference to a map a timing of injection of the fuel through the in-cylinder injector (S100); determining a period for injection from an amount of fuel injected (S110); determining in accordance with map whether the sprayed fuel interferes with the intake valve (S120); modifying the period for injection to be advanced by a period for injection having the sprayed fuel interfering with the intake valve (S130); and determining a timing of injection and a period for injection (S140).

Abstract: When an injection sharing ratio r is neither 0 nor 1, an engine ECU executes a program including a step of calculating a purge reduction amount of an in-cylinder injector as fpg×r and calculating a purge reduction amount of an intake manifold injector as fpg×(1?r) when performing purge processing according to a current fuel injection sharing ratio of the injectors, and a step of calculating a correction fuel injection amount of the in-cylinder injector by raising the fuel injection amount to a minimum fuel injection amount, and calculating a correction fuel injection amount of the intake manifold injector by subtracting the raised amount from the fuel injection amount of the intake manifold injector when the fuel injection amount of the in-cylinder injector calculated by using the purge reduction amount is lower than the minimum injection amount.

Abstract: In an internal combustion engine where an in-cylinder injector and an intake manifold injector can both be used, initial setting of a fuel injection ratio (DI ratio) in accordance with a condition of the engine is basically carried out in response to power-up of an engine ECU. Further, it is sensed that an engine start request is made after a prescribed period has elapsed since the power-up. In such a case, an initial setting value of the fuel injection ratio is updated in accordance with the condition of the engine at that time point. Thus, the fuel injection ratio between both injectors can appropriately be set in starting the engine, so that the engine is smoothly started.

Abstract: The present invention provides an internal combustion engine which can produce several types of fuels from a single fuel as needed. The internal combustion engine comprises reforming means 3 for reforming a first fuel to be used in homogeneous charge compression ignition combustion into a second fuel having high ignitability, by making the first fuel contact with a catalyst formed from N-hydroxyphthalimide. The engine uses the second fuel when conducting diesel combustion. The engine can switch between the homogeneous charge compression ignition combustion with the use of the first fuel and the diesel combustion with the use of the second fuel. The engine conducts the homogeneous charge compression ignition combustion when a load is low, and conducts the diesel combustion when the load is high.

Abstract: An internal combustion engine includes an in-cylinder injection valve and an intake passage injection valve. A control apparatus of the engine determines whether the temperature of a component located in the exhaust passage is higher than or equal to a predetermined temperature. When the temperature of the component is higher than or equal to the predetermined temperature, the control apparatus increases, without changing the total amount of fuel supplied to the cylinder, the ratio of a fuel injection amount of the intake passage injection valve to a fuel injection amount of the in-cylinder injection valve compared to a case where the temperature of the component is not higher than or equal to the predetermined temperature. Therefore, the catalyst is reliably prevented from being overheated, while preventing the fuel economy from deteriorating.

Abstract: At least one engine operating parameter other than total fuel energy content is taken into account when transitioning between operating modes in a dual fuel or other multimode engine (20) in order to maintain a smooth transition between modes. The parameter preferably comprises at least one of primary fuel excess air ratio (lambda) and ignition timing and preferably is controlled in addition to total fuel energy content control. Lambda control is especially beneficial because it permits the control system to compensate for the engine's inability to substantially alter the instantaneous air mass in the combustion chamber during the transition period. For instance, during a transition from pilot ignited gaseous fuel mode to diesel mode, the controlled parameter preferably comprises diesel lambda, and the controlling step comprises setting diesel lambda at a relatively high value at the beginning of the transition period and thereafter reducing diesel lambda during the transition period.

Abstract: For an internal combustion engine having an in-cylinder injector and an intake manifold injector, setting of the ratio of fuel injection (DI ratio) between these injectors is changed depending on whether the intake manifold injector is in a high temperature state or a non-high temperature state (normal state). Specifically, when the intake manifold injector is at a high temperature, the setting of the DI ratio is controlled so that the quantity of fuel to be injected from the intake manifold injector is larger than that according to setting of the fuel injection quantity in the normal state under the same engine conditions.

