Abstract: A control device of an internal combustion engine which determines a target throttle opening degree in accordance with a required intake pipe internal pressure and which suppresses the occurrence of hunting of the throttle opening degree is provided, wherein, when the required intake pipe internal pressure becomes a predetermined pressure or more, the target throttle opening degree is determined by adding an addition-corrected throttle opening degree calculated in accordance with a difference between the required intake pipe internal pressure and the predetermined pressure based on a predetermined equation to an opening degree of a throttle valve making the intake pipe internal pressure the predetermined pressure.

Abstract: An intake amount control apparatus of an internal combustion engine in accordance with the invention includes a control portion that controls an opening amount of a throttle valve provided in an intake passageway of the internal combustion engine and operation of a lift amount changing mechanism capable of changing a lift amount of an intake valve. The control portion controls the operation of the lift amount changing mechanism so that, prior to execution of a fuel cut control at the time of an engine deceleration, the lift amount of in intake valve becomes smaller than at the time of a normal engine idle operation where the fuel cut control is not executed.

Abstract: A control device able to find the intake air flow rate in an internal combustion engine having a plurality of intake passages upstream of a throttle valve is provided. The control device finds the intake air flow rate of the internal combustion engine by converting an output voltage of each of air flow sensors provided in the intake passages to a flow rate based on a relationship between an output voltage and flow rate found in advance for each air flow sensor, correcting the obtained flow rate in accordance with temperature characteristics of each the air flow sensor, and adding the corrected flow rates to calculate a total flow rate.

Abstract: A control device for an internal combustion engine comprises an air flow meter arranged in the intake passage. The air flow meter includes a main passage and a bypass passage and detects a flow rate of air flowing through the bypass passage to detect a flow rate of air flowing through an intake passage. A current intake air flow rate is calculated based on a current throttle opening. When the rapid acceleration of the engine is in process, an air flow meter-detecting intake air flow rate, assuming that air flows through the intake passage at the current intake air flow rate, is estimated considering the pressure loss of the bypass passage of the air flow meter. When an operation other than the rapid acceleration is in process, it is estimated ignoring the pressure loss. The fuel injection amount is calculated from the estimated air flow meter-detecting intake air flow rate.

Abstract: An intake air flow detecting device is provided to an intake air passage, through which intake air flows into an internal combustion engine. Intake air flow is divided into a main passage and a bypass passage. The detecting device includes a thermal air flowmeter, a bypass flow delay information calculating means, and a response delay compensating means. The thermal air flowmeter includes a detector arranged in the bypass passage for detecting an air flow amount in the intake air passage. The bypass flow delay information calculating means calculates a bypass flow delay information representing delay in variation in a flow amount in the bypass passage with respect to variation in a flow amount in the main passage. The response delay compensating means compensates delay in response of the air flowmeter in accordance with the bypass flow delay information.

Abstract: A control device of an internal combustion engine designed to find a response time constant of a cylinder air filling amount or its equivalent value by a simpler method. The control device comprises means for setting the target opening degree, means for finding a target intake pipe pressure, means for finding a current intake pipe pressure, means for finding a throttle valve air passage flow rate, and means for finding a cylinder intake air flow rate and calculating the response time constant based on the target intake pipe pressure, the current intake pipe pressure, the throttle valve air passage flow rate, and the cylinder intake air flow rate.

Abstract: In order to provide an intake flow rate detecting apparatus of an internal combustion engine which accurately compensates for an air flow meter detection error due to intake pulsation so as to make it possible to detect an intake flow rate more accurately, regardless of the of type of flow rate control mechanism, an intake flow rate detecting apparatus according to one embodiment of the invention includes a throttle valve which is provided in an intake passage and which adjusts a rate of the air that is taken into a combustion chamber of an internal combustion engine, at least one flow rate control mechanisms which are provided between the throttle valve and the combustion chamber and which control an air flow rate between the throttle valve and the combustion chamber, and a flow rate sensor which is provided upstream of the throttle valve in the intake passage and which detects a flow rate of air flowing through the intake passage.