Abstract: The engine ECU executes a program including the step of detecting an engine coolant temperature, the step of detecting an engine speed and an engine load, the step 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, the step 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 of controlling the high-pressure fuel pump using the drive duty.

Abstract: A low-pressure delivery pipe provided with intake manifold injectors, a fuel pressure regulator, a high-pressure fuel pump, a high-pressure delivery pipe provided with in-cylinder injectors, and an electromagnetic relief valve are connected in series at the downstream of a low-pressure fuel pump that discharges a fuel within a fuel tank at a prescribed pressure. Since the low-pressure delivery pipe is arranged downstream of the low-pressure fuel pump, the fuel pressure within the low-pressure delivery pipe is lowered upon stop of vehicle operation, in response to stop of the low-pressure fuel pump. The fuel pressure within the high-pressure delivery pipe is also lowered in response to stop of the low-pressure fuel pump, by opening the electromagnetic relief valve upon stop of vehicle operation. Thus, oil tightness of the injectors during the stop of vehicle operation is ensured.

Abstract: An engine ECU executes a program including the steps of: when the port fuel injection ratio is 100% (YES at S200), sensing the engine coolant temperature THW (S210); when the engine coolant temperature THW is higher than a threshold value (YES at S220), monitoring fuel pressure P in a high-pressure delivery pipe (S230); and when fuel pressure P rises by the received heat (YES at S240), identifying that there is no error at the high-pressure fuel system.

Abstract: An engine ECU executes a program including the steps of: detecting an air-fuel ratio; calculating a learn value of a feedback correction amount for total fuel injection amount calculated based on the air-fuel ratio, for a plurality of learning regions obtained as a result of division corresponding to an intake air amount; interpolating the learn value at an intake air amount different from the intake air amount detected at the time of calculation of the learn value, based on the calculated learn value; and correcting an amount of fuel injection based on the obtained learn value.

Abstract: An internal combustion engine includes an in-cylinder injection valve and an intake passage injection valve. A control apparatus of the engine determines whether a catalyst located in an exhaust passage is in an overtemperature condition. When the catalyst is determined to be in the overtemperature condition, the control apparatus controls the injection valves to increase the amount fuel supplied to the cylinder compared to a case where the catalyst is determined not to be in the overtemperature condition. The control apparatus sets a mode for causing the injection valves to increase the amount of supplied fuel according to an operational state of the engine. For example, in a case where the component is determined to be in the overtemperature condition when the engine is operating in a fuel injection mode in which fuel is injected at least from the in-cylinder injection valve, at least the intake passage injection valve performs fuel injection for increasing the supplied fuel.

Abstract: A homogeneous charge compression ignition internal combustion engine capable of reliably reducing flame noise at a time of high-load operation is provided. The engine includes an injector 12a which injects a liquid hydrocarbon fuel to an intake port 23, and an injector 12b which directly injects an alcohol fuel into a combustion chamber 21. The liquid hydrocarbon fuel is distributed to an outer peripheral side of the combustion chamber 21, and the alcohol fuel is distributed to a central portion. The engine includes intake valves 25a and 25b, and divides an intake stroke into a period in which the intake valve 25a is stopped and a fuel-gas mixture is flown, and a period in which the intake valves 25a and 25b are operated and the flow is suppressed, guides the liquid hydrocarbon fuel into the combustion chamber 21 during the flow period, and injects the alcohol fuel to the combustion chamber 21 during the flow suppression period.

Abstract: When an injection sharing ratio r is neither 0 nor 1, an engine ECU executes a program including a step of calculating a purge reduction amount of an in-cylinder injector as fpg×r and calculating a purge reduction amount of an intake manifold injector as fpg×(1-r) when performing purge processing according to a current fuel injection sharing ratio of the injectors, and a step of calculating a correction fuel injection amount of the in-cylinder injector by raising the fuel injection amount to a minimum fuel injection amount, and calculating a correction fuel injection amount of the intake manifold injector by subtracting the raised amount from the fuel injection amount of the intake manifold injector when the fuel injection amount of the in-cylinder injector calculated by using the purge reduction amount is lower than the minimum injection amount.