Abstract: A failure diagnosis for a slide sensor of a variable valve mechanism is performed when a valve working angle is at a value in the initial state. The initial state is set to a valve characteristic state where the valve working angle is at the maximum value. The maximum valve working angle corresponds to the refuge running performable region in which an engine can be started and refuge running can be performed. Therefore, even when it is difficult to adjust the valve working angle using rotation of a spiral cam due to a failure in the slide sensor, the refuge running can be performed only by maintaining the initial state by maintaining control. It is thus possible to increase reliability of the refuge running in the case where a failure has occurred in the variable valve mechanism.

Abstract: An electronic control unit corrects ignition timing according to changes in an internal EGR amount accompanying actuation of a variable valve actuation mechanism used in an internal combustion engine. The electronic control unit computes a base correction amount AVVTb based on an engine speed NE and an engine load ratio KL. The control unit multiplies the base correction amount AVVTb by the ratio of a square number of an actual valve overlap amount realOL to a square number of a target valve overlap amount tOL, thereby computing a VVT correction amount AVVT of ignition timing. As result, the engine is easily and properly controlled based on the relationship between the state of the variable valve actuation mechanism and changes in the internal EGR amount.

Abstract: An electronic control unit of an internal combustion engine computes a remaining combusted gas amount Megr1, which exists in a cylinder immediately before an intake valve is opened, based on an intake pipe pressure Pm, an engine speed NE, and an intake valve opening timing Topen. At the same time, the control unit computes a backflow combusted gas amount Megr2, which is the amount of combusted gas that flows back into the cylinder from an exhaust pipe after the intake valve is opened, based on the intake pipe pressure Pm, the engine speed NE and a valve overlap amount OL. The control unit computes the sum of the remaining combusted gas amount Megr1 and the backflow combusted gas amount Megr2, and sets the sum as an estimated internal EGR amount MegrALL. As a result, the internal EGR amount is readily and accurately estimated.

Abstract: A control device of an internal combustion engine designed to find a response time constant of a cylinder air filling amount or its equivalent value by a simpler method. The control device comprises means for setting the target opening degree, means for finding a target intake pipe pressure, means for finding a current intake pipe pressure, means for finding a throttle valve air passage flow rate, and means for finding a cylinder intake air flow rate and calculating the response time constant based on the target intake pipe pressure, the current intake pipe pressure, the throttle valve air passage flow rate, and the cylinder intake air flow rate.

Abstract: In an internal combustion engine, at least one of the pressure and temperature in an intake passage downstream of a throttle valve is calculated using an expression of a relationship established based on the law of conservation of mass among an amount of air passing the throttle valve and flowing into the intake passage, an amount of exhaust gas passing an exhaust gas flow control valve and flowing into the intake passage, and an amount of gas flowing from the intake passage into a cylinder of the engine, and an expression of a relationship established based on the law of conservation of energy among an amount of energy of the air passing the throttle valve and flowing into the intake passage, an amount of energy of the exhaust gas passing the exhaust gas flow control valve and flowing into the intake passage, and an amount of energy of the gas flowing from the intake passage into the cylinder of the engine.

Abstract: A device for estimating the amount of intake air of an internal combustion engine comprising intake pipe pressure calculation means for calculating an intake pipe pressure, at this time, downstream of the throttle valve, and intake air amount calculation means for calculating the amount of intake air, at this time, based on the intake pipe pressure at this time calculated by said intake pipe pressure calculation means, is provided. The intake pipe pressure calculation means calculates the intake pipe pressure at this time by using the intake pipe pressure calculated at the last time and the amount of air passing through the throttle valve at the last time calculated by means for calculating the amount of air passing through the throttle valve.

Abstract: In an internal combustion engine wherein a valve timing can be changed in at least two stages and wherein an exhaust gas recirculation passage provided with a control valve is connected to an intake pipe downstream of a throttle valve, there is provided an intake air amount estimation apparatus that estimates, on the basis of an intake pipe pressure, an amount of intake air drawn via the throttle valve. An amount of recirculated exhaust gas flowing past the control valve having a specific opening degree based on an intake pipe pressure in the case of the first valve timing is calculated as an intake exhaust gas amount. On the assumption that this intake exhaust gas amount remains unchanged irrespective of a valve timing, an intake air amount in the case of the second valve timing is calculated.