Abstract: An engine ECU executes a program including the steps of calculating an in-cylinder injector's injection ratio; if the ratio is 1, calculating an amount of cold state spark advance by employing a function f(1) having the engine's temperature as a parameter; if the ratio is 0, calculating an amount of cold state spark advance by employing a function f(2) having the engine's temperature as a parameter; and if the ratio is larger than 0 and smaller than 1, calculating an amount of cold state spark advance by employing a function f(3) having the engine's temperature and the ratio as parameters.

Abstract: An internal combustion engine includes an engine control unit for setting a ratio of fuel injection quantity of both the injectors. The engine control unit includes a memory storing four sheets of ignition timing maps, with reference to which the maximum torque generation timing and knocking limit torque generation timing, at the direct injection injector (100%) and port fuel injection injector (100%), are calculated. The engine control unit further operates to calculate a correction amount from correction amount map, and calculates first interpolation value of the maximum torque generation timing at the above 100% operation time of both the injectors and second interpolation value of the knocking limit torque generation timing at the above 100% operation time of both the injectors. A value in which the correction amount is added to either one of the above first and second interpolation value on a delay angle side is calculated as ignition timing.

Abstract: An engine ECU executes a program including the steps of: detecting a fuel pressure in a high-pressure fuel system (S130) if a lock-up clutch is not in a released state (NO at S100) and if a tip end temperature of an in-cylinder injector is equal to or lower than a temperature threshold value (NO at S120); calculating fuel pressure lowering ?P as a result of fuel injection from the in-cylinder injector (S140); calculating fuel shortage amount ?Q corresponding to fuel pressure lowering shortage (S170) if ?P is smaller than a fuel pressure threshold (YES at S150); and injecting fuel from an intake manifold injector in an amount obtained by adding ?Q to an amount of fuel injection from the intake manifold injector of a cylinder (S180).

Abstract: An internal combustion engine includes a port injector injecting a fuel into an intake port, an in-cylinder injector directly injecting a fuel into a combustion chamber, and an ECU. When the ECU determines that an operation state of the internal combustion engine exhibits a transition state, the ECU obtains an estimated load factor of the internal combustion engine based on the operation state of the internal combustion engine, and calculates a fuel injection ratio between the port injector and the in-cylinder injector based on the estimated load factor.

Abstract: An engine ECU executes a program including the steps of calculating an in-cylinder injector's injection ratio; if the ratio is 1, calculating a cold state increase value by employing a function f(1) having the engine's temperature as a parameter; if the ratio is 0, calculating a cold state increase value by employing a function f(2) having the engine's temperature as a parameter; and if the ratio is larger than 0 and smaller than 1, calculating a cold state increase value by employing a function f(3) having the engine's temperature and the ratio as parameters.

Abstract: An engine ECU executes a program including the steps of: selecting a map for a warm state or a map for a cold state based on an engine coolant temperature after an engine is started and rapid catalyst warm-up ends; calculating DI ratio r; calculating when to inject fuel from an intake manifold injector as time in synchronization with air intake if a load factor is equal to or greater than a threshold value and fuel is injected from injectors at a ratio predetermined therebetween; and otherwise calculating when to inject fuel from the intake manifold injector as during a period in which an intake valve is closed.

Abstract: An engine ECU executes a program including the steps of: determining presence of abnormality in a high-pressure fuel system; when abnormality is sensed in the high-pressure fuel system, and not in an in-cylinder injector, injecting fuel from the in-cylinder injector at the feed pressure; selecting criteria (1) that is the restriction standard for a more gentle output restriction of the engine; when abnormality is sensed in the high-pressure fuel system and in the in-cylinder injector, ceasing the in-cylinder injector; selecting criteria (2) that is the restriction standard for a stricter output restriction of the engine; increasing the VVT overlap; retarding the ignition timing; and restricting the throttle opening according to the selected criteria.

Abstract: The technique of the present invention produces a first fuel-air mixture containing a first fuel and the air at a specific ratio, which does not allow for auto ignition of the first fuel-air mixture by simple compression, in a combustion chamber. The technique then injects a second fuel, which has a higher octane value than that of the first fuel, into a partial area of the combustion chamber, so as to produce a second fuel-air mixture. The technique ignites the second fuel-air mixture for combustion, so as to compress and auto-ignite the first fuel-air mixture. The second fuel has the higher octane value, so that a combustion start timing of the second fuel-air mixture is reliably regulated by ignition. Namely the technique positively controls the timing of auto ignition of the first fuel-air mixture. Setting an adequate value to the ignition timing thus effectively prevents the occurrence of knocking.

Abstract: An engine ECU executes a program including the step of closing a current control valve in all regions when there is abnormality in a high-pressure system fuel system (YES at S100), the step of setting the VVT overlap to 0, the step of injecting fuel from only an intake manifold injector, the step of corresponding to an ignition timing when the current control valve is closed, and the step of correcting the increased quantity of fuel.

Abstract: It is determined whether an internal combustion engine is in an idle state or in a non-idle state based on the throttle opening degree. DI ratio control for controlling fuel injection ratio between in-cylinder injection and port injection is performed in accordance with different control modes in the idle state and in the non-idle state. While the DI ratio control mode is basically switched according to transition between the idle and non-idle states, in the engine cold state where fuel deposition disturbing air-fuel ratio control is likely to occur, a transition delay period is provided upon transition from the non-idle state to the idle state. During the transition delay period, the control mode is fixed irrespective of the transition between the idle and non-idle states. This prevents intermittent changes of the DI ratio, and thus, prevents variation in engine output.

Abstract: A low-pressure fuel supply system for applying pressure to a fuel by using a feed pump and supplying the fuel to a manifold fuel injection mechanism, and a high-pressure fuel supply system branched from the low-pressure fuel supply system and for applying pressure to the low-pressure fuel by using a high-pressure pump of a metering delivery type driven in accordance with the engine operation state and supplying the resultant fuel to an in-cylinder fuel injection mechanism are provided. The high-pressure pump supplies all the pressurized fuel to the high-pressure fuel supply system, irrespective of an actuation state of the in-cylinder fuel injection mechanism. Excessive fuel is returned when a relief valve is opened. Thus, pulsation caused by operation of the high-pressure pump is reduced, and the fuel can be supplied in a proper quantity.

Abstract: An engine system and method are disclosed for controlling pre-ignition of an alcohol fuel. In one embodiment, the fuel injection timing is adjusted to cause the fuel to avoid combustion chamber surfaces. In another embodiment, the fuel injection timing is adjusted to spray the fuel directly onto the piston surface to cool the piston. Also disclosed is a cylinder cleaning cycle in which engine knock is purposely caused for one to hundreds of engine cycles by adjusting the fuel content away from alcohol toward gasoline. Further measures to cause knock which are disclosed: adjusting spark timing, intake boost, exhaust gas fraction in the cylinder, cam timing, and transmission gear ratio.

Abstract: A reference injection quantity of fuel to be injected from a port injection valve and an in-cylinder injection valve as well as an injection ratio are determined based on an operation condition. A ratio between a feedback correction amount for port injection and a feedback correction amount for in-cylinder injection is set equal to a ratio of the reference injection quantity. If an injection quantity obtained as a result of addition of a correction amount is smaller than a minimum injection quantity of the injection valve, feedback correction is prohibited. Meanwhile, if the feedback correction amount is small, only the injection valve attaining a larger injection quantity is subjected to feedback correction.

Abstract: A system for an engine of a vehicle, comprising of a cylinder of the engine, a first injector configured to inject a first fuel to said cylinder, a second injector configured to inject a second fuel to said cylinder, and a controller configured to, during a first operating condition, commence combustion in the engine by injecting fuel into said cylinder from only said first injector during a first start, and during a second operating condition, to commence combustion in the engine by injecting fuel into said cylinder from only said second injector during a second start.

Abstract: An engine ECU executes a program including the step of detecting an engine coolant temperature (THW), the step of selecting a map for a warm state as the map for calculating a fuel injection ratio (or a DI ratio) (r) when the engine coolant temperature (THW) is equal to or higher than a temperature threshold value (THW(TH)), the step of selecting a map for a cold state as the map for calculating the fuel injection ratio (or the DI ratio) (r) when the engine coolant temperature (THW) is lower than the temperature threshold value (THW(TH)), and the step of calculating the fuel injection ratio between the in-cylinder injector and the-intake manifold injector (or the DI ratio) (r) based on the engine speed, load factor, and the selected map.