Abstract: An electronic control unit corrects ignition timing according to changes in an internal EGR amount accompanying actuation of a variable valve actuation mechanism used in an internal combustion engine. The electronic control unit computes a base correction amount AVVTb based on an engine speed NE and an engine load ratio KL. The control unit multiplies the base correction amount AVVTb by the ratio of a square number of an actual valve overlap amount realOL to a square number of a target valve overlap amount tOL, thereby computing a VVT correction amount AVVT of ignition timing. As result, the engine is easily and properly controlled based on the relationship between the state of the variable valve actuation mechanism and changes in the internal EGR amount.

Abstract: An electronic control unit of an internal combustion engine computes a remaining combusted gas amount Megr1, which exists in a cylinder immediately before an intake valve is opened, based on an intake pipe pressure Pm, an engine speed NE, and an intake valve opening timing Topen. At the same time, the control unit computes a backflow combusted gas amount Megr2, which is the amount of combusted gas that flows back into the cylinder from an exhaust pipe after the intake valve is opened, based on the intake pipe pressure Pm, the engine speed NE and a valve overlap amount OL. The control unit computes the sum of the remaining combusted gas amount Megr1 and the backflow combusted gas amount Megr2, and sets the sum as an estimated internal EGR amount MegrALL. As a result, the internal EGR amount is readily and accurately estimated.

Abstract: In an internal combustion engine, at least one of the pressure and temperature in an intake passage downstream of a throttle valve is calculated using an expression of a relationship established based on the law of conservation of mass among an amount of air passing the throttle valve and flowing into the intake passage, an amount of exhaust gas passing an exhaust gas flow control valve and flowing into the intake passage, and an amount of gas flowing from the intake passage into a cylinder of the engine, and an expression of a relationship established based on the law of conservation of energy among an amount of energy of the air passing the throttle valve and flowing into the intake passage, an amount of energy of the exhaust gas passing the exhaust gas flow control valve and flowing into the intake passage, and an amount of energy of the gas flowing from the intake passage into the cylinder of the engine.

Abstract: In an internal combustion engine wherein a valve timing can be changed in at least two stages and wherein an exhaust gas recirculation passage provided with a control valve is connected to an intake pipe downstream of a throttle valve, there is provided an intake air amount estimation apparatus that estimates, on the basis of an intake pipe pressure, an amount of intake air drawn via the throttle valve. An amount of recirculated exhaust gas flowing past the control valve having a specific opening degree based on an intake pipe pressure in the case of the first valve timing is calculated as an intake exhaust gas amount. On the assumption that this intake exhaust gas amount remains unchanged irrespective of a valve timing, an intake air amount in the case of the second valve timing is calculated.

Abstract: A device for estimating the amount of intake air of an internal combustion engine comprising intake pipe pressure calculation means for calculating an intake pipe pressure, at this time, downstream of the throttle valve, and intake air amount calculation means for calculating the amount of intake air, at this time, based on the intake pipe pressure at this time calculated by said intake pipe pressure calculation means, is provided. The intake pipe pressure calculation means calculates the intake pipe pressure at this time by using the intake pipe pressure calculated at the last time and the amount of air passing through the throttle valve at the last time calculated by means for calculating the amount of air passing through the throttle valve.

Abstract: An intake pressure computing apparatus and a method for the same compute an intake pipe pressure P0 based on a sum of a throttle passing air amount QA0 calculated based on at least a throttle opening and a flow of purge air that flows into an intake pipe through a purge passage, or a purge flow rate QP, and compute an intake pipe pressure P3 using an intake air amount QA based on an output from an air flow meter. An intake air amount computing apparatus and a method for the same compute an amount of air drawn into an engine, or an intake air amount, based on the intake pipe pressure P0 and the intake pipe pressure P3.