Abstract: An engine ECU executes a program including the step of calculating an injection time Astart from the engine speed and load factor when arriving at the injection calculation timing of a cylinder located in the proximity of a knock sensor, the step of calculating an injection period TAU, the step of calculating an injection end time Aend, the step of shortening the injection time of an in-cylinder injector when the injection time Astart or injection end time Aend is within a KCS gate, and the step of calculating the port injection period so as to inject the insufficient injection quantity from an intake manifold injector when the required injection quantity will be insufficient as a result of shortening the injection period of the in-cylinder injector.

Abstract: In a hybrid vehicle driven by a dual injection internal combustion engine including an injector for in-cylinder injection and an injector for in-intake air path injection, and assistive dynamic, to control learning of the internal combustion engine's air fuel ratio learning value to learn the engine's air fuel ratio the engine is steadily operated and only any one of the injectors is allowed to inject fuel, while learning of the air fuel ratio is controlled, and after controlling the learning has completed the other injector is alone allowed to inject the fuel, while learning of air fuel ratio is controlled.

Abstract: An engine ECU executes a program including the steps of: determining presence of abnormality in a low-pressure fuel system; ceasing an intake manifold injector when determination is made of abnormality in the low-pressure fuel system; increasing the target purge rate when the engine operation state attains an injection partaking state between an in-cylinder injector and an intake manifold injector; reducing the VVT overlap; and retarding the ignition timing.

Abstract: An engine ECU executes a program including the steps of: determining an airflow meter as abnormal when the number of times an injector is determined as abnormal (abnormality determination count C) is greater than a threshold value C(0) in all of a region where DI ratio r=100%, a region where DI ratio r=0%, and a region where 0%<DI ratio r<100%, and determining the airflow meter as normal when abnormality determination count C is smaller than the threshold value C(0) at least in any one region.

Abstract: An ignition timing control apparatus for an internal combustion engine having an in-cylinder injector for injecting a fuel into a cylinder and an intake port injector for injecting a fuel into an intake port is configured to correct a basic ignition timing, having been determined corresponding to an operation state, in accordance with a fluctuation of at least one factor affecting the combustion rate selected from a coolant temperature, an intake air temperature and an EGR (exhaust gas recirculation) amount, to set a final ignition timing. The correction amount of the ignition timing is set greater for the port injection than for the in-cylinder injection.

Abstract: The engine ECU executes the program including the step of starting a timer that counts the time elapsed from a start request, the step of detecting a temperature of the engine, and the step of calculating a DI ratio r such that the fuel is injected from the in-cylinder injector as well, when the engine is in the very cold or cold state, when there is no abnormality in the fuel system, and when starting of the engine is not yet detected even after a lapse of a predetermined period of time from the start request, only if the fuel pressure in the high-pressure system is not lower than a fuel pressure threshold value.

Abstract: An injection controller for an internal combustion engine that suppresses the accumulation of deposits on a nozzle hole of a direct injection valve. The injection controller includes the direct injection valve, which injects fuel into a cylinder, and an intake passage injection valve, which injects fuel into an intake passage. An ECU, which is connected to the direct injection and intake passage injection valves, executes a first fuel injection mode for injecting fuel with the direct injection valve and a second fuel injection mode for injecting fuel with the intake passage injection valve. The ECU switches fuel injection modes from the second fuel injection mode to the first fuel injection mode for a predetermined period when fuel is to be injected in the second fuel injection mode.

Abstract: A high pressure fuel pump boosts the pressure of fuel to discharge a quantity according to the closing period of an electromagnetic spill valve. A fuel distributor pipe receives and delivers to an in-cylinder injector the fuel discharged from the high pressure fuel pump. A fuel pressure sensor measures a fuel pressure Pt in a fuel distributor pipe. The control of open/closure of the electromagnetic spill valve according to the insufficient fuel pressure with respect to the target pressure of fuel pressure Pt is carried out in a manner similar to that of in-cylinder injection execution even during an in-cylinder injection suppressing period in which fuel is not injected from the in-cylinder injector. Accordingly, fuel pressure can be controlled at high accuracy during the in-cylinder injection suppressing period and subsequent in-cylinder injection resuming time.

Abstract: The present invention is a compression ignition internal combustion engine and method of operation which expands the load limit of quietly operating a premixed charge compression ignition (PCCI) engine by injecting a secondary fuel B, in ratios lean of stoichiometric, either into the intake air stream or directly into the cylinder to form a homogeneous fuel B and air mixture. Near top dead center of the compression stroke, a PCCI-type direct injection of fuel A event is used to initiate combustion of both fuel A and B at the proper time. At low loads the combustion mode is characterized a PCCI-type with high EGR rates. At medium loads the combustion mode is that of homogeneous combustion of fuel B coupled with PCCI combustion of fuel A. At the highest loads the engine will revert to a conventional diesel combustion mode of fuel A to maintain power density.

Abstract: An engine ECU executes a program comprising the steps of: calculating a post-warm-up steady-state port wall deposit quantity (a); calculating a shared-injection steady-state port wall deposit quantity (b) based on port wall deposit quantity (a); calculating a difference (c) in one cycle of shared-injection steady-state port wall deposit quantity (b); making a correction considering an engine temperature and an engine speed to calculate a transition correction quantity (d); and converting transition correction quantity (d) into a wave form representing temporal transition to make a wall deposit correction with higher priority on a port injection quantity.

Abstract: There are provided NOx trap catalyst to trap and release NOx based on air-fuel ratio, first fuel supply means for supplying gasoline, second fuel supply means for supplying hydrogen, engine operation detecting means for detecting engine operating condition, fuel ratio changing means for changing the ratio of gasoline and hydrogen, NOx release determining means for determining whether it is required for the NOx to be released based on a state of the trapped NOx, NOx releasing means for releasing the NOx trapped by making the air-fuel ratio rich when the NOx releasing requirement is determined, gasoline ratio increasing means for increasing the ratio of gasoline when NOx releasing requirement is determined and the air-fuel-ratio rich control is executed. Accordingly, improper vibrations or noises can be restrained from occurring when the rich air-fuel-ratio control is executed to release the trapped NOx from the NOx trap catalyst.

Abstract: In an internal combustion engine, it is first determined whether a load factor of the internal combustion engine is a specified value or more and the engine speed of the internal combustion engine is a specified speed or less. If these conditions are satisfied, fuel is injected from both of a port injection valve and a direct injection valve, and a fuel injection timing of the direct injection valve is decided so as to inject fuel from the direct injection valve during the compression stroke of the internal combustion engine.

Abstract: An internal combustion engine includes an in-cylinder injector for injecting fuel into a combustion chamber of the engine and an intake system injector for injecting fuel into an intake system connected to the combustion chamber. In a starting state of the engine, an electronic control unit (ECU) causes the in-cylinder injector to perform only the initial injection to the combustion chamber, and causes the intake system injector to perform fuel injections after the initial injection. As a result, favorable engine startability is ensured, and the emission of unburned components is suppressed in the engine starting state.

Abstract: When an internal combustion engine is stopped, a ratio of a quantity of fuel injection from an in-cylinder fuel injection valve to the total fuel injection quantity is increased and a ratio of a quantity of fuel injected from a manifold fuel injection valve to the total fuel injection quantity is decreased. Thereafter, the internal combustion engine is stopped. In this manner, a quantity of fuel adhered to an intake manifold when the internal combustion engine is stopped is reduced, and deterioration in emission can be suppressed.

Abstract: A low-octane fuel and a high-octane fuel stored in a low-octane fuel tank (5) and a high-octane fuel tank (7), both having known octane numbers, are injected from fuel injection valves (13a, 13b) into an intake port (12) at a mixing proportion that achieves a standard octane number set in accordance with the engine operation state. If knocking occurs during a predetermined steady engine operation state, the knocking is detected by a knock sensor (10b) and, corresponding to the knocking, the ignition timing is retarded from a basic ignition timing. A deviation in octane number is determined from the amount of ignition timing retardation with reference to a map, and is then corrected by the intake air pressure. On the basis of the corrected deviation in octane number, a deviation in the mixing proportion of the high-octane fuel is determined with reference to a map.